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d0eb2f38b2
linux/fs/xfs
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Dave Chinner d0eb2f38b2 xfs: convert grant head manipulations to lockless algorithm 
The only thing that the grant lock remains to protect is the grant head
manipulations when adding or removing space from the log. These calculations
are already based on atomic variables, so we can already update them safely
without locks. However, the grant head manpulations require atomic multi-step
calculations to be executed, which the algorithms currently don't allow.

To make these multi-step calculations atomic, convert the algorithms to
compare-and-exchange loops on the atomic variables. That is, we sample the old
value, perform the calculation and use atomic64_cmpxchg() to attempt to update
the head with the new value. If the head has not changed since we sampled it,
it will succeed and we are done. Otherwise, we rerun the calculation again from
a new sample of the head.

This allows us to remove the grant lock from around all the grant head space
manipulations, and that effectively removes the grant lock from the log
completely. Hence we can remove the grant lock completely from the log at this
point.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:29:14 +11:00
..
linux-2.6 xfs: introduce new locks for the log grant ticket wait queues 2010-12-21 12:29:01 +11:00
quota xfs: use wait queues directly for the log wait queues 2010-12-21 12:09:01 +11:00
support xfs: drop dmapi hooks 2010-07-26 13:16:33 -05:00
Kconfig quota: Make QUOTACTL config be selected by its users 2010-10-05 12:16:37 +02:00
Makefile xfs: simplify log item descriptor tracking 2010-07-26 13:16:34 -05:00
xfs_acl.h
xfs_ag.h xfs: convert pag_ici_lock to a spin lock 2010-12-16 17:08:41 +11:00
xfs_alloc_btree.c xfs: remove the ->kill_root btree operation 2010-10-18 15:07:38 -05:00
xfs_alloc_btree.h
xfs_alloc.c xfs: factor duplicate code in xfs_alloc_ag_vextent_near into a helper 2010-12-16 16:06:15 -06:00
xfs_alloc.h xfs: do not use emums for flags used in tracing 2010-07-26 13:16:43 -05:00
xfs_arch.h
xfs_attr_leaf.c xfs: use KM_NOFS for allocations during attribute list operations 2010-12-23 11:57:37 +11:00
xfs_attr_leaf.h
xfs_attr_sf.h
xfs_attr.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_attr.h
xfs_bit.c
xfs_bit.h
xfs_bmap_btree.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_bmap_btree.h
xfs_bmap.c xfs: delayed alloc blocks beyond EOF are valid after writeback 2010-12-01 07:40:20 -06:00
xfs_bmap.h xfs: fix failed write truncation handling. 2010-12-01 07:40:19 -06:00
xfs_btree_trace.c
xfs_btree_trace.h
xfs_btree.c xfs: connect up buffer reclaim priority hooks 2010-12-02 16:31:13 +11:00
xfs_btree.h xfs: remove the ->kill_root btree operation 2010-10-18 15:07:38 -05:00
xfs_buf_item.c xfs: consume iodone callback items on buffers as they are processed 2010-12-03 17:00:52 +11:00
xfs_buf_item.h xfs: use struct list_head for the buf cancel table 2010-12-16 16:05:22 -06:00
xfs_da_btree.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_da_btree.h
xfs_dfrag.c xfs: delayed alloc blocks beyond EOF are valid after writeback 2010-12-01 07:40:20 -06:00
xfs_dfrag.h
xfs_dinode.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_dir2_block.c xfs: fix gcc 4.6 set but not read and unused statement warnings 2010-07-26 13:16:51 -05:00
xfs_dir2_block.h
xfs_dir2_data.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_dir2_data.h
xfs_dir2_leaf.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_dir2_leaf.h
xfs_dir2_node.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_dir2_node.h
xfs_dir2_sf.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_dir2_sf.h
xfs_dir2.c xfs: split xfs_itrace_entry 2010-07-26 13:16:44 -05:00
xfs_dir2.h
xfs_error.c xfs: only run xfs_error_test if error injection is active 2010-12-01 07:40:20 -06:00
