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fs/namespace.c
97 KB
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// SPDX-License-Identifier: GPL-2.0-only |
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/* * linux/fs/namespace.c * * (C) Copyright Al Viro 2000, 2001 |
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* * Based on code from fs/super.c, copyright Linus Torvalds and others. * Heavily rewritten. */ |
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#include <linux/syscalls.h> |
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#include <linux/export.h> |
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#include <linux/capability.h> |
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#include <linux/mnt_namespace.h> |
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#include <linux/user_namespace.h> |
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#include <linux/namei.h> #include <linux/security.h> |
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#include <linux/cred.h> |
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#include <linux/idr.h> |
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#include <linux/init.h> /* init_rootfs */ |
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#include <linux/fs_struct.h> /* get_fs_root et.al. */ #include <linux/fsnotify.h> /* fsnotify_vfsmount_delete */ |
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#include <linux/file.h> |
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#include <linux/uaccess.h> |
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#include <linux/proc_ns.h> |
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#include <linux/magic.h> |
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#include <linux/memblock.h> |
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#include <linux/task_work.h> |
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#include <linux/sched/task.h> |
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#include <uapi/linux/mount.h> |
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#include <linux/fs_context.h> |
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#include <linux/shmem_fs.h> |
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|
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#include "pnode.h" |
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#include "internal.h" |
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/* Maximum number of mounts in a mount namespace */ unsigned int sysctl_mount_max __read_mostly = 100000; |
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static unsigned int m_hash_mask __read_mostly; static unsigned int m_hash_shift __read_mostly; static unsigned int mp_hash_mask __read_mostly; static unsigned int mp_hash_shift __read_mostly; static __initdata unsigned long mhash_entries; static int __init set_mhash_entries(char *str) { if (!str) return 0; mhash_entries = simple_strtoul(str, &str, 0); return 1; } __setup("mhash_entries=", set_mhash_entries); static __initdata unsigned long mphash_entries; static int __init set_mphash_entries(char *str) { if (!str) return 0; mphash_entries = simple_strtoul(str, &str, 0); return 1; } __setup("mphash_entries=", set_mphash_entries); |
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static u64 event; |
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static DEFINE_IDA(mnt_id_ida); |
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static DEFINE_IDA(mnt_group_ida); |
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static struct hlist_head *mount_hashtable __read_mostly; |
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static struct hlist_head *mountpoint_hashtable __read_mostly; |
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static struct kmem_cache *mnt_cache __read_mostly; |
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static DECLARE_RWSEM(namespace_sem); |
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static HLIST_HEAD(unmounted); /* protected by namespace_sem */ static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */ |
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/* /sys/fs */ |
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struct kobject *fs_kobj; EXPORT_SYMBOL_GPL(fs_kobj); |
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/* * vfsmount lock may be taken for read to prevent changes to the * vfsmount hash, ie. during mountpoint lookups or walking back * up the tree. * * It should be taken for write in all cases where the vfsmount * tree or hash is modified or when a vfsmount structure is modified. */ |
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__cacheline_aligned_in_smp DEFINE_SEQLOCK(mount_lock); |
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|
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static inline struct hlist_head *m_hash(struct vfsmount *mnt, struct dentry *dentry) |
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{ |
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unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES); tmp += ((unsigned long)dentry / L1_CACHE_BYTES); |
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tmp = tmp + (tmp >> m_hash_shift); return &mount_hashtable[tmp & m_hash_mask]; } static inline struct hlist_head *mp_hash(struct dentry *dentry) { unsigned long tmp = ((unsigned long)dentry / L1_CACHE_BYTES); tmp = tmp + (tmp >> mp_hash_shift); return &mountpoint_hashtable[tmp & mp_hash_mask]; |
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} |
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static int mnt_alloc_id(struct mount *mnt) |
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{ |
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int res = ida_alloc(&mnt_id_ida, GFP_KERNEL); if (res < 0) return res; mnt->mnt_id = res; return 0; |
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} |
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static void mnt_free_id(struct mount *mnt) |
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{ |
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ida_free(&mnt_id_ida, mnt->mnt_id); |
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} |
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/* * Allocate a new peer group ID |
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*/ |
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static int mnt_alloc_group_id(struct mount *mnt) |
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{ |
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int res = ida_alloc_min(&mnt_group_ida, 1, GFP_KERNEL); |
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|
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if (res < 0) return res; mnt->mnt_group_id = res; return 0; |
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} /* * Release a peer group ID */ |
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void mnt_release_group_id(struct mount *mnt) |
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{ |
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ida_free(&mnt_group_ida, mnt->mnt_group_id); |
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mnt->mnt_group_id = 0; |
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} |
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/* * vfsmount lock must be held for read */ |
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static inline void mnt_add_count(struct mount *mnt, int n) |
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{ #ifdef CONFIG_SMP |
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this_cpu_add(mnt->mnt_pcp->mnt_count, n); |
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#else preempt_disable(); |
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mnt->mnt_count += n; |
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preempt_enable(); #endif } |
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/* * vfsmount lock must be held for write */ |
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unsigned int mnt_get_count(struct mount *mnt) |
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{ #ifdef CONFIG_SMP |
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unsigned int count = 0; |
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int cpu; for_each_possible_cpu(cpu) { |
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count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_count; |
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} return count; #else |
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return mnt->mnt_count; |
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#endif } |
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static struct mount *alloc_vfsmnt(const char *name) |
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{ |
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struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL); if (mnt) { |
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int err; |
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err = mnt_alloc_id(mnt); |
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if (err) goto out_free_cache; if (name) { |
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mnt->mnt_devname = kstrdup_const(name, GFP_KERNEL); |
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if (!mnt->mnt_devname) |
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goto out_free_id; |
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} |
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#ifdef CONFIG_SMP |
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mnt->mnt_pcp = alloc_percpu(struct mnt_pcp); if (!mnt->mnt_pcp) |
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goto out_free_devname; |
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this_cpu_add(mnt->mnt_pcp->mnt_count, 1); |
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#else |
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mnt->mnt_count = 1; mnt->mnt_writers = 0; |
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#endif |
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INIT_HLIST_NODE(&mnt->mnt_hash); |
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INIT_LIST_HEAD(&mnt->mnt_child); INIT_LIST_HEAD(&mnt->mnt_mounts); INIT_LIST_HEAD(&mnt->mnt_list); INIT_LIST_HEAD(&mnt->mnt_expire); INIT_LIST_HEAD(&mnt->mnt_share); INIT_LIST_HEAD(&mnt->mnt_slave_list); INIT_LIST_HEAD(&mnt->mnt_slave); |
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INIT_HLIST_NODE(&mnt->mnt_mp_list); |
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INIT_LIST_HEAD(&mnt->mnt_umounting); |
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INIT_HLIST_HEAD(&mnt->mnt_stuck_children); |
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} |
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return mnt; |
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|
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#ifdef CONFIG_SMP out_free_devname: |
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kfree_const(mnt->mnt_devname); |
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#endif |
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out_free_id: |
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mnt_free_id(mnt); |
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out_free_cache: |
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kmem_cache_free(mnt_cache, mnt); |
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return NULL; |
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} |
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/* * Most r/o checks on a fs are for operations that take * discrete amounts of time, like a write() or unlink(). * We must keep track of when those operations start * (for permission checks) and when they end, so that * we can determine when writes are able to occur to * a filesystem. */ |
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/* * __mnt_is_readonly: check whether a mount is read-only * @mnt: the mount to check for its write status * * This shouldn't be used directly ouside of the VFS. * It does not guarantee that the filesystem will stay * r/w, just that it is right *now*. This can not and * should not be used in place of IS_RDONLY(inode). * mnt_want/drop_write() will _keep_ the filesystem * r/w. */ |
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bool __mnt_is_readonly(struct vfsmount *mnt) |
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{ |
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return (mnt->mnt_flags & MNT_READONLY) || sb_rdonly(mnt->mnt_sb); |
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} EXPORT_SYMBOL_GPL(__mnt_is_readonly); |
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static inline void mnt_inc_writers(struct mount *mnt) |
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{ #ifdef CONFIG_SMP |
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this_cpu_inc(mnt->mnt_pcp->mnt_writers); |
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#else |
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mnt->mnt_writers++; |
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#endif } |
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|
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static inline void mnt_dec_writers(struct mount *mnt) |
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{ |
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#ifdef CONFIG_SMP |
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this_cpu_dec(mnt->mnt_pcp->mnt_writers); |
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#else |
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mnt->mnt_writers--; |
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#endif |
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} |
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|
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static unsigned int mnt_get_writers(struct mount *mnt) |
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{ |
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#ifdef CONFIG_SMP unsigned int count = 0; |
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int cpu; |
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for_each_possible_cpu(cpu) { |
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count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_writers; |
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} |
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|
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return count; #else return mnt->mnt_writers; #endif |
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} |
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static int mnt_is_readonly(struct vfsmount *mnt) { if (mnt->mnt_sb->s_readonly_remount) return 1; /* Order wrt setting s_flags/s_readonly_remount in do_remount() */ smp_rmb(); return __mnt_is_readonly(mnt); } |
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/* |
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* Most r/o & frozen checks on a fs are for operations that take discrete * amounts of time, like a write() or unlink(). We must keep track of when * those operations start (for permission checks) and when they end, so that we * can determine when writes are able to occur to a filesystem. |
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*/ |
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/** |
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* __mnt_want_write - get write access to a mount without freeze protection |
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* @m: the mount on which to take a write |
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* |
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* This tells the low-level filesystem that a write is about to be performed to * it, and makes sure that writes are allowed (mnt it read-write) before * returning success. This operation does not protect against filesystem being * frozen. When the write operation is finished, __mnt_drop_write() must be * called. This is effectively a refcount. |
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*/ |
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int __mnt_want_write(struct vfsmount *m) |
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{ |
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struct mount *mnt = real_mount(m); |
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int ret = 0; |
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|
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preempt_disable(); |
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mnt_inc_writers(mnt); |
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/* |
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* The store to mnt_inc_writers must be visible before we pass |
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* MNT_WRITE_HOLD loop below, so that the slowpath can see our * incremented count after it has set MNT_WRITE_HOLD. */ smp_mb(); |
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while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) |
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cpu_relax(); /* * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will * be set to match its requirements. So we must not load that until * MNT_WRITE_HOLD is cleared. */ smp_rmb(); |
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if (mnt_is_readonly(m)) { |
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mnt_dec_writers(mnt); |
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ret = -EROFS; |
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} |
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preempt_enable(); |
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return ret; } /** * mnt_want_write - get write access to a mount * @m: the mount on which to take a write * * This tells the low-level filesystem that a write is about to be performed to * it, and makes sure that writes are allowed (mount is read-write, filesystem * is not frozen) before returning success. When the write operation is * finished, mnt_drop_write() must be called. This is effectively a refcount. */ int mnt_want_write(struct vfsmount *m) { int ret; sb_start_write(m->mnt_sb); ret = __mnt_want_write(m); if (ret) sb_end_write(m->mnt_sb); |
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return ret; |
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} EXPORT_SYMBOL_GPL(mnt_want_write); /** |
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* mnt_clone_write - get write access to a mount * @mnt: the mount on which to take a write * * This is effectively like mnt_want_write, except * it must only be used to take an extra write reference * on a mountpoint that we already know has a write reference * on it. This allows some optimisation. * * After finished, mnt_drop_write must be called as usual to * drop the reference. */ int mnt_clone_write(struct vfsmount *mnt) { /* superblock may be r/o */ if (__mnt_is_readonly(mnt)) return -EROFS; preempt_disable(); |
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mnt_inc_writers(real_mount(mnt)); |
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preempt_enable(); return 0; } EXPORT_SYMBOL_GPL(mnt_clone_write); /** |
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* __mnt_want_write_file - get write access to a file's mount |
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* @file: the file who's mount on which to take a write * |
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* This is like __mnt_want_write, but it takes a file and can |
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* do some optimisations if the file is open for write already */ |
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int __mnt_want_write_file(struct file *file) |
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{ |
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if (!(file->f_mode & FMODE_WRITER)) |
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return __mnt_want_write(file->f_path.mnt); |
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else return mnt_clone_write(file->f_path.mnt); } |
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/** |
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386 387 388 389 390 |
* mnt_want_write_file - get write access to a file's mount * @file: the file who's mount on which to take a write * * This is like mnt_want_write, but it takes a file and can * do some optimisations if the file is open for write already |
7c6893e3c ovl: don't allow ... |
391 392 393 394 |
*/ int mnt_want_write_file(struct file *file) { int ret; |
a6795a585 vfs: fix freeze p... |
395 |
sb_start_write(file_inode(file)->i_sb); |
eb04c2828 fs: Add freezing ... |
396 397 |
ret = __mnt_want_write_file(file); if (ret) |
a6795a585 vfs: fix freeze p... |
398 |
sb_end_write(file_inode(file)->i_sb); |
7c6893e3c ovl: don't allow ... |
399 400 |
return ret; } |
96029c4e0 fs: introduce mnt... |
401 402 403 |
EXPORT_SYMBOL_GPL(mnt_want_write_file); /** |
eb04c2828 fs: Add freezing ... |
404 |
* __mnt_drop_write - give up write access to a mount |
8366025eb [PATCH] r/o bind ... |
405 406 407 408 |
* @mnt: the mount on which to give up write access * * Tells the low-level filesystem that we are done * performing writes to it. Must be matched with |
eb04c2828 fs: Add freezing ... |
409 |
* __mnt_want_write() call above. |
8366025eb [PATCH] r/o bind ... |
410 |
*/ |
eb04c2828 fs: Add freezing ... |
411 |
void __mnt_drop_write(struct vfsmount *mnt) |
8366025eb [PATCH] r/o bind ... |
412 |
{ |
