linux/fs/nfs
Chuck Lever 11476e9dec NFS: Fix an LOCK/OPEN race when unlinking an open file
At Connectathon 2016, we found that recent upstream Linux clients
would occasionally send a LOCK operation with a zero stateid. This
appeared to happen in close proximity to another thread returning
a delegation before unlinking the same file while it remained open.

Earlier, the client received a write delegation on this file and
returned the open stateid. Now, as it is getting ready to unlink the
file, it returns the write delegation. But there is still an open
file descriptor on that file, so the client must OPEN the file
again before it returns the delegation.

Since commit 24311f8841 ('NFSv4: Recovery of recalled read
delegations is broken'), nfs_open_delegation_recall() clears the
NFS_DELEGATED_STATE flag _before_ it sends the OPEN. This allows a
racing LOCK on the same inode to be put on the wire before the OPEN
operation has returned a valid open stateid.

To eliminate this race, serialize delegation return with the
acquisition of a file lock on the same file. Adopt the same approach
as is used in the unlock path.

This patch also eliminates a similar race seen when sending a LOCK
operation at the same time as returning a delegation on the same file.

Fixes: 24311f8841 ('NFSv4: Recovery of recalled read ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[Anna: Add sentence about LOCK / delegation race]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-09 09:05:40 -04:00
..
blocklayout mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
filelayout NFS: Save struct inode * inside nfs_commit_info to clarify usage of i_lock 2016-05-09 09:05:40 -04:00
flexfilelayout nfs: have flexfiles mirror keep creds for both ro and rw layouts 2016-05-09 09:05:40 -04:00
objlayout mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
cache_lib.c NFS: simplify and clean cache library 2013-02-15 10:43:36 -05:00
cache_lib.h NFS: simplify and clean cache library 2013-02-15 10:43:36 -05:00
callback_proc.c NFSv4.x: Fix NFS4ERR_RETRY_UNCACHED_REP in nfs4_callback_sequence 2016-02-01 12:06:24 -05:00
callback_xdr.c NFSv4.x: Allow multiple callbacks in flight 2016-01-25 09:36:21 -05:00
callback.c NFS: Enable client side NFSv4.1 backchannel to use other transports 2015-11-02 16:29:13 -05:00
callback.h NFSv4.x: Allow multiple callbacks in flight 2016-01-25 09:36:21 -05:00
client.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
delegation.c NFSv4: Don't use synchronous delegation recall in exception handling 2015-10-08 10:45:53 -04:00
delegation.h NFSv4: Recovery of recalled read delegations is broken 2015-09-20 22:34:16 -04:00
dir.c These changes contains a fix for overlayfs interacting with some 2016-04-07 17:22:20 -07:00
direct.c NFS: Save struct inode * inside nfs_commit_info to clarify usage of i_lock 2016-05-09 09:05:40 -04:00
dns_resolve.c NFS: Enabling v4.2 should not recompile nfsd and lockd 2013-11-19 16:20:40 -05:00
dns_resolve.h
file.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
fscache-index.c NFS: Fabricate fscache server index key correctly 2014-09-25 21:25:18 -04:00
fscache.c nfs: define nfs_inc_fscache_stats and using it as possible 2014-11-24 20:08:47 -05:00
fscache.h NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open() 2013-09-27 18:40:25 +01:00
getroot.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
inode.c These changes contains a fix for overlayfs interacting with some 2016-04-07 17:22:20 -07:00
internal.h mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
iostat.h nfs: define nfs_inc_fscache_stats and using it as possible 2014-11-24 20:08:47 -05:00
Kconfig kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
