From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: [PATCH 2/3] mm: don't TestClearPageError in __filemap_fdatawait_range Date: Sun, 5 Mar 2017 08:35:34 -0500 Message-ID: <20170305133535.6516-3-jlayton@redhat.com> References: <20170305133535.6516-1-jlayton@redhat.com> Return-path: In-Reply-To: <20170305133535.6516-1-jlayton@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: viro@zeniv.linux.org.uk, konishi.ryusuke@lab.ntt.co.jp Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nilfs@vger.kernel.org The -EIO returned here can end up overriding whatever error is marked in the address space. This means that an -ENOSPC error (AS_ENOSPC) can end up being turned into -EIO if a page gets PG_error set on it during error handling. Arguably, that's a bug in the writeback code, but... Read errors are also tracked on a per page level using PG_error. Suppose we have a read error on a page, and then that page is subsequently dirtied by overwriting the whole page. Writeback doesn't clear PG_error, so we can then end up successfully writing back that page and still return -EIO on fsync. Since the handling of this bit is somewhat inconsistent across subsystems, let's just rely on marking the address space when there are writeback errors. Signed-off-by: Jeff Layton --- mm/filemap.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 3f9afded581b..2b0b4ff4668b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -375,17 +375,16 @@ int filemap_flush(struct address_space *mapping) } EXPORT_SYMBOL(filemap_flush); -static int __filemap_fdatawait_range(struct address_space *mapping, +static void __filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { pgoff_t index = start_byte >> PAGE_SHIFT; pgoff_t end = end_byte >> PAGE_SHIFT; struct pagevec pvec; int nr_pages; - int ret = 0; if (end_byte < start_byte) - goto out; + return; pagevec_init(&pvec, 0); while ((index <= end) && @@ -402,14 +401,10 @@ static int __filemap_fdatawait_range(struct address_space *mapping, continue; wait_on_page_writeback(page); - if (TestClearPageError(page)) - ret = -EIO; } pagevec_release(&pvec); cond_resched(); } -out: - return ret; } /** @@ -429,14 +424,8 @@ static int __filemap_fdatawait_range(struct address_space *mapping, int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { - int ret, ret2; - - ret = __filemap_fdatawait_range(mapping, start_byte, end_byte); - ret2 = filemap_check_errors(mapping); - if (!ret) - ret = ret2; - - return ret; + __filemap_fdatawait_range(mapping, start_byte, end_byte); + return filemap_check_errors(mapping); } EXPORT_SYMBOL(filemap_fdatawait_range); -- 2.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org