summaryrefslogtreecommitdiff
path: root/fs/btrfs/compression.c
diff options
context:
space:
mode:
authorChris Mason <chris.mason@oracle.com>2009-09-03 00:24:52 +0400
committerChris Mason <chris.mason@oracle.com>2009-09-11 21:31:05 +0400
commit890871be854b5f5e43e7ba2475f706209906cc24 (patch)
tree9d087adf7a28bb910992d07d93ea2a992e394110 /fs/btrfs/compression.c
parent57fd5a5ff8b48b99e90b22fc143082aba755c6c0 (diff)
downloadlinux-890871be854b5f5e43e7ba2475f706209906cc24.tar.xz
Btrfs: switch extent_map to a rw lock
There are two main users of the extent_map tree. The first is regular file inodes, where it is evenly spread between readers and writers. The second is the chunk allocation tree, which maps blocks from logical addresses to phyiscal ones, and it is 99.99% reads. The mapping tree is a point of lock contention during heavy IO workloads, so this commit switches things to a rw lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/compression.c')
-rw-r--r--fs/btrfs/compression.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index de1e2fd32080..78451a58f209 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -507,10 +507,10 @@ static noinline int add_ra_bio_pages(struct inode *inode,
*/
set_page_extent_mapped(page);
lock_extent(tree, last_offset, end, GFP_NOFS);
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, last_offset,
PAGE_CACHE_SIZE);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
if (!em || last_offset < em->start ||
(last_offset + PAGE_CACHE_SIZE > extent_map_end(em)) ||
@@ -594,11 +594,11 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
em_tree = &BTRFS_I(inode)->extent_tree;
/* we need the actual starting offset of this extent in the file */
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree,
page_offset(bio->bi_io_vec->bv_page),
PAGE_CACHE_SIZE);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
compressed_len = em->block_len;
cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);