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fs/namespace.c
85.5 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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static DEFINE_SPINLOCK(mnt_id_lock); |
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static int mnt_id_start = 0; static int mnt_group_start = 1; |
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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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{ int res; retry: ida_pre_get(&mnt_id_ida, GFP_KERNEL); |
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spin_lock(&mnt_id_lock); |
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res = ida_get_new_above(&mnt_id_ida, mnt_id_start, &mnt->mnt_id); |
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if (!res) |
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mnt_id_start = mnt->mnt_id + 1; |
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spin_unlock(&mnt_id_lock); |
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if (res == -EAGAIN) goto retry; return res; } |
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static void mnt_free_id(struct mount *mnt) |
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{ |
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int id = mnt->mnt_id; |
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spin_lock(&mnt_id_lock); |
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ida_remove(&mnt_id_ida, id); if (mnt_id_start > id) mnt_id_start = id; |
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spin_unlock(&mnt_id_lock); |
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} |
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/* * Allocate a new peer group ID * * mnt_group_ida is protected by namespace_sem */ |
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static int mnt_alloc_group_id(struct mount *mnt) |
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{ |
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int res; |
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if (!ida_pre_get(&mnt_group_ida, GFP_KERNEL)) return -ENOMEM; |
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res = ida_get_new_above(&mnt_group_ida, mnt_group_start, |
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&mnt->mnt_group_id); |
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if (!res) |
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mnt_group_start = mnt->mnt_group_id + 1; |
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return res; |
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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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int id = mnt->mnt_group_id; |
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ida_remove(&mnt_group_ida, id); if (mnt_group_start > id) mnt_group_start = 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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324 |
{ |
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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 (ACCESS_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); /** |
eb04c2828 fs: Add freezing ... |
399 |
* __mnt_want_write_file - get write access to a file's mount |
96029c4e0 fs: introduce mnt... |
400 401 |
* @file: the file who's mount on which to take a write * |
eb04c2828 fs: Add freezing ... |
402 |
* This is like __mnt_want_write, but it takes a file and can |
96029c4e0 fs: introduce mnt... |
403 404 |
* do some optimisations if the file is open for write already */ |
eb04c2828 fs: Add freezing ... |
405 |
int __mnt_want_write_file(struct file *file) |
96029c4e0 fs: introduce mnt... |
406 |
{ |
83f936c75 mark struct file ... |
407 |
if (!(file->f_mode & FMODE_WRITER)) |
eb04c2828 fs: Add freezing ... |
408 |
return __mnt_want_write(file->f_path.mnt); |
96029c4e0 fs: introduce mnt... |
409 410 411 |
else return mnt_clone_write(file->f_path.mnt); } |
eb04c2828 fs: Add freezing ... |
412 413 |
/** |
7c6893e3c ovl: don't allow ... |
414 |
* mnt_want_write_file_path - get write access to a file's mount |
eb04c2828 fs: Add freezing ... |
415 416 417 418 |
* @file: the file who's mount on which to take a write * * This is like mnt_want_write, but it takes a file and can * do some optimisations if the file is open for write already |
7c6893e3c ovl: don't allow ... |
419 420 421 422 423 |
* * Called by the vfs for cases when we have an open file at hand, but will do an * inode operation on it (important distinction for files opened on overlayfs, * since the file operations will come from the real underlying file, while * inode operations come from the overlay). |
eb04c2828 fs: Add freezing ... |
424 |
*/ |
7c6893e3c ovl: don't allow ... |
425 |
int mnt_want_write_file_path(struct file *file) |
eb04c2828 fs: Add freezing ... |
426 427 428 429 430 431 432 433 434 |
{ int ret; sb_start_write(file->f_path.mnt->mnt_sb); ret = __mnt_want_write_file(file); if (ret) sb_end_write(file->f_path.mnt->mnt_sb); return ret; } |
7c6893e3c ovl: don't allow ... |
435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 |
static inline int may_write_real(struct file *file) { struct dentry *dentry = file->f_path.dentry; struct dentry *upperdentry; /* Writable file? */ if (file->f_mode & FMODE_WRITER) return 0; /* Not overlayfs? */ if (likely(!(dentry->d_flags & DCACHE_OP_REAL))) return 0; /* File refers to upper, writable layer? */ upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER); |
954c736f8 ovl: fix may_writ... |
451 452 453 |
if (upperdentry && (file_inode(file) == d_inode(upperdentry) || file_inode(file) == d_inode(dentry))) |
7c6893e3c ovl: don't allow ... |
454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 |
return 0; /* Lower layer: can't write to real file, sorry... */ return -EPERM; } /** * 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 * * Mostly called by filesystems from their ioctl operation before performing * modification. On overlayfs this needs to check if the file is on a read-only * lower layer and deny access in that case. */ int mnt_want_write_file(struct file *file) { int ret; ret = may_write_real(file); if (!ret) { sb_start_write(file_inode(file)->i_sb); ret = __mnt_want_write_file(file); if (ret) sb_end_write(file_inode(file)->i_sb); } return ret; } |
96029c4e0 fs: introduce mnt... |
484 485 486 |
EXPORT_SYMBOL_GPL(mnt_want_write_file); /** |
eb04c2828 fs: Add freezing ... |
487 |
* __mnt_drop_write - give up write access to a mount |
8366025eb [PATCH] r/o bind ... |
488 489 490 491 |
* @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 ... |
492 |
* __mnt_want_write() call above. |
8366025eb [PATCH] r/o bind ... |
493 |
*/ |
eb04c2828 fs: Add freezing ... |
494 |
void __mnt_drop_write(struct vfsmount *mnt) |
8366025eb [PATCH] r/o bind ... |
495 |
{ |
d3ef3d735 fs: mnt_want_writ... |
496 |
preempt_disable(); |
83adc7532 vfs: spread struc... |
497 |
mnt_dec_writers(real_mount(mnt)); |
d3ef3d735 fs: mnt_want_writ... |
498 |
preempt_enable(); |
8366025eb [PATCH] r/o bind ... |
499 |
} |
eb04c2828 fs: Add freezing ... |
500 501 502 503 504 505 506 507 508 509 510 511 512 513 |
/** * 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 ... |
514 |
EXPORT_SYMBOL_GPL(mnt_drop_write); |
eb04c2828 fs: Add freezing ... |
515 516 517 518 |
void __mnt_drop_write_file(struct file *file) { __mnt_drop_write(file->f_path.mnt); } |
7c6893e3c ovl: don't allow ... |
519 |
void mnt_drop_write_file_path(struct file *file) |
2a79f17e4 vfs: mnt_drop_wri... |
520 521 522 |
{ mnt_drop_write(file->f_path.mnt); } |
7c6893e3c ovl: don't allow ... |
523 524 525 526 527 528 |
void mnt_drop_write_file(struct file *file) { __mnt_drop_write(file->f_path.mnt); sb_end_write(file_inode(file)->i_sb); } |
2a79f17e4 vfs: mnt_drop_wri... |
529 |
EXPORT_SYMBOL(mnt_drop_write_file); |
83adc7532 vfs: spread struc... |
530 |
static int mnt_make_readonly(struct mount *mnt) |
8366025eb [PATCH] r/o bind ... |
531 |
{ |
3d733633a [PATCH] r/o bind ... |
532 |
int ret = 0; |
719ea2fbb new helpers: lock... |
533 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
534 |
mnt->mnt.mnt_flags |= MNT_WRITE_HOLD; |
3d733633a [PATCH] r/o bind ... |
535 |
/* |
d3ef3d735 fs: mnt_want_writ... |
536 537 |
* After storing MNT_WRITE_HOLD, we'll read the counters. This store * should be visible before we do. |
3d733633a [PATCH] r/o bind ... |
538 |
*/ |
d3ef3d735 fs: mnt_want_writ... |
539 |
smp_mb(); |
3d733633a [PATCH] r/o bind ... |
540 |
/* |
d3ef3d735 fs: mnt_want_writ... |
541 542 543 544 545 546 547 548 549 550 551 552 553 554 |
* 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 ... |
555 |
*/ |
c6653a838 fs: rename vfsmou... |
556 |
if (mnt_get_writers(mnt) > 0) |
d3ef3d735 fs: mnt_want_writ... |
557 558 |
ret = -EBUSY; else |
83adc7532 vfs: spread struc... |
559 |
mnt->mnt.mnt_flags |= MNT_READONLY; |
d3ef3d735 fs: mnt_want_writ... |
560 561 562 563 564 |
/* * MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers * that become unheld will see MNT_READONLY. */ smp_wmb(); |
83adc7532 vfs: spread struc... |
565 |
mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD; |
719ea2fbb new helpers: lock... |
566 |
unlock_mount_hash(); |
3d733633a [PATCH] r/o bind ... |
567 |
return ret; |
8366025eb [PATCH] r/o bind ... |
568 |
} |
8366025eb [PATCH] r/o bind ... |
569 |
|
83adc7532 vfs: spread struc... |
570 |
static void __mnt_unmake_readonly(struct mount *mnt) |
2e4b7fcd9 [PATCH] r/o bind ... |
571 |
{ |
719ea2fbb new helpers: lock... |
572 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
573 |
mnt->mnt.mnt_flags &= ~MNT_READONLY; |
719ea2fbb new helpers: lock... |
574 |
unlock_mount_hash(); |
2e4b7fcd9 [PATCH] r/o bind ... |
575 |
} |
4ed5e82fe vfs: protect remo... |
576 577 578 579 |
int sb_prepare_remount_readonly(struct super_block *sb) { struct mount *mnt; int err = 0; |
8e8b87964 vfs: prevent remo... |
580 581 582 |
/* Racy optimization. Recheck the counter under MNT_WRITE_HOLD */ if (atomic_long_read(&sb->s_remove_count)) return -EBUSY; |
719ea2fbb new helpers: lock... |
583 |
lock_mount_hash(); |
4ed5e82fe vfs: protect remo... |
584 585 586 587 588 589 590 591 592 593 |
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... |
594 595 |
if (!err && atomic_long_read(&sb->s_remove_count)) err = -EBUSY; |
4ed5e82fe vfs: protect remo... |
596 597 598 599 600 601 602 603 |
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... |
604 |
unlock_mount_hash(); |
4ed5e82fe vfs: protect remo... |
605 606 607 |
return err; } |
b105e270b vfs: spread struc... |
608 |
static void free_vfsmnt(struct mount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
609 |
{ |
fcc139ae2 fs/namespace: con... |
610 |
kfree_const(mnt->mnt_devname); |
d3ef3d735 fs: mnt_want_writ... |
611 |
#ifdef CONFIG_SMP |
68e8a9fea vfs: all counters... |
612 |
free_percpu(mnt->mnt_pcp); |
d3ef3d735 fs: mnt_want_writ... |
613 |
#endif |
b105e270b vfs: spread struc... |
614 |
kmem_cache_free(mnt_cache, mnt); |
1da177e4c Linux-2.6.12-rc2 |
615 |
} |
8ffcb32e0 VFS: Make delayed... |
616 617 618 619 |
static void delayed_free_vfsmnt(struct rcu_head *head) { free_vfsmnt(container_of(head, struct mount, mnt_rcu)); } |
48a066e72 RCU'd vfsmounts |
620 |
/* call under rcu_read_lock */ |
294d71ff2 new helper: __leg... |
621 |
int __legitimize_mnt(struct vfsmount *bastard, unsigned seq) |
48a066e72 RCU'd vfsmounts |
622 623 624 |
{ struct mount *mnt; if (read_seqretry(&mount_lock, seq)) |
294d71ff2 new helper: __leg... |
625 |
return 1; |
48a066e72 RCU'd vfsmounts |
626 |
if (bastard == NULL) |
294d71ff2 new helper: __leg... |
627 |
return 0; |
48a066e72 RCU'd vfsmounts |
628 629 630 |
mnt = real_mount(bastard); mnt_add_count(mnt, 1); if (likely(!read_seqretry(&mount_lock, seq))) |
294d71ff2 new helper: __leg... |
631 |
return 0; |
48a066e72 RCU'd vfsmounts |
632 633 |
if (bastard->mnt_flags & MNT_SYNC_UMOUNT) { mnt_add_count(mnt, -1); |
294d71ff2 new helper: __leg... |
634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 |
return 1; } 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 |
649 |
} |
48a066e72 RCU'd vfsmounts |
650 651 |
return false; } |
1da177e4c Linux-2.6.12-rc2 |
652 |
/* |
474279dc0 split __lookup_mn... |
653 |
* find the first mount at @dentry on vfsmount @mnt. |
48a066e72 RCU'd vfsmounts |
654 |
* call under rcu_read_lock() |
1da177e4c Linux-2.6.12-rc2 |
655 |
*/ |
474279dc0 split __lookup_mn... |
656 |
struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4c Linux-2.6.12-rc2 |
657 |
{ |
38129a13e switch mnt_hash t... |
658 |
struct hlist_head *head = m_hash(mnt, dentry); |
474279dc0 split __lookup_mn... |
659 |
struct mount *p; |
38129a13e switch mnt_hash t... |
660 |
hlist_for_each_entry_rcu(p, head, mnt_hash) |
474279dc0 split __lookup_mn... |
661 662 663 664 665 666 |
if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) return p; return NULL; } /* |
f015f1267 VFS: Comment moun... |
667 668 669 670 671 672 673 674 675 676 677 678 679 680 |
* 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... |
681 |
*/ |
ca71cf71e namespace.c: cons... |
682 |
struct vfsmount *lookup_mnt(const struct path *path) |
a05964f39 [PATCH] shared mo... |
683 |
{ |
c71053659 vfs: spread struc... |
684 |
struct mount *child_mnt; |
48a066e72 RCU'd vfsmounts |
685 686 |
struct vfsmount *m; unsigned seq; |
99b7db7b8 fs: brlock vfsmou... |
687 |
|
48a066e72 RCU'd vfsmounts |
688 689 690 691 692 693 694 695 |
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... |
696 |
} |
7af1364ff vfs: Don't allow ... |
697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 |
/* * __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... |
731 |
static struct mountpoint *lookup_mountpoint(struct dentry *dentry) |
84d17192d get rid of full-h... |
732 |
{ |
0818bf27c resizable namespa... |
733 |
struct hlist_head *chain = mp_hash(dentry); |
84d17192d get rid of full-h... |
734 |
struct mountpoint *mp; |
0818bf27c resizable namespa... |
735 |
hlist_for_each_entry(mp, chain, m_hash) { |
84d17192d get rid of full-h... |
736 737 738 739 740 741 742 743 |
if (mp->m_dentry == dentry) { /* might be worth a WARN_ON() */ if (d_unlinked(dentry)) return ERR_PTR(-ENOENT); mp->m_count++; return mp; } } |
e2dfa9354 vfs: factor out l... |
744 745 |
return NULL; } |
3895dbf89 mnt: Protect the ... |
746 |
static struct mountpoint *get_mountpoint(struct dentry *dentry) |
