ext4: fix locking typo in mballoc which could cause soft lockup hangs

Smatch (http://repo.or.cz/w/smatch.git/) complains about the locking in
ext4_mb_add_n_trim() from fs/ext4/mballoc.c

  4438          list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
  4439                                                  pa_inode_list) {
  4440                  spin_lock(&tmp_pa->pa_lock);
  4441                  if (tmp_pa->pa_deleted) {
  4442                          spin_unlock(&pa->pa_lock);
  4443                          continue;
  4444                  }

Brown paper bag time...

Reported-by: Dan Carpenter <[email protected]>
Reviewed-by: Eric Sandeen <[email protected]>
Reviewed-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Cc: [email protected]
This commit is contained in:
Theodore Ts'o 2009-03-27 19:43:21 -04:00
commit e7c9e3e99a

View file

@ -4392,7 +4392,7 @@ static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
pa_inode_list) {
spin_lock(&tmp_pa->pa_lock);
if (tmp_pa->pa_deleted) {
spin_unlock(&pa->pa_lock);
spin_unlock(&tmp_pa->pa_lock);
continue;
}
if (!added && pa->pa_free < tmp_pa->pa_free) {