diff options
| -rw-r--r-- | fs/btrfs/file.c | 34 |
1 files changed, 12 insertions, 22 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 4373da7bcc0d..7c5e3d406574 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1591,8 +1591,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, size_t write_bytes = min(iov_iter_count(i), nrptrs * (size_t)PAGE_SIZE - offset); - size_t num_pages = DIV_ROUND_UP(write_bytes + offset, - PAGE_SIZE); + size_t num_pages; size_t reserve_bytes; size_t dirty_pages; size_t copied; @@ -1600,8 +1599,6 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, size_t num_sectors; int extents_locked; - WARN_ON(num_pages > nrptrs); - /* * Fault pages before locking them in prepare_pages * to avoid recursive lock @@ -1613,35 +1610,28 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, only_release_metadata = false; sector_offset = pos & (fs_info->sectorsize - 1); - reserve_bytes = round_up(write_bytes + sector_offset, - fs_info->sectorsize); extent_changeset_release(data_reserved); ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, pos, write_bytes); if (ret < 0) { + /* + * If we don't have to COW at the offset, reserve + * metadata only. write_bytes may get smaller than + * requested here. + */ if (btrfs_check_nocow_lock(BTRFS_I(inode), pos, - &write_bytes) > 0) { - /* - * For nodata cow case, no need to reserve - * data space. - */ + &write_bytes) > 0) only_release_metadata = true; - /* - * our prealloc extent may be smaller than - * write_bytes, so scale down. - */ - num_pages = DIV_ROUND_UP(write_bytes + offset, - PAGE_SIZE); - reserve_bytes = round_up(write_bytes + - sector_offset, - fs_info->sectorsize); - } else { + else break; - } } + num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE); + WARN_ON(num_pages > nrptrs); + reserve_bytes = round_up(write_bytes + sector_offset, + fs_info->sectorsize); WARN_ON(reserve_bytes == 0); ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), reserve_bytes); |