e2dfa9354 vfs: factor out l... |
747 |
{ |
3895dbf89 mnt: Protect the ... |
748 |
struct mountpoint *mp, *new = NULL; |
e2dfa9354 vfs: factor out l... |
749 |
int ret; |
84d17192d get rid of full-h... |
750 |
|
3895dbf89 mnt: Protect the ... |
751 752 753 754 755 756 757 758 759 760 761 762 |
if (d_mountpoint(dentry)) { 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... |
763 |
return ERR_PTR(-ENOMEM); |
3895dbf89 mnt: Protect the ... |
764 765 |
/* Exactly one processes may set d_mounted */ |
eed810076 vfs: check unlink... |
766 |
ret = d_set_mounted(dentry); |
eed810076 vfs: check unlink... |
767 |
|
3895dbf89 mnt: Protect the ... |
768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 |
/* 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... |
789 790 791 792 793 794 795 |
return mp; } static void put_mountpoint(struct mountpoint *mp) { if (!--mp->m_count) { struct dentry *dentry = mp->m_dentry; |
0a5eb7c81 vfs: Keep a list ... |
796 |
BUG_ON(!hlist_empty(&mp->m_list)); |
84d17192d get rid of full-h... |
797 798 799 |
spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_MOUNTED; spin_unlock(&dentry->d_lock); |
0818bf27c resizable namespa... |
800 |
hlist_del(&mp->m_hash); |
84d17192d get rid of full-h... |
801 802 803 |
kfree(mp); } } |
143c8c91c vfs: mnt_ns moved... |
804 |
static inline int check_mnt(struct mount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
805 |
{ |
6b3286ed1 [PATCH] rename st... |
806 |
return mnt->mnt_ns == current->nsproxy->mnt_ns; |
1da177e4c Linux-2.6.12-rc2 |
807 |
} |
99b7db7b8 fs: brlock vfsmou... |
808 809 810 |
/* * vfsmount lock must be held for write */ |
6b3286ed1 [PATCH] rename st... |
811 |
static void touch_mnt_namespace(struct mnt_namespace *ns) |
5addc5dd8 [PATCH] make /pro... |
812 813 814 815 816 817 |
{ if (ns) { ns->event = ++event; wake_up_interruptible(&ns->poll); } } |
99b7db7b8 fs: brlock vfsmou... |
818 819 820 |
/* * vfsmount lock must be held for write */ |
6b3286ed1 [PATCH] rename st... |
821 |
static void __touch_mnt_namespace(struct mnt_namespace *ns) |
5addc5dd8 [PATCH] make /pro... |
822 823 824 825 826 827 |
{ if (ns && ns->event != event) { ns->event = event; wake_up_interruptible(&ns->poll); } } |
99b7db7b8 fs: brlock vfsmou... |
828 829 830 |
/* * vfsmount lock must be held for write */ |
7bdb11de8 mnt: Factor out u... |
831 |
static void unhash_mnt(struct mount *mnt) |
419148da6 vfs: spread struc... |
832 |
{ |
0714a5338 vfs: now it can b... |
833 |
mnt->mnt_parent = mnt; |
a73324da7 vfs: move mnt_mou... |
834 |
mnt->mnt_mountpoint = mnt->mnt.mnt_root; |
6b41d536f vfs: take mnt_chi... |
835 |
list_del_init(&mnt->mnt_child); |
38129a13e switch mnt_hash t... |
836 |
hlist_del_init_rcu(&mnt->mnt_hash); |
0a5eb7c81 vfs: Keep a list ... |
837 |
hlist_del_init(&mnt->mnt_mp_list); |
84d17192d get rid of full-h... |
838 839 |
put_mountpoint(mnt->mnt_mp); mnt->mnt_mp = NULL; |
1da177e4c Linux-2.6.12-rc2 |
840 |
} |
99b7db7b8 fs: brlock vfsmou... |
841 842 843 |
/* * vfsmount lock must be held for write */ |
7bdb11de8 mnt: Factor out u... |
844 845 846 847 848 849 850 851 852 853 |
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... |
854 855 856 857 858 859 860 861 862 863 |
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... |
864 865 |
void mnt_set_mountpoint(struct mount *mnt, struct mountpoint *mp, |
44d964d60 vfs: spread struc... |
866 |
struct mount *child_mnt) |
b90fa9ae8 [PATCH] shared mo... |
867 |
{ |
84d17192d get rid of full-h... |
868 |
mp->m_count++; |
3a2393d71 vfs: opencode mnt... |
869 |
mnt_add_count(mnt, 1); /* essentially, that's mntget */ |
84d17192d get rid of full-h... |
870 |
child_mnt->mnt_mountpoint = dget(mp->m_dentry); |
3a2393d71 vfs: opencode mnt... |
871 |
child_mnt->mnt_parent = mnt; |
84d17192d get rid of full-h... |
872 |
child_mnt->mnt_mp = mp; |
0a5eb7c81 vfs: Keep a list ... |
873 |
hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list); |
b90fa9ae8 [PATCH] shared mo... |
874 |
} |
1064f874a mnt: Tuck mounts ... |
875 876 877 878 879 880 |
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... |
881 882 883 |
/* * vfsmount lock must be held for write */ |
84d17192d get rid of full-h... |
884 885 886 |
static void attach_mnt(struct mount *mnt, struct mount *parent, struct mountpoint *mp) |
1da177e4c Linux-2.6.12-rc2 |
887 |
{ |
84d17192d get rid of full-h... |
888 |
mnt_set_mountpoint(parent, mp, mnt); |
1064f874a mnt: Tuck mounts ... |
889 |
__attach_mnt(mnt, parent); |
b90fa9ae8 [PATCH] shared mo... |
890 |
} |
1064f874a mnt: Tuck mounts ... |
891 |
void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *mnt) |
12a5b5294 fix copy_tree() r... |
892 |
{ |
1064f874a mnt: Tuck mounts ... |
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 |
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... |
921 |
} |
b90fa9ae8 [PATCH] shared mo... |
922 |
/* |
99b7db7b8 fs: brlock vfsmou... |
923 |
* vfsmount lock must be held for write |
b90fa9ae8 [PATCH] shared mo... |
924 |
*/ |
1064f874a mnt: Tuck mounts ... |
925 |
static void commit_tree(struct mount *mnt) |
b90fa9ae8 [PATCH] shared mo... |
926 |
{ |
0714a5338 vfs: now it can b... |
927 |
struct mount *parent = mnt->mnt_parent; |
83adc7532 vfs: spread struc... |
928 |
struct mount *m; |
b90fa9ae8 [PATCH] shared mo... |
929 |
LIST_HEAD(head); |
143c8c91c vfs: mnt_ns moved... |
930 |
struct mnt_namespace *n = parent->mnt_ns; |
b90fa9ae8 [PATCH] shared mo... |
931 |
|
0714a5338 vfs: now it can b... |
932 |
BUG_ON(parent == mnt); |
b90fa9ae8 [PATCH] shared mo... |
933 |
|
1a4eeaf2a vfs: move mnt_lis... |
934 |
list_add_tail(&head, &mnt->mnt_list); |
f7a99c5b7 get rid of ->mnt_... |
935 |
list_for_each_entry(m, &head, mnt_list) |
143c8c91c vfs: mnt_ns moved... |
936 |
m->mnt_ns = n; |
f03c65993 sanitize vfsmount... |
937 |
|
b90fa9ae8 [PATCH] shared mo... |
938 |
list_splice(&head, n->list.prev); |
d29216842 mnt: Add a per mo... |
939 940 |
n->mounts += n->pending_mounts; n->pending_mounts = 0; |
1064f874a mnt: Tuck mounts ... |
941 |
__attach_mnt(mnt, parent); |
6b3286ed1 [PATCH] rename st... |
942 |
touch_mnt_namespace(n); |
1da177e4c Linux-2.6.12-rc2 |
943 |
} |
909b0a88e vfs: spread struc... |
944 |
static struct mount *next_mnt(struct mount *p, struct mount *root) |
1da177e4c Linux-2.6.12-rc2 |
945 |
{ |
6b41d536f vfs: take mnt_chi... |
946 947 |
struct list_head *next = p->mnt_mounts.next; if (next == &p->mnt_mounts) { |
1da177e4c Linux-2.6.12-rc2 |
948 |
while (1) { |
909b0a88e vfs: spread struc... |
949 |
if (p == root) |
1da177e4c Linux-2.6.12-rc2 |
950 |
return NULL; |
6b41d536f vfs: take mnt_chi... |
951 952 |
next = p->mnt_child.next; if (next != &p->mnt_parent->mnt_mounts) |
1da177e4c Linux-2.6.12-rc2 |
953 |
break; |
0714a5338 vfs: now it can b... |
954 |
p = p->mnt_parent; |
1da177e4c Linux-2.6.12-rc2 |
955 956 |
} } |
6b41d536f vfs: take mnt_chi... |
957 |
return list_entry(next, struct mount, mnt_child); |
1da177e4c Linux-2.6.12-rc2 |
958 |
} |
315fc83e5 vfs: spread struc... |
959 |
static struct mount *skip_mnt_tree(struct mount *p) |
9676f0c63 [PATCH] unbindabl... |
960 |
{ |
6b41d536f vfs: take mnt_chi... |
961 962 963 964 |
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... |
965 966 967 |
} return p; } |
9d412a43c vfs: split off vf... |
968 969 970 |
struct vfsmount * vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data) { |
b105e270b vfs: spread struc... |
971 |
struct mount *mnt; |
9d412a43c vfs: split off vf... |
972 973 974 975 976 977 978 979 |
struct dentry *root; if (!type) return ERR_PTR(-ENODEV); mnt = alloc_vfsmnt(name); if (!mnt) return ERR_PTR(-ENOMEM); |
e462ec50c VFS: Differentiat... |
980 |
if (flags & SB_KERNMOUNT) |
b105e270b vfs: spread struc... |
981 |
mnt->mnt.mnt_flags = MNT_INTERNAL; |
9d412a43c vfs: split off vf... |
982 983 984 |
root = mount_fs(type, flags, name, data); if (IS_ERR(root)) { |
8ffcb32e0 VFS: Make delayed... |
985 |
mnt_free_id(mnt); |
9d412a43c vfs: split off vf... |
986 987 988 |
free_vfsmnt(mnt); return ERR_CAST(root); } |
b105e270b vfs: spread struc... |
989 990 |
mnt->mnt.mnt_root = root; mnt->mnt.mnt_sb = root->d_sb; |
a73324da7 vfs: move mnt_mou... |
991 |
mnt->mnt_mountpoint = mnt->mnt.mnt_root; |
0714a5338 vfs: now it can b... |
992 |
mnt->mnt_parent = mnt; |
719ea2fbb new helpers: lock... |
993 |
lock_mount_hash(); |
39f7c4db1 vfs: keep list of... |
994 |
list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts); |
719ea2fbb new helpers: lock... |
995 |
unlock_mount_hash(); |
b105e270b vfs: spread struc... |
996 |
return &mnt->mnt; |
9d412a43c vfs: split off vf... |
997 998 |
} EXPORT_SYMBOL_GPL(vfs_kern_mount); |
93faccbbf fs: Better permis... |
999 1000 1001 1002 1003 1004 1005 1006 1007 1008 |
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... |
1009 |
return vfs_kern_mount(type, SB_SUBMOUNT, name, data); |
93faccbbf fs: Better permis... |
1010 1011 |
} EXPORT_SYMBOL_GPL(vfs_submount); |
87129cc0e vfs: spread struc... |
1012 |
static struct mount *clone_mnt(struct mount *old, struct dentry *root, |
36341f645 [PATCH] mount exp... |
1013 |
int flag) |
1da177e4c Linux-2.6.12-rc2 |
1014 |
{ |
87129cc0e vfs: spread struc... |
1015 |
struct super_block *sb = old->mnt.mnt_sb; |
be34d1a3b VFS: Make clone_m... |
1016 1017 |
struct mount *mnt; int err; |
1da177e4c Linux-2.6.12-rc2 |
1018 |
|
be34d1a3b VFS: Make clone_m... |
1019 1020 1021 |
mnt = alloc_vfsmnt(old->mnt_devname); if (!mnt) return ERR_PTR(-ENOMEM); |
719f5d7f0 [patch 4/7] vfs: ... |
1022 |
|
7a472ef4b vfs: Only support... |
1023 |
if (flag & (CL_SLAVE | CL_PRIVATE | CL_SHARED_TO_SLAVE)) |
be34d1a3b VFS: Make clone_m... |
1024 1025 1026 |
mnt->mnt_group_id = 0; /* not a peer of original */ else mnt->mnt_group_id = old->mnt_group_id; |
b90fa9ae8 [PATCH] shared mo... |
1027 |
|
be34d1a3b VFS: Make clone_m... |
1028 1029 1030 1031 |
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 |
1032 |
} |
be34d1a3b VFS: Make clone_m... |
1033 |
|
f2ebb3a92 smarter propagate... |
1034 |
mnt->mnt.mnt_flags = old->mnt.mnt_flags & ~(MNT_WRITE_HOLD|MNT_MARKED); |
132c94e31 vfs: Carefully pr... |
1035 |
/* Don't allow unprivileged users to change mount flags */ |
9566d6742 mnt: Correct perm... |
1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 |
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... |
1051 |
|
5ff9d8a65 vfs: Lock in plac... |
1052 |
/* Don't allow unprivileged users to reveal what is under a mount */ |
381cacb12 mnt: Carefully se... |
1053 1054 |
if ((flag & CL_UNPRIVILEGED) && (!(flag & CL_EXPIRE) || list_empty(&old->mnt_expire))) |
5ff9d8a65 vfs: Lock in plac... |
1055 |
mnt->mnt.mnt_flags |= MNT_LOCKED; |
be34d1a3b VFS: Make clone_m... |
1056 1057 1058 1059 1060 |
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... |
1061 |
lock_mount_hash(); |
be34d1a3b VFS: Make clone_m... |
1062 |
list_add_tail(&mnt->mnt_instance, &sb->s_mounts); |
719ea2fbb new helpers: lock... |
1063 |
unlock_mount_hash(); |
be34d1a3b VFS: Make clone_m... |
1064 |
|
7a472ef4b vfs: Only support... |
1065 1066 |
if ((flag & CL_SLAVE) || ((flag & CL_SHARED_TO_SLAVE) && IS_MNT_SHARED(old))) { |
be34d1a3b VFS: Make clone_m... |
1067 1068 1069 1070 1071 1072 1073 1074 1075 |
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... |
1076 1077 |
} else { CLEAR_MNT_SHARED(mnt); |
be34d1a3b VFS: Make clone_m... |
1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 |
} 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... |
1088 |
return mnt; |
719f5d7f0 [patch 4/7] vfs: ... |
1089 1090 |
out_free: |
8ffcb32e0 VFS: Make delayed... |
1091 |
mnt_free_id(mnt); |
719f5d7f0 [patch 4/7] vfs: ... |
1092 |
free_vfsmnt(mnt); |
be34d1a3b VFS: Make clone_m... |
1093 |
return ERR_PTR(err); |
1da177e4c Linux-2.6.12-rc2 |
1094 |
} |
9ea459e11 delayed mntput |
1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 |
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'... |
1126 |
struct mount *m, *t; |
9ea459e11 delayed mntput |
1127 |
|
297857357 namespace.c: Don'... |
1128 1129 |
llist_for_each_entry_safe(m, t, node, mnt_llist) cleanup_mnt(m); |
9ea459e11 delayed mntput |
1130 1131 |
} static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput); |
900148dca vfs: spread struc... |
1132 |
static void mntput_no_expire(struct mount *mnt) |
b3e19d924 fs: scale mntget/... |
1133 |
{ |
48a066e72 RCU'd vfsmounts |
1134 1135 1136 1137 |
rcu_read_lock(); mnt_add_count(mnt, -1); if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */ rcu_read_unlock(); |
f03c65993 sanitize vfsmount... |
1138 |
return; |
b3e19d924 fs: scale mntget/... |
1139 |
} |
719ea2fbb new helpers: lock... |
1140 |
lock_mount_hash(); |
b3e19d924 fs: scale mntget/... |
1141 |
if (mnt_get_count(mnt)) { |
48a066e72 RCU'd vfsmounts |
1142 |
rcu_read_unlock(); |
719ea2fbb new helpers: lock... |
1143 |
unlock_mount_hash(); |
99b7db7b8 fs: brlock vfsmou... |
1144 1145 |
return; } |
48a066e72 RCU'd vfsmounts |
1146 1147 1148 1149 1150 1151 1152 |
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: ... |
1153 |
|
39f7c4db1 vfs: keep list of... |
1154 |
list_del(&mnt->mnt_instance); |
ce07d891a mnt: Honor MNT_LO... |
1155 1156 1157 1158 1159 1160 1161 |
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... |
1162 |
unlock_mount_hash(); |
649a795af fold mntfree() in... |
1163 |
|
9ea459e11 delayed mntput |
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 |
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/... |
1176 |
} |
b3e19d924 fs: scale mntget/... |
1177 1178 1179 1180 |
void mntput(struct vfsmount *mnt) { if (mnt) { |
863d684f9 vfs: move the res... |
1181 |
struct mount *m = real_mount(mnt); |
b3e19d924 fs: scale mntget/... |
1182 |
/* avoid cacheline pingpong, hope gcc doesn't get "smart" */ |
863d684f9 vfs: move the res... |
1183 1184 1185 |
if (unlikely(m->mnt_expiry_mark)) m->mnt_expiry_mark = 0; mntput_no_expire(m); |
b3e19d924 fs: scale mntget/... |
1186 1187 1188 1189 1190 1191 1192 |
} } EXPORT_SYMBOL(mntput); struct vfsmount *mntget(struct vfsmount *mnt) { if (mnt) |
83adc7532 vfs: spread struc... |
1193 |
mnt_add_count(real_mount(mnt), 1); |
b3e19d924 fs: scale mntget/... |
1194 1195 1196 |
return mnt; } EXPORT_SYMBOL(mntget); |
c6609c0a1 vfs: add path_is_... |
1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 |
/* 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... |
1225 |
struct vfsmount *mnt_clone_internal(const struct path *path) |
