On 2021/2/2 17:44, Daeho Jeong wrote:
When we remount it without the "checkpoint_merge" option, shouldn't we
need to clear "MERGE_CHECKPOINT" again?
This is actually what I intended, but I was wrong. Actually, I found this.

When we remount the filesystem, the previous mount option is passed
through the "data" argument in the below.
f2fs_remount(struct super_block *sb, int *flags, char *data)

If we don't provide the "nocheckpoint_merge" option, how can we turn
off the "checkpoint_merge" option which is turned on in the previous
mount?

We can use "mount -o remount /dev/xxx /mnt" to disable checkpoint_merge,
since that command won't pass old mount options to remount?

Quoted from man mount:

              mount -o remount,rw /dev/foo /dir

              After  this  call  all  old  mount options are replaced and 
arbitrary stuff from fstab (or mtab) is ignored, except the loop= option which 
is internally generated and maintained by the
              mount command.

              mount -o remount,rw  /dir

              After this call mount reads fstab and merges these options with 
the options from the command line (-o). If no mountpoint found in fstab than 
remount with unspecified source is allowed.

Thanks,


2021년 2월 2일 (화) 오후 6:28, Chao Yu <yuch...@huawei.com>님이 작성:

On 2021/2/2 17:23, Daeho Jeong wrote:
From: Daeho Jeong <daehoje...@google.com>

As checkpoint=merge comes in, mount option setting related to checkpoint
had been mixed up and it became hard to understand. So, I separated
this option from "checkpoint=" and made another mount option
"checkpoint_merge" for this.

Signed-off-by: Daeho Jeong <daehoje...@google.com>
---
v2: renamed "checkpoint=merge" to "checkpoint_merge"
v3: removed "nocheckpoint_merge" option
---
   Documentation/filesystems/f2fs.rst |  6 +++---
   fs/f2fs/super.c                    | 21 +++++++++------------
   2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index d0ead45dc706..475994ed8b15 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]      Set to "disable" to turn off 
checkpointing. Set to "enabl
                        hide up to all remaining free space. The actual space 
that
                        would be unusable can be viewed at 
/sys/fs/f2fs/<disk>/unusable
                        This space is reclaimed once checkpoint=enable.
-                      Here is another option "merge", which creates a kernel 
daemon
-                      and makes it to merge concurrent checkpoint requests as 
much
-                      as possible to eliminate redundant checkpoint issues. 
Plus,
+checkpoint_merge      When checkpoint is enabled, this can be used to create a 
kernel
+                      daemon and make it to merge concurrent checkpoint 
requests as
+                      much as possible to eliminate redundant checkpoint 
issues. Plus,
                        we can eliminate the sluggish issue caused by slow 
checkpoint
                        operation when the checkpoint is done in a process 
context in
                        a cgroup having low i/o budget and cpu shares. To make 
this
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56696f6cfa86..b60dcef7f9d0 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -215,7 +215,7 @@ static match_table_t f2fs_tokens = {
       {Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
       {Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
       {Opt_checkpoint_enable, "checkpoint=enable"},
-     {Opt_checkpoint_merge, "checkpoint=merge"},
+     {Opt_checkpoint_merge, "checkpoint_merge"},
       {Opt_compress_algorithm, "compress_algorithm=%s"},
       {Opt_compress_log_size, "compress_log_size=%u"},
       {Opt_compress_extension, "compress_extension=%s"},
@@ -1142,12 +1142,6 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
               return -EINVAL;
       }

-     if (test_opt(sbi, DISABLE_CHECKPOINT) &&
-                     test_opt(sbi, MERGE_CHECKPOINT)) {
-             f2fs_err(sbi, "checkpoint=merge cannot be used with 
checkpoint=disable\n");
-             return -EINVAL;
-     }
-
       /* Not pass down write hints if the number of active logs is lesser
        * than NR_CURSEG_PERSIST_TYPE.
        */
@@ -1782,7 +1776,7 @@ static int f2fs_show_options(struct seq_file *seq, struct 
dentry *root)
               seq_printf(seq, ",checkpoint=disable:%u",
                               F2FS_OPTION(sbi).unusable_cap);
       if (test_opt(sbi, MERGE_CHECKPOINT))
-             seq_puts(seq, ",checkpoint=merge");
+             seq_puts(seq, ",checkpoint_merge");
       if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
               seq_printf(seq, ",fsync_mode=%s", "posix");
       else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
@@ -1827,6 +1821,7 @@ static void default_options(struct f2fs_sb_info *sbi)
       sbi->sb->s_flags |= SB_LAZYTIME;
       set_opt(sbi, FLUSH_MERGE);
       set_opt(sbi, DISCARD);
+     clear_opt(sbi, MERGE_CHECKPOINT);

It's not needed here?

Thanks,

       if (f2fs_sb_has_blkzoned(sbi))
               F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS;
       else
@@ -2066,9 +2061,8 @@ static int f2fs_remount(struct super_block *sb, int 
*flags, char *data)
               }
       }

-     if (!test_opt(sbi, MERGE_CHECKPOINT)) {
-             f2fs_stop_ckpt_thread(sbi);
-     } else {
+     if (!test_opt(sbi, DISABLE_CHECKPOINT) &&
+                     test_opt(sbi, MERGE_CHECKPOINT)) {
               err = f2fs_start_ckpt_thread(sbi);
               if (err) {
                       f2fs_err(sbi,
@@ -2076,6 +2070,8 @@ static int f2fs_remount(struct super_block *sb, int 
*flags, char *data)
                           err);
                       goto restore_gc;
               }
+     } else {
+             f2fs_stop_ckpt_thread(sbi);
       }

       /*
@@ -3831,7 +3827,8 @@ static int f2fs_fill_super(struct super_block *sb, void 
*data, int silent)

       /* setup checkpoint request control and start checkpoint issue thread */
       f2fs_init_ckpt_req_control(sbi);
-     if (test_opt(sbi, MERGE_CHECKPOINT)) {
+     if (!test_opt(sbi, DISABLE_CHECKPOINT) &&
+                     test_opt(sbi, MERGE_CHECKPOINT)) {
               err = f2fs_start_ckpt_thread(sbi);
               if (err) {
                       f2fs_err(sbi,

.

Reply via email to