Btrfs: cache ordered extent when completing io
When finishing io we run btrfs_dec_test_ordered_pending, and then immediately
run btrfs_lookup_ordered_extent, but btrfs_dec_test_ordered_pending does that
already, so we're searching twice when we don't have to. This patch lets us
pass a btrfs_ordered_extent in to btrfs_dec_test_ordered_pending so if we do
complete io on that ordered extent we can just use the one we found then instead
of having to do another btrfs_lookup_ordered_extent. This made my fio job with
the other patch go from 24 mb/s to 29 mb/s.
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 50ce884..1824dda 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1698,11 +1698,10 @@
int compressed = 0;
int ret;
- ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
+ ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
+ end - start + 1);
if (!ret)
return 0;
-
- ordered_extent = btrfs_lookup_ordered_extent(inode, start);
BUG_ON(!ordered_extent);
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index d56f732..a8ffecd 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -232,11 +232,12 @@
* to make sure this function only returns 1 once for a given ordered extent.
*/
int btrfs_dec_test_ordered_pending(struct inode *inode,
+ struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
- struct btrfs_ordered_extent *entry;
+ struct btrfs_ordered_extent *entry = NULL;
int ret;
tree = &BTRFS_I(inode)->ordered_tree;
@@ -264,6 +265,10 @@
else
ret = 1;
out:
+ if (!ret && cached && entry) {
+ *cached = entry;
+ atomic_inc(&entry->refs);
+ }
spin_unlock(&tree->lock);
return ret == 0;
}
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index bfbcebb..c82f76a 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -137,7 +137,8 @@
int btrfs_remove_ordered_extent(struct inode *inode,
struct btrfs_ordered_extent *entry);
int btrfs_dec_test_ordered_pending(struct inode *inode,
- u64 file_offset, u64 io_size);
+ struct btrfs_ordered_extent **cached,
+ u64 file_offset, u64 io_size);
int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
u64 start, u64 len, u64 disk_len, int tyep);
int btrfs_add_ordered_sum(struct inode *inode,