7b7b1ace2 [PATCH] saner han... |
1226 |
{ |
3064c3563 death to mnt_pinned |
1227 1228 1229 1230 1231 1232 |
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... |
1233 |
} |
1da177e4c Linux-2.6.12-rc2 |
1234 |
|
a1a2c409b [patch 5/7] vfs: ... |
1235 |
#ifdef CONFIG_PROC_FS |
0226f4923 vfs: take /proc/*... |
1236 |
/* iterator; we want it to have access to namespace_sem, thus here... */ |
1da177e4c Linux-2.6.12-rc2 |
1237 1238 |
static void *m_start(struct seq_file *m, loff_t *pos) { |
ede1bf0dc fs: use seq_open_... |
1239 |
struct proc_mounts *p = m->private; |
1da177e4c Linux-2.6.12-rc2 |
1240 |
|
390c68436 [PATCH] making na... |
1241 |
down_read(&namespace_sem); |
c7999c362 reduce m_start() ... |
1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 |
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 |
1256 1257 1258 1259 |
} static void *m_next(struct seq_file *m, void *v, loff_t *pos) { |
ede1bf0dc fs: use seq_open_... |
1260 |
struct proc_mounts *p = m->private; |
b0765fb85 Make /proc/self/m... |
1261 |
|
c7999c362 reduce m_start() ... |
1262 1263 1264 |
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 |
1265 1266 1267 1268 |
} static void m_stop(struct seq_file *m, void *v) { |
390c68436 [PATCH] making na... |
1269 |
up_read(&namespace_sem); |
1da177e4c Linux-2.6.12-rc2 |
1270 |
} |
0226f4923 vfs: take /proc/*... |
1271 |
static int m_show(struct seq_file *m, void *v) |
2d4d4864a [patch 6/7] vfs: ... |
1272 |
{ |
ede1bf0dc fs: use seq_open_... |
1273 |
struct proc_mounts *p = m->private; |
1a4eeaf2a vfs: move mnt_lis... |
1274 |
struct mount *r = list_entry(v, struct mount, mnt_list); |
0226f4923 vfs: take /proc/*... |
1275 |
return p->show(m, &r->mnt); |
1da177e4c Linux-2.6.12-rc2 |
1276 |
} |
a1a2c409b [patch 5/7] vfs: ... |
1277 |
const struct seq_operations mounts_op = { |
1da177e4c Linux-2.6.12-rc2 |
1278 1279 1280 |
.start = m_start, .next = m_next, .stop = m_stop, |
0226f4923 vfs: take /proc/*... |
1281 |
.show = m_show, |
b4629fe2f VFS: New /proc fi... |
1282 |
}; |
a1a2c409b [patch 5/7] vfs: ... |
1283 |
#endif /* CONFIG_PROC_FS */ |
b4629fe2f VFS: New /proc fi... |
1284 |
|
1da177e4c Linux-2.6.12-rc2 |
1285 1286 1287 1288 1289 1290 1291 1292 |
/** * 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... |
1293 |
int may_umount_tree(struct vfsmount *m) |
1da177e4c Linux-2.6.12-rc2 |
1294 |
{ |
909b0a88e vfs: spread struc... |
1295 |
struct mount *mnt = real_mount(m); |
36341f645 [PATCH] mount exp... |
1296 1297 |
int actual_refs = 0; int minimum_refs = 0; |
315fc83e5 vfs: spread struc... |
1298 |
struct mount *p; |
909b0a88e vfs: spread struc... |
1299 |
BUG_ON(!m); |
1da177e4c Linux-2.6.12-rc2 |
1300 |
|
b3e19d924 fs: scale mntget/... |
1301 |
/* write lock needed for mnt_get_count */ |
719ea2fbb new helpers: lock... |
1302 |
lock_mount_hash(); |
909b0a88e vfs: spread struc... |
1303 |
for (p = mnt; p; p = next_mnt(p, mnt)) { |
83adc7532 vfs: spread struc... |
1304 |
actual_refs += mnt_get_count(p); |
1da177e4c Linux-2.6.12-rc2 |
1305 |
minimum_refs += 2; |
1da177e4c Linux-2.6.12-rc2 |
1306 |
} |
719ea2fbb new helpers: lock... |
1307 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1308 1309 |
if (actual_refs > minimum_refs) |
e3474a8eb [PATCH] autofs4: ... |
1310 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1311 |
|
e3474a8eb [PATCH] autofs4: ... |
1312 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 |
} 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: ... |
1332 |
int ret = 1; |
8ad08d8a0 may_umount() need... |
1333 |
down_read(&namespace_sem); |
719ea2fbb new helpers: lock... |
1334 |
lock_mount_hash(); |
1ab597386 vfs: spread struc... |
1335 |
if (propagate_mount_busy(real_mount(mnt), 2)) |
e3474a8eb [PATCH] autofs4: ... |
1336 |
ret = 0; |
719ea2fbb new helpers: lock... |
1337 |
unlock_mount_hash(); |
8ad08d8a0 may_umount() need... |
1338 |
up_read(&namespace_sem); |
a05964f39 [PATCH] shared mo... |
1339 |
return ret; |
1da177e4c Linux-2.6.12-rc2 |
1340 1341 1342 |
} EXPORT_SYMBOL(may_umount); |
38129a13e switch mnt_hash t... |
1343 |
static HLIST_HEAD(unmounted); /* protected by namespace_sem */ |
e3197d83d saner umount_tree... |
1344 |
|
97216be09 fold release_moun... |
1345 |
static void namespace_unlock(void) |
70fbcdf4d [PATCH] umount_tr... |
1346 |
{ |
a3b3c5627 mnt: Use hlist_mo... |
1347 |
struct hlist_head head; |
97216be09 fold release_moun... |
1348 |
|
a3b3c5627 mnt: Use hlist_mo... |
1349 |
hlist_move_list(&unmounted, &head); |
97216be09 fold release_moun... |
1350 |
|
97216be09 fold release_moun... |
1351 |
up_write(&namespace_sem); |
a3b3c5627 mnt: Use hlist_mo... |
1352 1353 |
if (likely(hlist_empty(&head))) return; |
48a066e72 RCU'd vfsmounts |
1354 |
synchronize_rcu(); |
87b95ce09 switch the IO-tri... |
1355 |
group_pin_kill(&head); |
70fbcdf4d [PATCH] umount_tr... |
1356 |
} |
97216be09 fold release_moun... |
1357 |
static inline void namespace_lock(void) |
e3197d83d saner umount_tree... |
1358 |
{ |
97216be09 fold release_moun... |
1359 |
down_write(&namespace_sem); |
e3197d83d saner umount_tree... |
1360 |
} |
e819f1521 mnt: Improve the ... |
1361 1362 1363 |
enum umount_tree_flags { UMOUNT_SYNC = 1, UMOUNT_PROPAGATE = 2, |
e0c9c0afd mnt: Update detac... |
1364 |
UMOUNT_CONNECTED = 4, |
e819f1521 mnt: Improve the ... |
1365 |
}; |
f2d0a123b mnt: Clarify and ... |
1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 |
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... |
1395 |
/* |
48a066e72 RCU'd vfsmounts |
1396 |
* mount_lock must be held |
99b7db7b8 fs: brlock vfsmou... |
1397 1398 |
* namespace_sem must be held for write */ |
e819f1521 mnt: Improve the ... |
1399 |
static void umount_tree(struct mount *mnt, enum umount_tree_flags how) |
1da177e4c Linux-2.6.12-rc2 |
1400 |
{ |
c003b26ff mnt: In umount_tr... |
1401 |
LIST_HEAD(tmp_list); |
315fc83e5 vfs: spread struc... |
1402 |
struct mount *p; |
1da177e4c Linux-2.6.12-rc2 |
1403 |
|
5d88457eb mnt: On an unmoun... |
1404 1405 |
if (how & UMOUNT_PROPAGATE) propagate_mount_unlock(mnt); |
c003b26ff mnt: In umount_tr... |
1406 |
/* Gather the mounts to umount */ |
590ce4bcb mnt: Add MNT_UMOU... |
1407 1408 |
for (p = mnt; p; p = next_mnt(p, mnt)) { p->mnt.mnt_flags |= MNT_UMOUNT; |
c003b26ff mnt: In umount_tr... |
1409 |
list_move(&p->mnt_list, &tmp_list); |
590ce4bcb mnt: Add MNT_UMOU... |
1410 |
} |
1da177e4c Linux-2.6.12-rc2 |
1411 |
|
411a938b5 mnt: Delay remova... |
1412 |
/* Hide the mounts from mnt_mounts */ |
c003b26ff mnt: In umount_tr... |
1413 |
list_for_each_entry(p, &tmp_list, mnt_list) { |
88b368f27 get rid of propag... |
1414 |
list_del_init(&p->mnt_child); |
c003b26ff mnt: In umount_tr... |
1415 |
} |
88b368f27 get rid of propag... |
1416 |
|
c003b26ff mnt: In umount_tr... |
1417 |
/* Add propogated mounts to the tmp_list */ |
e819f1521 mnt: Improve the ... |
1418 |
if (how & UMOUNT_PROPAGATE) |
7b8a53fd8 fix old umount_tr... |
1419 |
propagate_umount(&tmp_list); |
a05964f39 [PATCH] shared mo... |
1420 |
|
c003b26ff mnt: In umount_tr... |
1421 |
while (!list_empty(&tmp_list)) { |
d29216842 mnt: Add a per mo... |
1422 |
struct mnt_namespace *ns; |
ce07d891a mnt: Honor MNT_LO... |
1423 |
bool disconnect; |
c003b26ff mnt: In umount_tr... |
1424 |
p = list_first_entry(&tmp_list, struct mount, mnt_list); |
6776db3d3 vfs: take mnt_sha... |
1425 |
list_del_init(&p->mnt_expire); |
1a4eeaf2a vfs: move mnt_lis... |
1426 |
list_del_init(&p->mnt_list); |
d29216842 mnt: Add a per mo... |
1427 1428 1429 1430 1431 |
ns = p->mnt_ns; if (ns) { ns->mounts--; __touch_mnt_namespace(ns); } |
143c8c91c vfs: mnt_ns moved... |
1432 |
p->mnt_ns = NULL; |
e819f1521 mnt: Improve the ... |
1433 |
if (how & UMOUNT_SYNC) |
48a066e72 RCU'd vfsmounts |
1434 |
p->mnt.mnt_flags |= MNT_SYNC_UMOUNT; |
87b95ce09 switch the IO-tri... |
1435 |
|
f2d0a123b mnt: Clarify and ... |
1436 |
disconnect = disconnect_mount(p, how); |
ce07d891a mnt: Honor MNT_LO... |
1437 1438 1439 |
pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt, disconnect ? &unmounted : NULL); |
676da58df vfs: spread struc... |
1440 |
if (mnt_has_parent(p)) { |
81b6b0619 fix EBUSY on umou... |
1441 |
mnt_add_count(p->mnt_parent, -1); |
ce07d891a mnt: Honor MNT_LO... |
1442 1443 1444 1445 1446 1447 |
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... |
1448 |
} |
0f0afb1dc vfs: spread struc... |
1449 |
change_mnt_propagation(p, MS_PRIVATE); |
1da177e4c Linux-2.6.12-rc2 |
1450 1451 |
} } |
b54b9be78 get rid of the se... |
1452 |
static void shrink_submounts(struct mount *mnt); |
c35038bec [PATCH] do shrink... |
1453 |
|
1ab597386 vfs: spread struc... |
1454 |
static int do_umount(struct mount *mnt, int flags) |
1da177e4c Linux-2.6.12-rc2 |
1455 |
{ |
1ab597386 vfs: spread struc... |
1456 |
struct super_block *sb = mnt->mnt.mnt_sb; |
1da177e4c Linux-2.6.12-rc2 |
1457 |
int retval; |
1ab597386 vfs: spread struc... |
1458 |
retval = security_sb_umount(&mnt->mnt, flags); |
1da177e4c Linux-2.6.12-rc2 |
1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 |
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... |
1469 |
if (&mnt->mnt == current->fs->root.mnt || |
1da177e4c Linux-2.6.12-rc2 |
1470 1471 |
flags & (MNT_FORCE | MNT_DETACH)) return -EINVAL; |
b3e19d924 fs: scale mntget/... |
1472 1473 1474 1475 |
/* * probably don't strictly need the lock here if we examined * all race cases, but it's a slowpath. */ |
719ea2fbb new helpers: lock... |
1476 |
lock_mount_hash(); |
83adc7532 vfs: spread struc... |
1477 |
if (mnt_get_count(mnt) != 2) { |
719ea2fbb new helpers: lock... |
1478 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1479 |
return -EBUSY; |
b3e19d924 fs: scale mntget/... |
1480 |
} |
719ea2fbb new helpers: lock... |
1481 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1482 |
|
863d684f9 vfs: move the res... |
1483 |
if (!xchg(&mnt->mnt_expiry_mark, 1)) |
1da177e4c Linux-2.6.12-rc2 |
1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 |
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... |
1496 |
if (flags & MNT_FORCE && sb->s_op->umount_begin) { |
42faad996 [PATCH] restore s... |
1497 |
sb->s_op->umount_begin(sb); |
42faad996 [PATCH] restore s... |
1498 |
} |
1da177e4c Linux-2.6.12-rc2 |
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 |
/* * 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... |
1509 |
if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) { |
1da177e4c Linux-2.6.12-rc2 |
1510 1511 1512 1513 |
/* * Special case for "unmounting" root ... * we just try to remount it readonly. */ |
a1480dcc3 fs: Add a missing... |
1514 1515 |
if (!capable(CAP_SYS_ADMIN)) return -EPERM; |
1da177e4c Linux-2.6.12-rc2 |
1516 |
down_write(&sb->s_umount); |
bc98a42c1 VFS: Convert sb->... |
1517 |
if (!sb_rdonly(sb)) |
e462ec50c VFS: Differentiat... |
1518 |
retval = do_remount_sb(sb, SB_RDONLY, NULL, 0); |
1da177e4c Linux-2.6.12-rc2 |
1519 1520 1521 |
up_write(&sb->s_umount); return retval; } |
97216be09 fold release_moun... |
1522 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
1523 |
lock_mount_hash(); |
5addc5dd8 [PATCH] make /pro... |
1524 |
event++; |
1da177e4c Linux-2.6.12-rc2 |
1525 |
|
48a066e72 RCU'd vfsmounts |
1526 |
if (flags & MNT_DETACH) { |
1a4eeaf2a vfs: move mnt_lis... |
1527 |
if (!list_empty(&mnt->mnt_list)) |
e819f1521 mnt: Improve the ... |
1528 |
umount_tree(mnt, UMOUNT_PROPAGATE); |
1da177e4c Linux-2.6.12-rc2 |
1529 |
retval = 0; |
48a066e72 RCU'd vfsmounts |
1530 1531 1532 1533 1534 |
} else { shrink_submounts(mnt); retval = -EBUSY; if (!propagate_mount_busy(mnt, 2)) { if (!list_empty(&mnt->mnt_list)) |
e819f1521 mnt: Improve the ... |
1535 |
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
48a066e72 RCU'd vfsmounts |
1536 1537 |
retval = 0; } |
1da177e4c Linux-2.6.12-rc2 |
1538 |
} |
719ea2fbb new helpers: lock... |
1539 |
unlock_mount_hash(); |
e3197d83d saner umount_tree... |
1540 |
namespace_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1541 1542 |
return retval; } |
80b5dce8c vfs: Add a functi... |
1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 |
/* * __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 ... |
1559 |
lock_mount_hash(); |
80b5dce8c vfs: Add a functi... |
1560 |
mp = lookup_mountpoint(dentry); |
f53e57975 mnt: Fix the erro... |
1561 |
if (IS_ERR_OR_NULL(mp)) |
80b5dce8c vfs: Add a functi... |
1562 |
goto out_unlock; |
e06b933e6 namespace: update... |
1563 |
event++; |
80b5dce8c vfs: Add a functi... |
1564 1565 |
while (!hlist_empty(&mp->m_list)) { mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list); |
ce07d891a mnt: Honor MNT_LO... |
1566 |
if (mnt->mnt.mnt_flags & MNT_UMOUNT) { |
fe78fcc85 mnt: In detach_mo... |
1567 1568 |
hlist_add_head(&mnt->mnt_umount.s_list, &unmounted); umount_mnt(mnt); |
ce07d891a mnt: Honor MNT_LO... |
1569 |
} |
e0c9c0afd mnt: Update detac... |
1570 |
else umount_tree(mnt, UMOUNT_CONNECTED); |
80b5dce8c vfs: Add a functi... |
1571 |
} |
80b5dce8c vfs: Add a functi... |
1572 1573 |
put_mountpoint(mp); out_unlock: |
3895dbf89 mnt: Protect the ... |
1574 |
unlock_mount_hash(); |
80b5dce8c vfs: Add a functi... |
1575 1576 |
namespace_unlock(); } |
dd111b31e VFS: Clean up whi... |
1577 |
/* |
9b40bc90a get rid of unprot... |
1578 1579 1580 1581 1582 1583 |
* 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... |
1584 1585 1586 1587 1588 |
static inline bool may_mandlock(void) { #ifndef CONFIG_MANDATORY_FILE_LOCKING return false; #endif |
95ace7541 locks: Don't allo... |
1589 |
return capable(CAP_SYS_ADMIN); |
9e8925b67 locks: Allow disa... |
1590 |
} |
1da177e4c Linux-2.6.12-rc2 |
1591 1592 1593 1594 1595 1596 1597 |
/* * 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 */ |
bdc480e3b [CVE-2009-0029] S... |
1598 |
SYSCALL_DEFINE2(umount, char __user *, name, int, flags) |
1da177e4c Linux-2.6.12-rc2 |
1599 |
{ |
2d8f30380 [PATCH] sanitize ... |
1600 |
struct path path; |
900148dca vfs: spread struc... |
1601 |
struct mount *mnt; |
1da177e4c Linux-2.6.12-rc2 |
1602 |
int retval; |
db1f05bb8 vfs: add NOFOLLOW... |
1603 |
int lookup_flags = 0; |
1da177e4c Linux-2.6.12-rc2 |
1604 |
|
db1f05bb8 vfs: add NOFOLLOW... |
1605 1606 |
if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW)) return -EINVAL; |
9b40bc90a get rid of unprot... |
1607 1608 |
if (!may_mount()) return -EPERM; |
db1f05bb8 vfs: add NOFOLLOW... |
1609 1610 |
if (!(flags & UMOUNT_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; |