d3ef3d735 fs: mnt_want_writ... |
413 |
preempt_disable(); |
83adc7532 vfs: spread struc... |
414 |
mnt_dec_writers(real_mount(mnt)); |
d3ef3d735 fs: mnt_want_writ... |
415 |
preempt_enable(); |
8366025eb [PATCH] r/o bind ... |
416 |
} |
eb04c2828 fs: Add freezing ... |
417 418 419 420 421 422 423 424 425 426 427 428 429 430 |
/** * mnt_drop_write - give up write access to a mount * @mnt: the mount on which to give up write access * * Tells the low-level filesystem that we are done performing writes to it and * also allows filesystem to be frozen again. Must be matched with * mnt_want_write() call above. */ void mnt_drop_write(struct vfsmount *mnt) { __mnt_drop_write(mnt); sb_end_write(mnt->mnt_sb); } |
8366025eb [PATCH] r/o bind ... |
431 |
EXPORT_SYMBOL_GPL(mnt_drop_write); |
eb04c2828 fs: Add freezing ... |
432 433 434 435 |
void __mnt_drop_write_file(struct file *file) { __mnt_drop_write(file->f_path.mnt); } |
7c6893e3c ovl: don't allow ... |
436 437 |
void mnt_drop_write_file(struct file *file) { |
a6795a585 vfs: fix freeze p... |
438 |
__mnt_drop_write_file(file); |
7c6893e3c ovl: don't allow ... |
439 440 |
sb_end_write(file_inode(file)->i_sb); } |
2a79f17e4 vfs: mnt_drop_wri... |
441 |
EXPORT_SYMBOL(mnt_drop_write_file); |
83adc7532 vfs: spread struc... |
442 |
static int mnt_make_readonly(struct mount *mnt) |
8366025eb [PATCH] r/o bind ... |
443 |
{ |
3d733633a [PATCH] r/o bind ... |
444 |
int ret = 0; |
719ea2fbb new helpers: lock... |
445 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
446 |
mnt->mnt.mnt_flags |= MNT_WRITE_HOLD; |
3d733633a [PATCH] r/o bind ... |
447 |
/* |
d3ef3d735 fs: mnt_want_writ... |
448 449 |
* After storing MNT_WRITE_HOLD, we'll read the counters. This store * should be visible before we do. |
3d733633a [PATCH] r/o bind ... |
450 |
*/ |
d3ef3d735 fs: mnt_want_writ... |
451 |
smp_mb(); |
3d733633a [PATCH] r/o bind ... |
452 |
/* |
d3ef3d735 fs: mnt_want_writ... |
453 454 455 456 457 458 459 460 461 462 463 464 465 466 |
* With writers on hold, if this value is zero, then there are * definitely no active writers (although held writers may subsequently * increment the count, they'll have to wait, and decrement it after * seeing MNT_READONLY). * * It is OK to have counter incremented on one CPU and decremented on * another: the sum will add up correctly. The danger would be when we * sum up each counter, if we read a counter before it is incremented, * but then read another CPU's count which it has been subsequently * decremented from -- we would see more decrements than we should. * MNT_WRITE_HOLD protects against this scenario, because * mnt_want_write first increments count, then smp_mb, then spins on * MNT_WRITE_HOLD, so it can't be decremented by another CPU while * we're counting up here. |
3d733633a [PATCH] r/o bind ... |
467 |
*/ |
c6653a838 fs: rename vfsmou... |
468 |
if (mnt_get_writers(mnt) > 0) |
d3ef3d735 fs: mnt_want_writ... |
469 470 |
ret = -EBUSY; else |
83adc7532 vfs: spread struc... |
471 |
mnt->mnt.mnt_flags |= MNT_READONLY; |
d3ef3d735 fs: mnt_want_writ... |
472 473 474 475 476 |
/* * MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers * that become unheld will see MNT_READONLY. */ smp_wmb(); |
83adc7532 vfs: spread struc... |
477 |
mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD; |
719ea2fbb new helpers: lock... |
478 |
unlock_mount_hash(); |
3d733633a [PATCH] r/o bind ... |
479 |
return ret; |
8366025eb [PATCH] r/o bind ... |
480 |
} |
8366025eb [PATCH] r/o bind ... |
481 |
|
43f5e655e vfs: Separate cha... |
482 |
static int __mnt_unmake_readonly(struct mount *mnt) |
2e4b7fcd9 [PATCH] r/o bind ... |
483 |
{ |
719ea2fbb new helpers: lock... |
484 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
485 |
mnt->mnt.mnt_flags &= ~MNT_READONLY; |
719ea2fbb new helpers: lock... |
486 |
unlock_mount_hash(); |
43f5e655e vfs: Separate cha... |
487 |
return 0; |
2e4b7fcd9 [PATCH] r/o bind ... |
488 |
} |
4ed5e82fe vfs: protect remo... |
489 490 491 492 |
int sb_prepare_remount_readonly(struct super_block *sb) { struct mount *mnt; int err = 0; |
8e8b87964 vfs: prevent remo... |
493 494 495 |
/* Racy optimization. Recheck the counter under MNT_WRITE_HOLD */ if (atomic_long_read(&sb->s_remove_count)) return -EBUSY; |
719ea2fbb new helpers: lock... |
496 |
lock_mount_hash(); |
4ed5e82fe vfs: protect remo... |
497 498 499 500 501 502 503 504 505 506 |
list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) { if (!(mnt->mnt.mnt_flags & MNT_READONLY)) { mnt->mnt.mnt_flags |= MNT_WRITE_HOLD; smp_mb(); if (mnt_get_writers(mnt) > 0) { err = -EBUSY; break; } } } |
8e8b87964 vfs: prevent remo... |
507 508 |
if (!err && atomic_long_read(&sb->s_remove_count)) err = -EBUSY; |
4ed5e82fe vfs: protect remo... |
509 510 511 512 513 514 515 516 |
if (!err) { sb->s_readonly_remount = 1; smp_wmb(); } list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) { if (mnt->mnt.mnt_flags & MNT_WRITE_HOLD) mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD; } |
719ea2fbb new helpers: lock... |
517 |
unlock_mount_hash(); |
4ed5e82fe vfs: protect remo... |
518 519 520 |
return err; } |
b105e270b vfs: spread struc... |
521 |
static void free_vfsmnt(struct mount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
522 |
{ |
fcc139ae2 fs/namespace: con... |
523 |
kfree_const(mnt->mnt_devname); |
d3ef3d735 fs: mnt_want_writ... |
524 |
#ifdef CONFIG_SMP |
68e8a9fea vfs: all counters... |
525 |
free_percpu(mnt->mnt_pcp); |
d3ef3d735 fs: mnt_want_writ... |
526 |
#endif |
b105e270b vfs: spread struc... |
527 |
kmem_cache_free(mnt_cache, mnt); |
1da177e4c Linux-2.6.12-rc2 |
528 |
} |
8ffcb32e0 VFS: Make delayed... |
529 530 531 532 |
static void delayed_free_vfsmnt(struct rcu_head *head) { free_vfsmnt(container_of(head, struct mount, mnt_rcu)); } |
48a066e72 RCU'd vfsmounts |
533 |
/* call under rcu_read_lock */ |
294d71ff2 new helper: __leg... |
534 |
int __legitimize_mnt(struct vfsmount *bastard, unsigned seq) |
48a066e72 RCU'd vfsmounts |
535 536 537 |
{ struct mount *mnt; if (read_seqretry(&mount_lock, seq)) |
294d71ff2 new helper: __leg... |
538 |
return 1; |
48a066e72 RCU'd vfsmounts |
539 |
if (bastard == NULL) |
294d71ff2 new helper: __leg... |
540 |
return 0; |
48a066e72 RCU'd vfsmounts |
541 542 |
mnt = real_mount(bastard); mnt_add_count(mnt, 1); |
119e1ef80 fix __legitimize_... |
543 |
smp_mb(); // see mntput_no_expire() |
48a066e72 RCU'd vfsmounts |
544 |
if (likely(!read_seqretry(&mount_lock, seq))) |
294d71ff2 new helper: __leg... |
545 |
return 0; |
48a066e72 RCU'd vfsmounts |
546 547 |
if (bastard->mnt_flags & MNT_SYNC_UMOUNT) { mnt_add_count(mnt, -1); |
294d71ff2 new helper: __leg... |
548 549 |
return 1; } |
119e1ef80 fix __legitimize_... |
550 551 552 553 554 555 556 557 |
lock_mount_hash(); if (unlikely(bastard->mnt_flags & MNT_DOOMED)) { mnt_add_count(mnt, -1); unlock_mount_hash(); return 1; } unlock_mount_hash(); /* caller will mntput() */ |
294d71ff2 new helper: __leg... |
558 559 560 561 562 563 564 565 566 567 568 569 570 |
return -1; } /* call under rcu_read_lock */ bool legitimize_mnt(struct vfsmount *bastard, unsigned seq) { int res = __legitimize_mnt(bastard, seq); if (likely(!res)) return true; if (unlikely(res < 0)) { rcu_read_unlock(); mntput(bastard); rcu_read_lock(); |
48a066e72 RCU'd vfsmounts |
571 |
} |
48a066e72 RCU'd vfsmounts |
572 573 |
return false; } |
1da177e4c Linux-2.6.12-rc2 |
574 |
/* |
474279dc0 split __lookup_mn... |
575 |
* find the first mount at @dentry on vfsmount @mnt. |
48a066e72 RCU'd vfsmounts |
576 |
* call under rcu_read_lock() |
1da177e4c Linux-2.6.12-rc2 |
577 |
*/ |
474279dc0 split __lookup_mn... |
578 |
struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4c Linux-2.6.12-rc2 |
579 |
{ |
38129a13e switch mnt_hash t... |
580 |
struct hlist_head *head = m_hash(mnt, dentry); |
474279dc0 split __lookup_mn... |
581 |
struct mount *p; |
38129a13e switch mnt_hash t... |
582 |
hlist_for_each_entry_rcu(p, head, mnt_hash) |
474279dc0 split __lookup_mn... |
583 584 585 586 587 588 |
if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) return p; return NULL; } /* |
f015f1267 VFS: Comment moun... |
589 590 591 592 593 594 595 596 597 598 599 600 601 602 |
* lookup_mnt - Return the first child mount mounted at path * * "First" means first mounted chronologically. If you create the * following mounts: * * mount /dev/sda1 /mnt * mount /dev/sda2 /mnt * mount /dev/sda3 /mnt * * Then lookup_mnt() on the base /mnt dentry in the root mount will * return successively the root dentry and vfsmount of /dev/sda1, then * /dev/sda2, then /dev/sda3, then NULL. * * lookup_mnt takes a reference to the found vfsmount. |
a05964f39 [PATCH] shared mo... |
603 |
*/ |
ca71cf71e namespace.c: cons... |
604 |
struct vfsmount *lookup_mnt(const struct path *path) |
a05964f39 [PATCH] shared mo... |
605 |
{ |
c71053659 vfs: spread struc... |
606 |
struct mount *child_mnt; |
48a066e72 RCU'd vfsmounts |
607 608 |
struct vfsmount *m; unsigned seq; |
99b7db7b8 fs: brlock vfsmou... |
609 |
|
48a066e72 RCU'd vfsmounts |
610 611 612 613 614 615 616 617 |
rcu_read_lock(); do { seq = read_seqbegin(&mount_lock); child_mnt = __lookup_mnt(path->mnt, path->dentry); m = child_mnt ? &child_mnt->mnt : NULL; } while (!legitimize_mnt(m, seq)); rcu_read_unlock(); return m; |
a05964f39 [PATCH] shared mo... |
618 |
} |
7af1364ff vfs: Don't allow ... |
619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 |
/* * __is_local_mountpoint - Test to see if dentry is a mountpoint in the * current mount namespace. * * The common case is dentries are not mountpoints at all and that * test is handled inline. For the slow case when we are actually * dealing with a mountpoint of some kind, walk through all of the * mounts in the current mount namespace and test to see if the dentry * is a mountpoint. * * The mount_hashtable is not usable in the context because we * need to identify all mounts that may be in the current mount * namespace not just a mount that happens to have some specified * parent mount. */ bool __is_local_mountpoint(struct dentry *dentry) { struct mnt_namespace *ns = current->nsproxy->mnt_ns; struct mount *mnt; bool is_covered = false; if (!d_mountpoint(dentry)) goto out; down_read(&namespace_sem); list_for_each_entry(mnt, &ns->list, mnt_list) { is_covered = (mnt->mnt_mountpoint == dentry); if (is_covered) break; } up_read(&namespace_sem); out: return is_covered; } |
e2dfa9354 vfs: factor out l... |
653 |
static struct mountpoint *lookup_mountpoint(struct dentry *dentry) |
84d17192d get rid of full-h... |
654 |
{ |
0818bf27c resizable namespa... |
655 |
struct hlist_head *chain = mp_hash(dentry); |
84d17192d get rid of full-h... |
656 |
struct mountpoint *mp; |
0818bf27c resizable namespa... |
657 |
hlist_for_each_entry(mp, chain, m_hash) { |
84d17192d get rid of full-h... |
658 |
if (mp->m_dentry == dentry) { |
84d17192d get rid of full-h... |
659 660 661 662 |
mp->m_count++; return mp; } } |
e2dfa9354 vfs: factor out l... |
663 664 |
return NULL; } |
3895dbf89 mnt: Protect the ... |
665 |
static struct mountpoint *get_mountpoint(struct dentry *dentry) |
e2dfa9354 vfs: factor out l... |
666 |
{ |
3895dbf89 mnt: Protect the ... |
667 |
struct mountpoint *mp, *new = NULL; |
e2dfa9354 vfs: factor out l... |
668 |
int ret; |
84d17192d get rid of full-h... |
669 |
|
3895dbf89 mnt: Protect the ... |
670 |
if (d_mountpoint(dentry)) { |
1e9c75fb9 mnt: fix __detach... |
671 672 673 |
/* might be worth a WARN_ON() */ if (d_unlinked(dentry)) return ERR_PTR(-ENOENT); |
3895dbf89 mnt: Protect the ... |
674 675 676 677 678 679 680 681 682 683 684 |
mountpoint: read_seqlock_excl(&mount_lock); mp = lookup_mountpoint(dentry); read_sequnlock_excl(&mount_lock); if (mp) goto done; } if (!new) new = kmalloc(sizeof(struct mountpoint), GFP_KERNEL); if (!new) |
84d17192d get rid of full-h... |
685 |
return ERR_PTR(-ENOMEM); |
3895dbf89 mnt: Protect the ... |
686 687 |
/* Exactly one processes may set d_mounted */ |
eed810076 vfs: check unlink... |
688 |
ret = d_set_mounted(dentry); |
eed810076 vfs: check unlink... |
689 |
|
3895dbf89 mnt: Protect the ... |
690 691 692 693 694 695 696 697 698 699 700 |
/* Someone else set d_mounted? */ if (ret == -EBUSY) goto mountpoint; /* The dentry is not available as a mountpoint? */ mp = ERR_PTR(ret); if (ret) goto done; /* Add the new mountpoint to the hash table */ read_seqlock_excl(&mount_lock); |
4edbe133f make struct mount... |
701 |
new->m_dentry = dget(dentry); |
3895dbf89 mnt: Protect the ... |
702 703 704 705 706 707 708 709 710 |
new->m_count = 1; hlist_add_head(&new->m_hash, mp_hash(dentry)); INIT_HLIST_HEAD(&new->m_list); read_sequnlock_excl(&mount_lock); mp = new; new = NULL; done: kfree(new); |
84d17192d get rid of full-h... |
711 712 |
return mp; } |
4edbe133f make struct mount... |
713 714 715 716 717 |
/* * vfsmount lock must be held. Additionally, the caller is responsible * for serializing calls for given disposal list. */ static void __put_mountpoint(struct mountpoint *mp, struct list_head *list) |
84d17192d get rid of full-h... |
718 719 720 |
{ if (!--mp->m_count) { struct dentry *dentry = mp->m_dentry; |
0a5eb7c81 vfs: Keep a list ... |
721 |
BUG_ON(!hlist_empty(&mp->m_list)); |
84d17192d get rid of full-h... |
722 723 724 |
spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_MOUNTED; spin_unlock(&dentry->d_lock); |
4edbe133f make struct mount... |
725 |
dput_to_list(dentry, list); |
0818bf27c resizable namespa... |
726 |
hlist_del(&mp->m_hash); |
84d17192d get rid of full-h... |
727 728 729 |
kfree(mp); } } |
4edbe133f make struct mount... |
730 731 732 733 734 |
/* called with namespace_lock and vfsmount lock */ static void put_mountpoint(struct mountpoint *mp) { __put_mountpoint(mp, &ex_mountpoints); } |
143c8c91c vfs: mnt_ns moved... |
735 |
static inline int check_mnt(struct mount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
736 |
{ |
6b3286ed1 [PATCH] rename st... |
737 |
return mnt->mnt_ns == current->nsproxy->mnt_ns; |
1da177e4c Linux-2.6.12-rc2 |
738 |
} |
99b7db7b8 fs: brlock vfsmou... |
739 740 741 |
/* * vfsmount lock must be held for write */ |
6b3286ed1 [PATCH] rename st... |
742 |
static void touch_mnt_namespace(struct mnt_namespace *ns) |
5addc5dd8 [PATCH] make /pro... |
743 744 745 746 747 748 |
{ if (ns) { ns->event = ++event; wake_up_interruptible(&ns->poll); } } |
99b7db7b8 fs: brlock vfsmou... |
749 750 751 |
/* * vfsmount lock must be held for write */ |
6b3286ed1 [PATCH] rename st... |
752 |
static void __touch_mnt_namespace(struct mnt_namespace *ns) |
5addc5dd8 [PATCH] make /pro... |
753 754 755 756 757 758 |
{ if (ns && ns->event != event) { ns->event = event; wake_up_interruptible(&ns->poll); } } |
99b7db7b8 fs: brlock vfsmou... |
759 760 761 |
/* * vfsmount lock must be held for write */ |
e4e59906c fs/namespace.c: s... |
762 |
static struct mountpoint *unhash_mnt(struct mount *mnt) |
419148da6 vfs: spread struc... |
763 |
{ |
e4e59906c fs/namespace.c: s... |
764 |
struct mountpoint *mp; |
0714a5338 vfs: now it can b... |
765 |
mnt->mnt_parent = mnt; |
a73324da7 vfs: move mnt_mou... |
766 |
mnt->mnt_mountpoint = mnt->mnt.mnt_root; |
6b41d536f vfs: take mnt_chi... |
767 |
list_del_init(&mnt->mnt_child); |
38129a13e switch mnt_hash t... |
768 |
hlist_del_init_rcu(&mnt->mnt_hash); |
0a5eb7c81 vfs: Keep a list ... |
769 |
hlist_del_init(&mnt->mnt_mp_list); |
e4e59906c fs/namespace.c: s... |
770 |
mp = mnt->mnt_mp; |
84d17192d get rid of full-h... |
771 |
mnt->mnt_mp = NULL; |
e4e59906c fs/namespace.c: s... |
772 |
return mp; |
7bdb11de8 mnt: Factor out u... |
773 774 775 776 777 |
} /* * vfsmount lock must be held for write */ |
6a46c5735 mnt: Factor umoun... |
778 779 |
static void umount_mnt(struct mount *mnt) { |
e4e59906c fs/namespace.c: s... |
780 |
put_mountpoint(unhash_mnt(mnt)); |
6a46c5735 mnt: Factor umoun... |
781 782 783 784 785 |
} /* * vfsmount lock must be held for write */ |
84d17192d get rid of full-h... |
786 787 |
void mnt_set_mountpoint(struct mount *mnt, struct mountpoint *mp, |
44d964d60 vfs: spread struc... |
788 |
struct mount *child_mnt) |
b90fa9ae8 [PATCH] shared mo... |
789 |
{ |
84d17192d get rid of full-h... |
790 |
mp->m_count++; |
3a2393d71 vfs: opencode mnt... |
791 |
mnt_add_count(mnt, 1); /* essentially, that's mntget */ |
4edbe133f make struct mount... |
792 |
child_mnt->mnt_mountpoint = mp->m_dentry; |
3a2393d71 vfs: opencode mnt... |
793 |
child_mnt->mnt_parent = mnt; |
84d17192d get rid of full-h... |
794 |
child_mnt->mnt_mp = mp; |
0a5eb7c81 vfs: Keep a list ... |
795 |
hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list); |
b90fa9ae8 [PATCH] shared mo... |
796 |
} |
1064f874a mnt: Tuck mounts ... |
797 798 799 800 801 802 |
static void __attach_mnt(struct mount *mnt, struct mount *parent) { hlist_add_head_rcu(&mnt->mnt_hash, m_hash(&parent->mnt, mnt->mnt_mountpoint)); list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); } |
99b7db7b8 fs: brlock vfsmou... |
803 804 805 |
/* * vfsmount lock must be held for write */ |
84d17192d get rid of full-h... |
806 807 808 |
static void attach_mnt(struct mount *mnt, struct mount *parent, struct mountpoint *mp) |
1da177e4c Linux-2.6.12-rc2 |
809 |
{ |
84d17192d get rid of full-h... |
810 |
mnt_set_mountpoint(parent, mp, mnt); |
1064f874a mnt: Tuck mounts ... |
811 |
__attach_mnt(mnt, parent); |
b90fa9ae8 [PATCH] shared mo... |
812 |
} |
1064f874a mnt: Tuck mounts ... |
813 |
void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *mnt) |
12a5b5294 fix copy_tree() r... |
814 |
{ |
1064f874a mnt: Tuck mounts ... |
815 |
struct mountpoint *old_mp = mnt->mnt_mp; |
1064f874a mnt: Tuck mounts ... |
816 817 818 819 820 821 822 823 824 |
struct mount *old_parent = mnt->mnt_parent; list_del_init(&mnt->mnt_child); hlist_del_init(&mnt->mnt_mp_list); hlist_del_init_rcu(&mnt->mnt_hash); attach_mnt(mnt, parent, mp); put_mountpoint(old_mp); |
1064f874a mnt: Tuck mounts ... |
825 |
mnt_add_count(old_parent, -1); |
12a5b5294 fix copy_tree() r... |
826 |
} |
b90fa9ae8 [PATCH] shared mo... |
827 |
/* |
99b7db7b8 fs: brlock vfsmou... |
828 |
* vfsmount lock must be held for write |
b90fa9ae8 [PATCH] shared mo... |
829 |
*/ |
1064f874a mnt: Tuck mounts ... |
830 |
static void commit_tree(struct mount *mnt) |
b90fa9ae8 [PATCH] shared mo... |
831 |
{ |
0714a5338 vfs: now it can b... |
832 |
struct mount *parent = mnt->mnt_parent; |
83adc7532 vfs: spread struc... |
833 |
struct mount *m; |
b90fa9ae8 [PATCH] shared mo... |
834 |
LIST_HEAD(head); |
143c8c91c vfs: mnt_ns moved... |
835 |
struct mnt_namespace *n = parent->mnt_ns; |
b90fa9ae8 [PATCH] shared mo... |
836 |
|
0714a5338 vfs: now it can b... |
837 |
BUG_ON(parent == mnt); |
b90fa9ae8 [PATCH] shared mo... |
838 |
|
1a4eeaf2a vfs: move mnt_lis... |
839 |
list_add_tail(&head, &mnt->mnt_list); |
f7a99c5b7 get rid of ->mnt_... |
840 |
list_for_each_entry(m, &head, mnt_list) |
143c8c91c vfs: mnt_ns moved... |
841 |
m->mnt_ns = n; |
f03c65993 sanitize vfsmount... |
842 |
|
b90fa9ae8 [PATCH] shared mo... |
843 |
list_splice(&head, n->list.prev); |
d29216842 mnt: Add a per mo... |
844 845 |
n->mounts += n->pending_mounts; n->pending_mounts = 0; |
1064f874a mnt: Tuck mounts ... |
846 |
__attach_mnt(mnt, parent); |
6b3286ed1 [PATCH] rename st... |
847 |
touch_mnt_namespace(n); |
1da177e4c Linux-2.6.12-rc2 |
848 |
} |
909b0a88e vfs: spread struc... |
849 |
static struct mount *next_mnt(struct mount *p, struct mount *root) |
1da177e4c Linux-2.6.12-rc2 |
850 |
{ |
6b41d536f vfs: take mnt_chi... |
851 852 |
struct list_head *next = p->mnt_mounts.next; if (next == &p->mnt_mounts) { |
1da177e4c Linux-2.6.12-rc2 |
853 |
while (1) { |
909b0a88e vfs: spread struc... |
854 |
if (p == root) |
1da177e4c Linux-2.6.12-rc2 |
855 |
return NULL; |
6b41d536f vfs: take mnt_chi... |
856 857 |
next = p->mnt_child.next; if (next != &p->mnt_parent->mnt_mounts) |
1da177e4c Linux-2.6.12-rc2 |
858 |
break; |
0714a5338 vfs: now it can b... |
859 |
p = p->mnt_parent; |
1da177e4c Linux-2.6.12-rc2 |
860 861 |
} } |
6b41d536f vfs: take mnt_chi... |
862 |
return list_entry(next, struct mount, mnt_child); |
1da177e4c Linux-2.6.12-rc2 |
863 |
} |
315fc83e5 vfs: spread struc... |
864 |
static struct mount *skip_mnt_tree(struct mount *p) |
9676f0c63 [PATCH] unbindabl... |
865 |
{ |
6b41d536f vfs: take mnt_chi... |
866 867 868 869 |
struct list_head *prev = p->mnt_mounts.prev; while (prev != &p->mnt_mounts) { p = list_entry(prev, struct mount, mnt_child); prev = p->mnt_mounts.prev; |
9676f0c63 [PATCH] unbindabl... |
870 871 872 |
} return p; } |
8f2918898 new helpers: vfs_... |
873 874 875 876 877 878 879 880 881 882 |
/** * vfs_create_mount - Create a mount for a configured superblock * @fc: The configuration context with the superblock attached * * Create a mount to an already configured superblock. If necessary, the * caller should invoke vfs_get_tree() before calling this. * * Note that this does not attach the mount to anything. */ struct vfsmount *vfs_create_mount(struct fs_context *fc) |
9d412a43c vfs: split off vf... |
883 |
{ |
b105e270b vfs: spread struc... |
884 |
struct mount *mnt; |
9d412a43c vfs: split off vf... |
885 |
|
8f2918898 new helpers: vfs_... |
886 887 |
if (!fc->root) return ERR_PTR(-EINVAL); |
9d412a43c vfs: split off vf... |
888 |
|
8f2918898 new helpers: vfs_... |
889 |
mnt = alloc_vfsmnt(fc->source ?: "none"); |
9d412a43c vfs: split off vf... |
890 891 |
if (!mnt) return ERR_PTR(-ENOMEM); |
8f2918898 new helpers: vfs_... |
892 |
if (fc->sb_flags & SB_KERNMOUNT) |
b105e270b vfs: spread struc... |
893 |
mnt->mnt.mnt_flags = MNT_INTERNAL; |
9d412a43c vfs: split off vf... |
894 |
|
8f2918898 new helpers: vfs_... |
895 896 897 898 899 |
atomic_inc(&fc->root->d_sb->s_active); mnt->mnt.mnt_sb = fc->root->d_sb; mnt->mnt.mnt_root = dget(fc->root); mnt->mnt_mountpoint = mnt->mnt.mnt_root; mnt->mnt_parent = mnt; |
