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fs/namespace.c
84.6 KB
1da177e4c Linux-2.6.12-rc2 |
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/* * linux/fs/namespace.c * * (C) Copyright Al Viro 2000, 2001 * Released under GPL v2. * * 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 */ #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/bootmem.h> |
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#include <linux/task_work.h> |
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#include <linux/sched/task.h> |
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#include "pnode.h" |
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#include "internal.h" |
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|
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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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|
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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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|
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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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|
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/* /sys/fs */ |
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struct kobject *fs_kobj; EXPORT_SYMBOL_GPL(fs_kobj); |
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|
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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 void drop_mountpoint(struct fs_pin *p) { struct mount *m = container_of(p, struct mount, mnt_umount); dput(m->mnt_ex_mountpoint); pin_remove(p); mntput(&m->mnt); } |
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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_fs_pin(&mnt->mnt_umount, drop_mountpoint); |
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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. */ int __mnt_is_readonly(struct vfsmount *mnt) { |
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if (mnt->mnt_flags & MNT_READONLY) return 1; |
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if (sb_rdonly(mnt->mnt_sb)) |
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return 1; return 0; |
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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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{ |
83f936c75 mark struct file ... |
383 |
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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* 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 |
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*/ int mnt_want_write_file(struct file *file) { int ret; |
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sb_start_write(file_inode(file)->i_sb); |
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ret = __mnt_want_write_file(file); if (ret) |
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402 |
sb_end_write(file_inode(file)->i_sb); |
7c6893e3c ovl: don't allow ... |
403 404 |
return ret; } |
96029c4e0 fs: introduce mnt... |
405 406 407 |
EXPORT_SYMBOL_GPL(mnt_want_write_file); /** |
eb04c2828 fs: Add freezing ... |
408 |
* __mnt_drop_write - give up write access to a mount |
8366025eb [PATCH] r/o bind ... |
409 410 411 412 |
* @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 ... |
413 |
* __mnt_want_write() call above. |
8366025eb [PATCH] r/o bind ... |
414 |
*/ |
eb04c2828 fs: Add freezing ... |
415 |
void __mnt_drop_write(struct vfsmount *mnt) |
8366025eb [PATCH] r/o bind ... |
416 |
{ |
d3ef3d735 fs: mnt_want_writ... |
417 |
preempt_disable(); |
83adc7532 vfs: spread struc... |
418 |
mnt_dec_writers(real_mount(mnt)); |
d3ef3d735 fs: mnt_want_writ... |
419 |
preempt_enable(); |
8366025eb [PATCH] r/o bind ... |
420 |
} |
eb04c2828 fs: Add freezing ... |
421 422 423 424 425 426 427 428 429 430 431 432 433 434 |
/** * 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 ... |
435 |
EXPORT_SYMBOL_GPL(mnt_drop_write); |
eb04c2828 fs: Add freezing ... |
436 437 438 439 |
void __mnt_drop_write_file(struct file *file) { __mnt_drop_write(file->f_path.mnt); } |
7c6893e3c ovl: don't allow ... |
440 441 |
void mnt_drop_write_file(struct file *file) { |
a6795a585 vfs: fix freeze p... |
442 |
__mnt_drop_write_file(file); |
7c6893e3c ovl: don't allow ... |
443 444 |
sb_end_write(file_inode(file)->i_sb); } |
2a79f17e4 vfs: mnt_drop_wri... |
445 |
EXPORT_SYMBOL(mnt_drop_write_file); |
83adc7532 vfs: spread struc... |
446 |
static int mnt_make_readonly(struct mount *mnt) |
8366025eb [PATCH] r/o bind ... |
447 |
{ |
3d733633a [PATCH] r/o bind ... |
448 |
int ret = 0; |
719ea2fbb new helpers: lock... |
449 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
450 |
mnt->mnt.mnt_flags |= MNT_WRITE_HOLD; |
3d733633a [PATCH] r/o bind ... |
451 |
/* |
d3ef3d735 fs: mnt_want_writ... |
452 453 |
* After storing MNT_WRITE_HOLD, we'll read the counters. This store * should be visible before we do. |
3d733633a [PATCH] r/o bind ... |
454 |
*/ |
d3ef3d735 fs: mnt_want_writ... |
455 |
smp_mb(); |
3d733633a [PATCH] r/o bind ... |
456 |
/* |
d3ef3d735 fs: mnt_want_writ... |
457 458 459 460 461 462 463 464 465 466 467 468 469 470 |
* 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 ... |
471 |
*/ |
c6653a838 fs: rename vfsmou... |
472 |
if (mnt_get_writers(mnt) > 0) |
d3ef3d735 fs: mnt_want_writ... |
473 474 |
ret = -EBUSY; else |
83adc7532 vfs: spread struc... |
475 |
mnt->mnt.mnt_flags |= MNT_READONLY; |
d3ef3d735 fs: mnt_want_writ... |
476 477 478 479 480 |
/* * MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers * that become unheld will see MNT_READONLY. */ smp_wmb(); |
83adc7532 vfs: spread struc... |
481 |
mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD; |
719ea2fbb new helpers: lock... |
482 |
unlock_mount_hash(); |
3d733633a [PATCH] r/o bind ... |
483 |
return ret; |
8366025eb [PATCH] r/o bind ... |
484 |
} |
8366025eb [PATCH] r/o bind ... |
485 |
|
83adc7532 vfs: spread struc... |
486 |
static void __mnt_unmake_readonly(struct mount *mnt) |
2e4b7fcd9 [PATCH] r/o bind ... |
487 |
{ |
719ea2fbb new helpers: lock... |
488 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
489 |
mnt->mnt.mnt_flags &= ~MNT_READONLY; |
719ea2fbb new helpers: lock... |
490 |
unlock_mount_hash(); |
2e4b7fcd9 [PATCH] r/o bind ... |
491 |
} |
4ed5e82fe vfs: protect remo... |
492 493 494 495 |
int sb_prepare_remount_readonly(struct super_block *sb) { struct mount *mnt; int err = 0; |
8e8b87964 vfs: prevent remo... |
496 497 498 |
/* Racy optimization. Recheck the counter under MNT_WRITE_HOLD */ if (atomic_long_read(&sb->s_remove_count)) return -EBUSY; |
719ea2fbb new helpers: lock... |
499 |
lock_mount_hash(); |
4ed5e82fe vfs: protect remo... |
500 501 502 503 504 505 506 507 508 509 |
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... |
510 511 |
if (!err && atomic_long_read(&sb->s_remove_count)) err = -EBUSY; |
4ed5e82fe vfs: protect remo... |
512 513 514 515 516 517 518 519 |
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... |
520 |
unlock_mount_hash(); |
4ed5e82fe vfs: protect remo... |
521 522 523 |
return err; } |
b105e270b vfs: spread struc... |
524 |
static void free_vfsmnt(struct mount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
525 |
{ |
fcc139ae2 fs/namespace: con... |
526 |
kfree_const(mnt->mnt_devname); |
d3ef3d735 fs: mnt_want_writ... |
527 |
#ifdef CONFIG_SMP |
68e8a9fea vfs: all counters... |
528 |
free_percpu(mnt->mnt_pcp); |
d3ef3d735 fs: mnt_want_writ... |
529 |
#endif |
b105e270b vfs: spread struc... |
530 |
kmem_cache_free(mnt_cache, mnt); |
1da177e4c Linux-2.6.12-rc2 |
531 |
} |
8ffcb32e0 VFS: Make delayed... |
532 533 534 535 |
static void delayed_free_vfsmnt(struct rcu_head *head) { free_vfsmnt(container_of(head, struct mount, mnt_rcu)); } |
48a066e72 RCU'd vfsmounts |
536 |
/* call under rcu_read_lock */ |
294d71ff2 new helper: __leg... |
537 |
int __legitimize_mnt(struct vfsmount *bastard, unsigned seq) |
48a066e72 RCU'd vfsmounts |
538 539 540 |
{ struct mount *mnt; if (read_seqretry(&mount_lock, seq)) |
294d71ff2 new helper: __leg... |
541 |
return 1; |
48a066e72 RCU'd vfsmounts |
542 |
if (bastard == NULL) |
294d71ff2 new helper: __leg... |
543 |
return 0; |
48a066e72 RCU'd vfsmounts |
544 545 |
mnt = real_mount(bastard); mnt_add_count(mnt, 1); |
119e1ef80 fix __legitimize_... |
546 |
smp_mb(); // see mntput_no_expire() |
48a066e72 RCU'd vfsmounts |
547 |
if (likely(!read_seqretry(&mount_lock, seq))) |
294d71ff2 new helper: __leg... |
548 |
return 0; |
48a066e72 RCU'd vfsmounts |
549 550 |
if (bastard->mnt_flags & MNT_SYNC_UMOUNT) { mnt_add_count(mnt, -1); |
294d71ff2 new helper: __leg... |
551 552 |
return 1; } |
119e1ef80 fix __legitimize_... |
553 554 555 556 557 558 559 560 |
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... |
561 562 563 564 565 566 567 568 569 570 571 572 573 |
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 |
574 |
} |
48a066e72 RCU'd vfsmounts |
575 576 |
return false; } |
1da177e4c Linux-2.6.12-rc2 |
577 |
/* |
474279dc0 split __lookup_mn... |
578 |
* find the first mount at @dentry on vfsmount @mnt. |
48a066e72 RCU'd vfsmounts |
579 |
* call under rcu_read_lock() |
1da177e4c Linux-2.6.12-rc2 |
580 |
*/ |
474279dc0 split __lookup_mn... |
581 |
struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4c Linux-2.6.12-rc2 |
582 |
{ |
38129a13e switch mnt_hash t... |
583 |
struct hlist_head *head = m_hash(mnt, dentry); |
474279dc0 split __lookup_mn... |
584 |
struct mount *p; |
38129a13e switch mnt_hash t... |
585 |
hlist_for_each_entry_rcu(p, head, mnt_hash) |
474279dc0 split __lookup_mn... |
586 587 588 589 590 591 |
if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) return p; return NULL; } /* |
f015f1267 VFS: Comment moun... |
592 593 594 595 596 597 598 599 600 601 602 603 604 605 |
* 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... |
606 |
*/ |
ca71cf71e namespace.c: cons... |
607 |
struct vfsmount *lookup_mnt(const struct path *path) |
a05964f39 [PATCH] shared mo... |
608 |
{ |
c71053659 vfs: spread struc... |
609 |
struct mount *child_mnt; |
48a066e72 RCU'd vfsmounts |
610 611 |
struct vfsmount *m; unsigned seq; |
99b7db7b8 fs: brlock vfsmou... |
612 |
|
48a066e72 RCU'd vfsmounts |
613 614 615 616 617 618 619 620 |
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... |
621 |
} |
7af1364ff vfs: Don't allow ... |
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 |
/* * __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... |
656 |
static struct mountpoint *lookup_mountpoint(struct dentry *dentry) |
84d17192d get rid of full-h... |
657 |
{ |
0818bf27c resizable namespa... |
658 |
struct hlist_head *chain = mp_hash(dentry); |
84d17192d get rid of full-h... |
659 |
struct mountpoint *mp; |
0818bf27c resizable namespa... |
660 |
hlist_for_each_entry(mp, chain, m_hash) { |
84d17192d get rid of full-h... |
661 |
if (mp->m_dentry == dentry) { |
84d17192d get rid of full-h... |
662 663 664 665 |
mp->m_count++; return mp; } } |
e2dfa9354 vfs: factor out l... |
666 667 |
return NULL; } |
3895dbf89 mnt: Protect the ... |
668 |
static struct mountpoint *get_mountpoint(struct dentry *dentry) |
e2dfa9354 vfs: factor out l... |
669 |
{ |
3895dbf89 mnt: Protect the ... |
670 |
struct mountpoint *mp, *new = NULL; |
e2dfa9354 vfs: factor out l... |
671 |
int ret; |
84d17192d get rid of full-h... |
672 |
|
3895dbf89 mnt: Protect the ... |
673 |
if (d_mountpoint(dentry)) { |
83eec9ad8 mnt: fix __detach... |
674 675 676 |
/* might be worth a WARN_ON() */ if (d_unlinked(dentry)) return ERR_PTR(-ENOENT); |
3895dbf89 mnt: Protect the ... |
677 678 679 680 681 682 683 684 685 686 687 |
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... |
688 |
return ERR_PTR(-ENOMEM); |
3895dbf89 mnt: Protect the ... |
689 690 |
/* Exactly one processes may set d_mounted */ |
eed810076 vfs: check unlink... |
691 |
ret = d_set_mounted(dentry); |
eed810076 vfs: check unlink... |
692 |
|
3895dbf89 mnt: Protect the ... |
693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 |
/* 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); new->m_dentry = dentry; 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... |
714 715 716 717 718 719 720 |
return mp; } static void put_mountpoint(struct mountpoint *mp) { 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); |
0818bf27c resizable namespa... |
725 |
hlist_del(&mp->m_hash); |
84d17192d get rid of full-h... |
726 727 728 |
kfree(mp); } } |
143c8c91c vfs: mnt_ns moved... |
729 |
static inline int check_mnt(struct mount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
730 |
{ |
6b3286ed1 [PATCH] rename st... |
731 |
return mnt->mnt_ns == current->nsproxy->mnt_ns; |
1da177e4c Linux-2.6.12-rc2 |
732 |
} |
99b7db7b8 fs: brlock vfsmou... |
733 734 735 |
/* * vfsmount lock must be held for write */ |
6b3286ed1 [PATCH] rename st... |
736 |
static void touch_mnt_namespace(struct mnt_namespace *ns) |
5addc5dd8 [PATCH] make /pro... |
737 738 739 740 741 742 |
{ if (ns) { ns->event = ++event; wake_up_interruptible(&ns->poll); } } |
99b7db7b8 fs: brlock vfsmou... |
743 744 745 |
/* * vfsmount lock must be held for write */ |
6b3286ed1 [PATCH] rename st... |
746 |
static void __touch_mnt_namespace(struct mnt_namespace *ns) |
5addc5dd8 [PATCH] make /pro... |
747 748 749 750 751 752 |
{ if (ns && ns->event != event) { ns->event = event; wake_up_interruptible(&ns->poll); } } |
99b7db7b8 fs: brlock vfsmou... |
753 754 755 |
/* * vfsmount lock must be held for write */ |
7bdb11de8 mnt: Factor out u... |
756 |
static void unhash_mnt(struct mount *mnt) |
419148da6 vfs: spread struc... |
757 |
{ |
0714a5338 vfs: now it can b... |
758 |
mnt->mnt_parent = mnt; |
a73324da7 vfs: move mnt_mou... |
759 |
mnt->mnt_mountpoint = mnt->mnt.mnt_root; |
6b41d536f vfs: take mnt_chi... |
760 |
list_del_init(&mnt->mnt_child); |
38129a13e switch mnt_hash t... |
761 |
hlist_del_init_rcu(&mnt->mnt_hash); |
0a5eb7c81 vfs: Keep a list ... |
762 |
hlist_del_init(&mnt->mnt_mp_list); |
84d17192d get rid of full-h... |
763 764 |
put_mountpoint(mnt->mnt_mp); mnt->mnt_mp = NULL; |
1da177e4c Linux-2.6.12-rc2 |
765 |
} |
99b7db7b8 fs: brlock vfsmou... |
766 767 768 |
/* * vfsmount lock must be held for write */ |
7bdb11de8 mnt: Factor out u... |
769 770 771 772 773 774 775 776 777 778 |
static void detach_mnt(struct mount *mnt, struct path *old_path) { old_path->dentry = mnt->mnt_mountpoint; old_path->mnt = &mnt->mnt_parent->mnt; unhash_mnt(mnt); } /* * vfsmount lock must be held for write */ |
6a46c5735 mnt: Factor umoun... |
