From ab4c54c643a01067669df8332b64e3f31b69e071 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 10 Oct 2022 18:36:07 +0800 Subject: [PATCH] btrfs: raid56: avoid double freeing for rbio if full_stripe_write() failed Currently if full_stripe_write() failed to allocate the pages for parity, it will call __free_raid_bio() first, then return -ENOMEM. But some caller of full_stripe_write() will also call __free_raid_bio() again, this would cause double freeing. And it's not a logically sound either, normally we should either free the memory at the same level where we allocated it, or let endio to handle everything. So this patch will solve the double freeing by make raid56_parity_write() to handle the error and free the rbio. Just like what we do in raid56_parity_recover(). Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/raid56.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 892005f..82c8e99 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -1632,10 +1632,8 @@ static int full_stripe_write(struct btrfs_raid_bio *rbio) int ret; ret = alloc_rbio_parity_pages(rbio); - if (ret) { - __free_raid_bio(rbio); + if (ret) return ret; - } ret = lock_stripe_add(rbio); if (ret == 0) @@ -1823,8 +1821,10 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc) */ if (rbio_is_full(rbio)) { ret = full_stripe_write(rbio); - if (ret) + if (ret) { + __free_raid_bio(rbio); goto fail; + } return; } @@ -1838,8 +1838,10 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc) list_add_tail(&rbio->plug_list, &plug->rbio_list); } else { ret = __raid56_parity_write(rbio); - if (ret) + if (ret) { + __free_raid_bio(rbio); goto fail; + } } return; -- 2.7.4