9d412a43c vfs: split off vf... |
900 |
|
719ea2fbb new helpers: lock... |
901 |
lock_mount_hash(); |
8f2918898 new helpers: vfs_... |
902 |
list_add_tail(&mnt->mnt_instance, &mnt->mnt.mnt_sb->s_mounts); |
719ea2fbb new helpers: lock... |
903 |
unlock_mount_hash(); |
b105e270b vfs: spread struc... |
904 |
return &mnt->mnt; |
9d412a43c vfs: split off vf... |
905 |
} |
8f2918898 new helpers: vfs_... |
906 907 908 909 910 911 912 913 914 915 916 917 |
EXPORT_SYMBOL(vfs_create_mount); struct vfsmount *fc_mount(struct fs_context *fc) { int err = vfs_get_tree(fc); if (!err) { up_write(&fc->root->d_sb->s_umount); return vfs_create_mount(fc); } return ERR_PTR(err); } EXPORT_SYMBOL(fc_mount); |
9bc61ab18 vfs: Introduce fs... |
918 919 920 |
struct vfsmount *vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data) |
9d412a43c vfs: split off vf... |
921 |
{ |
9bc61ab18 vfs: Introduce fs... |
922 |
struct fs_context *fc; |
8f2918898 new helpers: vfs_... |
923 |
struct vfsmount *mnt; |
9bc61ab18 vfs: Introduce fs... |
924 |
int ret = 0; |
9d412a43c vfs: split off vf... |
925 926 |
if (!type) |
3e1aeb00e vfs: Implement a ... |
927 |
return ERR_PTR(-EINVAL); |
9d412a43c vfs: split off vf... |
928 |
|
9bc61ab18 vfs: Introduce fs... |
929 930 931 |
fc = fs_context_for_mount(type, flags); if (IS_ERR(fc)) return ERR_CAST(fc); |
3e1aeb00e vfs: Implement a ... |
932 933 934 |
if (name) ret = vfs_parse_fs_string(fc, "source", name, strlen(name)); |
9bc61ab18 vfs: Introduce fs... |
935 936 937 |
if (!ret) ret = parse_monolithic_mount_data(fc, data); if (!ret) |
8f2918898 new helpers: vfs_... |
938 939 940 |
mnt = fc_mount(fc); else mnt = ERR_PTR(ret); |
9d412a43c vfs: split off vf... |
941 |
|
9bc61ab18 vfs: Introduce fs... |
942 |
put_fs_context(fc); |
8f2918898 new helpers: vfs_... |
943 |
return mnt; |
9d412a43c vfs: split off vf... |
944 945 |
} EXPORT_SYMBOL_GPL(vfs_kern_mount); |
93faccbbf fs: Better permis... |
946 947 948 949 950 951 952 953 954 955 |
struct vfsmount * vfs_submount(const struct dentry *mountpoint, struct file_system_type *type, const char *name, void *data) { /* Until it is worked out how to pass the user namespace * through from the parent mount to the submount don't support * unprivileged mounts with submounts. */ if (mountpoint->d_sb->s_user_ns != &init_user_ns) return ERR_PTR(-EPERM); |
e462ec50c VFS: Differentiat... |
956 |
return vfs_kern_mount(type, SB_SUBMOUNT, name, data); |
93faccbbf fs: Better permis... |
957 958 |
} EXPORT_SYMBOL_GPL(vfs_submount); |
87129cc0e vfs: spread struc... |
959 |
static struct mount *clone_mnt(struct mount *old, struct dentry *root, |
36341f645 [PATCH] mount exp... |
960 |
int flag) |
1da177e4c Linux-2.6.12-rc2 |
961 |
{ |
87129cc0e vfs: spread struc... |
962 |
struct super_block *sb = old->mnt.mnt_sb; |
be34d1a3b VFS: Make clone_m... |
963 964 |
struct mount *mnt; int err; |
1da177e4c Linux-2.6.12-rc2 |
965 |
|
be34d1a3b VFS: Make clone_m... |
966 967 968 |
mnt = alloc_vfsmnt(old->mnt_devname); if (!mnt) return ERR_PTR(-ENOMEM); |
719f5d7f0 [patch 4/7] vfs: ... |
969 |
|
7a472ef4b vfs: Only support... |
970 |
if (flag & (CL_SLAVE | CL_PRIVATE | CL_SHARED_TO_SLAVE)) |
be34d1a3b VFS: Make clone_m... |
971 972 973 |
mnt->mnt_group_id = 0; /* not a peer of original */ else mnt->mnt_group_id = old->mnt_group_id; |
b90fa9ae8 [PATCH] shared mo... |
974 |
|
be34d1a3b VFS: Make clone_m... |
975 976 977 978 |
if ((flag & CL_MAKE_SHARED) && !mnt->mnt_group_id) { err = mnt_alloc_group_id(mnt); if (err) goto out_free; |
1da177e4c Linux-2.6.12-rc2 |
979 |
} |
be34d1a3b VFS: Make clone_m... |
980 |
|
16a34adb9 Don't leak MNT_IN... |
981 982 |
mnt->mnt.mnt_flags = old->mnt.mnt_flags; mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL); |
5ff9d8a65 vfs: Lock in plac... |
983 |
|
be34d1a3b VFS: Make clone_m... |
984 985 986 987 988 |
atomic_inc(&sb->s_active); mnt->mnt.mnt_sb = sb; mnt->mnt.mnt_root = dget(root); mnt->mnt_mountpoint = mnt->mnt.mnt_root; mnt->mnt_parent = mnt; |
719ea2fbb new helpers: lock... |
989 |
lock_mount_hash(); |
be34d1a3b VFS: Make clone_m... |
990 |
list_add_tail(&mnt->mnt_instance, &sb->s_mounts); |
719ea2fbb new helpers: lock... |
991 |
unlock_mount_hash(); |
be34d1a3b VFS: Make clone_m... |
992 |
|
7a472ef4b vfs: Only support... |
993 994 |
if ((flag & CL_SLAVE) || ((flag & CL_SHARED_TO_SLAVE) && IS_MNT_SHARED(old))) { |
be34d1a3b VFS: Make clone_m... |
995 996 997 998 999 1000 1001 1002 1003 |
list_add(&mnt->mnt_slave, &old->mnt_slave_list); mnt->mnt_master = old; CLEAR_MNT_SHARED(mnt); } else if (!(flag & CL_PRIVATE)) { if ((flag & CL_MAKE_SHARED) || IS_MNT_SHARED(old)) list_add(&mnt->mnt_share, &old->mnt_share); if (IS_MNT_SLAVE(old)) list_add(&mnt->mnt_slave, &old->mnt_slave); mnt->mnt_master = old->mnt_master; |
5235d448c reorganize do_mak... |
1004 1005 |
} else { CLEAR_MNT_SHARED(mnt); |
be34d1a3b VFS: Make clone_m... |
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 |
} if (flag & CL_MAKE_SHARED) set_mnt_shared(mnt); /* stick the duplicate mount on the same expiry list * as the original if that was on one */ if (flag & CL_EXPIRE) { if (!list_empty(&old->mnt_expire)) list_add(&mnt->mnt_expire, &old->mnt_expire); } |
cb338d06e vfs: spread struc... |
1016 |
return mnt; |
719f5d7f0 [patch 4/7] vfs: ... |
1017 1018 |
out_free: |
8ffcb32e0 VFS: Make delayed... |
1019 |
mnt_free_id(mnt); |
719f5d7f0 [patch 4/7] vfs: ... |
1020 |
free_vfsmnt(mnt); |
be34d1a3b VFS: Make clone_m... |
1021 |
return ERR_PTR(err); |
1da177e4c Linux-2.6.12-rc2 |
1022 |
} |
9ea459e11 delayed mntput |
1023 1024 |
static void cleanup_mnt(struct mount *mnt) { |
56cbb429d switch the remnan... |
1025 1026 |
struct hlist_node *p; struct mount *m; |
9ea459e11 delayed mntput |
1027 |
/* |
56cbb429d switch the remnan... |
1028 1029 1030 |
* The warning here probably indicates that somebody messed * up a mnt_want/drop_write() pair. If this happens, the * filesystem was probably unable to make r/w->r/o transitions. |
9ea459e11 delayed mntput |
1031 1032 1033 1034 1035 1036 |
* The locking used to deal with mnt_count decrement provides barriers, * so mnt_get_writers() below is safe. */ WARN_ON(mnt_get_writers(mnt)); if (unlikely(mnt->mnt_pins.first)) mnt_pin_kill(mnt); |
56cbb429d switch the remnan... |
1037 1038 1039 1040 |
hlist_for_each_entry_safe(m, p, &mnt->mnt_stuck_children, mnt_umount) { hlist_del(&m->mnt_umount); mntput(&m->mnt); } |
9ea459e11 delayed mntput |
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 |
fsnotify_vfsmount_delete(&mnt->mnt); dput(mnt->mnt.mnt_root); deactivate_super(mnt->mnt.mnt_sb); mnt_free_id(mnt); call_rcu(&mnt->mnt_rcu, delayed_free_vfsmnt); } static void __cleanup_mnt(struct rcu_head *head) { cleanup_mnt(container_of(head, struct mount, mnt_rcu)); } static LLIST_HEAD(delayed_mntput_list); static void delayed_mntput(struct work_struct *unused) { struct llist_node *node = llist_del_all(&delayed_mntput_list); |
297857357 namespace.c: Don'... |
1057 |
struct mount *m, *t; |
9ea459e11 delayed mntput |
1058 |
|
297857357 namespace.c: Don'... |
1059 1060 |
llist_for_each_entry_safe(m, t, node, mnt_llist) cleanup_mnt(m); |
9ea459e11 delayed mntput |
1061 1062 |
} static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput); |
900148dca vfs: spread struc... |
1063 |
static void mntput_no_expire(struct mount *mnt) |
b3e19d924 fs: scale mntget/... |
1064 |
{ |
4edbe133f make struct mount... |
1065 |
LIST_HEAD(list); |
48a066e72 RCU'd vfsmounts |
1066 |
rcu_read_lock(); |
9ea0a46ca fix mntput/mntput... |
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 |
if (likely(READ_ONCE(mnt->mnt_ns))) { /* * Since we don't do lock_mount_hash() here, * ->mnt_ns can change under us. However, if it's * non-NULL, then there's a reference that won't * be dropped until after an RCU delay done after * turning ->mnt_ns NULL. So if we observe it * non-NULL under rcu_read_lock(), the reference * we are dropping is not the final one. */ mnt_add_count(mnt, -1); |
48a066e72 RCU'd vfsmounts |
1078 |
rcu_read_unlock(); |
f03c65993 sanitize vfsmount... |
1079 |
return; |
b3e19d924 fs: scale mntget/... |
1080 |
} |
719ea2fbb new helpers: lock... |
1081 |
lock_mount_hash(); |
119e1ef80 fix __legitimize_... |
1082 1083 1084 1085 1086 |
/* * make sure that if __legitimize_mnt() has not seen us grab * mount_lock, we'll see their refcount increment here. */ smp_mb(); |
9ea0a46ca fix mntput/mntput... |
1087 |
mnt_add_count(mnt, -1); |
b3e19d924 fs: scale mntget/... |
1088 |
if (mnt_get_count(mnt)) { |
48a066e72 RCU'd vfsmounts |
1089 |
rcu_read_unlock(); |
719ea2fbb new helpers: lock... |
1090 |
unlock_mount_hash(); |
99b7db7b8 fs: brlock vfsmou... |
1091 1092 |
return; } |
48a066e72 RCU'd vfsmounts |
1093 1094 1095 1096 1097 1098 1099 |
if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) { rcu_read_unlock(); unlock_mount_hash(); return; } mnt->mnt.mnt_flags |= MNT_DOOMED; rcu_read_unlock(); |
962830df3 brlocks/lglocks: ... |
1100 |
|
39f7c4db1 vfs: keep list of... |
1101 |
list_del(&mnt->mnt_instance); |
ce07d891a mnt: Honor MNT_LO... |
1102 1103 1104 1105 |
if (unlikely(!list_empty(&mnt->mnt_mounts))) { struct mount *p, *tmp; list_for_each_entry_safe(p, tmp, &mnt->mnt_mounts, mnt_child) { |
4edbe133f make struct mount... |
1106 |
__put_mountpoint(unhash_mnt(p), &list); |
56cbb429d switch the remnan... |
1107 |
hlist_add_head(&p->mnt_umount, &mnt->mnt_stuck_children); |
ce07d891a mnt: Honor MNT_LO... |
1108 1109 |
} } |
719ea2fbb new helpers: lock... |
1110 |
unlock_mount_hash(); |
4edbe133f make struct mount... |
1111 |
shrink_dentry_list(&list); |
649a795af fold mntfree() in... |
1112 |
|
9ea459e11 delayed mntput |
1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 |
if (likely(!(mnt->mnt.mnt_flags & MNT_INTERNAL))) { struct task_struct *task = current; if (likely(!(task->flags & PF_KTHREAD))) { init_task_work(&mnt->mnt_rcu, __cleanup_mnt); if (!task_work_add(task, &mnt->mnt_rcu, true)) return; } if (llist_add(&mnt->mnt_llist, &delayed_mntput_list)) schedule_delayed_work(&delayed_mntput_work, 1); return; } cleanup_mnt(mnt); |
b3e19d924 fs: scale mntget/... |
1125 |
} |
b3e19d924 fs: scale mntget/... |
1126 1127 1128 1129 |
void mntput(struct vfsmount *mnt) { if (mnt) { |
863d684f9 vfs: move the res... |
1130 |
struct mount *m = real_mount(mnt); |
b3e19d924 fs: scale mntget/... |
1131 |
/* avoid cacheline pingpong, hope gcc doesn't get "smart" */ |
863d684f9 vfs: move the res... |
1132 1133 1134 |
if (unlikely(m->mnt_expiry_mark)) m->mnt_expiry_mark = 0; mntput_no_expire(m); |
b3e19d924 fs: scale mntget/... |
1135 1136 1137 1138 1139 1140 1141 |
} } EXPORT_SYMBOL(mntput); struct vfsmount *mntget(struct vfsmount *mnt) { if (mnt) |
83adc7532 vfs: spread struc... |
1142 |
mnt_add_count(real_mount(mnt), 1); |
b3e19d924 fs: scale mntget/... |
1143 1144 1145 |
return mnt; } EXPORT_SYMBOL(mntget); |
c6609c0a1 vfs: add path_is_... |
1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 |
/* path_is_mountpoint() - Check if path is a mount in the current * namespace. * * d_mountpoint() can only be used reliably to establish if a dentry is * not mounted in any namespace and that common case is handled inline. * d_mountpoint() isn't aware of the possibility there may be multiple * mounts using a given dentry in a different namespace. This function * checks if the passed in path is a mountpoint rather than the dentry * alone. */ bool path_is_mountpoint(const struct path *path) { unsigned seq; bool res; if (!d_mountpoint(path->dentry)) return false; rcu_read_lock(); do { seq = read_seqbegin(&mount_lock); res = __path_is_mountpoint(path); } while (read_seqretry(&mount_lock, seq)); rcu_read_unlock(); return res; } EXPORT_SYMBOL(path_is_mountpoint); |
ca71cf71e namespace.c: cons... |
1174 |
struct vfsmount *mnt_clone_internal(const struct path *path) |
7b7b1ace2 [PATCH] saner han... |
1175 |
{ |
3064c3563 death to mnt_pinned |
1176 1177 1178 1179 1180 1181 |
struct mount *p; p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE); if (IS_ERR(p)) return ERR_CAST(p); p->mnt.mnt_flags |= MNT_INTERNAL; return &p->mnt; |
7b7b1ace2 [PATCH] saner han... |
1182 |
} |
1da177e4c Linux-2.6.12-rc2 |
1183 |
|
a1a2c409b [patch 5/7] vfs: ... |
1184 |
#ifdef CONFIG_PROC_FS |
0226f4923 vfs: take /proc/*... |
1185 |
/* iterator; we want it to have access to namespace_sem, thus here... */ |
1da177e4c Linux-2.6.12-rc2 |
1186 1187 |
static void *m_start(struct seq_file *m, loff_t *pos) { |
ede1bf0dc fs: use seq_open_... |
1188 |
struct proc_mounts *p = m->private; |
1da177e4c Linux-2.6.12-rc2 |
1189 |
|
390c68436 [PATCH] making na... |
1190 |
down_read(&namespace_sem); |
c7999c362 reduce m_start() ... |
1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 |
if (p->cached_event == p->ns->event) { void *v = p->cached_mount; if (*pos == p->cached_index) return v; if (*pos == p->cached_index + 1) { v = seq_list_next(v, &p->ns->list, &p->cached_index); return p->cached_mount = v; } } p->cached_event = p->ns->event; p->cached_mount = seq_list_start(&p->ns->list, *pos); p->cached_index = *pos; return p->cached_mount; |
1da177e4c Linux-2.6.12-rc2 |
1205 1206 1207 1208 |
} static void *m_next(struct seq_file *m, void *v, loff_t *pos) { |
ede1bf0dc fs: use seq_open_... |
1209 |
struct proc_mounts *p = m->private; |
b0765fb85 Make /proc/self/m... |
1210 |
|
c7999c362 reduce m_start() ... |
1211 1212 1213 |
p->cached_mount = seq_list_next(v, &p->ns->list, pos); p->cached_index = *pos; return p->cached_mount; |
1da177e4c Linux-2.6.12-rc2 |
1214 1215 1216 1217 |
} static void m_stop(struct seq_file *m, void *v) { |
390c68436 [PATCH] making na... |
1218 |
up_read(&namespace_sem); |
1da177e4c Linux-2.6.12-rc2 |
1219 |
} |
0226f4923 vfs: take /proc/*... |
1220 |
static int m_show(struct seq_file *m, void *v) |
2d4d4864a [patch 6/7] vfs: ... |
1221 |
{ |
ede1bf0dc fs: use seq_open_... |
1222 |
struct proc_mounts *p = m->private; |
1a4eeaf2a vfs: move mnt_lis... |
1223 |
struct mount *r = list_entry(v, struct mount, mnt_list); |
0226f4923 vfs: take /proc/*... |
1224 |
return p->show(m, &r->mnt); |
1da177e4c Linux-2.6.12-rc2 |
1225 |
} |
a1a2c409b [patch 5/7] vfs: ... |
1226 |
const struct seq_operations mounts_op = { |
1da177e4c Linux-2.6.12-rc2 |
1227 1228 1229 |
.start = m_start, .next = m_next, .stop = m_stop, |
0226f4923 vfs: take /proc/*... |
1230 |
.show = m_show, |
b4629fe2f VFS: New /proc fi... |
1231 |
}; |
a1a2c409b [patch 5/7] vfs: ... |
1232 |
#endif /* CONFIG_PROC_FS */ |
b4629fe2f VFS: New /proc fi... |
1233 |
|
1da177e4c Linux-2.6.12-rc2 |
1234 1235 1236 1237 1238 1239 1240 1241 |
/** * may_umount_tree - check if a mount tree is busy * @mnt: root of mount tree * * This is called to check if a tree of mounts has any * open files, pwds, chroots or sub mounts that are * busy. */ |
909b0a88e vfs: spread struc... |
1242 |
int may_umount_tree(struct vfsmount *m) |
1da177e4c Linux-2.6.12-rc2 |
1243 |
{ |
909b0a88e vfs: spread struc... |
1244 |
struct mount *mnt = real_mount(m); |
36341f645 [PATCH] mount exp... |
1245 1246 |
int actual_refs = 0; int minimum_refs = 0; |
315fc83e5 vfs: spread struc... |
1247 |
struct mount *p; |
909b0a88e vfs: spread struc... |
1248 |
BUG_ON(!m); |
1da177e4c Linux-2.6.12-rc2 |
1249 |
|
b3e19d924 fs: scale mntget/... |
1250 |
/* write lock needed for mnt_get_count */ |
719ea2fbb new helpers: lock... |
1251 |
lock_mount_hash(); |
909b0a88e vfs: spread struc... |
1252 |
for (p = mnt; p; p = next_mnt(p, mnt)) { |
83adc7532 vfs: spread struc... |
1253 |
actual_refs += mnt_get_count(p); |
1da177e4c Linux-2.6.12-rc2 |
1254 |
minimum_refs += 2; |
1da177e4c Linux-2.6.12-rc2 |
1255 |
} |
719ea2fbb new helpers: lock... |
1256 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1257 1258 |
if (actual_refs > minimum_refs) |
e3474a8eb [PATCH] autofs4: ... |
1259 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1260 |
|
e3474a8eb [PATCH] autofs4: ... |
1261 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 |
} EXPORT_SYMBOL(may_umount_tree); /** * may_umount - check if a mount point is busy * @mnt: root of mount * * This is called to check if a mount point has any * open files, pwds, chroots or sub mounts. If the * mount has sub mounts this will return busy * regardless of whether the sub mounts are busy. * * Doesn't take quota and stuff into account. IOW, in some cases it will * give false negatives. The main reason why it's here is that we need * a non-destructive way to look for easily umountable filesystems. */ int may_umount(struct vfsmount *mnt) { |
e3474a8eb [PATCH] autofs4: ... |
1281 |
int ret = 1; |
8ad08d8a0 may_umount() need... |
1282 |
down_read(&namespace_sem); |
719ea2fbb new helpers: lock... |
1283 |
lock_mount_hash(); |
1ab597386 vfs: spread struc... |
1284 |
if (propagate_mount_busy(real_mount(mnt), 2)) |
e3474a8eb [PATCH] autofs4: ... |
1285 |
ret = 0; |
719ea2fbb new helpers: lock... |
1286 |
unlock_mount_hash(); |
8ad08d8a0 may_umount() need... |
1287 |
up_read(&namespace_sem); |
a05964f39 [PATCH] shared mo... |
1288 |
return ret; |
1da177e4c Linux-2.6.12-rc2 |
1289 1290 1291 |
} EXPORT_SYMBOL(may_umount); |
97216be09 fold release_moun... |
1292 |
static void namespace_unlock(void) |
70fbcdf4d [PATCH] umount_tr... |
1293 |
{ |
a3b3c5627 mnt: Use hlist_mo... |
1294 |
struct hlist_head head; |
56cbb429d switch the remnan... |
1295 1296 |
struct hlist_node *p; struct mount *m; |
4edbe133f make struct mount... |
1297 |
LIST_HEAD(list); |
97216be09 fold release_moun... |
1298 |
|
a3b3c5627 mnt: Use hlist_mo... |
1299 |
hlist_move_list(&unmounted, &head); |
4edbe133f make struct mount... |
1300 |
list_splice_init(&ex_mountpoints, &list); |
97216be09 fold release_moun... |
1301 |
|
97216be09 fold release_moun... |
1302 |
up_write(&namespace_sem); |
4edbe133f make struct mount... |
1303 |
shrink_dentry_list(&list); |
a3b3c5627 mnt: Use hlist_mo... |
1304 1305 |
if (likely(hlist_empty(&head))) return; |
22cb7405f VFS: use synchron... |
1306 |
synchronize_rcu_expedited(); |
48a066e72 RCU'd vfsmounts |
1307 |
|
56cbb429d switch the remnan... |
1308 1309 1310 1311 |
hlist_for_each_entry_safe(m, p, &head, mnt_umount) { hlist_del(&m->mnt_umount); mntput(&m->mnt); } |
70fbcdf4d [PATCH] umount_tr... |
1312 |
} |
97216be09 fold release_moun... |
1313 |
static inline void namespace_lock(void) |
e3197d83d saner umount_tree... |
1314 |
{ |
97216be09 fold release_moun... |
1315 |
down_write(&namespace_sem); |
e3197d83d saner umount_tree... |
1316 |
} |
e819f1521 mnt: Improve the ... |
1317 1318 1319 |
enum umount_tree_flags { UMOUNT_SYNC = 1, UMOUNT_PROPAGATE = 2, |
e0c9c0afd mnt: Update detac... |
1320 |
UMOUNT_CONNECTED = 4, |
e819f1521 mnt: Improve the ... |
1321 |
}; |
f2d0a123b mnt: Clarify and ... |
1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 |
static bool disconnect_mount(struct mount *mnt, enum umount_tree_flags how) { /* Leaving mounts connected is only valid for lazy umounts */ if (how & UMOUNT_SYNC) return true; /* A mount without a parent has nothing to be connected to */ if (!mnt_has_parent(mnt)) return true; /* Because the reference counting rules change when mounts are * unmounted and connected, umounted mounts may not be * connected to mounted mounts. */ if (!(mnt->mnt_parent->mnt.mnt_flags & MNT_UMOUNT)) return true; /* Has it been requested that the mount remain connected? */ if (how & UMOUNT_CONNECTED) return false; /* Is the mount locked such that it needs to remain connected? */ if (IS_MNT_LOCKED(mnt)) return false; /* By default disconnect the mount */ return true; } |
99b7db7b8 fs: brlock vfsmou... |
1351 |
/* |
48a066e72 RCU'd vfsmounts |
1352 |
* mount_lock must be held |
99b7db7b8 fs: brlock vfsmou... |
1353 1354 |
* namespace_sem must be held for write */ |
e819f1521 mnt: Improve the ... |
1355 |
static void umount_tree(struct mount *mnt, enum umount_tree_flags how) |
1da177e4c Linux-2.6.12-rc2 |
1356 |
{ |
c003b26ff mnt: In umount_tr... |
1357 |
LIST_HEAD(tmp_list); |
315fc83e5 vfs: spread struc... |
1358 |
struct mount *p; |
1da177e4c Linux-2.6.12-rc2 |
1359 |
|
5d88457eb mnt: On an unmoun... |
1360 1361 |
if (how & UMOUNT_PROPAGATE) propagate_mount_unlock(mnt); |
c003b26ff mnt: In umount_tr... |
1362 |
/* Gather the mounts to umount */ |
590ce4bcb mnt: Add MNT_UMOU... |
1363 1364 |
for (p = mnt; p; p = next_mnt(p, mnt)) { p->mnt.mnt_flags |= MNT_UMOUNT; |
c003b26ff mnt: In umount_tr... |
1365 |
list_move(&p->mnt_list, &tmp_list); |
590ce4bcb mnt: Add MNT_UMOU... |
1366 |
} |
1da177e4c Linux-2.6.12-rc2 |
1367 |
|
411a938b5 mnt: Delay remova... |
1368 |
/* Hide the mounts from mnt_mounts */ |
c003b26ff mnt: In umount_tr... |
1369 |
list_for_each_entry(p, &tmp_list, mnt_list) { |
88b368f27 get rid of propag... |
1370 |
list_del_init(&p->mnt_child); |
c003b26ff mnt: In umount_tr... |
1371 |
} |
88b368f27 get rid of propag... |
1372 |
|
c003b26ff mnt: In umount_tr... |
1373 |
/* Add propogated mounts to the tmp_list */ |
e819f1521 mnt: Improve the ... |
1374 |
if (how & UMOUNT_PROPAGATE) |
7b8a53fd8 fix old umount_tr... |
1375 |
propagate_umount(&tmp_list); |
a05964f39 [PATCH] shared mo... |
1376 |
|
c003b26ff mnt: In umount_tr... |
1377 |
while (!list_empty(&tmp_list)) { |
d29216842 mnt: Add a per mo... |
1378 |
struct mnt_namespace *ns; |
ce07d891a mnt: Honor MNT_LO... |
1379 |
bool disconnect; |
c003b26ff mnt: In umount_tr... |
1380 |
p = list_first_entry(&tmp_list, struct mount, mnt_list); |
6776db3d3 vfs: take mnt_sha... |
1381 |
list_del_init(&p->mnt_expire); |
1a4eeaf2a vfs: move mnt_lis... |
1382 |
list_del_init(&p->mnt_list); |
d29216842 mnt: Add a per mo... |
1383 1384 1385 1386 1387 |
ns = p->mnt_ns; if (ns) { ns->mounts--; __touch_mnt_namespace(ns); } |
143c8c91c vfs: mnt_ns moved... |
1388 |
p->mnt_ns = NULL; |
e819f1521 mnt: Improve the ... |
1389 |
if (how & UMOUNT_SYNC) |
48a066e72 RCU'd vfsmounts |
1390 |
