linux/fs/nfsd
David Woodhouse 2f9092e102 Fix i_mutex vs. readdir handling in nfsd
Commit 14f7dd63 ("Copy XFS readdir hack into nfsd code") introduced a
bug to generic code which had been extant for a long time in the XFS
version -- it started to call through into lookup_one_len() and hence
into the file systems' ->lookup() methods without i_mutex held on the
directory.

This patch fixes it by locking the directory's i_mutex again before
calling the filldir functions. The original deadlocks which commit
14f7dd63 was designed to avoid are still avoided, because they were due
to fs-internal locking, not i_mutex.

While we're at it, fix the return type of nfsd_buffered_readdir() which
should be a __be32 not an int -- it's an NFS errno, not a Linux errno.
And return nfserrno(-ENOMEM) when allocation fails, not just -ENOMEM.
Sparse would have caught that, if it wasn't so busy bitching about
__cold__.

Commit 05f4f678 ("nfsd4: don't do lookup within readdir in recovery
code") introduced a similar problem with calling lookup_one_len()
without i_mutex, which this patch also addresses. To fix that, it was
necessary to fix the called functions so that they expect i_mutex to be
held; that part was done by J. Bruce Fields.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Umm-I-can-live-with-that-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Tested-by: J. Bruce Fields <bfields@citi.umich.edu>
LKML-Reference: <8036.1237474444@jrobl>
Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:01:16 -04:00
..
auth.c nfsd: fix cred leak on every rpc 2009-01-27 17:26:59 -05:00
auth.h nfsd: minor fs/nfsd/auth.h cleanup 2008-02-01 16:42:05 -05:00
export.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2008-10-23 10:22:40 -07:00
Kconfig nfsd : Define NFSD only when FILE_LOCKING is enabled 2009-03-18 17:30:48 -04:00
lockd.c nfsd: common grace period control 2008-10-03 16:19:02 -04:00
Makefile knfsd: trivial makefile cleanup 2007-05-09 12:30:54 -07:00
nfs2acl.c nfsd: rename MAY_ flags 2008-06-23 13:02:50 -04:00
nfs3acl.c nfsd: rename MAY_ flags 2008-06-23 13:02:50 -04:00
nfs3proc.c Short write in nfsd becomes a full write to the client 2009-03-18 17:38:40 -04:00
nfs3xdr.c Use struct path in struct svc_export 2008-02-14 21:17:08 -08:00
nfs4acl.c nfsd: fix buffer overrun decoding NFSv4 acl 2008-09-01 14:24:24 -04:00
nfs4callback.c nfsd4: move rpc_client setup to a separate function 2009-03-18 17:38:39 -04:00
nfs4idmap.c nfsd: fix sparse warnings 2008-04-23 16:13:39 -04:00
nfs4proc.c nfsd41: CREATE_EXCLUSIVE4_1 2009-04-03 17:41:23 -07:00
nfs4recover.c Fix i_mutex vs. readdir handling in nfsd 2009-04-20 23:01:16 -04:00
nfs4state.c nfsd41: add OPEN4_SHARE_ACCESS_WANT nfs4_stateid bmap 2009-04-03 17:41:21 -07:00
nfs4xdr.c nfsd41: CREATE_EXCLUSIVE4_1 2009-04-03 17:41:23 -07:00
nfscache.c nfsd: fail module init on reply cache init failure 2008-02-01 16:42:04 -05:00
nfsctl.c Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linux 2009-04-06 13:25:56 -07:00
nfsfh.c NFSD: FIDs need to take precedence over UUIDs 2009-01-07 17:23:07 -05:00
nfsproc.c Short write in nfsd becomes a full write to the client 2009-03-18 17:38:40 -04:00
nfssvc.c Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linux 2009-04-06 13:25:56 -07:00
nfsxdr.c Use struct path in struct svc_export 2008-02-14 21:17:08 -08:00
stats.c
vfs.c Fix i_mutex vs. readdir handling in nfsd 2009-04-20 23:01:16 -04:00