From patchwork Wed Dec 5 09:17:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Carlos Maiolino X-Patchwork-Id: 10713401 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 691FE18B8 for ; Wed, 5 Dec 2018 09:17:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 59D2D2CD0E for ; Wed, 5 Dec 2018 09:17:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E25E2CD16; Wed, 5 Dec 2018 09:17:41 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B1E6A2CD12 for ; Wed, 5 Dec 2018 09:17:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726924AbeLEJRk (ORCPT ); Wed, 5 Dec 2018 04:17:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36822 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726351AbeLEJRk (ORCPT ); Wed, 5 Dec 2018 04:17:40 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 475695F722; Wed, 5 Dec 2018 09:17:39 +0000 (UTC) Received: from hades.usersys.redhat.com (unknown [10.43.17.43]) by smtp.corp.redhat.com (Postfix) with ESMTP id 08BED5D965; Wed, 5 Dec 2018 09:17:37 +0000 (UTC) From: Carlos Maiolino To: linux-fsdevel@vger.kernel.org Cc: hch@lst.de, adilger@dilger.ca, sandeen@redhat.com, david@fromorbit.com Subject: [PATCH 01/10] fs: Enable bmap() function to properly return errors Date: Wed, 5 Dec 2018 10:17:19 +0100 Message-Id: <20181205091728.29903-2-cmaiolino@redhat.com> In-Reply-To: <20181205091728.29903-1-cmaiolino@redhat.com> References: <20181205091728.29903-1-cmaiolino@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 05 Dec 2018 09:17:39 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP By now, bmap() will either return the physical block number related to the requested file offset or 0 in case of error or the requested offset maps into a hole. This patch makes the needed changes to enable bmap() to proper return errors, using the return value as an error return, and now, a pointer must be passed to bmap() to be filled with the mapped physical block. It will change the behavior of bmap() on return: - negative value in case of error - zero on success or map fell into a hole In case of a hole, the *block will be zero too Since this is a prep patch, by now, the only error return is -EINVAL if ->bmap doesn't exist. Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino --- drivers/md/md-bitmap.c | 16 ++++++++++------ fs/inode.c | 30 +++++++++++++++++------------- fs/jbd2/journal.c | 22 +++++++++++++++------- include/linux/fs.h | 2 +- mm/page_io.c | 11 +++++++---- 5 files changed, 50 insertions(+), 31 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index 1cd4f991792c..0668b2dd290e 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -363,7 +363,7 @@ static int read_page(struct file *file, unsigned long index, int ret = 0; struct inode *inode = file_inode(file); struct buffer_head *bh; - sector_t block; + sector_t block, blk_cur; pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE, (unsigned long long)index << PAGE_SHIFT); @@ -374,17 +374,21 @@ static int read_page(struct file *file, unsigned long index, goto out; } attach_page_buffers(page, bh); - block = index << (PAGE_SHIFT - inode->i_blkbits); + blk_cur = index << (PAGE_SHIFT - inode->i_blkbits); while (bh) { + block = blk_cur; + if (count == 0) bh->b_blocknr = 0; else { - bh->b_blocknr = bmap(inode, block); - if (bh->b_blocknr == 0) { - /* Cannot use this file! */ + ret = bmap(inode, &block); + if (ret || !block) { ret = -EINVAL; + bh->b_blocknr = 0; goto out; } + + bh->b_blocknr = block; bh->b_bdev = inode->i_sb->s_bdev; if (count < (1<i_blkbits)) count = 0; @@ -398,7 +402,7 @@ static int read_page(struct file *file, unsigned long index, set_buffer_mapped(bh); submit_bh(REQ_OP_READ, 0, bh); } - block++; + blk_cur++; bh = bh->b_this_page; } page->index = index; diff --git a/fs/inode.c b/fs/inode.c index 0cd47fe0dbe5..db681d310465 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1580,21 +1580,25 @@ EXPORT_SYMBOL(iput); /** * bmap - find a block number in a file - * @inode: inode of file - * @block: block to find - * - * Returns the block number on the device holding the inode that - * is the disk block number for the block of the file requested. - * That is, asked for block 4 of inode 1 the function will return the - * disk block relative to the disk start that holds that block of the - * file. + * @inode: inode owning the block number being requested + * @*block: pointer containing the block to find + * + * Replaces the value in *block with the block number on the device holding + * corresponding to the requested block number in the file. + * That is, asked for block 4 of inode 1 the function will replace the + * 4 in *block, with disk block relative to the disk start that holds that + * block of the file. + * + * Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a + * hole, returns 0 and *block is also set to 0. */ -sector_t bmap(struct inode *inode, sector_t block) +int bmap(struct inode *inode, sector_t *block) { - sector_t res = 0; - if (inode->i_mapping->a_ops->bmap) - res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); - return res; + if (!inode->i_mapping->a_ops->bmap) + return -EINVAL; + + *block = inode->i_mapping->a_ops->bmap(inode->i_mapping, *block); + return 0; } EXPORT_SYMBOL(bmap); diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 8ef6b6daaa7a..7acaf6f55404 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -814,18 +814,23 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, { int err = 0; unsigned long long ret; + sector_t block = 0; if (journal->j_inode) { - ret = bmap(journal->j_inode, blocknr); - if (ret) - *retp = ret; - else { + block = blocknr; + ret = bmap(journal->j_inode, &block); + + if (ret || !block) { printk(KERN_ALERT "%s: journal block not found " "at offset %lu on %s\n", __func__, blocknr, journal->j_devname); err = -EIO; __journal_abort_soft(journal, err); + + } else { + *retp = block; } + } else { *retp = blocknr; /* +journal->j_blk_offset */ } @@ -1251,11 +1256,14 @@ journal_t *jbd2_journal_init_dev(struct block_device *bdev, journal_t *jbd2_journal_init_inode(struct inode *inode) { journal_t *journal; + sector_t blocknr; char *p; - unsigned long long blocknr; + int err = 0; + + blocknr = 0; + err = bmap(inode, &blocknr); - blocknr = bmap(inode, 0); - if (!blocknr) { + if (err || !blocknr) { pr_err("%s: Cannot locate journal superblock\n", __func__); return NULL; diff --git a/include/linux/fs.h b/include/linux/fs.h index 5f7f67bd33a5..71dac6e00e27 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2811,7 +2811,7 @@ static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count) extern void emergency_sync(void); extern void emergency_remount(void); #ifdef CONFIG_BLOCK -extern sector_t bmap(struct inode *, sector_t); +extern int bmap(struct inode *, sector_t *); #endif extern int notify_change(struct dentry *, struct iattr *, struct inode **); extern int inode_permission(struct inode *, int); diff --git a/mm/page_io.c b/mm/page_io.c index 57572ff46016..b52e3e2ec13c 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -177,8 +177,9 @@ int generic_swapfile_activate(struct swap_info_struct *sis, cond_resched(); - first_block = bmap(inode, probe_block); - if (first_block == 0) + first_block = probe_block; + ret = bmap(inode, &first_block); + if (ret || !first_block) goto bad_bmap; /* @@ -193,9 +194,11 @@ int generic_swapfile_activate(struct swap_info_struct *sis, block_in_page++) { sector_t block; - block = bmap(inode, probe_block + block_in_page); - if (block == 0) + block = probe_block + block_in_page; + ret = bmap(inode, &block); + if (ret || !block) goto bad_bmap; + if (block != first_block + block_in_page) { /* Discontiguity */ probe_block++;