p->mnt.mnt_flags |= MNT_SYNC_UMOUNT; |
87b95ce09 switch the IO-tri... |
1391 |
|
f2d0a123b mnt: Clarify and ... |
1392 |
disconnect = disconnect_mount(p, how); |
676da58df vfs: spread struc... |
1393 |
if (mnt_has_parent(p)) { |
81b6b0619 fix EBUSY on umou... |
1394 |
mnt_add_count(p->mnt_parent, -1); |
ce07d891a mnt: Honor MNT_LO... |
1395 1396 1397 1398 1399 1400 |
if (!disconnect) { /* Don't forget about p */ list_add_tail(&p->mnt_child, &p->mnt_parent->mnt_mounts); } else { umount_mnt(p); } |
7c4b93d82 [PATCH] count gho... |
1401 |
} |
0f0afb1dc vfs: spread struc... |
1402 |
change_mnt_propagation(p, MS_PRIVATE); |
19a1c4092 fix the struct mo... |
1403 1404 |
if (disconnect) hlist_add_head(&p->mnt_umount, &unmounted); |
1da177e4c Linux-2.6.12-rc2 |
1405 1406 |
} } |
b54b9be78 get rid of the se... |
1407 |
static void shrink_submounts(struct mount *mnt); |
c35038bec [PATCH] do shrink... |
1408 |
|
8d0347f6c convert do_remoun... |
1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 |
static int do_umount_root(struct super_block *sb) { int ret = 0; down_write(&sb->s_umount); if (!sb_rdonly(sb)) { struct fs_context *fc; fc = fs_context_for_reconfigure(sb->s_root, SB_RDONLY, SB_RDONLY); if (IS_ERR(fc)) { ret = PTR_ERR(fc); } else { ret = parse_monolithic_mount_data(fc, NULL); if (!ret) ret = reconfigure_super(fc); put_fs_context(fc); } } up_write(&sb->s_umount); return ret; } |
1ab597386 vfs: spread struc... |
1431 |
static int do_umount(struct mount *mnt, int flags) |
1da177e4c Linux-2.6.12-rc2 |
1432 |
{ |
1ab597386 vfs: spread struc... |
1433 |
struct super_block *sb = mnt->mnt.mnt_sb; |
1da177e4c Linux-2.6.12-rc2 |
1434 |
int retval; |
1ab597386 vfs: spread struc... |
1435 |
retval = security_sb_umount(&mnt->mnt, flags); |
1da177e4c Linux-2.6.12-rc2 |
1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 |
if (retval) return retval; /* * Allow userspace to request a mountpoint be expired rather than * unmounting unconditionally. Unmount only happens if: * (1) the mark is already set (the mark is cleared by mntput()) * (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount] */ if (flags & MNT_EXPIRE) { |
1ab597386 vfs: spread struc... |
1446 |
if (&mnt->mnt == current->fs->root.mnt || |
1da177e4c Linux-2.6.12-rc2 |
1447 1448 |
flags & (MNT_FORCE | MNT_DETACH)) return -EINVAL; |
b3e19d924 fs: scale mntget/... |
1449 1450 1451 1452 |
/* * probably don't strictly need the lock here if we examined * all race cases, but it's a slowpath. */ |
719ea2fbb new helpers: lock... |
1453 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
1454 |
if (mnt_get_count(mnt) != 2) { |
719ea2fbb new helpers: lock... |
1455 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1456 |
return -EBUSY; |
b3e19d924 fs: scale mntget/... |
1457 |
} |
719ea2fbb new helpers: lock... |
1458 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1459 |
|
863d684f9 vfs: move the res... |
1460 |
if (!xchg(&mnt->mnt_expiry_mark, 1)) |
1da177e4c Linux-2.6.12-rc2 |
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 |
return -EAGAIN; } /* * If we may have to abort operations to get out of this * mount, and they will themselves hold resources we must * allow the fs to do things. In the Unix tradition of * 'Gee thats tricky lets do it in userspace' the umount_begin * might fail to complete on the first run through as other tasks * must return, and the like. Thats for the mount program to worry * about for the moment. */ |
42faad996 [PATCH] restore s... |
1473 |
if (flags & MNT_FORCE && sb->s_op->umount_begin) { |
42faad996 [PATCH] restore s... |
1474 |
sb->s_op->umount_begin(sb); |
42faad996 [PATCH] restore s... |
1475 |
} |
1da177e4c Linux-2.6.12-rc2 |
1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 |
/* * No sense to grab the lock for this test, but test itself looks * somewhat bogus. Suggestions for better replacement? * Ho-hum... In principle, we might treat that as umount + switch * to rootfs. GC would eventually take care of the old vfsmount. * Actually it makes sense, especially if rootfs would contain a * /reboot - static binary that would close all descriptors and * call reboot(9). Then init(8) could umount root and exec /reboot. */ |
1ab597386 vfs: spread struc... |
1486 |
if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) { |
1da177e4c Linux-2.6.12-rc2 |
1487 1488 1489 1490 |
/* * Special case for "unmounting" root ... * we just try to remount it readonly. */ |
bc6155d13 fs: Allow superbl... |
1491 |
if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) |
a1480dcc3 fs: Add a missing... |
1492 |
return -EPERM; |
8d0347f6c convert do_remoun... |
1493 |
return do_umount_root(sb); |
1da177e4c Linux-2.6.12-rc2 |
1494 |
} |
97216be09 fold release_moun... |
1495 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
1496 |
lock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1497 |
|
25d202ed8 mount: Retest MNT... |
1498 1499 1500 1501 1502 1503 |
/* Recheck MNT_LOCKED with the locks held */ retval = -EINVAL; if (mnt->mnt.mnt_flags & MNT_LOCKED) goto out; event++; |
48a066e72 RCU'd vfsmounts |
1504 |
if (flags & MNT_DETACH) { |
1a4eeaf2a vfs: move mnt_lis... |
1505 |
if (!list_empty(&mnt->mnt_list)) |
e819f1521 mnt: Improve the ... |
1506 |
umount_tree(mnt, UMOUNT_PROPAGATE); |
1da177e4c Linux-2.6.12-rc2 |
1507 |
retval = 0; |
48a066e72 RCU'd vfsmounts |
1508 1509 1510 1511 1512 |
} else { shrink_submounts(mnt); retval = -EBUSY; if (!propagate_mount_busy(mnt, 2)) { if (!list_empty(&mnt->mnt_list)) |
e819f1521 mnt: Improve the ... |
1513 |
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
48a066e72 RCU'd vfsmounts |
1514 1515 |
retval = 0; } |
1da177e4c Linux-2.6.12-rc2 |
1516 |
} |
25d202ed8 mount: Retest MNT... |
1517 |
out: |
719ea2fbb new helpers: lock... |
1518 |
unlock_mount_hash(); |
e3197d83d saner umount_tree... |
1519 |
namespace_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1520 1521 |
return retval; } |
80b5dce8c vfs: Add a functi... |
1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 |
/* * __detach_mounts - lazily unmount all mounts on the specified dentry * * During unlink, rmdir, and d_drop it is possible to loose the path * to an existing mountpoint, and wind up leaking the mount. * detach_mounts allows lazily unmounting those mounts instead of * leaking them. * * The caller may hold dentry->d_inode->i_mutex. */ void __detach_mounts(struct dentry *dentry) { struct mountpoint *mp; struct mount *mnt; namespace_lock(); |
3895dbf89 mnt: Protect the ... |
1538 |
lock_mount_hash(); |
80b5dce8c vfs: Add a functi... |
1539 |
mp = lookup_mountpoint(dentry); |
adc9b5c09 __detach_mounts()... |
1540 |
if (!mp) |
80b5dce8c vfs: Add a functi... |
1541 |
goto out_unlock; |
e06b933e6 namespace: update... |
1542 |
event++; |
80b5dce8c vfs: Add a functi... |
1543 1544 |
while (!hlist_empty(&mp->m_list)) { mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list); |
ce07d891a mnt: Honor MNT_LO... |
1545 |
if (mnt->mnt.mnt_flags & MNT_UMOUNT) { |
fe78fcc85 mnt: In detach_mo... |
1546 |
umount_mnt(mnt); |
56cbb429d switch the remnan... |
1547 |
hlist_add_head(&mnt->mnt_umount, &unmounted); |
ce07d891a mnt: Honor MNT_LO... |
1548 |
} |
e0c9c0afd mnt: Update detac... |
1549 |
else umount_tree(mnt, UMOUNT_CONNECTED); |
80b5dce8c vfs: Add a functi... |
1550 |
} |
80b5dce8c vfs: Add a functi... |
1551 1552 |
put_mountpoint(mp); out_unlock: |
3895dbf89 mnt: Protect the ... |
1553 |
unlock_mount_hash(); |
80b5dce8c vfs: Add a functi... |
1554 1555 |
namespace_unlock(); } |
dd111b31e VFS: Clean up whi... |
1556 |
/* |
9b40bc90a get rid of unprot... |
1557 1558 1559 1560 1561 1562 |
* Is the caller allowed to modify his namespace? */ static inline bool may_mount(void) { return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN); } |
df2474a22 locks: print a wa... |
1563 |
#ifdef CONFIG_MANDATORY_FILE_LOCKING |
9e8925b67 locks: Allow disa... |
1564 1565 |
static inline bool may_mandlock(void) { |
95ace7541 locks: Don't allo... |
1566 |
return capable(CAP_SYS_ADMIN); |
9e8925b67 locks: Allow disa... |
1567 |
} |
df2474a22 locks: print a wa... |
1568 1569 1570 1571 1572 1573 1574 |
#else static inline bool may_mandlock(void) { pr_warn("VFS: \"mand\" mount option not supported"); return false; } #endif |
9e8925b67 locks: Allow disa... |
1575 |
|
1da177e4c Linux-2.6.12-rc2 |
1576 1577 1578 1579 1580 1581 1582 |
/* * Now umount can handle mount points as well as block devices. * This is important for filesystems which use unnamed block devices. * * We now support a flag for forced unmount like the other 'big iron' * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD */ |
3a18ef5c1 fs: add ksys_umou... |
1583 |
int ksys_umount(char __user *name, int flags) |
1da177e4c Linux-2.6.12-rc2 |
1584 |
{ |
2d8f30380 [PATCH] sanitize ... |
1585 |
struct path path; |
900148dca vfs: spread struc... |
1586 |
struct mount *mnt; |
1da177e4c Linux-2.6.12-rc2 |
1587 |
int retval; |
db1f05bb8 vfs: add NOFOLLOW... |
1588 |
int lookup_flags = 0; |
1da177e4c Linux-2.6.12-rc2 |
1589 |
|
db1f05bb8 vfs: add NOFOLLOW... |
1590 1591 |
if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW)) return -EINVAL; |
9b40bc90a get rid of unprot... |
1592 1593 |
if (!may_mount()) return -EPERM; |
db1f05bb8 vfs: add NOFOLLOW... |
1594 1595 |
if (!(flags & UMOUNT_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; |
197df04c7 rename user_path_... |
1596 |
retval = user_path_mountpoint_at(AT_FDCWD, name, lookup_flags, &path); |
1da177e4c Linux-2.6.12-rc2 |
1597 1598 |
if (retval) goto out; |
900148dca vfs: spread struc... |
1599 |
mnt = real_mount(path.mnt); |
1da177e4c Linux-2.6.12-rc2 |
1600 |
retval = -EINVAL; |
2d8f30380 [PATCH] sanitize ... |
1601 |
if (path.dentry != path.mnt->mnt_root) |
1da177e4c Linux-2.6.12-rc2 |
1602 |
goto dput_and_out; |
143c8c91c vfs: mnt_ns moved... |
1603 |
if (!check_mnt(mnt)) |
1da177e4c Linux-2.6.12-rc2 |
1604 |
goto dput_and_out; |
25d202ed8 mount: Retest MNT... |
1605 |
if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */ |
5ff9d8a65 vfs: Lock in plac... |
1606 |
goto dput_and_out; |
b2f5d4dc3 umount: Disallow ... |
1607 1608 1609 |
retval = -EPERM; if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN)) goto dput_and_out; |
1da177e4c Linux-2.6.12-rc2 |
1610 |
|
900148dca vfs: spread struc... |
1611 |
retval = do_umount(mnt, flags); |
1da177e4c Linux-2.6.12-rc2 |
1612 |
dput_and_out: |
429731b15 Remove path_relea... |
1613 |
/* we mustn't call path_put() as that would clear mnt_expiry_mark */ |
2d8f30380 [PATCH] sanitize ... |
1614 |
dput(path.dentry); |
900148dca vfs: spread struc... |
1615 |
mntput_no_expire(mnt); |
1da177e4c Linux-2.6.12-rc2 |
1616 1617 1618 |
out: return retval; } |
3a18ef5c1 fs: add ksys_umou... |
1619 1620 1621 1622 |
SYSCALL_DEFINE2(umount, char __user *, name, int, flags) { return ksys_umount(name, flags); } |
1da177e4c Linux-2.6.12-rc2 |
1623 1624 1625 |
#ifdef __ARCH_WANT_SYS_OLDUMOUNT /* |
b58fed8b1 [PATCH] lindent f... |
1626 |
* The 2.0 compatible umount. No flags. |
1da177e4c Linux-2.6.12-rc2 |
1627 |
*/ |
bdc480e3b [CVE-2009-0029] S... |
1628 |
SYSCALL_DEFINE1(oldumount, char __user *, name) |
1da177e4c Linux-2.6.12-rc2 |
1629 |
{ |
3a18ef5c1 fs: add ksys_umou... |
1630 |
return ksys_umount(name, 0); |
1da177e4c Linux-2.6.12-rc2 |
1631 1632 1633 |
} #endif |
4ce5d2b1a vfs: Don't copy m... |
1634 |
static bool is_mnt_ns_file(struct dentry *dentry) |
8823c079b vfs: Add setns su... |
1635 |
{ |
4ce5d2b1a vfs: Don't copy m... |
1636 |
/* Is this a proxy for a mount namespace? */ |
e149ed2b8 take the targets ... |
1637 1638 |
return dentry->d_op == &ns_dentry_operations && dentry->d_fsdata == &mntns_operations; |
4ce5d2b1a vfs: Don't copy m... |
1639 |
} |
58be28256 make mntns ->get(... |
1640 1641 1642 1643 |
struct mnt_namespace *to_mnt_ns(struct ns_common *ns) { return container_of(ns, struct mnt_namespace, ns); } |
4ce5d2b1a vfs: Don't copy m... |
1644 1645 1646 1647 1648 1649 1650 1651 |
static bool mnt_ns_loop(struct dentry *dentry) { /* Could bind mounting the mount namespace inode cause a * mount namespace loop? */ struct mnt_namespace *mnt_ns; if (!is_mnt_ns_file(dentry)) return false; |
f77c80142 bury struct proc_... |
1652 |
mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode)); |
8823c079b vfs: Add setns su... |
1653 1654 |
return current->nsproxy->mnt_ns->seq >= mnt_ns->seq; } |
87129cc0e vfs: spread struc... |
1655 |
struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, |
36341f645 [PATCH] mount exp... |
1656 |
int flag) |
1da177e4c Linux-2.6.12-rc2 |
1657 |
{ |
84d17192d get rid of full-h... |
1658 |
struct mount *res, *p, *q, *r, *parent; |
1da177e4c Linux-2.6.12-rc2 |
1659 |
|
4ce5d2b1a vfs: Don't copy m... |
1660 1661 1662 1663 |
if (!(flag & CL_COPY_UNBINDABLE) && IS_MNT_UNBINDABLE(mnt)) return ERR_PTR(-EINVAL); if (!(flag & CL_COPY_MNT_NS_FILE) && is_mnt_ns_file(dentry)) |
be34d1a3b VFS: Make clone_m... |
1664 |
return ERR_PTR(-EINVAL); |
9676f0c63 [PATCH] unbindabl... |
1665 |
|
36341f645 [PATCH] mount exp... |
1666 |
res = q = clone_mnt(mnt, dentry, flag); |
be34d1a3b VFS: Make clone_m... |
1667 1668 |
if (IS_ERR(q)) return q; |
a73324da7 vfs: move mnt_mou... |
1669 |
q->mnt_mountpoint = mnt->mnt_mountpoint; |
1da177e4c Linux-2.6.12-rc2 |
1670 1671 |
p = mnt; |
6b41d536f vfs: take mnt_chi... |
1672 |
list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) { |
315fc83e5 vfs: spread struc... |
1673 |
struct mount *s; |
7ec02ef15 vfs: remove lives... |
1674 |
if (!is_subdir(r->mnt_mountpoint, dentry)) |
1da177e4c Linux-2.6.12-rc2 |
1675 |
continue; |
909b0a88e vfs: spread struc... |
1676 |
for (s = r; s; s = next_mnt(s, r)) { |
4ce5d2b1a vfs: Don't copy m... |
1677 1678 |
if (!(flag & CL_COPY_UNBINDABLE) && IS_MNT_UNBINDABLE(s)) { |
df7342b24 mount: Don't allo... |
1679 1680 1681 1682 1683 1684 1685 1686 |
if (s->mnt.mnt_flags & MNT_LOCKED) { /* Both unbindable and locked. */ q = ERR_PTR(-EPERM); goto out; } else { s = skip_mnt_tree(s); continue; } |
4ce5d2b1a vfs: Don't copy m... |
1687 1688 1689 |
} if (!(flag & CL_COPY_MNT_NS_FILE) && is_mnt_ns_file(s->mnt.mnt_root)) { |
9676f0c63 [PATCH] unbindabl... |
1690 1691 1692 |
s = skip_mnt_tree(s); continue; } |
0714a5338 vfs: now it can b... |
1693 1694 1695 |
while (p != s->mnt_parent) { p = p->mnt_parent; q = q->mnt_parent; |
1da177e4c Linux-2.6.12-rc2 |
1696 |
} |
87129cc0e vfs: spread struc... |
1697 |
p = s; |
84d17192d get rid of full-h... |
1698 |
parent = q; |
87129cc0e vfs: spread struc... |
1699 |
q = clone_mnt(p, p->mnt.mnt_root, flag); |
be34d1a3b VFS: Make clone_m... |
1700 1701 |
if (IS_ERR(q)) goto out; |
719ea2fbb new helpers: lock... |
1702 |
lock_mount_hash(); |
1a4eeaf2a vfs: move mnt_lis... |
1703 |
list_add_tail(&q->mnt_list, &res->mnt_list); |
1064f874a mnt: Tuck mounts ... |
1704 |
attach_mnt(q, parent, p->mnt_mp); |
719ea2fbb new helpers: lock... |
1705 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1706 1707 1708 |
} } return res; |
be34d1a3b VFS: Make clone_m... |
1709 |
out: |
1da177e4c Linux-2.6.12-rc2 |
1710 |
if (res) { |
719ea2fbb new helpers: lock... |
1711 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
1712 |
umount_tree(res, UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
1713 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1714 |
} |
be34d1a3b VFS: Make clone_m... |
1715 |
return q; |
1da177e4c Linux-2.6.12-rc2 |
1716 |
} |
be34d1a3b VFS: Make clone_m... |
1717 |
/* Caller should check returned pointer for errors */ |
ca71cf71e namespace.c: cons... |
1718 |
struct vfsmount *collect_mounts(const struct path *path) |
8aec08094 [PATCH] new helpe... |
1719 |
{ |
cb338d06e vfs: spread struc... |
1720 |
struct mount *tree; |
97216be09 fold release_moun... |
1721 |
namespace_lock(); |
cd4a40174 mnt: Fail collect... |
1722 1723 1724 1725 1726 |
if (!check_mnt(real_mount(path->mnt))) tree = ERR_PTR(-EINVAL); else tree = copy_tree(real_mount(path->mnt), path->dentry, CL_COPY_ALL | CL_PRIVATE); |
328e6d901 switch unlock_mou... |
1727 |
namespace_unlock(); |
be34d1a3b VFS: Make clone_m... |
1728 |
if (IS_ERR(tree)) |
52e220d35 VFS: collect_moun... |
1729 |
return ERR_CAST(tree); |
be34d1a3b VFS: Make clone_m... |
1730 |
return &tree->mnt; |
8aec08094 [PATCH] new helpe... |
1731 |
} |
a07b20004 vfs: syscall: Add... |
1732 1733 1734 1735 1736 1737 1738 1739 1740 |
static void free_mnt_ns(struct mnt_namespace *); static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *, bool); void dissolve_on_fput(struct vfsmount *mnt) { struct mnt_namespace *ns; namespace_lock(); lock_mount_hash(); ns = real_mount(mnt)->mnt_ns; |
44dfd84a6 teach move_mount(... |
1741 1742 1743 1744 1745 1746 |
if (ns) { if (is_anon_ns(ns)) umount_tree(real_mount(mnt), UMOUNT_CONNECTED); else ns = NULL; } |
a07b20004 vfs: syscall: Add... |
1747 1748 |
unlock_mount_hash(); namespace_unlock(); |
44dfd84a6 teach move_mount(... |
1749 1750 |
if (ns) free_mnt_ns(ns); |
a07b20004 vfs: syscall: Add... |
1751 |
} |
8aec08094 [PATCH] new helpe... |
1752 1753 |
void drop_collected_mounts(struct vfsmount *mnt) { |
97216be09 fold release_moun... |
1754 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
1755 |
lock_mount_hash(); |
9c8e0a1b6 mount: Prevent MN... |
1756 |
umount_tree(real_mount(mnt), 0); |
719ea2fbb new helpers: lock... |
1757 |
unlock_mount_hash(); |
3ab6abee5 more conversions ... |
1758 |
namespace_unlock(); |
8aec08094 [PATCH] new helpe... |
1759 |
} |
c771d683a vfs: introduce cl... |
1760 1761 1762 1763 1764 1765 1766 1767 1768 |
/** * clone_private_mount - create a private clone of a path * * This creates a new vfsmount, which will be the clone of @path. The new will * not be attached anywhere in the namespace and will be private (i.e. changes * to the originating mount won't be propagated into this). * * Release with mntput(). */ |
ca71cf71e namespace.c: cons... |
1769 |
struct vfsmount *clone_private_mount(const struct path *path) |
c771d683a vfs: introduce cl... |
1770 1771 1772 1773 1774 1775 |
{ struct mount *old_mnt = real_mount(path->mnt); struct mount *new_mnt; if (IS_MNT_UNBINDABLE(old_mnt)) return ERR_PTR(-EINVAL); |
c771d683a vfs: introduce cl... |
1776 |
new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE); |
c771d683a vfs: introduce cl... |
1777 1778 1779 1780 1781 1782 |
if (IS_ERR(new_mnt)) return ERR_CAST(new_mnt); return &new_mnt->mnt; } EXPORT_SYMBOL_GPL(clone_private_mount); |
1f707137b new helper: itera... |
1783 1784 1785 |
int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, struct vfsmount *root) { |
1a4eeaf2a vfs: move mnt_lis... |
1786 |
struct mount *mnt; |
1f707137b new helper: itera... |
1787 1788 1789 |
int res = f(root, arg); if (res) return res; |
1a4eeaf2a vfs: move mnt_lis... |
1790 1791 |
list_for_each_entry(mnt, &real_mount(root)->mnt_list, mnt_list) { res = f(&mnt->mnt, arg); |
1f707137b new helper: itera... |
1792 1793 1794 1795 1796 |
if (res) return res; } return 0; } |
3bd045cc9 separate copying ... |
1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 |
static void lock_mnt_tree(struct mount *mnt) { struct mount *p; for (p = mnt; p; p = next_mnt(p, mnt)) { int flags = p->mnt.mnt_flags; /* Don't allow unprivileged users to change mount flags */ flags |= MNT_LOCK_ATIME; if (flags & MNT_READONLY) flags |= MNT_LOCK_READONLY; if (flags & MNT_NODEV) flags |= MNT_LOCK_NODEV; if (flags & MNT_NOSUID) flags |= MNT_LOCK_NOSUID; if (flags & MNT_NOEXEC) flags |= MNT_LOCK_NOEXEC; /* Don't allow unprivileged users to reveal what is under a mount */ if (list_empty(&p->mnt_expire)) flags |= MNT_LOCKED; p->mnt.mnt_flags = flags; } } |
4b8b21f4f vfs: spread struc... |
1823 |
static void cleanup_group_ids(struct mount *mnt, struct mount *end) |
719f5d7f0 [patch 4/7] vfs: ... |
1824 |
{ |
315fc83e5 vfs: spread struc... |
1825 |
struct mount *p; |
719f5d7f0 [patch 4/7] vfs: ... |
1826 |
|
909b0a88e vfs: spread struc... |
1827 |
for (p = mnt; p != end; p = next_mnt(p, mnt)) { |
fc7be130c vfs: switch pnode... |
1828 |
if (p->mnt_group_id && !IS_MNT_SHARED(p)) |
4b8b21f4f vfs: spread struc... |
1829 |
mnt_release_group_id(p); |
719f5d7f0 [patch 4/7] vfs: ... |
1830 1831 |
} } |
4b8b21f4f vfs: spread struc... |
1832 |
static int invent_group_ids(struct mount *mnt, bool recurse) |
719f5d7f0 [patch 4/7] vfs: ... |
1833 |
{ |
315fc83e5 vfs: spread struc... |
1834 |
struct mount *p; |
719f5d7f0 [patch 4/7] vfs: ... |
1835 |
|
909b0a88e vfs: spread struc... |
1836 |
for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) { |
fc7be130c vfs: switch pnode... |
1837 |
if (!p->mnt_group_id && !IS_MNT_SHARED(p)) { |
4b8b21f4f vfs: spread struc... |
1838 |
int err = mnt_alloc_group_id(p); |
719f5d7f0 [patch 4/7] vfs: ... |
1839 |
if (err) { |
4b8b21f4f vfs: spread struc... |
1840 |
cleanup_group_ids(mnt, p); |
719f5d7f0 [patch 4/7] vfs: ... |
1841 1842 1843 1844 1845 1846 1847 |
return err; } } } return 0; } |
d29216842 mnt: Add a per mo... |
1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 |
int count_mounts(struct mnt_namespace *ns, struct mount *mnt) { unsigned int max = READ_ONCE(sysctl_mount_max); unsigned int mounts = 0, old, pending, sum; struct mount *p; for (p = mnt; p; p = next_mnt(p, mnt)) mounts++; old = ns->mounts; pending = ns->pending_mounts; sum = old + pending; if ((old > sum) || (pending > sum) || (max < sum) || (mounts > (max - sum))) return -ENOSPC; ns->pending_mounts = pending + mounts; return 0; } |
b90fa9ae8 [PATCH] shared mo... |
1869 1870 |
/* * @source_mnt : mount tree to be attached |
214444032 [PATCH] shared mo... |
1871 1872 1873 1874 |
* @nd : place the mount tree @source_mnt is attached * @parent_nd : if non-null, detach the source_mnt from its parent and * store the parent mount and mountpoint dentry. * (done when source_mnt is moved) |
b90fa9ae8 [PATCH] shared mo... |
1875 1876 1877 |
