From patchwork Mon Apr 3 18:53:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 746631 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vxh9M46RDz9s7n for ; Tue, 4 Apr 2017 04:54:31 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752631AbdDCSyW (ORCPT ); Mon, 3 Apr 2017 14:54:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:46017 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752358AbdDCSx4 (ORCPT ); Mon, 3 Apr 2017 14:53:56 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id CA821ACCA; Mon, 3 Apr 2017 18:53:54 +0000 (UTC) From: Goldwyn Rodrigues To: linux-fsdevel@vger.kernel.org Cc: jack@suse.com, hch@infradead.org, linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, sagi@grimberg.me, avi@scylladb.com, axboe@kernel.dk, linux-api@vger.kernel.org, willy@infradead.org, tom.leiming@gmail.com, Goldwyn Rodrigues Subject: [PATCH 8/8] nowait aio: btrfs Date: Mon, 3 Apr 2017 13:53:07 -0500 Message-Id: <20170403185307.6243-9-rgoldwyn@suse.de> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20170403185307.6243-1-rgoldwyn@suse.de> References: <20170403185307.6243-1-rgoldwyn@suse.de> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Goldwyn Rodrigues Return EAGAIN if any of the following checks fail + i_rwsem is not lockable + NODATACOW or PREALLOC is not set + Cannot nocow at the desired location + Writing beyond end of file which is not allocated --- fs/btrfs/file.c | 25 ++++++++++++++++++++----- fs/btrfs/inode.c | 3 +++ fs/btrfs/super.c | 2 +- 3 files changed, 24 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 520cb72..a870e5d 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1823,12 +1823,29 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, ssize_t num_written = 0; bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host); ssize_t err; - loff_t pos; - size_t count; + loff_t pos = iocb->ki_pos; + size_t count = iov_iter_count(from); loff_t oldsize; int clean_page = 0; - inode_lock(inode); + if ((iocb->ki_flags & IOCB_NOWAIT) && + (iocb->ki_flags & IOCB_DIRECT)) { + /* Don't sleep on inode rwsem */ + if (!inode_trylock(inode)) + return -EAGAIN; + /* + * We will allocate space in case nodatacow is not set, + * so bail + */ + if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | + BTRFS_INODE_PREALLOC)) || + check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) { + inode_unlock(inode); + return -EAGAIN; + } + } else + inode_lock(inode); + err = generic_write_checks(iocb, from); if (err <= 0) { inode_unlock(inode); @@ -1862,8 +1879,6 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, */ update_time_for_write(inode); - pos = iocb->ki_pos; - count = iov_iter_count(from); start_pos = round_down(pos, fs_info->sectorsize); oldsize = i_size_read(inode); if (start_pos > oldsize) { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a18510b..d91b21a 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8627,6 +8627,9 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) dio_data.overwrite = 1; inode_unlock(inode); relock = true; + } else if (iocb->ki_flags & IOCB_NOWAIT) { + ret = -EAGAIN; + goto out; } ret = btrfs_delalloc_reserve_space(inode, offset, count); if (ret) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index da687dc..5e60659 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2175,7 +2175,7 @@ static struct file_system_type btrfs_fs_type = { .name = "btrfs", .mount = btrfs_mount, .kill_sb = btrfs_kill_super, - .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, + .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_NOWAIT, }; MODULE_ALIAS_FS("btrfs");