779 780 781 782 783 784 785 786 787 788 |
static void umount_mnt(struct mount *mnt) { /* old mountpoint will be dropped when we can do that */ mnt->mnt_ex_mountpoint = mnt->mnt_mountpoint; unhash_mnt(mnt); } /* * vfsmount lock must be held for write */ |
84d17192d get rid of full-h... |
789 790 |
void mnt_set_mountpoint(struct mount *mnt, struct mountpoint *mp, |
44d964d60 vfs: spread struc... |
791 |
struct mount *child_mnt) |
b90fa9ae8 [PATCH] shared mo... |
792 |
{ |
84d17192d get rid of full-h... |
793 |
mp->m_count++; |
3a2393d71 vfs: opencode mnt... |
794 |
mnt_add_count(mnt, 1); /* essentially, that's mntget */ |
84d17192d get rid of full-h... |
795 |
child_mnt->mnt_mountpoint = dget(mp->m_dentry); |
3a2393d71 vfs: opencode mnt... |
796 |
child_mnt->mnt_parent = mnt; |
84d17192d get rid of full-h... |
797 |
child_mnt->mnt_mp = mp; |
0a5eb7c81 vfs: Keep a list ... |
798 |
hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list); |
b90fa9ae8 [PATCH] shared mo... |
799 |
} |
1064f874a mnt: Tuck mounts ... |
800 801 802 803 804 805 |
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... |
806 807 808 |
/* * vfsmount lock must be held for write */ |
84d17192d get rid of full-h... |
809 810 811 |
static void attach_mnt(struct mount *mnt, struct mount *parent, struct mountpoint *mp) |
1da177e4c Linux-2.6.12-rc2 |
812 |
{ |
84d17192d get rid of full-h... |
813 |
mnt_set_mountpoint(parent, mp, mnt); |
1064f874a mnt: Tuck mounts ... |
814 |
__attach_mnt(mnt, parent); |
b90fa9ae8 [PATCH] shared mo... |
815 |
} |
1064f874a mnt: Tuck mounts ... |
816 |
void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *mnt) |
12a5b5294 fix copy_tree() r... |
817 |
{ |
1064f874a mnt: Tuck mounts ... |
818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 |
struct mountpoint *old_mp = mnt->mnt_mp; struct dentry *old_mountpoint = mnt->mnt_mountpoint; 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); /* * Safely avoid even the suggestion this code might sleep or * lock the mount hash by taking advantage of the knowledge that * mnt_change_mountpoint will not release the final reference * to a mountpoint. * * During mounting, the mount passed in as the parent mount will * continue to use the old mountpoint and during unmounting, the * old mountpoint will continue to exist until namespace_unlock, * which happens well after mnt_change_mountpoint. */ spin_lock(&old_mountpoint->d_lock); old_mountpoint->d_lockref.count--; spin_unlock(&old_mountpoint->d_lock); mnt_add_count(old_parent, -1); |
12a5b5294 fix copy_tree() r... |
846 |
} |
b90fa9ae8 [PATCH] shared mo... |
847 |
/* |
99b7db7b8 fs: brlock vfsmou... |
848 |
* vfsmount lock must be held for write |
b90fa9ae8 [PATCH] shared mo... |
849 |
*/ |
1064f874a mnt: Tuck mounts ... |
850 |
static void commit_tree(struct mount *mnt) |
b90fa9ae8 [PATCH] shared mo... |
851 |
{ |
0714a5338 vfs: now it can b... |
852 |
struct mount *parent = mnt->mnt_parent; |
83adc7532 vfs: spread struc... |
853 |
struct mount *m; |
b90fa9ae8 [PATCH] shared mo... |
854 |
LIST_HEAD(head); |
143c8c91c vfs: mnt_ns moved... |
855 |
struct mnt_namespace *n = parent->mnt_ns; |
b90fa9ae8 [PATCH] shared mo... |
856 |
|
0714a5338 vfs: now it can b... |
857 |
BUG_ON(parent == mnt); |
b90fa9ae8 [PATCH] shared mo... |
858 |
|
1a4eeaf2a vfs: move mnt_lis... |
859 |
list_add_tail(&head, &mnt->mnt_list); |
f7a99c5b7 get rid of ->mnt_... |
860 |
list_for_each_entry(m, &head, mnt_list) |
143c8c91c vfs: mnt_ns moved... |
861 |
m->mnt_ns = n; |
f03c65993 sanitize vfsmount... |
862 |
|
b90fa9ae8 [PATCH] shared mo... |
863 |
list_splice(&head, n->list.prev); |
d29216842 mnt: Add a per mo... |
864 865 |
n->mounts += n->pending_mounts; n->pending_mounts = 0; |
1064f874a mnt: Tuck mounts ... |
866 |
__attach_mnt(mnt, parent); |
6b3286ed1 [PATCH] rename st... |
867 |
touch_mnt_namespace(n); |
1da177e4c Linux-2.6.12-rc2 |
868 |
} |
909b0a88e vfs: spread struc... |
869 |
static struct mount *next_mnt(struct mount *p, struct mount *root) |
1da177e4c Linux-2.6.12-rc2 |
870 |
{ |
6b41d536f vfs: take mnt_chi... |
871 872 |
struct list_head *next = p->mnt_mounts.next; if (next == &p->mnt_mounts) { |
1da177e4c Linux-2.6.12-rc2 |
873 |
while (1) { |
909b0a88e vfs: spread struc... |
874 |
if (p == root) |
1da177e4c Linux-2.6.12-rc2 |
875 |
return NULL; |
6b41d536f vfs: take mnt_chi... |
876 877 |
next = p->mnt_child.next; if (next != &p->mnt_parent->mnt_mounts) |
1da177e4c Linux-2.6.12-rc2 |
878 |
break; |
0714a5338 vfs: now it can b... |
879 |
p = p->mnt_parent; |
1da177e4c Linux-2.6.12-rc2 |
880 881 |
} } |
6b41d536f vfs: take mnt_chi... |
882 |
return list_entry(next, struct mount, mnt_child); |
1da177e4c Linux-2.6.12-rc2 |
883 |
} |
315fc83e5 vfs: spread struc... |
884 |
static struct mount *skip_mnt_tree(struct mount *p) |
9676f0c63 [PATCH] unbindabl... |
885 |
{ |
6b41d536f vfs: take mnt_chi... |
886 887 888 889 |
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... |
890 891 892 |
} return p; } |
9d412a43c vfs: split off vf... |
893 894 895 |
struct vfsmount * vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data) { |
b105e270b vfs: spread struc... |
896 |
struct mount *mnt; |
9d412a43c vfs: split off vf... |
897 898 899 900 901 902 903 904 |
struct dentry *root; if (!type) return ERR_PTR(-ENODEV); mnt = alloc_vfsmnt(name); if (!mnt) return ERR_PTR(-ENOMEM); |
e462ec50c VFS: Differentiat... |
905 |
if (flags & SB_KERNMOUNT) |
b105e270b vfs: spread struc... |
906 |
mnt->mnt.mnt_flags = MNT_INTERNAL; |
9d412a43c vfs: split off vf... |
907 908 909 |
root = mount_fs(type, flags, name, data); if (IS_ERR(root)) { |
8ffcb32e0 VFS: Make delayed... |
910 |
mnt_free_id(mnt); |
9d412a43c vfs: split off vf... |
911 912 913 |
free_vfsmnt(mnt); return ERR_CAST(root); } |
b105e270b vfs: spread struc... |
914 915 |
mnt->mnt.mnt_root = root; mnt->mnt.mnt_sb = root->d_sb; |
a73324da7 vfs: move mnt_mou... |
916 |
mnt->mnt_mountpoint = mnt->mnt.mnt_root; |
0714a5338 vfs: now it can b... |
917 |
mnt->mnt_parent = mnt; |
719ea2fbb new helpers: lock... |
918 |
lock_mount_hash(); |
39f7c4db1 vfs: keep list of... |
919 |
list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts); |
719ea2fbb new helpers: lock... |
920 |
unlock_mount_hash(); |
b105e270b vfs: spread struc... |
921 |
return &mnt->mnt; |
9d412a43c vfs: split off vf... |
922 923 |
} EXPORT_SYMBOL_GPL(vfs_kern_mount); |
93faccbbf fs: Better permis... |
924 925 926 927 928 929 930 931 932 933 |
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... |
934 |
return vfs_kern_mount(type, SB_SUBMOUNT, name, data); |
93faccbbf fs: Better permis... |
935 936 |
} EXPORT_SYMBOL_GPL(vfs_submount); |
87129cc0e vfs: spread struc... |
937 |
static struct mount *clone_mnt(struct mount *old, struct dentry *root, |
36341f645 [PATCH] mount exp... |
938 |
int flag) |
1da177e4c Linux-2.6.12-rc2 |
939 |
{ |
87129cc0e vfs: spread struc... |
940 |
struct super_block *sb = old->mnt.mnt_sb; |
be34d1a3b VFS: Make clone_m... |
941 942 |
struct mount *mnt; int err; |
1da177e4c Linux-2.6.12-rc2 |
943 |
|
be34d1a3b VFS: Make clone_m... |
944 945 946 |
mnt = alloc_vfsmnt(old->mnt_devname); if (!mnt) return ERR_PTR(-ENOMEM); |
719f5d7f0 [patch 4/7] vfs: ... |
947 |
|
7a472ef4b vfs: Only support... |
948 |
if (flag & (CL_SLAVE | CL_PRIVATE | CL_SHARED_TO_SLAVE)) |
be34d1a3b VFS: Make clone_m... |
949 950 951 |
mnt->mnt_group_id = 0; /* not a peer of original */ else mnt->mnt_group_id = old->mnt_group_id; |
b90fa9ae8 [PATCH] shared mo... |
952 |
|
be34d1a3b VFS: Make clone_m... |
953 954 955 956 |
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 |
957 |
} |
be34d1a3b VFS: Make clone_m... |
958 |
|
16a34adb9 Don't leak MNT_IN... |
959 960 |
mnt->mnt.mnt_flags = old->mnt.mnt_flags; mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL); |
132c94e31 vfs: Carefully pr... |
961 |
/* Don't allow unprivileged users to change mount flags */ |
9566d6742 mnt: Correct perm... |
962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 |
if (flag & CL_UNPRIVILEGED) { mnt->mnt.mnt_flags |= MNT_LOCK_ATIME; if (mnt->mnt.mnt_flags & MNT_READONLY) mnt->mnt.mnt_flags |= MNT_LOCK_READONLY; if (mnt->mnt.mnt_flags & MNT_NODEV) mnt->mnt.mnt_flags |= MNT_LOCK_NODEV; if (mnt->mnt.mnt_flags & MNT_NOSUID) mnt->mnt.mnt_flags |= MNT_LOCK_NOSUID; if (mnt->mnt.mnt_flags & MNT_NOEXEC) mnt->mnt.mnt_flags |= MNT_LOCK_NOEXEC; } |
132c94e31 vfs: Carefully pr... |
977 |
|
5ff9d8a65 vfs: Lock in plac... |
978 |
/* Don't allow unprivileged users to reveal what is under a mount */ |
381cacb12 mnt: Carefully se... |
979 980 |
if ((flag & CL_UNPRIVILEGED) && (!(flag & CL_EXPIRE) || list_empty(&old->mnt_expire))) |
5ff9d8a65 vfs: Lock in plac... |
981 |
mnt->mnt.mnt_flags |= MNT_LOCKED; |
be34d1a3b VFS: Make clone_m... |
982 983 984 985 986 |
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... |
987 |
lock_mount_hash(); |
be34d1a3b VFS: Make clone_m... |
988 |
list_add_tail(&mnt->mnt_instance, &sb->s_mounts); |
719ea2fbb new helpers: lock... |
989 |
unlock_mount_hash(); |
be34d1a3b VFS: Make clone_m... |
990 |
|
7a472ef4b vfs: Only support... |
991 992 |
if ((flag & CL_SLAVE) || ((flag & CL_SHARED_TO_SLAVE) && IS_MNT_SHARED(old))) { |
be34d1a3b VFS: Make clone_m... |
993 994 995 996 997 998 999 1000 1001 |
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... |
1002 1003 |
} else { CLEAR_MNT_SHARED(mnt); |
be34d1a3b VFS: Make clone_m... |
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 |
} 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... |
1014 |
return mnt; |
719f5d7f0 [patch 4/7] vfs: ... |
1015 1016 |
out_free: |
8ffcb32e0 VFS: Make delayed... |
1017 |
mnt_free_id(mnt); |
719f5d7f0 [patch 4/7] vfs: ... |
1018 |
free_vfsmnt(mnt); |
be34d1a3b VFS: Make clone_m... |
1019 |
return ERR_PTR(err); |
1da177e4c Linux-2.6.12-rc2 |
1020 |
} |
9ea459e11 delayed mntput |
1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 |
static void cleanup_mnt(struct mount *mnt) { /* * This 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. */ /* * 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); 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'... |
1052 |
struct mount *m, *t; |
9ea459e11 delayed mntput |
1053 |
|
297857357 namespace.c: Don'... |
1054 1055 |
llist_for_each_entry_safe(m, t, node, mnt_llist) cleanup_mnt(m); |
9ea459e11 delayed mntput |
1056 1057 |
} static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput); |
900148dca vfs: spread struc... |
1058 |
static void mntput_no_expire(struct mount *mnt) |
b3e19d924 fs: scale mntget/... |
1059 |
{ |
48a066e72 RCU'd vfsmounts |
1060 |
rcu_read_lock(); |
9ea0a46ca fix mntput/mntput... |
1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 |
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 |
1072 |
rcu_read_unlock(); |
f03c65993 sanitize vfsmount... |
1073 |
return; |
b3e19d924 fs: scale mntget/... |
1074 |
} |
719ea2fbb new helpers: lock... |
1075 |
lock_mount_hash(); |
119e1ef80 fix __legitimize_... |
1076 1077 1078 1079 1080 |
/* * 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... |
1081 |
mnt_add_count(mnt, -1); |
b3e19d924 fs: scale mntget/... |
1082 |
if (mnt_get_count(mnt)) { |
48a066e72 RCU'd vfsmounts |
1083 |
rcu_read_unlock(); |
719ea2fbb new helpers: lock... |
1084 |
unlock_mount_hash(); |
99b7db7b8 fs: brlock vfsmou... |
1085 1086 |
return; } |
48a066e72 RCU'd vfsmounts |
1087 1088 1089 1090 1091 1092 1093 |
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: ... |
1094 |
|
39f7c4db1 vfs: keep list of... |
1095 |
list_del(&mnt->mnt_instance); |
ce07d891a mnt: Honor MNT_LO... |
1096 1097 1098 1099 1100 1101 1102 |
if (unlikely(!list_empty(&mnt->mnt_mounts))) { struct mount *p, *tmp; list_for_each_entry_safe(p, tmp, &mnt->mnt_mounts, mnt_child) { umount_mnt(p); } } |
719ea2fbb new helpers: lock... |
1103 |
unlock_mount_hash(); |
649a795af fold mntfree() in... |
1104 |
|
9ea459e11 delayed mntput |
1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 |
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/... |
1117 |
} |
b3e19d924 fs: scale mntget/... |
1118 1119 1120 1121 |
void mntput(struct vfsmount *mnt) { if (mnt) { |
863d684f9 vfs: move the res... |
1122 |
struct mount *m = real_mount(mnt); |
b3e19d924 fs: scale mntget/... |
1123 |
/* avoid cacheline pingpong, hope gcc doesn't get "smart" */ |
863d684f9 vfs: move the res... |
1124 1125 1126 |
if (unlikely(m->mnt_expiry_mark)) m->mnt_expiry_mark = 0; mntput_no_expire(m); |
b3e19d924 fs: scale mntget/... |
1127 1128 1129 1130 1131 1132 1133 |
} } EXPORT_SYMBOL(mntput); struct vfsmount *mntget(struct vfsmount *mnt) { if (mnt) |
83adc7532 vfs: spread struc... |
1134 |
mnt_add_count(real_mount(mnt), 1); |
b3e19d924 fs: scale mntget/... |
1135 1136 1137 |
return mnt; } EXPORT_SYMBOL(mntget); |
c6609c0a1 vfs: add path_is_... |
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 |
/* 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... |
1166 |
struct vfsmount *mnt_clone_internal(const struct path *path) |
7b7b1ace2 [PATCH] saner han... |
1167 |
{ |
3064c3563 death to mnt_pinned |
1168 1169 1170 1171 1172 1173 |
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... |
1174 |
} |
1da177e4c Linux-2.6.12-rc2 |
1175 |
|
a1a2c409b [patch 5/7] vfs: ... |
1176 |
#ifdef CONFIG_PROC_FS |
0226f4923 vfs: take /proc/*... |
1177 |
/* iterator; we want it to have access to namespace_sem, thus here... */ |
1da177e4c Linux-2.6.12-rc2 |
1178 1179 |
static void *m_start(struct seq_file *m, loff_t *pos) { |
ede1bf0dc fs: use seq_open_... |
1180 |
struct proc_mounts *p = m->private; |
1da177e4c Linux-2.6.12-rc2 |
1181 |
|
390c68436 [PATCH] making na... |
1182 |
down_read(&namespace_sem); |
c7999c362 reduce m_start() ... |
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 |
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 |
1197 1198 1199 1200 |
} static void *m_next(struct seq_file *m, void *v, loff_t *pos) { |
ede1bf0dc fs: use seq_open_... |
1201 |
struct proc_mounts *p = m->private; |
b0765fb85 Make /proc/self/m... |
1202 |
|
c7999c362 reduce m_start() ... |
1203 1204 1205 |
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 |
1206 1207 1208 1209 |
} static void m_stop(struct seq_file *m, void *v) { |
390c68436 [PATCH] making na... |
1210 |
up_read(&namespace_sem); |
1da177e4c Linux-2.6.12-rc2 |
1211 |
} |
0226f4923 vfs: take /proc/*... |
1212 |
static int m_show(struct seq_file *m, void *v) |
2d4d4864a [patch 6/7] vfs: ... |
1213 |
{ |
ede1bf0dc fs: use seq_open_... |
1214 |
struct proc_mounts *p = m->private; |
1a4eeaf2a vfs: move mnt_lis... |
1215 |
struct mount *r = list_entry(v, struct mount, mnt_list); |
0226f4923 vfs: take /proc/*... |
1216 |