Makefile NFS: Rename idmap.c to nfs4idmap.c 2015-04-23 15:16:14 -04:00
mount_clnt.c NFS: Remove unneeded NFS_DEBUG checking before define NFSDBG_FACILITY 2015-10-21 15:49:23 -05:00
namespace.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
netns.h pnfs/blocklayout: serialize GETDEVICEINFO calls 2014-11-12 14:22:52 -05:00
nfs2super.c
nfs2xdr.c nfs: save server READ/WRITE/COMMIT status 2015-02-03 11:06:40 -08:00
nfs3_fs.h nfsv3: introduce nfs3_set_ds_client 2015-02-03 11:06:34 -08:00
nfs3acl.c posix acls: Remove duplicate xattr name definitions 2015-12-06 21:25:17 -05:00
nfs3client.c nfs: set hostname when creating nfsv3 ds connection 2015-02-03 11:06:38 -08:00
nfs3proc.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
nfs3super.c nfsv3: introduce nfs3_set_ds_client 2015-02-03 11:06:34 -08:00
nfs3xdr.c xprtrdma: Fix large NFS SYMLINK calls 2015-08-05 16:21:28 -04:00
nfs4_fs.h NFSv4: Refactor NFSv4 error handling 2015-10-08 10:45:51 -04:00
nfs4client.c nfs4: start callback_ident at idr 1 2015-11-23 21:59:42 -05:00
nfs4file.c These changes contains a fix for overlayfs interacting with some 2016-04-07 17:22:20 -07:00
nfs4getroot.c nfs: Remove invalid NFS_ATTR_FATTR_V4_REFERRAL checking in nfs4_get_rootfh 2015-07-01 11:31:22 -04:00
nfs4idmap.c KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
nfs4idmap.h NFS: Move nfs_idmap.h into fs/nfs/ 2015-04-23 15:16:14 -04:00
nfs4namespace.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
nfs4proc.c NFS: Fix an LOCK/OPEN race when unlinking an open file 2016-05-09 09:05:40 -04:00
nfs4renewd.c NFSv4.1: Fix an NFSv4.1 state renewal regression 2014-09-30 17:18:42 -04:00
nfs4session.c NFSv4.x: Allow multiple callbacks in flight 2016-01-25 09:36:21 -05:00
nfs4session.h NFSv4.x: Allow multiple callbacks in flight 2016-01-25 09:36:21 -05:00
nfs4state.c NFSv4: Don't try to reclaim unused state owners 2015-10-02 15:43:07 -04:00
nfs4super.c NFS: Move nfs_idmap.h into fs/nfs/ 2015-04-23 15:16:14 -04:00
nfs4sysctl.c nfs: do not initialise statics to 0 2015-12-28 09:57:15 -05:00
nfs4trace.c pNFS: Modify pnfs_update_layout tracepoints to use layout stateid 2015-12-28 09:57:14 -05:00
nfs4trace.h Merge branch 'bugfixes' 2016-01-07 18:45:36 -05:00
nfs4xdr.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
nfs42.h nfs42: add CLONE proc functions 2015-10-15 16:07:36 -04:00
nfs42proc.c nfs4: fix stateid handling for the NFS v4.2 operations 2016-02-17 11:38:07 -05:00
nfs42xdr.c nfs42: add CLONE xdr functions 2015-10-15 16:07:21 -04:00
nfs.h
nfsroot.c nfsroot: make nfsroot to accept the 1024 bytes long directory name 2015-10-21 15:49:19 -05:00
nfstrace.c NFSv4: Allow tracing of NFSv4 fsync calls 2015-03-27 12:39:34 -04:00
nfstrace.h NFS: Allow multiple commit requests in flight per file 2015-12-31 13:53:48 -05:00
pagelist.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
pnfs_dev.c NFSv4.1: Don't cache deviceids that have no notifications 2015-03-27 12:32:24 -04:00
pnfs_nfs.c NFS: Save struct inode * inside nfs_commit_info to clarify usage of i_lock 2016-05-09 09:05:40 -04:00
pnfs.c pnfs: set NFS_IOHDR_REDO in pnfs_read_resend_pnfs 2016-05-09 09:05:40 -04:00
pnfs.h pnfs: set NFS_IOHDR_REDO in pnfs_read_resend_pnfs 2016-05-09 09:05:40 -04:00
proc.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
read.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
super.c NFS: Remove the left global variable nfs_callback_tcpport 2015-10-21 15:49:22 -05:00
symlink.c switch ->get_link() to delayed_call, kill ->put_link() 2015-12-30 13:01:03 -05:00
sysctl.c nfs: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
unlink.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
write.c NFS: Save struct inode * inside nfs_commit_info to clarify usage of i_lock 2016-05-09 09:05:40 -04:00