f2fs: cleanup waiting routine for writeback pages in cp

use genernal method supported by kernel

 o changes from v1
   If any waiter exists at end io, wake up it.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

4 files changed, 21 insertions, 12 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index d430157ffe60..5716e5eb4e8e 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -634,6 +634,21 @@ static void unblock_operations(struct f2fs_sb_info *sbi)
         f2fs_unlock_all(sbi);
 }
 
+static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
+{
+        DEFINE_WAIT(wait);
+
+        for (;;) {
+                prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
+
+                if (!get_pages(sbi, F2FS_WRITEBACK))
+                        break;
+
+                io_schedule();
+        }
+        finish_wait(&sbi->cp_wait, &wait);
+}
+
 static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
 {
         struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
@@ -743,15 +758,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
         f2fs_put_page(cp_page, 1);
 
         /* wait for previous submitted node/meta pages writeback */
-        sbi->cp_task = current;
-        while (get_pages(sbi, F2FS_WRITEBACK)) {
-                set_current_state(TASK_UNINTERRUPTIBLE);
-                if (!get_pages(sbi, F2FS_WRITEBACK))
-                        break;
-                io_schedule();
-        }
-        __set_current_state(TASK_RUNNING);
-        sbi->cp_task = NULL;
+        wait_on_all_pages_writeback(sbi);
 
         filemap_fdatawait_range(sbi->node_inode->i_mapping, 0, LONG_MAX);
         filemap_fdatawait_range(sbi->meta_inode->i_mapping, 0, LONG_MAX);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 625eb4befad4..89dc7508faf2 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -372,7 +372,7 @@ struct f2fs_sb_info {
         struct mutex writepages;                /* mutex for writepages() */
         bool por_doing;                         /* recovery is doing or not */
         bool on_build_free_nids;                /* build_free_nids is doing */
-        struct task_struct *cp_task;            /* checkpoint task */
+        wait_queue_head_t cp_wait;
 
         /* for orphan inode management */
         struct list_head orphan_inode_list;     /* orphan inode list */
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index ff363e686b7e..86dc28949192 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -592,8 +592,9 @@ static void f2fs_end_io_write(struct bio *bio, int err)
         if (p->is_sync)
                 complete(p->wait);
 
-        if (!get_pages(p->sbi, F2FS_WRITEBACK) && p->sbi->cp_task)
-                wake_up_process(p->sbi->cp_task);
+        if (!get_pages(p->sbi, F2FS_WRITEBACK) &&
+                        !list_empty(&p->sbi->cp_wait.task_list))
+                wake_up(&p->sbi->cp_wait);
 
         kfree(p);
         bio_put(bio);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index e42351cbe166..00e79df5a34f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -876,6 +876,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
         spin_lock_init(&sbi->stat_lock);
         init_rwsem(&sbi->bio_sem);
         init_rwsem(&sbi->cp_rwsem);
+        init_waitqueue_head(&sbi->cp_wait);
         init_sb_info(sbi);
 
         /* get an inode for meta space */