From patchwork Tue Nov 1 21:06:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9408119 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 99B8E60585 for ; Tue, 1 Nov 2016 21:22:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8D64629A50 for ; Tue, 1 Nov 2016 21:22:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 824E929A9C; Tue, 1 Nov 2016 21:22:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2FCCA29A50 for ; Tue, 1 Nov 2016 21:22:17 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 1F42A81D36; Tue, 1 Nov 2016 14:22:13 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id BCD2081CC1 for ; Tue, 1 Nov 2016 14:22:11 -0700 (PDT) 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 59FB6AD70; Tue, 1 Nov 2016 21:22:11 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 479091E0F93; Tue, 1 Nov 2016 22:06:27 +0100 (CET) From: Jan Kara To: linux-ext4@vger.kernel.org Subject: [PATCH 04/11] ext4: Convert DAX reads to iomap infrastructure Date: Tue, 1 Nov 2016 22:06:14 +0100 Message-Id: <1478034381-19037-5-git-send-email-jack@suse.cz> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1478034381-19037-1-git-send-email-jack@suse.cz> References: <1478034381-19037-1-git-send-email-jack@suse.cz> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fsdevel@vger.kernel.org, Dave Chinner , Jan Kara , Ted Tso , linux-nvdimm@lists.01.org MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Implement basic iomap_begin function that handles reading and use it for DAX reads. Signed-off-by: Jan Kara --- fs/ext4/ext4.h | 2 ++ fs/ext4/file.c | 40 +++++++++++++++++++++++++++++++++++++++- fs/ext4/inode.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 95 insertions(+), 1 deletion(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 282a51b07c57..098b39910001 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -3271,6 +3271,8 @@ static inline bool ext4_aligned_io(struct inode *inode, loff_t off, loff_t len) return IS_ALIGNED(off, blksize) && IS_ALIGNED(len, blksize); } +extern struct iomap_ops ext4_iomap_ops; + #endif /* __KERNEL__ */ #define EFSBADCRC EBADMSG /* Bad CRC detected */ diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 55f8b922b76d..28ebc2418dc2 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -31,6 +31,44 @@ #include "xattr.h" #include "acl.h" +#ifdef CONFIG_FS_DAX +static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + ssize_t ret; + + inode_lock_shared(inode); + /* + * Recheck under inode lock - at this point we are sure it cannot + * change anymore + */ + if (!IS_DAX(inode)) { + inode_unlock_shared(inode); + /* Fallback to buffered IO in case we cannot support DAX */ + return generic_file_read_iter(iocb, to); + } + ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops); + inode_unlock_shared(inode); + + file_accessed(iocb->ki_filp); + return ret; +} +#endif + +static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + +#ifdef CONFIG_FS_DAX + if (IS_DAX(inode)) + return ext4_dax_read_iter(iocb, to); +#endif + return generic_file_read_iter(iocb, to); +} + /* * Called when an inode is released. Note that this is different * from ext4_file_open: open gets called at every open, but release @@ -691,7 +729,7 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence) const struct file_operations ext4_file_operations = { .llseek = ext4_llseek, - .read_iter = generic_file_read_iter, + .read_iter = ext4_file_read_iter, .write_iter = ext4_file_write_iter, .unlocked_ioctl = ext4_ioctl, #ifdef CONFIG_COMPAT diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 4cbd1b24c237..cc10145ea98b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "ext4_jbd2.h" #include "xattr.h" @@ -3305,6 +3306,59 @@ int ext4_dax_get_block(struct inode *inode, sector_t iblock, clear_buffer_new(bh_result); return 0; } + +static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned flags, struct iomap *iomap) +{ + unsigned int blkbits = inode->i_blkbits; + unsigned long first_block = offset >> blkbits; + unsigned long last_block = (offset + length - 1) >> blkbits; + struct ext4_map_blocks map; + int ret; + + if (flags & IOMAP_WRITE) + return -EIO; + + if (WARN_ON_ONCE(ext4_has_inline_data(inode))) + return -ERANGE; + + map.m_lblk = first_block; + map.m_len = last_block - first_block + 1; + + ret = ext4_map_blocks(NULL, inode, &map, 0); + if (ret < 0) + return ret; + + iomap->flags = 0; + iomap->bdev = inode->i_sb->s_bdev; + iomap->offset = first_block << blkbits; + + if (ret == 0) { + iomap->type = IOMAP_HOLE; + iomap->blkno = IOMAP_NULL_BLOCK; + iomap->length = (u64)map.m_len << blkbits; + } else { + if (map.m_flags & EXT4_MAP_MAPPED) { + iomap->type = IOMAP_MAPPED; + } else if (map.m_flags & EXT4_MAP_UNWRITTEN) { + iomap->type = IOMAP_UNWRITTEN; + } else { + WARN_ON_ONCE(1); + return -EIO; + } + iomap->blkno = (sector_t)map.m_pblk << (blkbits - 9); + iomap->length = (u64)map.m_len << blkbits; + } + + if (map.m_flags & EXT4_MAP_NEW) + iomap->flags |= IOMAP_F_NEW; + return 0; +} + +struct iomap_ops ext4_iomap_ops = { + .iomap_begin = ext4_iomap_begin, +}; + #else /* Just define empty function, it will never get called. */ int ext4_dax_get_block(struct inode *inode, sector_t iblock,