197df04c7 rename user_path_... |
1611 |
retval = user_path_mountpoint_at(AT_FDCWD, name, lookup_flags, &path); |
1da177e4c Linux-2.6.12-rc2 |
1612 1613 |
if (retval) goto out; |
900148dca vfs: spread struc... |
1614 |
mnt = real_mount(path.mnt); |
1da177e4c Linux-2.6.12-rc2 |
1615 |
retval = -EINVAL; |
2d8f30380 [PATCH] sanitize ... |
1616 |
if (path.dentry != path.mnt->mnt_root) |
1da177e4c Linux-2.6.12-rc2 |
1617 |
goto dput_and_out; |
143c8c91c vfs: mnt_ns moved... |
1618 |
if (!check_mnt(mnt)) |
1da177e4c Linux-2.6.12-rc2 |
1619 |
goto dput_and_out; |
5ff9d8a65 vfs: Lock in plac... |
1620 1621 |
if (mnt->mnt.mnt_flags & MNT_LOCKED) goto dput_and_out; |
b2f5d4dc3 umount: Disallow ... |
1622 1623 1624 |
retval = -EPERM; if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN)) goto dput_and_out; |
1da177e4c Linux-2.6.12-rc2 |
1625 |
|
900148dca vfs: spread struc... |
1626 |
retval = do_umount(mnt, flags); |
1da177e4c Linux-2.6.12-rc2 |
1627 |
dput_and_out: |
429731b15 Remove path_relea... |
1628 |
/* we mustn't call path_put() as that would clear mnt_expiry_mark */ |
2d8f30380 [PATCH] sanitize ... |
1629 |
dput(path.dentry); |
900148dca vfs: spread struc... |
1630 |
mntput_no_expire(mnt); |
1da177e4c Linux-2.6.12-rc2 |
1631 1632 1633 1634 1635 1636 1637 |
out: return retval; } #ifdef __ARCH_WANT_SYS_OLDUMOUNT /* |
b58fed8b1 [PATCH] lindent f... |
1638 |
* The 2.0 compatible umount. No flags. |
1da177e4c Linux-2.6.12-rc2 |
1639 |
*/ |
bdc480e3b [CVE-2009-0029] S... |
1640 |
SYSCALL_DEFINE1(oldumount, char __user *, name) |
1da177e4c Linux-2.6.12-rc2 |
1641 |
{ |
b58fed8b1 [PATCH] lindent f... |
1642 |
return sys_umount(name, 0); |
1da177e4c Linux-2.6.12-rc2 |
1643 1644 1645 |
} #endif |
4ce5d2b1a vfs: Don't copy m... |
1646 |
static bool is_mnt_ns_file(struct dentry *dentry) |
8823c079b vfs: Add setns su... |
1647 |
{ |
4ce5d2b1a vfs: Don't copy m... |
1648 |
/* Is this a proxy for a mount namespace? */ |
e149ed2b8 take the targets ... |
1649 1650 |
return dentry->d_op == &ns_dentry_operations && dentry->d_fsdata == &mntns_operations; |
4ce5d2b1a vfs: Don't copy m... |
1651 |
} |
58be28256 make mntns ->get(... |
1652 1653 1654 1655 |
struct mnt_namespace *to_mnt_ns(struct ns_common *ns) { return container_of(ns, struct mnt_namespace, ns); } |
4ce5d2b1a vfs: Don't copy m... |
1656 1657 1658 1659 1660 1661 1662 1663 |
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_... |
1664 |
mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode)); |
8823c079b vfs: Add setns su... |
1665 1666 |
return current->nsproxy->mnt_ns->seq >= mnt_ns->seq; } |
87129cc0e vfs: spread struc... |
1667 |
struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, |
36341f645 [PATCH] mount exp... |
1668 |
int flag) |
1da177e4c Linux-2.6.12-rc2 |
1669 |
{ |
84d17192d get rid of full-h... |
1670 |
struct mount *res, *p, *q, *r, *parent; |
1da177e4c Linux-2.6.12-rc2 |
1671 |
|
4ce5d2b1a vfs: Don't copy m... |
1672 1673 1674 1675 |
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... |
1676 |
return ERR_PTR(-EINVAL); |
9676f0c63 [PATCH] unbindabl... |
1677 |
|
36341f645 [PATCH] mount exp... |
1678 |
res = q = clone_mnt(mnt, dentry, flag); |
be34d1a3b VFS: Make clone_m... |
1679 1680 |
if (IS_ERR(q)) return q; |
a73324da7 vfs: move mnt_mou... |
1681 |
q->mnt_mountpoint = mnt->mnt_mountpoint; |
1da177e4c Linux-2.6.12-rc2 |
1682 1683 |
p = mnt; |
6b41d536f vfs: take mnt_chi... |
1684 |
list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) { |
315fc83e5 vfs: spread struc... |
1685 |
struct mount *s; |
7ec02ef15 vfs: remove lives... |
1686 |
if (!is_subdir(r->mnt_mountpoint, dentry)) |
1da177e4c Linux-2.6.12-rc2 |
1687 |
continue; |
909b0a88e vfs: spread struc... |
1688 |
for (s = r; s; s = next_mnt(s, r)) { |
4ce5d2b1a vfs: Don't copy m... |
1689 1690 1691 1692 1693 1694 1695 |
if (!(flag & CL_COPY_UNBINDABLE) && IS_MNT_UNBINDABLE(s)) { s = skip_mnt_tree(s); continue; } if (!(flag & CL_COPY_MNT_NS_FILE) && is_mnt_ns_file(s->mnt.mnt_root)) { |
9676f0c63 [PATCH] unbindabl... |
1696 1697 1698 |
s = skip_mnt_tree(s); continue; } |
0714a5338 vfs: now it can b... |
1699 1700 1701 |
while (p != s->mnt_parent) { p = p->mnt_parent; q = q->mnt_parent; |
1da177e4c Linux-2.6.12-rc2 |
1702 |
} |
87129cc0e vfs: spread struc... |
1703 |
p = s; |
84d17192d get rid of full-h... |
1704 |
parent = q; |
87129cc0e vfs: spread struc... |
1705 |
q = clone_mnt(p, p->mnt.mnt_root, flag); |
be34d1a3b VFS: Make clone_m... |
1706 1707 |
if (IS_ERR(q)) goto out; |
719ea2fbb new helpers: lock... |
1708 |
lock_mount_hash(); |
1a4eeaf2a vfs: move mnt_lis... |
1709 |
list_add_tail(&q->mnt_list, &res->mnt_list); |
1064f874a mnt: Tuck mounts ... |
1710 |
attach_mnt(q, parent, p->mnt_mp); |
719ea2fbb new helpers: lock... |
1711 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1712 1713 1714 |
} } return res; |
be34d1a3b VFS: Make clone_m... |
1715 |
out: |
1da177e4c Linux-2.6.12-rc2 |
1716 |
if (res) { |
719ea2fbb new helpers: lock... |
1717 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
1718 |
umount_tree(res, UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
1719 |
unlock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
1720 |
} |
be34d1a3b VFS: Make clone_m... |
1721 |
return q; |
1da177e4c Linux-2.6.12-rc2 |
1722 |
} |
be34d1a3b VFS: Make clone_m... |
1723 |
/* Caller should check returned pointer for errors */ |
ca71cf71e namespace.c: cons... |
1724 |
struct vfsmount *collect_mounts(const struct path *path) |
8aec08094 [PATCH] new helpe... |
1725 |
{ |
cb338d06e vfs: spread struc... |
1726 |
struct mount *tree; |
97216be09 fold release_moun... |
1727 |
namespace_lock(); |
cd4a40174 mnt: Fail collect... |
1728 1729 1730 1731 1732 |
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... |
1733 |
namespace_unlock(); |
be34d1a3b VFS: Make clone_m... |
1734 |
if (IS_ERR(tree)) |
52e220d35 VFS: collect_moun... |
1735 |
return ERR_CAST(tree); |
be34d1a3b VFS: Make clone_m... |
1736 |
return &tree->mnt; |
8aec08094 [PATCH] new helpe... |
1737 1738 1739 1740 |
} void drop_collected_mounts(struct vfsmount *mnt) { |
97216be09 fold release_moun... |
1741 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
1742 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
1743 |
umount_tree(real_mount(mnt), UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
1744 |
unlock_mount_hash(); |
3ab6abee5 more conversions ... |
1745 |
namespace_unlock(); |
8aec08094 [PATCH] new helpe... |
1746 |
} |
c771d683a vfs: introduce cl... |
1747 1748 1749 1750 1751 1752 1753 1754 1755 |
/** * 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... |
1756 |
struct vfsmount *clone_private_mount(const struct path *path) |
c771d683a vfs: introduce cl... |
1757 1758 1759 1760 1761 1762 |
{ 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... |
1763 |
new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE); |
c771d683a vfs: introduce cl... |
1764 1765 1766 1767 1768 1769 |
if (IS_ERR(new_mnt)) return ERR_CAST(new_mnt); return &new_mnt->mnt; } EXPORT_SYMBOL_GPL(clone_private_mount); |
1f707137b new helper: itera... |
1770 1771 1772 |
int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, struct vfsmount *root) { |
1a4eeaf2a vfs: move mnt_lis... |
1773 |
struct mount *mnt; |
1f707137b new helper: itera... |
1774 1775 1776 |
int res = f(root, arg); if (res) return res; |
1a4eeaf2a vfs: move mnt_lis... |
1777 1778 |
list_for_each_entry(mnt, &real_mount(root)->mnt_list, mnt_list) { res = f(&mnt->mnt, arg); |
1f707137b new helper: itera... |
1779 1780 1781 1782 1783 |
if (res) return res; } return 0; } |
4b8b21f4f vfs: spread struc... |
1784 |
static void cleanup_group_ids(struct mount *mnt, struct mount *end) |
719f5d7f0 [patch 4/7] vfs: ... |
1785 |
{ |
315fc83e5 vfs: spread struc... |
1786 |
struct mount *p; |
719f5d7f0 [patch 4/7] vfs: ... |
1787 |
|
909b0a88e vfs: spread struc... |
1788 |
for (p = mnt; p != end; p = next_mnt(p, mnt)) { |
fc7be130c vfs: switch pnode... |
1789 |
if (p->mnt_group_id && !IS_MNT_SHARED(p)) |
4b8b21f4f vfs: spread struc... |
1790 |
mnt_release_group_id(p); |
719f5d7f0 [patch 4/7] vfs: ... |
1791 1792 |
} } |
4b8b21f4f vfs: spread struc... |
1793 |
static int invent_group_ids(struct mount *mnt, bool recurse) |
719f5d7f0 [patch 4/7] vfs: ... |
1794 |
{ |
315fc83e5 vfs: spread struc... |
1795 |
struct mount *p; |
719f5d7f0 [patch 4/7] vfs: ... |
1796 |
|
909b0a88e vfs: spread struc... |
1797 |
for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) { |
fc7be130c vfs: switch pnode... |
1798 |
if (!p->mnt_group_id && !IS_MNT_SHARED(p)) { |
4b8b21f4f vfs: spread struc... |
1799 |
int err = mnt_alloc_group_id(p); |
719f5d7f0 [patch 4/7] vfs: ... |
1800 |
if (err) { |
4b8b21f4f vfs: spread struc... |
1801 |
cleanup_group_ids(mnt, p); |
719f5d7f0 [patch 4/7] vfs: ... |
1802 1803 1804 1805 1806 1807 1808 |
return err; } } } return 0; } |
d29216842 mnt: Add a per mo... |
1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 |
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... |
1830 1831 |
/* * @source_mnt : mount tree to be attached |
214444032 [PATCH] shared mo... |
1832 1833 1834 1835 |
* @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... |
1836 1837 1838 |
* * 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... |
1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 |
* --------------------------------------------------------------------------- * | 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... |
1851 1852 1853 1854 1855 1856 1857 1858 1859 |
* 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 ... |
1860 1861 1862 1863 1864 1865 1866 |
* (+++) 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... |
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 |
* --------------------------------------------------------------------------- * | MOVE MOUNT OPERATION | * |************************************************************************** * | source-->| shared | private | slave | unbindable | * | dest | | | | | * | | | | | | | * | v | | | | | * |************************************************************************** * | shared | shared (+) | shared (+) | shared(+++) | invalid | * | | | | | | * |non-shared| shared (+*) | private | slave (*) | unbindable | * *************************************************************************** |
5afe00221 [PATCH] handling ... |
1879 1880 1881 |
* * (+) 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... |
1882 |
* (+*) the mount is moved to the destination. |
5afe00221 [PATCH] handling ... |
1883 1884 1885 1886 |
* (+++) 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... |
1887 1888 1889 1890 1891 1892 |
* * 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... |
1893 |
static int attach_recursive_mnt(struct mount *source_mnt, |
84d17192d get rid of full-h... |
1894 1895 1896 |
struct mount *dest_mnt, struct mountpoint *dest_mp, struct path *parent_path) |
b90fa9ae8 [PATCH] shared mo... |
1897 |
{ |
38129a13e switch mnt_hash t... |
1898 |
HLIST_HEAD(tree_list); |
d29216842 mnt: Add a per mo... |
1899 |
struct mnt_namespace *ns = dest_mnt->mnt_ns; |
1064f874a mnt: Tuck mounts ... |
1900 |
struct mountpoint *smp; |
315fc83e5 vfs: spread struc... |
1901 |
struct mount *child, *p; |
38129a13e switch mnt_hash t... |
1902 |
struct hlist_node *n; |
719f5d7f0 [patch 4/7] vfs: ... |
1903 |
int err; |
b90fa9ae8 [PATCH] shared mo... |
1904 |
|
1064f874a mnt: Tuck mounts ... |
1905 1906 1907 1908 1909 1910 |
/* 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... |
1911 1912 1913 1914 1915 1916 |
/* 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... |
1917 |
if (IS_MNT_SHARED(dest_mnt)) { |
0fb54e505 vfs: spread struc... |
1918 |
err = invent_group_ids(source_mnt, true); |
719f5d7f0 [patch 4/7] vfs: ... |
1919 1920 |
if (err) goto out; |
0b1b901b5 don't bother with... |
1921 |
err = propagate_mnt(dest_mnt, dest_mp, source_mnt, &tree_list); |
f2ebb3a92 smarter propagate... |
1922 |
lock_mount_hash(); |
0b1b901b5 don't bother with... |
1923 1924 |
if (err) goto out_cleanup_ids; |
909b0a88e vfs: spread struc... |
1925 |
for (p = source_mnt; p; p = next_mnt(p, source_mnt)) |
0f0afb1dc vfs: spread struc... |
1926 |
set_mnt_shared(p); |
0b1b901b5 don't bother with... |
1927 1928 |
} else { lock_mount_hash(); |
b90fa9ae8 [PATCH] shared mo... |
1929 |
} |
1a3906895 [PATCH] reduce st... |
1930 |
if (parent_path) { |
0fb54e505 vfs: spread struc... |
1931 |
detach_mnt(source_mnt, parent_path); |
84d17192d get rid of full-h... |
1932 |
attach_mnt(source_mnt, dest_mnt, dest_mp); |
143c8c91c vfs: mnt_ns moved... |
1933 |
touch_mnt_namespace(source_mnt->mnt_ns); |
214444032 [PATCH] shared mo... |
1934 |
} else { |
84d17192d get rid of full-h... |
1935 |
mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); |
1064f874a mnt: Tuck mounts ... |
1936 |
commit_tree(source_mnt); |
214444032 [PATCH] shared mo... |
1937 |
} |
b90fa9ae8 [PATCH] shared mo... |
1938 |
|
38129a13e switch mnt_hash t... |
1939 |
hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) { |
1d6a32acd keep shadowed vfs... |
1940 |
struct mount *q; |
38129a13e switch mnt_hash t... |
1941 |
hlist_del_init(&child->mnt_hash); |
1064f874a mnt: Tuck mounts ... |
1942 1943 1944 1945 1946 |
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... |
1947 |
} |
1064f874a mnt: Tuck mounts ... |
1948 |
put_mountpoint(smp); |
719ea2fbb new helpers: lock... |
1949 |
unlock_mount_hash(); |
99b7db7b8 fs: brlock vfsmou... |
1950 |
|
b90fa9ae8 [PATCH] shared mo... |
1951 |
return 0; |
719f5d7f0 [patch 4/7] vfs: ... |
1952 1953 |
out_cleanup_ids: |
f2ebb3a92 smarter propagate... |
1954 1955 |
while (!hlist_empty(&tree_list)) { child = hlist_entry(tree_list.first, struct mount, mnt_hash); |
d29216842 mnt: Add a per mo... |
1956 |
child->mnt_parent->mnt_ns->pending_mounts = 0; |
e819f1521 mnt: Improve the ... |
1957 |
umount_tree(child, UMOUNT_SYNC); |
f2ebb3a92 smarter propagate... |
1958 1959 |
} unlock_mount_hash(); |
0b1b901b5 don't bother with... |
1960 |
cleanup_group_ids(source_mnt, NULL); |
719f5d7f0 [patch 4/7] vfs: ... |
1961 |
out: |
d29216842 mnt: Add a per mo... |
1962 |
ns->pending_mounts = 0; |
1064f874a mnt: Tuck mounts ... |
1963 1964 1965 1966 |
read_seqlock_excl(&mount_lock); put_mountpoint(smp); read_sequnlock_excl(&mount_lock); |
719f5d7f0 [patch 4/7] vfs: ... |
1967 |
return err; |
