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| author | Al Viro <viro@zeniv.linux.org.uk> | 2008-03-22 23:19:49 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-04-22 07:11:09 +0400 |
| commit | 1a60a280778ff90270fc7390d9ec102f713a5a29 (patch) | |
| tree | 988cb5b1446ecc298aee4771b0768d777165226c | |
| parent | 6d59e7f582ef1c1988542d0fc3b36d0087b757ce (diff) | |
| download | linux-1a60a280778ff90270fc7390d9ec102f713a5a29.tar.xz | |
[PATCH] lock exclusively in collect_mounts() and drop_collected_mounts()
Taking namespace_sem shared there isn't worth the trouble, especially with
vfsmount ID allocation about to be added. That way we know that umount_tree(),
copy_tree() and clone_mnt() are _always_ serialized by namespace_sem.
umount_tree() still needs vfsmount_lock (it manipulates hash chains, among
other things), but that's a separate story.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namespace.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 678f7ce060f2..af2fb3707d0a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1091,20 +1091,20 @@ Enomem: struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry) { struct vfsmount *tree; - down_read(&namespace_sem); + down_write(&namespace_sem); tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE); - up_read(&namespace_sem); + up_write(&namespace_sem); return tree; } void drop_collected_mounts(struct vfsmount *mnt) { LIST_HEAD(umount_list); - down_read(&namespace_sem); + down_write(&namespace_sem); spin_lock(&vfsmount_lock); umount_tree(mnt, 0, &umount_list); spin_unlock(&vfsmount_lock); - up_read(&namespace_sem); + up_write(&namespace_sem); release_mounts(&umount_list); } |