Allocate both struct ppl_io_unit and its header_page from a shared
mempool to avoid a possible deadlock. Implement allocate and free
functions for the mempool, remove the second pool for allocating
header_page. The header_pages are now freed with their io_units, not
when the ppl bio completes. Also, use GFP_NOWAIT instead of GFP_ATOMIC
for allocating ppl_io_unit because we can handle failed allocations and
there is no reason to utilize emergency reserves.
Suggested-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx>
---
drivers/md/raid5-ppl.c | 53 +++++++++++++++++++++++++++++++++++---------------
1 file changed, 37 insertions(+), 16 deletions(-)
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 4eb0ebcf9c29..5d25bebf3328 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -102,7 +102,6 @@ struct ppl_conf {
struct kmem_cache *io_kc;
mempool_t *io_pool;
struct bio_set *bs;
- mempool_t *meta_pool;
/* used only for recovery */
int recovered_entries;
@@ -197,25 +196,55 @@ ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
return tx;
}
+static void *ppl_io_pool_alloc(gfp_t gfp_mask, void *pool_data)
+{
+ struct kmem_cache *kc = pool_data;
+ struct ppl_io_unit *io;
+
+ io = kmem_cache_alloc(kc, gfp_mask);
+ if (!io)
+ return NULL;
+
+ io->header_page = alloc_page(gfp_mask);
+ if (!io->header_page) {
+ kmem_cache_free(kc, io);
+ return NULL;
+ }
+
+ return io;
+}
+
+static void ppl_io_pool_free(void *element, void *pool_data)
+{
+ struct kmem_cache *kc = pool_data;
+ struct ppl_io_unit *io = element;
+
+ __free_page(io->header_page);
+ kmem_cache_free(kc, io);
+}
+
static struct ppl_io_unit *ppl_new_iounit(struct ppl_log *log,
struct stripe_head *sh)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct ppl_io_unit *io;
struct ppl_header *pplhdr;
+ struct page *header_page;
- io = mempool_alloc(ppl_conf->io_pool, GFP_ATOMIC);
+ io = mempool_alloc(ppl_conf->io_pool, GFP_NOWAIT);
if (!io)
return NULL;
+ header_page = io->header_page;
memset(io, 0, sizeof(*io));
+ io->header_page = header_page;
+
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
atomic_set(&io->pending_stripes, 0);
bio_init(&io->bio, io->biovec, PPL_IO_INLINE_BVECS);
- io->header_page = mempool_alloc(ppl_conf->meta_pool, GFP_NOIO);
pplhdr = page_address(io->header_page);
clear_page(pplhdr);
memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
@@ -371,8 +400,6 @@ static void ppl_log_endio(struct bio *bio)
if (bio->bi_error)
md_error(ppl_conf->mddev, log->rdev);
- mempool_free(io->header_page, ppl_conf->meta_pool);
-
list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
list_del_init(&sh->log_list);
@@ -1007,7 +1034,6 @@ static void __ppl_exit_log(struct ppl_conf *ppl_conf)
kfree(ppl_conf->child_logs);
- mempool_destroy(ppl_conf->meta_pool);
if (ppl_conf->bs)
bioset_free(ppl_conf->bs);
mempool_destroy(ppl_conf->io_pool);
@@ -1113,25 +1139,20 @@ int ppl_init_log(struct r5conf *conf)
ppl_conf->io_kc = KMEM_CACHE(ppl_io_unit, 0);
if (!ppl_conf->io_kc) {
- ret = -EINVAL;
+ ret = -ENOMEM;
goto err;
}
- ppl_conf->io_pool = mempool_create_slab_pool(conf->raid_disks, ppl_conf->io_kc);
+ ppl_conf->io_pool = mempool_create(conf->raid_disks, ppl_io_pool_alloc,
+ ppl_io_pool_free, ppl_conf->io_kc);
if (!ppl_conf->io_pool) {
- ret = -EINVAL;
+ ret = -ENOMEM;
goto err;
}
ppl_conf->bs = bioset_create(conf->raid_disks, 0);
if (!ppl_conf->bs) {
- ret = -EINVAL;
- goto err;
- }
-
- ppl_conf->meta_pool = mempool_create_page_pool(conf->raid_disks, 0);
- if (!ppl_conf->meta_pool) {
- ret = -EINVAL;
+ ret = -ENOMEM;
goto err;
}
--
2.11.0
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