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authorKiselev, Oleg <okiselev@amazon.com>2022-07-20 07:27:48 +0300
committerTheodore Ts'o <tytso@mit.edu>2022-08-03 06:56:26 +0300
commit69cb8e9d8cd97cdf5e293b26d70a9dee3e35e6bd (patch)
tree4c04cf154e06fd8c06738c0bc78ce665902161d7 /fs
parent026d0d27c4882303e4b071ca6d996640cc2932c3 (diff)
downloadlinux-69cb8e9d8cd97cdf5e293b26d70a9dee3e35e6bd.tar.xz
ext4: avoid resizing to a partial cluster size
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>
Diffstat (limited to 'fs')
-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 5e3a893e600e..fea2a68d067b 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -2011,6 +2011,16 @@ 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);