diff options
| author | David Howells <dhowells@redhat.com> | 2024-04-04 18:05:19 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2024-04-19 23:37:47 +0300 |
| commit | dad80c6bff770d25f67ec25fe011730e4a463008 (patch) | |
| tree | 5fc5557eddfaeecaa96f2bf41a8954f38fc2d66b /fs/smb/client/cifsglob.h | |
| parent | 0bbac3facb5d6cc0171c45c9873a2dc96bea9680 (diff) | |
| download | linux-dad80c6bff770d25f67ec25fe011730e4a463008.tar.xz | |
cifs: Fix reacquisition of volume cookie on still-live connection
During mount, cifs_mount_get_tcon() gets a tcon resource connection record
and then attaches an fscache volume cookie to it. However, it does this
irrespective of whether or not the tcon returned from cifs_get_tcon() is a
new record or one that's already in use. This leads to a warning about a
volume cookie collision and a leaked volume cookie because tcon->fscache
gets reset.
Fix this be adding a mutex and a "we've already tried this" flag and only
doing it once for the lifetime of the tcon.
[!] Note: Looking at cifs_mount_get_tcon(), a more general solution may
actually be required. Reacquiring the volume cookie isn't the only thing
that function does: it also partially reinitialises the tcon record without
any locking - which may cause live filesystem ops already using the tcon
through a previous mount to malfunction.
This can be reproduced simply by something like:
mount //example.com/test /xfstest.test -o user=shares,pass=xxx,fsc
mount //example.com/test /mnt -o user=shares,pass=xxx,fsc
Fixes: 70431bfd825d ("cifs: Support fscache indexing rewrite")
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb/client/cifsglob.h')
| -rw-r--r-- | fs/smb/client/cifsglob.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index d6669ce4ae87..fc09d1c0ee07 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -1276,7 +1276,9 @@ struct cifs_tcon { __u32 max_cached_dirs; #ifdef CONFIG_CIFS_FSCACHE u64 resource_id; /* server resource id */ + bool fscache_acquired; /* T if we've tried acquiring a cookie */ struct fscache_volume *fscache; /* cookie for share */ + struct mutex fscache_lock; /* Prevent regetting a cookie */ #endif struct list_head pending_opens; /* list of incomplete opens */ struct cached_fids *cfids; |