From: Milan Broz Make io reference counting more obvious. Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon --- drivers/md/dm-crypt.c | 20 ++++++++------------ 1 files changed, 8 insertions(+), 12 deletions(-) Index: linux-2.6.24/drivers/md/dm-crypt.c =================================================================== --- linux-2.6.24.orig/drivers/md/dm-crypt.c 2008-02-07 13:48:34.000000000 +0000 +++ linux-2.6.24/drivers/md/dm-crypt.c 2008-02-07 13:48:35.000000000 +0000 @@ -584,7 +584,6 @@ static void kcryptd_crypt_write_io_submi crypt_free_buffer_pages(cc, clone); bio_put(clone); io->error = -EIO; - crypt_dec_pending(io); return; } @@ -593,6 +592,9 @@ static void kcryptd_crypt_write_io_submi clone->bi_sector = cc->start + io->sector; io->sector += bio_sectors(clone); + + atomic_inc(&io->pending); + generic_make_request(clone); } static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io) @@ -610,7 +612,6 @@ static void kcryptd_crypt_write_convert_ clone = crypt_alloc_buffer(io, remaining); if (unlikely(!clone)) { io->error = -ENOMEM; - crypt_dec_pending(io); return; } @@ -625,16 +626,6 @@ static void kcryptd_crypt_write_convert_ if (unlikely(r < 0)) return; - /* Grab another reference to the io struct - * before we kick off the request */ - if (remaining) - atomic_inc(&io->pending); - - generic_make_request(clone); - - /* Do not reference clone after this - it - * may be gone already. */ - /* out of memory -> run queues */ if (unlikely(remaining)) congestion_wait(WRITE, HZ/100); @@ -645,10 +636,15 @@ static void kcryptd_crypt_write_convert( { struct crypt_config *cc = io->target->private; + /* + * Prevent io from disappearing until this function completes. + */ atomic_inc(&io->pending); crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector); kcryptd_crypt_write_convert_loop(io); + + crypt_dec_pending(io); } static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)