From 92d2d51544468a7b378a7213c0c27202f3e1b7c1 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 14 Apr 2022 21:57:49 -0400 Subject: [PATCH] ext4: force overhead calculation if the s_overhead_cluster makes no sense commit 85d825dbf4899a69407338bae462a59aa9a37326 upstream. If the file system does not use bigalloc, calculating the overhead is cheap, so force the recalculation of the overhead so we don't have to trust the precalculated overhead in the superblock. Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 5cb9910f6e6d..6893b87c7354 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4423,9 +4423,18 @@ no_journal: * Get the # of file system overhead blocks from the * superblock if present. */ - if (es->s_overhead_clusters) - sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters); - else { + sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters); + /* ignore the precalculated value if it is ridiculous */ + if (sbi->s_overhead > ext4_blocks_count(es)) + sbi->s_overhead = 0; + /* + * If the bigalloc feature is not enabled recalculating the + * overhead doesn't take long, so we might as well just redo + * it to make sure we are using the correct value. + */ + if (!ext4_has_feature_bigalloc(sb)) + sbi->s_overhead = 0; + if (sbi->s_overhead == 0) { err = ext4_calculate_overhead(sb); if (err) goto failed_mount_wq;