[PATCH] namei fixes (13/19)
In open_namei() exit_dput: we have mntput() done in the wrong order -
if nd->mnt != path.mnt we end up doing
mntput(nd->mnt);
nd->mnt = path.mnt;
dput(nd->dentry);
mntput(nd->mnt);
which drops nd->dentry too late. Fixed by having path.mnt go first.
That allows to switch O_NOFOLLOW under if (__follow_mount(...)) back
to exit_dput, while we are at it.
Fix for early-mntput() race + equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/namei.c b/fs/namei.c
index 37fcf94..5153f57 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1501,11 +1501,8 @@
if (__follow_mount(&path)) {
error = -ELOOP;
- if (flag & O_NOFOLLOW) {
- dput(path.dentry);
- mntput(path.mnt);
- goto exit;
- }
+ if (flag & O_NOFOLLOW)
+ goto exit_dput;
}
error = -ENOENT;
if (!path.dentry->d_inode)
@@ -1530,8 +1527,7 @@
exit_dput:
dput(path.dentry);
if (nd->mnt != path.mnt)
- mntput(nd->mnt);
- nd->mnt = path.mnt;
+ mntput(path.mnt);
exit:
path_release(nd);
return error;