return p->show(m, &r->mnt); |
1da177e4c Linux-2.6.12-rc2 |
1217 |
} |
a1a2c409b [patch 5/7] vfs: ... |
1218 |
const struct seq_operations mounts_op = { |
1da177e4c Linux-2.6.12-rc2 |
1219 1220 1221 |
.start = m_start, .next = m_next, .stop = m_stop, |
0226f4923 vfs: take /proc/*... |
1222 |
.show = m_show, |
b4629fe2f VFS: New /proc fi... |
1223 |
}; |
a1a2c409b [patch 5/7] vfs: ... |
1224 |
#endif /* CONFIG_PROC_FS */ |
b4629fe2f VFS: New /proc fi... |
1225 |
|
1da177e4c Linux-2.6.12-rc2 |
1226 1227 1228 1229 1230 1231 1232 1233 |
/** * 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... |
1234 |
int may_umount_tree(struct vfsmount *m) |
1da177e4c Linux-2.6.12-rc2 |
1235 |
{ |
909b0a88e vfs: spread struc... |
1236 |
struct mount *mnt = real_mount(m); |
36341f645 [PATCH] mount exp... |
1237 1238 |
int actual_refs = 0; int minimum_refs = 0; |
315fc83e5 vfs: spread struc... |
1239 |
struct mount *p; |
909b0a88e vfs: spread struc... |
1240 |
BUG_ON(!m); |
1da177e4c Linux-2.6.12-rc2 |
1241 |
|
b3e19d924 fs: scale mntget/... |
1242 |
/* write lock needed for mnt_get_count */ |
719ea2fbb new helpers: lock... |
1243 |
lock_mount_hash(); |
909b0a88e vfs: spread struc... |
1244 |
for (p = mnt; p; p = next_mnt(p, mnt)) { |
83adc7532 vfs: spread struc... |
1245 |
actual_refs += mnt_get_count(p); |
1da177e4c Linux-2.6.12-rc2 |
1246 |
minimum_refs += 2; |
1da177e4c Linux-2.6.12-rc2 |
1247 |
} |
719ea2fbb new helpers: lock... |
1248 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1249 1250 |
if (actual_refs > minimum_refs) |
e3474a8eb [PATCH] autofs4: ... |
1251 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1252 |
|
e3474a8eb [PATCH] autofs4: ... |
1253 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 |
} 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: ... |
1273 |
int ret = 1; |
8ad08d8a0 may_umount() need... |
1274 |
down_read(&namespace_sem); |
719ea2fbb new helpers: lock... |
1275 |
lock_mount_hash(); |
1ab597386 vfs: spread struc... |
1276 |
if (propagate_mount_busy(real_mount(mnt), 2)) |
e3474a8eb [PATCH] autofs4: ... |
1277 |
ret = 0; |
719ea2fbb new helpers: lock... |
1278 |
unlock_mount_hash(); |
8ad08d8a0 may_umount() need... |
1279 |
up_read(&namespace_sem); |
a05964f39 [PATCH] shared mo... |
1280 |
return ret; |
1da177e4c Linux-2.6.12-rc2 |
1281 1282 1283 |
} EXPORT_SYMBOL(may_umount); |
38129a13e switch mnt_hash t... |
1284 |
static HLIST_HEAD(unmounted); /* protected by namespace_sem */ |
e3197d83d saner umount_tree... |
1285 |
|
97216be09 fold release_moun... |
1286 |
static void namespace_unlock(void) |
70fbcdf4d [PATCH] umount_tr... |
1287 |
{ |
a3b3c5627 mnt: Use hlist_mo... |
1288 |
struct hlist_head head; |
97216be09 fold release_moun... |
1289 |
|
a3b3c5627 mnt: Use hlist_mo... |
1290 |
hlist_move_list(&unmounted, &head); |
97216be09 fold release_moun... |
1291 |
|
97216be09 fold release_moun... |
1292 |
up_write(&namespace_sem); |
a3b3c5627 mnt: Use hlist_mo... |
1293 1294 |
if (likely(hlist_empty(&head))) return; |
48a066e72 RCU'd vfsmounts |
1295 |
synchronize_rcu(); |
87b95ce09 switch the IO-tri... |
1296 |
group_pin_kill(&head); |
70fbcdf4d [PATCH] umount_tr... |
1297 |
} |
97216be09 fold release_moun... |
1298 |
static inline void namespace_lock(void) |
e3197d83d saner umount_tree... |
1299 |
{ |
97216be09 fold release_moun... |
1300 |
down_write(&namespace_sem); |
e3197d83d saner umount_tree... |
1301 |
} |
e819f1521 mnt: Improve the ... |
1302 1303 1304 |
enum umount_tree_flags { UMOUNT_SYNC = 1, UMOUNT_PROPAGATE = 2, |
e0c9c0afd mnt: Update detac... |
1305 |
UMOUNT_CONNECTED = 4, |
e819f1521 mnt: Improve the ... |
1306 |
}; |
f2d0a123b mnt: Clarify and ... |
1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 |
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... |
1336 |
/* |
48a066e72 RCU'd vfsmounts |
1337 |
* mount_lock must be held |
99b7db7b8 fs: brlock vfsmou... |
1338 1339 |
* namespace_sem must be held for write */ |
e819f1521 mnt: Improve the ... |
1340 |
static void umount_tree(struct mount *mnt, enum umount_tree_flags how) |
1da177e4c Linux-2.6.12-rc2 |
1341 |
{ |
c003b26ff mnt: In umount_tr... |
1342 |
LIST_HEAD(tmp_list); |
315fc83e5 vfs: spread struc... |
1343 |
struct mount *p; |
1da177e4c Linux-2.6.12-rc2 |
1344 |
|
5d88457eb mnt: On an unmoun... |
1345 1346 |
if (how & UMOUNT_PROPAGATE) propagate_mount_unlock(mnt); |
c003b26ff mnt: In umount_tr... |
1347 |
/* Gather the mounts to umount */ |
590ce4bcb mnt: Add MNT_UMOU... |
1348 1349 |
for (p = mnt; p; p = next_mnt(p, mnt)) { p->mnt.mnt_flags |= MNT_UMOUNT; |
c003b26ff mnt: In umount_tr... |
1350 |
list_move(&p->mnt_list, &tmp_list); |
590ce4bcb mnt: Add MNT_UMOU... |
1351 |
} |
1da177e4c Linux-2.6.12-rc2 |
1352 |
|
411a938b5 mnt: Delay remova... |
1353 |
/* Hide the mounts from mnt_mounts */ |
c003b26ff mnt: In umount_tr... |
1354 |
list_for_each_entry(p, &tmp_list, mnt_list) { |
88b368f27 get rid of propag... |
1355 |
list_del_init(&p->mnt_child); |
c003b26ff mnt: In umount_tr... |
1356 |
} |
88b368f27 get rid of propag... |
1357 |
|
c003b26ff mnt: In umount_tr... |
1358 |
/* Add propogated mounts to the tmp_list */ |
e819f1521 mnt: Improve the ... |
1359 |
if (how & UMOUNT_PROPAGATE) |
7b8a53fd8 fix old umount_tr... |
1360 |
propagate_umount(&tmp_list); |
a05964f39 [PATCH] shared mo... |
1361 |
|
c003b26ff mnt: In umount_tr... |
1362 |
while (!list_empty(&tmp_list)) { |
d29216842 mnt: Add a per mo... |
1363 |
struct mnt_namespace *ns; |
ce07d891a mnt: Honor MNT_LO... |
1364 |
bool disconnect; |
c003b26ff mnt: In umount_tr... |
1365 |
p = list_first_entry(&tmp_list, struct mount, mnt_list); |
6776db3d3 vfs: take mnt_sha... |
1366 |
list_del_init(&p->mnt_expire); |
1a4eeaf2a vfs: move mnt_lis... |
1367 |
list_del_init(&p->mnt_list); |
d29216842 mnt: Add a per mo... |
1368 1369 1370 1371 1372 |
ns = p->mnt_ns; if (ns) { ns->mounts--; __touch_mnt_namespace(ns); } |
143c8c91c vfs: mnt_ns moved... |
1373 |
p->mnt_ns = NULL; |
e819f1521 mnt: Improve the ... |
1374 |
if (how & UMOUNT_SYNC) |
48a066e72 RCU'd vfsmounts |
1375 |
p->mnt.mnt_flags |= MNT_SYNC_UMOUNT; |
87b95ce09 switch the IO-tri... |
1376 |
|
f2d0a123b mnt: Clarify and ... |
1377 |
disconnect = disconnect_mount(p, how); |
ce07d891a mnt: Honor MNT_LO... |
1378 1379 1380 |
pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt, disconnect ? &unmounted : NULL); |
676da58df vfs: spread struc... |
1381 |
if (mnt_has_parent(p)) { |
81b6b0619 fix EBUSY on umou... |
1382 |
mnt_add_count(p->mnt_parent, -1); |
ce07d891a mnt: Honor MNT_LO... |
1383 1384 1385 1386 1387 1388 |
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... |
1389 |
} |
0f0afb1dc vfs: spread struc... |
1390 |
change_mnt_propagation(p, MS_PRIVATE); |
1da177e4c Linux-2.6.12-rc2 |
1391 1392 |
} } |
b54b9be78 get rid of the se... |
1393 |
static void shrink_submounts(struct mount *mnt); |
c35038bec [PATCH] do shrink... |
1394 |
|
1ab597386 vfs: spread struc... |
1395 |
static int do_umount(struct mount *mnt, int flags) |
1da177e4c Linux-2.6.12-rc2 |
1396 |
{ |
1ab597386 vfs: spread struc... |
1397 |
struct super_block *sb = mnt->mnt.mnt_sb; |
1da177e4c Linux-2.6.12-rc2 |
1398 |
int retval; |
1ab597386 vfs: spread struc... |
1399 |
retval = security_sb_umount(&mnt->mnt, flags); |
1da177e4c Linux-2.6.12-rc2 |
1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 |
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... |
1410 |
if (&mnt->mnt == current->fs->root.mnt || |
1da177e4c Linux-2.6.12-rc2 |
1411 1412 |
flags & (MNT_FORCE | MNT_DETACH)) return -EINVAL; |
b3e19d924 fs: scale mntget/... |
1413 1414 1415 1416 |
/* * probably don't strictly need the lock here if we examined * all race cases, but it's a slowpath. */ |
719ea2fbb new helpers: lock... |
1417 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
1418 |
if (mnt_get_count(mnt) != 2) { |
719ea2fbb new helpers: lock... |
1419 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1420 |
return -EBUSY; |
b3e19d924 fs: scale mntget/... |
1421 |
} |
719ea2fbb new helpers: lock... |
1422 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1423 |
|
863d684f9 vfs: move the res... |
1424 |
if (!xchg(&mnt->mnt_expiry_mark, 1)) |
1da177e4c Linux-2.6.12-rc2 |
1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 |
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... |
1437 |
if (flags & MNT_FORCE && sb->s_op->umount_begin) { |
42faad996 [PATCH] restore s... |
1438 |
sb->s_op->umount_begin(sb); |
42faad996 [PATCH] restore s... |
1439 |
} |
1da177e4c Linux-2.6.12-rc2 |
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 |
/* * 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... |
1450 |
if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) { |
1da177e4c Linux-2.6.12-rc2 |
1451 1452 1453 1454 |
/* * Special case for "unmounting" root ... * we just try to remount it readonly. */ |
bc6155d13 fs: Allow superbl... |
1455 |
if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) |
a1480dcc3 fs: Add a missing... |
1456 |
return -EPERM; |
1da177e4c Linux-2.6.12-rc2 |
1457 |
down_write(&sb->s_umount); |
bc98a42c1 VFS: Convert sb->... |
1458 |
if (!sb_rdonly(sb)) |
e462ec50c VFS: Differentiat... |
1459 |
retval = do_remount_sb(sb, SB_RDONLY, NULL, 0); |
1da177e4c Linux-2.6.12-rc2 |
1460 1461 1462 |
up_write(&sb->s_umount); return retval; } |
97216be09 fold release_moun... |
1463 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
1464 |
lock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1465 |
|
32224b874 mount: Retest MNT... |
1466 1467 1468 1469 1470 1471 |
/* Recheck MNT_LOCKED with the locks held */ retval = -EINVAL; if (mnt->mnt.mnt_flags & MNT_LOCKED) goto out; event++; |
48a066e72 RCU'd vfsmounts |
1472 |
if (flags & MNT_DETACH) { |
1a4eeaf2a vfs: move mnt_lis... |
1473 |
if (!list_empty(&mnt->mnt_list)) |
e819f1521 mnt: Improve the ... |
1474 |
umount_tree(mnt, UMOUNT_PROPAGATE); |
1da177e4c Linux-2.6.12-rc2 |
1475 |
retval = 0; |
48a066e72 RCU'd vfsmounts |
1476 1477 1478 1479 1480 |
} else { shrink_submounts(mnt); retval = -EBUSY; if (!propagate_mount_busy(mnt, 2)) { if (!list_empty(&mnt->mnt_list)) |
e819f1521 mnt: Improve the ... |
1481 |
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
48a066e72 RCU'd vfsmounts |
1482 1483 |
retval = 0; } |
1da177e4c Linux-2.6.12-rc2 |
1484 |
} |
32224b874 mount: Retest MNT... |
1485 |
out: |
719ea2fbb new helpers: lock... |
1486 |
unlock_mount_hash(); |
e3197d83d saner umount_tree... |
1487 |
namespace_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1488 1489 |
return retval; } |
80b5dce8c vfs: Add a functi... |
1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 |
/* * __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 ... |
1506 |
lock_mount_hash(); |
80b5dce8c vfs: Add a functi... |
1507 |
mp = lookup_mountpoint(dentry); |
f53e57975 mnt: Fix the erro... |
1508 |
if (IS_ERR_OR_NULL(mp)) |
80b5dce8c vfs: Add a functi... |
1509 |
goto out_unlock; |
e06b933e6 namespace: update... |
1510 |
event++; |
80b5dce8c vfs: Add a functi... |
1511 1512 |
while (!hlist_empty(&mp->m_list)) { mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list); |
ce07d891a mnt: Honor MNT_LO... |
1513 |
if (mnt->mnt.mnt_flags & MNT_UMOUNT) { |
fe78fcc85 mnt: In detach_mo... |
1514 1515 |
hlist_add_head(&mnt->mnt_umount.s_list, &unmounted); umount_mnt(mnt); |
ce07d891a mnt: Honor MNT_LO... |
1516 |
} |
e0c9c0afd mnt: Update detac... |
1517 |
else umount_tree(mnt, UMOUNT_CONNECTED); |
80b5dce8c vfs: Add a functi... |
1518 |
} |
80b5dce8c vfs: Add a functi... |
1519 1520 |
put_mountpoint(mp); out_unlock: |
3895dbf89 mnt: Protect the ... |
1521 |
unlock_mount_hash(); |
80b5dce8c vfs: Add a functi... |
1522 1523 |
namespace_unlock(); } |
dd111b31e VFS: Clean up whi... |
1524 |
/* |
9b40bc90a get rid of unprot... |
1525 1526 1527 1528 1529 1530 |
* 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); } |
9e8925b67 locks: Allow disa... |
1531 1532 1533 1534 1535 |
static inline bool may_mandlock(void) { #ifndef CONFIG_MANDATORY_FILE_LOCKING return false; #endif |
95ace7541 locks: Don't allo... |
1536 |
return capable(CAP_SYS_ADMIN); |
9e8925b67 locks: Allow disa... |
1537 |
} |
1da177e4c Linux-2.6.12-rc2 |
1538 1539 1540 1541 1542 1543 1544 |
/* * 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... |
1545 |
int ksys_umount(char __user *name, int flags) |
1da177e4c Linux-2.6.12-rc2 |
1546 |
{ |
2d8f30380 [PATCH] sanitize ... |
1547 |
struct path path; |
900148dca vfs: spread struc... |
1548 |
struct mount *mnt; |
1da177e4c Linux-2.6.12-rc2 |
1549 |
int retval; |
db1f05bb8 vfs: add NOFOLLOW... |
1550 |
int lookup_flags = 0; |
1da177e4c Linux-2.6.12-rc2 |
1551 |
|
db1f05bb8 vfs: add NOFOLLOW... |
1552 1553 |
if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW)) return -EINVAL; |
9b40bc90a get rid of unprot... |
1554 1555 |
if (!may_mount()) return -EPERM; |
db1f05bb8 vfs: add NOFOLLOW... |
1556 1557 |
if (!(flags & UMOUNT_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; |
197df04c7 rename user_path_... |
1558 |
retval = user_path_mountpoint_at(AT_FDCWD, name, lookup_flags, &path); |
1da177e4c Linux-2.6.12-rc2 |
1559 1560 |
if (retval) goto out; |
900148dca vfs: spread struc... |
1561 |
mnt = real_mount(path.mnt); |
1da177e4c Linux-2.6.12-rc2 |
1562 |
retval = -EINVAL; |
2d8f30380 [PATCH] sanitize ... |
1563 |
if (path.dentry != path.mnt->mnt_root) |
1da177e4c Linux-2.6.12-rc2 |
1564 |
goto dput_and_out; |
143c8c91c vfs: mnt_ns moved... |
1565 |
if (!check_mnt(mnt)) |
1da177e4c Linux-2.6.12-rc2 |
1566 |
goto dput_and_out; |
32224b874 mount: Retest MNT... |
1567 |
if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */ |
5ff9d8a65 vfs: Lock in plac... |
1568 |
goto dput_and_out; |
b2f5d4dc3 umount: Disallow ... |
1569 1570 1571 |
retval = -EPERM; if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN)) goto dput_and_out; |
1da177e4c Linux-2.6.12-rc2 |
1572 |
|
900148dca vfs: spread struc... |
1573 |
retval = do_umount(mnt, flags); |
1da177e4c Linux-2.6.12-rc2 |
1574 |
dput_and_out: |
429731b15 Remove path_relea... |
1575 |
/* we mustn't call path_put() as that would clear mnt_expiry_mark */ |
2d8f30380 [PATCH] sanitize ... |
1576 |
dput(path.dentry); |
900148dca vfs: spread struc... |
1577 |
mntput_no_expire(mnt); |
1da177e4c Linux-2.6.12-rc2 |
1578 1579 1580 |
out: return retval; } |
3a18ef5c1 fs: add ksys_umou... |
1581 1582 1583 1584 |
SYSCALL_DEFINE2(umount, char __user *, name, int, flags) { return ksys_umount(name, flags); } |
1da177e4c Linux-2.6.12-rc2 |
1585 1586 1587 |
#ifdef __ARCH_WANT_SYS_OLDUMOUNT /* |
b58fed8b1 [PATCH] lindent f... |
1588 |
* The 2.0 compatible umount. No flags. |
1da177e4c Linux-2.6.12-rc2 |
1589 |
*/ |
