xfs: simplify and remove xfs_ireclaim
xfs_ireclaim has to get and put te pag structure because it is only
called with the inode to reclaim. The one caller of this function
already has a reference on the pag and a pointer to is, so move the
radix tree delete to the caller and remove xfs_ireclaim completely.
This avoids a xfs_perag_get/put on every inode being reclaimed.
The overhead was noticed in a bug report at:
https://bugzilla.kernel.org/show_bug.cgi?id=16348
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index 66cefb2..dfcbd98 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -855,7 +855,36 @@
reclaim:
xfs_ifunlock(ip);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
- xfs_ireclaim(ip);
+
+ XFS_STATS_INC(xs_ig_reclaims);
+ /*
+ * Remove the inode from the per-AG radix tree.
+ *
+ * Because radix_tree_delete won't complain even if the item was never
+ * added to the tree assert that it's been there before to catch
+ * problems with the inode life time early on.
+ */
+ write_lock(&pag->pag_ici_lock);
+ if (!radix_tree_delete(&pag->pag_ici_root,
+ XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino)))
+ ASSERT(0);
+ write_unlock(&pag->pag_ici_lock);
+
+ /*
+ * Here we do an (almost) spurious inode lock in order to coordinate
+ * with inode cache radix tree lookups. This is because the lookup
+ * can reference the inodes in the cache without taking references.
+ *
+ * We make that OK here by ensuring that we wait until the inode is
+ * unlocked after the lookup before we go ahead and free it. We get
+ * both the ilock and the iolock because the code may need to drop the
+ * ilock one but will still hold the iolock.
+ */
+ xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+ xfs_qm_dqdetach(ip);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+
+ xfs_inode_free(ip);
return error;
}