b90fa9ae8 [PATCH] shared mo... |
1968 |
} |
84d17192d get rid of full-h... |
1969 |
static struct mountpoint *lock_mount(struct path *path) |
b12cea919 change the lockin... |
1970 1971 |
{ struct vfsmount *mnt; |
84d17192d get rid of full-h... |
1972 |
struct dentry *dentry = path->dentry; |
b12cea919 change the lockin... |
1973 |
retry: |
5955102c9 wrappers for ->i_... |
1974 |
inode_lock(dentry->d_inode); |
84d17192d get rid of full-h... |
1975 |
if (unlikely(cant_mount(dentry))) { |
5955102c9 wrappers for ->i_... |
1976 |
inode_unlock(dentry->d_inode); |
84d17192d get rid of full-h... |
1977 |
return ERR_PTR(-ENOENT); |
b12cea919 change the lockin... |
1978 |
} |
97216be09 fold release_moun... |
1979 |
namespace_lock(); |
b12cea919 change the lockin... |
1980 |
mnt = lookup_mnt(path); |
84d17192d get rid of full-h... |
1981 |
if (likely(!mnt)) { |
3895dbf89 mnt: Protect the ... |
1982 |
struct mountpoint *mp = get_mountpoint(dentry); |
84d17192d get rid of full-h... |
1983 |
if (IS_ERR(mp)) { |
97216be09 fold release_moun... |
1984 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
1985 |
inode_unlock(dentry->d_inode); |
84d17192d get rid of full-h... |
1986 1987 1988 1989 |
return mp; } return mp; } |
97216be09 fold release_moun... |
1990 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
1991 |
inode_unlock(path->dentry->d_inode); |
b12cea919 change the lockin... |
1992 1993 |
path_put(path); path->mnt = mnt; |
84d17192d get rid of full-h... |
1994 |
dentry = path->dentry = dget(mnt->mnt_root); |
b12cea919 change the lockin... |
1995 1996 |
goto retry; } |
84d17192d get rid of full-h... |
1997 |
static void unlock_mount(struct mountpoint *where) |
b12cea919 change the lockin... |
1998 |
{ |
84d17192d get rid of full-h... |
1999 |
struct dentry *dentry = where->m_dentry; |
3895dbf89 mnt: Protect the ... |
2000 2001 |
read_seqlock_excl(&mount_lock); |
84d17192d get rid of full-h... |
2002 |
put_mountpoint(where); |
3895dbf89 mnt: Protect the ... |
2003 |
read_sequnlock_excl(&mount_lock); |
328e6d901 switch unlock_mou... |
2004 |
namespace_unlock(); |
5955102c9 wrappers for ->i_... |
2005 |
inode_unlock(dentry->d_inode); |
b12cea919 change the lockin... |
2006 |
} |
84d17192d get rid of full-h... |
2007 |
static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp) |
1da177e4c Linux-2.6.12-rc2 |
2008 |
{ |
e462ec50c VFS: Differentiat... |
2009 |
if (mnt->mnt.mnt_sb->s_flags & SB_NOUSER) |
1da177e4c Linux-2.6.12-rc2 |
2010 |
return -EINVAL; |
e36cb0b89 VFS: (Scripted) C... |
2011 2012 |
if (d_is_dir(mp->m_dentry) != d_is_dir(mnt->mnt.mnt_root)) |
1da177e4c Linux-2.6.12-rc2 |
2013 |
return -ENOTDIR; |
84d17192d get rid of full-h... |
2014 |
return attach_recursive_mnt(mnt, p, mp, NULL); |
1da177e4c Linux-2.6.12-rc2 |
2015 2016 2017 |
} /* |
7a2e8a8fa VFS: Sanity check... |
2018 2019 |
* Sanity check the flags to change_mnt_propagation. */ |
e462ec50c VFS: Differentiat... |
2020 |
static int flags_to_propagation_type(int ms_flags) |
7a2e8a8fa VFS: Sanity check... |
2021 |
{ |
e462ec50c VFS: Differentiat... |
2022 |
int type = ms_flags & ~(MS_REC | MS_SILENT); |
7a2e8a8fa VFS: Sanity check... |
2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 |
/* 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... |
2034 2035 |
* recursively change the type of the mountpoint. */ |
e462ec50c VFS: Differentiat... |
2036 |
static int do_change_type(struct path *path, int ms_flags) |
07b20889e [PATCH] beginning... |
2037 |
{ |
315fc83e5 vfs: spread struc... |
2038 |
struct mount *m; |
4b8b21f4f vfs: spread struc... |
2039 |
struct mount *mnt = real_mount(path->mnt); |
e462ec50c VFS: Differentiat... |
2040 |
int recurse = ms_flags & MS_REC; |
7a2e8a8fa VFS: Sanity check... |
2041 |
int type; |
719f5d7f0 [patch 4/7] vfs: ... |
2042 |
int err = 0; |
07b20889e [PATCH] beginning... |
2043 |
|
2d92ab3c6 [PATCH] finally g... |
2044 |
if (path->dentry != path->mnt->mnt_root) |
07b20889e [PATCH] beginning... |
2045 |
return -EINVAL; |
e462ec50c VFS: Differentiat... |
2046 |
type = flags_to_propagation_type(ms_flags); |
7a2e8a8fa VFS: Sanity check... |
2047 2048 |
if (!type) return -EINVAL; |
97216be09 fold release_moun... |
2049 |
namespace_lock(); |
719f5d7f0 [patch 4/7] vfs: ... |
2050 2051 2052 2053 2054 |
if (type == MS_SHARED) { err = invent_group_ids(mnt, recurse); if (err) goto out_unlock; } |
719ea2fbb new helpers: lock... |
2055 |
lock_mount_hash(); |
909b0a88e vfs: spread struc... |
2056 |
for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL)) |
0f0afb1dc vfs: spread struc... |
2057 |
change_mnt_propagation(m, type); |
719ea2fbb new helpers: lock... |
2058 |
unlock_mount_hash(); |
719f5d7f0 [patch 4/7] vfs: ... |
2059 2060 |
out_unlock: |
97216be09 fold release_moun... |
2061 |
namespace_unlock(); |
719f5d7f0 [patch 4/7] vfs: ... |
2062 |
return err; |
07b20889e [PATCH] beginning... |
2063 |
} |
5ff9d8a65 vfs: Lock in plac... |
2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 |
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... |
2076 |
/* |
1da177e4c Linux-2.6.12-rc2 |
2077 2078 |
* do loopback mount. */ |
808d4e3cf consitify do_moun... |
2079 |
static int do_loopback(struct path *path, const char *old_name, |
2dafe1c4d reduce large do_m... |
2080 |
int recurse) |
1da177e4c Linux-2.6.12-rc2 |
2081 |
{ |
2d92ab3c6 [PATCH] finally g... |
2082 |
struct path old_path; |
84d17192d get rid of full-h... |
2083 2084 |
struct mount *mnt = NULL, *old, *parent; struct mountpoint *mp; |
57eccb830 mount: consolidat... |
2085 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2086 2087 |
if (!old_name || !*old_name) return -EINVAL; |
815d405ce VFS: Fix the rema... |
2088 |
err = kern_path(old_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path); |
1da177e4c Linux-2.6.12-rc2 |
2089 2090 |
if (err) return err; |
8823c079b vfs: Add setns su... |
2091 |
err = -EINVAL; |
4ce5d2b1a vfs: Don't copy m... |
2092 |
if (mnt_ns_loop(old_path.dentry)) |
dd111b31e VFS: Clean up whi... |
2093 |
goto out; |
8823c079b vfs: Add setns su... |
2094 |
|
84d17192d get rid of full-h... |
2095 2096 2097 |
mp = lock_mount(path); err = PTR_ERR(mp); if (IS_ERR(mp)) |
b12cea919 change the lockin... |
2098 |
goto out; |
87129cc0e vfs: spread struc... |
2099 |
old = real_mount(old_path.mnt); |
84d17192d get rid of full-h... |
2100 |
parent = real_mount(path->mnt); |
87129cc0e vfs: spread struc... |
2101 |
|
1da177e4c Linux-2.6.12-rc2 |
2102 |
err = -EINVAL; |
fc7be130c vfs: switch pnode... |
2103 |
if (IS_MNT_UNBINDABLE(old)) |
b12cea919 change the lockin... |
2104 |
goto out2; |
9676f0c63 [PATCH] unbindabl... |
2105 |
|
e149ed2b8 take the targets ... |
2106 2107 2108 2109 |
if (!check_mnt(parent)) goto out2; if (!check_mnt(old) && old_path.dentry->d_op != &ns_dentry_operations) |
b12cea919 change the lockin... |
2110 |
goto out2; |
1da177e4c Linux-2.6.12-rc2 |
2111 |
|
5ff9d8a65 vfs: Lock in plac... |
2112 2113 |
if (!recurse && has_locked_children(old, old_path.dentry)) goto out2; |
ccd48bc7f [PATCH] cleanups ... |
2114 |
if (recurse) |
4ce5d2b1a vfs: Don't copy m... |
2115 |
mnt = copy_tree(old, old_path.dentry, CL_COPY_MNT_NS_FILE); |
ccd48bc7f [PATCH] cleanups ... |
2116 |
else |
87129cc0e vfs: spread struc... |
2117 |
mnt = clone_mnt(old, old_path.dentry, 0); |
ccd48bc7f [PATCH] cleanups ... |
2118 |
|
be34d1a3b VFS: Make clone_m... |
2119 2120 |
if (IS_ERR(mnt)) { err = PTR_ERR(mnt); |
e9c5d8a56 mnt: release lock... |
2121 |
goto out2; |
be34d1a3b VFS: Make clone_m... |
2122 |
} |
ccd48bc7f [PATCH] cleanups ... |
2123 |
|
5ff9d8a65 vfs: Lock in plac... |
2124 |
mnt->mnt.mnt_flags &= ~MNT_LOCKED; |
84d17192d get rid of full-h... |
2125 |
err = graft_tree(mnt, parent, mp); |
ccd48bc7f [PATCH] cleanups ... |
2126 |
if (err) { |
719ea2fbb new helpers: lock... |
2127 |
lock_mount_hash(); |
e819f1521 mnt: Improve the ... |
2128 |
umount_tree(mnt, UMOUNT_SYNC); |
719ea2fbb new helpers: lock... |
2129 |
unlock_mount_hash(); |
5b83d2c5c [PATCH] sanitize ... |
2130 |
} |
b12cea919 change the lockin... |
2131 |
out2: |
84d17192d get rid of full-h... |
2132 |
unlock_mount(mp); |
ccd48bc7f [PATCH] cleanups ... |
2133 |
out: |
2d92ab3c6 [PATCH] finally g... |
2134 |
path_put(&old_path); |
1da177e4c Linux-2.6.12-rc2 |
2135 2136 |
return err; } |
2e4b7fcd9 [PATCH] r/o bind ... |
2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 |
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... |
2148 |
error = mnt_make_readonly(real_mount(mnt)); |
2e4b7fcd9 [PATCH] r/o bind ... |
2149 |
else |
83adc7532 vfs: spread struc... |
2150 |
__mnt_unmake_readonly(real_mount(mnt)); |
2e4b7fcd9 [PATCH] r/o bind ... |
2151 2152 |
return error; } |
1da177e4c Linux-2.6.12-rc2 |
2153 2154 2155 2156 2157 |
/* * 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... |
2158 2159 |
static int do_remount(struct path *path, int ms_flags, int sb_flags, int mnt_flags, void *data) |
1da177e4c Linux-2.6.12-rc2 |
2160 2161 |
{ int err; |
2d92ab3c6 [PATCH] finally g... |
2162 |
struct super_block *sb = path->mnt->mnt_sb; |
143c8c91c vfs: mnt_ns moved... |
2163 |
struct mount *mnt = real_mount(path->mnt); |
1da177e4c Linux-2.6.12-rc2 |
2164 |
|
143c8c91c vfs: mnt_ns moved... |
2165 |
if (!check_mnt(mnt)) |
1da177e4c Linux-2.6.12-rc2 |
2166 |
return -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2167 |
if (path->dentry != path->mnt->mnt_root) |
1da177e4c Linux-2.6.12-rc2 |
2168 |
return -EINVAL; |
07b645589 mnt: Move the tes... |
2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 |
/* 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... |
2179 2180 |
if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) && !(mnt_flags & MNT_NODEV)) { |
67690f937 userns: Remove im... |
2181 |
return -EPERM; |
9566d6742 mnt: Correct perm... |
2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 |
} 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... |
2195 2196 2197 |
err = security_sb_remount(sb, data); if (err) return err; |
1da177e4c Linux-2.6.12-rc2 |
2198 |
down_write(&sb->s_umount); |
e462ec50c VFS: Differentiat... |
2199 2200 |
if (ms_flags & MS_BIND) err = change_mount_flags(path->mnt, ms_flags); |
57eccb830 mount: consolidat... |
2201 2202 |
else if (!capable(CAP_SYS_ADMIN)) err = -EPERM; |
4aa98cf76 Push BKL down int... |
2203 |
else |
e462ec50c VFS: Differentiat... |
2204 |
err = do_remount_sb(sb, sb_flags, data, 0); |
7b43a79f3 mnt_flags fixes i... |
2205 |
if (!err) { |
719ea2fbb new helpers: lock... |
2206 |
lock_mount_hash(); |
a6138db81 mnt: Only change ... |
2207 |
mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK; |
143c8c91c vfs: mnt_ns moved... |
2208 |
mnt->mnt.mnt_flags = mnt_flags; |
143c8c91c vfs: mnt_ns moved... |
2209 |
touch_mnt_namespace(mnt->mnt_ns); |
719ea2fbb new helpers: lock... |
2210 |
unlock_mount_hash(); |
0e55a7cca [RFC PATCH] touch... |
2211 |
} |
6339dab86 do_remount(): pul... |
2212 |
up_write(&sb->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
2213 2214 |
return err; } |
cbbe362cd vfs: spread struc... |
2215 |
static inline int tree_contains_unbindable(struct mount *mnt) |
9676f0c63 [PATCH] unbindabl... |
2216 |
{ |
315fc83e5 vfs: spread struc... |
2217 |
struct mount *p; |
909b0a88e vfs: spread struc... |
2218 |
for (p = mnt; p; p = next_mnt(p, mnt)) { |
fc7be130c vfs: switch pnode... |
2219 |
if (IS_MNT_UNBINDABLE(p)) |
9676f0c63 [PATCH] unbindabl... |
2220 2221 2222 2223 |
return 1; } return 0; } |
808d4e3cf consitify do_moun... |
2224 |
static int do_move_mount(struct path *path, const char *old_name) |
1da177e4c Linux-2.6.12-rc2 |
2225 |
{ |
2d92ab3c6 [PATCH] finally g... |
2226 |
struct path old_path, parent_path; |
676da58df vfs: spread struc... |
2227 |
struct mount *p; |
0fb54e505 vfs: spread struc... |
2228 |
struct mount *old; |
84d17192d get rid of full-h... |
2229 |
struct mountpoint *mp; |
57eccb830 mount: consolidat... |
2230 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2231 2232 |
if (!old_name || !*old_name) return -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2233 |
err = kern_path(old_name, LOOKUP_FOLLOW, &old_path); |
1da177e4c Linux-2.6.12-rc2 |
2234 2235 |
if (err) return err; |
84d17192d get rid of full-h... |
2236 2237 2238 |
mp = lock_mount(path); err = PTR_ERR(mp); if (IS_ERR(mp)) |
cc53ce53c Add a dentry op t... |
2239 |
goto out; |
143c8c91c vfs: mnt_ns moved... |
2240 |
old = real_mount(old_path.mnt); |
fc7be130c vfs: switch pnode... |
2241 |
p = real_mount(path->mnt); |
143c8c91c vfs: mnt_ns moved... |
2242 |
|
1da177e4c Linux-2.6.12-rc2 |
2243 |
err = -EINVAL; |
fc7be130c vfs: switch pnode... |
2244 |
if (!check_mnt(p) || !check_mnt(old)) |
1da177e4c Linux-2.6.12-rc2 |
2245 |
goto out1; |
5ff9d8a65 vfs: Lock in plac... |
2246 2247 |
if (old->mnt.mnt_flags & MNT_LOCKED) goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2248 |
err = -EINVAL; |
2d92ab3c6 [PATCH] finally g... |
2249 |
if (old_path.dentry != old_path.mnt->mnt_root) |
214444032 [PATCH] shared mo... |
2250 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2251 |
|
676da58df vfs: spread struc... |
2252 |
if (!mnt_has_parent(old)) |
214444032 [PATCH] shared mo... |
2253 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2254 |
|
e36cb0b89 VFS: (Scripted) C... |
2255 2256 |
if (d_is_dir(path->dentry) != d_is_dir(old_path.dentry)) |
214444032 [PATCH] shared mo... |
2257 2258 2259 2260 |
goto out1; /* * Don't move a mount residing in a shared parent. */ |
fc7be130c vfs: switch pnode... |
2261 |
if (IS_MNT_SHARED(old->mnt_parent)) |
214444032 [PATCH] shared mo... |
2262 |
goto out1; |
9676f0c63 [PATCH] unbindabl... |
2263 2264 2265 2266 |
/* * Don't move a mount tree containing unbindable mounts to a destination * mount which is shared. */ |
fc7be130c vfs: switch pnode... |
2267 |
if (IS_MNT_SHARED(p) && tree_contains_unbindable(old)) |
9676f0c63 [PATCH] unbindabl... |
2268 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2269 |
err = -ELOOP; |
fc7be130c vfs: switch pnode... |
2270 |
for (; mnt_has_parent(p); p = p->mnt_parent) |
676da58df vfs: spread struc... |
2271 |
if (p == old) |
214444032 [PATCH] shared mo... |
2272 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2273 |
|
84d17192d get rid of full-h... |
2274 |
err = attach_recursive_mnt(old, real_mount(path->mnt), mp, &parent_path); |
4ac913785 Embed a struct pa... |
2275 |
if (err) |
214444032 [PATCH] shared mo... |
2276 |
goto out1; |
