linux-stable.git/fs/ext4, branch v3.16.75

ext4: fix data corruption caused by overlapping unaligned and aligned IO

2019-09-23T20:12:04+00:00

commit 57a0da28ced8707cb9f79f071a016b9d005caf5a upstream.

Unaligned AIO must be serialized because the zeroing of partial blocks
of unaligned AIO can result in data corruption in case it's overlapping
another in flight IO.

Currently we wait for all unwritten extents before we submit unaligned
AIO which protects data in case of unaligned AIO is following overlapping
IO. However if a unaligned AIO is followed by overlapping aligned AIO we
can still end up corrupting data.

To fix this, we must make sure that the unaligned AIO is the only IO in
flight by waiting for unwritten extents conversion not just before the
IO submission, but right after it as well.

This problem can be reproduced by xfstest generic/538

Signed-off-by: Lukas Czerner 
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 3.16:
 - Test aio_mutex instead of unaligned_aio
 - Adjust context]
Signed-off-by: Ben Hutchings

ext4: actually request zeroing of inode table after grow

2019-09-23T20:11:53+00:00

commit 310a997fd74de778b9a4848a64be9cda9f18764a upstream.

It is never possible, that number of block groups decreases,
since only online grow is supported.

But after a growing occured, we have to zero inode tables
for just created new block groups.

Fixes: 19c5246d2516 ("ext4: add new online resize interface")
Signed-off-by: Kirill Tkhai 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Signed-off-by: Ben Hutchings

ext4: cleanup bh release code in ext4_ind_remove_space()

2019-08-20T18:01:56+00:00

commit 5e86bdda41534e17621d5a071b294943cae4376e upstream.

Currently, we are releasing the indirect buffer where we are done with
it in ext4_ind_remove_space(), so we can see the brelse() and
BUFFER_TRACE() everywhere.  It seems fragile and hard to read, and we
may probably forget to release the buffer some day.  This patch cleans
up the code by putting of the code which releases the buffers to the
end of the function.

Signed-off-by: zhangyi (F) 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Signed-off-by: Ben Hutchings

ext4: brelse all indirect buffer in ext4_ind_remove_space()

2019-08-20T18:01:56+00:00

commit 674a2b27234d1b7afcb0a9162e81b2e53aeef217 upstream.

All indirect buffers get by ext4_find_shared() should be released no
mater the branch should be freed or not. But now, we forget to release
the lower depth indirect buffers when removing space from the same
higher depth indirect block. It will lead to buffer leak and futher
more, it may lead to quota information corruption when using old quota,
consider the following case.

 - Create and mount an empty ext4 filesystem without extent and quota
   features,
 - quotacheck and enable the user & group quota,
 - Create some files and write some data to them, and then punch hole
   to some files of them, it may trigger the buffer leak problem
   mentioned above.
 - Disable quota and run quotacheck again, it will create two new
   aquota files and write the checked quota information to them, which
   probably may reuse the freed indirect block(the buffer and page
   cache was not freed) as data block.
 - Enable quota again, it will invoke
   vfs_load_quota_inode()->invalidate_bdev() to try to clean unused
   buffers and pagecache. Unfortunately, because of the buffer of quota
   data block is still referenced, quota code cannot read the up to date
   quota info from the device and lead to quota information corruption.

This problem can be reproduced by xfstests generic/231 on ext3 file
system or ext4 file system without extent and quota features.

This patch fix this problem by releasing the missing indirect buffers,
in ext4_ind_remove_space().

Reported-by: Hulk Robot 
Signed-off-by: zhangyi (F) 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Signed-off-by: Ben Hutchings

ext4: add missing brelse() in add_new_gdb_meta_bg()

2019-08-13T11:38:41+00:00

commit d64264d6218e6892edd832dc3a5a5857c2856c53 upstream.

Currently in add_new_gdb_meta_bg() there is a missing brelse of gdb_bh
in case ext4_journal_get_write_access() fails.
Additionally kvfree() is missing in the same error path. Fix it by
moving the ext4_journal_get_write_access() before the ext4 sb update as
Ted suggested and release n_group_desc and gdb_bh in case it fails.

Fixes: 61a9c11e5e7a ("ext4: add missing brelse() add_new_gdb_meta_bg()'s error path")
Signed-off-by: Lukas Czerner 
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ext4: fix data corruption caused by unaligned direct AIO

2019-08-13T11:38:41+00:00

commit 372a03e01853f860560eade508794dd274e9b390 upstream.

