| Submitter | Tao Ma |
|---|---|
| Date | March 3, 2011, 1:59 p.m. |
| Message ID | <1299160774-2337-1-git-send-email-tm@tao.ma> |
| Download | mbox | patch |
| Permalink | /patch/85288/ |
| State | Accepted |
| Headers | show |
Comments
On Thu, 3 Mar 2011, Tao Ma wrote: > From: Tao Ma <boyu.mt@taobao.com> > > In a bs=4096 volume, if we call FITRIM with the following parameter as > fstrim_range(start = 102400, len = 134144000, minlen = 10240), > we will trigger a BUG_ON. > BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); > > Mar 4 00:55:52 boyu-tm kernel: ------------[ cut here ]------------ > Mar 4 00:55:52 boyu-tm kernel: kernel BUG at fs/ext4/mballoc.c:1506! > Mar 4 01:21:09 boyu-tm kernel: Code: d4 00 00 00 00 49 89 fe 8b 56 0c 44 8b 7e 04 89 55 c4 48 8b 4f 28 89 d6 44 01 fe 48 63 d6 48 8b 41 18 48 c1 e0 03 48 39 c2 76 04 <0f> 0b eb fe 48 8b 55 b0 8b 47 34 3b 42 08 74 04 0f 0b eb fe 48 > Mar 4 01:21:09 boyu-tm kernel: RIP [<ffffffffa053eb42>] mb_mark_used+0x47/0x26c [ext4] > Mar 4 01:21:09 boyu-tm kernel: RSP <ffff880121e45c38> > Mar 4 01:21:09 boyu-tm kernel: ---[ end trace 9f461696f6a9dcf2 ]--- > > The reason is that in ext4_trim_fs, the last_block is checked wrongly. > if (len >= EXT4_BLOCKS_PER_GROUP(sb)) > len -= (EXT4_BLOCKS_PER_GROUP(sb) - first_block); > else > last_block = first_block + len; > > So if len < EXT4_BLOCKS_PER_GROUP while first_block + len > EXT4_BLOCKS_PER_GROUP, > last_block will be set to a overflow value which exceeds EXT4_BLOCKS_PER_GROUP. > > This patch fixes it and adjusts len accordingly. > > Cc: Lukas Czerner <lczerner@redhat.com> > Cc: "Theodore Ts'o" <tytso@mit.edu> > Signed-off-by: Tao Ma <boyu.mt@taobao.com> > --- > fs/ext4/mballoc.c | 11 ++++++++--- > 1 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 29d7d17..290b36c 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -4889,10 +4889,15 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) > break; > } > > - if (len >= EXT4_BLOCKS_PER_GROUP(sb)) > - len -= (EXT4_BLOCKS_PER_GROUP(sb) - first_block); > - else > + /* > + * For all the groups except the last one, last block will > + * always be EXT4_BLOCKS_PER_GROUP(sb), so we only need to > + * change it for the last group in which case start + > + * len < EXT4_BLOCKS_PER_GROUP(sb). > + */ > + if (first_block + len < EXT4_BLOCKS_PER_GROUP(sb)) > last_block = first_block + len; > + len -= last_block - first_block; > > if (e4b.bd_info->bb_free >= minlen) { > cnt = ext4_trim_all_free(sb, &e4b, first_block, > Looks good. Thanks! -Lukas -- 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
Hi Christoph, On 03/03/2011 10:11 PM, Christoph Hellwig wrote: > On Thu, Mar 03, 2011 at 09:59:34PM +0800, Tao Ma wrote: >> From: Tao Ma<boyu.mt@taobao.com> >> >> In a bs=4096 volume, if we call FITRIM with the following parameter as >> fstrim_range(start = 102400, len = 134144000, minlen = 10240), > Can you add a xfstests regression test for this particular invocation? > We already have Lukas' fstrim.c tester in the tree, so it could be a > simple wrapper around it. Actually these numbers are related to the block size of a ext4 volume. To be more specific, with the above number, we have first_block + block_len > EXT4_BLOCKS_PER_GROUP while block_len < EXT4_BLOCKS_PER_GROUP. So do you think it is generic enough for a test case in xfstests since now this tool kit is also used to test xfs and btrfs? Regards, Tao -- 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
On Thu, Mar 03, 2011 at 11:33:35PM +0800, Tao Ma wrote: > Actually these numbers are related to the block size of a ext4 volume. > To be more specific, with the above number, we have > first_block + block_len > EXT4_BLOCKS_PER_GROUP while > block_len < EXT4_BLOCKS_PER_GROUP. > So do you think it is generic enough for a test case in xfstests > since now this > tool kit is also used to test xfs and btrfs? xfstests also allows filesystem-specific tests. Most of the specific tests are for xfs, but there are few for udf right now as well. -- 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
