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authorAl Viro <viro@zeniv.linux.org.uk>2012-06-08 23:59:33 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-07-14 16:35:15 +0400
commitee3efa91e240f513898050ef305a49a653c8ed90 (patch)
treed6cf061b3636f3c5f9840c09f3ed6ccd625cff22 /fs/dcache.c
parente77fb7cef87856d9d35f2f4d617d0b97148ee7c2 (diff)
downloadlinux-ee3efa91e240f513898050ef305a49a653c8ed90.tar.xz
__d_unalias() should refuse to move mountpoints
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 015586f1ffc6..8086636bf796 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2387,14 +2387,13 @@ static struct dentry *__d_unalias(struct inode *inode,
struct dentry *dentry, struct dentry *alias)
{
struct mutex *m1 = NULL, *m2 = NULL;
- struct dentry *ret;
+ struct dentry *ret = ERR_PTR(-EBUSY);
/* If alias and dentry share a parent, then no extra locks required */
if (alias->d_parent == dentry->d_parent)
goto out_unalias;
/* See lock_rename() */
- ret = ERR_PTR(-EBUSY);
if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex))
goto out_err;
m1 = &dentry->d_sb->s_vfs_rename_mutex;
@@ -2402,8 +2401,10 @@ static struct dentry *__d_unalias(struct inode *inode,
goto out_err;
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
- __d_move(alias, dentry);
- ret = alias;
+ if (likely(!d_mountpoint(alias))) {
+ __d_move(alias, dentry);
+ ret = alias;
+ }
out_err:
spin_unlock(&inode->i_lock);
if (m2)