f2fs: fix error path of f2fs_remount()

In error path of f2fs_remount(), it missed to restart/stop kernel thread
or enable/disable checkpoint, then mount option status may not be
consistent with real condition of filesystem, so let's reorder remount
flow a bit as below and do recovery correctly in error path:

1) handle gc thread
2) handle ckpt thread
3) handle flush thread
4) handle checkpoint disabling

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

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 721dc64..b482816 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1927,8 +1927,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
        struct f2fs_mount_info org_mount_opt;
        unsigned long old_sb_flags;
        int err;
-       bool need_restart_gc = false;
-       bool need_stop_gc = false;
+       bool need_restart_gc = false, need_stop_gc = false;
+       bool need_restart_ckpt = false, need_stop_ckpt = false;
+       bool need_restart_flush = false, need_stop_flush = false;
        bool no_extent_cache = !test_opt(sbi, EXTENT_CACHE);
        bool disable_checkpoint = test_opt(sbi, DISABLE_CHECKPOINT);
        bool no_io_align = !F2FS_IO_ALIGNED(sbi);
@@ -2059,19 +2060,10 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
                clear_sbi_flag(sbi, SBI_IS_CLOSE);
        }
 
-       if (checkpoint_changed) {
-               if (test_opt(sbi, DISABLE_CHECKPOINT)) {
-                       err = f2fs_disable_checkpoint(sbi);
-                       if (err)
-                               goto restore_gc;
-               } else {
-                       f2fs_enable_checkpoint(sbi);
-               }
-       }
-
        if ((*flags & SB_RDONLY) || test_opt(sbi, DISABLE_CHECKPOINT) ||
                        !test_opt(sbi, MERGE_CHECKPOINT)) {
                f2fs_stop_ckpt_thread(sbi);
+               need_restart_ckpt = true;
        } else {
                err = f2fs_start_ckpt_thread(sbi);
                if (err) {
@@ -2080,6 +2072,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
                            err);
                        goto restore_gc;
                }
+               need_stop_ckpt = true;
        }
 
        /*
@@ -2089,11 +2082,24 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
        if ((*flags & SB_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
                clear_opt(sbi, FLUSH_MERGE);
                f2fs_destroy_flush_cmd_control(sbi, false);
+               need_restart_flush = true;
        } else {
                err = f2fs_create_flush_cmd_control(sbi);
                if (err)
-                       goto restore_gc;
+                       goto restore_ckpt;
+               need_stop_flush = true;
        }
+
+       if (checkpoint_changed) {
+               if (test_opt(sbi, DISABLE_CHECKPOINT)) {
+                       err = f2fs_disable_checkpoint(sbi);
+                       if (err)
+                               goto restore_flush;
+               } else {
+                       f2fs_enable_checkpoint(sbi);
+               }
+       }
+
 skip:
 #ifdef CONFIG_QUOTA
        /* Release old quota file names */
@@ -2108,6 +2114,21 @@ skip:
        adjust_unusable_cap_perc(sbi);
        *flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
        return 0;
+restore_flush:
+       if (need_restart_flush) {
+               if (f2fs_create_flush_cmd_control(sbi))
+                       f2fs_warn(sbi, "background flush thread has stopped");
+       } else if (need_stop_flush) {
+               clear_opt(sbi, FLUSH_MERGE);
+               f2fs_destroy_flush_cmd_control(sbi, false);
+       }
+restore_ckpt:
+       if (need_restart_ckpt) {
+               if (f2fs_start_ckpt_thread(sbi))
+                       f2fs_warn(sbi, "background ckpt thread has stopped");
+       } else if (need_stop_ckpt) {
+               f2fs_stop_ckpt_thread(sbi);
+       }
 restore_gc:
        if (need_restart_gc) {
                if (f2fs_start_gc_thread(sbi))