Hi Ted, This is a fix for kernel panic in ext4. So any comment for it? Regards, Tao On 03/03/2011 09:59 PM, Tao Ma wrote: > From: Tao Ma <boyu.mt@taobao.com> > > In a bs=4096 volume, if we call FITRIM with the following parameter as > fstrim_range(start = 102400, len = 134144000, minlen = 10240), > we will trigger a BUG_ON. > BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); > > Mar 4 00:55:52 boyu-tm kernel: ------------[ cut here ]------------ > Mar 4 00:55:52 boyu-tm kernel: kernel BUG at fs/ext4/mballoc.c:1506! > Mar 4 01:21:09 boyu-tm kernel: Code: d4 00 00 00 00 49 89 fe 8b 56 0c 44 8b 7e 04 89 55 c4 48 8b 4f 28 89 d6 44 01 fe 48 63 d6 48 8b 41 18 48 c1 e0 03 48 39 c2 76 04 <0f> 0b eb fe 48 8b 55 b0 8b 47 34 3b 42 08 74 04 0f 0b eb fe 48 > Mar 4 01:21:09 boyu-tm kernel: RIP [<ffffffffa053eb42>] mb_mark_used+0x47/0x26c [ext4] > Mar 4 01:21:09 boyu-tm kernel: RSP <ffff880121e45c38> > Mar 4 01:21:09 boyu-tm kernel: ---[ end trace 9f461696f6a9dcf2 ]--- > > The reason is that in ext4_trim_fs, the last_block is checked wrongly. > if (len >= EXT4_BLOCKS_PER_GROUP(sb)) > len -= (EXT4_BLOCKS_PER_GROUP(sb) - first_block); > else > last_block = first_block + len; > > So if len < EXT4_BLOCKS_PER_GROUP while first_block + len > EXT4_BLOCKS_PER_GROUP, > last_block will be set to a overflow value which exceeds EXT4_BLOCKS_PER_GROUP. > > This patch fixes it and adjusts len accordingly. > > Cc: Lukas Czerner <lczerner@redhat.com> > Cc: "Theodore Ts'o" <tytso@mit.edu> > Signed-off-by: Tao Ma <boyu.mt@taobao.com> > --- > fs/ext4/mballoc.c | 11 ++++++++--- > 1 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 29d7d17..290b36c 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -4889,10 +4889,15 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) > break; > } > > - if (len >= EXT4_BLOCKS_PER_GROUP(sb)) > - len -= (EXT4_BLOCKS_PER_GROUP(sb) - first_block); > - else > + /* > + * For all the groups except the last one, last block will > + * always be EXT4_BLOCKS_PER_GROUP(sb), so we only need to > + * change it for the last group in which case start + > + * len < EXT4_BLOCKS_PER_GROUP(sb). > + */ > + if (first_block + len < EXT4_BLOCKS_PER_GROUP(sb)) > last_block = first_block + len; > + len -= last_block - first_block; > > if (e4b.bd_info->bb_free >= minlen) { > cnt = ext4_trim_all_free(sb, &e4b, first_block, -- 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
Thanks, added to the ext4 patch queue. My apologies for the delay. - Ted On Thu, Mar 03, 2011 at 09:59:34PM +0800, Tao Ma wrote: > From: Tao Ma <boyu.mt@taobao.com> > > In a bs=4096 volume, if we call FITRIM with the following parameter as > fstrim_range(start = 102400, len = 134144000, minlen = 10240), > we will trigger a BUG_ON. > BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); > -- 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
Patch
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 29d7d17..290b36c 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4889,10 +4889,15 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) break; } - if (len >= EXT4_BLOCKS_PER_GROUP(sb)) - len -= (EXT4_BLOCKS_PER_GROUP(sb) - first_block); - else + /* + * For all the groups except the last one, last block will + * always be EXT4_BLOCKS_PER_GROUP(sb), so we only need to + * change it for the last group in which case start + + * len < EXT4_BLOCKS_PER_GROUP(sb). + */ + if (first_block + len < EXT4_BLOCKS_PER_GROUP(sb)) last_block = first_block + len; + len -= last_block - first_block; if (e4b.bd_info->bb_free >= minlen) { cnt = ext4_trim_all_free(sb, &e4b, first_block,