diff options
| -rw-r--r-- | fs/btrfs/disk-io.c | 43 |
1 files changed, 29 insertions, 14 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index b7ddc77fa568..0d50d49d990a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2020,6 +2020,17 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev) return latest; } +/* + * this should be called twice, once with wait == 0 and + * once with wait == 1. When wait == 0 is done, all the buffer heads + * we write are pinned. + * + * They are released when wait == 1 is done. + * max_mirrors must be the same for both runs, and it indicates how + * many supers on this one device should be written. + * + * max_mirrors == 0 means to write them all. + */ static int write_dev_supers(struct btrfs_device *device, struct btrfs_super_block *sb, int do_barriers, int wait, int max_mirrors) @@ -2055,12 +2066,16 @@ static int write_dev_supers(struct btrfs_device *device, bh = __find_get_block(device->bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE); BUG_ON(!bh); - brelse(bh); wait_on_buffer(bh); - if (buffer_uptodate(bh)) { - brelse(bh); - continue; - } + if (!buffer_uptodate(bh)) + errors++; + + /* drop our reference */ + brelse(bh); + + /* drop the reference from the wait == 0 run */ + brelse(bh); + continue; } else { btrfs_set_super_bytenr(sb, bytenr); @@ -2071,12 +2086,18 @@ static int write_dev_supers(struct btrfs_device *device, BTRFS_CSUM_SIZE); btrfs_csum_final(crc, sb->csum); + /* + * one reference for us, and we leave it for the + * caller + */ bh = __getblk(device->bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE); memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE); - set_buffer_uptodate(bh); + /* one reference for submit_bh */ get_bh(bh); + + set_buffer_uptodate(bh); lock_buffer(bh); bh->b_end_io = btrfs_end_buffer_write_sync; } @@ -2088,6 +2109,7 @@ static int write_dev_supers(struct btrfs_device *device, device->name); set_buffer_uptodate(bh); device->barriers = 0; + /* one reference for submit_bh */ get_bh(bh); lock_buffer(bh); ret = submit_bh(WRITE_SYNC, bh); @@ -2096,15 +2118,8 @@ static int write_dev_supers(struct btrfs_device *device, ret = submit_bh(WRITE_SYNC, bh); } - if (!ret && wait) { - wait_on_buffer(bh); - if (!buffer_uptodate(bh)) - errors++; - } else if (ret) { + if (ret) errors++; - } - if (wait) - brelse(bh); } return errors < i ? 0 : -1; } |