Btrfs: do not async metadata csumming in certain situations

[linux-2.6-block.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index dcaf55695e6f1139f24d5e702b222d62e25d9d41..aa02eab8c40b42f08a22e75d87aec247a32f43cf 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -46,6 +46,10 @@
 #include "check-integrity.h"
 #include "rcu-string.h"
 
+#ifdef CONFIG_X86
+#include <asm/cpufeature.h>
+#endif
+
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
 static void free_fs_root(struct btrfs_root *root);
@@ -859,10 +863,22 @@ static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
        return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 }
 
+static int check_async_write(struct inode *inode, unsigned long bio_flags)
+{
+       if (bio_flags & EXTENT_BIO_TREE_LOG)
+               return 0;
+#ifdef CONFIG_X86
+       if (cpu_has_xmm4_2)
+               return 0;
+#endif
+       return 1;
+}
+
 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
                                 int mirror_num, unsigned long bio_flags,
                                 u64 bio_offset)
 {
+       int async = check_async_write(inode, bio_flags);
        int ret;
 
        if (!(rw & REQ_WRITE)) {
@@ -877,6 +893,12 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
                        return ret;
                return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
                                     mirror_num, 0);
+       } else if (!async) {
+               ret = btree_csum_one_bio(bio);
+               if (ret)
+                       return ret;
+               return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
+                                    mirror_num, 0);
        }
 
        /*