raid5: allow r5l_io_unit allocations to fail

And propagate the error up the stack so we can add the stripe
to no_stripes_list and retry our log operation later.  This avoids
blocking raid5d due to reclaim, an it allows to get rid of the
deadlock-prone GFP_NOFAIL allocation.

shli: add missing mempool_destroy()

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.com>
This commit is contained in:
Christoph Hellwig 2015-12-21 10:51:02 +11:00 committed by NeilBrown
parent e8deb63810
commit 5036c39020
1 changed files with 57 additions and 10 deletions

View File

@ -75,7 +75,10 @@ struct r5l_log {
struct list_head finished_ios; /* io_units which settle down in log disk */
struct bio flush_bio;
struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */
struct kmem_cache *io_kc;
mempool_t *io_pool;
struct bio_set *bs;
mempool_t *meta_pool;
@ -287,8 +290,11 @@ static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
struct r5l_io_unit *io;
struct r5l_meta_block *block;
/* We can't handle memory allocate failure so far */
io = kmem_cache_zalloc(log->io_kc, GFP_NOIO | __GFP_NOFAIL);
io = mempool_alloc(log->io_pool, GFP_ATOMIC);
if (!io)
return NULL;
memset(io, 0, sizeof(*io));
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
@ -326,8 +332,12 @@ static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
log->current_io->meta_offset + payload_size > PAGE_SIZE)
r5l_submit_current_io(log);
if (!log->current_io)
if (!log->current_io) {
log->current_io = r5l_new_meta(log);
if (!log->current_io)
return -ENOMEM;
}
return 0;
}
@ -372,11 +382,12 @@ static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
r5_reserve_log_entry(log, io);
}
static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
int data_pages, int parity_pages)
{
int i;
int meta_size;
int ret;
struct r5l_io_unit *io;
meta_size =
@ -385,7 +396,10 @@ static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
sizeof(struct r5l_payload_data_parity) +
sizeof(__le32) * parity_pages;
r5l_get_meta(log, meta_size);
ret = r5l_get_meta(log, meta_size);
if (ret)
return ret;
io = log->current_io;
for (i = 0; i < sh->disks; i++) {
@ -415,6 +429,8 @@ static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
list_add_tail(&sh->log_list, &io->stripe_list);
atomic_inc(&io->pending_stripe);
sh->log_io = io;
return 0;
}
static void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
@ -429,6 +445,7 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
int meta_size;
int reserve;
int i;
int ret = 0;
if (!log)
return -EAGAIN;
@ -477,17 +494,22 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
mutex_lock(&log->io_mutex);
/* meta + data */
reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
if (r5l_has_free_space(log, reserve))
r5l_log_stripe(log, sh, data_pages, parity_pages);
else {
if (!r5l_has_free_space(log, reserve)) {
spin_lock(&log->no_space_stripes_lock);
list_add_tail(&sh->log_list, &log->no_space_stripes);
spin_unlock(&log->no_space_stripes_lock);
r5l_wake_reclaim(log, reserve);
} else {
ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
if (ret) {
spin_lock_irq(&log->io_list_lock);
list_add_tail(&sh->log_list, &log->no_mem_stripes);
spin_unlock_irq(&log->io_list_lock);
}
}
mutex_unlock(&log->io_mutex);
mutex_unlock(&log->io_mutex);
return 0;
}
@ -540,6 +562,21 @@ static sector_t r5l_reclaimable_space(struct r5l_log *log)
log->next_checkpoint);
}
static void r5l_run_no_mem_stripe(struct r5l_log *log)
{
struct stripe_head *sh;
assert_spin_locked(&log->io_list_lock);
if (!list_empty(&log->no_mem_stripes)) {
sh = list_first_entry(&log->no_mem_stripes,
struct stripe_head, log_list);
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
}
static bool r5l_complete_finished_ios(struct r5l_log *log)
{
struct r5l_io_unit *io, *next;
@ -556,7 +593,8 @@ static bool r5l_complete_finished_ios(struct r5l_log *log)
log->next_cp_seq = io->seq;
list_del(&io->log_sibling);
kmem_cache_free(log->io_kc, io);
mempool_free(io, log->io_pool);
r5l_run_no_mem_stripe(log);
found = true;
}
@ -1170,6 +1208,10 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
if (!log->io_kc)
goto io_kc;
log->io_pool = mempool_create_slab_pool(R5L_POOL_SIZE, log->io_kc);
if (!log->io_pool)
goto io_pool;
log->bs = bioset_create(R5L_POOL_SIZE, 0);
if (!log->bs)
goto io_bs;
@ -1184,6 +1226,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
goto reclaim_thread;
init_waitqueue_head(&log->iounit_wait);
INIT_LIST_HEAD(&log->no_mem_stripes);
INIT_LIST_HEAD(&log->no_space_stripes);
spin_lock_init(&log->no_space_stripes_lock);
@ -1200,6 +1244,8 @@ reclaim_thread:
out_mempool:
bioset_free(log->bs);
io_bs:
mempool_destroy(log->io_pool);
io_pool:
kmem_cache_destroy(log->io_kc);
io_kc:
kfree(log);
@ -1211,6 +1257,7 @@ void r5l_exit_log(struct r5l_log *log)
md_unregister_thread(&log->reclaim_thread);
mempool_destroy(log->meta_pool);
bioset_free(log->bs);
mempool_destroy(log->io_pool);
kmem_cache_destroy(log->io_kc);
kfree(log);
}