f2fs: use blk_plug in all the possible paths

This patch reverts 19a5f5e2ef37 (f2fs: drop any block plugging),
and adds blk_plug in write paths additionally.

The main reason is that blk_start_plug can be used to wake up from low-power
mode before submitting further bios.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

6 files changed, 29 insertions, 2 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 8ea895389ae4..be1c54b62388 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -265,6 +265,7 @@ static int f2fs_write_meta_pages(struct address_space *mapping,
                                 struct writeback_control *wbc)
 {
         struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+        struct blk_plug plug;
         long diff, written;
 
         /* collect a number of dirty meta pages and write together */
@@ -277,7 +278,9 @@ static int f2fs_write_meta_pages(struct address_space *mapping,
         /* if mounting is failed, skip writing node pages */
         mutex_lock(&sbi->cp_mutex);
         diff = nr_pages_to_write(sbi, META, wbc);
+        blk_start_plug(&plug);
         written = sync_meta_pages(sbi, META, wbc->nr_to_write);
+        blk_finish_plug(&plug);
         mutex_unlock(&sbi->cp_mutex);
         wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);
         return 0;
@@ -899,8 +902,11 @@ static int block_operations(struct f2fs_sb_info *sbi)
                 .nr_to_write = LONG_MAX,
                 .for_reclaim = 0,
         };
+        struct blk_plug plug;
         int err = 0;
 
+        blk_start_plug(&plug);
+
 retry_flush_dents:
         f2fs_lock_all(sbi);
         /* write all the dirty dentry pages */
@@ -937,6 +943,7 @@ retry_flush_nodes:
                 goto retry_flush_nodes;
         }
 out:
+        blk_finish_plug(&plug);
         return err;
 }
 
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index adfe47b21991..87a458fb8afe 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1438,6 +1438,7 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 {
         struct inode *inode = mapping->host;
         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+        struct blk_plug plug;
         int ret;
 
         /* deal with chardevs and other special file */
@@ -1463,7 +1464,9 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 
         trace_f2fs_writepages(mapping->host, wbc, DATA);
 
+        blk_start_plug(&plug);
         ret = f2fs_write_cache_pages(mapping, wbc);
+        blk_finish_plug(&plug);
         /*
          * if some pages were truncated, we cannot guarantee its mapping->host
          * to detect pending bios.
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 72e52cd15b60..47f1f5e36d1c 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2102,6 +2102,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file);
+        struct blk_plug plug;
         ssize_t ret;
 
         if (f2fs_encrypted_inode(inode) &&
@@ -2113,8 +2114,11 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
         ret = generic_write_checks(iocb, from);
         if (ret > 0) {
                 ret = f2fs_preallocate_blocks(iocb, from);
-                if (!ret)
+                if (!ret) {
+                        blk_start_plug(&plug);
                         ret = __generic_file_write_iter(iocb, from);
+                        blk_finish_plug(&plug);
+                }
         }
         inode_unlock(inode);
 
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 5c8acf754513..de6c41c32c62 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -808,6 +808,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
 {
         struct page *sum_page;
         struct f2fs_summary_block *sum;
+        struct blk_plug plug;
         unsigned int segno = start_segno;
         unsigned int end_segno = start_segno + sbi->segs_per_sec;
         int seg_freed = 0;
@@ -825,6 +826,8 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
                 unlock_page(sum_page);
         }
 
+        blk_start_plug(&plug);
+
         for (segno = start_segno; segno < end_segno; segno++) {
 
                 if (get_valid_blocks(sbi, segno, 1) == 0)
@@ -862,6 +865,8 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
                 f2fs_submit_merged_bio(sbi,
                                 (type == SUM_TYPE_NODE) ? NODE : DATA, WRITE);
 
+        blk_finish_plug(&plug);
+
         if (gc_type == FG_GC) {
                 while (start_segno < end_segno)
                         if (get_valid_blocks(sbi, start_segno++, 1) == 0)
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index d78f61d647c0..79a93c6e632f 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1618,6 +1618,7 @@ static int f2fs_write_node_pages(struct address_space *mapping,
                             struct writeback_control *wbc)
 {
         struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+        struct blk_plug plug;
         long diff;
 
         /* balancing f2fs's metadata in background */
@@ -1631,7 +1632,9 @@ static int f2fs_write_node_pages(struct address_space *mapping,
 
         diff = nr_pages_to_write(sbi, NODE, wbc);
         wbc->sync_mode = WB_SYNC_NONE;
+        blk_start_plug(&plug);
         sync_node_pages(sbi, wbc);
+        blk_finish_plug(&plug);
         wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
         return 0;
 
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e87aa058f57a..d45e6bbf8493 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -381,8 +381,13 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
                         excess_prefree_segs(sbi) ||
                         excess_dirty_nats(sbi) ||
                         (is_idle(sbi) && f2fs_time_over(sbi, CP_TIME))) {
-                if (test_opt(sbi, DATA_FLUSH))
+                if (test_opt(sbi, DATA_FLUSH)) {
+                        struct blk_plug plug;
+
+                        blk_start_plug(&plug);
                         sync_dirty_inodes(sbi, FILE_INODE);
+                        blk_finish_plug(&plug);
+                }
                 f2fs_sync_fs(sbi->sb, true);
                 stat_inc_bg_cp_count(sbi->stat_info);
         }