From bd792f5690abd0ca80196050a070dad67d314b03 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 4 Mar 2021 15:57:18 +0100 Subject: [PATCH] Revert "dm: fix deadlock when swapping to encrypted device" This reverts commit 5c5bb514651aa174f15001b2624aca7b89976af6. It breaks the abi and is nothing that is needed for any Android devices. Bug: 161946584 Signed-off-by: Greg Kroah-Hartman Change-Id: I6f14268eae3250b096ed9e12c5d66bec8935dc11 --- drivers/md/dm-core.h | 4 --- drivers/md/dm-crypt.c | 1 - drivers/md/dm.c | 60 ----------------------------------- include/linux/device-mapper.h | 5 --- 4 files changed, 70 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 8cda3f7ddbae..7e426e4d1352 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -110,10 +110,6 @@ struct mapped_device { /* zero-length flush that will be cloned and submitted to targets */ struct bio flush_bio; - int swap_bios; - struct semaphore swap_bios_semaphore; - struct mutex swap_bios_lock; - struct dm_stats stats; struct kthread_worker kworker; diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index abcd653e52ed..23000b11682f 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -2861,7 +2861,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) wake_up_process(cc->write_thread); ti->num_flush_bios = 1; - ti->limit_swap_bios = true; return 0; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 0a08297c794d..3b6b2b8b7324 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -148,16 +148,6 @@ EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr); #define DM_NUMA_NODE NUMA_NO_NODE static int dm_numa_node = DM_NUMA_NODE; -#define DEFAULT_SWAP_BIOS (8 * 1048576 / PAGE_SIZE) -static int swap_bios = DEFAULT_SWAP_BIOS; -static int get_swap_bios(void) -{ - int latch = READ_ONCE(swap_bios); - if (unlikely(latch <= 0)) - latch = DEFAULT_SWAP_BIOS; - return latch; -} - /* * For mempools pre-allocation at the table loading time. */ @@ -947,11 +937,6 @@ void disable_write_zeroes(struct mapped_device *md) limits->max_write_zeroes_sectors = 0; } -static bool swap_bios_limit(struct dm_target *ti, struct bio *bio) -{ - return unlikely((bio->bi_opf & REQ_SWAP) != 0) && unlikely(ti->limit_swap_bios); -} - static void clone_endio(struct bio *bio) { blk_status_t error = bio->bi_status; @@ -989,11 +974,6 @@ static void clone_endio(struct bio *bio) } } - if (unlikely(swap_bios_limit(tio->ti, bio))) { - struct mapped_device *md = io->md; - up(&md->swap_bios_semaphore); - } - free_tio(tio); dec_pending(io, error); } @@ -1272,22 +1252,6 @@ void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start) } EXPORT_SYMBOL_GPL(dm_remap_zone_report); -static noinline void __set_swap_bios_limit(struct mapped_device *md, int latch) -{ - mutex_lock(&md->swap_bios_lock); - while (latch < md->swap_bios) { - cond_resched(); - down(&md->swap_bios_semaphore); - md->swap_bios--; - } - while (latch > md->swap_bios) { - cond_resched(); - up(&md->swap_bios_semaphore); - md->swap_bios++; - } - mutex_unlock(&md->swap_bios_lock); -} - static blk_qc_t __map_bio(struct dm_target_io *tio) { int r; @@ -1308,14 +1272,6 @@ static blk_qc_t __map_bio(struct dm_target_io *tio) atomic_inc(&io->io_count); sector = clone->bi_iter.bi_sector; - if (unlikely(swap_bios_limit(ti, clone))) { - struct mapped_device *md = io->md; - int latch = get_swap_bios(); - if (unlikely(latch != md->swap_bios)) - __set_swap_bios_limit(md, latch); - down(&md->swap_bios_semaphore); - } - r = ti->type->map(ti, clone); switch (r) { case DM_MAPIO_SUBMITTED: @@ -1330,18 +1286,10 @@ static blk_qc_t __map_bio(struct dm_target_io *tio) ret = generic_make_request(clone); break; case DM_MAPIO_KILL: - if (unlikely(swap_bios_limit(ti, clone))) { - struct mapped_device *md = io->md; - up(&md->swap_bios_semaphore); - } free_tio(tio); dec_pending(io, BLK_STS_IOERR); break; case DM_MAPIO_REQUEUE: - if (unlikely(swap_bios_limit(ti, clone))) { - struct mapped_device *md = io->md; - up(&md->swap_bios_semaphore); - } free_tio(tio); dec_pending(io, BLK_STS_DM_REQUEUE); break; @@ -1918,7 +1866,6 @@ static void cleanup_mapped_device(struct mapped_device *md) mutex_destroy(&md->suspend_lock); mutex_destroy(&md->type_lock); mutex_destroy(&md->table_devices_lock); - mutex_destroy(&md->swap_bios_lock); dm_mq_cleanup_mapped_device(md); } @@ -1993,10 +1940,6 @@ static struct mapped_device *alloc_dev(int minor) init_completion(&md->kobj_holder.completion); md->kworker_task = NULL; - md->swap_bios = get_swap_bios(); - sema_init(&md->swap_bios_semaphore, md->swap_bios); - mutex_init(&md->swap_bios_lock); - md->disk->major = _major; md->disk->first_minor = minor; md->disk->fops = &dm_blk_dops; @@ -3459,9 +3402,6 @@ MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); module_param(dm_numa_node, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations"); -module_param(swap_bios, int, S_IRUGO | S_IWUSR); -MODULE_PARM_DESC(swap_bios, "Maximum allowed inflight swap IOs"); - MODULE_DESCRIPTION(DM_NAME " driver"); MODULE_AUTHOR("Joe Thornber "); MODULE_LICENSE("GPL"); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index cc558165a71d..703dd52bf4d9 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -316,11 +316,6 @@ struct dm_target { */ bool split_discard_bios:1; - /* - * Set if we need to limit the number of in-flight bios when swapping. - */ - bool limit_swap_bios:1; - /* * Set if inline crypto capabilities from this target's underlying * device(s) can be exposed via the device-mapper device.