Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752792AbbFANAQ (ORCPT ); Mon, 1 Jun 2015 09:00:16 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49094 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751425AbbFANAK (ORCPT ); Mon, 1 Jun 2015 09:00:10 -0400 From: Michal Hocko To: Cc: Andrew Morton , Dave Chinner , Neil Brown , Johannes Weiner , Al Viro , Mel Gorman , Rik van Riel , Tetsuo Handa , LKML , linux-fsdevel@vger.kernel.org Subject: [RFC 1/2] mm: do not ignore mapping_gfp_mask in page cache allocation paths Date: Mon, 1 Jun 2015 15:00:02 +0200 Message-Id: <1433163603-13229-2-git-send-email-mhocko@suse.cz> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433163603-13229-1-git-send-email-mhocko@suse.cz> References: <1433163603-13229-1-git-send-email-mhocko@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2728 Lines: 76 page_cache_read, do_generic_file_read, __generic_file_splice_read and __ntfs_grab_cache_pages currently ignore mapping_gfp_mask when calling add_to_page_cache_lru which might cause recursion into fs down in the direct reclaim path if the mapping really relies on GFP_NOFS semantic. This doesn't seem to be the case now because page_cache_read (page fault path) doesn't seem to suffer from the reclaim recursion issues and do_generic_file_read and __generic_file_splice_read also shouldn't be called under fs locks which would deadlock in the reclaim path. Anyway it is better to obey mapping gfp mask and prevent from later breakage. Signed-off-by: Michal Hocko --- fs/ntfs/file.c | 2 +- fs/splice.c | 2 +- mm/filemap.c | 6 ++++-- 3 files changed, 6 insertions(+), 4 deletions(-) diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index 1da9b2d184dc..568c9dbc7e61 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -422,7 +422,7 @@ static inline int __ntfs_grab_cache_pages(struct address_space *mapping, } } err = add_to_page_cache_lru(*cached_page, mapping, index, - GFP_KERNEL); + GFP_KERNEL & mapping_gfp_mask(mapping)); if (unlikely(err)) { if (err == -EEXIST) continue; diff --git a/fs/splice.c b/fs/splice.c index 7d2fbb788fc5..ebd184f24e0d 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -360,7 +360,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, break; error = add_to_page_cache_lru(page, mapping, index, - GFP_KERNEL); + GFP_KERNEL & mapping_gfp_mask(mapping)); if (unlikely(error)) { page_cache_release(page); if (error == -EEXIST) diff --git a/mm/filemap.c b/mm/filemap.c index df533a10e8c3..adfc5d2e21c8 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1669,7 +1669,8 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos, goto out; } error = add_to_page_cache_lru(page, mapping, - index, GFP_KERNEL); + index, + GFP_KERNEL & mapping_gfp_mask(mapping)); if (error) { page_cache_release(page); if (error == -EEXIST) { @@ -1770,7 +1771,8 @@ static int page_cache_read(struct file *file, pgoff_t offset) if (!page) return -ENOMEM; - ret = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL); + ret = add_to_page_cache_lru(page, mapping, offset, + GFP_KERNEL & mapping_gfp_mask(mapping)); if (ret == 0) ret = mapping->a_ops->readpage(file, page); else if (ret == -EEXIST) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/