Commit 36cb0f52 authored by Kemeng Shi's avatar Kemeng Shi Committed by Theodore Ts'o
Browse files

ext4: protect pa->pa_free in ext4_discard_allocated_blocks 



If ext4_mb_mark_diskspace_used fails in ext4_mb_new_blocks, we may
discard pa already in list. Protect pa with pa_lock to avoid race.

Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: default avatarOjaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-7-shikemeng@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 1afdc588

fs/ext4/mballoc.c

+4 −1
Original line number Diff line number Diff line
@@ -4267,8 +4267,11 @@ static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) 
		ext4_mb_unload_buddy(&e4b);

		return;

	}

	if (pa->pa_type == MB_INODE_PA)

	if (pa->pa_type == MB_INODE_PA) {

		spin_lock(&pa->pa_lock);

		pa->pa_free += ac->ac_b_ex.fe_len;

		spin_unlock(&pa->pa_lock);

	}

}



/*