[PATCH 5.14 12/48] ext2: fix sleeping in atomic bugs on error

Greg Kroah-Hartman
2021-10-08T11:37:15Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 372d1f3e1bfede719864d0d1fbf3146b1e638c88 ]

The ext2_error() function syncs the filesystem so it sleeps. The caller
is holding a spinlock so it's not allowed to sleep.

ext2_statfs() <- disables preempt
-> ext2_count_free_blocks()
-> ext2_get_group_desc()

Fix this by using WARN() to print an error message and a stack trace
instead of using ext2_error().

Link: https://lore.kernel.org/r/20210921203233.GA16529@kili
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext2/balloc.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 1f3f4326bf3c..c17ccc19b938 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -48,10 +48,9 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
struct ext2_sb_info *sbi = EXT2_SB(sb);

if (block_group >= sbi->s_groups_count) {
- ext2_error (sb, "ext2_get_group_desc",
- "block_group >= groups_count - "
- "block_group = %d, groups_count = %lu",
- block_group, sbi->s_groups_count);
+ WARN(1, "block_group >= groups_count - "
+ "block_group = %d, groups_count = %lu",
+ block_group, sbi->s_groups_count);

return NULL;
}
@@ -59,10 +58,9 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(sb);
offset = block_group & (EXT2_DESC_PER_BLOCK(sb) - 1);
if (!sbi->s_group_desc[group_desc]) {
- ext2_error (sb, "ext2_get_group_desc",
- "Group descriptor not loaded - "
- "block_group = %d, group_desc = %lu, desc = %lu",
- block_group, group_desc, offset);
+ WARN(1, "Group descriptor not loaded - "
+ "block_group = %d, group_desc = %lu, desc = %lu",
+ block_group, group_desc, offset);
return NULL;
}

--
2.33.0