From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FC01CCA47B for ; Sun, 5 Jun 2022 14:38:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345063AbiFEOig (ORCPT ); Sun, 5 Jun 2022 10:38:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345052AbiFEOie (ORCPT ); Sun, 5 Jun 2022 10:38:34 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D8E611811; Sun, 5 Jun 2022 07:38:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=280Wtqh+IaR+ohRn0i2SNeEIg3cG1n1gmfJkVF27ebM=; b=BiAVdWspfWXj/AOzHUemf++t4T k1JAoS9zARQrO/zZSlmWWy3MLu+WzBYbanzB0z33evw4UEHInxjyWB/0/H424pmzV7+Z7SOvY1Bvc T/fLowpBzOmFSBSPYGG7l12f8YZsEMUR3SZ54eoLftKyecse+eFeWK9YD8eusKDhGlc0FPPFNKXYl gRW9RKhejDW8Su8HkhlYNk/U8MV7KHmJJtEnXF1+ckWljZc1XUmRnf0/5yER5VNGWLVLUsLM9RnD8 nw2MTagIu62BjLnoS3qRYXdQJcuywYSqAVHdXfsqSptfQ01mqF0/F6EI6RhOtC14ibBz1eQiX+1OE lgsmvymA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nxrOU-009mNu-SR; Sun, 05 Jun 2022 14:38:18 +0000 From: "Matthew Wilcox (Oracle)" To: Jan Kara Cc: "Matthew Wilcox (Oracle)" , tytso@mit.edu, Andreas Dilger , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 3/3] ext4: Use generic_quota_read() Date: Sun, 5 Jun 2022 15:38:15 +0100 Message-Id: <20220605143815.2330891-4-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220605143815.2330891-1-willy@infradead.org> References: <20220605143815.2330891-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org The comment about the page cache is rather stale; the buffer cache will read into the page cache if the buffer isn't present, and the page cache will not take any locks if the page is present. Signed-off-by: Matthew Wilcox (Oracle) --- fs/ext4/super.c | 81 ++++++++++++------------------------------------- 1 file changed, 20 insertions(+), 61 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 450c918d68fc..1780649ed224 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1506,8 +1506,6 @@ static int ext4_mark_dquot_dirty(struct dquot *dquot); static int ext4_write_info(struct super_block *sb, int type); static int ext4_quota_on(struct super_block *sb, int type, int format_id, const struct path *path); -static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data, - size_t len, loff_t off); static ssize_t ext4_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); static int ext4_quota_enable(struct super_block *sb, int type, int format_id, @@ -1535,7 +1533,7 @@ static const struct dquot_operations ext4_quota_operations = { static const struct quotactl_ops ext4_qctl_operations = { .quota_on = ext4_quota_on, .quota_off = ext4_quota_off, - .quota_sync = dquot_quota_sync, + .quota_sync = generic_quota_sync, .get_state = dquot_get_state, .set_info = dquot_set_dqinfo, .get_dqblk = dquot_get_dqblk, @@ -1559,7 +1557,7 @@ static const struct super_operations ext4_sops = { .statfs = ext4_statfs, .show_options = ext4_show_options, #ifdef CONFIG_QUOTA - .quota_read = ext4_quota_read, + .quota_read = generic_quota_read, .quota_write = ext4_quota_write, .get_dquots = ext4_get_dquots, #endif @@ -6856,55 +6854,15 @@ static int ext4_quota_off(struct super_block *sb, int type) return dquot_quota_off(sb, type); } -/* Read data from quotafile - avoid pagecache and such because we cannot afford - * acquiring the locks... As quota files are never truncated and quota code - * itself serializes the operations (and no one else should touch the files) - * we don't have to be afraid of races */ -static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data, - size_t len, loff_t off) -{ - struct inode *inode = sb_dqopt(sb)->files[type]; - ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb); - int offset = off & (sb->s_blocksize - 1); - int tocopy; - size_t toread; - struct buffer_head *bh; - loff_t i_size = i_size_read(inode); - - if (off > i_size) - return 0; - if (off+len > i_size) - len = i_size-off; - toread = len; - while (toread > 0) { - tocopy = sb->s_blocksize - offset < toread ? - sb->s_blocksize - offset : toread; - bh = ext4_bread(NULL, inode, blk, 0); - if (IS_ERR(bh)) - return PTR_ERR(bh); - if (!bh) /* A hole? */ - memset(data, 0, tocopy); - else - memcpy(data, bh->b_data+offset, tocopy); - brelse(bh); - offset = 0; - toread -= tocopy; - data += tocopy; - blk++; - } - return len; -} - /* Write to quotafile (we know the transaction is already started and has * enough credits) */ static ssize_t ext4_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off) { struct inode *inode = sb_dqopt(sb)->files[type]; - ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb); - int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1); - int retries = 0; - struct buffer_head *bh; + int err = 0, offset = off & (sb->s_blocksize - 1); + struct buffer_head *bh, *head; + struct folio *folio; handle_t *handle = journal_current_handle(); if (!handle) { @@ -6924,20 +6882,21 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type, return -EIO; } - do { - bh = ext4_bread(handle, inode, blk, - EXT4_GET_BLOCKS_CREATE | - EXT4_GET_BLOCKS_METADATA_NOFAIL); - } while (PTR_ERR(bh) == -ENOSPC && - ext4_should_retry_alloc(inode->i_sb, &retries)); - if (IS_ERR(bh)) - return PTR_ERR(bh); - if (!bh) + folio = read_mapping_folio(inode->i_mapping, off / PAGE_SIZE, NULL); + if (IS_ERR(folio)) + return PTR_ERR(folio); + head = folio_buffers(folio); + if (!head) + head = alloc_page_buffers(&folio->page, sb->s_blocksize, false); + if (!head) goto out; + bh = head; + while ((bh_offset(bh) + sb->s_blocksize) <= (off % PAGE_SIZE)) + bh = bh->b_this_page; BUFFER_TRACE(bh, "get write access"); err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE); if (err) { - brelse(bh); + folio_put(folio); return err; } lock_buffer(bh); @@ -6945,14 +6904,14 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type, flush_dcache_page(bh->b_page); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, NULL, bh); - brelse(bh); out: + folio_put(folio); + if (err) + return err; if (inode->i_size < off + len) { i_size_write(inode, off + len); EXT4_I(inode)->i_disksize = inode->i_size; - err2 = ext4_mark_inode_dirty(handle, inode); - if (unlikely(err2 && !err)) - err = err2; + err = ext4_mark_inode_dirty(handle, inode); } return err ? err : len; } -- 2.35.1