1da177e4c Linux-2.6.12-rc2 |
2277 2278 2279 |
/* if the mount is moved, it should no longer be expire * automatically */ |
6776db3d3 vfs: take mnt_sha... |
2280 |
list_del_init(&old->mnt_expire); |
1da177e4c Linux-2.6.12-rc2 |
2281 |
out1: |
84d17192d get rid of full-h... |
2282 |
unlock_mount(mp); |
1da177e4c Linux-2.6.12-rc2 |
2283 |
out: |
1da177e4c Linux-2.6.12-rc2 |
2284 |
if (!err) |
1a3906895 [PATCH] reduce st... |
2285 |
path_put(&parent_path); |
2d92ab3c6 [PATCH] finally g... |
2286 |
path_put(&old_path); |
1da177e4c Linux-2.6.12-rc2 |
2287 2288 |
return err; } |
9d412a43c vfs: split off vf... |
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 |
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... |
2311 2312 2313 |
/* * add a mount into a namespace's mount tree */ |
95bc5f25c vfs: spread struc... |
2314 |
static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags) |
9d412a43c vfs: split off vf... |
2315 |
{ |
84d17192d get rid of full-h... |
2316 2317 |
struct mountpoint *mp; struct mount *parent; |
9d412a43c vfs: split off vf... |
2318 |
int err; |
f2ebb3a92 smarter propagate... |
2319 |
mnt_flags &= ~MNT_INTERNAL_FLAGS; |
9d412a43c vfs: split off vf... |
2320 |
|
84d17192d get rid of full-h... |
2321 2322 2323 |
mp = lock_mount(path); if (IS_ERR(mp)) return PTR_ERR(mp); |
9d412a43c vfs: split off vf... |
2324 |
|
84d17192d get rid of full-h... |
2325 |
parent = real_mount(path->mnt); |
9d412a43c vfs: split off vf... |
2326 |
err = -EINVAL; |
84d17192d get rid of full-h... |
2327 |
if (unlikely(!check_mnt(parent))) { |
156cacb1d do_add_mount()/um... |
2328 2329 2330 2331 |
/* 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... |
2332 |
if (!parent->mnt_ns) |
156cacb1d do_add_mount()/um... |
2333 2334 |
goto unlock; } |
9d412a43c vfs: split off vf... |
2335 2336 2337 |
/* Refuse the same filesystem on the same mount point */ err = -EBUSY; |
95bc5f25c vfs: spread struc... |
2338 |
if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb && |
9d412a43c vfs: split off vf... |
2339 2340 2341 2342 |
path->mnt->mnt_root == path->dentry) goto unlock; err = -EINVAL; |
e36cb0b89 VFS: (Scripted) C... |
2343 |
if (d_is_symlink(newmnt->mnt.mnt_root)) |
9d412a43c vfs: split off vf... |
2344 |
goto unlock; |
95bc5f25c vfs: spread struc... |
2345 |
newmnt->mnt.mnt_flags = mnt_flags; |
84d17192d get rid of full-h... |
2346 |
err = graft_tree(newmnt, parent, mp); |
9d412a43c vfs: split off vf... |
2347 2348 |
unlock: |
84d17192d get rid of full-h... |
2349 |
unlock_mount(mp); |
9d412a43c vfs: split off vf... |
2350 2351 |
return err; } |
b1e75df45 tidy up around fi... |
2352 |
|
8654df4e2 mnt: Refactor fs_... |
2353 |
static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags); |
1b852bceb mnt: Refactor the... |
2354 |
|
1da177e4c Linux-2.6.12-rc2 |
2355 2356 2357 2358 |
/* * create a new mount for userspace and request it to be added into the * namespace's tree */ |
e462ec50c VFS: Differentiat... |
2359 |
static int do_new_mount(struct path *path, const char *fstype, int sb_flags, |
808d4e3cf consitify do_moun... |
2360 |
int mnt_flags, const char *name, void *data) |
1da177e4c Linux-2.6.12-rc2 |
2361 |
{ |
0c55cfc41 vfs: Allow unpriv... |
2362 |
struct file_system_type *type; |
1da177e4c Linux-2.6.12-rc2 |
2363 |
struct vfsmount *mnt; |
15f9a3f3e don't drop newmnt... |
2364 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
2365 |
|
0c55cfc41 vfs: Allow unpriv... |
2366 |
if (!fstype) |
1da177e4c Linux-2.6.12-rc2 |
2367 |
return -EINVAL; |
0c55cfc41 vfs: Allow unpriv... |
2368 2369 2370 |
type = get_fs_type(fstype); if (!type) return -ENODEV; |
e462ec50c VFS: Differentiat... |
2371 |
mnt = vfs_kern_mount(type, sb_flags, name, data); |
0c55cfc41 vfs: Allow unpriv... |
2372 2373 2374 2375 2376 |
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 |
2377 2378 |
if (IS_ERR(mnt)) return PTR_ERR(mnt); |
8654df4e2 mnt: Refactor fs_... |
2379 2380 2381 2382 |
if (mount_too_revealing(mnt, &mnt_flags)) { mntput(mnt); return -EPERM; } |
95bc5f25c vfs: spread struc... |
2383 |
err = do_add_mount(real_mount(mnt), path, mnt_flags); |
15f9a3f3e don't drop newmnt... |
2384 2385 2386 |
if (err) mntput(mnt); return err; |
1da177e4c Linux-2.6.12-rc2 |
2387 |
} |
19a167af7 Take the completi... |
2388 2389 |
int finish_automount(struct vfsmount *m, struct path *path) { |
6776db3d3 vfs: take mnt_sha... |
2390 |
struct mount *mnt = real_mount(m); |
19a167af7 Take the completi... |
2391 2392 2393 2394 |
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... |
2395 |
BUG_ON(mnt_get_count(mnt) < 2); |
19a167af7 Take the completi... |
2396 2397 2398 |
if (m->mnt_sb == path->mnt->mnt_sb && m->mnt_root == path->dentry) { |
b1e75df45 tidy up around fi... |
2399 2400 |
err = -ELOOP; goto fail; |
19a167af7 Take the completi... |
2401 |
} |
95bc5f25c vfs: spread struc... |
2402 |
err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE); |
b1e75df45 tidy up around fi... |
2403 2404 2405 2406 |
if (!err) return 0; fail: /* remove m from any expiration list it may be on */ |
6776db3d3 vfs: take mnt_sha... |
2407 |
if (!list_empty(&mnt->mnt_expire)) { |
97216be09 fold release_moun... |
2408 |
namespace_lock(); |
6776db3d3 vfs: take mnt_sha... |
2409 |
list_del_init(&mnt->mnt_expire); |
97216be09 fold release_moun... |
2410 |
namespace_unlock(); |
19a167af7 Take the completi... |
2411 |
} |
b1e75df45 tidy up around fi... |
2412 2413 |
mntput(m); mntput(m); |
19a167af7 Take the completi... |
2414 2415 |
return err; } |
ea5b778a8 Unexport do_add_m... |
2416 2417 2418 2419 2420 2421 2422 |
/** * 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... |
2423 |
namespace_lock(); |
ea5b778a8 Unexport do_add_m... |
2424 |
|
6776db3d3 vfs: take mnt_sha... |
2425 |
list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list); |
ea5b778a8 Unexport do_add_m... |
2426 |
|
97216be09 fold release_moun... |
2427 |
namespace_unlock(); |
ea5b778a8 Unexport do_add_m... |
2428 2429 2430 2431 |
} EXPORT_SYMBOL(mnt_set_expiry); /* |
1da177e4c Linux-2.6.12-rc2 |
2432 2433 2434 2435 2436 2437 |
* 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... |
2438 |
struct mount *mnt, *next; |
1da177e4c Linux-2.6.12-rc2 |
2439 2440 2441 2442 |
LIST_HEAD(graveyard); if (list_empty(mounts)) return; |
97216be09 fold release_moun... |
2443 |
namespace_lock(); |
719ea2fbb new helpers: lock... |
2444 |
lock_mount_hash(); |
1da177e4c Linux-2.6.12-rc2 |
2445 2446 2447 2448 2449 2450 2451 |
/* 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... |
2452 |
list_for_each_entry_safe(mnt, next, mounts, mnt_expire) { |
863d684f9 vfs: move the res... |
2453 |
if (!xchg(&mnt->mnt_expiry_mark, 1) || |
1ab597386 vfs: spread struc... |
2454 |
propagate_mount_busy(mnt, 1)) |
1da177e4c Linux-2.6.12-rc2 |
2455 |
continue; |
6776db3d3 vfs: take mnt_sha... |
2456 |
list_move(&mnt->mnt_expire, &graveyard); |
1da177e4c Linux-2.6.12-rc2 |
2457 |
} |
bcc5c7d2b [PATCH] sanitize ... |
2458 |
while (!list_empty(&graveyard)) { |
6776db3d3 vfs: take mnt_sha... |
2459 |
mnt = list_first_entry(&graveyard, struct mount, mnt_expire); |
143c8c91c vfs: mnt_ns moved... |
2460 |
touch_mnt_namespace(mnt->mnt_ns); |
e819f1521 mnt: Improve the ... |
2461 |
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
bcc5c7d2b [PATCH] sanitize ... |
2462 |
} |
719ea2fbb new helpers: lock... |
2463 |
unlock_mount_hash(); |
3ab6abee5 more conversions ... |
2464 |
namespace_unlock(); |
5528f911b VFS: Add shrink_s... |
2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 |
} 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... |
2475 |
static int select_submounts(struct mount *parent, struct list_head *graveyard) |
5528f911b VFS: Add shrink_s... |
2476 |
{ |
692afc312 vfs: spread struc... |
2477 |
struct mount *this_parent = parent; |
5528f911b VFS: Add shrink_s... |
2478 2479 2480 2481 |
struct list_head *next; int found = 0; repeat: |
6b41d536f vfs: take mnt_chi... |
2482 |
next = this_parent->mnt_mounts.next; |
5528f911b VFS: Add shrink_s... |
2483 |
resume: |
6b41d536f vfs: take mnt_chi... |
2484 |
while (next != &this_parent->mnt_mounts) { |
5528f911b VFS: Add shrink_s... |
2485 |
struct list_head *tmp = next; |
6b41d536f vfs: take mnt_chi... |
2486 |
struct mount *mnt = list_entry(tmp, struct mount, mnt_child); |
5528f911b VFS: Add shrink_s... |
2487 2488 |
next = tmp->next; |
692afc312 vfs: spread struc... |
2489 |
if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE)) |
1da177e4c Linux-2.6.12-rc2 |
2490 |
continue; |
5528f911b VFS: Add shrink_s... |
2491 2492 2493 |
/* * Descend a level if the d_mounts list is non-empty. */ |
6b41d536f vfs: take mnt_chi... |
2494 |
if (!list_empty(&mnt->mnt_mounts)) { |
5528f911b VFS: Add shrink_s... |
2495 2496 2497 |
this_parent = mnt; goto repeat; } |
1da177e4c Linux-2.6.12-rc2 |
2498 |
|
1ab597386 vfs: spread struc... |
2499 |
if (!propagate_mount_busy(mnt, 1)) { |
6776db3d3 vfs: take mnt_sha... |
2500 |
list_move_tail(&mnt->mnt_expire, graveyard); |
5528f911b VFS: Add shrink_s... |
2501 2502 |
found++; } |
1da177e4c Linux-2.6.12-rc2 |
2503 |
} |
5528f911b VFS: Add shrink_s... |
2504 2505 2506 2507 |
/* * All done at this level ... ascend and resume the search */ if (this_parent != parent) { |
6b41d536f vfs: take mnt_chi... |
2508 |
next = this_parent->mnt_child.next; |
0714a5338 vfs: now it can b... |
2509 |
this_parent = this_parent->mnt_parent; |
5528f911b VFS: Add shrink_s... |
2510 2511 2512 2513 2514 2515 2516 2517 |
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... |
2518 |
* |
48a066e72 RCU'd vfsmounts |
2519 |
* mount_lock must be held for write |
5528f911b VFS: Add shrink_s... |
2520 |
*/ |
b54b9be78 get rid of the se... |
2521 |
static void shrink_submounts(struct mount *mnt) |
5528f911b VFS: Add shrink_s... |
2522 2523 |
{ LIST_HEAD(graveyard); |
761d5c38e vfs: spread struc... |
2524 |
struct mount *m; |
5528f911b VFS: Add shrink_s... |
2525 |
|
5528f911b VFS: Add shrink_s... |
2526 |
/* extract submounts of 'mountpoint' from the expiration list */ |
c35038bec [PATCH] do shrink... |
2527 |
while (select_submounts(mnt, &graveyard)) { |
bcc5c7d2b [PATCH] sanitize ... |
2528 |
while (!list_empty(&graveyard)) { |
761d5c38e vfs: spread struc... |
2529 |
m = list_first_entry(&graveyard, struct mount, |
6776db3d3 vfs: take mnt_sha... |
2530 |
mnt_expire); |
143c8c91c vfs: mnt_ns moved... |
2531 |
touch_mnt_namespace(m->mnt_ns); |
e819f1521 mnt: Improve the ... |
2532 |
umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC); |
bcc5c7d2b [PATCH] sanitize ... |
2533 2534 |
} } |
1da177e4c Linux-2.6.12-rc2 |
2535 |
} |
1da177e4c Linux-2.6.12-rc2 |
2536 2537 2538 2539 2540 2541 |
/* * 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... |
2542 2543 |
static long exact_copy_from_user(void *to, const void __user * from, unsigned long n) |
1da177e4c Linux-2.6.12-rc2 |
2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 |
{ 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... |
2563 |
void *copy_mount_options(const void __user * data) |
1da177e4c Linux-2.6.12-rc2 |
2564 2565 |
{ int i; |
1da177e4c Linux-2.6.12-rc2 |
2566 |
unsigned long size; |
b40ef8696 saner calling con... |
2567 |
char *copy; |
b58fed8b1 [PATCH] lindent f... |
2568 |
|
1da177e4c Linux-2.6.12-rc2 |
2569 |
if (!data) |
b40ef8696 saner calling con... |
2570 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
2571 |
|
b40ef8696 saner calling con... |
2572 2573 2574 |
copy = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!copy) return ERR_PTR(-ENOMEM); |
1da177e4c Linux-2.6.12-rc2 |
2575 2576 2577 2578 2579 2580 2581 2582 2583 |
/* 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... |
2584 |
i = size - exact_copy_from_user(copy, data, size); |
1da177e4c Linux-2.6.12-rc2 |
2585 |
if (!i) { |
b40ef8696 saner calling con... |
2586 2587 |
kfree(copy); return ERR_PTR(-EFAULT); |
1da177e4c Linux-2.6.12-rc2 |
2588 2589 |
} if (i != PAGE_SIZE) |
b40ef8696 saner calling con... |
2590 2591 |
memset(copy + i, 0, PAGE_SIZE - i); return copy; |
1da177e4c Linux-2.6.12-rc2 |
2592 |
} |
b8850d1fa fs: namespace: su... |
2593 |
char *copy_mount_string(const void __user *data) |
eca6f534e fs: fix overflow ... |
2594 |
{ |
b8850d1fa fs: namespace: su... |
2595 |
return data ? strndup_user(data, PAGE_SIZE) : NULL; |
eca6f534e fs: fix overflow ... |
2596 |
} |
1da177e4c Linux-2.6.12-rc2 |
2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 |
/* * 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... |
2611 |
long do_mount(const char *dev_name, const char __user *dir_name, |
808d4e3cf consitify do_moun... |
2612 |
const char *type_page, unsigned long flags, void *data_page) |
1da177e4c Linux-2.6.12-rc2 |
2613 |
{ |
2d92ab3c6 [PATCH] finally g... |
2614 |
struct path path; |
e462ec50c VFS: Differentiat... |
2615 |
unsigned int mnt_flags = 0, sb_flags; |
1da177e4c Linux-2.6.12-rc2 |
2616 |
int retval = 0; |
1da177e4c Linux-2.6.12-rc2 |
2617 2618 2619 2620 2621 2622 |
/* Discard magic */ if ((flags & MS_MGC_MSK) == MS_MGC_VAL) flags &= ~MS_MGC_MSK; /* Basic sanity checks */ |
1da177e4c Linux-2.6.12-rc2 |
2623 2624 |
if (data_page) ((char *)data_page)[PAGE_SIZE - 1] = 0; |
e462ec50c VFS: Differentiat... |
2625 2626 |
if (flags & MS_NOUSER) return -EINVAL; |
a27ab9f26 LSM: Pass origina... |
2627 |
/* ... and get the mountpoint */ |
5e6123f34 vfs: move getname... |
2628 |
retval = user_path(dir_name, &path); |
a27ab9f26 LSM: Pass origina... |
2629 2630 2631 2632 2633 |
if (retval) return retval; retval = security_sb_mount(dev_name, &path, type_page, flags, data_page); |
0d5cadb87 do_mount(): fix a... |
2634 2635 |
if (!retval && !may_mount()) retval = -EPERM; |
e462ec50c VFS: Differentiat... |
2636 |
if (!retval && (flags & SB_MANDLOCK) && !may_mandlock()) |
9e8925b67 locks: Allow disa... |
2637 |
retval = -EPERM; |
a27ab9f26 LSM: Pass origina... |
2638 2639 |
if (retval) goto dput_out; |
613cbe3d4 Don't set relatim... |
2640 2641 2642 |
/* Default to relatime unless overriden */ if (!(flags & MS_NOATIME)) mnt_flags |= MNT_RELATIME; |
0a1c01c94 Make relatime def... |
2643 |
|
1da177e4c Linux-2.6.12-rc2 |
2644 2645 2646 2647 2648 2649 2650 |
/* 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... |
2651 2652 2653 2654 |
if (flags & MS_NOATIME) mnt_flags |= MNT_NOATIME; if (flags & MS_NODIRATIME) mnt_flags |= MNT_NODIRATIME; |
d0adde574 Add a strictatime... |
2655 2656 |
