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? 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, > >