diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7aa6ad1f014d..d763457b3cce 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1883,10 +1883,12 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans, return ret; } +#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len)) static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, u64 *discarded_bytes) { - int ret = 0; + int j, ret = 0; + u64 bytes_left, end; u64 aligned_start = ALIGN(start, 1 << 9); if (WARN_ON(start != aligned_start)) { @@ -1896,11 +1898,60 @@ static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, } *discarded_bytes = 0; - if (len) { - ret = blkdev_issue_discard(bdev, start >> 9, len >> 9, + + if (!len) + return 0; + + end = start + len; + bytes_left = len; + + /* Skip any superblocks on this device. */ + for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) { + u64 sb_start = btrfs_sb_offset(j); + u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE; + u64 size = sb_start - start; + + if (!in_range(sb_start, start, bytes_left) && + !in_range(sb_end, start, bytes_left) && + !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE)) + continue; + + /* + * Superblock spans beginning of range. Adjust start and + * try again. + */ + if (sb_start <= start) { + start += sb_end - start; + if (start > end) { + bytes_left = 0; + break; + } + bytes_left = end - start; + continue; + } + + if (size) { + ret = blkdev_issue_discard(bdev, start >> 9, size >> 9, + GFP_NOFS, 0); + if (!ret) + *discarded_bytes += size; + else if (ret != -EOPNOTSUPP) + return ret; + } + + start = sb_end; + if (start > end) { + bytes_left = 0; + break; + } + bytes_left = end - start; + } + + if (bytes_left) { + ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9, GFP_NOFS, 0); if (!ret) - *discarded_bytes = len; + *discarded_bytes += bytes_left; } return ret; }