From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Darrick J. Wong" Subject: Re: [PATCH] ext4: Fix scheduling in atomic on group checksum failure Date: Wed, 10 Feb 2016 09:52:46 -0800 Message-ID: <20160210175246.GA6338@birch.djwong.org> References: <1455112710-18765-1-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ted Tso , Dmitry Vyukov , linux-ext4@vger.kernel.org, stable@vger.kernel.org To: Jan Kara Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:30983 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751974AbcBJRwz (ORCPT ); Wed, 10 Feb 2016 12:52:55 -0500 Content-Disposition: inline In-Reply-To: <1455112710-18765-1-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Feb 10, 2016 at 02:58:30PM +0100, Jan Kara wrote: > When block group checksum is wrong, we call ext4_error() while holding > group spinlock from ext4_init_block_bitmap() or > ext4_init_inode_bitmap() which results in scheduling while in atomic. > Fix the issue by calling ext4_error() later after dropping the spinlock. > > CC: stable@vger.kernel.org > Reported-by: Dmitry Vyukov > Signed-off-by: Jan Kara Looks ok, so Reviewed-by: Darrick J. Wong --D > --- > fs/ext4/balloc.c | 7 ++++--- > fs/ext4/ialloc.c | 6 ++++-- > 2 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c > index ec0668a60678..fe1f50fe764f 100644 > --- a/fs/ext4/balloc.c > +++ b/fs/ext4/balloc.c > @@ -191,7 +191,6 @@ static int ext4_init_block_bitmap(struct super_block *sb, > /* If checksum is bad mark all blocks used to prevent allocation > * essentially implementing a per-group read-only flag. */ > if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { > - ext4_error(sb, "Checksum bad for group %u", block_group); > grp = ext4_get_group_info(sb, block_group); > if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) > percpu_counter_sub(&sbi->s_freeclusters_counter, > @@ -442,14 +441,16 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) > } > ext4_lock_group(sb, block_group); > if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { > - > err = ext4_init_block_bitmap(sb, bh, block_group, desc); > set_bitmap_uptodate(bh); > set_buffer_uptodate(bh); > ext4_unlock_group(sb, block_group); > unlock_buffer(bh); > - if (err) > + if (err) { > + ext4_error(sb, "Failed to init block bitmap for group " > + "%u: %d", block_group, err); > goto out; > + } > goto verify; > } > ext4_unlock_group(sb, block_group); > diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c > index 3fcfd50a2e8a..acc0ad56bf2f 100644 > --- a/fs/ext4/ialloc.c > +++ b/fs/ext4/ialloc.c > @@ -76,7 +76,6 @@ static int ext4_init_inode_bitmap(struct super_block *sb, > /* If checksum is bad mark all blocks and inodes use to prevent > * allocation, essentially implementing a per-group read-only flag. */ > if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { > - ext4_error(sb, "Checksum bad for group %u", block_group); > grp = ext4_get_group_info(sb, block_group); > if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) > percpu_counter_sub(&sbi->s_freeclusters_counter, > @@ -191,8 +190,11 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) > set_buffer_verified(bh); > ext4_unlock_group(sb, block_group); > unlock_buffer(bh); > - if (err) > + if (err) { > + ext4_error(sb, "Failed to init inode bitmap for group " > + "%u: %d", block_group, err); > goto out; > + } > return bh; > } > ext4_unlock_group(sb, block_group); > -- > 2.6.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html