f2fs: introduce private bioset

In low memory scenario, we can allocate multiple bios without
submitting any of them.

- f2fs_write_checkpoint()
 - block_operations()
  - f2fs_sync_node_pages()
   step 1) flush cold nodes, allocate new bio from mempool
   - bio_alloc()
    - mempool_alloc()
   step 2) flush hot nodes, allocate a bio from mempool
   - bio_alloc()
    - mempool_alloc()
   step 3) flush warm nodes, be stuck in below call path
   - bio_alloc()
    - mempool_alloc()
     - loop to wait mempool element release, as we only
       reserved memory for two bio allocation, however above
       allocated two bios may never be submitted.

So we need avoid using default bioset, in this patch we introduce a
private bioset, in where we enlarg mempool element count to total
number of log header, so that we can make sure we have enough
backuped memory pool in scenario of allocating/holding multiple
bios.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 3 insertions, 20 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 33c57627b649..dbc20d33d0e1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2221,26 +2221,6 @@ static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
 	return entry;
 }
 
-static inline struct bio *f2fs_bio_alloc(struct f2fs_sb_info *sbi,
-						int npages, bool no_fail)
-{
-	struct bio *bio;
-
-	if (no_fail) {
-		/* No failure on bio allocation */
-		bio = bio_alloc(GFP_NOIO, npages);
-		if (!bio)
-			bio = bio_alloc(GFP_NOIO | __GFP_NOFAIL, npages);
-		return bio;
-	}
-	if (time_to_inject(sbi, FAULT_ALLOC_BIO)) {
-		f2fs_show_injection_info(sbi, FAULT_ALLOC_BIO);
-		return NULL;
-	}
-
-	return bio_alloc(GFP_KERNEL, npages);
-}
-
 static inline bool is_idle(struct f2fs_sb_info *sbi, int type)
 {
 	if (sbi->gc_mode == GC_URGENT)
@@ -3206,6 +3186,9 @@ void f2fs_destroy_checkpoint_caches(void);
 /*
  * data.c
  */
+int __init f2fs_init_bioset(void);
+void f2fs_destroy_bioset(void);
+struct bio *f2fs_bio_alloc(struct f2fs_sb_info *sbi, int npages, bool no_fail);
 int f2fs_init_post_read_processing(void);
 void f2fs_destroy_post_read_processing(void);
 int f2fs_init_bio_entry_cache(void);