diff options
| -rw-r--r-- | fs/btrfs/direct-io.c | 126 |
1 files changed, 65 insertions, 61 deletions
diff --git a/fs/btrfs/direct-io.c b/fs/btrfs/direct-io.c index b2add124cc89..3e227292b0ac 100644 --- a/fs/btrfs/direct-io.c +++ b/fs/btrfs/direct-io.c @@ -621,74 +621,78 @@ static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, const bool write = !!(flags & IOMAP_WRITE); int ret = 0; - if (!write && (iomap->type == IOMAP_HOLE)) { - /* If reading from a hole, unlock and return */ - btrfs_unlock_dio_extent(&BTRFS_I(inode)->io_tree, pos, - pos + length - 1, NULL); + if (!write) { + /* + * Hole read, nothing is submitted, thus we have to unlock + * the whole range. + */ + if (iomap->type == IOMAP_HOLE) { + btrfs_unlock_dio_extent(&BTRFS_I(inode)->io_tree, pos, + pos + length - 1, NULL); + return 0; + } + /* + * Short read, needs to unlock the remaining range, and + * return -ENOTBLK so we can later fault in the pages and retry. + */ + if (written < length) { + btrfs_unlock_dio_extent(&BTRFS_I(inode)->io_tree, pos + written, + pos + length - 1, NULL); + return -ENOTBLK; + } + /* The full range is submitted, endio will do the unlock. */ return 0; } if (written < length) { - pos += written; - length -= written; - if (write) { - /* - * Got a short write and have updated the isize, need to - * revert the isize change. - * - * Normally we need to update isize with extent lock hold, - * but we're safe due to the following factors: - * - * - Only a single writer can be enlarging isize - * Enlarging isize will take the exclusive inode lock. - * - * - Buffered readers need to wait for the OE we're holding - * Buffered readers will lock extent and wait for OE - * of the folio range, and since page cache is invalidated - * the OE wait can not be skipped. - * - * So here we are safe to revert the isize before - * finishing the OE, and no reader of the remaining range - * can see the enlarged size. - * - * TODO: Extend the DIO_LOCKED lifespan for direct writes, - * and only enlarge isize after a successful write. - */ - if (dio_data->updated_isize) { - u64 new_isize; - - if (written == 0) - new_isize = dio_data->old_isize; - else - new_isize = max(dio_data->old_isize, pos); - i_size_write(inode, new_isize); - dio_data->updated_isize = false; - } - /* - * We have a short write, if there is any range - * that is submitted properly, that part will have - * its own OE split from the original one. - * - * So for the OE at dio_data->ordered, it's the part - * that is not submitted, and should be marked - * as fully truncated. - */ - btrfs_mark_ordered_extent_truncated(dio_data->ordered, 0); - btrfs_finish_ordered_extent(dio_data->ordered, - pos, length, true); - } else { - btrfs_unlock_dio_extent(&BTRFS_I(inode)->io_tree, pos, - pos + length - 1, NULL); + /* + * Got a short write and have updated the i_size, need to revert + * the i_size change. + * + * Normally we need to update i_size with extent lock held, but + * we're safe due to the following factors: + * + * - Only a single writer can be enlarging i_size + * Enlarging i_size will take the exclusive inode lock. + * + * - Buffered readers need to wait for the OE we're holding + * Buffered readers will lock extent and wait for OE + * of the folio range, and since page cache is invalidated + * the OE wait cannot be skipped. + * + * So here we are safe to revert the isize before finishing the + * OE, and no reader of the remaining range can see the enlarged + * size. + * + * TODO: Extend the DIO_LOCKED lifespan for direct writes, + * and only enlarge isize after a successful write. + */ + if (dio_data->updated_isize) { + u64 new_isize; + + if (written == 0) + new_isize = dio_data->old_isize; + else + new_isize = max(dio_data->old_isize, pos + written); + i_size_write(inode, new_isize); + dio_data->updated_isize = false; } + /* + * We have a short write, if there is any range that is submitted + * properly, that part will have its own OE split from the + * original one. + * + * So for the OE at dio_data->ordered, it's the part that is not + * submitted, and should be marked as fully truncated. + */ + btrfs_mark_ordered_extent_truncated(dio_data->ordered, 0); + btrfs_finish_ordered_extent(dio_data->ordered, + pos + written, length - written, true); ret = -ENOTBLK; } - if (write) { - btrfs_put_ordered_extent(dio_data->ordered); - dio_data->ordered = NULL; - } - - if (write) - extent_changeset_free(dio_data->data_reserved); + btrfs_put_ordered_extent(dio_data->ordered); + dio_data->ordered = NULL; + extent_changeset_free(dio_data->data_reserved); return ret; } |