Btrfs: Leaf reference cache update

This changes the reference cache to make a single cache per root
instead of one cache per transaction, and to key by the byte number
of the disk block instead of the keys inside.

This makes it much less likely to have cache misses if a snapshot
or something has an extra reference on a higher node or a leaf while
the first transaction that added the leaf into the cache is dropping.

Some throttling is added to functions that free blocks heavily so they
wait for old transactions to drop.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index cf9534b79aba..4f977ea5497e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2482,7 +2482,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
         btrfs_update_inode_block_group(trans, dir);
 out_unlock:
         nr = trans->blocks_used;
-        btrfs_end_transaction_throttle(trans, root);
+        btrfs_end_transaction(trans, root);
 fail:
         if (drop_inode) {
                 inode_dec_link_count(inode);
@@ -2535,7 +2535,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                 drop_inode = 1;
 
         nr = trans->blocks_used;
-        btrfs_end_transaction_throttle(trans, root);
+        btrfs_end_transaction(trans, root);
 fail:
         if (drop_inode) {
                 inode_dec_link_count(inode);
@@ -2609,7 +2609,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
 out_fail:
         nr = trans->blocks_used;
-        btrfs_end_transaction_throttle(trans, root);
+        btrfs_end_transaction(trans, root);
 
 out_unlock:
         if (drop_on_err)
@@ -3548,7 +3548,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 
 out_unlock:
         nr = trans->blocks_used;
-        btrfs_end_transaction_throttle(trans, root);
+        btrfs_end_transaction(trans, root);
 out_fail:
         if (drop_inode) {
                 inode_dec_link_count(inode);