f2fs: add the flush_merge handle in the remount flow

Add the *remount* handle of flush_merge option, so that the users
can enable flush_merge in the runtime, such as the underlying device
handles the cache_flush command relatively slowly.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d3180f8..55152de 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1177,6 +1177,7 @@ void destroy_node_manager_caches(void);
  */
 void f2fs_balance_fs(struct f2fs_sb_info *);
 void f2fs_balance_fs_bg(struct f2fs_sb_info *);
+int issue_flush_thread(void *);
 int f2fs_issue_flush(struct f2fs_sb_info *);
 void invalidate_blocks(struct f2fs_sb_info *, block_t);
 void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9993f94..f6816e1 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -197,7 +197,7 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
                f2fs_sync_fs(sbi->sb, true);
 }
 
-static int issue_flush_thread(void *data)
+int issue_flush_thread(void *data)
 {
        struct f2fs_sb_info *sbi = data;
        struct f2fs_sm_info *sm_i = SM_I(sbi);

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 5e20d2a..bea642a 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -594,6 +594,8 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
        struct f2fs_sb_info *sbi = F2FS_SB(sb);
        struct f2fs_mount_info org_mount_opt;
        int err, active_logs;
+       bool need_restart_gc = false;
+       bool need_stop_gc = false;
 
        sync_filesystem(sb);
 
@@ -611,7 +613,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 
        /*
         * Previous and new state of filesystem is RO,
-        * so no point in checking GC conditions.
+        * so skip checking GC and FLUSH_MERGE conditions.
         */
        if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
                goto skip;
@@ -625,18 +627,57 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
                if (sbi->gc_thread) {
                        stop_gc_thread(sbi);
                        f2fs_sync_fs(sb, 1);
+                       need_restart_gc = true;
                }
        } else if (test_opt(sbi, BG_GC) && !sbi->gc_thread) {
                err = start_gc_thread(sbi);
                if (err)
                        goto restore_opts;
+               need_stop_gc = true;
+       }
+
+       /*
+        * We stop issue flush thread if FS is mounted as RO
+        * or if flush_merge is not passed in mount option.
+        */
+       if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
+               struct f2fs_sm_info *sm_info = sbi->sm_info;
+
+               if (sm_info->f2fs_issue_flush)
+                       kthread_stop(sm_info->f2fs_issue_flush);
+               sm_info->issue_list = sm_info->dispatch_list = NULL;
+               sm_info->f2fs_issue_flush = NULL;
+       } else if (test_opt(sbi, FLUSH_MERGE)) {
+               struct f2fs_sm_info *sm_info = sbi->sm_info;
+
+               if (!sm_info->f2fs_issue_flush) {
+                       dev_t dev = sbi->sb->s_bdev->bd_dev;
+
+                       spin_lock_init(&sm_info->issue_lock);
+                       init_waitqueue_head(&sm_info->flush_wait_queue);
+                       sm_info->f2fs_issue_flush =
+                               kthread_run(issue_flush_thread, sbi,
+                               "f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
+                       if (IS_ERR(sm_info->f2fs_issue_flush)) {
+                               err = PTR_ERR(sm_info->f2fs_issue_flush);
+                               sm_info->f2fs_issue_flush = NULL;
+                               goto restore_gc;
+                       }
+               }
        }
 skip:
        /* Update the POSIXACL Flag */
         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
                (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
        return 0;
-
+restore_gc:
+       if (need_restart_gc) {
+               if (start_gc_thread(sbi))
+                       f2fs_msg(sbi->sb, KERN_WARNING,
+                               "background gc thread is stop");
+       } else if (need_stop_gc) {
+               stop_gc_thread(sbi);
+       }
 restore_opts:
        sbi->mount_opt = org_mount_opt;
        sbi->active_logs = active_logs;