bdc480e3b [CVE-2009-0029] S... |
1590 |
SYSCALL_DEFINE1(oldumount, char __user *, name) |
1da177e4c Linux-2.6.12-rc2 |
1591 |
{ |
3a18ef5c1 fs: add ksys_umou... |
1592 |
return ksys_umount(name, 0); |
1da177e4c Linux-2.6.12-rc2 |
1593 1594 1595 |
} #endif |
4ce5d2b1a vfs: Don't copy m... |
1596 |
static bool is_mnt_ns_file(struct dentry *dentry) |
8823c079b vfs: Add setns su... |
1597 |
{ |
4ce5d2b1a vfs: Don't copy m... |
1598 |
/* Is this a proxy for a mount namespace? */ |
e149ed2b8 take the targets ... |
1599 1600 |
return dentry->d_op == &ns_dentry_operations && dentry->d_fsdata == &mntns_operations; |
4ce5d2b1a vfs: Don't copy m... |
1601 |
} |
58be28256 make mntns ->get(... |
1602 1603 1604 1605 |
struct mnt_namespace *to_mnt_ns(struct ns_common *ns) { return container_of(ns, struct mnt_namespace, ns); } |
4ce5d2b1a vfs: Don't copy m... |
1606 1607 1608 1609 1610 1611 1612 1613 |
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_... |
1614 |
mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode)); |
8823c079b vfs: Add setns su... |
1615 1616 |
return current->nsproxy->mnt_ns->seq >= mnt_ns->seq; } |
87129cc0e vfs: spread struc... |
1617 |
struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, |
36341f645 [PATCH] mount exp... |
1618 |
int flag) |
1da177e4c Linux-2.6.12-rc2 |
1619 |
{ |
84d17192d get rid of full-h... |
1620 |
struct mount *res, *p, *q, *r, *parent; |
1da177e4c Linux-2.6.12-rc2 |
1621 |
|
4ce5d2b1a vfs: Don't copy m... |
1622 1623 1624 1625 |
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... |
1626 |
return ERR_PTR(-EINVAL); |
9676f0c63 [PATCH] unbindabl... |
1627 |
|
36341f645 [PATCH] mount exp... |
1628 |
res = q = clone_mnt(mnt, dentry, flag); |
be34d1a3b VFS: Make clone_m... |
1629 1630 |
if (IS_ERR(q)) return q; |
a73324da7 vfs: move mnt_mou... |
1631 |
q->mnt_mountpoint = mnt->mnt_mountpoint; |
1da177e4c Linux-2.6.12-rc2 |
1632 1633 |
p = mnt; |
6b41d536f vfs: take mnt_chi... |
1634 |
list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) { |
315fc83e5 vfs: spread struc... |
1635 |
struct mount *s; |
7ec02ef15 vfs: remove lives... |
1636 |
if (!is_subdir(r->mnt_mountpoint, dentry)) |
1da177e4c Linux-2.6.12-rc2 |
1637 |
continue; |
909b0a88e vfs: spread struc... |
1638 |
for (s = r; s; s = next_mnt(s, r)) { |
4ce5d2b1a vfs: Don't copy m... |
1639 1640 |
if (!(flag & CL_COPY_UNBINDABLE) && IS_MNT_UNBINDABLE(s)) { |
14e4bec18 mount: Don't allo... |
1641 1642 1643 1644 1645 1646 1647 1648 |
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... |
1649 1650 1651 |
} if (!(flag & CL_COPY_MNT_NS_FILE) && is_mnt_ns_file(s->mnt.mnt_root)) { |
9676f0c63 [PATCH] unbindabl... |
1652 1653 1654 |
s = skip_mnt_tree(s); continue; } |
0714a5338 vfs: now it can b... |
1655 1656 1657 |
while (p != s->mnt_parent) { p = p->mnt_parent; q = q->mnt_parent; |
1da177e4c Linux-2.6.12-rc2 |
1658 |
} |
87129cc0e vfs: spread struc... |
1659 |
p = s; |
84d17192d get rid of full-h... |
1660 |
parent = q; |
87129cc0e vfs: spread struc... |
1661 |
q = clone_mnt(p, p->mnt.mnt_root, flag); |
be34d1a3b VFS: Make clone_m... |
1662 1663 |
if (IS_ERR(q)) goto out; |
719ea2fbb new helpers: lock... |
1664 |
lock_mount_hash(); |
1a4eeaf2a vfs: move mnt_lis... |
1665 |
list_add_tail(&q->mnt_list, &res->mnt_list); |
1064f874a mnt: Tuck mounts ... |
1666 |
attach_mnt(q, parent, p->mnt_mp); |
719ea2fbb new helpers: lock... |
1667 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1668 1669 1670 |
} } return res; |
be34d1a3b VFS: Make clone_m... |
1671 |
out: |
1da177e4c Linux-2.6.12-rc2 |
1672 |
if (res) { |
719ea2fbb new helpers: lock... |
1673 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
1674 |
umount_tree(res, UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
1675 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1676 |
} |
be34d1a3b VFS: Make clone_m... |
1677 |
return q; |
1da177e4c Linux-2.6.12-rc2 |
1678 |
} |
be34d1a3b VFS: Make clone_m... |
1679 |
/* Caller should check returned pointer for errors */ |
ca71cf71e namespace.c: cons... |
1680 |
struct vfsmount *collect_mounts(const struct path *path) |
8aec08094 [PATCH] new helpe... |
1681 |
{ |
cb338d06e vfs: spread struc... |
1682 |
struct mount *tree; |
97216be09 fold release_moun... |
1683 |
namespace_lock(); |
cd4a40174 mnt: Fail collect... |
1684 1685 1686 1687 1688 |
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... |
1689 |
namespace_unlock(); |
be34d1a3b VFS: Make clone_m... |
1690 |
if (IS_ERR(tree)) |
52e220d35 VFS: collect_moun... |
1691 |
return ERR_CAST(tree); |
be34d1a3b VFS: Make clone_m... |
1692 |
return &tree->mnt; |
8aec08094 [PATCH] new helpe... |
1693 1694 1695 1696 |
} void drop_collected_mounts(struct vfsmount *mnt) { |
97216be09 fold release_moun... |
1697 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
1698 |
lock_mount_hash(); |
a7861ef89 mount: Prevent MN... |
1699 |
umount_tree(real_mount(mnt), 0); |
719ea2fbb new helpers: lock... |
1700 |
unlock_mount_hash(); |
3ab6abee5 more conversions ... |
1701 |
namespace_unlock(); |
8aec08094 [PATCH] new helpe... |
1702 |
} |
c771d683a vfs: introduce cl... |
1703 1704 1705 1706 1707 1708 1709 1710 1711 |
/** * 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... |
1712 |
struct vfsmount *clone_private_mount(const struct path *path) |
c771d683a vfs: introduce cl... |
1713 1714 1715 1716 1717 1718 |
{ 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... |
1719 |
new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE); |
c771d683a vfs: introduce cl... |
1720 1721 1722 1723 1724 1725 |
if (IS_ERR(new_mnt)) return ERR_CAST(new_mnt); return &new_mnt->mnt; } EXPORT_SYMBOL_GPL(clone_private_mount); |
1f707137b new helper: itera... |
1726 1727 1728 |
int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, struct vfsmount *root) { |
1a4eeaf2a vfs: move mnt_lis... |
1729 |
struct mount *mnt; |
1f707137b new helper: itera... |
1730 1731 1732 |
int res = f(root, arg); if (res) return res; |
1a4eeaf2a vfs: move mnt_lis... |
1733 1734 |
list_for_each_entry(mnt, &real_mount(root)->mnt_list, mnt_list) { res = f(&mnt->mnt, arg); |
1f707137b new helper: itera... |
1735 1736 1737 1738 1739 |
if (res) return res; } return 0; } |
4b8b21f4f vfs: spread struc... |
1740 |
static void cleanup_group_ids(struct mount *mnt, struct mount *end) |
719f5d7f0 [patch 4/7] vfs: ... |
1741 |
{ |
315fc83e5 vfs: spread struc... |
1742 |
struct mount *p; |
719f5d7f0 [patch 4/7] vfs: ... |
1743 |
|
909b0a88e vfs: spread struc... |
1744 |
for (p = mnt; p != end; p = next_mnt(p, mnt)) { |
fc7be130c vfs: switch pnode... |
1745 |
if (p->mnt_group_id && !IS_MNT_SHARED(p)) |
4b8b21f4f vfs: spread struc... |
1746 |
mnt_release_group_id(p); |
719f5d7f0 [patch 4/7] vfs: ... |
1747 1748 |
} } |
4b8b21f4f vfs: spread struc... |
1749 |
static int invent_group_ids(struct mount *mnt, bool recurse) |
719f5d7f0 [patch 4/7] vfs: ... |
1750 |
{ |
315fc83e5 vfs: spread struc... |
1751 |
struct mount *p; |
719f5d7f0 [patch 4/7] vfs: ... |
1752 |
|
909b0a88e vfs: spread struc... |
1753 |
for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) { |
fc7be130c vfs: switch pnode... |
1754 |
if (!p->mnt_group_id && !IS_MNT_SHARED(p)) { |
4b8b21f4f vfs: spread struc... |
1755 |
int err = mnt_alloc_group_id(p); |
719f5d7f0 [patch 4/7] vfs: ... |
1756 |
if (err) { |
4b8b21f4f vfs: spread struc... |
1757 |
cleanup_group_ids(mnt, p); |
719f5d7f0 [patch 4/7] vfs: ... |
1758 1759 1760 1761 1762 1763 1764 |
return err; } } } return 0; } |
d29216842 mnt: Add a per mo... |
1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 |
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... |
1786 1787 |
/* * @source_mnt : mount tree to be attached |
214444032 [PATCH] shared mo... |
1788 1789 1790 1791 |
* @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... |
1792 1793 1794 |
* * 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... |
1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 |
* --------------------------------------------------------------------------- * | 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... |
1807 1808 1809 1810 1811 1812 1813 1814 1815 |
* 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 ... |
1816 1817 1818 1819 1820 1821 1822 |
* (+++) 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... |
1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 |
* --------------------------------------------------------------------------- * | MOVE MOUNT OPERATION | * |************************************************************************** * | source-->| shared | private | slave | unbindable | * | dest | | | | | * | | | | | | | * | v | | | | | * |************************************************************************** * | shared | shared (+) | shared (+) | shared(+++) | invalid | * | | | | | | * |non-shared| shared (+*) | private | slave (*) | unbindable | * *************************************************************************** |
5afe00221 [PATCH] handling ... |
1835 1836 1837 |
* * (+) 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... |
1838 |
* (+*) the mount is moved to the destination. |
5afe00221 [PATCH] handling ... |
1839 1840 1841 1842 |
* (+++) 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... |
1843 1844 1845 1846 1847 1848 |
* * 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... |
1849 |
static int attach_recursive_mnt(struct mount *source_mnt, |
84d17192d get rid of full-h... |
1850 1851 1852 |
struct mount *dest_mnt, struct mountpoint *dest_mp, struct path *parent_path) |
b90fa9ae8 [PATCH] shared mo... |
1853 |
{ |
38129a13e switch mnt_hash t... |
1854 |
HLIST_HEAD(tree_list); |
d29216842 mnt: Add a per mo... |
1855 |
struct mnt_namespace *ns = dest_mnt->mnt_ns; |
1064f874a mnt: Tuck mounts ... |
1856 |
struct mountpoint *smp; |
315fc83e5 vfs: spread struc... |
1857 |
struct mount *child, *p; |
38129a13e switch mnt_hash t... |
1858 |
struct hlist_node *n; |
719f5d7f0 [patch 4/7] vfs: ... |
1859 |
int err; |
b90fa9ae8 [PATCH] shared mo... |
1860 |
|
1064f874a mnt: Tuck mounts ... |
1861 1862 1863 1864 1865 1866 |
/* 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... |
1867 1868 1869 1870 1871 1872 |
/* Is there space to add these mounts to the mount namespace? */ if (!parent_path) { err = count_mounts(ns, source_mnt); if (err) goto out; } |
fc7be130c vfs: switch pnode... |
1873 |
if (IS_MNT_SHARED(dest_mnt)) { |
0fb54e505 vfs: spread struc... |
1874 |
err = invent_group_ids(source_mnt, true); |
719f5d7f0 [patch 4/7] vfs: ... |
1875 1876 |
if (err) goto out; |
0b1b901b5 don't bother with... |
1877 |
err = propagate_mnt(dest_mnt, dest_mp, source_mnt, &tree_list); |
f2ebb3a92 smarter propagate... |
1878 |
lock_mount_hash(); |
0b1b901b5 don't bother with... |
1879 1880 |
if (err) goto out_cleanup_ids; |
909b0a88e vfs: spread struc... |
1881 |
for (p = source_mnt; p; p = next_mnt(p, source_mnt)) |
0f0afb1dc vfs: spread struc... |
1882 |
set_mnt_shared(p); |
0b1b901b5 don't bother with... |
1883 1884 |
} else { lock_mount_hash(); |
b90fa9ae8 [PATCH] shared mo... |
1885 |
} |
1a3906895 [PATCH] reduce st... |
1886 |
if (parent_path) { |
0fb54e505 vfs: spread struc... |
1887 |
detach_mnt(source_mnt, parent_path); |
84d17192d get rid of full-h... |
1888 |
attach_mnt(source_mnt, dest_mnt, dest_mp); |
143c8c91c vfs: mnt_ns moved... |
1889 |
touch_mnt_namespace(source_mnt->mnt_ns); |
214444032 [PATCH] shared mo... |
1890 |
} else { |
84d17192d get rid of full-h... |
1891 |
mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); |
1064f874a mnt: Tuck mounts ... |
1892 |
commit_tree(source_mnt); |
214444032 [PATCH] shared mo... |
1893 |
} |
b90fa9ae8 [PATCH] shared mo... |
1894 |
|
38129a13e switch mnt_hash t... |
1895 |
hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) { |
1d6a32acd keep shadowed vfs... |
1896 |
struct mount *q; |
38129a13e switch mnt_hash t... |
1897 |
hlist_del_init(&child->mnt_hash); |
1064f874a mnt: Tuck mounts ... |
1898 1899 1900 1901 1902 |
q = __lookup_mnt(&child->mnt_parent->mnt, child->mnt_mountpoint); if (q) mnt_change_mountpoint(child, smp, q); commit_tree(child); |
b90fa9ae8 [PATCH] shared mo... |
1903 |
} |
1064f874a mnt: Tuck mounts ... |
1904 |
put_mountpoint(smp); |
719ea2fbb new helpers: lock... |
1905 |
unlock_mount_hash(); |
99b7db7b8 fs: brlock vfsmou... |
1906 |
|
b90fa9ae8 [PATCH] shared mo... |
1907 |
return 0; |
719f5d7f0 [patch 4/7] vfs: ... |
1908 1909 |
out_cleanup_ids: |
f2ebb3a92 smarter propagate... |
1910 1911 |
while (!hlist_empty(&tree_list)) { child = hlist_entry(tree_list.first, struct mount, mnt_hash); |
d29216842 mnt: Add a per mo... |
1912 |
child->mnt_parent->mnt_ns->pending_mounts = 0; |
e819f1521 mnt: Improve the ... |
1913 |
umount_tree(child, UMOUNT_SYNC); |
f2ebb3a92 smarter propagate... |
1914 1915 |
} unlock_mount_hash(); |
0b1b901b5 don't bother with... |
1916 |
cleanup_group_ids(source_mnt, NULL); |
719f5d7f0 [patch 4/7] vfs: ... |
1917 |
out: |
d29216842 mnt: Add a per mo... |
1918 |
ns->pending_mounts = 0; |
1064f874a mnt: Tuck mounts ... |
1919 1920 1921 1922 |
read_seqlock_excl(&mount_lock); put_mountpoint(smp); read_sequnlock_excl(&mount_lock); |
719f5d7f0 [patch 4/7] vfs: ... |
1923 |
return err; |
b90fa9ae8 [PATCH] shared mo... |
1924 |
} |
84d17192d get rid of full-h... |
1925 |
static struct mountpoint *lock_mount(struct path *path) |
b12cea919 change the lockin... |
1926 1927 |
{ struct vfsmount *mnt; |
84d17192d get rid of full-h... |
1928 |
struct dentry *dentry = path->dentry; |
b12cea919 change the lockin... |
1929 |
retry: |
5955102c9 wrappers for ->i_... |
1930 |
inode_lock(dentry->d_inode); |
84d17192d get rid of full-h... |
1931 |
if (unlikely(cant_mount(dentry))) { |
5955102c9 wrappers for ->i_... |
1932 |
inode_unlock(dentry->d_inode); |
84d17192d get rid of full-h... |
1933 |
return ERR_PTR(-ENOENT); |
b12cea919 change the lockin... |
1934 |
} |
97216be09 fold release_moun... |
1935 |
namespace_lock(); |
b12cea919 change the lockin... |
1936 |
mnt = lookup_mnt(path); |
84d17192d get rid of full-h... |
1937 |
if (likely(!mnt)) { |
3895dbf89 mnt: Protect the ... |
1938 |
struct mountpoint *mp = get_mountpoint(dentry); |
84d17192d get rid of full-h... |
1939 |
if (IS_ERR(mp)) { |
97216be09 fold release_moun... |
1940 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
1941 |
inode_unlock(dentry->d_inode); |
84d17192d get rid of full-h... |
1942 1943 1944 1945 |
return mp; } return mp; } |
97216be09 fold release_moun... |
1946 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
1947 |
inode_unlock(path->dentry->d_inode); |
b12cea919 change the lockin... |
1948 1949 |
path_put(path); path->mnt = mnt; |
84d17192d get rid of full-h... |
