On 2021/2/17 下午6:59, Filipe Manana wrote:
On Tue, Feb 16, 2021 at 11:42 PM Qu Wenruo <quwenruo.bt...@gmx.com> wrote:



On 2021/2/16 下午10:45, Filipe Manana wrote:
On Wed, Jun 24, 2020 at 10:00 PM Qu Wenruo <w...@suse.com> wrote:

[BUG]
The following script could lead to corrupted btrfs fs after
btrfs-convert:

    fallocate -l 1G test.img
    mkfs.ext4 test.img
    mount test.img $mnt
    fallocate -l 200m $mnt/file1
    fallocate -l 200m $mnt/file2
    fallocate -l 200m $mnt/file3
    fallocate -l 200m $mnt/file4
    fallocate -l 205m $mnt/file1
    fallocate -l 205m $mnt/file2
    fallocate -l 205m $mnt/file3
    fallocate -l 205m $mnt/file4
    umount $mnt
    btrfs-convert test.img

The result btrfs will have a device extent beyond its boundary:
    pening filesystem to check...
    Checking filesystem on test.img
    UUID: bbcd7399-fd5b-41a7-81ae-d48bc6935e43
    [1/7] checking root items
    [2/7] checking extents
    ERROR: dev extent devid 1 physical offset 993198080 len 85786624 is beyond 
device boundary 1073741824
    ERROR: errors found in extent allocation tree or chunk allocation
    [3/7] checking free space cache
    [4/7] checking fs roots
    [5/7] checking only csums items (without verifying data)
    [6/7] checking root refs
    [7/7] checking quota groups skipped (not enabled on this FS)
    found 913960960 bytes used, error(s) found
    total csum bytes: 891500
    total tree bytes: 1064960
    total fs tree bytes: 49152
    total extent tree bytes: 16384
    btree space waste bytes: 144885
    file data blocks allocated: 2129063936
     referenced 1772728320

[CAUSE]
Btrfs-convert first collect all used blocks in the original fs, then
slightly enlarge the used blocks range as new btrfs data chunks.

However the enlarge part has a problem, that it doesn't take the device
boundary into consideration.

Thus it caused device extents and data chunks to go beyond device
boundary.

[FIX]
Just to extra check before inserting data chunks into
btrfs_convert_context::data_chunk.

Reported-by: Jiachen YANG <farsee...@gmail.com>
Signed-off-by: Qu Wenruo <w...@suse.com>

So, having upgraded a test box from btrfs-progs v5.6.1 to v5.10.1, I
now have btrfs/136 (fstests) failing:

$ ./check btrfs/136
FSTYP         -- btrfs
PLATFORM      -- Linux/x86_64 debian8 5.11.0-rc7-btrfs-next-81 #1 SMP
PREEMPT Tue Feb 16 12:29:07 WET 2021
MKFS_OPTIONS  -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1

btrfs/136 7s ... [failed, exit status 1]- output mismatch (see
/home/fdmanana/git/hub/xfstests/results//btrfs/136.out.bad)
      --- tests/btrfs/136.out 2020-06-10 19:29:03.818519162 +0100
      +++ /home/fdmanana/git/hub/xfstests/results//btrfs/136.out.bad
2021-02-16 14:31:30.669559188 +0000
      @@ -1,2 +1,3 @@
       QA output created by 136
      -Silence is golden
      +btrfs-convert failed
      +(see /home/fdmanana/git/hub/xfstests/results//btrfs/136.full for details)
      ...
      (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/136.out
/home/fdmanana/git/hub/xfstests/results//btrfs/136.out.bad'  to see
the entire diff)
Ran: btrfs/136
Failures: btrfs/136
Failed 1 of 1 tests

A bisect pointed to this patch.
Did you get this failure on your test box as well?

Nope.

Just tested with btrfs-progs v5.10.1, it passes:
   $ which btrfs
   /usr/bin/btrfs
   $ btrfs --version
   btrfs-progs v5.10.1
   $ sudo ./check btrfs/136
   FSTYP         -- btrfs
   PLATFORM      -- Linux/x86_64 btrfs-desktop-vm 5.11.0-rc4-custom+ #4
SMP PREEMPT Mon Jan 25 18:35:22 CST 2021
   MKFS_OPTIONS  -- /dev/mapper/test-scratch1
   MOUNT_OPTIONS -- /dev/mapper/test-scratch1 /mnt/scratch

   btrfs/136 6s ...  10s
   Ran: btrfs/136
   Passed all 1 tests

Would you mind to provide the 136.full to help debugging the failure?

Sure, here it is (also at https://pastebin.com/XhEX2dju):

root 10:06:39 /home/fdmanana/git/hub/xfstests (master)> cat
/home/fdmanana/git/hub/xfstests/results//btrfs/136.full
mke2fs 1.45.6 (20-Mar-2020)
Discarding device blocks: done
Creating filesystem with 5242880 4k blocks and 1310720 inodes
Filesystem UUID: 9519afc8-8ea0-42da-8ac5-3b4c20469dd1
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

Run fsstress -p 20 -n 100 -d
/home/fdmanana/btrfs-tests/scratch_1/ext3_ext4_data/ext3
tune2fs 1.45.6 (20-Mar-2020)
e2fsck 1.45.6 (20-Mar-2020)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 3A: Optimizing directories
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/dev/sdc: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sdc: 235/1310720 files (22.1% non-contiguous), 129757/5242880 blocks
Run fsstress -p 20 -n 100 -d
/home/fdmanana/btrfs-tests/scratch_1/ext3_ext4_data/ext4
ERROR: missing data block for bytenr 1048576
ERROR: failed to create ext2_saved/image: -2
WARNING: an error occurred during conversion, filesystem is partially

The bytenr is 1M, which looks related to the super block relocation code.

Thus it maybe disk layout related.

Your disk used here is 20G, although I tried the same size disk, it
still passes.

If you could reproduce it reliably (as you can do the bisect), mind to
take a e2image -Q dump?

Thanks,
Qu

created but not finalized and not mountable
create btrfs filesystem:
blocksize: 4096
nodesize: 16384
features: extref, skinny-metadata (default)
checksum: crc32c
creating ext2 image file
btrfs-convert failed
root 10:14:18 /home/fdmanana/git/hub/xfstests (master)>


Thanks



Thanks,
Qu

Thanks.

---
   convert/main.c | 2 ++
   1 file changed, 2 insertions(+)

diff --git a/convert/main.c b/convert/main.c
index c86ddd988c63..7709e9a6c085 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -669,6 +669,8 @@ static int calculate_available_space(struct 
btrfs_convert_context *cctx)
                          cur_off = cache->start;
                  cur_len = max(cache->start + cache->size - cur_off,
                                min_stripe_size);
+               /* data chunks should never exceed device boundary */
+               cur_len = min(cctx->total_bytes - cur_off, cur_len);
                  ret = add_merge_cache_extent(data_chunks, cur_off, cur_len);
                  if (ret < 0)
                          goto out;
--
2.27.0






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