From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932144Ab1HCX3b (ORCPT ); Wed, 3 Aug 2011 19:29:31 -0400 Received: from cantor2.suse.de ([195.135.220.15]:33828 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756181Ab1HCX2p (ORCPT ); Wed, 3 Aug 2011 19:28:45 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Aug 3 15:12:51 2011 Message-Id: <20110803221251.075701537@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 03 Aug 2011 15:01:30 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Maxim Patlasov , "Theodore Tso" Subject: [070/102] ext4: fix i_blocks/quota accounting when extent insertion fails In-Reply-To: <20110803221345.GA10346@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let us know. ------------------ From: Maxim Patlasov commit 7132de744ba76930d13033061018ddd7e3e8cd91 upstream. The current implementation of ext4_free_blocks() always calls dquot_free_block This looks quite sensible in the most cases: blocks to be freed are associated with inode and were accounted in quota and i_blocks some time ago. However, there is a case when blocks to free were not accounted by the time calling ext4_free_blocks() yet: 1. delalloc is on, write_begin pre-allocated some space in quota 2. write-back happens, ext4 allocates some blocks in ext4_ext_map_blocks() 3. then ext4_ext_map_blocks() gets an error (e.g. ENOSPC) from ext4_ext_insert_extent() and calls ext4_free_blocks(). In this scenario, ext4_free_blocks() calls dquot_free_block() who, in turn, decrements i_blocks for blocks which were not accounted yet (due to delalloc) After clean umount, e2fsck reports something like: > Inode 21, i_blocks is 5080, should be 5128. Fix? because i_blocks was erroneously decremented as explained above. The patch fixes the problem by passing the new flag EXT4_FREE_BLOCKS_NO_QUOT_UPDATE to ext4_free_blocks(), to request that the dquot_free_block() call be skipped. Signed-off-by: Maxim Patlasov Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4.h | 1 + fs/ext4/extents.c | 4 +++- fs/ext4/mballoc.c | 2 +- 3 files changed, 5 insertions(+), 2 deletions(-) --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -526,6 +526,7 @@ struct ext4_new_group_data { #define EXT4_FREE_BLOCKS_METADATA 0x0001 #define EXT4_FREE_BLOCKS_FORGET 0x0002 #define EXT4_FREE_BLOCKS_VALIDATED 0x0004 +#define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008 /* * ioctl commands --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3601,12 +3601,14 @@ int ext4_ext_map_blocks(handle_t *handle err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (err) { + int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? + EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; /* free data blocks we just allocated */ /* not a good idea to call discard here directly, * but otherwise we'd need to call it every free() */ ext4_discard_preallocations(inode); ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex), - ext4_ext_get_actual_len(&newex), 0); + ext4_ext_get_actual_len(&newex), fb_flags); goto out2; } --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4637,7 +4637,7 @@ do_more: } ext4_mark_super_dirty(sb); error_return: - if (freed) + if (freed && !(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE)) dquot_free_block(inode, freed); brelse(bitmap_bh); ext4_std_error(sb, err);