[ Upstream commit a6b3bfe176e8a5b05ec4447404e412c2a3fc92cc ]
We observed a corruption during on-line resize of a file system that is
larger than 16 TiB with 4k block size. With having more then 2^32 blocks
resize_inode is turned off by default by mke2fs. The issue can be
reproduced on a smaller file system for convenience by explicitly
turning off resize_inode. An on-line resize across an 8 GiB boundary (the
size of a meta block group in this setup) then leads to a corruption:
dev=/dev/<some_dev> # should be >= 16 GiB
mkdir -p /corruption
/sbin/mke2fs -t ext4 -b 4096 -O ^resize_inode $dev $((2 * 2**21 - 2**15))
mount -t ext4 $dev /corruption
dd if=/dev/zero bs=4096 of=/corruption/test count=$((2*2**21 - 4*2**15))
sha1sum /corruption/test
# 79d2658b39dcfd77274e435b0934028adafaab11 /corruption/test
/sbin/resize2fs $dev $((2*2**21))
# drop page cache to force reload the block from disk
echo 1 > /proc/sys/vm/drop_caches
sha1sum /corruption/test
# 3c2abc63cbf1a94c9e6977e0fbd72cd832c4d5c3 /corruption/test
2^21 = 2^15*2^6 equals 8 GiB whereof 2^15 is the number of blocks per
block group and 2^6 are the number of block groups that make a meta
block group.
The last checksum might be different depending on how the file is laid
out across the physical blocks. The actual corruption occurs at physical
block 63*2^15 = 2064384 which would be the location of the backup of the
meta block group's block descriptor. During the on-line resize the file
system will be converted to meta_bg starting at s_first_meta_bg which is
2 in the example - meaning all block groups after 16 GiB. However, in
ext4_flex_group_add we might add block groups that are not part of the
first meta block group yet. In the reproducer we achieved this by
substracting the size of a whole block group from the point where the
meta block group would start. This must be considered when updating the
backup block group descriptors to follow the non-meta_bg layout. The fix
is to add a test whether the group to add is already part of the meta
block group or not.
Fixes: 01f795f9e0d67 ("ext4: add online resizing support for meta_bg and 64-bit file systems")
Cc: <stable@vger.kernel.org>
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Tested-by: Srivathsa Dara <srivathsa.d.dara@oracle.com>
Reviewed-by: Srivathsa Dara <srivathsa.d.dara@oracle.com>
Link: https://lore.kernel.org/r/20240215155009.94493-1-mheyne@amazon.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5d1935ac02ca5aee364a449a35e2977ea84509b0 ]
When we online resize an ext4 filesystem with a oversized flexbg_size,
mkfs.ext4 -F -G 67108864 $dev -b 4096 100M
mount $dev $dir
resize2fs $dev 16G
the following WARN_ON is triggered:
==================================================================
WARNING: CPU: 0 PID: 427 at mm/page_alloc.c:4402 __alloc_pages+0x411/0x550
Modules linked in: sg(E)
CPU: 0 PID: 427 Comm: resize2fs Tainted: G E 6.6.0-rc5+ #314
RIP: 0010:__alloc_pages+0x411/0x550
Call Trace:
<TASK>
__kmalloc_large_node+0xa2/0x200
__kmalloc+0x16e/0x290
ext4_resize_fs+0x481/0xd80
__ext4_ioctl+0x1616/0x1d90
ext4_ioctl+0x12/0x20
__x64_sys_ioctl+0xf0/0x150
do_syscall_64+0x3b/0x90
==================================================================
This is because flexbg_size is too large and the size of the new_group_data
array to be allocated exceeds MAX_ORDER. Currently, the minimum value of
MAX_ORDER is 8, the minimum value of PAGE_SIZE is 4096, the corresponding
maximum number of groups that can be allocated is:
(PAGE_SIZE << MAX_ORDER) / sizeof(struct ext4_new_group_data) ≈ 21845
And the value that is down-aligned to the power of 2 is 16384. Therefore,
this value is defined as MAX_RESIZE_BG, and the number of groups added
each time does not exceed this value during resizing, and is added multiple
times to complete the online resizing. The difference is that the metadata
in a flex_bg may be more dispersed.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231023013057.2117948-4-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b099eb87de105cf07cad731ded6fb40b2675108b ]
In commit 967ac8af4475 ("ext4: fix potential integer overflow in
alloc_flex_gd()"), an overflow check is added to alloc_flex_gd() to
prevent the allocated memory from being smaller than expected due to
the overflow. However, after kmalloc() is replaced with kmalloc_array()
in commit 6da2ec56059c ("treewide: kmalloc() -> kmalloc_array()"), the
kmalloc_array() function has an overflow check, so the above problem
will not occur. Therefore, the extra check is removed.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231023013057.2117948-3-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 658a52344fb139f9531e7543a6e0015b630feb38 ]
The maximum value of flexbg_size is 2^31, but the maximum value of int
is (2^31 - 1), so overflow may occur when the type of flexbg_size is
declared as int.
For example, when uninit_mask is initialized in ext4_alloc_group_tables(),
if flexbg_size == 2^31, the initialized uninit_mask is incorrect, and this
may causes set_flexbg_block_bitmap() to trigger a BUG_ON().
Therefore, the flexbg_size type is declared as unsigned int to avoid
overflow and memory waste.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231023013057.2117948-2-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 40dd7953f4d606c280074f10d23046b6812708ce upstream.
Wrong check of gdb backup in meta bg as following:
first_group is the first group of meta_bg which contains target group, so
target group is always >= first_group. We check if target group has gdb
backup by comparing first_group with [group + 1] and [group +
EXT4_DESC_PER_BLOCK(sb) - 1]. As group >= first_group, then [group + N] is
> first_group. So no copy of gdb backup in meta bg is done in
setup_new_flex_group_blocks.
No need to do gdb backup copy in meta bg from setup_new_flex_group_blocks
as we always copy updated gdb block to backups at end of
ext4_flex_group_add as following:
ext4_flex_group_add
/* no gdb backup copy for meta bg any more */
setup_new_flex_group_blocks
/* update current group number */
ext4_update_super
sbi->s_groups_count += flex_gd->count;
/*
* if group in meta bg contains backup is added, the primary gdb block
* of the meta bg will be copy to backup in new added group here.
*/
for (; gdb_num <= gdb_num_end; gdb_num++)
update_backups(...)
In summary, we can remove wrong gdb backup copy code in
setup_new_flex_group_blocks.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 31f13421c004a420c0e9d288859c9ea9259ea0cc upstream.
Commit 0aeaa2559d6d5 ("ext4: fix corruption when online resizing a 1K
bigalloc fs") found that primary superblock's offset in its group is
not equal to offset of backup superblock in its group when block size
is 1K and bigalloc is enabled. As group descriptor blocks are right
after superblock, we can't pass block number of gdb to update_backups
for the same reason.
The root casue of the issue above is that leading 1K padding block is
count as data block offset for primary block while backup block has no
padding block offset in its group.
Remove padding data block count to fix the issue for gdb backups.
For meta_bg case, update_backups treat blk_off as block number, do no
conversion in this case.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
