diff options
| author | Kiselev, Oleg <okiselev@amazon.com> | 2022-07-20 04:27:48 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 11:18:35 +0200 |
| commit | a6805b3dcf5cd41f2ae3a03dca43411135b99849 (patch) | |
| tree | aa7cfe98999a1a03eae774295840ca693f07ce41 /fs/ext4/resize.c | |
| parent | 5bebfd6077266aed0e3db75278d0f7c3a620fa5c (diff) | |
ext4: avoid resizing to a partial cluster size
[ Upstream commit 69cb8e9d8cd97cdf5e293b26d70a9dee3e35e6bd ]
This patch avoids an attempt to resize the filesystem to an
unaligned cluster boundary. An online resize to a size that is not
integral to cluster size results in the last iteration attempting to
grow the fs by a negative amount, which trips a BUG_ON and leaves the fs
with a corrupted in-memory superblock.
Signed-off-by: Oleg Kiselev <okiselev@amazon.com>
Link: https://lore.kernel.org/r/0E92A0AB-4F16-4F1A-94B7-702CC6504FDE@amazon.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/ext4/resize.c')
| -rw-r--r-- | fs/ext4/resize.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 306003e29c4c..f0fc7fc579e6 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1979,6 +1979,16 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) } brelse(bh); + /* + * For bigalloc, trim the requested size to the nearest cluster + * boundary to avoid creating an unusable filesystem. We do this + * silently, instead of returning an error, to avoid breaking + * callers that blindly resize the filesystem to the full size of + * the underlying block device. + */ + if (ext4_has_feature_bigalloc(sb)) + n_blocks_count &= ~((1 << EXT4_CLUSTER_BITS(sb)) - 1); + retry: o_blocks_count = ext4_blocks_count(es); |