Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758544AbYLCUZB (ORCPT ); Wed, 3 Dec 2008 15:25:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756105AbYLCT55 (ORCPT ); Wed, 3 Dec 2008 14:57:57 -0500 Received: from kroah.org ([198.145.64.141]:56634 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751662AbYLCT5u (ORCPT ); Wed, 3 Dec 2008 14:57:50 -0500 Date: Wed, 3 Dec 2008 11:56:18 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Frederic Bohe , Ext4 Developers List Subject: [patch 086/104] ext4: fix initialization of UNINIT bitmap blocks Message-ID: <20081203195618.GI8950@kroah.com> References: <20081203193901.715896543@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="ext4-fix-initialization-of-uninit-bitmap-blocks.patch" In-Reply-To: <20081203194725.GA8950@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3252 Lines: 87 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Frederic Bohe (cherry picked from commit c806e68f5647109350ec546fee5b526962970fd2) This fixes a bug which caused on-line resizing of filesystems with a 1k blocksize to fail. The root cause of this bug was the fact that if an uninitalized bitmap block gets read in by userspace (which e2fsprogs does try to avoid, but can happen when the blocksize is less than the pagesize and an adjacent blocks is read into memory) ext4_read_block_bitmap() was erroneously depending on the buffer uptodate flag to decide whether it needed to initialize the bitmap block in memory --- i.e., to set the standard set of blocks in use by a block group (superblock, bitmaps, inode table, etc.). Essentially, ext4_read_block_bitmap() assumed it was the only routine that might try to read a block containing a block bitmap, which is simply not true. To fix this, ext4_read_block_bitmap() and ext4_read_inode_bitmap() must always initialize uninitialized bitmap blocks. Once a block or inode is allocated out of that bitmap, it will be marked as initialized in the block group descriptor, so in general this won't result any extra unnecessary work. Signed-off-by: Frederic Bohe Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/balloc.c | 4 +++- fs/ext4/ialloc.c | 4 +++- fs/ext4/mballoc.c | 4 +++- 3 files changed, 9 insertions(+), 3 deletions(-) --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -318,9 +318,11 @@ ext4_read_block_bitmap(struct super_bloc block_group, bitmap_blk); return NULL; } - if (bh_uptodate_or_lock(bh)) + if (buffer_uptodate(bh) && + !(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) return bh; + lock_buffer(bh); spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group)); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { ext4_init_block_bitmap(sb, bh, block_group, desc); --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -115,9 +115,11 @@ ext4_read_inode_bitmap(struct super_bloc block_group, bitmap_blk); return NULL; } - if (bh_uptodate_or_lock(bh)) + if (buffer_uptodate(bh) && + !(desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) return bh; + lock_buffer(bh); spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group)); if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { ext4_init_inode_bitmap(sb, bh, block_group, desc); --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -784,9 +784,11 @@ static int ext4_mb_init_cache(struct pag if (bh[i] == NULL) goto out; - if (bh_uptodate_or_lock(bh[i])) + if (buffer_uptodate(bh[i]) && + !(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) continue; + lock_buffer(bh[i]); spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { ext4_init_block_bitmap(sb, bh[i], -- 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/