1950 |
dentry = path->dentry = dget(mnt->mnt_root); |
b12cea919 change the lockin... |
1951 1952 |
goto retry; } |
84d17192d get rid of full-h... |
1953 |
static void unlock_mount(struct mountpoint *where) |
b12cea919 change the lockin... |
1954 |
{ |
84d17192d get rid of full-h... |
1955 |
struct dentry *dentry = where->m_dentry; |
3895dbf89 mnt: Protect the ... |
1956 1957 |
read_seqlock_excl(&mount_lock); |
84d17192d get rid of full-h... |
1958 |
put_mountpoint(where); |
3895dbf89 mnt: Protect the ... |
1959 |
read_sequnlock_excl(&mount_lock); |
328e6d901 switch unlock_mou... |
1960 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
1961 |
inode_unlock(dentry->d_inode); |
b12cea919 change the lockin... |
1962 |
} |
84d17192d get rid of full-h... |
1963 |
static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp) |
1da177e4c Linux-2.6.12-rc2 |
1964 |
{ |
e462ec50c VFS: Differentiat... |
1965 |
if (mnt->mnt.mnt_sb->s_flags & SB_NOUSER) |
1da177e4c Linux-2.6.12-rc2 |
1966 |
return -EINVAL; |
e36cb0b89 VFS: (Scripted) C... |
1967 1968 |
if (d_is_dir(mp->m_dentry) != d_is_dir(mnt->mnt.mnt_root)) |
1da177e4c Linux-2.6.12-rc2 |
1969 |
return -ENOTDIR; |
84d17192d get rid of full-h... |
1970 |
return attach_recursive_mnt(mnt, p, mp, NULL); |
1da177e4c Linux-2.6.12-rc2 |
1971 1972 1973 |
} /* |
7a2e8a8fa VFS: Sanity check... |
1974 1975 |
* Sanity check the flags to change_mnt_propagation. */ |
e462ec50c VFS: Differentiat... |
1976 |
static int flags_to_propagation_type(int ms_flags) |
7a2e8a8fa VFS: Sanity check... |
1977 |
{ |
e462ec50c VFS: Differentiat... |
1978 |
int type = ms_flags & ~(MS_REC | MS_SILENT); |
7a2e8a8fa VFS: Sanity check... |
1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 |
/* 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... |
1990 1991 |
* recursively change the type of the mountpoint. */ |
e462ec50c VFS: Differentiat... |
1992 |
static int do_change_type(struct path *path, int ms_flags) |
07b20889e [PATCH] beginning... |
1993 |
{ |
315fc83e5 vfs: spread struc... |
1994 |
struct mount *m; |
4b8b21f4f vfs: spread struc... |
1995 |
struct mount *mnt = real_mount(path->mnt); |
e462ec50c VFS: Differentiat... |
1996 |
int recurse = ms_flags & MS_REC; |
7a2e8a8fa VFS: Sanity check... |
1997 |
int type; |
719f5d7f0 [patch 4/7] vfs: ... |
1998 |
int err = 0; |
07b20889e [PATCH] beginning... |
1999 |
|
2d92ab3c6 [PATCH] finally g... |
2000 |
if (path->dentry != path->mnt->mnt_root) |
07b20889e [PATCH] beginning... |
2001 |
return -EINVAL; |
e462ec50c VFS: Differentiat... |
2002 |
type = flags_to_propagation_type(ms_flags); |
7a2e8a8fa VFS: Sanity check... |
2003 2004 |
if (!type) return -EINVAL; |
97216be09 fold release_moun... |
2005 |
namespace_lock(); |
719f5d7f0 [patch 4/7] vfs: ... |
2006 2007 2008 2009 2010 |
if (type == MS_SHARED) { err = invent_group_ids(mnt, recurse); if (err) goto out_unlock; } |
719ea2fbb new helpers: lock... |
2011 |
lock_mount_hash(); |
909b0a88e vfs: spread struc... |
2012 |
for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL)) |
0f0afb1dc vfs: spread struc... |
2013 |
change_mnt_propagation(m, type); |
719ea2fbb new helpers: lock... |
2014 |
unlock_mount_hash(); |
719f5d7f0 [patch 4/7] vfs: ... |
2015 2016 |
out_unlock: |
97216be09 fold release_moun... |
2017 |
namespace_unlock(); |
719f5d7f0 [patch 4/7] vfs: ... |
2018 |
return err; |
07b20889e [PATCH] beginning... |
2019 |
} |
5ff9d8a65 vfs: Lock in plac... |
2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 |
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; } |
07b20889e [PATCH] beginning... |
2032 |
/* |
1da177e4c Linux-2.6.12-rc2 |
2033 2034 |
* do loopback mount. */ |
808d4e3cf consitify do_moun... |
2035 |
static int do_loopback(struct path *path, const char *old_name, |
2dafe1c4d reduce large do_m... |
2036 |
int recurse) |
1da177e4c Linux-2.6.12-rc2 |
2037 |
{ |
2d92ab3c6 [PATCH] finally g... |
2038 |
struct path old_path; |
84d17192d get rid of full-h... |
2039 2040 |
struct mount *mnt = NULL, *old, *parent; struct mountpoint *mp; |
57eccb830 mount: consolidat... |
2041 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2042 2043 |
if (!old_name || !*old_name) return -EINVAL; |
815d405ce VFS: Fix the rema... |
2044 |
err = kern_path(old_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path); |
1da177e4c Linux-2.6.12-rc2 |
2045 2046 |
if (err) return err; |
8823c079b vfs: Add setns su... |
2047 |
err = -EINVAL; |
4ce5d2b1a vfs: Don't copy m... |
2048 |
if (mnt_ns_loop(old_path.dentry)) |
dd111b31e VFS: Clean up whi... |
2049 |
goto out; |
8823c079b vfs: Add setns su... |
2050 |
|
84d17192d get rid of full-h... |
2051 2052 2053 |
mp = lock_mount(path); err = PTR_ERR(mp); if (IS_ERR(mp)) |
b12cea919 change the lockin... |
2054 |
goto out; |
87129cc0e vfs: spread struc... |
2055 |
old = real_mount(old_path.mnt); |
84d17192d get rid of full-h... |
2056 |
parent = real_mount(path->mnt); |
87129cc0e vfs: spread struc... |
2057 |
|
1da177e4c Linux-2.6.12-rc2 |
2058 |
err = -EINVAL; |
fc7be130c vfs: switch pnode... |
2059 |
if (IS_MNT_UNBINDABLE(old)) |
b12cea919 change the lockin... |
2060 |
goto out2; |
9676f0c63 [PATCH] unbindabl... |
2061 |
|
e149ed2b8 take the targets ... |
2062 2063 2064 2065 |
if (!check_mnt(parent)) goto out2; if (!check_mnt(old) && old_path.dentry->d_op != &ns_dentry_operations) |
b12cea919 change the lockin... |
2066 |
goto out2; |
1da177e4c Linux-2.6.12-rc2 |
2067 |
|
5ff9d8a65 vfs: Lock in plac... |
2068 2069 |
if (!recurse && has_locked_children(old, old_path.dentry)) goto out2; |
ccd48bc7f [PATCH] cleanups ... |
2070 |
if (recurse) |
4ce5d2b1a vfs: Don't copy m... |
2071 |
mnt = copy_tree(old, old_path.dentry, CL_COPY_MNT_NS_FILE); |
ccd48bc7f [PATCH] cleanups ... |
2072 |
else |
87129cc0e vfs: spread struc... |
2073 |
mnt = clone_mnt(old, old_path.dentry, 0); |
ccd48bc7f [PATCH] cleanups ... |
2074 |
|
be34d1a3b VFS: Make clone_m... |
2075 2076 |
if (IS_ERR(mnt)) { err = PTR_ERR(mnt); |
e9c5d8a56 mnt: release lock... |
2077 |
goto out2; |
be34d1a3b VFS: Make clone_m... |
2078 |
} |
ccd48bc7f [PATCH] cleanups ... |
2079 |
|
5ff9d8a65 vfs: Lock in plac... |
2080 |
mnt->mnt.mnt_flags &= ~MNT_LOCKED; |
84d17192d get rid of full-h... |
2081 |
err = graft_tree(mnt, parent, mp); |
ccd48bc7f [PATCH] cleanups ... |
2082 |
if (err) { |
719ea2fbb new helpers: lock... |
2083 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
2084 |
umount_tree(mnt, UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
2085 |
unlock_mount_hash(); |
5b83d2c5c [PATCH] sanitize ... |
2086 |
} |
b12cea919 change the lockin... |
2087 |
out2: |
84d17192d get rid of full-h... |
2088 |
unlock_mount(mp); |
ccd48bc7f [PATCH] cleanups ... |
2089 |
out: |
2d92ab3c6 [PATCH] finally g... |
2090 |
path_put(&old_path); |
1da177e4c Linux-2.6.12-rc2 |
2091 2092 |
return err; } |
2e4b7fcd9 [PATCH] r/o bind ... |
2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 |
static int change_mount_flags(struct vfsmount *mnt, int ms_flags) { int error = 0; int readonly_request = 0; if (ms_flags & MS_RDONLY) readonly_request = 1; if (readonly_request == __mnt_is_readonly(mnt)) return 0; if (readonly_request) |
83adc7532 vfs: spread struc... |
2104 |
error = mnt_make_readonly(real_mount(mnt)); |
2e4b7fcd9 [PATCH] r/o bind ... |
2105 |
else |
83adc7532 vfs: spread struc... |
2106 |
__mnt_unmake_readonly(real_mount(mnt)); |
2e4b7fcd9 [PATCH] r/o bind ... |
2107 2108 |
return error; } |
1da177e4c Linux-2.6.12-rc2 |
2109 2110 2111 2112 2113 |
/* * 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... |
2114 2115 |
static int do_remount(struct path *path, int ms_flags, int sb_flags, int mnt_flags, void *data) |
1da177e4c Linux-2.6.12-rc2 |
2116 2117 |
{ int err; |
2d92ab3c6 [PATCH] finally g... |
2118 |
struct super_block *sb = path->mnt->mnt_sb; |
143c8c91c vfs: mnt_ns moved... |
2119 |
struct mount *mnt = real_mount(path->mnt); |
1da177e4c Linux-2.6.12-rc2 |
2120 |
|
143c8c91c vfs: mnt_ns moved... |
2121 |
if (!check_mnt(mnt)) |
1da177e4c Linux-2.6.12-rc2 |
2122 |
return -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2123 |
if (path->dentry != path->mnt->mnt_root) |
1da177e4c Linux-2.6.12-rc2 |
2124 |
return -EINVAL; |
07b645589 mnt: Move the tes... |
2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 |
/* Don't allow changing of locked mnt flags. * * 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. */ if ((mnt->mnt.mnt_flags & MNT_LOCK_READONLY) && !(mnt_flags & MNT_READONLY)) { return -EPERM; } |
9566d6742 mnt: Correct perm... |
2135 2136 |
if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) && !(mnt_flags & MNT_NODEV)) { |
67690f937 userns: Remove im... |
2137 |
return -EPERM; |
9566d6742 mnt: Correct perm... |
2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 |
} if ((mnt->mnt.mnt_flags & MNT_LOCK_NOSUID) && !(mnt_flags & MNT_NOSUID)) { return -EPERM; } if ((mnt->mnt.mnt_flags & MNT_LOCK_NOEXEC) && !(mnt_flags & MNT_NOEXEC)) { return -EPERM; } if ((mnt->mnt.mnt_flags & MNT_LOCK_ATIME) && ((mnt->mnt.mnt_flags & MNT_ATIME_MASK) != (mnt_flags & MNT_ATIME_MASK))) { return -EPERM; } |
ff36fe2c8 LSM: Pass -o remo... |
2151 2152 2153 |
err = security_sb_remount(sb, data); if (err) return err; |
1da177e4c Linux-2.6.12-rc2 |
2154 |
down_write(&sb->s_umount); |
e462ec50c VFS: Differentiat... |
2155 2156 |
if (ms_flags & MS_BIND) err = change_mount_flags(path->mnt, ms_flags); |
bc6155d13 fs: Allow superbl... |
2157 |
else if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) |
57eccb830 mount: consolidat... |
2158 |
err = -EPERM; |
4aa98cf76 Push BKL down int... |
2159 |
else |
e462ec50c VFS: Differentiat... |
2160 |
err = do_remount_sb(sb, sb_flags, data, 0); |
7b43a79f3 mnt_flags fixes i... |
2161 |
if (!err) { |
719ea2fbb new helpers: lock... |
2162 |
lock_mount_hash(); |
a6138db81 mnt: Only change ... |
2163 |
mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK; |
143c8c91c vfs: mnt_ns moved... |
2164 |
mnt->mnt.mnt_flags = mnt_flags; |
143c8c91c vfs: mnt_ns moved... |
2165 |
touch_mnt_namespace(mnt->mnt_ns); |
719ea2fbb new helpers: lock... |
2166 |
unlock_mount_hash(); |
0e55a7cca [RFC PATCH] touch... |
2167 |
} |
6339dab86 do_remount(): pul... |
2168 |
up_write(&sb->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
2169 2170 |
return err; } |
cbbe362cd vfs: spread struc... |
2171 |
static inline int tree_contains_unbindable(struct mount *mnt) |
9676f0c63 [PATCH] unbindabl... |
2172 |
{ |
315fc83e5 vfs: spread struc... |
2173 |
struct mount *p; |
909b0a88e vfs: spread struc... |
2174 |
for (p = mnt; p; p = next_mnt(p, mnt)) { |
fc7be130c vfs: switch pnode... |
2175 |
if (IS_MNT_UNBINDABLE(p)) |
9676f0c63 [PATCH] unbindabl... |
2176 2177 2178 2179 |
return 1; } return 0; } |
808d4e3cf consitify do_moun... |
2180 |
static int do_move_mount(struct path *path, const char *old_name) |
1da177e4c Linux-2.6.12-rc2 |
2181 |
{ |
2d92ab3c6 [PATCH] finally g... |
2182 |
struct path old_path, parent_path; |
676da58df vfs: spread struc... |
2183 |
struct mount *p; |
0fb54e505 vfs: spread struc... |
2184 |
struct mount *old; |
84d17192d get rid of full-h... |
2185 |
struct mountpoint *mp; |
57eccb830 mount: consolidat... |
2186 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2187 2188 |
if (!old_name || !*old_name) return -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2189 |
err = kern_path(old_name, LOOKUP_FOLLOW, &old_path); |
1da177e4c Linux-2.6.12-rc2 |
2190 2191 |
if (err) return err; |
84d17192d get rid of full-h... |
2192 2193 2194 |
mp = lock_mount(path); err = PTR_ERR(mp); if (IS_ERR(mp)) |
cc53ce53c Add a dentry op t... |
2195 |
goto out; |
143c8c91c vfs: mnt_ns moved... |
2196 |
old = real_mount(old_path.mnt); |
fc7be130c vfs: switch pnode... |
2197 |
p = real_mount(path->mnt); |
143c8c91c vfs: mnt_ns moved... |
2198 |
|
1da177e4c Linux-2.6.12-rc2 |
2199 |
err = -EINVAL; |
fc7be130c vfs: switch pnode... |
2200 |
if (!check_mnt(p) || !check_mnt(old)) |
1da177e4c Linux-2.6.12-rc2 |
2201 |
goto out1; |
5ff9d8a65 vfs: Lock in plac... |
2202 2203 |
if (old->mnt.mnt_flags & MNT_LOCKED) goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2204 |
err = -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2205 |
if (old_path.dentry != old_path.mnt->mnt_root) |
214444032 [PATCH] shared mo... |
2206 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2207 |
|
676da58df vfs: spread struc... |
2208 |
if (!mnt_has_parent(old)) |
214444032 [PATCH] shared mo... |
2209 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2210 |
|
e36cb0b89 VFS: (Scripted) C... |
2211 2212 |
if (d_is_dir(path->dentry) != d_is_dir(old_path.dentry)) |
214444032 [PATCH] shared mo... |
2213 2214 2215 2216 |
goto out1; /* * Don't move a mount residing in a shared parent. */ |
fc7be130c vfs: switch pnode... |
2217 |
if (IS_MNT_SHARED(old->mnt_parent)) |
214444032 [PATCH] shared mo... |
2218 |
goto out1; |
9676f0c63 [PATCH] unbindabl... |
2219 2220 2221 2222 |
/* * Don't move a mount tree containing unbindable mounts to a destination * mount which is shared. */ |
fc7be130c vfs: switch pnode... |
2223 |
if (IS_MNT_SHARED(p) && tree_contains_unbindable(old)) |
9676f0c63 [PATCH] unbindabl... |
2224 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2225 |
err = -ELOOP; |
fc7be130c vfs: switch pnode... |
2226 |
for (; mnt_has_parent(p); p = p->mnt_parent) |
676da58df vfs: spread struc... |
2227 |
if (p == old) |
214444032 [PATCH] shared mo... |
2228 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2229 |
|
84d17192d get rid of full-h... |
2230 |
err = attach_recursive_mnt(old, real_mount(path->mnt), mp, &parent_path); |
4ac913785 Embed a struct pa... |
2231 |
if (err) |
214444032 [PATCH] shared mo... |
2232 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2233 2234 2235 |
/* if the mount is moved, it should no longer be expire * automatically */ |
6776db3d3 vfs: take mnt_sha... |
2236 |
list_del_init(&old->mnt_expire); |
1da177e4c Linux-2.6.12-rc2 |
2237 |
out1: |
84d17192d get rid of full-h... |
2238 |
unlock_mount(mp); |
1da177e4c Linux-2.6.12-rc2 |
2239 |
out: |
1da177e4c Linux-2.6.12-rc2 |
2240 |
if (!err) |
1a3906895 [PATCH] reduce st... |
2241 |
path_put(&parent_path); |
2d92ab3c6 [PATCH] finally g... |
2242 |
path_put(&old_path); |
1da177e4c Linux-2.6.12-rc2 |
2243 2244 |
return err; } |
9d412a43c vfs: split off vf... |
2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 |
static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype) { int err; const char *subtype = strchr(fstype, '.'); if (subtype) { subtype++; err = -EINVAL; if (!subtype[0]) goto err; } else subtype = ""; mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL); err = -ENOMEM; if (!mnt->mnt_sb->s_subtype) goto err; return mnt; err: mntput(mnt); return ERR_PTR(err); } |