* * NOTE: in the table below explains the semantics when a source mount * of a given type is attached to a destination mount of a given type. |
9676f0c63 [PATCH] unbindabl... |
1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 |
* --------------------------------------------------------------------------- * | BIND MOUNT OPERATION | * |************************************************************************** * | source-->| shared | private | slave | unbindable | * | dest | | | | | * | | | | | | | * | v | | | | | * |************************************************************************** * | shared | shared (++) | shared (+) | shared(+++)| invalid | * | | | | | | * |non-shared| shared (+) | private | slave (*) | invalid | * *************************************************************************** |
b90fa9ae8 [PATCH] shared mo... |
1890 1891 1892 1893 1894 1895 1896 1897 1898 |
* A bind operation clones the source mount and mounts the clone on the * destination mount. * * (++) the cloned mount is propagated to all the mounts in the propagation * tree of the destination mount and the cloned mount is added to * the peer group of the source mount. * (+) the cloned mount is created under the destination mount and is marked * as shared. The cloned mount is added to the peer group of the source * mount. |
5afe00221 [PATCH] handling ... |
1899 1900 1901 1902 1903 1904 1905 |
* (+++) the mount is propagated to all the mounts in the propagation tree * of the destination mount and the cloned mount is made slave * of the same master as that of the source mount. The cloned mount * is marked as 'shared and slave'. * (*) the cloned mount is made a slave of the same master as that of the * source mount. * |
9676f0c63 [PATCH] unbindabl... |
1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 |
* --------------------------------------------------------------------------- * | MOVE MOUNT OPERATION | * |************************************************************************** * | source-->| shared | private | slave | unbindable | * | dest | | | | | * | | | | | | | * | v | | | | | * |************************************************************************** * | shared | shared (+) | shared (+) | shared(+++) | invalid | * | | | | | | * |non-shared| shared (+*) | private | slave (*) | unbindable | * *************************************************************************** |
5afe00221 [PATCH] handling ... |
1918 1919 1920 |
* * (+) the mount is moved to the destination. And is then propagated to * all the mounts in the propagation tree of the destination mount. |
214444032 [PATCH] shared mo... |
1921 |
* (+*) the mount is moved to the destination. |
5afe00221 [PATCH] handling ... |
1922 1923 1924 1925 |
* (+++) the mount is moved to the destination and is then propagated to * all the mounts belonging to the destination mount's propagation tree. * the mount is marked as 'shared and slave'. * (*) the mount continues to be a slave at the new location. |
b90fa9ae8 [PATCH] shared mo... |
1926 1927 1928 1929 1930 1931 |
* * if the source mount is a tree, the operations explained above is * applied to each mount in the tree. * Must be called without spinlocks held, since this function can sleep * in allocations. */ |
0fb54e505 vfs: spread struc... |
1932 |
static int attach_recursive_mnt(struct mount *source_mnt, |
84d17192d get rid of full-h... |
1933 1934 |
struct mount *dest_mnt, struct mountpoint *dest_mp, |
2763d1191 get rid of detach... |
1935 |
bool moving) |
b90fa9ae8 [PATCH] shared mo... |
1936 |
{ |
3bd045cc9 separate copying ... |
1937 |
struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns; |
38129a13e switch mnt_hash t... |
1938 |
HLIST_HEAD(tree_list); |
d29216842 mnt: Add a per mo... |
1939 |
struct mnt_namespace *ns = dest_mnt->mnt_ns; |
1064f874a mnt: Tuck mounts ... |
1940 |
struct mountpoint *smp; |
315fc83e5 vfs: spread struc... |
1941 |
struct mount *child, *p; |
38129a13e switch mnt_hash t... |
1942 |
struct hlist_node *n; |
719f5d7f0 [patch 4/7] vfs: ... |
1943 |
int err; |
b90fa9ae8 [PATCH] shared mo... |
1944 |
|
1064f874a mnt: Tuck mounts ... |
1945 1946 1947 1948 1949 1950 |
/* Preallocate a mountpoint in case the new mounts need * to be tucked under other mounts. */ smp = get_mountpoint(source_mnt->mnt.mnt_root); if (IS_ERR(smp)) return PTR_ERR(smp); |
d29216842 mnt: Add a per mo... |
1951 |
/* Is there space to add these mounts to the mount namespace? */ |
2763d1191 get rid of detach... |
1952 |
if (!moving) { |
d29216842 mnt: Add a per mo... |
1953 1954 1955 1956 |
err = count_mounts(ns, source_mnt); if (err) goto out; } |
fc7be130c vfs: switch pnode... |
1957 |
if (IS_MNT_SHARED(dest_mnt)) { |
0fb54e505 vfs: spread struc... |
1958 |
err = invent_group_ids(source_mnt, true); |
719f5d7f0 [patch 4/7] vfs: ... |
1959 1960 |
if (err) goto out; |
0b1b901b5 don't bother with... |
1961 |
err = propagate_mnt(dest_mnt, dest_mp, source_mnt, &tree_list); |
f2ebb3a92 smarter propagate... |
1962 |
lock_mount_hash(); |
0b1b901b5 don't bother with... |
1963 1964 |
if (err) goto out_cleanup_ids; |
909b0a88e vfs: spread struc... |
1965 |
for (p = source_mnt; p; p = next_mnt(p, source_mnt)) |
0f0afb1dc vfs: spread struc... |
1966 |
set_mnt_shared(p); |
0b1b901b5 don't bother with... |
1967 1968 |
} else { lock_mount_hash(); |
b90fa9ae8 [PATCH] shared mo... |
1969 |
} |
2763d1191 get rid of detach... |
1970 1971 |
if (moving) { unhash_mnt(source_mnt); |
84d17192d get rid of full-h... |
1972 |
attach_mnt(source_mnt, dest_mnt, dest_mp); |
143c8c91c vfs: mnt_ns moved... |
1973 |
touch_mnt_namespace(source_mnt->mnt_ns); |
214444032 [PATCH] shared mo... |
1974 |
} else { |
44dfd84a6 teach move_mount(... |
1975 1976 1977 1978 |
if (source_mnt->mnt_ns) { /* move from anon - the caller will destroy */ list_del_init(&source_mnt->mnt_ns->list); } |
84d17192d get rid of full-h... |
1979 |
mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); |
1064f874a mnt: Tuck mounts ... |
1980 |
commit_tree(source_mnt); |
214444032 [PATCH] shared mo... |
1981 |
} |
b90fa9ae8 [PATCH] shared mo... |
1982 |
|
38129a13e switch mnt_hash t... |
1983 |
hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) { |
1d6a32acd keep shadowed vfs... |
1984 |
struct mount *q; |
38129a13e switch mnt_hash t... |
1985 |
hlist_del_init(&child->mnt_hash); |
1064f874a mnt: Tuck mounts ... |
1986 1987 1988 1989 |
q = __lookup_mnt(&child->mnt_parent->mnt, child->mnt_mountpoint); if (q) mnt_change_mountpoint(child, smp, q); |
3bd045cc9 separate copying ... |
1990 1991 1992 |
/* Notice when we are propagating across user namespaces */ if (child->mnt_parent->mnt_ns->user_ns != user_ns) lock_mnt_tree(child); |
d728cf791 fs/namespace: fix... |
1993 |
child->mnt.mnt_flags &= ~MNT_LOCKED; |
1064f874a mnt: Tuck mounts ... |
1994 |
commit_tree(child); |
b90fa9ae8 [PATCH] shared mo... |
1995 |
} |
1064f874a mnt: Tuck mounts ... |
1996 |
put_mountpoint(smp); |
719ea2fbb new helpers: lock... |
1997 |
unlock_mount_hash(); |
99b7db7b8 fs: brlock vfsmou... |
1998 |
|
b90fa9ae8 [PATCH] shared mo... |
1999 |
return 0; |
719f5d7f0 [patch 4/7] vfs: ... |
2000 2001 |
out_cleanup_ids: |
f2ebb3a92 smarter propagate... |
2002 2003 |
while (!hlist_empty(&tree_list)) { child = hlist_entry(tree_list.first, struct mount, mnt_hash); |
d29216842 mnt: Add a per mo... |
2004 |
child->mnt_parent->mnt_ns->pending_mounts = 0; |
e819f1521 mnt: Improve the ... |
2005 |
umount_tree(child, UMOUNT_SYNC); |
f2ebb3a92 smarter propagate... |
2006 2007 |
} unlock_mount_hash(); |
0b1b901b5 don't bother with... |
2008 |
cleanup_group_ids(source_mnt, NULL); |
719f5d7f0 [patch 4/7] vfs: ... |
2009 |
out: |
d29216842 mnt: Add a per mo... |
2010 |
ns->pending_mounts = 0; |
1064f874a mnt: Tuck mounts ... |
2011 2012 2013 2014 |
read_seqlock_excl(&mount_lock); put_mountpoint(smp); read_sequnlock_excl(&mount_lock); |
719f5d7f0 [patch 4/7] vfs: ... |
2015 |
return err; |
b90fa9ae8 [PATCH] shared mo... |
2016 |
} |
84d17192d get rid of full-h... |
2017 |
static struct mountpoint *lock_mount(struct path *path) |
b12cea919 change the lockin... |
2018 2019 |
{ struct vfsmount *mnt; |
84d17192d get rid of full-h... |
2020 |
struct dentry *dentry = path->dentry; |
b12cea919 change the lockin... |
2021 |
retry: |
5955102c9 wrappers for ->i_... |
2022 |
inode_lock(dentry->d_inode); |
84d17192d get rid of full-h... |
2023 |
if (unlikely(cant_mount(dentry))) { |
5955102c9 wrappers for ->i_... |
2024 |
inode_unlock(dentry->d_inode); |
84d17192d get rid of full-h... |
2025 |
return ERR_PTR(-ENOENT); |
b12cea919 change the lockin... |
2026 |
} |
97216be09 fold release_moun... |
2027 |
namespace_lock(); |
b12cea919 change the lockin... |
2028 |
mnt = lookup_mnt(path); |
84d17192d get rid of full-h... |
2029 |
if (likely(!mnt)) { |
3895dbf89 mnt: Protect the ... |
2030 |
struct mountpoint *mp = get_mountpoint(dentry); |
84d17192d get rid of full-h... |
2031 |
if (IS_ERR(mp)) { |
97216be09 fold release_moun... |
2032 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
2033 |
inode_unlock(dentry->d_inode); |
84d17192d get rid of full-h... |
2034 2035 2036 2037 |
return mp; } return mp; } |
97216be09 fold release_moun... |
2038 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
2039 |
inode_unlock(path->dentry->d_inode); |
b12cea919 change the lockin... |
2040 2041 |
path_put(path); path->mnt = mnt; |
84d17192d get rid of full-h... |
2042 |
dentry = path->dentry = dget(mnt->mnt_root); |
b12cea919 change the lockin... |
2043 2044 |
goto retry; } |
84d17192d get rid of full-h... |
2045 |
static void unlock_mount(struct mountpoint *where) |
b12cea919 change the lockin... |
2046 |
{ |
84d17192d get rid of full-h... |
2047 |
struct dentry *dentry = where->m_dentry; |
3895dbf89 mnt: Protect the ... |
2048 2049 |
read_seqlock_excl(&mount_lock); |
84d17192d get rid of full-h... |
2050 |
put_mountpoint(where); |
3895dbf89 mnt: Protect the ... |
2051 |
read_sequnlock_excl(&mount_lock); |
328e6d901 switch unlock_mou... |
2052 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
2053 |
inode_unlock(dentry->d_inode); |
b12cea919 change the lockin... |
2054 |
} |
84d17192d get rid of full-h... |
2055 |
static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp) |
1da177e4c Linux-2.6.12-rc2 |
2056 |
{ |
e462ec50c VFS: Differentiat... |
2057 |
if (mnt->mnt.mnt_sb->s_flags & SB_NOUSER) |
1da177e4c Linux-2.6.12-rc2 |
2058 |
return -EINVAL; |
e36cb0b89 VFS: (Scripted) C... |
2059 2060 |
if (d_is_dir(mp->m_dentry) != d_is_dir(mnt->mnt.mnt_root)) |
1da177e4c Linux-2.6.12-rc2 |
2061 |
return -ENOTDIR; |
2763d1191 get rid of detach... |
2062 |
return attach_recursive_mnt(mnt, p, mp, false); |
1da177e4c Linux-2.6.12-rc2 |
2063 2064 2065 |
} /* |
7a2e8a8fa VFS: Sanity check... |
2066 2067 |
* Sanity check the flags to change_mnt_propagation. */ |
e462ec50c VFS: Differentiat... |
2068 |
static int flags_to_propagation_type(int ms_flags) |
7a2e8a8fa VFS: Sanity check... |
2069 |
{ |
e462ec50c VFS: Differentiat... |
2070 |
int type = ms_flags & ~(MS_REC | MS_SILENT); |
7a2e8a8fa VFS: Sanity check... |
2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 |
/* Fail if any non-propagation flags are set */ if (type & ~(MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) return 0; /* Only one propagation flag should be set */ if (!is_power_of_2(type)) return 0; return type; } /* |
07b20889e [PATCH] beginning... |
2082 2083 |
* recursively change the type of the mountpoint. */ |
e462ec50c VFS: Differentiat... |
2084 |
static int do_change_type(struct path *path, int ms_flags) |
07b20889e [PATCH] beginning... |
2085 |
{ |
315fc83e5 vfs: spread struc... |
2086 |
struct mount *m; |
4b8b21f4f vfs: spread struc... |
2087 |
struct mount *mnt = real_mount(path->mnt); |
e462ec50c VFS: Differentiat... |
2088 |
int recurse = ms_flags & MS_REC; |
7a2e8a8fa VFS: Sanity check... |
2089 |
int type; |
719f5d7f0 [patch 4/7] vfs: ... |
2090 |
int err = 0; |
07b20889e [PATCH] beginning... |
2091 |
|
2d92ab3c6 [PATCH] finally g... |
2092 |
if (path->dentry != path->mnt->mnt_root) |
07b20889e [PATCH] beginning... |
2093 |
return -EINVAL; |
e462ec50c VFS: Differentiat... |
2094 |
type = flags_to_propagation_type(ms_flags); |
7a2e8a8fa VFS: Sanity check... |
2095 2096 |
if (!type) return -EINVAL; |
97216be09 fold release_moun... |
2097 |
namespace_lock(); |
719f5d7f0 [patch 4/7] vfs: ... |
2098 2099 2100 2101 2102 |
if (type == MS_SHARED) { err = invent_group_ids(mnt, recurse); if (err) goto out_unlock; } |
719ea2fbb new helpers: lock... |
2103 |
lock_mount_hash(); |
909b0a88e vfs: spread struc... |
2104 |
for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL)) |
0f0afb1dc vfs: spread struc... |
2105 |
change_mnt_propagation(m, type); |
719ea2fbb new helpers: lock... |
2106 |
unlock_mount_hash(); |
719f5d7f0 [patch 4/7] vfs: ... |
2107 2108 |
out_unlock: |
97216be09 fold release_moun... |
2109 |
namespace_unlock(); |
719f5d7f0 [patch 4/7] vfs: ... |
2110 |
return err; |
07b20889e [PATCH] beginning... |
2111 |
} |
5ff9d8a65 vfs: Lock in plac... |
2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 |
static bool has_locked_children(struct mount *mnt, struct dentry *dentry) { struct mount *child; list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { if (!is_subdir(child->mnt_mountpoint, dentry)) continue; if (child->mnt.mnt_flags & MNT_LOCKED) return true; } return false; } |
a07b20004 vfs: syscall: Add... |
2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 |
static struct mount *__do_loopback(struct path *old_path, int recurse) { struct mount *mnt = ERR_PTR(-EINVAL), *old = real_mount(old_path->mnt); if (IS_MNT_UNBINDABLE(old)) return mnt; if (!check_mnt(old) && old_path->dentry->d_op != &ns_dentry_operations) return mnt; if (!recurse && has_locked_children(old, old_path->dentry)) return mnt; if (recurse) mnt = copy_tree(old, old_path->dentry, CL_COPY_MNT_NS_FILE); else mnt = clone_mnt(old, old_path->dentry, 0); if (!IS_ERR(mnt)) mnt->mnt.mnt_flags &= ~MNT_LOCKED; return mnt; } |
07b20889e [PATCH] beginning... |
2147 |
/* |
1da177e4c Linux-2.6.12-rc2 |
2148 2149 |
* do loopback mount. */ |
808d4e3cf consitify do_moun... |
2150 |
static int do_loopback(struct path *path, const char *old_name, |
2dafe1c4d reduce large do_m... |
2151 |
int recurse) |
1da177e4c Linux-2.6.12-rc2 |
2152 |
{ |
2d92ab3c6 [PATCH] finally g... |
2153 |
struct path old_path; |
a07b20004 vfs: syscall: Add... |
2154 |
struct mount *mnt = NULL, *parent; |
84d17192d get rid of full-h... |
2155 |
struct mountpoint *mp; |
57eccb830 mount: consolidat... |
2156 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2157 2158 |
if (!old_name || !*old_name) return -EINVAL; |
815d405ce VFS: Fix the rema... |
2159 |
err = kern_path(old_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path); |
1da177e4c Linux-2.6.12-rc2 |
2160 2161 |
if (err) return err; |
8823c079b vfs: Add setns su... |
2162 |
err = -EINVAL; |
4ce5d2b1a vfs: Don't copy m... |
2163 |
if (mnt_ns_loop(old_path.dentry)) |
dd111b31e VFS: Clean up whi... |
2164 |
goto out; |
8823c079b vfs: Add setns su... |
2165 |
|
84d17192d get rid of full-h... |
2166 |
mp = lock_mount(path); |
a07b20004 vfs: syscall: Add... |
2167 2168 |
if (IS_ERR(mp)) { err = PTR_ERR(mp); |
b12cea919 change the lockin... |
2169 |
goto out; |
a07b20004 vfs: syscall: Add... |
2170 |
} |
b12cea919 change the lockin... |
2171 |
|
84d17192d get rid of full-h... |
2172 |
parent = real_mount(path->mnt); |
e149ed2b8 take the targets ... |
2173 2174 |
if (!check_mnt(parent)) goto out2; |
a07b20004 vfs: syscall: Add... |
2175 |
mnt = __do_loopback(&old_path, recurse); |
be34d1a3b VFS: Make clone_m... |
2176 2177 |
if (IS_ERR(mnt)) { err = PTR_ERR(mnt); |
e9c5d8a56 mnt: release lock... |
2178 |
goto out2; |
be34d1a3b VFS: Make clone_m... |
2179 |
} |
ccd48bc7f [PATCH] cleanups ... |
2180 |
|
84d17192d get rid of full-h... |
2181 |
err = graft_tree(mnt, parent, mp); |
ccd48bc7f [PATCH] cleanups ... |
2182 |
if (err) { |
719ea2fbb new helpers: lock... |
2183 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
2184 |
umount_tree(mnt, UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
2185 |
unlock_mount_hash(); |
5b83d2c5c [PATCH] sanitize ... |
2186 |
} |
b12cea919 change the lockin... |
2187 |
out2: |
84d17192d get rid of full-h... |
2188 |
unlock_mount(mp); |
ccd48bc7f [PATCH] cleanups ... |
2189 |
out: |
2d92ab3c6 [PATCH] finally g... |
2190 |
path_put(&old_path); |
1da177e4c Linux-2.6.12-rc2 |
2191 2192 |
return err; } |
a07b20004 vfs: syscall: Add... |
2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 |
static struct file *open_detached_copy(struct path *path, bool recursive) { struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns; struct mnt_namespace *ns = alloc_mnt_ns(user_ns, true); struct mount *mnt, *p; struct file *file; if (IS_ERR(ns)) return ERR_CAST(ns); namespace_lock(); mnt = __do_loopback(path, recursive); if (IS_ERR(mnt)) { namespace_unlock(); free_mnt_ns(ns); return ERR_CAST(mnt); } lock_mount_hash(); for (p = mnt; p; p = next_mnt(p, mnt)) { p->mnt_ns = ns; ns->mounts++; } ns->root = mnt; list_add_tail(&ns->list, &mnt->mnt_list); mntget(&mnt->mnt); unlock_mount_hash(); namespace_unlock(); mntput(path->mnt); path->mnt = &mnt->mnt; file = dentry_open(path, O_PATH, current_cred()); if (IS_ERR(file)) dissolve_on_fput(path->mnt); else file->f_mode |= FMODE_NEED_UNMOUNT; return file; } SYSCALL_DEFINE3(open_tree, int, dfd, const char *, filename, unsigned, flags) { struct file *file; struct path path; int lookup_flags = LOOKUP_AUTOMOUNT | LOOKUP_FOLLOW; bool detached = flags & OPEN_TREE_CLONE; int error; int fd; BUILD_BUG_ON(OPEN_TREE_CLOEXEC != O_CLOEXEC); if (flags & ~(AT_EMPTY_PATH | AT_NO_AUTOMOUNT | AT_RECURSIVE | AT_SYMLINK_NOFOLLOW | OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC)) return -EINVAL; if ((flags & (AT_RECURSIVE | OPEN_TREE_CLONE)) == AT_RECURSIVE) return -EINVAL; if (flags & AT_NO_AUTOMOUNT) lookup_flags &= ~LOOKUP_AUTOMOUNT; if (flags & AT_SYMLINK_NOFOLLOW) lookup_flags &= ~LOOKUP_FOLLOW; if (flags & AT_EMPTY_PATH) lookup_flags |= LOOKUP_EMPTY; if (detached && !may_mount()) return -EPERM; fd = get_unused_fd_flags(flags & O_CLOEXEC); if (fd < 0) return fd; error = user_path_at(dfd, filename, lookup_flags, &path); if (unlikely(error)) { file = ERR_PTR(error); } else { if (detached) file = open_detached_copy(&path, flags & AT_RECURSIVE); else file = dentry_open(&path, O_PATH, current_cred()); path_put(&path); } if (IS_ERR(file)) { put_unused_fd(fd); return PTR_ERR(file); } fd_install(fd, file); return fd; } |
43f5e655e vfs: Separate cha... |
2282 2283 2284 2285 2286 2287 2288 |
/* * Don't allow locked mount flags to be cleared. * * No locks need to be held here while testing the various MNT_LOCK * flags because those flags can never be cleared once they are set. */ static bool can_change_locked_flags(struct mount *mnt, unsigned int mnt_flags) |
2e4b7fcd9 [PATCH] r/o bind ... |
2289 |
{ |
43f5e655e vfs: Separate cha... |
2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 |
unsigned int fl = mnt->mnt.mnt_flags; if ((fl & MNT_LOCK_READONLY) && !(mnt_flags & MNT_READONLY)) return false; if ((fl & MNT_LOCK_NODEV) && !(mnt_flags & MNT_NODEV)) return false; if ((fl & MNT_LOCK_NOSUID) && !(mnt_flags & MNT_NOSUID)) return false; if ((fl & MNT_LOCK_NOEXEC) && !(mnt_flags & MNT_NOEXEC)) return false; if ((fl & MNT_LOCK_ATIME) && ((fl & MNT_ATIME_MASK) != (mnt_flags & MNT_ATIME_MASK))) return false; |
2e4b7fcd9 [PATCH] r/o bind ... |
2311 |
|
43f5e655e vfs: Separate cha... |
2312 2313 2314 2315 |
return true; } static int change_mount_ro_state(struct mount *mnt, unsigned int mnt_flags) |
2e4b7fcd9 [PATCH] r/o bind ... |
2316 |
{ |
43f5e655e vfs: Separate cha... |
2317 |
bool readonly_request = (mnt_flags & MNT_READONLY); |
2e4b7fcd9 [PATCH] r/o bind ... |
2318 |
|
43f5e655e vfs: Separate cha... |
2319 |
if (readonly_request == __mnt_is_readonly(&mnt->mnt)) |
2e4b7fcd9 [PATCH] r/o bind ... |
2320 2321 2322 |
return 0; if (readonly_request) |
43f5e655e vfs: Separate cha... |
2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 |
return mnt_make_readonly(mnt); return __mnt_unmake_readonly(mnt); } /* * Update the user-settable attributes on a mount. The caller must hold * sb->s_umount for writing. */ static void set_mount_attributes(struct mount *mnt, unsigned int mnt_flags) { lock_mount_hash(); mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK; mnt->mnt.mnt_flags = mnt_flags; touch_mnt_namespace(mnt->mnt_ns); unlock_mount_hash(); } |
f8b92ba67 mount: Add mount ... |
2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 |
static void mnt_warn_timestamp_expiry(struct path *mountpoint, struct vfsmount *mnt) { struct super_block *sb = mnt->mnt_sb; if (!__mnt_is_readonly(mnt) && (ktime_get_real_seconds() + TIME_UPTIME_SEC_MAX > sb->s_time_max)) { char *buf = (char *)__get_free_page(GFP_KERNEL); char *mntpath = buf ? d_path(mountpoint, buf, PAGE_SIZE) : ERR_PTR(-ENOMEM); struct tm tm; time64_to_tm(sb->s_time_max, 0, &tm); |
0ecee6699 fs/namespace.c: f... |
2351 2352 2353 2354 2355 |
pr_warn("%s filesystem being %s at %s supports timestamps until %04ld (0x%llx) ", sb->s_type->name, is_mounted(mnt) ? "remounted" : "mounted", mntpath, |
f8b92ba67 mount: Add mount ... |
2356 2357 2358 2359 2360 |
tm.tm_year+1900, (unsigned long long)sb->s_time_max); free_page((unsigned long)buf); } } |
43f5e655e vfs: Separate cha... |
2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 |
/* * Handle reconfiguration of the mountpoint only without alteration of the * superblock it refers to. This is triggered by specifying MS_REMOUNT|MS_BIND * to mount(2). */ static int do_reconfigure_mnt(struct path *path, unsigned int mnt_flags) { struct super_block *sb = path->mnt->mnt_sb; struct mount *mnt = real_mount(path->mnt); int ret; if (!check_mnt(mnt)) return -EINVAL; if (path->dentry != mnt->mnt.mnt_root) return -EINVAL; if (!can_change_locked_flags(mnt, mnt_flags)) return -EPERM; down_write(&sb->s_umount); ret = change_mount_ro_state(mnt, mnt_flags); if (ret == 0) set_mount_attributes(mnt, mnt_flags); up_write(&sb->s_umount); |
