ext4: drop the call to ext4_error() from ext4_get_group_info()

A recent patch added a call to ext4_error() which is problematic since
some callers of the ext4_get_group_info() function may be holding a
spinlock, whereas ext4_error() must never be called in atomic context.

This triggered a report from Syzbot: "BUG: sleeping function called from
invalid context in ext4_update_super" (see the link below).

Therefore, drop the call to ext4_error() from ext4_get_group_info(). In
the meantime use eight characters tabs instead of nine characters ones.

Reported-by: syzbot+4acc7d910e617b360859@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/00000000000070575805fdc6cdb2@google.com/
Fixes: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail")
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20230614100446.14337-1-fmdefrancesco@gmail.com

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 09c75a3..1f72f97 100644 (file)
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -324,17 +324,15 @@ static ext4_fsblk_t ext4_valid_block_bitmap_padding(struct super_block *sb,
 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
                                            ext4_group_t group)
 {
-        struct ext4_group_info **grp_info;
-        long indexv, indexh;
-
-        if (unlikely(group >= EXT4_SB(sb)->s_groups_count)) {
-                ext4_error(sb, "invalid group %u", group);
-                return NULL;
-        }
-        indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
-        indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
-        grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv);
-        return grp_info[indexh];
+       struct ext4_group_info **grp_info;
+       long indexv, indexh;
+
+       if (unlikely(group >= EXT4_SB(sb)->s_groups_count))
+               return NULL;
+       indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
+       indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
+       grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv);
+       return grp_info[indexh];
 }
 
 /*