if (flags & MS_STRICTATIME) mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME); |
e462ec50c VFS: Differentiat... |
2657 |
if (flags & SB_RDONLY) |
2e4b7fcd9 [PATCH] r/o bind ... |
2658 |
mnt_flags |= MNT_READONLY; |
fc33a7bb9 [PATCH] per-mount... |
2659 |
|
ffbc6f0ea mnt: Change the d... |
2660 2661 2662 2663 2664 2665 2666 |
/* 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... |
2667 2668 2669 2670 2671 |
sb_flags = flags & (SB_RDONLY | SB_SYNCHRONOUS | SB_MANDLOCK | SB_DIRSYNC | SB_SILENT | |
917086ff2 vfs: fix mounting... |
2672 2673 |
SB_POSIXACL | SB_I_VERSION); |
1da177e4c Linux-2.6.12-rc2 |
2674 |
|
1da177e4c Linux-2.6.12-rc2 |
2675 |
if (flags & MS_REMOUNT) |
e462ec50c VFS: Differentiat... |
2676 |
retval = do_remount(&path, flags, sb_flags, mnt_flags, |
1da177e4c Linux-2.6.12-rc2 |
2677 2678 |
data_page); else if (flags & MS_BIND) |
2d92ab3c6 [PATCH] finally g... |
2679 |
retval = do_loopback(&path, dev_name, flags & MS_REC); |
9676f0c63 [PATCH] unbindabl... |
2680 |
else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) |
2d92ab3c6 [PATCH] finally g... |
2681 |
retval = do_change_type(&path, flags); |
1da177e4c Linux-2.6.12-rc2 |
2682 |
else if (flags & MS_MOVE) |
2d92ab3c6 [PATCH] finally g... |
2683 |
retval = do_move_mount(&path, dev_name); |
1da177e4c Linux-2.6.12-rc2 |
2684 |
else |
e462ec50c VFS: Differentiat... |
2685 |
retval = do_new_mount(&path, type_page, sb_flags, mnt_flags, |
1da177e4c Linux-2.6.12-rc2 |
2686 2687 |
dev_name, data_page); dput_out: |
2d92ab3c6 [PATCH] finally g... |
2688 |
path_put(&path); |
1da177e4c Linux-2.6.12-rc2 |
2689 2690 |
return retval; } |
537f7ccb3 mntns: Add a limi... |
2691 2692 2693 2694 2695 2696 2697 2698 2699 |
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... |
2700 2701 |
static void free_mnt_ns(struct mnt_namespace *ns) { |
6344c433a new helpers: ns_a... |
2702 |
ns_free_inum(&ns->ns); |
537f7ccb3 mntns: Add a limi... |
2703 |
dec_mnt_namespaces(ns->ucounts); |
771b13716 vfs: Add a user n... |
2704 2705 2706 |
put_user_ns(ns->user_ns); kfree(ns); } |
8823c079b vfs: Add setns su... |
2707 2708 2709 2710 2711 2712 2713 2714 |
/* * 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... |
2715 |
static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) |
cf8d2c11c VFS: Add VFS help... |
2716 2717 |
{ struct mnt_namespace *new_ns; |
537f7ccb3 mntns: Add a limi... |
2718 |
struct ucounts *ucounts; |
98f842e67 proc: Usable inod... |
2719 |
int ret; |
cf8d2c11c VFS: Add VFS help... |
2720 |
|
537f7ccb3 mntns: Add a limi... |
2721 2722 |
ucounts = inc_mnt_namespaces(user_ns); if (!ucounts) |
df75e7748 userns: When the ... |
2723 |
return ERR_PTR(-ENOSPC); |
537f7ccb3 mntns: Add a limi... |
2724 |
|
cf8d2c11c VFS: Add VFS help... |
2725 |
new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); |
537f7ccb3 mntns: Add a limi... |
2726 2727 |
if (!new_ns) { dec_mnt_namespaces(ucounts); |
cf8d2c11c VFS: Add VFS help... |
2728 |
return ERR_PTR(-ENOMEM); |
537f7ccb3 mntns: Add a limi... |
2729 |
} |
6344c433a new helpers: ns_a... |
2730 |
ret = ns_alloc_inum(&new_ns->ns); |
98f842e67 proc: Usable inod... |
2731 2732 |
if (ret) { kfree(new_ns); |
537f7ccb3 mntns: Add a limi... |
2733 |
dec_mnt_namespaces(ucounts); |
98f842e67 proc: Usable inod... |
2734 2735 |
return ERR_PTR(ret); } |
33c429405 copy address of p... |
2736 |
new_ns->ns.ops = &mntns_operations; |
8823c079b vfs: Add setns su... |
2737 |
new_ns->seq = atomic64_add_return(1, &mnt_ns_seq); |
cf8d2c11c VFS: Add VFS help... |
2738 2739 2740 2741 2742 |
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... |
2743 |
new_ns->user_ns = get_user_ns(user_ns); |
537f7ccb3 mntns: Add a limi... |
2744 |
new_ns->ucounts = ucounts; |
d29216842 mnt: Add a per mo... |
2745 2746 |
new_ns->mounts = 0; new_ns->pending_mounts = 0; |
cf8d2c11c VFS: Add VFS help... |
2747 2748 |
return new_ns; } |
0766f788e latent_entropy: M... |
2749 |
__latent_entropy |
9559f6891 fold dup_mnt_ns()... |
2750 2751 |
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 |
2752 |
{ |
6b3286ed1 [PATCH] rename st... |
2753 |
struct mnt_namespace *new_ns; |
7f2da1e7d [PATCH] kill altroot |
2754 |
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL; |
315fc83e5 vfs: spread struc... |
2755 |
struct mount *p, *q; |
9559f6891 fold dup_mnt_ns()... |
2756 |
struct mount *old; |
cb338d06e vfs: spread struc... |
2757 |
struct mount *new; |
7a472ef4b vfs: Only support... |
2758 |
int copy_flags; |
1da177e4c Linux-2.6.12-rc2 |
2759 |
|
9559f6891 fold dup_mnt_ns()... |
2760 2761 2762 2763 2764 2765 2766 2767 |
BUG_ON(!ns); if (likely(!(flags & CLONE_NEWNS))) { get_mnt_ns(ns); return ns; } old = ns->root; |
771b13716 vfs: Add a user n... |
2768 |
new_ns = alloc_mnt_ns(user_ns); |
cf8d2c11c VFS: Add VFS help... |
2769 2770 |
if (IS_ERR(new_ns)) return new_ns; |
1da177e4c Linux-2.6.12-rc2 |
2771 |
|
97216be09 fold release_moun... |
2772 |
namespace_lock(); |
1da177e4c Linux-2.6.12-rc2 |
2773 |
/* First pass: copy the tree topology */ |
4ce5d2b1a vfs: Don't copy m... |
2774 |
copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE; |
9559f6891 fold dup_mnt_ns()... |
2775 |
if (user_ns != ns->user_ns) |
132c94e31 vfs: Carefully pr... |
2776 |
copy_flags |= CL_SHARED_TO_SLAVE | CL_UNPRIVILEGED; |
7a472ef4b vfs: Only support... |
2777 |
new = copy_tree(old, old->mnt.mnt_root, copy_flags); |
be34d1a3b VFS: Make clone_m... |
2778 |
if (IS_ERR(new)) { |
328e6d901 switch unlock_mou... |
2779 |
namespace_unlock(); |
771b13716 vfs: Add a user n... |
2780 |
free_mnt_ns(new_ns); |
be34d1a3b VFS: Make clone_m... |
2781 |
return ERR_CAST(new); |
1da177e4c Linux-2.6.12-rc2 |
2782 |
} |
be08d6d26 switch mnt_namesp... |
2783 |
new_ns->root = new; |
1a4eeaf2a vfs: move mnt_lis... |
2784 |
list_add_tail(&new_ns->list, &new->mnt_list); |
1da177e4c Linux-2.6.12-rc2 |
2785 2786 2787 2788 2789 2790 |
/* * 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... |
2791 |
p = old; |
cb338d06e vfs: spread struc... |
2792 |
q = new; |
1da177e4c Linux-2.6.12-rc2 |
2793 |
while (p) { |
143c8c91c vfs: mnt_ns moved... |
2794 |
q->mnt_ns = new_ns; |
d29216842 mnt: Add a per mo... |
2795 |
new_ns->mounts++; |
9559f6891 fold dup_mnt_ns()... |
2796 2797 2798 |
if (new_fs) { if (&p->mnt == new_fs->root.mnt) { new_fs->root.mnt = mntget(&q->mnt); |
315fc83e5 vfs: spread struc... |
2799 |
rootmnt = &p->mnt; |
1da177e4c Linux-2.6.12-rc2 |
2800 |
} |
9559f6891 fold dup_mnt_ns()... |
2801 2802 |
if (&p->mnt == new_fs->pwd.mnt) { new_fs->pwd.mnt = mntget(&q->mnt); |
315fc83e5 vfs: spread struc... |
2803 |
pwdmnt = &p->mnt; |
1da177e4c Linux-2.6.12-rc2 |
2804 |
} |
1da177e4c Linux-2.6.12-rc2 |
2805 |
} |
909b0a88e vfs: spread struc... |
2806 2807 |
p = next_mnt(p, old); q = next_mnt(q, new); |
4ce5d2b1a vfs: Don't copy m... |
2808 2809 2810 2811 |
if (!q) break; while (p->mnt.mnt_root != q->mnt.mnt_root) p = next_mnt(p, old); |
1da177e4c Linux-2.6.12-rc2 |
2812 |
} |
328e6d901 switch unlock_mou... |
2813 |
namespace_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
2814 |
|
1da177e4c Linux-2.6.12-rc2 |
2815 |
if (rootmnt) |
f03c65993 sanitize vfsmount... |
2816 |
mntput(rootmnt); |
1da177e4c Linux-2.6.12-rc2 |
2817 |
if (pwdmnt) |
f03c65993 sanitize vfsmount... |
2818 |
mntput(pwdmnt); |
1da177e4c Linux-2.6.12-rc2 |
2819 |
|
741a29513 [PATCH] unshare s... |
2820 |
return new_ns; |
1da177e4c Linux-2.6.12-rc2 |
2821 |
} |
cf8d2c11c VFS: Add VFS help... |
2822 2823 2824 2825 |
/** * 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... |
2826 |
static struct mnt_namespace *create_mnt_ns(struct vfsmount *m) |
cf8d2c11c VFS: Add VFS help... |
2827 |
{ |
771b13716 vfs: Add a user n... |
2828 |
struct mnt_namespace *new_ns = alloc_mnt_ns(&init_user_ns); |
cf8d2c11c VFS: Add VFS help... |
2829 |
if (!IS_ERR(new_ns)) { |
1a4eeaf2a vfs: move mnt_lis... |
2830 2831 |
struct mount *mnt = real_mount(m); mnt->mnt_ns = new_ns; |
be08d6d26 switch mnt_namesp... |
2832 |
new_ns->root = mnt; |
d29216842 mnt: Add a per mo... |
2833 |
new_ns->mounts++; |
b1983cd89 create_mnt_ns: un... |
2834 |
list_add(&mnt->mnt_list, &new_ns->list); |
c13344958 switch create_mnt... |
2835 |
} else { |
1a4eeaf2a vfs: move mnt_lis... |
2836 |
mntput(m); |
cf8d2c11c VFS: Add VFS help... |
2837 2838 2839 |
} return new_ns; } |
cf8d2c11c VFS: Add VFS help... |
2840 |
|
ea441d110 new helper: mount... |
2841 2842 2843 |
struct dentry *mount_subtree(struct vfsmount *mnt, const char *name) { struct mnt_namespace *ns; |
d31da0f0b mount_subtree() p... |
2844 |
struct super_block *s; |
ea441d110 new helper: mount... |
2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 |
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... |
2861 2862 |
s = path.mnt->mnt_sb; atomic_inc(&s->s_active); |
ea441d110 new helper: mount... |
2863 2864 |
mntput(path.mnt); /* lock the sucker */ |
d31da0f0b mount_subtree() p... |
2865 |
down_write(&s->s_umount); |
ea441d110 new helper: mount... |
2866 2867 2868 2869 |
/* ... and return the root of (sub)tree on it */ return path.dentry; } EXPORT_SYMBOL(mount_subtree); |
bdc480e3b [CVE-2009-0029] S... |
2870 2871 |
SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name, char __user *, type, unsigned long, flags, void __user *, data) |
1da177e4c Linux-2.6.12-rc2 |
2872 |
{ |
eca6f534e fs: fix overflow ... |
2873 2874 |
int ret; char *kernel_type; |
eca6f534e fs: fix overflow ... |
2875 |
char *kernel_dev; |
b40ef8696 saner calling con... |
2876 |
void *options; |
1da177e4c Linux-2.6.12-rc2 |
2877 |
|
b8850d1fa fs: namespace: su... |
2878 2879 2880 |
kernel_type = copy_mount_string(type); ret = PTR_ERR(kernel_type); if (IS_ERR(kernel_type)) |
eca6f534e fs: fix overflow ... |
2881 |
goto out_type; |
1da177e4c Linux-2.6.12-rc2 |
2882 |
|
b8850d1fa fs: namespace: su... |
2883 2884 2885 |
kernel_dev = copy_mount_string(dev_name); ret = PTR_ERR(kernel_dev); if (IS_ERR(kernel_dev)) |
eca6f534e fs: fix overflow ... |
2886 |
goto out_dev; |
1da177e4c Linux-2.6.12-rc2 |
2887 |
|
b40ef8696 saner calling con... |
2888 2889 2890 |
options = copy_mount_options(data); ret = PTR_ERR(options); if (IS_ERR(options)) |
eca6f534e fs: fix overflow ... |
2891 |
goto out_data; |
1da177e4c Linux-2.6.12-rc2 |
2892 |
|
b40ef8696 saner calling con... |
2893 |
ret = do_mount(kernel_dev, dir_name, kernel_type, flags, options); |
1da177e4c Linux-2.6.12-rc2 |
2894 |
|
b40ef8696 saner calling con... |
2895 |
kfree(options); |
eca6f534e fs: fix overflow ... |
2896 2897 2898 |
out_data: kfree(kernel_dev); out_dev: |
eca6f534e fs: fix overflow ... |
2899 2900 2901 |
kfree(kernel_type); out_type: return ret; |
1da177e4c Linux-2.6.12-rc2 |
2902 2903 2904 |
} /* |
afac7cba7 vfs: more mnt_par... |
2905 2906 |
* Return true if path is reachable from root * |
48a066e72 RCU'd vfsmounts |
2907 |
* namespace_sem or mount_lock is held |
afac7cba7 vfs: more mnt_par... |
2908 |
*/ |
643822b41 vfs: spread struc... |
2909 |
bool is_path_reachable(struct mount *mnt, struct dentry *dentry, |
afac7cba7 vfs: more mnt_par... |
2910 2911 |
const struct path *root) { |
643822b41 vfs: spread struc... |
2912 |
while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) { |
a73324da7 vfs: move mnt_mou... |
2913 |
dentry = mnt->mnt_mountpoint; |
0714a5338 vfs: now it can b... |
2914 |
mnt = mnt->mnt_parent; |
afac7cba7 vfs: more mnt_par... |
2915 |
} |
643822b41 vfs: spread struc... |
2916 |
return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry); |
afac7cba7 vfs: more mnt_par... |
2917 |
} |
640eb7e7b fs: Constify path... |
2918 |
bool path_is_under(const struct path *path1, const struct path *path2) |
afac7cba7 vfs: more mnt_par... |
2919 |
{ |
25ab4c9b1 fs/namespace.c: p... |
2920 |
bool res; |
48a066e72 RCU'd vfsmounts |
2921 |
read_seqlock_excl(&mount_lock); |
643822b41 vfs: spread struc... |
2922 |
res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2); |
48a066e72 RCU'd vfsmounts |
2923 |
read_sequnlock_excl(&mount_lock); |
afac7cba7 vfs: more mnt_par... |
2924 2925 2926 2927 2928 |
return res; } EXPORT_SYMBOL(path_is_under); /* |
1da177e4c Linux-2.6.12-rc2 |
2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 |
* 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... |
2941 2942 2943 2944 |
* 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 |
2945 2946 2947 2948 2949 2950 2951 2952 |
* 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... |
2953 2954 |
SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, const char __user *, put_old) |
1da177e4c Linux-2.6.12-rc2 |
2955 |
{ |
2d8f30380 [PATCH] sanitize ... |
2956 |
struct path new, old, parent_path, root_parent, root; |
84d17192d get rid of full-h... |
2957 2958 |
struct mount *new_mnt, *root_mnt, *old_mnt; struct mountpoint *old_mp, *root_mp; |
1da177e4c Linux-2.6.12-rc2 |
2959 |
int error; |
9b40bc90a get rid of unprot... |
2960 |
if (!may_mount()) |
1da177e4c Linux-2.6.12-rc2 |
2961 |
return -EPERM; |
2d8f30380 [PATCH] sanitize ... |
2962 |
error = user_path_dir(new_root, &new); |
1da177e4c Linux-2.6.12-rc2 |
2963 2964 |
if (error) goto out0; |
1da177e4c Linux-2.6.12-rc2 |
2965 |
|
2d8f30380 [PATCH] sanitize ... |
2966 |
error = user_path_dir(put_old, &old); |
1da177e4c Linux-2.6.12-rc2 |
2967 2968 |
if (error) goto out1; |
2d8f30380 [PATCH] sanitize ... |
2969 |
error = security_sb_pivotroot(&old, &new); |
b12cea919 change the lockin... |
2970 2971 |
if (error) goto out2; |
1da177e4c Linux-2.6.12-rc2 |
2972 |
|
f7ad3c6be vfs: add helpers ... |
2973 |
get_fs_root(current->fs, &root); |
84d17192d get rid of full-h... |
2974 2975 2976 |
old_mp = lock_mount(&old); error = PTR_ERR(old_mp); if (IS_ERR(old_mp)) |
b12cea919 change the lockin... |
2977 |
goto out3; |
1da177e4c Linux-2.6.12-rc2 |
2978 |
error = -EINVAL; |
419148da6 vfs: spread struc... |
2979 2980 |
new_mnt = real_mount(new.mnt); root_mnt = real_mount(root.mnt); |
84d17192d get rid of full-h... |
2981 2982 |
old_mnt = real_mount(old.mnt); if (IS_MNT_SHARED(old_mnt) || |
fc7be130c vfs: switch pnode... |
2983 2984 |
IS_MNT_SHARED(new_mnt->mnt_parent) || IS_MNT_SHARED(root_mnt->mnt_parent)) |
b12cea919 change the lockin... |
2985 |
goto out4; |
143c8c91c vfs: mnt_ns moved... |
2986 |
if (!check_mnt(root_mnt) || !check_mnt(new_mnt)) |
b12cea919 change the lockin... |
2987 |
goto out4; |
5ff9d8a65 vfs: Lock in plac... |
2988 2989 |
if (new_mnt->mnt.mnt_flags & MNT_LOCKED) goto out4; |
1da177e4c Linux-2.6.12-rc2 |
2990 |