xfs_error.h xfs: only run xfs_error_test if error injection is active 2010-12-01 07:40:20 -06:00
xfs_extfree_item.c xfs: Pull EFI/EFD handling out from under the AIL lock 2010-12-20 11:59:49 +11:00
xfs_extfree_item.h xfs: Pull EFI/EFD handling out from under the AIL lock 2010-12-20 11:59:49 +11:00
xfs_filestream.c xfs: tell lockdep about parent iolock usage in filestreams 2010-11-10 12:00:48 -06:00
xfs_filestream.h xfs: clean up filestreams helpers 2010-07-26 13:16:51 -05:00
xfs_fs.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_fsops.c xfs: dynamic speculative EOF preallocation 2011-01-04 11:35:03 +11:00
xfs_fsops.h xfs: dummy transactions should not dirty VFS state 2010-08-24 11:46:31 +10:00
xfs_ialloc_btree.c xfs: remove the ->kill_root btree operation 2010-10-18 15:07:38 -05:00
xfs_ialloc_btree.h
xfs_ialloc.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_ialloc.h
xfs_iget.c xfs: convert pag_ici_lock to a spin lock 2010-12-16 17:08:41 +11:00
xfs_inode_item.c xfs: remove all the inodes on a buffer from the AIL in bulk 2010-12-20 12:03:17 +11:00
xfs_inode_item.h xfs: simplify inode to transaction joining 2010-07-26 13:16:36 -05:00
xfs_inode.c xfs: connect up buffer reclaim priority hooks 2010-12-02 16:31:13 +11:00
xfs_inode.h xfs: don't truncate prealloc from frequently accessed inodes 2010-12-23 12:02:31 +11:00
xfs_inum.h
xfs_iomap.c xfs: dynamic speculative EOF preallocation 2011-01-04 11:35:03 +11:00
xfs_iomap.h xfs: kill xfs_iomap 2010-12-16 16:05:51 -06:00
xfs_itable.c xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_itable.h xfs: remove block number from inode lookup code 2010-06-24 11:35:17 +10:00
xfs_log_cil.c xfs: use wait queues directly for the log wait queues 2010-12-21 12:09:01 +11:00
xfs_log_priv.h xfs: convert grant head manipulations to lockless algorithm 2010-12-21 12:29:14 +11:00
xfs_log_recover.c xfs: convert l_tail_lsn to an atomic variable. 2010-12-21 12:28:39 +11:00
xfs_log_recover.h
xfs_log.c xfs: convert grant head manipulations to lockless algorithm 2010-12-21 12:29:14 +11:00
xfs_log.h xfs: remove the unused XFS_LOG_SLEEP and XFS_LOG_NOSLEEP flags 2010-07-26 13:16:38 -05:00
xfs_mount.c xfs: convert pag_ici_lock to a spin lock 2010-12-16 17:08:41 +11:00
xfs_mount.h xfs: dynamic speculative EOF preallocation 2011-01-04 11:35:03 +11:00
xfs_mru_cache.c
xfs_mru_cache.h
xfs_quota.h xfs: fix a few compiler warnings with CONFIG_XFS_QUOTA=n 2010-11-10 12:00:48 -06:00
xfs_rename.c xfs: log timestamp changes to the source inode in rename 2010-12-09 17:07:02 -06:00
xfs_rtalloc.c xfs: use unhashed buffers for size checks 2010-10-18 15:07:50 -05:00
xfs_rtalloc.h xfs: be more explicit if RT mount fails due to config 2010-05-28 14:58:24 -05:00
xfs_rw.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_rw.h
xfs_sb.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_trans_ail.c xfs: use AIL bulk delete function to implement single delete 2010-12-20 12:36:15 +11:00
xfs_trans_buf.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_trans_extfree.c xfs: Pull EFI/EFD handling out from under the AIL lock 2010-12-20 11:59:49 +11:00
xfs_trans_inode.c xfs: don't use vfs writeback for pure metadata modifications 2010-10-18 15:07:45 -05:00
xfs_trans_priv.h xfs: use AIL bulk delete function to implement single delete 2010-12-20 12:36:15 +11:00
xfs_trans_space.h
xfs_trans.c xfs: bulk AIL insertion during transaction commit 2010-12-20 12:02:19 +11:00
xfs_trans.h xfs: connect up buffer reclaim priority hooks 2010-12-02 16:31:13 +11:00
xfs_types.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_utils.c xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs_utils.h xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs_vnodeops.c xfs: don't truncate prealloc from frequently accessed inodes 2010-12-23 12:02:31 +11:00
xfs_vnodeops.h xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs.h