From: "Kiselev, Oleg" <okiselev@amazon.com> stable inclusion from stable-v5.10.138 commit 80288883294c5b4ed18bae0d8bd9c4a12f297074 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- fs/ext4/resize.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index ec1a1f69dd59..4fefc5a213ad 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1969,6 +1969,16 @@ 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); -- 2.20.1