9d412a43c vfs: split off vf... |
2267 2268 2269 |
/* * add a mount into a namespace's mount tree */ |
95bc5f25c vfs: spread struc... |
2270 |
static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags) |
9d412a43c vfs: split off vf... |
2271 |
{ |
84d17192d get rid of full-h... |
2272 2273 |
struct mountpoint *mp; struct mount *parent; |
9d412a43c vfs: split off vf... |
2274 |
int err; |
f2ebb3a92 smarter propagate... |
2275 |
mnt_flags &= ~MNT_INTERNAL_FLAGS; |
9d412a43c vfs: split off vf... |
2276 |
|
84d17192d get rid of full-h... |
2277 2278 2279 |
mp = lock_mount(path); if (IS_ERR(mp)) return PTR_ERR(mp); |
9d412a43c vfs: split off vf... |
2280 |
|
84d17192d get rid of full-h... |
2281 |
parent = real_mount(path->mnt); |
9d412a43c vfs: split off vf... |
2282 |
err = -EINVAL; |
84d17192d get rid of full-h... |
2283 |
if (unlikely(!check_mnt(parent))) { |
156cacb1d do_add_mount()/um... |
2284 2285 2286 2287 |
/* 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... |
2288 |
if (!parent->mnt_ns) |
156cacb1d do_add_mount()/um... |
2289 2290 |
goto unlock; } |
9d412a43c vfs: split off vf... |
2291 2292 2293 |
/* Refuse the same filesystem on the same mount point */ err = -EBUSY; |
95bc5f25c vfs: spread struc... |
2294 |
if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb && |
9d412a43c vfs: split off vf... |
2295 2296 2297 2298 |
path->mnt->mnt_root == path->dentry) goto unlock; err = -EINVAL; |
e36cb0b89 VFS: (Scripted) C... |
2299 |
if (d_is_symlink(newmnt->mnt.mnt_root)) |
9d412a43c vfs: split off vf... |
2300 |
goto unlock; |
95bc5f25c vfs: spread struc... |
2301 |
newmnt->mnt.mnt_flags = mnt_flags; |
84d17192d get rid of full-h... |
2302 |
err = graft_tree(newmnt, parent, mp); |
9d412a43c vfs: split off vf... |
2303 2304 |
unlock: |
84d17192d get rid of full-h... |
2305 |
unlock_mount(mp); |
9d412a43c vfs: split off vf... |
2306 2307 |
return err; } |
b1e75df45 tidy up around fi... |
2308 |
|
8654df4e2 mnt: Refactor fs_... |
2309 |
static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags); |
1b852bceb mnt: Refactor the... |
2310 |
|
1da177e4c Linux-2.6.12-rc2 |
2311 2312 2313 2314 |
/* * create a new mount for userspace and request it to be added into the * namespace's tree */ |
e462ec50c VFS: Differentiat... |
2315 |
static int do_new_mount(struct path *path, const char *fstype, int sb_flags, |
808d4e3cf consitify do_moun... |
2316 |
int mnt_flags, const char *name, void *data) |
1da177e4c Linux-2.6.12-rc2 |
2317 |
{ |
0c55cfc41 vfs: Allow unpriv... |
2318 |
struct file_system_type *type; |
1da177e4c Linux-2.6.12-rc2 |
2319 |
struct vfsmount *mnt; |
15f9a3f3e don't drop newmnt... |
2320 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2321 |
|
0c55cfc41 vfs: Allow unpriv... |
2322 |
if (!fstype) |
1da177e4c Linux-2.6.12-rc2 |
2323 |
return -EINVAL; |
0c55cfc41 vfs: Allow unpriv... |
2324 2325 2326 |
type = get_fs_type(fstype); if (!type) return -ENODEV; |
e462ec50c VFS: Differentiat... |
2327 |
mnt = vfs_kern_mount(type, sb_flags, name, data); |
0c55cfc41 vfs: Allow unpriv... |
2328 2329 2330 2331 2332 |
if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) && !mnt->mnt_sb->s_subtype) mnt = fs_set_subtype(mnt, fstype); put_filesystem(type); |
1da177e4c Linux-2.6.12-rc2 |
2333 2334 |
if (IS_ERR(mnt)) return PTR_ERR(mnt); |
8654df4e2 mnt: Refactor fs_... |
2335 2336 2337 2338 |
if (mount_too_revealing(mnt, &mnt_flags)) { mntput(mnt); return -EPERM; } |
95bc5f25c vfs: spread struc... |
2339 |
err = do_add_mount(real_mount(mnt), path, mnt_flags); |
15f9a3f3e don't drop newmnt... |
2340 2341 2342 |
if (err) mntput(mnt); return err; |
1da177e4c Linux-2.6.12-rc2 |
2343 |
} |
19a167af7 Take the completi... |
2344 2345 |
int finish_automount(struct vfsmount *m, struct path *path) { |
6776db3d3 vfs: take mnt_sha... |
2346 |
struct mount *mnt = real_mount(m); |
19a167af7 Take the completi... |
2347 2348 2349 2350 |
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... |
2351 |
BUG_ON(mnt_get_count(mnt) < 2); |
19a167af7 Take the completi... |
2352 2353 2354 |
if (m->mnt_sb == path->mnt->mnt_sb && m->mnt_root == path->dentry) { |
b1e75df45 tidy up around fi... |
2355 2356 |
err = -ELOOP; goto fail; |
19a167af7 Take the completi... |
2357 |
} |
95bc5f25c vfs: spread struc... |
2358 |
err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE); |
b1e75df45 tidy up around fi... |
2359 2360 2361 2362 |
if (!err) return 0; fail: /* remove m from any expiration list it may be on */ |
6776db3d3 vfs: take mnt_sha... |
2363 |
if (!list_empty(&mnt->mnt_expire)) { |
97216be09 fold release_moun... |
2364 |
namespace_lock(); |
6776db3d3 vfs: take mnt_sha... |
2365 |
list_del_init(&mnt->mnt_expire); |
97216be09 fold release_moun... |
2366 |
namespace_unlock(); |
19a167af7 Take the completi... |
2367 |
} |
b1e75df45 tidy up around fi... |
2368 2369 |
mntput(m); mntput(m); |
19a167af7 Take the completi... |
2370 2371 |
return err; } |
ea5b778a8 Unexport do_add_m... |
2372 2373 2374 2375 2376 2377 2378 |
/** * 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... |
2379 |
namespace_lock(); |
ea5b778a8 Unexport do_add_m... |
2380 |
|
6776db3d3 vfs: take mnt_sha... |
2381 |
list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list); |
ea5b778a8 Unexport do_add_m... |
2382 |
|
97216be09 fold release_moun... |
2383 |
namespace_unlock(); |
ea5b778a8 Unexport do_add_m... |
2384 2385 2386 2387 |
} EXPORT_SYMBOL(mnt_set_expiry); /* |
1da177e4c Linux-2.6.12-rc2 |
2388 2389 2390 2391 2392 2393 |
* 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... |
2394 |
struct mount *mnt, *next; |
1da177e4c Linux-2.6.12-rc2 |
2395 2396 2397 2398 |
LIST_HEAD(graveyard); if (list_empty(mounts)) return; |
97216be09 fold release_moun... |
2399 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
2400 |
lock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
2401 2402 2403 2404 2405 2406 2407 |
/* 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... |
2408 |
list_for_each_entry_safe(mnt, next, mounts, mnt_expire) { |
863d684f9 vfs: move the res... |
2409 |
if (!xchg(&mnt->mnt_expiry_mark, 1) || |
1ab597386 vfs: spread struc... |
2410 |
propagate_mount_busy(mnt, 1)) |
1da177e4c Linux-2.6.12-rc2 |
2411 |
continue; |
6776db3d3 vfs: take mnt_sha... |
2412 |
list_move(&mnt->mnt_expire, &graveyard); |
1da177e4c Linux-2.6.12-rc2 |
2413 |
} |
bcc5c7d2b [PATCH] sanitize ... |
2414 |
while (!list_empty(&graveyard)) { |
6776db3d3 vfs: take mnt_sha... |
2415 |
mnt = list_first_entry(&graveyard, struct mount, mnt_expire); |
143c8c91c vfs: mnt_ns moved... |
2416 |
touch_mnt_namespace(mnt->mnt_ns); |
e819f1521 mnt: Improve the ... |
2417 |
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
bcc5c7d2b [PATCH] sanitize ... |
2418 |
} |
719ea2fbb new helpers: lock... |
2419 |
unlock_mount_hash(); |
3ab6abee5 more conversions ... |
2420 |
namespace_unlock(); |
5528f911b VFS: Add shrink_s... |
2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 |
} 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... |
2431 |
static int select_submounts(struct mount *parent, struct list_head *graveyard) |
5528f911b VFS: Add shrink_s... |
2432 |
{ |
692afc312 vfs: spread struc... |
2433 |
struct mount *this_parent = parent; |
5528f911b VFS: Add shrink_s... |
2434 2435 2436 2437 |
struct list_head *next; int found = 0; repeat: |
6b41d536f vfs: take mnt_chi... |
2438 |
next = this_parent->mnt_mounts.next; |
5528f911b VFS: Add shrink_s... |
2439 |
resume: |
6b41d536f vfs: take mnt_chi... |
2440 |
while (next != &this_parent->mnt_mounts) { |
5528f911b VFS: Add shrink_s... |
2441 |
struct list_head *tmp = next; |
6b41d536f vfs: take mnt_chi... |
2442 |
struct mount *mnt = list_entry(tmp, struct mount, mnt_child); |
5528f911b VFS: Add shrink_s... |
2443 2444 |
next = tmp->next; |
692afc312 vfs: spread struc... |
2445 |
if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE)) |
1da177e4c Linux-2.6.12-rc2 |
2446 |
continue; |
5528f911b VFS: Add shrink_s... |
2447 2448 2449 |
/* * Descend a level if the d_mounts list is non-empty. */ |
6b41d536f vfs: take mnt_chi... |
2450 |
if (!list_empty(&mnt->mnt_mounts)) { |
5528f911b VFS: Add shrink_s... |
2451 2452 2453 |
this_parent = mnt; goto repeat; } |
1da177e4c Linux-2.6.12-rc2 |
2454 |
|
1ab597386 vfs: spread struc... |
2455 |
if (!propagate_mount_busy(mnt, 1)) { |
6776db3d3 vfs: take mnt_sha... |
2456 |
list_move_tail(&mnt->mnt_expire, graveyard); |
5528f911b VFS: Add shrink_s... |
2457 2458 |
found++; } |
1da177e4c Linux-2.6.12-rc2 |
2459 |
} |
5528f911b VFS: Add shrink_s... |
2460 2461 2462 2463 |
/* * All done at this level ... ascend and resume the search */ if (this_parent != parent) { |
6b41d536f vfs: take mnt_chi... |
2464 |
next = this_parent->mnt_child.next; |
0714a5338 vfs: now it can b... |
2465 |
this_parent = this_parent->mnt_parent; |
5528f911b VFS: Add shrink_s... |
2466 2467 2468 2469 2470 2471 2472 2473 |
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... |
2474 |
* |
48a066e72 RCU'd vfsmounts |
2475 |
* mount_lock must be held for write |
5528f911b VFS: Add shrink_s... |
2476 |
*/ |
b54b9be78 get rid of the se... |
2477 |
static void shrink_submounts(struct mount *mnt) |
5528f911b VFS: Add shrink_s... |
2478 2479 |
{ LIST_HEAD(graveyard); |
761d5c38e vfs: spread struc... |
2480 |
struct mount *m; |
5528f911b VFS: Add shrink_s... |
2481 |
|
5528f911b VFS: Add shrink_s... |
2482 |
/* extract submounts of 'mountpoint' from the expiration list */ |
c35038bec [PATCH] do shrink... |
2483 |
while (select_submounts(mnt, &graveyard)) { |
bcc5c7d2b [PATCH] sanitize ... |
2484 |
while (!list_empty(&graveyard)) { |
761d5c38e vfs: spread struc... |
2485 |
m = list_first_entry(&graveyard, struct mount, |
6776db3d3 vfs: take mnt_sha... |
2486 |
mnt_expire); |
143c8c91c vfs: mnt_ns moved... |
2487 |
touch_mnt_namespace(m->mnt_ns); |
e819f1521 mnt: Improve the ... |
2488 |
umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
bcc5c7d2b [PATCH] sanitize ... |
2489 2490 |
} } |
1da177e4c Linux-2.6.12-rc2 |
2491 |
} |
1da177e4c Linux-2.6.12-rc2 |
2492 2493 2494 2495 2496 2497 |
/* * 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... |
2498 2499 |
static long exact_copy_from_user(void *to, const void __user * from, unsigned long n) |
1da177e4c Linux-2.6.12-rc2 |
2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 |
{ char *t = to; const char __user *f = from; char c; if (!access_ok(VERIFY_READ, from, n)) return n; while (n) { if (__get_user(c, f)) { memset(t, 0, n); break; } *t++ = c; f++; n--; } return n; } |
b40ef8696 saner calling con... |
2519 |
void *copy_mount_options(const void __user * data) |
1da177e4c Linux-2.6.12-rc2 |
2520 2521 |
{ int i; |
1da177e4c Linux-2.6.12-rc2 |
2522 |
unsigned long size; |
b40ef8696 saner calling con... |
2523 |
char *copy; |
b58fed8b1 [PATCH] lindent f... |
2524 |
|
1da177e4c Linux-2.6.12-rc2 |
2525 |
if (!data) |
b40ef8696 saner calling con... |
2526 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
2527 |
|
b40ef8696 saner calling con... |
2528 2529 2530 |
copy = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!copy) return ERR_PTR(-ENOMEM); |
1da177e4c Linux-2.6.12-rc2 |
2531 2532 2533 2534 2535 2536 2537 2538 2539 |
/* 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 ! */ size = TASK_SIZE - (unsigned long)data; if (size > PAGE_SIZE) size = PAGE_SIZE; |
b40ef8696 saner calling con... |
2540 |
i = size - exact_copy_from_user(copy, data, size); |
1da177e4c Linux-2.6.12-rc2 |
2541 |
if (!i) { |
b40ef8696 saner calling con... |
2542 2543 |
kfree(copy); return ERR_PTR(-EFAULT); |
1da177e4c Linux-2.6.12-rc2 |
2544 2545 |
} if (i != PAGE_SIZE) |
b40ef8696 saner calling con... |
2546 2547 |
memset(copy + i, 0, PAGE_SIZE - i); return copy; |
1da177e4c Linux-2.6.12-rc2 |
2548 |
} |
b8850d1fa fs: namespace: su... |
2549 |
char *copy_mount_string(const void __user *data) |
eca6f534e fs: fix overflow ... |
2550 |
{ |
b8850d1fa fs: namespace: su... |
2551 |
return data ? strndup_user(data, PAGE_SIZE) : NULL; |
eca6f534e fs: fix overflow ... |
2552 |
} |
1da177e4c Linux-2.6.12-rc2 |
2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 |
/* * 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... |
2567 |
long do_mount(const char *dev_name, const char __user *dir_name, |
808d4e3cf consitify do_moun... |
2568 |
const char *type_page, unsigned long flags, void *data_page) |
1da177e4c Linux-2.6.12-rc2 |
2569 |
{ |
2d92ab3c6 [PATCH] finally g... |
2570 |
struct path path; |
e462ec50c VFS: Differentiat... |
2571 |
unsigned int mnt_flags = 0, sb_flags; |
1da177e4c Linux-2.6.12-rc2 |
2572 |
int retval = 0; |
1da177e4c Linux-2.6.12-rc2 |
2573 2574 2575 2576 2577 2578 |
/* Discard magic */ if ((flags & MS_MGC_MSK) == MS_MGC_VAL) flags &= ~MS_MGC_MSK; /* Basic sanity checks */ |
1da177e4c Linux-2.6.12-rc2 |
2579 2580 |
if (data_page) ((char *)data_page)[PAGE_SIZE - 1] = 0; |
e462ec50c VFS: Differentiat... |
2581 2582 |
if (flags & MS_NOUSER) return -EINVAL; |
a27ab9f26 LSM: Pass origina... |
2583 |
/* ... and get the mountpoint */ |
5e6123f34 vfs: move getname... |
2584 |
retval = user_path(dir_name, &path); |
a27ab9f26 LSM: Pass origina... |
2585 2586 2587 2588 2589 |
if (retval) return retval; retval = security_sb_mount(dev_name, &path, type_page, flags, data_page); |
0d5cadb87 do_mount(): fix a... |
2590 2591 |
if (!retval && !may_mount()) retval = -EPERM; |
e462ec50c VFS: Differentiat... |
2592 |
if (!retval && (flags & SB_MANDLOCK) && !may_mandlock()) |
9e8925b67 locks: Allow disa... |
2593 |
retval = -EPERM; |
a27ab9f26 LSM: Pass origina... |
2594 2595 |
if (retval) goto dput_out; |
613cbe3d4 Don't set relatim... |
2596 2597 2598 |
/* Default to relatime unless overriden */ if (!(flags & MS_NOATIME)) mnt_flags |= MNT_RELATIME; |
0a1c01c94 Make relatime def... |
2599 |
|
1da177e4c Linux-2.6.12-rc2 |
2600 2601 2602 2603 2604 2605 2606 |
/* 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... |
2607 2608 2609 2610 |
if (flags & MS_NOATIME) mnt_flags |= MNT_NOATIME; if (flags & MS_NODIRATIME) mnt_flags |= MNT_NODIRATIME; |
d0adde574 Add a strictatime... |
2611 2612 |
if (flags & MS_STRICTATIME) mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME); |
a9e5b7328 vfs: Undo an over... |
2613 |
if (flags & MS_RDONLY) |
2e4b7fcd9 [PATCH] r/o bind ... |
2614 |
mnt_flags |= MNT_READONLY; |
fc33a7bb9 [PATCH] per-mount... |
2615 |
|
ffbc6f0ea mnt: Change the d... |
2616 2617 2618 2619 2620 2621 2622 |
/* 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... |
2623 2624 2625 2626 2627 |
