linux/fs/nfsd
Jeff Layton 1c8c601a8c locks: protect most of the file_lock handling with i_lock
Having a global lock that protects all of this code is a clear
scalability problem. Instead of doing that, move most of the code to be
protected by the i_lock instead. The exceptions are the global lists
that the ->fl_link sits on, and the ->fl_block list.

->fl_link is what connects these structures to the
global lists, so we must ensure that we hold those locks when iterating
over or updating these lists.

Furthermore, sound deadlock detection requires that we hold the
blocked_list state steady while checking for loops. We also must ensure
that the search and update to the list are atomic.

For the checking and insertion side of the blocked_list, push the
acquisition of the global lock into __posix_lock_file and ensure that
checking and update of the  blocked_list is done without dropping the
lock in between.

On the removal side, when waking up blocked lock waiters, take the
global lock before walking the blocked list and dequeue the waiters from
the global list prior to removal from the fl_block list.

With this, deadlock detection should be race free while we minimize
excessive file_lock_lock thrashing.

Finally, in order to avoid a lock inversion problem when handling
/proc/locks output we must ensure that manipulations of the fl_block
list are also protected by the file_lock_lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:42 +04:00
..
Kconfig fs/nfsd: remove depends on CONFIG_EXPERIMENTAL 2013-01-21 14:39:05 -08:00
Makefile NFSD: Added fault injection 2011-11-07 21:10:47 -05:00
acl.h nfsd: Remove declaration of nonexistent nfs4_acl_permisison 2013-02-13 06:15:35 -08:00
auth.c nfsd: Properly compare and initialize kuids and kgids 2013-02-13 06:16:09 -08:00
auth.h nfsd: Remove nfsd_luid, nfsd_lgid, nfsd_ruid and nfsd_rgid 2013-02-13 06:15:51 -08:00
cache.h nfsd: add new reply_cache_stats file in nfsdfs 2013-04-03 11:47:24 -04:00
current_stateid.h nfsd41: use current stateid by value 2012-02-15 11:20:45 -05:00
export.c Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
fault_inject.c Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
idmap.h nfsd: Convert idmap to use kuids and kgids 2013-02-13 06:15:49 -08:00
lockd.c nfsd: Remove deprecated nfsctl system call and related code. 2011-07-15 18:58:42 -04:00
netns.h nfsd4: make del_recall_lru per-network-namespace 2013-04-04 13:25:16 -04:00
nfs2acl.c nfsd: handle vfs_getattr errors in acl protocol 2013-02-26 02:46:09 -05:00
nfs3acl.c nfsd4: cleanup: replace rq_resused count by rq_next_page pointer 2012-12-17 22:00:16 -05:00
nfs3proc.c switch vfs_getattr() to struct path 2013-02-26 02:46:08 -05:00
nfs3xdr.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
nfs4acl.c nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion 2013-02-13 06:16:06 -08:00
nfs4callback.c nfsd4: check backchannel attributes on create_session 2013-04-09 16:53:56 -04:00
nfs4idmap.c Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
nfs4proc.c nfsd4: don't allow owner override on 4.1 CLAIM_FH opens 2013-05-03 16:36:14 -04:00
nfs4recover.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
nfs4state.c locks: protect most of the file_lock handling with i_lock 2013-06-29 12:57:42 +04:00
nfs4xdr.c NFSD: SECINFO doesn't handle unsupported pseudoflavors correctly 2013-04-30 19:18:21 -04:00
nfscache.c nfsd: make symbol nfsd_reply_cache_shrinker static 2013-04-30 18:19:34 -04:00
nfsctl.c Merge branch 'for-3.10' of git://linux-nfs.org/~bfields/linux 2013-05-03 10:59:39 -07:00
nfsd.h fs/nfsd: change type of max_delegations, nfsd_drc_max_mem and nfsd_drc_mem_used 2013-02-23 17:50:22 -08:00
nfsfh.c exportfs: add FILEID_INVALID to indicate invalid fid_type 2012-11-07 19:22:30 -05:00
nfsfh.h fs: propagate umode_t, misc bits 2012-01-03 22:55:10 -05:00
nfsproc.c switch vfs_getattr() to struct path 2013-02-26 02:46:08 -05:00
nfssvc.c Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
nfsxdr.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
state.h nfsd4: implement SEQ4_STATUS_RECALLABLE_STATE_REVOKED 2013-04-16 10:59:30 -04:00
stats.c SUNRPC: register service stats /proc entries in passed network namespace context 2012-01-31 19:28:18 -05:00
vfs.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
vfs.h switch vfs_getattr() to struct path 2013-02-26 02:46:08 -05:00
xdr.h nfsd: handle vfs_getattr errors in acl protocol 2013-02-26 02:46:09 -05:00
xdr3.h nfsd: handle vfs_getattr errors in acl protocol 2013-02-26 02:46:09 -05:00
xdr4.h nfsd4: cleanup handling of nfsv4.0 closed stateid's 2013-04-08 09:55:32 -04:00
xdr4cb.h nfsd4: check backchannel attributes on create_session 2013-04-09 16:53:56 -04:00