f2fs: handle failed bio allocation

As the below comment of bio_alloc_bioset, f2fs can allocate multiple bios at the
same time. So, we can't guarantee that bio is allocated all the time.

"
 *   When @bs is not NULL, if %__GFP_WAIT is set then bio_alloc will always be
 *   able to allocate a bio. This is due to the mempool guarantees. To make this
 *   work, callers must never allocate more than 1 bio at a time from this pool.
 *   Callers that need to allocate more than 1 bio must always submit the
 *   previously allocated bio for IO before attempting to allocate a new one.
 *   Failure to do so can cause deadlocks under memory pressure.
"

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2015-08-14 11:43:56 -07:00
parent a6db67f06f
commit 740432f835
3 changed files with 28 additions and 5 deletions

View File

@ -90,8 +90,7 @@ static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
{
struct bio *bio;
/* No failure on bio allocation */
bio = bio_alloc(GFP_NOIO, npages);
bio = f2fs_bio_alloc(npages);
bio->bi_bdev = sbi->sb->s_bdev;
bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);

View File

@ -19,6 +19,7 @@
#include <linux/magic.h>
#include <linux/kobject.h>
#include <linux/sched.h>
#include <linux/bio.h>
#ifdef CONFIG_F2FS_CHECK_FS
#define f2fs_bug_on(sbi, condition) BUG_ON(condition)
@ -1253,6 +1254,20 @@ static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
return entry;
}
static inline struct bio *f2fs_bio_alloc(int npages)
{
struct bio *bio;
/* No failure on bio allocation */
retry:
bio = bio_alloc(GFP_NOIO, npages);
if (!bio) {
cond_resched();
goto retry;
}
return bio;
}
static inline void f2fs_radix_tree_insert(struct radix_tree_root *root,
unsigned long index, void *item)
{

View File

@ -330,10 +330,12 @@ static int issue_flush_thread(void *data)
return 0;
if (!llist_empty(&fcc->issue_list)) {
struct bio *bio = bio_alloc(GFP_NOIO, 0);
struct bio *bio;
struct flush_cmd *cmd, *next;
int ret;
bio = f2fs_bio_alloc(0);
fcc->dispatch_list = llist_del_all(&fcc->issue_list);
fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
@ -365,8 +367,15 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
if (test_opt(sbi, NOBARRIER))
return 0;
if (!test_opt(sbi, FLUSH_MERGE))
return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
if (!test_opt(sbi, FLUSH_MERGE)) {
struct bio *bio = f2fs_bio_alloc(0);
int ret;
bio->bi_bdev = sbi->sb->s_bdev;
ret = submit_bio_wait(WRITE_FLUSH, bio);
bio_put(bio);
return ret;
}
init_completion(&cmd.wait);