f8b92ba67 mount: Add mount ... |
2386 2387 |
mnt_warn_timestamp_expiry(path, &mnt->mnt); |
43f5e655e vfs: Separate cha... |
2388 |
return ret; |
2e4b7fcd9 [PATCH] r/o bind ... |
2389 |
} |
1da177e4c Linux-2.6.12-rc2 |
2390 2391 2392 2393 2394 |
/* * change filesystem flags. dir should be a physical root of filesystem. * If you've mounted a non-root directory somewhere and want to do remount * on it - tough luck. */ |
e462ec50c VFS: Differentiat... |
2395 2396 |
static int do_remount(struct path *path, int ms_flags, int sb_flags, int mnt_flags, void *data) |
1da177e4c Linux-2.6.12-rc2 |
2397 2398 |
{ int err; |
2d92ab3c6 [PATCH] finally g... |
2399 |
struct super_block *sb = path->mnt->mnt_sb; |
143c8c91c vfs: mnt_ns moved... |
2400 |
struct mount *mnt = real_mount(path->mnt); |
8d0347f6c convert do_remoun... |
2401 |
struct fs_context *fc; |
1da177e4c Linux-2.6.12-rc2 |
2402 |
|
143c8c91c vfs: mnt_ns moved... |
2403 |
if (!check_mnt(mnt)) |
1da177e4c Linux-2.6.12-rc2 |
2404 |
return -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2405 |
if (path->dentry != path->mnt->mnt_root) |
1da177e4c Linux-2.6.12-rc2 |
2406 |
return -EINVAL; |
43f5e655e vfs: Separate cha... |
2407 |
if (!can_change_locked_flags(mnt, mnt_flags)) |
9566d6742 mnt: Correct perm... |
2408 |
return -EPERM; |
9566d6742 mnt: Correct perm... |
2409 |
|
8d0347f6c convert do_remoun... |
2410 2411 2412 |
fc = fs_context_for_reconfigure(path->dentry, sb_flags, MS_RMT_MASK); if (IS_ERR(fc)) return PTR_ERR(fc); |
ff36fe2c8 LSM: Pass -o remo... |
2413 |
|
8d0347f6c convert do_remoun... |
2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 |
err = parse_monolithic_mount_data(fc, data); if (!err) { down_write(&sb->s_umount); err = -EPERM; if (ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) { err = reconfigure_super(fc); if (!err) set_mount_attributes(mnt, mnt_flags); } up_write(&sb->s_umount); |
0e55a7cca [RFC PATCH] touch... |
2424 |
} |
f8b92ba67 mount: Add mount ... |
2425 2426 |
mnt_warn_timestamp_expiry(path, &mnt->mnt); |
8d0347f6c convert do_remoun... |
2427 |
put_fs_context(fc); |
1da177e4c Linux-2.6.12-rc2 |
2428 2429 |
return err; } |
cbbe362cd vfs: spread struc... |
2430 |
static inline int tree_contains_unbindable(struct mount *mnt) |
9676f0c63 [PATCH] unbindabl... |
2431 |
{ |
315fc83e5 vfs: spread struc... |
2432 |
struct mount *p; |
909b0a88e vfs: spread struc... |
2433 |
for (p = mnt; p; p = next_mnt(p, mnt)) { |
fc7be130c vfs: switch pnode... |
2434 |
if (IS_MNT_UNBINDABLE(p)) |
9676f0c63 [PATCH] unbindabl... |
2435 2436 2437 2438 |
return 1; } return 0; } |
44dfd84a6 teach move_mount(... |
2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 |
/* * Check that there aren't references to earlier/same mount namespaces in the * specified subtree. Such references can act as pins for mount namespaces * that aren't checked by the mount-cycle checking code, thereby allowing * cycles to be made. */ static bool check_for_nsfs_mounts(struct mount *subtree) { struct mount *p; bool ret = false; lock_mount_hash(); for (p = subtree; p; p = next_mnt(p, subtree)) if (mnt_ns_loop(p->mnt.mnt_root)) goto out; ret = true; out: unlock_mount_hash(); return ret; } |
2db154b3e vfs: syscall: Add... |
2460 |
static int do_move_mount(struct path *old_path, struct path *new_path) |
1da177e4c Linux-2.6.12-rc2 |
2461 |
{ |
44dfd84a6 teach move_mount(... |
2462 |
struct mnt_namespace *ns; |
676da58df vfs: spread struc... |
2463 |
struct mount *p; |
0fb54e505 vfs: spread struc... |
2464 |
struct mount *old; |
2763d1191 get rid of detach... |
2465 2466 |
struct mount *parent; struct mountpoint *mp, *old_mp; |
57eccb830 mount: consolidat... |
2467 |
int err; |
44dfd84a6 teach move_mount(... |
2468 |
bool attached; |
1da177e4c Linux-2.6.12-rc2 |
2469 |
|
2db154b3e vfs: syscall: Add... |
2470 |
mp = lock_mount(new_path); |
84d17192d get rid of full-h... |
2471 |
if (IS_ERR(mp)) |
2db154b3e vfs: syscall: Add... |
2472 |
return PTR_ERR(mp); |
cc53ce53c Add a dentry op t... |
2473 |
|
2db154b3e vfs: syscall: Add... |
2474 2475 |
old = real_mount(old_path->mnt); p = real_mount(new_path->mnt); |
2763d1191 get rid of detach... |
2476 |
parent = old->mnt_parent; |
44dfd84a6 teach move_mount(... |
2477 |
attached = mnt_has_parent(old); |
2763d1191 get rid of detach... |
2478 |
old_mp = old->mnt_mp; |
44dfd84a6 teach move_mount(... |
2479 |
ns = old->mnt_ns; |
143c8c91c vfs: mnt_ns moved... |
2480 |
|
1da177e4c Linux-2.6.12-rc2 |
2481 |
err = -EINVAL; |
44dfd84a6 teach move_mount(... |
2482 2483 |
/* The mountpoint must be in our namespace. */ if (!check_mnt(p)) |
2db154b3e vfs: syscall: Add... |
2484 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
2485 |
|
570d7a98e vfs: move_mount: ... |
2486 2487 |
/* The thing moved must be mounted... */ if (!is_mounted(&old->mnt)) |
44dfd84a6 teach move_mount(... |
2488 |
goto out; |
570d7a98e vfs: move_mount: ... |
2489 2490 |
/* ... and either ours or the root of anon namespace */ if (!(attached ? check_mnt(old) : is_anon_ns(ns))) |
2db154b3e vfs: syscall: Add... |
2491 |
goto out; |
5ff9d8a65 vfs: Lock in plac... |
2492 |
|
2db154b3e vfs: syscall: Add... |
2493 2494 |
if (old->mnt.mnt_flags & MNT_LOCKED) goto out; |
1da177e4c Linux-2.6.12-rc2 |
2495 |
|
2db154b3e vfs: syscall: Add... |
2496 2497 |
if (old_path->dentry != old_path->mnt->mnt_root) goto out; |
1da177e4c Linux-2.6.12-rc2 |
2498 |
|
2db154b3e vfs: syscall: Add... |
2499 2500 2501 |
if (d_is_dir(new_path->dentry) != d_is_dir(old_path->dentry)) goto out; |
214444032 [PATCH] shared mo... |
2502 2503 2504 |
/* * Don't move a mount residing in a shared parent. */ |
2763d1191 get rid of detach... |
2505 |
if (attached && IS_MNT_SHARED(parent)) |
2db154b3e vfs: syscall: Add... |
2506 |
goto out; |
9676f0c63 [PATCH] unbindabl... |
2507 2508 2509 2510 |
/* * Don't move a mount tree containing unbindable mounts to a destination * mount which is shared. */ |
fc7be130c vfs: switch pnode... |
2511 |
if (IS_MNT_SHARED(p) && tree_contains_unbindable(old)) |
2db154b3e vfs: syscall: Add... |
2512 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
2513 |
err = -ELOOP; |
44dfd84a6 teach move_mount(... |
2514 2515 |
if (!check_for_nsfs_mounts(old)) goto out; |
fc7be130c vfs: switch pnode... |
2516 |
for (; mnt_has_parent(p); p = p->mnt_parent) |
676da58df vfs: spread struc... |
2517 |
if (p == old) |
2db154b3e vfs: syscall: Add... |
2518 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
2519 |
|
2db154b3e vfs: syscall: Add... |
2520 |
err = attach_recursive_mnt(old, real_mount(new_path->mnt), mp, |
2763d1191 get rid of detach... |
2521 |
attached); |
4ac913785 Embed a struct pa... |
2522 |
if (err) |
2db154b3e vfs: syscall: Add... |
2523 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
2524 2525 2526 |
/* if the mount is moved, it should no longer be expire * automatically */ |
6776db3d3 vfs: take mnt_sha... |
2527 |
list_del_init(&old->mnt_expire); |
2763d1191 get rid of detach... |
2528 2529 |
if (attached) put_mountpoint(old_mp); |
1da177e4c Linux-2.6.12-rc2 |
2530 |
out: |
2db154b3e vfs: syscall: Add... |
2531 |
unlock_mount(mp); |
44dfd84a6 teach move_mount(... |
2532 |
if (!err) { |
2763d1191 get rid of detach... |
2533 2534 2535 |
if (attached) mntput_no_expire(parent); else |
44dfd84a6 teach move_mount(... |
2536 2537 |
free_mnt_ns(ns); } |
2db154b3e vfs: syscall: Add... |
2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 |
return err; } static int do_move_mount_old(struct path *path, const char *old_name) { struct path old_path; int err; if (!old_name || !*old_name) return -EINVAL; err = kern_path(old_name, LOOKUP_FOLLOW, &old_path); if (err) return err; err = do_move_mount(&old_path, path); |
2d92ab3c6 [PATCH] finally g... |
2554 |
path_put(&old_path); |
1da177e4c Linux-2.6.12-rc2 |
2555 2556 |
return err; } |
9d412a43c vfs: split off vf... |
2557 2558 2559 |
/* * add a mount into a namespace's mount tree */ |
95bc5f25c vfs: spread struc... |
2560 |
static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags) |
9d412a43c vfs: split off vf... |
2561 |
{ |
84d17192d get rid of full-h... |
2562 2563 |
struct mountpoint *mp; struct mount *parent; |
9d412a43c vfs: split off vf... |
2564 |
int err; |
f2ebb3a92 smarter propagate... |
2565 |
mnt_flags &= ~MNT_INTERNAL_FLAGS; |
9d412a43c vfs: split off vf... |
2566 |
|
84d17192d get rid of full-h... |
2567 2568 2569 |
mp = lock_mount(path); if (IS_ERR(mp)) return PTR_ERR(mp); |
9d412a43c vfs: split off vf... |
2570 |
|
84d17192d get rid of full-h... |
2571 |
parent = real_mount(path->mnt); |
9d412a43c vfs: split off vf... |
2572 |
err = -EINVAL; |
84d17192d get rid of full-h... |
2573 |
if (unlikely(!check_mnt(parent))) { |
156cacb1d do_add_mount()/um... |
2574 2575 2576 2577 |
/* that's acceptable only for automounts done in private ns */ if (!(mnt_flags & MNT_SHRINKABLE)) goto unlock; /* ... and for those we'd better have mountpoint still alive */ |
84d17192d get rid of full-h... |
2578 |
if (!parent->mnt_ns) |
156cacb1d do_add_mount()/um... |
2579 2580 |
goto unlock; } |
9d412a43c vfs: split off vf... |
2581 2582 2583 |
/* Refuse the same filesystem on the same mount point */ err = -EBUSY; |
95bc5f25c vfs: spread struc... |
2584 |
if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb && |
9d412a43c vfs: split off vf... |
2585 2586 2587 2588 |
path->mnt->mnt_root == path->dentry) goto unlock; err = -EINVAL; |
e36cb0b89 VFS: (Scripted) C... |
2589 |
if (d_is_symlink(newmnt->mnt.mnt_root)) |
9d412a43c vfs: split off vf... |
2590 |
goto unlock; |
95bc5f25c vfs: spread struc... |
2591 |
newmnt->mnt.mnt_flags = mnt_flags; |
84d17192d get rid of full-h... |
2592 |
err = graft_tree(newmnt, parent, mp); |
9d412a43c vfs: split off vf... |
2593 2594 |
unlock: |
84d17192d get rid of full-h... |
2595 |
unlock_mount(mp); |
9d412a43c vfs: split off vf... |
2596 2597 |
return err; } |
b1e75df45 tidy up around fi... |
2598 |
|
132e46084 new helper: do_ne... |
2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 |
static bool mount_too_revealing(const struct super_block *sb, int *new_mnt_flags); /* * Create a new mount using a superblock configuration and request it * be added to the namespace tree. */ static int do_new_mount_fc(struct fs_context *fc, struct path *mountpoint, unsigned int mnt_flags) { struct vfsmount *mnt; struct super_block *sb = fc->root->d_sb; int error; |
c9ce29ed7 vfs_get_tree(): e... |
2611 2612 2613 2614 2615 2616 2617 |
error = security_sb_kern_mount(sb); if (!error && mount_too_revealing(sb, &mnt_flags)) error = -EPERM; if (unlikely(error)) { fc_drop_locked(fc); return error; |
132e46084 new helper: do_ne... |
2618 2619 2620 2621 2622 2623 2624 |
} up_write(&sb->s_umount); mnt = vfs_create_mount(fc); if (IS_ERR(mnt)) return PTR_ERR(mnt); |
f8b92ba67 mount: Add mount ... |
2625 |
mnt_warn_timestamp_expiry(mountpoint, mnt); |
0ecee6699 fs/namespace.c: f... |
2626 2627 2628 |
error = do_add_mount(real_mount(mnt), mountpoint, mnt_flags); if (error < 0) mntput(mnt); |
132e46084 new helper: do_ne... |
2629 2630 |
return error; } |
1b852bceb mnt: Refactor the... |
2631 |
|
1da177e4c Linux-2.6.12-rc2 |
2632 2633 2634 2635 |
/* * create a new mount for userspace and request it to be added into the * namespace's tree */ |
e462ec50c VFS: Differentiat... |
2636 |
static int do_new_mount(struct path *path, const char *fstype, int sb_flags, |
808d4e3cf consitify do_moun... |
2637 |
int mnt_flags, const char *name, void *data) |
1da177e4c Linux-2.6.12-rc2 |
2638 |
{ |
0c55cfc41 vfs: Allow unpriv... |
2639 |
struct file_system_type *type; |
a0c9a8b8f teach vfs_get_tre... |
2640 2641 2642 |
struct fs_context *fc; const char *subtype = NULL; int err = 0; |
1da177e4c Linux-2.6.12-rc2 |
2643 |
|
0c55cfc41 vfs: Allow unpriv... |
2644 |
if (!fstype) |
1da177e4c Linux-2.6.12-rc2 |
2645 |
return -EINVAL; |
0c55cfc41 vfs: Allow unpriv... |
2646 2647 2648 |
type = get_fs_type(fstype); if (!type) return -ENODEV; |
a0c9a8b8f teach vfs_get_tre... |
2649 2650 2651 2652 2653 2654 2655 2656 |
if (type->fs_flags & FS_HAS_SUBTYPE) { subtype = strchr(fstype, '.'); if (subtype) { subtype++; if (!*subtype) { put_filesystem(type); return -EINVAL; } |
a0c9a8b8f teach vfs_get_tre... |
2657 2658 |
} } |
0c55cfc41 vfs: Allow unpriv... |
2659 |
|
a0c9a8b8f teach vfs_get_tre... |
2660 |
fc = fs_context_for_mount(type, sb_flags); |
0c55cfc41 vfs: Allow unpriv... |
2661 |
put_filesystem(type); |
a0c9a8b8f teach vfs_get_tre... |
2662 2663 |
if (IS_ERR(fc)) return PTR_ERR(fc); |
3e1aeb00e vfs: Implement a ... |
2664 2665 2666 2667 2668 |
if (subtype) err = vfs_parse_fs_string(fc, "subtype", subtype, strlen(subtype)); if (!err && name) err = vfs_parse_fs_string(fc, "source", name, strlen(name)); |
a0c9a8b8f teach vfs_get_tre... |
2669 2670 |
if (!err) err = parse_monolithic_mount_data(fc, data); |
c3aabf078 move mount_capabl... |
2671 2672 |
if (!err && !mount_capable(fc)) err = -EPERM; |
a0c9a8b8f teach vfs_get_tre... |
2673 2674 |
if (!err) err = vfs_get_tree(fc); |
132e46084 new helper: do_ne... |
2675 2676 |
if (!err) err = do_new_mount_fc(fc, path, mnt_flags); |
8654df4e2 mnt: Refactor fs_... |
2677 |
|
a0c9a8b8f teach vfs_get_tre... |
2678 |
put_fs_context(fc); |
15f9a3f3e don't drop newmnt... |
2679 |
return err; |
1da177e4c Linux-2.6.12-rc2 |
2680 |
} |
19a167af7 Take the completi... |
2681 2682 |
int finish_automount(struct vfsmount *m, struct path *path) { |
6776db3d3 vfs: take mnt_sha... |
2683 |
struct mount *mnt = real_mount(m); |
19a167af7 Take the completi... |
2684 2685 2686 2687 |
int err; /* The new mount record should have at least 2 refs to prevent it being * expired before we get a chance to add it */ |
6776db3d3 vfs: take mnt_sha... |
2688 |
BUG_ON(mnt_get_count(mnt) < 2); |
19a167af7 Take the completi... |
2689 2690 2691 |
if (m->mnt_sb == path->mnt->mnt_sb && m->mnt_root == path->dentry) { |
b1e75df45 tidy up around fi... |
2692 2693 |
err = -ELOOP; goto fail; |
19a167af7 Take the completi... |
2694 |
} |
95bc5f25c vfs: spread struc... |
2695 |
err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE); |
b1e75df45 tidy up around fi... |
2696 2697 2698 2699 |
if (!err) return 0; fail: /* remove m from any expiration list it may be on */ |
6776db3d3 vfs: take mnt_sha... |
2700 |
if (!list_empty(&mnt->mnt_expire)) { |
97216be09 fold release_moun... |
2701 |
namespace_lock(); |
6776db3d3 vfs: take mnt_sha... |
2702 |
list_del_init(&mnt->mnt_expire); |
97216be09 fold release_moun... |
2703 |
namespace_unlock(); |
19a167af7 Take the completi... |
2704 |
} |
b1e75df45 tidy up around fi... |
2705 2706 |
mntput(m); mntput(m); |
19a167af7 Take the completi... |
2707 2708 |
return err; } |
ea5b778a8 Unexport do_add_m... |
2709 2710 2711 2712 2713 2714 2715 |
/** * mnt_set_expiry - Put a mount on an expiration list * @mnt: The mount to list. * @expiry_list: The list to add the mount to. */ void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list) { |
97216be09 fold release_moun... |
2716 |
namespace_lock(); |
ea5b778a8 Unexport do_add_m... |
2717 |
|
6776db3d3 vfs: take mnt_sha... |
2718 |
list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list); |
ea5b778a8 Unexport do_add_m... |
2719 |
|
97216be09 fold release_moun... |
2720 |
namespace_unlock(); |
ea5b778a8 Unexport do_add_m... |
2721 2722 2723 2724 |
} EXPORT_SYMBOL(mnt_set_expiry); /* |
1da177e4c Linux-2.6.12-rc2 |
2725 2726 2727 2728 2729 2730 |
* process a list of expirable mountpoints with the intent of discarding any * mountpoints that aren't in use and haven't been touched since last we came * here */ void mark_mounts_for_expiry(struct list_head *mounts) { |
761d5c38e vfs: spread struc... |
2731 |
struct mount *mnt, *next; |
1da177e4c Linux-2.6.12-rc2 |
2732 2733 2734 2735 |
LIST_HEAD(graveyard); if (list_empty(mounts)) return; |
97216be09 fold release_moun... |
2736 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
2737 |
lock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
2738 2739 2740 2741 2742 2743 2744 |
/* extract from the expiration list every vfsmount that matches the * following criteria: * - only referenced by its parent vfsmount * - still marked for expiry (marked on the last call here; marks are * cleared by mntput()) */ |
6776db3d3 vfs: take mnt_sha... |
2745 |
list_for_each_entry_safe(mnt, next, mounts, mnt_expire) { |
863d684f9 vfs: move the res... |
2746 |
if (!xchg(&mnt->mnt_expiry_mark, 1) || |
1ab597386 vfs: spread struc... |
2747 |
propagate_mount_busy(mnt, 1)) |
1da177e4c Linux-2.6.12-rc2 |
2748 |
continue; |
6776db3d3 vfs: take mnt_sha... |
2749 |
list_move(&mnt->mnt_expire, &graveyard); |
1da177e4c Linux-2.6.12-rc2 |
2750 |
} |
bcc5c7d2b [PATCH] sanitize ... |
2751 |
while (!list_empty(&graveyard)) { |
6776db3d3 vfs: take mnt_sha... |
2752 |
mnt = list_first_entry(&graveyard, struct mount, mnt_expire); |
143c8c91c vfs: mnt_ns moved... |
2753 |
touch_mnt_namespace(mnt->mnt_ns); |
e819f1521 mnt: Improve the ... |
2754 |
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
bcc5c7d2b [PATCH] sanitize ... |
2755 |
} |
719ea2fbb new helpers: lock... |
2756 |
unlock_mount_hash(); |
3ab6abee5 more conversions ... |
2757 |
namespace_unlock(); |
5528f911b VFS: Add shrink_s... |
2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 |
} EXPORT_SYMBOL_GPL(mark_mounts_for_expiry); /* * Ripoff of 'select_parent()' * * search the list of submounts for a given mountpoint, and move any * shrinkable submounts to the 'graveyard' list. */ |
692afc312 vfs: spread struc... |
2768 |
static int select_submounts(struct mount *parent, struct list_head *graveyard) |
5528f911b VFS: Add shrink_s... |
2769 |
{ |
692afc312 vfs: spread struc... |
2770 |
struct mount *this_parent = parent; |
5528f911b VFS: Add shrink_s... |
2771 2772 2773 2774 |
struct list_head *next; int found = 0; repeat: |
6b41d536f vfs: take mnt_chi... |
2775 |
next = this_parent->mnt_mounts.next; |
5528f911b VFS: Add shrink_s... |
2776 |
resume: |
6b41d536f vfs: take mnt_chi... |
2777 |
while (next != &this_parent->mnt_mounts) { |
5528f911b VFS: Add shrink_s... |
2778 |
struct list_head *tmp = next; |
6b41d536f vfs: take mnt_chi... |
2779 |
struct mount *mnt = list_entry(tmp, struct mount, mnt_child); |
5528f911b VFS: Add shrink_s... |
2780 2781 |
next = tmp->next; |
692afc312 vfs: spread struc... |
2782 |
if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE)) |
1da177e4c Linux-2.6.12-rc2 |
2783 |
continue; |
5528f911b VFS: Add shrink_s... |
2784 2785 2786 |
/* * Descend a level if the d_mounts list is non-empty. */ |
6b41d536f vfs: take mnt_chi... |
2787 |
if (!list_empty(&mnt->mnt_mounts)) { |
5528f911b VFS: Add shrink_s... |
2788 2789 2790 |
this_parent = mnt; goto repeat; } |
1da177e4c Linux-2.6.12-rc2 |
2791 |
|
1ab597386 vfs: spread struc... |
2792 |
if (!propagate_mount_busy(mnt, 1)) { |
6776db3d3 vfs: take mnt_sha... |
2793 |
list_move_tail(&mnt->mnt_expire, graveyard); |
5528f911b VFS: Add shrink_s... |
2794 2795 |
found++; } |
1da177e4c Linux-2.6.12-rc2 |
2796 |
} |
5528f911b VFS: Add shrink_s... |
2797 2798 2799 2800 |
/* * All done at this level ... ascend and resume the search */ if (this_parent != parent) { |
6b41d536f vfs: take mnt_chi... |
2801 |
next = this_parent->mnt_child.next; |
0714a5338 vfs: now it can b... |
2802 |
this_parent = this_parent->mnt_parent; |
5528f911b VFS: Add shrink_s... |
2803 2804 2805 2806 2807 2808 2809 2810 |
goto resume; } return found; } /* * process a list of expirable mountpoints with the intent of discarding any * submounts of a specific parent mountpoint |
99b7db7b8 fs: brlock vfsmou... |
2811 |
* |
48a066e72 RCU'd vfsmounts |
2812 |
* mount_lock must be held for write |
5528f911b VFS: Add shrink_s... |
2813 |
*/ |
b54b9be78 get rid of the se... |
2814 |
static void shrink_submounts(struct mount *mnt) |
5528f911b VFS: Add shrink_s... |
2815 2816 |
{ LIST_HEAD(graveyard); |
761d5c38e vfs: spread struc... |
2817 |
struct mount *m; |
5528f911b VFS: Add shrink_s... |
2818 |
|
5528f911b VFS: Add shrink_s... |
2819 |
/* extract submounts of 'mountpoint' from the expiration list */ |
c35038bec [PATCH] do shrink... |
2820 |
while (select_submounts(mnt, &graveyard)) { |
bcc5c7d2b [PATCH] sanitize ... |
2821 |
while (!list_empty(&graveyard)) { |
761d5c38e vfs: spread struc... |
2822 |
m = list_first_entry(&graveyard, struct mount, |
6776db3d3 vfs: take mnt_sha... |
2823 |
mnt_expire); |
143c8c91c vfs: mnt_ns moved... |
2824 |
touch_mnt_namespace(m->mnt_ns); |
e819f1521 mnt: Improve the ... |
2825 |
umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
bcc5c7d2b [PATCH] sanitize ... |
2826 2827 |
} } |
1da177e4c Linux-2.6.12-rc2 |
2828 |
} |
1da177e4c Linux-2.6.12-rc2 |
2829 2830 2831 2832 2833 2834 |
/* * Some copy_from_user() implementations do not return the exact number of * bytes remaining to copy on a fault. But copy_mount_options() requires that. * Note that this function differs from copy_from_user() in that it will oops * on bad values of `to', rather than returning a short copy. */ |
b58fed8b1 [PATCH] lindent f... |
2835 2836 |
static long exact_copy_from_user(void *to, const void __user * from, unsigned long n) |
1da177e4c Linux-2.6.12-rc2 |
2837 2838 2839 2840 |
{ char *t = to; const char __user *f = from; char c; |
96d4f267e Remove 'type' arg... |
2841 |
if (!access_ok(from, n)) |
1da177e4c Linux-2.6.12-rc2 |
2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 |
return n; while (n) { if (__get_user(c, f)) { memset(t, 0, n); break; } *t++ = c; f++; n--; } return n; } |
b40ef8696 saner calling con... |
2855 |
void *copy_mount_options(const void __user * data) |
1da177e4c Linux-2.6.12-rc2 |
