f2fs: introduce -o fastboot for reducing booting time only

If a system wants to reduce the booting time as a top priority, now we can
use a mount option, -o fastboot.
With this option, f2fs conducts a little bit slow write_checkpoint, but
it can avoid the node page reads during the next mount time.

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

4 files changed, 16 insertions, 6 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5a9705842f10..d45f3f4d7f93 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -49,6 +49,7 @@
 #define F2FS_MOUNT_INLINE_DENTRY        0x00000200
 #define F2FS_MOUNT_FLUSH_MERGE          0x00000400
 #define F2FS_MOUNT_NOBARRIER            0x00000800
+#define F2FS_MOUNT_FASTBOOT             0x00001000
 
 #define clear_opt(sbi, option)  (sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)    (sbi->mount_opt.opt |= F2FS_MOUNT_##option)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 832bd91922b8..46311e7b388a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -130,6 +130,8 @@ static inline bool need_do_checkpoint(struct inode *inode)
                 need_cp = true;
         else if (F2FS_I(inode)->xattr_ver == cur_cp_version(F2FS_CKPT(sbi)))
                 need_cp = true;
+        else if (test_opt(sbi, FASTBOOT))
+                need_cp = true;
 
         return need_cp;
 }
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 7151d7de7d95..b197a2f2993a 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -695,9 +695,9 @@ int f2fs_gc(struct f2fs_sb_info *sbi)
         int gc_type = BG_GC;
         int nfree = 0;
         int ret = -1;
-        struct cp_control cpc = {
-                .reason = CP_SYNC,
-        };
+        struct cp_control cpc;
+
+        cpc.reason = test_opt(sbi, FASTBOOT) ? CP_UMOUNT : CP_SYNC;
 
         INIT_LIST_HEAD(&ilist);
 gc_more:
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 6c5fc7605109..512ffd8e1624 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -54,6 +54,7 @@ enum {
         Opt_inline_dentry,
         Opt_flush_merge,
         Opt_nobarrier,
+        Opt_fastboot,
         Opt_err,
 };
 
@@ -73,6 +74,7 @@ static match_table_t f2fs_tokens = {
         {Opt_inline_dentry, "inline_dentry"},
         {Opt_flush_merge, "flush_merge"},
         {Opt_nobarrier, "nobarrier"},
+        {Opt_fastboot, "fastboot"},
         {Opt_err, NULL},
 };
 
@@ -351,6 +353,9 @@ static int parse_options(struct super_block *sb, char *options)
                 case Opt_nobarrier:
                         set_opt(sbi, NOBARRIER);
                         break;
+                case Opt_fastboot:
+                        set_opt(sbi, FASTBOOT);
+                        break;
                 default:
                         f2fs_msg(sb, KERN_ERR,
                                 "Unrecognized mount option \"%s\" or missing value",
@@ -479,9 +484,9 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
         trace_f2fs_sync_fs(sb, sync);
 
         if (sync) {
-                struct cp_control cpc = {
-                        .reason = CP_SYNC,
-                };
+                struct cp_control cpc;
+
+                cpc.reason = test_opt(sbi, FASTBOOT) ? CP_UMOUNT : CP_SYNC;
                 mutex_lock(&sbi->gc_mutex);
                 write_checkpoint(sbi, &cpc);
                 mutex_unlock(&sbi->gc_mutex);
@@ -574,6 +579,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
                 seq_puts(seq, ",flush_merge");
         if (test_opt(sbi, NOBARRIER))
                 seq_puts(seq, ",nobarrier");
+        if (test_opt(sbi, FASTBOOT))
+                seq_puts(seq, ",fastboot");
         seq_printf(seq, ",active_logs=%u", sbi->active_logs);
 
         return 0;