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| author | Al Viro <viro@zeniv.linux.org.uk> | 2007-06-07 12:20:32 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2007-10-21 02:37:25 -0400 |
| commit | 8aec08094570562bc305df33b088926d983c3540 (patch) | |
| tree | 399f4590f81428d1f72d754d336da13c449120f9 | |
| parent | 5a190ae69766da9a34bf31200c5cea4c0667cf94 (diff) | |
| download | linux-8aec08094570562bc305df33b088926d983c3540.tar.bz2 | |
[PATCH] new helpers - collect_mounts() and release_collected_mounts()
Get a snapshot of a subtree, creating private clones of vfsmounts
for all its components and release such snapshot resp.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namespace.c | 22 | ||||
| -rw-r--r-- | fs/pnode.h | 1 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
3 files changed, 24 insertions, 1 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 860752998fb3..06083885b21e 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -246,7 +246,7 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, list_add(&mnt->mnt_slave, &old->mnt_slave_list); mnt->mnt_master = old; CLEAR_MNT_SHARED(mnt); - } else { + } else if (!(flag & CL_PRIVATE)) { if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old)) list_add(&mnt->mnt_share, &old->mnt_share); if (IS_MNT_SLAVE(old)) @@ -746,6 +746,26 @@ Enomem: return NULL; } +struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry) +{ + struct vfsmount *tree; + down_read(&namespace_sem); + tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE); + up_read(&namespace_sem); + return tree; +} + +void drop_collected_mounts(struct vfsmount *mnt) +{ + LIST_HEAD(umount_list); + down_read(&namespace_sem); + spin_lock(&vfsmount_lock); + umount_tree(mnt, 0, &umount_list); + spin_unlock(&vfsmount_lock); + up_read(&namespace_sem); + release_mounts(&umount_list); +} + /* * @source_mnt : mount tree to be attached * @nd : place the mount tree @source_mnt is attached diff --git a/fs/pnode.h b/fs/pnode.h index d45bd8ec36bf..f249be2fee7a 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -22,6 +22,7 @@ #define CL_COPY_ALL 0x04 #define CL_MAKE_SHARED 0x08 #define CL_PROPAGATION 0x10 +#define CL_PRIVATE 0x20 static inline void set_mnt_shared(struct vfsmount *mnt) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 1bcce660cf03..50078bb30a1c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1470,6 +1470,8 @@ extern long do_mount(char *, char *, char *, unsigned long, void *); extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int); extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *, struct vfsmount *); +extern struct vfsmount *collect_mounts(struct vfsmount *, struct dentry *); +extern void drop_collected_mounts(struct vfsmount *); extern int vfs_statfs(struct dentry *, struct kstatfs *); |