sb_flags = flags & (SB_RDONLY | SB_SYNCHRONOUS | SB_MANDLOCK | SB_DIRSYNC | SB_SILENT | |
917086ff2 vfs: fix mounting... |
2628 |
SB_POSIXACL | |
d7ee94694 VFS: Handle lazyt... |
2629 |
SB_LAZYTIME | |
917086ff2 vfs: fix mounting... |
2630 |
SB_I_VERSION); |
1da177e4c Linux-2.6.12-rc2 |
2631 |
|
1da177e4c Linux-2.6.12-rc2 |
2632 |
if (flags & MS_REMOUNT) |
e462ec50c VFS: Differentiat... |
2633 |
retval = do_remount(&path, flags, sb_flags, mnt_flags, |
1da177e4c Linux-2.6.12-rc2 |
2634 2635 |
data_page); else if (flags & MS_BIND) |
2d92ab3c6 [PATCH] finally g... |
2636 |
retval = do_loopback(&path, dev_name, flags & MS_REC); |
9676f0c63 [PATCH] unbindabl... |
2637 |
else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) |
2d92ab3c6 [PATCH] finally g... |
2638 |
retval = do_change_type(&path, flags); |
1da177e4c Linux-2.6.12-rc2 |
2639 |
else if (flags & MS_MOVE) |
2d92ab3c6 [PATCH] finally g... |
2640 |
retval = do_move_mount(&path, dev_name); |
1da177e4c Linux-2.6.12-rc2 |
2641 |
else |
e462ec50c VFS: Differentiat... |
2642 |
retval = do_new_mount(&path, type_page, sb_flags, mnt_flags, |
1da177e4c Linux-2.6.12-rc2 |
2643 2644 |
dev_name, data_page); dput_out: |
2d92ab3c6 [PATCH] finally g... |
2645 |
path_put(&path); |
1da177e4c Linux-2.6.12-rc2 |
2646 2647 |
return retval; } |
537f7ccb3 mntns: Add a limi... |
2648 2649 2650 2651 2652 2653 2654 2655 2656 |
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... |
2657 2658 |
static void free_mnt_ns(struct mnt_namespace *ns) { |
6344c433a new helpers: ns_a... |
2659 |
ns_free_inum(&ns->ns); |
537f7ccb3 mntns: Add a limi... |
2660 |
dec_mnt_namespaces(ns->ucounts); |
771b13716 vfs: Add a user n... |
2661 2662 2663 |
put_user_ns(ns->user_ns); kfree(ns); } |
8823c079b vfs: Add setns su... |
2664 2665 2666 2667 2668 2669 2670 2671 |
/* * 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); |
771b13716 vfs: Add a user n... |
2672 |
static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) |
cf8d2c11c VFS: Add VFS help... |
2673 2674 |
{ struct mnt_namespace *new_ns; |
537f7ccb3 mntns: Add a limi... |
2675 |
struct ucounts *ucounts; |
98f842e67 proc: Usable inod... |
2676 |
int ret; |
cf8d2c11c VFS: Add VFS help... |
2677 |
|
537f7ccb3 mntns: Add a limi... |
2678 2679 |
ucounts = inc_mnt_namespaces(user_ns); if (!ucounts) |
df75e7748 userns: When the ... |
2680 |
return ERR_PTR(-ENOSPC); |
537f7ccb3 mntns: Add a limi... |
2681 |
|
cf8d2c11c VFS: Add VFS help... |
2682 |
new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); |
537f7ccb3 mntns: Add a limi... |
2683 2684 |
if (!new_ns) { dec_mnt_namespaces(ucounts); |
cf8d2c11c VFS: Add VFS help... |
2685 |
return ERR_PTR(-ENOMEM); |
537f7ccb3 mntns: Add a limi... |
2686 |
} |
6344c433a new helpers: ns_a... |
2687 |
ret = ns_alloc_inum(&new_ns->ns); |
98f842e67 proc: Usable inod... |
2688 2689 |
if (ret) { kfree(new_ns); |
537f7ccb3 mntns: Add a limi... |
2690 |
dec_mnt_namespaces(ucounts); |
98f842e67 proc: Usable inod... |
2691 2692 |
return ERR_PTR(ret); } |
33c429405 copy address of p... |
2693 |
new_ns->ns.ops = &mntns_operations; |
8823c079b vfs: Add setns su... |
2694 |
new_ns->seq = atomic64_add_return(1, &mnt_ns_seq); |
cf8d2c11c VFS: Add VFS help... |
2695 2696 2697 2698 2699 |
atomic_set(&new_ns->count, 1); new_ns->root = NULL; INIT_LIST_HEAD(&new_ns->list); init_waitqueue_head(&new_ns->poll); new_ns->event = 0; |
771b13716 vfs: Add a user n... |
2700 |
new_ns->user_ns = get_user_ns(user_ns); |
537f7ccb3 mntns: Add a limi... |
2701 |
new_ns->ucounts = ucounts; |
d29216842 mnt: Add a per mo... |
2702 2703 |
new_ns->mounts = 0; new_ns->pending_mounts = 0; |
cf8d2c11c VFS: Add VFS help... |
2704 2705 |
return new_ns; } |
0766f788e latent_entropy: M... |
2706 |
__latent_entropy |
9559f6891 fold dup_mnt_ns()... |
2707 2708 |
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 |
2709 |
{ |
6b3286ed1 [PATCH] rename st... |
2710 |
struct mnt_namespace *new_ns; |
7f2da1e7d [PATCH] kill altroot |
2711 |
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL; |
315fc83e5 vfs: spread struc... |
2712 |
struct mount *p, *q; |
9559f6891 fold dup_mnt_ns()... |
2713 |
struct mount *old; |
cb338d06e vfs: spread struc... |
2714 |
struct mount *new; |
7a472ef4b vfs: Only support... |
2715 |
int copy_flags; |
1da177e4c Linux-2.6.12-rc2 |
2716 |
|
9559f6891 fold dup_mnt_ns()... |
2717 2718 2719 2720 2721 2722 2723 2724 |
BUG_ON(!ns); if (likely(!(flags & CLONE_NEWNS))) { get_mnt_ns(ns); return ns; } old = ns->root; |
771b13716 vfs: Add a user n... |
2725 |
new_ns = alloc_mnt_ns(user_ns); |
cf8d2c11c VFS: Add VFS help... |
2726 2727 |
if (IS_ERR(new_ns)) return new_ns; |
1da177e4c Linux-2.6.12-rc2 |
2728 |
|
97216be09 fold release_moun... |
2729 |
namespace_lock(); |
1da177e4c Linux-2.6.12-rc2 |
2730 |
/* First pass: copy the tree topology */ |
4ce5d2b1a vfs: Don't copy m... |
2731 |
copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE; |
9559f6891 fold dup_mnt_ns()... |
2732 |
if (user_ns != ns->user_ns) |
132c94e31 vfs: Carefully pr... |
2733 |
copy_flags |= CL_SHARED_TO_SLAVE | CL_UNPRIVILEGED; |
7a472ef4b vfs: Only support... |
2734 |
new = copy_tree(old, old->mnt.mnt_root, copy_flags); |
be34d1a3b VFS: Make clone_m... |
2735 |
if (IS_ERR(new)) { |
328e6d901 switch unlock_mou... |
2736 |
namespace_unlock(); |
771b13716 vfs: Add a user n... |
2737 |
free_mnt_ns(new_ns); |
be34d1a3b VFS: Make clone_m... |
2738 |
return ERR_CAST(new); |
1da177e4c Linux-2.6.12-rc2 |
2739 |
} |
be08d6d26 switch mnt_namesp... |
2740 |
new_ns->root = new; |
1a4eeaf2a vfs: move mnt_lis... |
2741 |
list_add_tail(&new_ns->list, &new->mnt_list); |
1da177e4c Linux-2.6.12-rc2 |
2742 2743 2744 2745 2746 2747 |
/* * 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... |
2748 |
p = old; |
cb338d06e vfs: spread struc... |
2749 |
q = new; |
1da177e4c Linux-2.6.12-rc2 |
2750 |
while (p) { |
143c8c91c vfs: mnt_ns moved... |
2751 |
q->mnt_ns = new_ns; |
d29216842 mnt: Add a per mo... |
2752 |
new_ns->mounts++; |
9559f6891 fold dup_mnt_ns()... |
2753 2754 2755 |
if (new_fs) { if (&p->mnt == new_fs->root.mnt) { new_fs->root.mnt = mntget(&q->mnt); |
315fc83e5 vfs: spread struc... |
2756 |
rootmnt = &p->mnt; |
1da177e4c Linux-2.6.12-rc2 |
2757 |
} |
9559f6891 fold dup_mnt_ns()... |
2758 2759 |
if (&p->mnt == new_fs->pwd.mnt) { new_fs->pwd.mnt = mntget(&q->mnt); |
315fc83e5 vfs: spread struc... |
2760 |
pwdmnt = &p->mnt; |
1da177e4c Linux-2.6.12-rc2 |
2761 |
} |
1da177e4c Linux-2.6.12-rc2 |
2762 |
} |
909b0a88e vfs: spread struc... |
2763 2764 |
p = next_mnt(p, old); q = next_mnt(q, new); |
4ce5d2b1a vfs: Don't copy m... |
2765 2766 2767 2768 |
if (!q) break; while (p->mnt.mnt_root != q->mnt.mnt_root) p = next_mnt(p, old); |
1da177e4c Linux-2.6.12-rc2 |
2769 |
} |
328e6d901 switch unlock_mou... |
2770 |
namespace_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
2771 |
|
1da177e4c Linux-2.6.12-rc2 |
2772 |
if (rootmnt) |
f03c65993 sanitize vfsmount... |
2773 |
mntput(rootmnt); |
1da177e4c Linux-2.6.12-rc2 |
2774 |
if (pwdmnt) |
f03c65993 sanitize vfsmount... |
2775 |
mntput(pwdmnt); |
1da177e4c Linux-2.6.12-rc2 |
2776 |
|
741a29513 [PATCH] unshare s... |
2777 |
return new_ns; |
1da177e4c Linux-2.6.12-rc2 |
2778 |
} |
cf8d2c11c VFS: Add VFS help... |
2779 2780 2781 2782 |
/** * create_mnt_ns - creates a private namespace and adds a root filesystem * @mnt: pointer to the new root filesystem mountpoint */ |
1a4eeaf2a vfs: move mnt_lis... |
2783 |
static struct mnt_namespace *create_mnt_ns(struct vfsmount *m) |
cf8d2c11c VFS: Add VFS help... |
2784 |
{ |
771b13716 vfs: Add a user n... |
2785 |
struct mnt_namespace *new_ns = alloc_mnt_ns(&init_user_ns); |
cf8d2c11c VFS: Add VFS help... |
2786 |
if (!IS_ERR(new_ns)) { |
1a4eeaf2a vfs: move mnt_lis... |
2787 2788 |
struct mount *mnt = real_mount(m); mnt->mnt_ns = new_ns; |
be08d6d26 switch mnt_namesp... |
2789 |
new_ns->root = mnt; |
d29216842 mnt: Add a per mo... |
2790 |
new_ns->mounts++; |
b1983cd89 create_mnt_ns: un... |
2791 |
list_add(&mnt->mnt_list, &new_ns->list); |
c13344958 switch create_mnt... |
2792 |
} else { |
1a4eeaf2a vfs: move mnt_lis... |
2793 |
mntput(m); |
cf8d2c11c VFS: Add VFS help... |
2794 2795 2796 |
} return new_ns; } |
cf8d2c11c VFS: Add VFS help... |
2797 |
|
ea441d110 new helper: mount... |
2798 2799 2800 |
struct dentry *mount_subtree(struct vfsmount *mnt, const char *name) { struct mnt_namespace *ns; |
d31da0f0b mount_subtree() p... |
2801 |
struct super_block *s; |
ea441d110 new helper: mount... |
2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 |
struct path path; int err; ns = create_mnt_ns(mnt); if (IS_ERR(ns)) return ERR_CAST(ns); err = vfs_path_lookup(mnt->mnt_root, mnt, 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... |
2818 2819 |
s = path.mnt->mnt_sb; atomic_inc(&s->s_active); |
ea441d110 new helper: mount... |
2820 2821 |
mntput(path.mnt); /* lock the sucker */ |
d31da0f0b mount_subtree() p... |
2822 |
down_write(&s->s_umount); |
ea441d110 new helper: mount... |
2823 2824 2825 2826 |
/* ... and return the root of (sub)tree on it */ return path.dentry; } EXPORT_SYMBOL(mount_subtree); |
312db1aa1 fs: add ksys_moun... |
2827 2828 |
int ksys_mount(char __user *dev_name, char __user *dir_name, char __user *type, unsigned long flags, void __user *data) |
1da177e4c Linux-2.6.12-rc2 |
2829 |
{ |
eca6f534e fs: fix overflow ... |
2830 2831 |
int ret; char *kernel_type; |
eca6f534e fs: fix overflow ... |
2832 |
char *kernel_dev; |
b40ef8696 saner calling con... |
2833 |
void *options; |
1da177e4c Linux-2.6.12-rc2 |
2834 |
|
b8850d1fa fs: namespace: su... |
2835 2836 2837 |
kernel_type = copy_mount_string(type); ret = PTR_ERR(kernel_type); if (IS_ERR(kernel_type)) |
eca6f534e fs: fix overflow ... |
2838 |
goto out_type; |
1da177e4c Linux-2.6.12-rc2 |
2839 |
|
b8850d1fa fs: namespace: su... |
2840 2841 2842 |
kernel_dev = copy_mount_string(dev_name); ret = PTR_ERR(kernel_dev); if (IS_ERR(kernel_dev)) |
eca6f534e fs: fix overflow ... |
2843 |
goto out_dev; |
1da177e4c Linux-2.6.12-rc2 |
2844 |
|
b40ef8696 saner calling con... |
2845 2846 2847 |
options = copy_mount_options(data); ret = PTR_ERR(options); if (IS_ERR(options)) |
eca6f534e fs: fix overflow ... |
2848 |
goto out_data; |
1da177e4c Linux-2.6.12-rc2 |
2849 |
|
b40ef8696 saner calling con... |
2850 |
ret = do_mount(kernel_dev, dir_name, kernel_type, flags, options); |
1da177e4c Linux-2.6.12-rc2 |
2851 |
|
b40ef8696 saner calling con... |
2852 |
kfree(options); |
eca6f534e fs: fix overflow ... |
2853 2854 2855 |
out_data: kfree(kernel_dev); out_dev: |
eca6f534e fs: fix overflow ... |
2856 2857 2858 |
kfree(kernel_type); out_type: return ret; |
1da177e4c Linux-2.6.12-rc2 |
2859 |
} |
312db1aa1 fs: add ksys_moun... |
2860 2861 2862 2863 2864 |
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 |
2865 |
/* |
afac7cba7 vfs: more mnt_par... |
2866 2867 |
* Return true if path is reachable from root * |
48a066e72 RCU'd vfsmounts |
2868 |
* namespace_sem or mount_lock is held |
afac7cba7 vfs: more mnt_par... |
2869 |
*/ |
643822b41 vfs: spread struc... |
2870 |
bool is_path_reachable(struct mount *mnt, struct dentry *dentry, |
afac7cba7 vfs: more mnt_par... |
2871 2872 |
const struct path *root) { |
643822b41 vfs: spread struc... |
2873 |
while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) { |
a73324da7 vfs: move mnt_mou... |
2874 |
dentry = mnt->mnt_mountpoint; |
0714a5338 vfs: now it can b... |
2875 |
mnt = mnt->mnt_parent; |
afac7cba7 vfs: more mnt_par... |
2876 |
} |
643822b41 vfs: spread struc... |
2877 |
return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry); |
afac7cba7 vfs: more mnt_par... |
2878 |
} |
640eb7e7b fs: Constify path... |
2879 |
bool path_is_under(const struct path *path1, const struct path *path2) |
afac7cba7 vfs: more mnt_par... |
2880 |
{ |
25ab4c9b1 fs/namespace.c: p... |
2881 |
bool res; |
48a066e72 RCU'd vfsmounts |
2882 |
read_seqlock_excl(&mount_lock); |
643822b41 vfs: spread struc... |
2883 |
res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2); |
48a066e72 RCU'd vfsmounts |
2884 |
read_sequnlock_excl(&mount_lock); |
afac7cba7 vfs: more mnt_par... |
2885 2886 2887 2888 2889 |
return res; } EXPORT_SYMBOL(path_is_under); /* |
1da177e4c Linux-2.6.12-rc2 |
2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 |
* 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... |
2902 2903 2904 2905 |
* 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 |
2906 2907 2908 2909 2910 2911 2912 2913 |
* 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... |
2914 2915 |
SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, const char __user *, put_old) |
1da177e4c Linux-2.6.12-rc2 |
2916 |
{ |
2d8f30380 [PATCH] sanitize ... |
2917 |
struct path new, old, parent_path, root_parent, root; |
84d17192d get rid of full-h... |
2918 2919 |
struct mount *new_mnt, *root_mnt, *old_mnt; struct mountpoint *old_mp, *root_mp; |
1da177e4c Linux-2.6.12-rc2 |
2920 |
int error; |
9b40bc90a get rid of unprot... |
2921 |
if (!may_mount()) |
1da177e4c Linux-2.6.12-rc2 |
2922 |
return -EPERM; |
2d8f30380 [PATCH] sanitize ... |
2923 |
error = user_path_dir(new_root, &new); |
1da177e4c Linux-2.6.12-rc2 |
2924 2925 |
if (error) goto out0; |
1da177e4c Linux-2.6.12-rc2 |
2926 |
|
2d8f30380 [PATCH] sanitize ... |
2927 |
error = user_path_dir(put_old, &old); |
1da177e4c Linux-2.6.12-rc2 |
2928 2929 |
if (error) goto out1; |
2d8f30380 [PATCH] sanitize ... |
2930 |
error = security_sb_pivotroot(&old, &new); |
b12cea919 change the lockin... |
2931 2932 |
if (error) goto out2; |
1da177e4c Linux-2.6.12-rc2 |
2933 |
|
f7ad3c6be vfs: add helpers ... |
2934 |
get_fs_root(current->fs, &root); |
84d17192d get rid of full-h... |
2935 2936 2937 |
old_mp = lock_mount(&old); error = PTR_ERR(old_mp); if (IS_ERR(old_mp)) |
b12cea919 change the lockin... |
2938 |
goto out3; |
1da177e4c Linux-2.6.12-rc2 |
2939 |
error = -EINVAL; |
419148da6 vfs: spread struc... |
2940 2941 |
new_mnt = real_mount(new.mnt); root_mnt = real_mount(root.mnt); |
84d17192d get rid of full-h... |
2942 2943 |
old_mnt = real_mount(old.mnt); if (IS_MNT_SHARED(old_mnt) || |
fc7be130c vfs: switch pnode... |
2944 2945 |
IS_MNT_SHARED(new_mnt->mnt_parent) || IS_MNT_SHARED(root_mnt->mnt_parent)) |
b12cea919 change the lockin... |
2946 |
goto out4; |
143c8c91c vfs: mnt_ns moved... |
2947 |
if (!check_mnt(root_mnt) || !check_mnt(new_mnt)) |
b12cea919 change the lockin... |
2948 |
goto out4; |
5ff9d8a65 vfs: Lock in plac... |
2949 2950 |
if (new_mnt->mnt.mnt_flags & MNT_LOCKED) goto out4; |
1da177e4c Linux-2.6.12-rc2 |
2951 |
error = -ENOENT; |
f3da392e9 dcache: extrace a... |
2952 |
if (d_unlinked(new.dentry)) |
b12cea919 change the lockin... |
