xfs: use per-filesystem I/O completion workqueues

The new concurrency managed workqueues are cheap enough that we can create
per-filesystem instead of global workqueues.  This allows us to remove the
trylock or defer scheme on the ilock, which is not helpful once we have
outstanding log reservations until finishing a size update.

Also allow the default concurrency on this workqueues so that I/O completions
blocking on the ilock for one inode do not block process for another inode.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index c082e44dad2d..9eba73887829 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -211,6 +211,9 @@ typedef struct xfs_mount {
         struct shrinker         m_inode_shrink; /* inode reclaim shrinker */
         int64_t                 m_low_space[XFS_LOWSP_MAX];
                                                 /* low free space thresholds */
+
+        struct workqueue_struct *m_data_workqueue;
+        struct workqueue_struct *m_unwritten_workqueue;
 } xfs_mount_t;
 
 /*