f2fs: cache global IPU bio

In commit 8648de2c581e ("f2fs: add bio cache for IPU"), we added
f2fs_submit_ipu_bio() in __write_data_page() as below:

__write_data_page()

	if (!S_ISDIR(inode->i_mode) && !IS_NOQUOTA(inode)) {
		f2fs_submit_ipu_bio(sbi, bio, page);
		....
	}

in order to avoid below deadlock:

Thread A				Thread B
- __write_data_page (inode x, page y)
 - f2fs_do_write_data_page
  - set_page_writeback        ---- set writeback flag in page y
  - f2fs_inplace_write_data
 - f2fs_balance_fs
					 - lock gc_mutex
 - lock gc_mutex
					  - f2fs_gc
					   - do_garbage_collect
					    - gc_data_segment
					     - move_data_page
					      - f2fs_wait_on_page_writeback
					       - wait_on_page_writeback  --- wait writeback of page y

However, the bio submission breaks the merge of IPU IOs.

So in this patch let's add a global bio cache for merged IPU pages,
then f2fs_wait_on_page_writeback() is able to submit bio if a
writebacked page is cached in global bio cache.

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

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f078cd20dab8..ca342f4c7db1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1068,6 +1068,11 @@ struct f2fs_io_info {
 	unsigned char version;		/* version of the node */
 };
 
+struct bio_entry {
+	struct bio *bio;
+	struct list_head list;
+};
+
 #define is_read_io(rw) ((rw) == READ)
 struct f2fs_bio_info {
 	struct f2fs_sb_info *sbi;	/* f2fs superblock */
@@ -1077,6 +1082,8 @@ struct f2fs_bio_info {
 	struct rw_semaphore io_rwsem;	/* blocking op for bio */
 	spinlock_t io_lock;		/* serialize DATA/NODE IOs */
 	struct list_head io_list;	/* track fios */
+	struct list_head bio_list;	/* bio entry list head */
+	struct rw_semaphore bio_list_lock;	/* lock to protect bio entry list */
 };
 
 #define FDEV(i)				(sbi->devs[i])
@@ -3195,10 +3202,14 @@ void f2fs_destroy_checkpoint_caches(void);
  */
 int f2fs_init_post_read_processing(void);
 void f2fs_destroy_post_read_processing(void);
+int f2fs_init_bio_entry_cache(void);
+void f2fs_destroy_bio_entry_cache(void);
 void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type);
 void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
 				struct inode *inode, struct page *page,
 				nid_t ino, enum page_type type);
+void f2fs_submit_merged_ipu_write(struct f2fs_sb_info *sbi,
+					struct bio **bio, struct page *page);
 void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi);
 int f2fs_submit_page_bio(struct f2fs_io_info *fio);
 int f2fs_merge_page_bio(struct f2fs_io_info *fio);