aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChris Mason <chris.mason@oracle.com>2012-01-31 20:19:02 -0500
committerChris Mason <chris.mason@oracle.com>2012-03-28 20:34:10 -0400
commit7ca4be45a0255ac8f08c05491c6add2dd87dd4f8 (patch)
treeaca39ca7f1d210138733cb3be54c408a2acf302b
parent3c4bb26b213e618473e486776483a5bad15ba6da (diff)
downloadlinux-linaro-stable-7ca4be45a0255ac8f08c05491c6add2dd87dd4f8.tar.gz
Btrfs: don't use crc items bigger than 4KB
With the big metadata blocks, we can have crc items that are much bigger than a page. There are a few places that we try to kmalloc memory to hold the items during a split. Items bigger than 4KB don't really have a huge benefit in efficiency, but they do trigger larger order allocations. This commits changes the csums to make sure they stay under 4KB. This is not a format change, just a #define to limit huge items. Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/file-item.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index a14dbca5974e..cab0ffb5ef3b 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -25,10 +25,12 @@
#include "transaction.h"
#include "print-tree.h"
-#define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+#define __MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
sizeof(struct btrfs_item) * 2) / \
size) - 1))
+#define MAX_CSUM_ITEMS(r, size) (min(__MAX_CSUM_ITEMS(r, size), PAGE_CACHE_SIZE))
+
#define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
sizeof(struct btrfs_ordered_sum)) / \
sizeof(struct btrfs_sector_sum) * \