[PATCH v2] ext4: Fix incorrect group count in ext4_fill_super error message

From: Josh Triplett
Date: Sat Mar 28 2020 - 19:44:14 EST


ext4_fill_super doublechecks the number of groups before mounting; if
that check fails, the resulting error message prints the group count
from the ext4_sb_info sbi, which hasn't been set yet. Move the
assignment to sbi->s_groups_count above its use in the error message.

Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Fixes: 4ec1102813798 ("ext4: Add sanity checks for the superblock before mounting the filesystem")
---
v2: Rather than using the computed group count value in blocks_count,
move the assignment to sbi->s_groups_count up and keep using that. That
makes the code, and the patch, simpler to read and understand.

fs/ext4/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0c7c4adb664e..6692bc48520a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4285,6 +4285,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
le32_to_cpu(es->s_first_data_block) +
EXT4_BLOCKS_PER_GROUP(sb) - 1);
do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
+ sbi->s_groups_count = blocks_count;
if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
"(block count %llu, first data block %u, "
@@ -4294,7 +4295,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
EXT4_BLOCKS_PER_GROUP(sb));
goto failed_mount;
}
- sbi->s_groups_count = blocks_count;
sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
--
2.26.0