f2fs: support bio allocation error injection

This patch adds to support bio allocation error injection to simulate
out-of-memory test scenario.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -173,7 +173,7 @@ static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
 {
 	struct bio *bio;
 
-	bio = f2fs_bio_alloc(npages);
+	bio = f2fs_bio_alloc(sbi, npages, true);
 
 	f2fs_target_device(sbi, blk_addr, bio);
 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
@@ -473,7 +473,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
 		f2fs_wait_on_block_writeback(sbi, blkaddr);
 	}
 
-	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
+	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
 	if (!bio) {
 		if (ctx)
 			fscrypt_release_ctx(ctx);

fs/f2fs/f2fs.h

@@ -47,6 +47,7 @@ enum {
 	FAULT_KMALLOC,
 	FAULT_PAGE_ALLOC,
 	FAULT_PAGE_GET,
+	FAULT_ALLOC_BIO,
 	FAULT_ALLOC_NID,
 	FAULT_ORPHAN,
 	FAULT_BLOCK,
@@ -1898,15 +1899,25 @@ static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
 	return entry;
 }
 
-static inline struct bio *f2fs_bio_alloc(int npages)
+static inline struct bio *f2fs_bio_alloc(struct f2fs_sb_info *sbi,
+						int npages, bool no_fail)
 {
 	struct bio *bio;
 
-	/* No failure on bio allocation */
-	bio = bio_alloc(GFP_NOIO, npages);
-	if (!bio)
-		bio = bio_alloc(GFP_NOIO | __GFP_NOFAIL, npages);
-	return 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;
+	}
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_ALLOC_BIO)) {
+		f2fs_show_injection_info(FAULT_ALLOC_BIO);
+		return NULL;
+	}
+#endif
+	return bio_alloc(GFP_KERNEL, npages);
 }
 
 static inline void f2fs_radix_tree_insert(struct radix_tree_root *root,

fs/f2fs/segment.c

@@ -511,7 +511,7 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
 static int __submit_flush_wait(struct f2fs_sb_info *sbi,
 				struct block_device *bdev)
 {
-	struct bio *bio = f2fs_bio_alloc(0);
+	struct bio *bio = f2fs_bio_alloc(sbi, 0, true);
 	int ret;
 
 	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;

fs/f2fs/super.c

@@ -45,6 +45,7 @@ char *fault_name[FAULT_MAX] = {
 	[FAULT_KMALLOC]		= "kmalloc",
 	[FAULT_PAGE_ALLOC]	= "page alloc",
 	[FAULT_PAGE_GET]	= "page get",
+	[FAULT_ALLOC_BIO]	= "alloc bio",
 	[FAULT_ALLOC_NID]	= "alloc nid",
 	[FAULT_ORPHAN]		= "orphan",
 	[FAULT_BLOCK]		= "no more block",