Ext4 needs to serialize unaligned direct AIO because the zeroing of
partial blocks of two competing unaligned AIOs can result in data
corruption.

However it decides not to serialize if the potentially unaligned aio is
past i_size with the rationale that no pending writes are possible past
i_size. Unfortunately if the i_size is not block aligned and the second
unaligned write lands past i_size, but still into the same block, it has
the potential of corrupting the previous unaligned write to the same
block.

This is (very simplified) reproducer from Frank

    // 41472 = (10 * 4096) + 512
    // 37376 = 41472 - 4096

    ftruncate(fd, 41472);
    io_prep_pwrite(iocbs[0], fd, buf[0], 4096, 37376);
    io_prep_pwrite(iocbs[1], fd, buf[1], 4096, 41472);

    io_submit(io_ctx, 1, &iocbs[1]);
    io_submit(io_ctx, 1, &iocbs[2]);

    io_getevents(io_ctx, 2, 2, events, NULL);

Without this patch the 512B range from 40960 up to the start of the
second unaligned write (41472) is going to be zeroed overwriting the data
written by the first write. This is a data corruption.

00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
*
00009200  30 30 30 30 30 30 30 30  30 30 30 30 30 30 30 30
*
0000a000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
*
0000a200  31 31 31 31 31 31 31 31  31 31 31 31 31 31 31 31

With this patch the data corruption is avoided because we will recognize
the unaligned_aio and wait for the unwritten extent conversion.

00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
*
00009200  30 30 30 30 30 30 30 30  30 30 30 30 30 30 30 30
*
0000a200  31 31 31 31 31 31 31 31  31 31 31 31 31 31 31 31
*
0000b200

Reported-by: Frank Sorenson 
Signed-off-by: Lukas Czerner 
Signed-off-by: Theodore Ts'o 
Fixes: e9e3bcecf44c ("ext4: serialize unaligned asynchronous DIO")
Signed-off-by: Ben Hutchings

ext4: fix crash during online resizing

2019-07-09T21:03:59+00:00

commit f96c3ac8dfc24b4e38fc4c2eba5fea2107b929d1 upstream.

When computing maximum size of filesystem possible with given number of
group descriptor blocks, we forget to include s_first_data_block into
the number of blocks. Thus for filesystems with non-zero
s_first_data_block it can happen that computed maximum filesystem size
is actually lower than current filesystem size which confuses the code
and eventually leads to a BUG_ON in ext4_alloc_group_tables() hitting on
flex_gd->count == 0. The problem can be reproduced like:

truncate -s 100g /tmp/image
mkfs.ext4 -b 1024 -E resize=262144 /tmp/image 32768
mount -t ext4 -o loop /tmp/image /mnt
resize2fs /dev/loop0 262145
resize2fs /dev/loop0 300000

Fix the problem by properly including s_first_data_block into the
computed number of filesystem blocks.

Fixes: 1c6bd7173d66 "ext4: convert file system to meta_bg if needed..."
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Ben Hutchings

ext4: add mask of ext4 flags to swap

2019-07-09T21:03:58+00:00

commit abdc644e8cbac2e9b19763680e5a7cf9bab2bee7 upstream.

The reason is that while swapping two inode, we swap the flags too.
Some flags such as EXT4_JOURNAL_DATA_FL can really confuse the things
since we're not resetting the address operations structure.  The
simplest way to keep things sane is to restrict the flags that can be
swapped.

Signed-off-by: yangerkun 
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ext4: update quota information while swapping boot loader inode

2019-07-09T21:03:58+00:00

commit aa507b5faf38784defe49f5e64605ac3c4425e26 upstream.

While do swap between two inode, they swap i_data without update
quota information. Also, swap_inode_boot_loader can do "revert"
somtimes, so update the quota while all operations has been finished.

Signed-off-by: yangerkun 
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 3.16:
 - Include 
 - dquot_initialize() does not return an erro
 - Adjust context]
Signed-off-by: Ben Hutchings

ext4: fix check of inode in swap_inode_boot_loader

2019-07-09T21:03:57+00:00

commit 67a11611e1a5211f6569044fbf8150875764d1d0 upstream.

Before really do swap between inode and boot inode, something need to
check to avoid invalid or not permitted operation, like does this inode
has inline data. But the condition check should be protected by inode
lock to avoid change while swapping. Also some other condition will not
change between swapping, but there has no problem to do this under inode
lock.

Signed-off-by: yangerkun 
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 3.16: There's no support or test for filesytem encryption]
Signed-off-by: Ben Hutchings