2953 |
goto out4; |
1da177e4c Linux-2.6.12-rc2 |
2954 |
error = -EBUSY; |
84d17192d get rid of full-h... |
2955 |
if (new_mnt == root_mnt || old_mnt == root_mnt) |
b12cea919 change the lockin... |
2956 |
goto out4; /* loop, on the same file system */ |
1da177e4c Linux-2.6.12-rc2 |
2957 |
error = -EINVAL; |
8c3ee42e8 [PATCH] get rid o... |
2958 |
if (root.mnt->mnt_root != root.dentry) |
b12cea919 change the lockin... |
2959 |
goto out4; /* not a mountpoint */ |
676da58df vfs: spread struc... |
2960 |
if (!mnt_has_parent(root_mnt)) |
b12cea919 change the lockin... |
2961 |
goto out4; /* not attached */ |
84d17192d get rid of full-h... |
2962 |
root_mp = root_mnt->mnt_mp; |
2d8f30380 [PATCH] sanitize ... |
2963 |
if (new.mnt->mnt_root != new.dentry) |
b12cea919 change the lockin... |
2964 |
goto out4; /* not a mountpoint */ |
676da58df vfs: spread struc... |
2965 |
if (!mnt_has_parent(new_mnt)) |
b12cea919 change the lockin... |
2966 |
goto out4; /* not attached */ |
4ac913785 Embed a struct pa... |
2967 |
/* make sure we can reach put_old from new_root */ |
84d17192d get rid of full-h... |
2968 |
if (!is_path_reachable(old_mnt, old.dentry, &new)) |
b12cea919 change the lockin... |
2969 |
goto out4; |
0d0826019 mnt: Prevent pivo... |
2970 2971 2972 |
/* make certain new is below the root */ if (!is_path_reachable(new_mnt, new.dentry, &root)) goto out4; |
84d17192d get rid of full-h... |
2973 |
root_mp->m_count++; /* pin it so it won't go away */ |
719ea2fbb new helpers: lock... |
2974 |
lock_mount_hash(); |
419148da6 vfs: spread struc... |
2975 2976 |
detach_mnt(new_mnt, &parent_path); detach_mnt(root_mnt, &root_parent); |
5ff9d8a65 vfs: Lock in plac... |
2977 2978 2979 2980 |
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... |
2981 |
/* mount old root on put_old */ |
84d17192d get rid of full-h... |
2982 |
attach_mnt(root_mnt, old_mnt, old_mp); |
4ac913785 Embed a struct pa... |
2983 |
/* mount new_root on / */ |
84d17192d get rid of full-h... |
2984 |
attach_mnt(new_mnt, real_mount(root_parent.mnt), root_mp); |
6b3286ed1 [PATCH] rename st... |
2985 |
touch_mnt_namespace(current->nsproxy->mnt_ns); |
4fed655c4 mnt: Clear mnt_ex... |
2986 2987 |
/* A moved mount should not expire automatically */ list_del_init(&new_mnt->mnt_expire); |
3895dbf89 mnt: Protect the ... |
2988 |
put_mountpoint(root_mp); |
719ea2fbb new helpers: lock... |
2989 |
unlock_mount_hash(); |
2d8f30380 [PATCH] sanitize ... |
2990 |
chroot_fs_refs(&root, &new); |
1da177e4c Linux-2.6.12-rc2 |
2991 |
error = 0; |
b12cea919 change the lockin... |
2992 |
out4: |
84d17192d get rid of full-h... |
2993 |
unlock_mount(old_mp); |
b12cea919 change the lockin... |
2994 2995 2996 2997 2998 |
if (!error) { path_put(&root_parent); path_put(&parent_path); } out3: |
8c3ee42e8 [PATCH] get rid o... |
2999 |
path_put(&root); |
b12cea919 change the lockin... |
3000 |
out2: |
2d8f30380 [PATCH] sanitize ... |
3001 |
path_put(&old); |
1da177e4c Linux-2.6.12-rc2 |
3002 |
out1: |
2d8f30380 [PATCH] sanitize ... |
3003 |
path_put(&new); |
1da177e4c Linux-2.6.12-rc2 |
3004 |
out0: |
1da177e4c Linux-2.6.12-rc2 |
3005 |
return error; |
1da177e4c Linux-2.6.12-rc2 |
3006 3007 3008 3009 3010 |
} static void __init init_mount_tree(void) { struct vfsmount *mnt; |
6b3286ed1 [PATCH] rename st... |
3011 |
struct mnt_namespace *ns; |
ac748a09f Make set_fs_{root... |
3012 |
struct path root; |
0c55cfc41 vfs: Allow unpriv... |
3013 |
struct file_system_type *type; |
1da177e4c Linux-2.6.12-rc2 |
3014 |
|
0c55cfc41 vfs: Allow unpriv... |
3015 3016 3017 3018 3019 |
type = get_fs_type("rootfs"); if (!type) panic("Can't find rootfs type"); mnt = vfs_kern_mount(type, 0, "rootfs", NULL); put_filesystem(type); |
1da177e4c Linux-2.6.12-rc2 |
3020 3021 |
if (IS_ERR(mnt)) panic("Can't create rootfs"); |
b3e19d924 fs: scale mntget/... |
3022 |
|
3b22edc57 VFS: Switch init_... |
3023 3024 |
ns = create_mnt_ns(mnt); if (IS_ERR(ns)) |
1da177e4c Linux-2.6.12-rc2 |
3025 |
panic("Can't allocate initial namespace"); |
6b3286ed1 [PATCH] rename st... |
3026 3027 3028 |
init_task.nsproxy->mnt_ns = ns; get_mnt_ns(ns); |
be08d6d26 switch mnt_namesp... |
3029 3030 |
root.mnt = mnt; root.dentry = mnt->mnt_root; |
da362b09e umount: Do not al... |
3031 |
mnt->mnt_flags |= MNT_LOCKED; |
ac748a09f Make set_fs_{root... |
3032 3033 3034 |
set_fs_pwd(current->fs, &root); set_fs_root(current->fs, &root); |
1da177e4c Linux-2.6.12-rc2 |
3035 |
} |
74bf17cff fs: remove the un... |
3036 |
void __init mnt_init(void) |
1da177e4c Linux-2.6.12-rc2 |
3037 |
{ |
15a67dd8c [PATCH] fs/namesp... |
3038 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
3039 |
|
7d6fec45a vfs: start hiding... |
3040 |
mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount), |
20c2df83d mm: Remove slab d... |
3041 |
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
3042 |
|
0818bf27c resizable namespa... |
3043 |
mount_hashtable = alloc_large_system_hash("Mount-cache", |
38129a13e switch mnt_hash t... |
3044 |
sizeof(struct hlist_head), |
0818bf27c resizable namespa... |
3045 |
mhash_entries, 19, |
3d375d785 mm: update caller... |
3046 |
HASH_ZERO, |
0818bf27c resizable namespa... |
3047 3048 3049 3050 |
&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... |
3051 |
HASH_ZERO, |
0818bf27c resizable namespa... |
3052 |
&mp_hash_shift, &mp_hash_mask, 0, 0); |
1da177e4c Linux-2.6.12-rc2 |
3053 |
|
84d17192d get rid of full-h... |
3054 |
if (!mount_hashtable || !mountpoint_hashtable) |
1da177e4c Linux-2.6.12-rc2 |
3055 3056 |
panic("Failed to allocate mount hash table "); |
4b93dc9b1 sysfs, kernfs: pr... |
3057 |
kernfs_init(); |
15a67dd8c [PATCH] fs/namesp... |
3058 3059 3060 3061 |
err = sysfs_init(); if (err) printk(KERN_WARNING "%s: sysfs_init error: %d ", |
8e24eea72 fs: replace remai... |
3062 |
__func__, err); |
00d266662 kobject: convert ... |
3063 3064 |
fs_kobj = kobject_create_and_add("fs", NULL); if (!fs_kobj) |
8e24eea72 fs: replace remai... |
3065 3066 |
printk(KERN_WARNING "%s: kobj create error ", __func__); |
1da177e4c Linux-2.6.12-rc2 |
3067 3068 3069 |
init_rootfs(); init_mount_tree(); } |
616511d03 VFS: Uninline the... |
3070 |
void put_mnt_ns(struct mnt_namespace *ns) |
1da177e4c Linux-2.6.12-rc2 |
3071 |
{ |
d498b25a4 get rid of useles... |
3072 |
if (!atomic_dec_and_test(&ns->count)) |
616511d03 VFS: Uninline the... |
3073 |
return; |
7b00ed6fe put_mnt_ns(): use... |
3074 |
drop_collected_mounts(&ns->root->mnt); |
771b13716 vfs: Add a user n... |
3075 |
free_mnt_ns(ns); |
1da177e4c Linux-2.6.12-rc2 |
3076 |
} |
9d412a43c vfs: split off vf... |
3077 3078 3079 |
struct vfsmount *kern_mount_data(struct file_system_type *type, void *data) { |
423e0ab08 VFS : mount lock ... |
3080 |
struct vfsmount *mnt; |
e462ec50c VFS: Differentiat... |
3081 |
mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, data); |
423e0ab08 VFS : mount lock ... |
3082 3083 3084 3085 3086 |
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_... |
3087 |
real_mount(mnt)->mnt_ns = MNT_NS_INTERNAL; |
423e0ab08 VFS : mount lock ... |
3088 3089 |
} return mnt; |
9d412a43c vfs: split off vf... |
3090 3091 |
} EXPORT_SYMBOL_GPL(kern_mount_data); |
423e0ab08 VFS : mount lock ... |
3092 3093 3094 3095 3096 |
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_... |
3097 |
real_mount(mnt)->mnt_ns = NULL; |
48a066e72 RCU'd vfsmounts |
3098 |
synchronize_rcu(); /* yecchhh... */ |
423e0ab08 VFS : mount lock ... |
3099 3100 3101 3102 |
mntput(mnt); } } EXPORT_SYMBOL(kern_unmount); |
02125a826 fix apparmor dere... |
3103 3104 3105 |
bool our_mnt(struct vfsmount *mnt) { |
143c8c91c vfs: mnt_ns moved... |
3106 |
return check_mnt(real_mount(mnt)); |
02125a826 fix apparmor dere... |
3107 |
} |
8823c079b vfs: Add setns su... |
3108 |
|
3151527ee userns: Don't al... |
3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 |
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; } |
8654df4e2 mnt: Refactor fs_... |
3132 3133 |
static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new, int *new_mnt_flags) |
87a8ebd63 userns: Restrict ... |
3134 |
{ |
8c6cf9cc8 mnt: Modify fs_fu... |
3135 |
int new_flags = *new_mnt_flags; |
87a8ebd63 userns: Restrict ... |
3136 |
struct mount *mnt; |
e51db7353 userns: Better re... |
3137 |
bool visible = false; |
87a8ebd63 userns: Restrict ... |
3138 |
|
44bb4385c fs_is_visible onl... |
3139 |
down_read(&namespace_sem); |
87a8ebd63 userns: Restrict ... |
3140 |
list_for_each_entry(mnt, &ns->list, mnt_list) { |
e51db7353 userns: Better re... |
3141 |
struct mount *child; |
77b1a97d2 mnt: fs_fully_vis... |
3142 |
int mnt_flags; |
8654df4e2 mnt: Refactor fs_... |
3143 |
if (mnt->mnt.mnt_sb->s_type != new->mnt_sb->s_type) |
e51db7353 userns: Better re... |
3144 |
continue; |
7e96c1b0e mnt: Fix fs_fully... |
3145 3146 3147 3148 3149 |
/* 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... |
3150 |
/* A local view of the mount flags */ |
77b1a97d2 mnt: fs_fully_vis... |
3151 |
mnt_flags = mnt->mnt.mnt_flags; |
77b1a97d2 mnt: fs_fully_vis... |
3152 |
|
695e9df01 mnt: Account for ... |
3153 |
/* Don't miss readonly hidden in the superblock flags */ |
bc98a42c1 VFS: Convert sb->... |
3154 |
if (sb_rdonly(mnt->mnt.mnt_sb)) |
695e9df01 mnt: Account for ... |
3155 |
mnt_flags |= MNT_LOCK_READONLY; |
8c6cf9cc8 mnt: Modify fs_fu... |
3156 3157 3158 |
/* Verify the mount flags are equal to or more permissive * than the proposed new mount. */ |
77b1a97d2 mnt: fs_fully_vis... |
3159 |
if ((mnt_flags & MNT_LOCK_READONLY) && |
8c6cf9cc8 mnt: Modify fs_fu... |
3160 3161 |
!(new_flags & MNT_READONLY)) continue; |
77b1a97d2 mnt: fs_fully_vis... |
3162 3163 |
if ((mnt_flags & MNT_LOCK_ATIME) && ((mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK))) |
8c6cf9cc8 mnt: Modify fs_fu... |
3164 |
continue; |
ceeb0e5d3 vfs: Ignore unloc... |
3165 3166 3167 |
/* This mount is not fully visible if there are any * locked child mounts that cover anything except for * empty directories. |
e51db7353 userns: Better re... |
3168 3169 3170 |
*/ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { struct inode *inode = child->mnt_mountpoint->d_inode; |
ceeb0e5d3 vfs: Ignore unloc... |
3171 |
/* Only worry about locked mounts */ |
d71ed6c93 mnt: fs_fully_vis... |
3172 |
if (!(child->mnt.mnt_flags & MNT_LOCKED)) |
ceeb0e5d3 vfs: Ignore unloc... |
3173 |
continue; |
7236c85e1 mnt: Update fs_fu... |
3174 3175 |
/* Is the directory permanetly empty? */ if (!is_empty_dir_inode(inode)) |
e51db7353 userns: Better re... |
3176 |
goto next; |
87a8ebd63 userns: Restrict ... |
3177 |
} |
8c6cf9cc8 mnt: Modify fs_fu... |
3178 |
/* Preserve the locked attributes */ |
77b1a97d2 mnt: fs_fully_vis... |
3179 |
*new_mnt_flags |= mnt_flags & (MNT_LOCK_READONLY | \ |
77b1a97d2 mnt: fs_fully_vis... |
3180 |
MNT_LOCK_ATIME); |
e51db7353 userns: Better re... |
3181 3182 3183 |
visible = true; goto found; next: ; |
87a8ebd63 userns: Restrict ... |
3184 |
} |
e51db7353 userns: Better re... |
3185 |
found: |
44bb4385c fs_is_visible onl... |
3186 |
up_read(&namespace_sem); |
e51db7353 userns: Better re... |
3187 |
return visible; |
87a8ebd63 userns: Restrict ... |
3188 |
} |
8654df4e2 mnt: Refactor fs_... |
3189 3190 |
static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags) { |
a1935c173 mnt: Simplify mou... |
3191 |
const unsigned long required_iflags = SB_I_NOEXEC | SB_I_NODEV; |
8654df4e2 mnt: Refactor fs_... |
3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 |
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? */ s_iflags = mnt->mnt_sb->s_iflags; if (!(s_iflags & SB_I_USERNS_VISIBLE)) return false; |
a1935c173 mnt: Simplify mou... |
3202 3203 3204 3205 3206 3207 |
if ((s_iflags & required_iflags) != required_iflags) { WARN_ONCE(1, "Expected s_iflags to contain 0x%lx ", required_iflags); return true; } |
8654df4e2 mnt: Refactor fs_... |
3208 3209 |
return !mnt_already_visible(ns, mnt, new_mnt_flags); } |
380cf5ba6 fs: Treat foreign... |
3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 |
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... |
3222 |
static struct ns_common *mntns_get(struct task_struct *task) |
8823c079b vfs: Add setns su... |
3223 |
{ |
58be28256 make mntns ->get(... |
3224 |
struct ns_common *ns = NULL; |
8823c079b vfs: Add setns su... |
3225 |
struct nsproxy *nsproxy; |
728dba3a3 namespaces: Use t... |
3226 3227 |
task_lock(task); nsproxy = task->nsproxy; |
8823c079b vfs: Add setns su... |
3228 |
if (nsproxy) { |
58be28256 make mntns ->get(... |
3229 3230 |
ns = &nsproxy->mnt_ns->ns; get_mnt_ns(to_mnt_ns(ns)); |
8823c079b vfs: Add setns su... |
3231 |
} |
728dba3a3 namespaces: Use t... |
3232 |
task_unlock(task); |
8823c079b vfs: Add setns su... |
3233 3234 3235 |
return ns; } |
64964528b make proc_ns_oper... |
3236 |
static void mntns_put(struct ns_common *ns) |
8823c079b vfs: Add setns su... |
3237 |
{ |
58be28256 make mntns ->get(... |
3238 |
put_mnt_ns(to_mnt_ns(ns)); |
8823c079b vfs: Add setns su... |
3239 |
} |
64964528b make proc_ns_oper... |
3240 |
static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns) |
8823c079b vfs: Add setns su... |
3241 3242 |
{ struct fs_struct *fs = current->fs; |
4f757f3cb make sure that mn... |
3243 |
struct mnt_namespace *mnt_ns = to_mnt_ns(ns), *old_mnt_ns; |
8823c079b vfs: Add setns su... |
3244 |
struct path root; |
4f757f3cb make sure that mn... |
3245 |
int err; |
8823c079b vfs: Add setns su... |
3246 |
|
0c55cfc41 vfs: Allow unpriv... |
3247 |
if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) || |
c7b96acf1 userns: Kill nso... |
3248 3249 |
!ns_capable(current_user_ns(), CAP_SYS_CHROOT) || !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) |
ae11e0f18 userns: fix retur... |
3250 |
return -EPERM; |
8823c079b vfs: Add setns su... |
3251 3252 3253 3254 3255 |
if (fs->users != 1) return -EINVAL; get_mnt_ns(mnt_ns); |
4f757f3cb make sure that mn... |
3256 |
old_mnt_ns = nsproxy->mnt_ns; |
8823c079b vfs: Add setns su... |
3257 3258 3259 |
nsproxy->mnt_ns = mnt_ns; /* Find the root */ |
4f757f3cb make sure that mn... |
3260 3261 3262 3263 3264 3265 3266 3267 |
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... |
3268 |
|
4068367c9 fs: don't forget ... |
3269 |
put_mnt_ns(old_mnt_ns); |
8823c079b vfs: Add setns su... |
3270 3271 3272 3273 3274 3275 3276 |
/* 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... |
3277 3278 3279 3280 |
static struct user_namespace *mntns_owner(struct ns_common *ns) { return to_mnt_ns(ns)->user_ns; } |
8823c079b vfs: Add setns su... |
3281 3282 3283 3284 3285 3286 |
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... |
3287 |
.owner = mntns_owner, |
8823c079b vfs: Add setns su... |
3288 |
}; |