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authorKiselev, Oleg <okiselev@amazon.com>2022-07-20 07:27:48 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-08-25 12:45:47 +0300
commit0082e99a9074ff88eff729c70c93454c8588d8e1 (patch)
tree0abf0dc5d458a3d9711d76ca2684eb69622a304d
parenta2522041d248a8c969cbbc97e1fc2cd8b4de120d (diff)
downloadlinux-0082e99a9074ff88eff729c70c93454c8588d8e1.tar.xz
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>
-rw-r--r--fs/ext4/resize.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index e5c2713aa11a..cb5a64293881 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1989,6 +1989,16 @@ 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);