linux/fs/nfs
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
..
blocklayout make blkdev_put() return void 2013-05-07 02:16:31 -04:00
objlayout treewide: Fix typo in printks 2013-04-12 15:21:36 +02:00
cache_lib.c
cache_lib.h
callback_proc.c NFSv4.1 Fix a pNFS session draining deadlock 2013-05-20 14:20:14 -04:00
callback_xdr.c NFSv4.1 Fix a pNFS session draining deadlock 2013-05-20 14:20:14 -04:00
callback.c nfs: allow the v4.1 callback thread to freeze 2013-04-05 17:03:52 -04:00
callback.h
client.c NFSv4.1: Set the RPC_CLNT_CREATE_INFINITE_SLOTS flag for NFSv4.1 transports 2013-04-14 12:59:28 -04:00
delegation.c locks: protect most of the file_lock handling with i_lock 2013-06-29 12:57:42 +04:00
delegation.h NFSv4: Fix CB_RECALL_ANY to only return delegations that are not in use 2013-04-05 17:03:57 -04:00
dir.c [readdir] convert nfs 2013-06-29 12:56:40 +04:00
direct.c
dns_resolve.c
dns_resolve.h
file.c NFS: Ensure that NFS file unlock waits for readahead to complete 2013-04-08 22:12:42 -04:00
fscache-index.c
fscache.c
fscache.h
getroot.c
idmap.c NFSv4: Fix the string length returned by the idmapper 2013-03-20 16:45:16 -04:00
inode.c NFS: Add functionality to allow waiting on all outstanding reads to complete 2013-04-08 22:12:33 -04:00
internal.h NFS: Add functionality to allow waiting on all outstanding reads to complete 2013-04-08 22:12:33 -04:00
iostat.h
Kconfig
Makefile
mount_clnt.c
namespace.c
netns.h
nfs2super.c
nfs2xdr.c
nfs3acl.c
nfs3client.c
nfs3proc.c
nfs3super.c
nfs3xdr.c
nfs4_fs.h NFSv4.1: Ensure that we free the lock stateid on the server 2013-05-06 17:24:27 -04:00
nfs4client.c NFS: Fix SETCLIENTID fallback if GSS is not available 2013-05-23 18:50:40 -04:00
nfs4file.c
nfs4filelayout.c NFSv4: The stateid must remain the same for replayed RPC calls 2013-03-25 12:04:10 -04:00
nfs4filelayout.h NFS4.1 Fix data server connection race 2013-05-08 17:19:32 -04:00
nfs4filelayoutdev.c NFS4.1 Fix data server connection race 2013-05-08 17:19:32 -04:00
nfs4getroot.c
nfs4namespace.c SUNRPC: Introduce rpcauth_get_pseudoflavor() 2013-03-29 15:43:07 -04:00
nfs4proc.c NFSv4: Fix a thinko in nfs4_try_open_cached 2013-05-29 16:03:23 -04:00
nfs4renewd.c
nfs4session.c NFSv4.1 Fix a pNFS session draining deadlock 2013-05-20 14:20:14 -04:00
nfs4session.h NFSv4.1 Fix a pNFS session draining deadlock 2013-05-20 14:20:14 -04:00
nfs4state.c locks: protect most of the file_lock handling with i_lock 2013-06-29 12:57:42 +04:00
nfs4super.c NFS: Use server-recommended security flavor by default (NFSv3) 2013-04-04 17:01:01 -04:00
nfs4sysctl.c
nfs4xdr.c NFSv4: Convert nfs41_free_stateid to use an asynchronous RPC call 2013-05-06 17:24:22 -04:00
nfs.h
nfsroot.c
pagelist.c NFS: Add functionality to allow waiting on all outstanding reads to complete 2013-04-08 22:12:33 -04:00
pnfs_dev.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
pnfs.c NFSv4: Fail I/O if the state recovery fails irrevocably 2013-03-25 12:04:10 -04:00
pnfs.h NFSv4.1: Add a helper pnfs_commit_and_return_layout 2013-03-21 10:31:21 -04:00
proc.c
read.c NFS: Don't accept more reads/writes if the open context recovery failed 2013-03-25 12:04:10 -04:00
super.c NFS: Fix security flavor negotiation with legacy binary mounts 2013-05-30 16:31:34 -04:00
symlink.c
sysctl.c
unlink.c
write.c NFS: Don't accept more reads/writes if the open context recovery failed 2013-03-25 12:04:10 -04:00