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| author | Miklos Szeredi <miklos@szeredi.hu> | 2005-07-07 17:57:26 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-07-07 18:23:51 -0700 |
| commit | ed42c879b7b1463aa7a15fdbbeb2b1914d60be8a (patch) | |
| tree | 191f9386a8288e06d7d0e914434aea2f9a56e1ca /fs/namespace.c | |
| parent | 24ca2af1e7cff55e71e9f86c61ddc56e894b8b40 (diff) | |
| download | lwn-ed42c879b7b1463aa7a15fdbbeb2b1914d60be8a.tar.gz lwn-ed42c879b7b1463aa7a15fdbbeb2b1914d60be8a.zip | |
[PATCH] namespace.c: fix expiring of detached mount
This patch fixes a bug noticed by Al Viro:
However, we still have a problem here - just what would
happen if vfsmount is detached while we were grabbing namespace
semaphore? Refcount alone is not useful here - we might be held by
whoever had detached the vfsmount. IOW, we should check that it's
still attached (i.e. that mnt->mnt_parent != mnt). If it's not -
just leave it alone, do mntput() and let whoever holds it deal with
the sucker. No need to put it back on lists.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index d82cf18a1a94..2b4635e43ae8 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -830,6 +830,15 @@ static void expire_mount(struct vfsmount *mnt, struct list_head *mounts) spin_lock(&vfsmount_lock); /* + * Check if mount is still attached, if not, let whoever holds it deal + * with the sucker + */ + if (mnt->mnt_parent == mnt) { + spin_unlock(&vfsmount_lock); + return; + } + + /* * Check that it is still dead: the count should now be 2 - as * contributed by the vfsmount parent and the mntget above */ |