2856 2857 |
{ int i; |
1da177e4c Linux-2.6.12-rc2 |
2858 |
unsigned long size; |
b40ef8696 saner calling con... |
2859 |
char *copy; |
b58fed8b1 [PATCH] lindent f... |
2860 |
|
1da177e4c Linux-2.6.12-rc2 |
2861 |
if (!data) |
b40ef8696 saner calling con... |
2862 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
2863 |
|
b40ef8696 saner calling con... |
2864 2865 2866 |
copy = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!copy) return ERR_PTR(-ENOMEM); |
1da177e4c Linux-2.6.12-rc2 |
2867 2868 2869 2870 2871 2872 |
/* We only care that *some* data at the address the user * gave us is valid. Just in case, we'll zero * the remainder of the page. */ /* copy_from_user cannot cross TASK_SIZE ! */ |
ed8a66b83 fs/namespace: unt... |
2873 |
size = TASK_SIZE - (unsigned long)untagged_addr(data); |
1da177e4c Linux-2.6.12-rc2 |
2874 2875 |
if (size > PAGE_SIZE) size = PAGE_SIZE; |
b40ef8696 saner calling con... |
2876 |
i = size - exact_copy_from_user(copy, data, size); |
1da177e4c Linux-2.6.12-rc2 |
2877 |
if (!i) { |
b40ef8696 saner calling con... |
2878 2879 |
kfree(copy); return ERR_PTR(-EFAULT); |
1da177e4c Linux-2.6.12-rc2 |
2880 2881 |
} if (i != PAGE_SIZE) |
b40ef8696 saner calling con... |
2882 2883 |
memset(copy + i, 0, PAGE_SIZE - i); return copy; |
1da177e4c Linux-2.6.12-rc2 |
2884 |
} |
b8850d1fa fs: namespace: su... |
2885 |
char *copy_mount_string(const void __user *data) |
eca6f534e fs: fix overflow ... |
2886 |
{ |
fbdb44013 copy_mount_string... |
2887 |
return data ? strndup_user(data, PATH_MAX) : NULL; |
eca6f534e fs: fix overflow ... |
2888 |
} |
1da177e4c Linux-2.6.12-rc2 |
2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 |
/* * Flags is a 32-bit value that allows up to 31 non-fs dependent flags to * be given to the mount() call (ie: read-only, no-dev, no-suid etc). * * data is a (void *) that can point to any structure up to * PAGE_SIZE-1 bytes, which can contain arbitrary fs-dependent * information (or be NULL). * * Pre-0.97 versions of mount() didn't have a flags word. * When the flags word was introduced its top half was required * to have the magic value 0xC0ED, and this remained so until 2.4.0-test9. * Therefore, if this magic number is present, it carries no information * and must be discarded. */ |
5e6123f34 vfs: move getname... |
2903 |
long do_mount(const char *dev_name, const char __user *dir_name, |
808d4e3cf consitify do_moun... |
2904 |
const char *type_page, unsigned long flags, void *data_page) |
1da177e4c Linux-2.6.12-rc2 |
2905 |
{ |
2d92ab3c6 [PATCH] finally g... |
2906 |
struct path path; |
e462ec50c VFS: Differentiat... |
2907 |
unsigned int mnt_flags = 0, sb_flags; |
1da177e4c Linux-2.6.12-rc2 |
2908 |
int retval = 0; |
1da177e4c Linux-2.6.12-rc2 |
2909 2910 2911 2912 2913 2914 |
/* Discard magic */ if ((flags & MS_MGC_MSK) == MS_MGC_VAL) flags &= ~MS_MGC_MSK; /* Basic sanity checks */ |
1da177e4c Linux-2.6.12-rc2 |
2915 2916 |
if (data_page) ((char *)data_page)[PAGE_SIZE - 1] = 0; |
e462ec50c VFS: Differentiat... |
2917 2918 |
if (flags & MS_NOUSER) return -EINVAL; |
a27ab9f26 LSM: Pass origina... |
2919 |
/* ... and get the mountpoint */ |
ce6595a28 kill the last use... |
2920 |
retval = user_path_at(AT_FDCWD, dir_name, LOOKUP_FOLLOW, &path); |
a27ab9f26 LSM: Pass origina... |
2921 2922 2923 2924 2925 |
if (retval) return retval; retval = security_sb_mount(dev_name, &path, type_page, flags, data_page); |
0d5cadb87 do_mount(): fix a... |
2926 2927 |
if (!retval && !may_mount()) retval = -EPERM; |
e462ec50c VFS: Differentiat... |
2928 |
if (!retval && (flags & SB_MANDLOCK) && !may_mandlock()) |
9e8925b67 locks: Allow disa... |
2929 |
retval = -EPERM; |
a27ab9f26 LSM: Pass origina... |
2930 2931 |
if (retval) goto dput_out; |
613cbe3d4 Don't set relatim... |
2932 2933 2934 |
/* Default to relatime unless overriden */ if (!(flags & MS_NOATIME)) mnt_flags |= MNT_RELATIME; |
0a1c01c94 Make relatime def... |
2935 |
|
1da177e4c Linux-2.6.12-rc2 |
2936 2937 2938 2939 2940 2941 2942 |
/* Separate the per-mountpoint flags */ if (flags & MS_NOSUID) mnt_flags |= MNT_NOSUID; if (flags & MS_NODEV) mnt_flags |= MNT_NODEV; if (flags & MS_NOEXEC) mnt_flags |= MNT_NOEXEC; |
fc33a7bb9 [PATCH] per-mount... |
2943 2944 2945 2946 |
if (flags & MS_NOATIME) mnt_flags |= MNT_NOATIME; if (flags & MS_NODIRATIME) mnt_flags |= MNT_NODIRATIME; |
d0adde574 Add a strictatime... |
2947 2948 |
if (flags & MS_STRICTATIME) mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME); |
a9e5b7328 vfs: Undo an over... |
2949 |
if (flags & MS_RDONLY) |
2e4b7fcd9 [PATCH] r/o bind ... |
2950 |
mnt_flags |= MNT_READONLY; |
fc33a7bb9 [PATCH] per-mount... |
2951 |
|
ffbc6f0ea mnt: Change the d... |
2952 2953 2954 2955 2956 2957 2958 |
/* The default atime for remount is preservation */ if ((flags & MS_REMOUNT) && ((flags & (MS_NOATIME | MS_NODIRATIME | MS_RELATIME | MS_STRICTATIME)) == 0)) { mnt_flags &= ~MNT_ATIME_MASK; mnt_flags |= path.mnt->mnt_flags & MNT_ATIME_MASK; } |
e462ec50c VFS: Differentiat... |
2959 2960 2961 2962 2963 |
sb_flags = flags & (SB_RDONLY | SB_SYNCHRONOUS | SB_MANDLOCK | SB_DIRSYNC | SB_SILENT | |
917086ff2 vfs: fix mounting... |
2964 |
SB_POSIXACL | |
d7ee94694 VFS: Handle lazyt... |
2965 |
SB_LAZYTIME | |
917086ff2 vfs: fix mounting... |
2966 |
SB_I_VERSION); |
1da177e4c Linux-2.6.12-rc2 |
2967 |
|
43f5e655e vfs: Separate cha... |
2968 2969 2970 |
if ((flags & (MS_REMOUNT | MS_BIND)) == (MS_REMOUNT | MS_BIND)) retval = do_reconfigure_mnt(&path, mnt_flags); else if (flags & MS_REMOUNT) |
e462ec50c VFS: Differentiat... |
2971 |
retval = do_remount(&path, flags, sb_flags, mnt_flags, |
1da177e4c Linux-2.6.12-rc2 |
2972 2973 |
data_page); else if (flags & MS_BIND) |
2d92ab3c6 [PATCH] finally g... |
2974 |
retval = do_loopback(&path, dev_name, flags & MS_REC); |
9676f0c63 [PATCH] unbindabl... |
2975 |
else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) |
2d92ab3c6 [PATCH] finally g... |
2976 |
retval = do_change_type(&path, flags); |
1da177e4c Linux-2.6.12-rc2 |
2977 |
else if (flags & MS_MOVE) |
2db154b3e vfs: syscall: Add... |
2978 |
retval = do_move_mount_old(&path, dev_name); |
1da177e4c Linux-2.6.12-rc2 |
2979 |
else |
e462ec50c VFS: Differentiat... |
2980 |
retval = do_new_mount(&path, type_page, sb_flags, mnt_flags, |
1da177e4c Linux-2.6.12-rc2 |
2981 2982 |
dev_name, data_page); dput_out: |
2d92ab3c6 [PATCH] finally g... |
2983 |
path_put(&path); |
1da177e4c Linux-2.6.12-rc2 |
2984 2985 |
return retval; } |
537f7ccb3 mntns: Add a limi... |
2986 2987 2988 2989 2990 2991 2992 2993 2994 |
static struct ucounts *inc_mnt_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_MNT_NAMESPACES); } static void dec_mnt_namespaces(struct ucounts *ucounts) { dec_ucount(ucounts, UCOUNT_MNT_NAMESPACES); } |
771b13716 vfs: Add a user n... |
2995 2996 |
static void free_mnt_ns(struct mnt_namespace *ns) { |
74e831221 saner handling of... |
2997 2998 |
if (!is_anon_ns(ns)) ns_free_inum(&ns->ns); |
537f7ccb3 mntns: Add a limi... |
2999 |
dec_mnt_namespaces(ns->ucounts); |
771b13716 vfs: Add a user n... |
3000 3001 3002 |
put_user_ns(ns->user_ns); kfree(ns); } |
8823c079b vfs: Add setns su... |
3003 3004 3005 3006 3007 3008 3009 3010 |
/* * Assign a sequence number so we can detect when we attempt to bind * mount a reference to an older mount namespace into the current * mount namespace, preventing reference counting loops. A 64bit * number incrementing at 10Ghz will take 12,427 years to wrap which * is effectively never, so we can ignore the possibility. */ static atomic64_t mnt_ns_seq = ATOMIC64_INIT(1); |
74e831221 saner handling of... |
3011 |
static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool anon) |
cf8d2c11c VFS: Add VFS help... |
3012 3013 |
{ struct mnt_namespace *new_ns; |
537f7ccb3 mntns: Add a limi... |
3014 |
struct ucounts *ucounts; |
98f842e67 proc: Usable inod... |
3015 |
int ret; |
cf8d2c11c VFS: Add VFS help... |
3016 |
|
537f7ccb3 mntns: Add a limi... |
3017 3018 |
ucounts = inc_mnt_namespaces(user_ns); if (!ucounts) |
df75e7748 userns: When the ... |
3019 |
return ERR_PTR(-ENOSPC); |
537f7ccb3 mntns: Add a limi... |
3020 |
|
74e831221 saner handling of... |
3021 |
new_ns = kzalloc(sizeof(struct mnt_namespace), GFP_KERNEL); |
537f7ccb3 mntns: Add a limi... |
3022 3023 |
if (!new_ns) { dec_mnt_namespaces(ucounts); |
cf8d2c11c VFS: Add VFS help... |
3024 |
return ERR_PTR(-ENOMEM); |
537f7ccb3 mntns: Add a limi... |
3025 |
} |
74e831221 saner handling of... |
3026 3027 3028 3029 3030 3031 3032 |
if (!anon) { ret = ns_alloc_inum(&new_ns->ns); if (ret) { kfree(new_ns); dec_mnt_namespaces(ucounts); return ERR_PTR(ret); } |
98f842e67 proc: Usable inod... |
3033 |
} |
33c429405 copy address of p... |
3034 |
new_ns->ns.ops = &mntns_operations; |
74e831221 saner handling of... |
3035 3036 |
if (!anon) new_ns->seq = atomic64_add_return(1, &mnt_ns_seq); |
cf8d2c11c VFS: Add VFS help... |
3037 |
atomic_set(&new_ns->count, 1); |
cf8d2c11c VFS: Add VFS help... |
3038 3039 |
INIT_LIST_HEAD(&new_ns->list); init_waitqueue_head(&new_ns->poll); |
771b13716 vfs: Add a user n... |
3040 |
new_ns->user_ns = get_user_ns(user_ns); |
537f7ccb3 mntns: Add a limi... |
3041 |
new_ns->ucounts = ucounts; |
cf8d2c11c VFS: Add VFS help... |
3042 3043 |
return new_ns; } |
0766f788e latent_entropy: M... |
3044 |
__latent_entropy |
9559f6891 fold dup_mnt_ns()... |
3045 3046 |
struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, struct user_namespace *user_ns, struct fs_struct *new_fs) |
1da177e4c Linux-2.6.12-rc2 |
3047 |
{ |
6b3286ed1 [PATCH] rename st... |
3048 |
struct mnt_namespace *new_ns; |
7f2da1e7d [PATCH] kill altroot |
3049 |
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL; |
315fc83e5 vfs: spread struc... |
3050 |
struct mount *p, *q; |
9559f6891 fold dup_mnt_ns()... |
3051 |
struct mount *old; |
cb338d06e vfs: spread struc... |
3052 |
struct mount *new; |
7a472ef4b vfs: Only support... |
3053 |
int copy_flags; |
1da177e4c Linux-2.6.12-rc2 |
3054 |
|
9559f6891 fold dup_mnt_ns()... |
3055 3056 3057 3058 3059 3060 3061 3062 |
BUG_ON(!ns); if (likely(!(flags & CLONE_NEWNS))) { get_mnt_ns(ns); return ns; } old = ns->root; |
74e831221 saner handling of... |
3063 |
new_ns = alloc_mnt_ns(user_ns, false); |
cf8d2c11c VFS: Add VFS help... |
3064 3065 |
if (IS_ERR(new_ns)) return new_ns; |
1da177e4c Linux-2.6.12-rc2 |
3066 |
|
97216be09 fold release_moun... |
3067 |
namespace_lock(); |
1da177e4c Linux-2.6.12-rc2 |
3068 |
/* First pass: copy the tree topology */ |
4ce5d2b1a vfs: Don't copy m... |
3069 |
copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE; |
9559f6891 fold dup_mnt_ns()... |
3070 |
if (user_ns != ns->user_ns) |
3bd045cc9 separate copying ... |
3071 |
copy_flags |= CL_SHARED_TO_SLAVE; |
7a472ef4b vfs: Only support... |
3072 |
new = copy_tree(old, old->mnt.mnt_root, copy_flags); |
be34d1a3b VFS: Make clone_m... |
3073 |
if (IS_ERR(new)) { |
328e6d901 switch unlock_mou... |
3074 |
namespace_unlock(); |
771b13716 vfs: Add a user n... |
3075 |
free_mnt_ns(new_ns); |
be34d1a3b VFS: Make clone_m... |
3076 |
return ERR_CAST(new); |
1da177e4c Linux-2.6.12-rc2 |
3077 |
} |
3bd045cc9 separate copying ... |
3078 3079 3080 3081 3082 |
if (user_ns != ns->user_ns) { lock_mount_hash(); lock_mnt_tree(new); unlock_mount_hash(); } |
be08d6d26 switch mnt_namesp... |
3083 |
new_ns->root = new; |
1a4eeaf2a vfs: move mnt_lis... |
3084 |
list_add_tail(&new_ns->list, &new->mnt_list); |
1da177e4c Linux-2.6.12-rc2 |
3085 3086 3087 3088 3089 3090 |
/* * Second pass: switch the tsk->fs->* elements and mark new vfsmounts * as belonging to new namespace. We have already acquired a private * fs_struct, so tsk->fs->lock is not needed. */ |
909b0a88e vfs: spread struc... |
3091 |
p = old; |
cb338d06e vfs: spread struc... |
3092 |
q = new; |
1da177e4c Linux-2.6.12-rc2 |
3093 |
while (p) { |
143c8c91c vfs: mnt_ns moved... |
3094 |
q->mnt_ns = new_ns; |
d29216842 mnt: Add a per mo... |
3095 |
new_ns->mounts++; |
9559f6891 fold dup_mnt_ns()... |
3096 3097 3098 |
if (new_fs) { if (&p->mnt == new_fs->root.mnt) { new_fs->root.mnt = mntget(&q->mnt); |
315fc83e5 vfs: spread struc... |
3099 |
rootmnt = &p->mnt; |
1da177e4c Linux-2.6.12-rc2 |
3100 |
} |
9559f6891 fold dup_mnt_ns()... |
3101 3102 |
if (&p->mnt == new_fs->pwd.mnt) { new_fs->pwd.mnt = mntget(&q->mnt); |
315fc83e5 vfs: spread struc... |
3103 |
pwdmnt = &p->mnt; |
1da177e4c Linux-2.6.12-rc2 |
3104 |
} |
1da177e4c Linux-2.6.12-rc2 |
3105 |
} |
909b0a88e vfs: spread struc... |
3106 3107 |
p = next_mnt(p, old); q = next_mnt(q, new); |
4ce5d2b1a vfs: Don't copy m... |
3108 3109 3110 3111 |
if (!q) break; while (p->mnt.mnt_root != q->mnt.mnt_root) p = next_mnt(p, old); |
1da177e4c Linux-2.6.12-rc2 |
3112 |
} |
328e6d901 switch unlock_mou... |
3113 |
namespace_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
3114 |
|
1da177e4c Linux-2.6.12-rc2 |
3115 |
if (rootmnt) |
f03c65993 sanitize vfsmount... |
3116 |
mntput(rootmnt); |
1da177e4c Linux-2.6.12-rc2 |
3117 |
if (pwdmnt) |
f03c65993 sanitize vfsmount... |
3118 |
mntput(pwdmnt); |
1da177e4c Linux-2.6.12-rc2 |
3119 |
|
741a29513 [PATCH] unshare s... |
3120 |
return new_ns; |
1da177e4c Linux-2.6.12-rc2 |
3121 |
} |
74e831221 saner handling of... |
3122 |
struct dentry *mount_subtree(struct vfsmount *m, const char *name) |
ea441d110 new helper: mount... |
3123 |
{ |
74e831221 saner handling of... |
3124 |
struct mount *mnt = real_mount(m); |
ea441d110 new helper: mount... |
3125 |
struct mnt_namespace *ns; |
d31da0f0b mount_subtree() p... |
3126 |
struct super_block *s; |
ea441d110 new helper: mount... |
3127 3128 |
struct path path; int err; |
74e831221 saner handling of... |
3129 3130 3131 |
ns = alloc_mnt_ns(&init_user_ns, true); if (IS_ERR(ns)) { mntput(m); |
ea441d110 new helper: mount... |
3132 |
return ERR_CAST(ns); |
74e831221 saner handling of... |
3133 3134 3135 3136 3137 |
} mnt->mnt_ns = ns; ns->root = mnt; ns->mounts++; list_add(&mnt->mnt_list, &ns->list); |
ea441d110 new helper: mount... |
3138 |
|
74e831221 saner handling of... |
3139 |
err = vfs_path_lookup(m->mnt_root, m, |
ea441d110 new helper: mount... |
3140 3141 3142 3143 3144 3145 3146 3147 |
name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path); put_mnt_ns(ns); if (err) return ERR_PTR(err); /* trade a vfsmount reference for active sb one */ |
d31da0f0b mount_subtree() p... |
3148 3149 |
s = path.mnt->mnt_sb; atomic_inc(&s->s_active); |
ea441d110 new helper: mount... |
3150 3151 |
mntput(path.mnt); /* lock the sucker */ |
d31da0f0b mount_subtree() p... |
3152 |
down_write(&s->s_umount); |
ea441d110 new helper: mount... |
3153 3154 3155 3156 |
/* ... and return the root of (sub)tree on it */ return path.dentry; } EXPORT_SYMBOL(mount_subtree); |
33488845f constify ksys_mou... |
3157 3158 |
int ksys_mount(const char __user *dev_name, const char __user *dir_name, const char __user *type, unsigned long flags, void __user *data) |
1da177e4c Linux-2.6.12-rc2 |
3159 |
{ |
eca6f534e fs: fix overflow ... |
3160 3161 |
int ret; char *kernel_type; |
eca6f534e fs: fix overflow ... |
3162 |
char *kernel_dev; |
b40ef8696 saner calling con... |
3163 |
void *options; |
1da177e4c Linux-2.6.12-rc2 |
3164 |
|
b8850d1fa fs: namespace: su... |
3165 3166 3167 |
kernel_type = copy_mount_string(type); ret = PTR_ERR(kernel_type); if (IS_ERR(kernel_type)) |
eca6f534e fs: fix overflow ... |
3168 |
goto out_type; |
1da177e4c Linux-2.6.12-rc2 |
3169 |
|
b8850d1fa fs: namespace: su... |
3170 3171 3172 |
kernel_dev = copy_mount_string(dev_name); ret = PTR_ERR(kernel_dev); if (IS_ERR(kernel_dev)) |
eca6f534e fs: fix overflow ... |
3173 |
goto out_dev; |
1da177e4c Linux-2.6.12-rc2 |
3174 |
|
b40ef8696 saner calling con... |
3175 3176 3177 |
options = copy_mount_options(data); ret = PTR_ERR(options); if (IS_ERR(options)) |
eca6f534e fs: fix overflow ... |
3178 |
goto out_data; |
1da177e4c Linux-2.6.12-rc2 |
3179 |
|
b40ef8696 saner calling con... |
3180 |
ret = do_mount(kernel_dev, dir_name, kernel_type, flags, options); |
1da177e4c Linux-2.6.12-rc2 |
3181 |
|
b40ef8696 saner calling con... |
3182 |
kfree(options); |
eca6f534e fs: fix overflow ... |
3183 3184 3185 |
out_data: kfree(kernel_dev); out_dev: |
eca6f534e fs: fix overflow ... |
3186 3187 3188 |
kfree(kernel_type); out_type: return ret; |
1da177e4c Linux-2.6.12-rc2 |
3189 |
} |
312db1aa1 fs: add ksys_moun... |
3190 3191 3192 3193 3194 |
SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name, char __user *, type, unsigned long, flags, void __user *, data) { return ksys_mount(dev_name, dir_name, type, flags, data); } |
1da177e4c Linux-2.6.12-rc2 |
3195 |
/* |
93766fbd2 vfs: syscall: Add... |
3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 |
* Create a kernel mount representation for a new, prepared superblock * (specified by fs_fd) and attach to an open_tree-like file descriptor. */ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags, unsigned int, attr_flags) { struct mnt_namespace *ns; struct fs_context *fc; struct file *file; struct path newmount; struct mount *mnt; struct fd f; unsigned int mnt_flags = 0; long ret; if (!may_mount()) return -EPERM; if ((flags & ~(FSMOUNT_CLOEXEC)) != 0) return -EINVAL; if (attr_flags & ~(MOUNT_ATTR_RDONLY | MOUNT_ATTR_NOSUID | MOUNT_ATTR_NODEV | MOUNT_ATTR_NOEXEC | MOUNT_ATTR__ATIME | MOUNT_ATTR_NODIRATIME)) return -EINVAL; if (attr_flags & MOUNT_ATTR_RDONLY) mnt_flags |= MNT_READONLY; if (attr_flags & MOUNT_ATTR_NOSUID) mnt_flags |= MNT_NOSUID; if (attr_flags & MOUNT_ATTR_NODEV) mnt_flags |= MNT_NODEV; if (attr_flags & MOUNT_ATTR_NOEXEC) mnt_flags |= MNT_NOEXEC; if (attr_flags & MOUNT_ATTR_NODIRATIME) mnt_flags |= MNT_NODIRATIME; switch (attr_flags & MOUNT_ATTR__ATIME) { case MOUNT_ATTR_STRICTATIME: break; case MOUNT_ATTR_NOATIME: mnt_flags |= MNT_NOATIME; break; case MOUNT_ATTR_RELATIME: mnt_flags |= MNT_RELATIME; break; default: return -EINVAL; } f = fdget(fs_fd); if (!f.file) return -EBADF; ret = -EINVAL; if (f.file->f_op != &fscontext_fops) goto err_fsfd; fc = f.file->private_data; ret = mutex_lock_interruptible(&fc->uapi_mutex); if (ret < 0) goto err_fsfd; /* There must be a valid superblock or we can't mount it */ ret = -EINVAL; if (!fc->root) goto err_unlock; ret = -EPERM; if (mount_too_revealing(fc->root->d_sb, &mnt_flags)) { pr_warn("VFS: Mount too revealing "); goto err_unlock; } ret = -EBUSY; if (fc->phase != FS_CONTEXT_AWAITING_MOUNT) goto err_unlock; ret = -EPERM; if ((fc->sb_flags & SB_MANDLOCK) && !may_mandlock()) goto err_unlock; newmount.mnt = vfs_create_mount(fc); if (IS_ERR(newmount.mnt)) { ret = PTR_ERR(newmount.mnt); goto err_unlock; } newmount.dentry = dget(fc->root); newmount.mnt->mnt_flags = mnt_flags; /* We've done the mount bit - now move the file context into more or * less the same state as if we'd done an fspick(). We don't want to * do any memory allocation or anything like that at this point as we * don't want to have to handle any errors incurred. */ vfs_clean_context(fc); ns = alloc_mnt_ns(current->nsproxy->mnt_ns->user_ns, true); if (IS_ERR(ns)) { ret = PTR_ERR(ns); goto err_path; } mnt = real_mount(newmount.mnt); mnt->mnt_ns = ns; ns->root = mnt; ns->mounts = 1; list_add(&mnt->mnt_list, &ns->list); |
1b0b9cc8d vfs: fsmount: add... |
3308 |
mntget(newmount.mnt); |
93766fbd2 vfs: syscall: Add... |
3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 |
/* Attach to an apparent O_PATH fd with a note that we need to unmount * it, not just simply put it. */ file = dentry_open(&newmount, O_PATH, fc->cred); if (IS_ERR(file)) { dissolve_on_fput(newmount.mnt); ret = PTR_ERR(file); goto err_path; } file->f_mode |= FMODE_NEED_UNMOUNT; ret = get_unused_fd_flags((flags & FSMOUNT_CLOEXEC) ? O_CLOEXEC : 0); if (ret >= 0) fd_install(ret, file); else fput(file); err_path: path_put(&newmount); err_unlock: mutex_unlock(&fc->uapi_mutex); err_fsfd: fdput(f); return ret; } /* * Move a mount from one place to another. In combination with * fsopen()/fsmount() this is used to install a new mount and in combination * with open_tree(OPEN_TREE_CLONE [| AT_RECURSIVE]) it can be used to copy * a mount subtree. |
2db154b3e vfs: syscall: Add... |
3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 |
* * Note the flags value is a combination of MOVE_MOUNT_* flags. */ SYSCALL_DEFINE5(move_mount, int, from_dfd, const char *, from_pathname, int, to_dfd, const char *, to_pathname, unsigned int, flags) { struct path from_path, to_path; unsigned int lflags; int ret = 0; if (!may_mount()) return -EPERM; if (flags & ~MOVE_MOUNT__MASK) return -EINVAL; /* If someone gives a pathname, they aren't permitted to move * from an fd that requires unmount as we can't get at the flag * to clear it afterwards. */ lflags = 0; if (flags & MOVE_MOUNT_F_SYMLINKS) lflags |= LOOKUP_FOLLOW; if (flags & MOVE_MOUNT_F_AUTOMOUNTS) lflags |= LOOKUP_AUTOMOUNT; if (flags & MOVE_MOUNT_F_EMPTY_PATH) lflags |= LOOKUP_EMPTY; ret = user_path_at(from_dfd, from_pathname, lflags, &from_path); if (ret < 0) return ret; lflags = 0; if (flags & MOVE_MOUNT_T_SYMLINKS) lflags |= LOOKUP_FOLLOW; if (flags & MOVE_MOUNT_T_AUTOMOUNTS) lflags |= LOOKUP_AUTOMOUNT; if (flags & MOVE_MOUNT_T_EMPTY_PATH) lflags |= LOOKUP_EMPTY; ret = user_path_at(to_dfd, to_pathname, lflags, &to_path); if (ret < 0) goto out_from; ret = security_move_mount(&from_path, &to_path); if (ret < 0) goto out_to; ret = do_move_mount(&from_path, &to_path); out_to: path_put(&to_path); out_from: path_put(&from_path); return ret; } /* |
afac7cba7 vfs: more mnt_par... |
3395 3396 |
* Return true if path is reachable from root * |
48a066e72 RCU'd vfsmounts |
3397 |
* namespace_sem or mount_lock is held |
afac7cba7 vfs: more mnt_par... |
3398 |
*/ |
643822b41 vfs: spread struc... |
3399 |
bool is_path_reachable(struct mount *mnt, struct dentry *dentry, |
afac7cba7 vfs: more mnt_par... |
3400 3401 |
const struct path *root) { |
