From: Toshiyuki Okajima Subject: [RESEND][PATCH 2/3 BUG,RFC] ext3: release block-device-mapping buffer_heads which have the filesystem private data for avoiding oom-killer Date: Thu, 20 Nov 2008 09:34:50 +0900 Message-ID: <20081120093450.c87b39ef.toshi.okajima@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: akpm@linux-foundation.org, tytso@mit.edu, viro@zeniv.linux.org.uk, sct@redhat.com, adilger@sun.com Return-path: Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Toshiyuki Okajima Implement releasepage() of a client of a block device to release its private data (journal_heads) and the page. The client is an ext3 filesystem. This function is called from releasepage() of the block-device mapping, blkdev_releasepage(). Signed-off-by: Toshiyuki Okajima --- fs/ext3/inode.c | 16 ++++++++++++++++ fs/ext3/super.c | 2 ++ include/linux/ext3_fs.h | 2 ++ 3 files changed, 20 insertions(+) diff -Nurp linux-2.6.28-rc4.orig/fs/ext3/inode.c linux-2.6.28-rc4/fs/ext3/inode.c --- linux-2.6.28-rc4.orig/fs/ext3/inode.c 2008-11-10 09:36:15.000000000 +0900 +++ linux-2.6.28-rc4/fs/ext3/inode.c 2008-11-11 09:31:13.000000000 +0900 @@ -1680,6 +1680,28 @@ static int ext3_releasepage(struct page } /* + * ext3_release_metadata: try to release own page. + * The mapping of this page is block device's. Therefore try_to_free_buffers() + * cannot release it. As a result, a function which releases own page is + * required. + */ +int ext3_release_metadata(void *client, struct page *page, gfp_t wait) +{ + struct super_block *sb = (struct super_block*)client; + journal_t *journal; + + WARN_ON(PageChecked(page)); + if (!page_has_buffers(page)) + return 0; + BUG_ON(EXT3_SB(sb) == NULL); + journal = EXT3_SB(sb)->s_journal; + if (journal != NULL) + return journal_try_to_free_buffers(journal, page, wait); + else + return try_to_free_buffers(page); +} + +/* * If the O_DIRECT write will extend the file then add this inode to the * orphan list. So recovery will truncate it back to the original size * if the machine crashes during the write. diff -Nurp linux-2.6.28-rc4.orig/fs/ext3/super.c linux-2.6.28-rc4/fs/ext3/super.c --- linux-2.6.28-rc4.orig/fs/ext3/super.c 2008-11-10 09:36:15.000000000 +0900 +++ linux-2.6.28-rc4/fs/ext3/super.c 2008-11-11 09:01:53.000000000 +0900 @@ -2972,6 +2972,8 @@ static struct file_system_type ext3_fs_t .name = "ext3", .get_sb = ext3_get_sb, .kill_sb = kill_block_super, + .release_metadata + = ext3_release_metadata, .fs_flags = FS_REQUIRES_DEV, }; diff -Nurp linux-2.6.28-rc4.orig/include/linux/ext3_fs.h linux-2.6.28-rc4/include/linux/ext3_fs.h --- linux-2.6.28-rc4.orig/include/linux/ext3_fs.h 2008-11-10 09:36:15.000000000 +0900 +++ linux-2.6.28-rc4/include/linux/ext3_fs.h 2008-11-10 18:33:52.000000000 +0900 @@ -841,6 +841,8 @@ extern void ext3_get_inode_flags(struct extern void ext3_set_aops(struct inode *inode); extern int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len); +extern int ext3_release_metadata(void *client, struct page *page, + gfp_t wait); /* ioctl.c */ extern int ext3_ioctl (struct inode *, struct file *, unsigned int,