/*
* Write the MMP block using WRITE_SYNC to try to get the block on-disk
* faster.
*/
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);
#ifdef FEATURE_STORAGE_META_LOG
if( bh && bh->b_bdev && bh->b_bdev->bd_disk)
set_metadata_rw_status(bh->b_bdev->bd_disk->first_minor, WAIT_WRITE_CNT);
#endif
submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh);
wait_on_buffer(bh);
sb_end_write(sb);
if (unlikely(!buffer_uptodate(bh)))
return 1;
return 0;
}
/*
* Write the MMP block using WRITE_SYNC to try to get the block on-disk
* faster.
*/
static int write_mmp_block(struct buffer_head *bh)
{
mark_buffer_dirty(bh);
lock_buffer(bh);
bh->b_end_io = end_buffer_write_sync;
get_bh(bh);
#ifdef FEATURE_STORAGE_META_LOG
set_metadata_rw_status(bh->b_bdev->bd_disk->first_minor, WAIT_WRITE_CNT);
#endif
submit_bh(WRITE_SYNC, bh);
wait_on_buffer(bh);
if (unlikely(!buffer_uptodate(bh)))
return 1;
return 0;
}
/*
* Read the MMP block. It _must_ be read from disk and hence we clear the
* uptodate flag on the buffer.
*/
static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
ext4_fsblk_t mmp_block)
{
struct mmp_struct *mmp;
if (*bh)
clear_buffer_uptodate(*bh);
/* This would be sb_bread(sb, mmp_block), except we need to be sure
* that the MD RAID device cache has been bypassed, and that the read
* 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;
#ifdef FEATURE_STORAGE_META_LOG
if( (*bh) && (*bh)->b_bdev && (*bh)->b_bdev->bd_disk)
set_metadata_rw_status((*bh)->b_bdev->bd_disk->first_minor, WAIT_READ_CNT);
#endif
submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh);
wait_on_buffer(*bh);
if (!buffer_uptodate(*bh)) {
brelse(*bh);
*bh = NULL;
}
}
if (unlikely(!*bh)) {
ext4_warning(sb, "Error while reading MMP block %llu",
mmp_block);
return -EIO;
}
mmp = (struct mmp_struct *)((*bh)->b_data);
if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC ||
!ext4_mmp_csum_verify(sb, mmp))
return -EINVAL;
return 0;
}
