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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: 5354b2af34 ("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
This commit is contained in:
Fabio M. De Francesco 2023-06-14 12:02:55 +02:00 committed by Theodore Ts'o
parent 1948279211
commit f451fd97dd
1 changed files with 8 additions and 10 deletions
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18
fs/ext4/balloc.c
View File

@ -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;
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];
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];
}
/*