643822b41 vfs: spread struc... |
3402 |
while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) { |
a73324da7 vfs: move mnt_mou... |
3403 |
dentry = mnt->mnt_mountpoint; |
0714a5338 vfs: now it can b... |
3404 |
mnt = mnt->mnt_parent; |
afac7cba7 vfs: more mnt_par... |
3405 |
} |
643822b41 vfs: spread struc... |
3406 |
return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry); |
afac7cba7 vfs: more mnt_par... |
3407 |
} |
640eb7e7b fs: Constify path... |
3408 |
bool path_is_under(const struct path *path1, const struct path *path2) |
afac7cba7 vfs: more mnt_par... |
3409 |
{ |
25ab4c9b1 fs/namespace.c: p... |
3410 |
bool res; |
48a066e72 RCU'd vfsmounts |
3411 |
read_seqlock_excl(&mount_lock); |
643822b41 vfs: spread struc... |
3412 |
res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2); |
48a066e72 RCU'd vfsmounts |
3413 |
read_sequnlock_excl(&mount_lock); |
afac7cba7 vfs: more mnt_par... |
3414 3415 3416 3417 3418 |
return res; } EXPORT_SYMBOL(path_is_under); /* |
1da177e4c Linux-2.6.12-rc2 |
3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 |
* pivot_root Semantics: * Moves the root file system of the current process to the directory put_old, * makes new_root as the new root file system of the current process, and sets * root/cwd of all processes which had them on the current root to new_root. * * Restrictions: * The new_root and put_old must be directories, and must not be on the * same file system as the current process root. The put_old must be * underneath new_root, i.e. adding a non-zero number of /.. to the string * pointed to by put_old must yield the same directory as new_root. No other * file system may be mounted on put_old. After all, new_root is a mountpoint. * |
4a0d11fae [PATCH] pivot_roo... |
3431 3432 3433 3434 |
* Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem. * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives * in this situation. * |
1da177e4c Linux-2.6.12-rc2 |
3435 3436 3437 3438 3439 3440 3441 3442 |
* Notes: * - we don't move root/cwd if they are not at the root (reason: if something * cared enough to change them, it's probably wrong to force them elsewhere) * - it's okay to pick a root that isn't the root of a file system, e.g. * /nfs/my_root where /nfs is the mount point. It must be a mountpoint, * though, so you may need to say mount --bind /nfs/my_root /nfs/my_root * first. */ |
3480b2574 [CVE-2009-0029] S... |
3443 3444 |
SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, const char __user *, put_old) |
1da177e4c Linux-2.6.12-rc2 |
3445 |
{ |
2763d1191 get rid of detach... |
3446 3447 |
struct path new, old, root; struct mount *new_mnt, *root_mnt, *old_mnt, *root_parent, *ex_parent; |
84d17192d get rid of full-h... |
3448 |
struct mountpoint *old_mp, *root_mp; |
1da177e4c Linux-2.6.12-rc2 |
3449 |
int error; |
9b40bc90a get rid of unprot... |
3450 |
if (!may_mount()) |
1da177e4c Linux-2.6.12-rc2 |
3451 |
return -EPERM; |
ce6595a28 kill the last use... |
3452 3453 |
error = user_path_at(AT_FDCWD, new_root, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &new); |
1da177e4c Linux-2.6.12-rc2 |
3454 3455 |
if (error) goto out0; |
1da177e4c Linux-2.6.12-rc2 |
3456 |
|
ce6595a28 kill the last use... |
3457 3458 |
error = user_path_at(AT_FDCWD, put_old, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old); |
1da177e4c Linux-2.6.12-rc2 |
3459 3460 |
if (error) goto out1; |
2d8f30380 [PATCH] sanitize ... |
3461 |
error = security_sb_pivotroot(&old, &new); |
b12cea919 change the lockin... |
3462 3463 |
if (error) goto out2; |
1da177e4c Linux-2.6.12-rc2 |
3464 |
|
f7ad3c6be vfs: add helpers ... |
3465 |
get_fs_root(current->fs, &root); |
84d17192d get rid of full-h... |
3466 3467 3468 |
old_mp = lock_mount(&old); error = PTR_ERR(old_mp); if (IS_ERR(old_mp)) |
b12cea919 change the lockin... |
3469 |
goto out3; |
1da177e4c Linux-2.6.12-rc2 |
3470 |
error = -EINVAL; |
419148da6 vfs: spread struc... |
3471 3472 |
new_mnt = real_mount(new.mnt); root_mnt = real_mount(root.mnt); |
84d17192d get rid of full-h... |
3473 |
old_mnt = real_mount(old.mnt); |
2763d1191 get rid of detach... |
3474 3475 |
ex_parent = new_mnt->mnt_parent; root_parent = root_mnt->mnt_parent; |
84d17192d get rid of full-h... |
3476 |
if (IS_MNT_SHARED(old_mnt) || |
2763d1191 get rid of detach... |
3477 3478 |
IS_MNT_SHARED(ex_parent) || IS_MNT_SHARED(root_parent)) |
b12cea919 change the lockin... |
3479 |
goto out4; |
143c8c91c vfs: mnt_ns moved... |
3480 |
if (!check_mnt(root_mnt) || !check_mnt(new_mnt)) |
b12cea919 change the lockin... |
3481 |
goto out4; |
5ff9d8a65 vfs: Lock in plac... |
3482 3483 |
if (new_mnt->mnt.mnt_flags & MNT_LOCKED) goto out4; |
1da177e4c Linux-2.6.12-rc2 |
3484 |
error = -ENOENT; |
f3da392e9 dcache: extrace a... |
3485 |
if (d_unlinked(new.dentry)) |
b12cea919 change the lockin... |
3486 |
goto out4; |
1da177e4c Linux-2.6.12-rc2 |
3487 |
error = -EBUSY; |
84d17192d get rid of full-h... |
3488 |
if (new_mnt == root_mnt || old_mnt == root_mnt) |
b12cea919 change the lockin... |
3489 |
goto out4; /* loop, on the same file system */ |
1da177e4c Linux-2.6.12-rc2 |
3490 |
error = -EINVAL; |
8c3ee42e8 [PATCH] get rid o... |
3491 |
if (root.mnt->mnt_root != root.dentry) |
b12cea919 change the lockin... |
3492 |
goto out4; /* not a mountpoint */ |
676da58df vfs: spread struc... |
3493 |
if (!mnt_has_parent(root_mnt)) |
b12cea919 change the lockin... |
3494 |
goto out4; /* not attached */ |
2d8f30380 [PATCH] sanitize ... |
3495 |
if (new.mnt->mnt_root != new.dentry) |
b12cea919 change the lockin... |
3496 |
goto out4; /* not a mountpoint */ |
676da58df vfs: spread struc... |
3497 |
if (!mnt_has_parent(new_mnt)) |
b12cea919 change the lockin... |
3498 |
goto out4; /* not attached */ |
4ac913785 Embed a struct pa... |
3499 |
/* make sure we can reach put_old from new_root */ |
84d17192d get rid of full-h... |
3500 |
if (!is_path_reachable(old_mnt, old.dentry, &new)) |
b12cea919 change the lockin... |
3501 |
goto out4; |
0d0826019 mnt: Prevent pivo... |
3502 3503 3504 |
/* make certain new is below the root */ if (!is_path_reachable(new_mnt, new.dentry, &root)) goto out4; |
719ea2fbb new helpers: lock... |
3505 |
lock_mount_hash(); |
2763d1191 get rid of detach... |
3506 3507 |
umount_mnt(new_mnt); root_mp = unhash_mnt(root_mnt); /* we'll need its mountpoint */ |
5ff9d8a65 vfs: Lock in plac... |
3508 3509 3510 3511 |
if (root_mnt->mnt.mnt_flags & MNT_LOCKED) { new_mnt->mnt.mnt_flags |= MNT_LOCKED; root_mnt->mnt.mnt_flags &= ~MNT_LOCKED; } |
4ac913785 Embed a struct pa... |
3512 |
/* mount old root on put_old */ |
84d17192d get rid of full-h... |
3513 |
attach_mnt(root_mnt, old_mnt, old_mp); |
4ac913785 Embed a struct pa... |
3514 |
/* mount new_root on / */ |
2763d1191 get rid of detach... |
3515 3516 |
attach_mnt(new_mnt, root_parent, root_mp); mnt_add_count(root_parent, -1); |
6b3286ed1 [PATCH] rename st... |
3517 |
touch_mnt_namespace(current->nsproxy->mnt_ns); |
4fed655c4 mnt: Clear mnt_ex... |
3518 3519 |
/* A moved mount should not expire automatically */ list_del_init(&new_mnt->mnt_expire); |
3895dbf89 mnt: Protect the ... |
3520 |
put_mountpoint(root_mp); |
719ea2fbb new helpers: lock... |
3521 |
unlock_mount_hash(); |
2d8f30380 [PATCH] sanitize ... |
3522 |
chroot_fs_refs(&root, &new); |
1da177e4c Linux-2.6.12-rc2 |
3523 |
error = 0; |
b12cea919 change the lockin... |
3524 |
out4: |
84d17192d get rid of full-h... |
3525 |
unlock_mount(old_mp); |
2763d1191 get rid of detach... |
3526 3527 |
if (!error) mntput_no_expire(ex_parent); |
b12cea919 change the lockin... |
3528 |
out3: |
8c3ee42e8 [PATCH] get rid o... |
3529 |
path_put(&root); |
b12cea919 change the lockin... |
3530 |
out2: |
2d8f30380 [PATCH] sanitize ... |
3531 |
path_put(&old); |
1da177e4c Linux-2.6.12-rc2 |
3532 |
out1: |
2d8f30380 [PATCH] sanitize ... |
3533 |
path_put(&new); |
1da177e4c Linux-2.6.12-rc2 |
3534 |
out0: |
1da177e4c Linux-2.6.12-rc2 |
3535 |
return error; |
1da177e4c Linux-2.6.12-rc2 |
3536 3537 3538 3539 3540 |
} static void __init init_mount_tree(void) { struct vfsmount *mnt; |
74e831221 saner handling of... |
3541 |
struct mount *m; |
6b3286ed1 [PATCH] rename st... |
3542 |
struct mnt_namespace *ns; |
ac748a09f Make set_fs_{root... |
3543 |
struct path root; |
1da177e4c Linux-2.6.12-rc2 |
3544 |
|
fd3e007f6 don't bother with... |
3545 |
mnt = vfs_kern_mount(&rootfs_fs_type, 0, "rootfs", NULL); |
1da177e4c Linux-2.6.12-rc2 |
3546 3547 |
if (IS_ERR(mnt)) panic("Can't create rootfs"); |
b3e19d924 fs: scale mntget/... |
3548 |
|
74e831221 saner handling of... |
3549 |
ns = alloc_mnt_ns(&init_user_ns, false); |
3b22edc57 VFS: Switch init_... |
3550 |
if (IS_ERR(ns)) |
1da177e4c Linux-2.6.12-rc2 |
3551 |
panic("Can't allocate initial namespace"); |
74e831221 saner handling of... |
3552 3553 3554 3555 3556 |
m = real_mount(mnt); m->mnt_ns = ns; ns->root = m; ns->mounts = 1; list_add(&m->mnt_list, &ns->list); |
6b3286ed1 [PATCH] rename st... |
3557 3558 |
init_task.nsproxy->mnt_ns = ns; get_mnt_ns(ns); |
be08d6d26 switch mnt_namesp... |
3559 3560 |
root.mnt = mnt; root.dentry = mnt->mnt_root; |
da362b09e umount: Do not al... |
3561 |
mnt->mnt_flags |= MNT_LOCKED; |
ac748a09f Make set_fs_{root... |
3562 3563 3564 |
set_fs_pwd(current->fs, &root); set_fs_root(current->fs, &root); |
1da177e4c Linux-2.6.12-rc2 |
3565 |
} |
74bf17cff fs: remove the un... |
3566 |
void __init mnt_init(void) |
1da177e4c Linux-2.6.12-rc2 |
3567 |
{ |
15a67dd8c [PATCH] fs/namesp... |
3568 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
3569 |
|
7d6fec45a vfs: start hiding... |
3570 |
mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount), |
20c2df83d mm: Remove slab d... |
3571 |
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
3572 |
|
0818bf27c resizable namespa... |
3573 |
mount_hashtable = alloc_large_system_hash("Mount-cache", |
38129a13e switch mnt_hash t... |
3574 |
sizeof(struct hlist_head), |
0818bf27c resizable namespa... |
3575 |
mhash_entries, 19, |
3d375d785 mm: update caller... |
3576 |
HASH_ZERO, |
0818bf27c resizable namespa... |
3577 3578 3579 3580 |
&m_hash_shift, &m_hash_mask, 0, 0); mountpoint_hashtable = alloc_large_system_hash("Mountpoint-cache", sizeof(struct hlist_head), mphash_entries, 19, |
3d375d785 mm: update caller... |
3581 |
HASH_ZERO, |
0818bf27c resizable namespa... |
3582 |
&mp_hash_shift, &mp_hash_mask, 0, 0); |
1da177e4c Linux-2.6.12-rc2 |
3583 |
|
84d17192d get rid of full-h... |
3584 |
if (!mount_hashtable || !mountpoint_hashtable) |
1da177e4c Linux-2.6.12-rc2 |
3585 3586 |
panic("Failed to allocate mount hash table "); |
4b93dc9b1 sysfs, kernfs: pr... |
3587 |
kernfs_init(); |
15a67dd8c [PATCH] fs/namesp... |
3588 3589 3590 3591 |
err = sysfs_init(); if (err) printk(KERN_WARNING "%s: sysfs_init error: %d ", |
8e24eea72 fs: replace remai... |
3592 |
__func__, err); |
00d266662 kobject: convert ... |
3593 3594 |
fs_kobj = kobject_create_and_add("fs", NULL); if (!fs_kobj) |
8e24eea72 fs: replace remai... |
3595 3596 |
printk(KERN_WARNING "%s: kobj create error ", __func__); |
037f11b47 mnt_init(): call ... |
3597 |
shmem_init(); |
1da177e4c Linux-2.6.12-rc2 |
3598 3599 3600 |
init_rootfs(); init_mount_tree(); } |
616511d03 VFS: Uninline the... |
3601 |
void put_mnt_ns(struct mnt_namespace *ns) |
1da177e4c Linux-2.6.12-rc2 |
3602 |
{ |
d498b25a4 get rid of useles... |
3603 |
if (!atomic_dec_and_test(&ns->count)) |
616511d03 VFS: Uninline the... |
3604 |
return; |
7b00ed6fe put_mnt_ns(): use... |
3605 |
drop_collected_mounts(&ns->root->mnt); |
771b13716 vfs: Add a user n... |
3606 |
free_mnt_ns(ns); |
1da177e4c Linux-2.6.12-rc2 |
3607 |
} |
9d412a43c vfs: split off vf... |
3608 |
|
d911b4585 vfs: Remove kern_... |
3609 |
struct vfsmount *kern_mount(struct file_system_type *type) |
9d412a43c vfs: split off vf... |
3610 |
{ |
423e0ab08 VFS : mount lock ... |
3611 |
struct vfsmount *mnt; |
d911b4585 vfs: Remove kern_... |
3612 |
mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, NULL); |
423e0ab08 VFS : mount lock ... |
3613 3614 3615 3616 3617 |
if (!IS_ERR(mnt)) { /* * it is a longterm mount, don't release mnt until * we unmount before file sys is unregistered */ |
f7a99c5b7 get rid of ->mnt_... |
3618 |
real_mount(mnt)->mnt_ns = MNT_NS_INTERNAL; |
423e0ab08 VFS : mount lock ... |
3619 3620 |
} return mnt; |
9d412a43c vfs: split off vf... |
3621 |
} |
d911b4585 vfs: Remove kern_... |
3622 |
EXPORT_SYMBOL_GPL(kern_mount); |
423e0ab08 VFS : mount lock ... |
3623 3624 3625 3626 3627 |
void kern_unmount(struct vfsmount *mnt) { /* release long term mount so mount point can be released */ if (!IS_ERR_OR_NULL(mnt)) { |
f7a99c5b7 get rid of ->mnt_... |
3628 |
real_mount(mnt)->mnt_ns = NULL; |
48a066e72 RCU'd vfsmounts |
3629 |
synchronize_rcu(); /* yecchhh... */ |
423e0ab08 VFS : mount lock ... |
3630 3631 3632 3633 |
mntput(mnt); } } EXPORT_SYMBOL(kern_unmount); |
02125a826 fix apparmor dere... |
3634 3635 3636 |
bool our_mnt(struct vfsmount *mnt) { |
143c8c91c vfs: mnt_ns moved... |
3637 |
return check_mnt(real_mount(mnt)); |
02125a826 fix apparmor dere... |
3638 |
} |
8823c079b vfs: Add setns su... |
3639 |
|
3151527ee userns: Don't al... |
3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 |
bool current_chrooted(void) { /* Does the current process have a non-standard root */ struct path ns_root; struct path fs_root; bool chrooted; /* Find the namespace root */ ns_root.mnt = ¤t->nsproxy->mnt_ns->root->mnt; ns_root.dentry = ns_root.mnt->mnt_root; path_get(&ns_root); while (d_mountpoint(ns_root.dentry) && follow_down_one(&ns_root)) ; get_fs_root(current->fs, &fs_root); chrooted = !path_equal(&fs_root, &ns_root); path_put(&fs_root); path_put(&ns_root); return chrooted; } |
132e46084 new helper: do_ne... |
3663 3664 |
static bool mnt_already_visible(struct mnt_namespace *ns, const struct super_block *sb, |
8654df4e2 mnt: Refactor fs_... |
3665 |
int *new_mnt_flags) |
87a8ebd63 userns: Restrict ... |
3666 |
{ |
8c6cf9cc8 mnt: Modify fs_fu... |
3667 |
int new_flags = *new_mnt_flags; |
87a8ebd63 userns: Restrict ... |
3668 |
struct mount *mnt; |
e51db7353 userns: Better re... |
3669 |
bool visible = false; |
87a8ebd63 userns: Restrict ... |
3670 |
|
44bb4385c fs_is_visible onl... |
3671 |
down_read(&namespace_sem); |
87a8ebd63 userns: Restrict ... |
3672 |
list_for_each_entry(mnt, &ns->list, mnt_list) { |
e51db7353 userns: Better re... |
3673 |
struct mount *child; |
77b1a97d2 mnt: fs_fully_vis... |
3674 |
int mnt_flags; |
132e46084 new helper: do_ne... |
3675 |
if (mnt->mnt.mnt_sb->s_type != sb->s_type) |
e51db7353 userns: Better re... |
3676 |
continue; |
7e96c1b0e mnt: Fix fs_fully... |
3677 3678 3679 3680 3681 |
/* This mount is not fully visible if it's root directory * is not the root directory of the filesystem. */ if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root) continue; |
a1935c173 mnt: Simplify mou... |
3682 |
/* A local view of the mount flags */ |
77b1a97d2 mnt: fs_fully_vis... |
3683 |
mnt_flags = mnt->mnt.mnt_flags; |
77b1a97d2 mnt: fs_fully_vis... |
3684 |
|
695e9df01 mnt: Account for ... |
3685 |
/* Don't miss readonly hidden in the superblock flags */ |
bc98a42c1 VFS: Convert sb->... |
3686 |
if (sb_rdonly(mnt->mnt.mnt_sb)) |
695e9df01 mnt: Account for ... |
3687 |
mnt_flags |= MNT_LOCK_READONLY; |
8c6cf9cc8 mnt: Modify fs_fu... |
3688 3689 3690 |
/* Verify the mount flags are equal to or more permissive * than the proposed new mount. */ |
77b1a97d2 mnt: fs_fully_vis... |
3691 |
if ((mnt_flags & MNT_LOCK_READONLY) && |
8c6cf9cc8 mnt: Modify fs_fu... |
3692 3693 |
!(new_flags & MNT_READONLY)) continue; |
77b1a97d2 mnt: fs_fully_vis... |
3694 3695 |
if ((mnt_flags & MNT_LOCK_ATIME) && ((mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK))) |
8c6cf9cc8 mnt: Modify fs_fu... |
3696 |
continue; |
ceeb0e5d3 vfs: Ignore unloc... |
3697 3698 3699 |
/* This mount is not fully visible if there are any * locked child mounts that cover anything except for * empty directories. |
e51db7353 userns: Better re... |
3700 3701 3702 |
*/ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { struct inode *inode = child->mnt_mountpoint->d_inode; |
ceeb0e5d3 vfs: Ignore unloc... |
3703 |
/* Only worry about locked mounts */ |
d71ed6c93 mnt: fs_fully_vis... |
3704 |
if (!(child->mnt.mnt_flags & MNT_LOCKED)) |
ceeb0e5d3 vfs: Ignore unloc... |
3705 |
continue; |
7236c85e1 mnt: Update fs_fu... |
3706 3707 |
/* Is the directory permanetly empty? */ if (!is_empty_dir_inode(inode)) |
e51db7353 userns: Better re... |
3708 |
goto next; |
87a8ebd63 userns: Restrict ... |
3709 |
} |
8c6cf9cc8 mnt: Modify fs_fu... |
3710 |
/* Preserve the locked attributes */ |
77b1a97d2 mnt: fs_fully_vis... |
3711 |
*new_mnt_flags |= mnt_flags & (MNT_LOCK_READONLY | \ |
77b1a97d2 mnt: fs_fully_vis... |
3712 |
MNT_LOCK_ATIME); |
e51db7353 userns: Better re... |
3713 3714 3715 |
visible = true; goto found; next: ; |
87a8ebd63 userns: Restrict ... |
3716 |
} |
e51db7353 userns: Better re... |
3717 |
found: |
44bb4385c fs_is_visible onl... |
3718 |
up_read(&namespace_sem); |
e51db7353 userns: Better re... |
3719 |
return visible; |
87a8ebd63 userns: Restrict ... |
3720 |
} |
132e46084 new helper: do_ne... |
3721 |
static bool mount_too_revealing(const struct super_block *sb, int *new_mnt_flags) |
8654df4e2 mnt: Refactor fs_... |
3722 |
{ |
a1935c173 mnt: Simplify mou... |
3723 |
const unsigned long required_iflags = SB_I_NOEXEC | SB_I_NODEV; |
8654df4e2 mnt: Refactor fs_... |
3724 3725 3726 3727 3728 3729 3730 |
struct mnt_namespace *ns = current->nsproxy->mnt_ns; unsigned long s_iflags; if (ns->user_ns == &init_user_ns) return false; /* Can this filesystem be too revealing? */ |
132e46084 new helper: do_ne... |
3731 |
s_iflags = sb->s_iflags; |
8654df4e2 mnt: Refactor fs_... |
3732 3733 |
if (!(s_iflags & SB_I_USERNS_VISIBLE)) return false; |
a1935c173 mnt: Simplify mou... |
3734 3735 3736 3737 3738 3739 |
if ((s_iflags & required_iflags) != required_iflags) { WARN_ONCE(1, "Expected s_iflags to contain 0x%lx ", required_iflags); return true; } |
132e46084 new helper: do_ne... |
3740 |
return !mnt_already_visible(ns, sb, new_mnt_flags); |
8654df4e2 mnt: Refactor fs_... |
3741 |
} |
380cf5ba6 fs: Treat foreign... |
3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 |
bool mnt_may_suid(struct vfsmount *mnt) { /* * Foreign mounts (accessed via fchdir or through /proc * symlinks) are always treated as if they are nosuid. This * prevents namespaces from trusting potentially unsafe * suid/sgid bits, file caps, or security labels that originate * in other namespaces. */ return !(mnt->mnt_flags & MNT_NOSUID) && check_mnt(real_mount(mnt)) && current_in_userns(mnt->mnt_sb->s_user_ns); } |
64964528b make proc_ns_oper... |
3754 |
static struct ns_common *mntns_get(struct task_struct *task) |
8823c079b vfs: Add setns su... |
3755 |
{ |
58be28256 make mntns ->get(... |
3756 |
struct ns_common *ns = NULL; |
8823c079b vfs: Add setns su... |
3757 |
struct nsproxy *nsproxy; |
728dba3a3 namespaces: Use t... |
3758 3759 |
task_lock(task); nsproxy = task->nsproxy; |
8823c079b vfs: Add setns su... |
3760 |
if (nsproxy) { |
58be28256 make mntns ->get(... |
3761 3762 |
ns = &nsproxy->mnt_ns->ns; get_mnt_ns(to_mnt_ns(ns)); |
8823c079b vfs: Add setns su... |
3763 |
} |
728dba3a3 namespaces: Use t... |
3764 |
task_unlock(task); |
8823c079b vfs: Add setns su... |
3765 3766 3767 |
return ns; } |
64964528b make proc_ns_oper... |
3768 |
static void mntns_put(struct ns_common *ns) |
8823c079b vfs: Add setns su... |
3769 |
{ |
58be28256 make mntns ->get(... |
3770 |
put_mnt_ns(to_mnt_ns(ns)); |
8823c079b vfs: Add setns su... |
3771 |
} |
64964528b make proc_ns_oper... |
3772 |
static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns) |
8823c079b vfs: Add setns su... |
3773 3774 |
{ struct fs_struct *fs = current->fs; |
4f757f3cb make sure that mn... |
3775 |
struct mnt_namespace *mnt_ns = to_mnt_ns(ns), *old_mnt_ns; |
8823c079b vfs: Add setns su... |
3776 |
struct path root; |
4f757f3cb make sure that mn... |
3777 |
int err; |
8823c079b vfs: Add setns su... |
3778 |
|
0c55cfc41 vfs: Allow unpriv... |
3779 |
if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) || |
c7b96acf1 userns: Kill nso... |
3780 3781 |
!ns_capable(current_user_ns(), CAP_SYS_CHROOT) || !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) |
ae11e0f18 userns: fix retur... |
3782 |
return -EPERM; |
8823c079b vfs: Add setns su... |
3783 |
|
74e831221 saner handling of... |
3784 3785 |
if (is_anon_ns(mnt_ns)) return -EINVAL; |
8823c079b vfs: Add setns su... |
3786 3787 3788 3789 |
if (fs->users != 1) return -EINVAL; get_mnt_ns(mnt_ns); |
4f757f3cb make sure that mn... |
3790 |
old_mnt_ns = nsproxy->mnt_ns; |
8823c079b vfs: Add setns su... |
3791 3792 3793 |
nsproxy->mnt_ns = mnt_ns; /* Find the root */ |
4f757f3cb make sure that mn... |
3794 3795 3796 3797 3798 3799 3800 3801 |
err = vfs_path_lookup(mnt_ns->root->mnt.mnt_root, &mnt_ns->root->mnt, "/", LOOKUP_DOWN, &root); if (err) { /* revert to old namespace */ nsproxy->mnt_ns = old_mnt_ns; put_mnt_ns(mnt_ns); return err; } |
8823c079b vfs: Add setns su... |
3802 |
|
4068367c9 fs: don't forget ... |
3803 |
put_mnt_ns(old_mnt_ns); |
8823c079b vfs: Add setns su... |
3804 3805 3806 3807 3808 3809 3810 |
/* Update the pwd and root */ set_fs_pwd(fs, &root); set_fs_root(fs, &root); path_put(&root); return 0; } |
bcac25a58 kernel: add a hel... |
3811 3812 3813 3814 |
static struct user_namespace *mntns_owner(struct ns_common *ns) { return to_mnt_ns(ns)->user_ns; } |
8823c079b vfs: Add setns su... |
3815 3816 3817 3818 3819 3820 |
const struct proc_ns_operations mntns_operations = { .name = "mnt", .type = CLONE_NEWNS, .get = mntns_get, .put = mntns_put, .install = mntns_install, |
bcac25a58 kernel: add a hel... |
3821 |
.owner = mntns_owner, |
8823c079b vfs: Add setns su... |
3822 |
}; |