From mboxrd@z Thu Jan 1 00:00:00 1970 From: Namjae Jeon Subject: [PATCH] fat: fix data past EOF resulting from fsx testsuite Date: Thu, 30 Oct 2014 14:04:08 +0900 Message-ID: <000001cff3fe$effbc0d0$cff34270$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org To: OGAWA Hirofumi , Andrew Morton Return-path: Received: from mailout1.samsung.com ([203.254.224.24]:40468 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965AbaJ3FEN (ORCPT ); Thu, 30 Oct 2014 01:04:13 -0400 Received: from epcpsbgr2.samsung.com (u142.gpu120.samsung.co.kr [203.254.230.142]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NE80074HREZ21C0@mailout1.samsung.com> for linux-fsdevel@vger.kernel.org; Thu, 30 Oct 2014 14:04:11 +0900 (KST) Content-language: ko Sender: linux-fsdevel-owner@vger.kernel.org List-ID: When running FSX with direct I/O mode, fsx resulted in DATA past EOF issues. fsx ./file2 -Z -r 4096 -w 4096 ... .. truncating to largest ever: 0x907c fallocating to largest ever: 0x11137 truncating to largest ever: 0x2c6fe truncating to largest ever: 0x2cfdf fallocating to largest ever: 0x40000 Mapped Read: non-zero data past EOF (0x18628) page offset 0x629 is 0x2a4e ... .. The reason being, it is doing a truncate down, but the zeroing does not happen on the last block boundary when offset is not aligned. Even though it calls truncate_setsize()->truncate_inode_pages()-> truncate_inode_pages_range() and considers the partial zeroout but it retrieves the page using find_lock_page() - which only looks the page in the cache. So, zeroing out does not happen in case of direct IO. Make a truncate page based around block_truncate_page for FAT filesystem and invoke that helper to zerout in case the offset is not aligned with the blocksize. Signed-off-by: Namjae Jeon Signed-off-by: Amit Sahrawat --- fs/fat/fat.h | 1 + fs/fat/file.c | 2 ++ fs/fat/inode.c | 12 ++++++++++++ 3 files changed, 15 insertions(+) diff --git a/fs/fat/fat.h b/fs/fat/fat.h index eff027d..61801da 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -374,6 +374,7 @@ extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync); /* fat/inode.c */ +extern int fat_block_truncate_page(struct inode *inode, loff_t from); extern void fat_attach(struct inode *inode, loff_t i_pos); extern void fat_detach(struct inode *inode); extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); diff --git a/fs/fat/file.c b/fs/fat/file.c index f2c73ae..a848502 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -526,6 +526,8 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) down_write(&MSDOS_I(inode)->truncate_lock); truncate_setsize(inode, attr->ia_size); fat_truncate_blocks(inode, attr->ia_size); + if (inode->i_size & (inode->i_sb->s_blocksize - 1)) + fat_block_truncate_page(inode, inode->i_size); up_write(&MSDOS_I(inode)->truncate_lock); } diff --git a/fs/fat/inode.c b/fs/fat/inode.c index f362796..57140f9 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -339,6 +339,18 @@ static sector_t _fat_bmap(struct address_space *mapping, sector_t block) return blocknr; } +/* + * fat_block_truncate_page() zeroes out a mapping from file offset `from' + * up to the end of the block which corresponds to `from'. + * This is required during truncate to physically zero out the tail end + * of that block so it doesn't yield old data if the file is later grown. + * Also, avoid causing failure from fsx for cases of "data past EOF" + */ +int fat_block_truncate_page(struct inode *inode, loff_t from) +{ + return block_truncate_page(inode->i_mapping, from, fat_get_block); +} + static const struct address_space_operations fat_aops = { .readpage = fat_readpage, .readpages = fat_readpages, -- 1.7.11-rc0