error = -ENOENT; |
f3da392e9 dcache: extrace a... |
2991 |
if (d_unlinked(new.dentry)) |
b12cea919 change the lockin... |
2992 |
goto out4; |
1da177e4c Linux-2.6.12-rc2 |
2993 |
error = -EBUSY; |
84d17192d get rid of full-h... |
2994 |
if (new_mnt == root_mnt || old_mnt == root_mnt) |
b12cea919 change the lockin... |
2995 |
goto out4; /* loop, on the same file system */ |
1da177e4c Linux-2.6.12-rc2 |
2996 |
error = -EINVAL; |
8c3ee42e8 [PATCH] get rid o... |
2997 |
if (root.mnt->mnt_root != root.dentry) |
b12cea919 change the lockin... |
2998 |
goto out4; /* not a mountpoint */ |
676da58df vfs: spread struc... |
2999 |
if (!mnt_has_parent(root_mnt)) |
b12cea919 change the lockin... |
3000 |
goto out4; /* not attached */ |
84d17192d get rid of full-h... |
3001 |
root_mp = root_mnt->mnt_mp; |
2d8f30380 [PATCH] sanitize ... |
3002 |
if (new.mnt->mnt_root != new.dentry) |
b12cea919 change the lockin... |
3003 |
goto out4; /* not a mountpoint */ |
676da58df vfs: spread struc... |
3004 |
if (!mnt_has_parent(new_mnt)) |
b12cea919 change the lockin... |
3005 |
goto out4; /* not attached */ |
4ac913785 Embed a struct pa... |
3006 |
/* make sure we can reach put_old from new_root */ |
84d17192d get rid of full-h... |
3007 |
if (!is_path_reachable(old_mnt, old.dentry, &new)) |
b12cea919 change the lockin... |
3008 |
goto out4; |
0d0826019 mnt: Prevent pivo... |
3009 3010 3011 |
/* make certain new is below the root */ if (!is_path_reachable(new_mnt, new.dentry, &root)) goto out4; |
84d17192d get rid of full-h... |
3012 |
root_mp->m_count++; /* pin it so it won't go away */ |
719ea2fbb new helpers: lock... |
3013 |
lock_mount_hash(); |
419148da6 vfs: spread struc... |
3014 3015 |
detach_mnt(new_mnt, &parent_path); detach_mnt(root_mnt, &root_parent); |
5ff9d8a65 vfs: Lock in plac... |
3016 3017 3018 3019 |
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... |
3020 |
/* mount old root on put_old */ |
84d17192d get rid of full-h... |
3021 |
attach_mnt(root_mnt, old_mnt, old_mp); |
4ac913785 Embed a struct pa... |
3022 |
/* mount new_root on / */ |
84d17192d get rid of full-h... |
3023 |
attach_mnt(new_mnt, real_mount(root_parent.mnt), root_mp); |
6b3286ed1 [PATCH] rename st... |
3024 |
touch_mnt_namespace(current->nsproxy->mnt_ns); |
4fed655c4 mnt: Clear mnt_ex... |
3025 3026 |
/* A moved mount should not expire automatically */ list_del_init(&new_mnt->mnt_expire); |
3895dbf89 mnt: Protect the ... |
3027 |
put_mountpoint(root_mp); |
719ea2fbb new helpers: lock... |
3028 |
unlock_mount_hash(); |
2d8f30380 [PATCH] sanitize ... |
3029 |
chroot_fs_refs(&root, &new); |
1da177e4c Linux-2.6.12-rc2 |
3030 |
error = 0; |
b12cea919 change the lockin... |
3031 |
out4: |
84d17192d get rid of full-h... |
3032 |
unlock_mount(old_mp); |
b12cea919 change the lockin... |
3033 3034 3035 3036 3037 |
if (!error) { path_put(&root_parent); path_put(&parent_path); } out3: |
8c3ee42e8 [PATCH] get rid o... |
3038 |
path_put(&root); |
b12cea919 change the lockin... |
3039 |
out2: |
2d8f30380 [PATCH] sanitize ... |
3040 |
path_put(&old); |
1da177e4c Linux-2.6.12-rc2 |
3041 |
out1: |
2d8f30380 [PATCH] sanitize ... |
3042 |
path_put(&new); |
1da177e4c Linux-2.6.12-rc2 |
3043 |
out0: |
1da177e4c Linux-2.6.12-rc2 |
3044 |
return error; |
1da177e4c Linux-2.6.12-rc2 |
3045 3046 3047 3048 3049 |
} static void __init init_mount_tree(void) { struct vfsmount *mnt; |
6b3286ed1 [PATCH] rename st... |
3050 |
struct mnt_namespace *ns; |
ac748a09f Make set_fs_{root... |
3051 |
struct path root; |
0c55cfc41 vfs: Allow unpriv... |
3052 |
struct file_system_type *type; |
1da177e4c Linux-2.6.12-rc2 |
3053 |
|
0c55cfc41 vfs: Allow unpriv... |
3054 3055 3056 3057 3058 |
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 |
3059 3060 |
if (IS_ERR(mnt)) panic("Can't create rootfs"); |
b3e19d924 fs: scale mntget/... |
3061 |
|
3b22edc57 VFS: Switch init_... |
3062 3063 |
ns = create_mnt_ns(mnt); if (IS_ERR(ns)) |
1da177e4c Linux-2.6.12-rc2 |
3064 |
panic("Can't allocate initial namespace"); |
6b3286ed1 [PATCH] rename st... |
3065 3066 3067 |
init_task.nsproxy->mnt_ns = ns; get_mnt_ns(ns); |
be08d6d26 switch mnt_namesp... |
3068 3069 |
root.mnt = mnt; root.dentry = mnt->mnt_root; |
da362b09e umount: Do not al... |
3070 |
mnt->mnt_flags |= MNT_LOCKED; |
ac748a09f Make set_fs_{root... |
3071 3072 3073 |
set_fs_pwd(current->fs, &root); set_fs_root(current->fs, &root); |
1da177e4c Linux-2.6.12-rc2 |
3074 |
} |
74bf17cff fs: remove the un... |
3075 |
void __init mnt_init(void) |
1da177e4c Linux-2.6.12-rc2 |
3076 |
{ |
15a67dd8c [PATCH] fs/namesp... |
3077 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
3078 |
|
7d6fec45a vfs: start hiding... |
3079 |
mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount), |
20c2df83d mm: Remove slab d... |
3080 |
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
3081 |
|
0818bf27c resizable namespa... |
3082 |
mount_hashtable = alloc_large_system_hash("Mount-cache", |
38129a13e switch mnt_hash t... |
3083 |
sizeof(struct hlist_head), |
0818bf27c resizable namespa... |
3084 |
mhash_entries, 19, |
3d375d785 mm: update caller... |
3085 |
HASH_ZERO, |
0818bf27c resizable namespa... |
3086 3087 3088 3089 |
&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... |
3090 |
HASH_ZERO, |
0818bf27c resizable namespa... |
3091 |
&mp_hash_shift, &mp_hash_mask, 0, 0); |
1da177e4c Linux-2.6.12-rc2 |
3092 |
|
84d17192d get rid of full-h... |
3093 |
if (!mount_hashtable || !mountpoint_hashtable) |
1da177e4c Linux-2.6.12-rc2 |
3094 3095 |
panic("Failed to allocate mount hash table "); |
4b93dc9b1 sysfs, kernfs: pr... |
3096 |
kernfs_init(); |
15a67dd8c [PATCH] fs/namesp... |
3097 3098 3099 3100 |
err = sysfs_init(); if (err) printk(KERN_WARNING "%s: sysfs_init error: %d ", |
8e24eea72 fs: replace remai... |
3101 |
__func__, err); |
00d266662 kobject: convert ... |
3102 3103 |
fs_kobj = kobject_create_and_add("fs", NULL); if (!fs_kobj) |
8e24eea72 fs: replace remai... |
3104 3105 |
printk(KERN_WARNING "%s: kobj create error ", __func__); |
1da177e4c Linux-2.6.12-rc2 |
3106 3107 3108 |
init_rootfs(); init_mount_tree(); } |
616511d03 VFS: Uninline the... |
3109 |
void put_mnt_ns(struct mnt_namespace *ns) |
1da177e4c Linux-2.6.12-rc2 |
3110 |
{ |
d498b25a4 get rid of useles... |
3111 |
if (!atomic_dec_and_test(&ns->count)) |
616511d03 VFS: Uninline the... |
3112 |
return; |
7b00ed6fe put_mnt_ns(): use... |
3113 |
drop_collected_mounts(&ns->root->mnt); |
771b13716 vfs: Add a user n... |
3114 |
free_mnt_ns(ns); |
1da177e4c Linux-2.6.12-rc2 |
3115 |
} |
9d412a43c vfs: split off vf... |
3116 3117 3118 |
struct vfsmount *kern_mount_data(struct file_system_type *type, void *data) { |
423e0ab08 VFS : mount lock ... |
3119 |
struct vfsmount *mnt; |
e462ec50c VFS: Differentiat... |
3120 |
mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, data); |
423e0ab08 VFS : mount lock ... |
3121 3122 3123 3124 3125 |
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_... |
3126 |
real_mount(mnt)->mnt_ns = MNT_NS_INTERNAL; |
423e0ab08 VFS : mount lock ... |
3127 3128 |
} return mnt; |
9d412a43c vfs: split off vf... |
3129 3130 |
} EXPORT_SYMBOL_GPL(kern_mount_data); |
423e0ab08 VFS : mount lock ... |
3131 3132 3133 3134 3135 |
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_... |
3136 |
real_mount(mnt)->mnt_ns = NULL; |
48a066e72 RCU'd vfsmounts |
3137 |
synchronize_rcu(); /* yecchhh... */ |
423e0ab08 VFS : mount lock ... |
3138 3139 3140 3141 |
mntput(mnt); } } EXPORT_SYMBOL(kern_unmount); |
02125a826 fix apparmor dere... |
3142 3143 3144 |
bool our_mnt(struct vfsmount *mnt) { |
143c8c91c vfs: mnt_ns moved... |
3145 |
return check_mnt(real_mount(mnt)); |
02125a826 fix apparmor dere... |
3146 |
} |
8823c079b vfs: Add setns su... |
3147 |
|
3151527ee userns: Don't al... |
3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 |
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_... |
3171 3172 |
static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new, int *new_mnt_flags) |
87a8ebd63 userns: Restrict ... |
3173 |
{ |
8c6cf9cc8 mnt: Modify fs_fu... |
3174 |
int new_flags = *new_mnt_flags; |
87a8ebd63 userns: Restrict ... |
3175 |
struct mount *mnt; |
e51db7353 userns: Better re... |
3176 |
bool visible = false; |
87a8ebd63 userns: Restrict ... |
3177 |
|
44bb4385c fs_is_visible onl... |
3178 |
down_read(&namespace_sem); |
87a8ebd63 userns: Restrict ... |
3179 |
list_for_each_entry(mnt, &ns->list, mnt_list) { |
e51db7353 userns: Better re... |
3180 |
struct mount *child; |
77b1a97d2 mnt: fs_fully_vis... |
3181 |
int mnt_flags; |
8654df4e2 mnt: Refactor fs_... |
3182 |
if (mnt->mnt.mnt_sb->s_type != new->mnt_sb->s_type) |
e51db7353 userns: Better re... |
3183 |
continue; |
7e96c1b0e mnt: Fix fs_fully... |
3184 3185 3186 3187 3188 |
/* 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... |
3189 |
/* A local view of the mount flags */ |
77b1a97d2 mnt: fs_fully_vis... |
3190 |
mnt_flags = mnt->mnt.mnt_flags; |
77b1a97d2 mnt: fs_fully_vis... |
3191 |
|
695e9df01 mnt: Account for ... |
3192 |
/* Don't miss readonly hidden in the superblock flags */ |
bc98a42c1 VFS: Convert sb->... |
3193 |
if (sb_rdonly(mnt->mnt.mnt_sb)) |
695e9df01 mnt: Account for ... |
3194 |
mnt_flags |= MNT_LOCK_READONLY; |
8c6cf9cc8 mnt: Modify fs_fu... |
3195 3196 3197 |
/* Verify the mount flags are equal to or more permissive * than the proposed new mount. */ |
77b1a97d2 mnt: fs_fully_vis... |
3198 |
if ((mnt_flags & MNT_LOCK_READONLY) && |
8c6cf9cc8 mnt: Modify fs_fu... |
3199 3200 |
!(new_flags & MNT_READONLY)) continue; |
77b1a97d2 mnt: fs_fully_vis... |
3201 3202 |
if ((mnt_flags & MNT_LOCK_ATIME) && ((mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK))) |
8c6cf9cc8 mnt: Modify fs_fu... |
3203 |
continue; |
ceeb0e5d3 vfs: Ignore unloc... |
3204 3205 3206 |
/* This mount is not fully visible if there are any * locked child mounts that cover anything except for * empty directories. |
e51db7353 userns: Better re... |
3207 3208 3209 |
*/ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { struct inode *inode = child->mnt_mountpoint->d_inode; |
ceeb0e5d3 vfs: Ignore unloc... |
3210 |
/* Only worry about locked mounts */ |
d71ed6c93 mnt: fs_fully_vis... |
3211 |
if (!(child->mnt.mnt_flags & MNT_LOCKED)) |
ceeb0e5d3 vfs: Ignore unloc... |
3212 |
continue; |
7236c85e1 mnt: Update fs_fu... |
3213 3214 |
/* Is the directory permanetly empty? */ if (!is_empty_dir_inode(inode)) |
e51db7353 userns: Better re... |
3215 |
goto next; |
87a8ebd63 userns: Restrict ... |
3216 |
} |
8c6cf9cc8 mnt: Modify fs_fu... |
3217 |
/* Preserve the locked attributes */ |
77b1a97d2 mnt: fs_fully_vis... |
3218 |
*new_mnt_flags |= mnt_flags & (MNT_LOCK_READONLY | \ |
77b1a97d2 mnt: fs_fully_vis... |
3219 |
MNT_LOCK_ATIME); |
e51db7353 userns: Better re... |
3220 3221 3222 |
visible = true; goto found; next: ; |
87a8ebd63 userns: Restrict ... |
3223 |
} |
e51db7353 userns: Better re... |
3224 |
found: |
44bb4385c fs_is_visible onl... |
3225 |
up_read(&namespace_sem); |
e51db7353 userns: Better re... |
3226 |
return visible; |
87a8ebd63 userns: Restrict ... |
3227 |
} |
8654df4e2 mnt: Refactor fs_... |
3228 3229 |
static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags) { |
a1935c173 mnt: Simplify mou... |
3230 |
const unsigned long required_iflags = SB_I_NOEXEC | SB_I_NODEV; |
8654df4e2 mnt: Refactor fs_... |
3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 |
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... |
3241 3242 3243 3244 3245 3246 |
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_... |
3247 3248 |
return !mnt_already_visible(ns, mnt, new_mnt_flags); } |
380cf5ba6 fs: Treat foreign... |
3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 |
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... |
3261 |
static struct ns_common *mntns_get(struct task_struct *task) |
8823c079b vfs: Add setns su... |
3262 |
{ |
58be28256 make mntns ->get(... |
3263 |
struct ns_common *ns = NULL; |
8823c079b vfs: Add setns su... |
3264 |
struct nsproxy *nsproxy; |
728dba3a3 namespaces: Use t... |
3265 3266 |
task_lock(task); nsproxy = task->nsproxy; |
8823c079b vfs: Add setns su... |
3267 |
if (nsproxy) { |
58be28256 make mntns ->get(... |
3268 3269 |
ns = &nsproxy->mnt_ns->ns; get_mnt_ns(to_mnt_ns(ns)); |
8823c079b vfs: Add setns su... |
3270 |
} |
728dba3a3 namespaces: Use t... |
3271 |
task_unlock(task); |
8823c079b vfs: Add setns su... |
3272 3273 3274 |
return ns; } |
64964528b make proc_ns_oper... |
3275 |
static void mntns_put(struct ns_common *ns) |
8823c079b vfs: Add setns su... |
3276 |
{ |
58be28256 make mntns ->get(... |
3277 |
put_mnt_ns(to_mnt_ns(ns)); |
8823c079b vfs: Add setns su... |
3278 |
} |
64964528b make proc_ns_oper... |
3279 |
static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns) |
8823c079b vfs: Add setns su... |
3280 3281 |
{ struct fs_struct *fs = current->fs; |
4f757f3cb make sure that mn... |
3282 |
struct mnt_namespace *mnt_ns = to_mnt_ns(ns), *old_mnt_ns; |
8823c079b vfs: Add setns su... |
3283 |
struct path root; |
4f757f3cb make sure that mn... |
3284 |
int err; |
8823c079b vfs: Add setns su... |
3285 |
|
0c55cfc41 vfs: Allow unpriv... |
3286 |
if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) || |
c7b96acf1 userns: Kill nso... |
3287 3288 |
!ns_capable(current_user_ns(), CAP_SYS_CHROOT) || !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) |
ae11e0f18 userns: fix retur... |
3289 |
return -EPERM; |
8823c079b vfs: Add setns su... |
3290 3291 3292 3293 3294 |
if (fs->users != 1) return -EINVAL; get_mnt_ns(mnt_ns); |
4f757f3cb make sure that mn... |
3295 |
old_mnt_ns = nsproxy->mnt_ns; |
8823c079b vfs: Add setns su... |
3296 3297 3298 |
nsproxy->mnt_ns = mnt_ns; /* Find the root */ |
4f757f3cb make sure that mn... |
3299 3300 3301 3302 3303 3304 3305 3306 |
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... |
3307 |
|
4068367c9 fs: don't forget ... |
3308 |
put_mnt_ns(old_mnt_ns); |
8823c079b vfs: Add setns su... |
3309 3310 3311 3312 3313 3314 3315 |
/* 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... |
3316 3317 3318 3319 |
static struct user_namespace *mntns_owner(struct ns_common *ns) { return to_mnt_ns(ns)->user_ns; } |
8823c079b vfs: Add setns su... |
3320 3321 3322 3323 3324 3325 |
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... |
3326 |
.owner = mntns_owner, |
8823c079b vfs: Add setns su... |
3327 |
}; |