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Diffstat (limited to 'fs/ext4/mmp.c')
-rw-r--r--fs/ext4/mmp.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index f99a1311e847..214461e42a05 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -7,7 +7,7 @@
#include "ext4.h"
/* Checksumming functions */
-static __u32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp)
+static __le32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
int offset = offsetof(struct mmp_struct, mmp_checksum);
@@ -44,13 +44,19 @@ static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
{
struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);
+ /*
+ * We protect against freezing so that we don't create dirty buffers
+ * on frozen filesystem.
+ */
+ sb_start_write(sb);
ext4_mmp_csum_set(sb, mmp);
mark_buffer_dirty(bh);
lock_buffer(bh);
bh->b_end_io = end_buffer_write_sync;
get_bh(bh);
- submit_bh(WRITE_SYNC, bh);
+ submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh);
wait_on_buffer(bh);
+ sb_end_write(sb);
if (unlikely(!buffer_uptodate(bh)))
return 1;
@@ -74,18 +80,20 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
* is not blocked in the elevator. */
if (!*bh)
*bh = sb_getblk(sb, mmp_block);
+ if (!*bh)
+ return -ENOMEM;
if (*bh) {
get_bh(*bh);
lock_buffer(*bh);
(*bh)->b_end_io = end_buffer_read_sync;
- submit_bh(READ_SYNC, *bh);
+ submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh);
wait_on_buffer(*bh);
if (!buffer_uptodate(*bh)) {
brelse(*bh);
*bh = NULL;
}
}
- if (!*bh) {
+ if (unlikely(!*bh)) {
ext4_warning(sb, "Error while reading MMP block %llu",
mmp_block);
return -EIO;