ext2: fix sleeping in atomic bugs on error

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>

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 1f3f4326bf3ce82d1a2fb350479ce59a13128fdb..c17ccc19b938e22d996476bc8567c5df22716daa 100644 (file)
--- 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;
        }