Re: [PATCH] f2fs: add some sysfs nodes for segment

[Chao Yu]

On 2022/7/12 9:43, Jaegeuk Kim wrote:
> On 07/06, Guowei Du wrote:
> > From: duguowei <duguowei@xxxxxxxxxx>
> >
> > There are two ways to show meta segment information,
> > one is by dump.f2fs, another is by sysfs node. But,
> > sometimes dump needs root privilege,So adding a
> > few sysfs nodes.

If this is used for debug, how about checking /sys/kernel/debug/f2fs/status?

Thanks,

> > The generic permission of node is 0444(S_IRUGO).
> >
> > $ cd /sys/fs/f2fs/DEVICE/...
> > $ ls -l
> > ...
> > -r--r--r-- 1 root root 4096 7月   5 23:21 reserved_segments
> > -r--r--r-- 1 root root 4096 7月   5 23:21 segment_count
> > -r--r--r-- 1 root root 4096 7月   5 23:21 segment_count_ckpt
> > -r--r--r-- 1 root root 4096 7月   5 23:21 segment_count_main
> > -r--r--r-- 1 root root 4096 7月   5 23:21 segment_count_nat
> > -r--r--r-- 1 root root 4096 7月   5 23:21 segment_count_sit
> > -r--r--r-- 1 root root 4096 7月   5 23:21 segment_count_ssa
> > ...
> >
> > $ sudo dump.f2fs -d 1 DEVICE
> > ...
> > Super block
> > segment_count                           [0x      26 : 38]
> > segment_count_ckpt                      [0x       2 : 2]
> > segment_count_sit                       [0x       2 : 2]
> > segment_count_nat                       [0x       2 : 2]
> > segment_count_ssa                       [0x       1 : 1]
> > segment_count_main                      [0x      1f : 31]
> > ...
> > Checkpoint
> > rsvd_segment_count                      [0x       e : 14]
> > ...
> >
> > Signed-off-by: duguowei <duguowei@xxxxxxxxxx>
> > ---
> >   fs/f2fs/sysfs.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 63 insertions(+)
> >
> > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > index 4c50aedd5144..05350bba2c83 100644
> > --- a/fs/f2fs/sysfs.c
> > +++ b/fs/f2fs/sysfs.c
> > @@ -697,6 +697,55 @@ static ssize_t f2fs_sb_feature_show(struct f2fs_attr *a,
> >   	return sprintf(buf, "unsupported\n");
> >   }
> >   
> > +static ssize_t segment_count_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(F2FS_RAW_SUPER(sbi)->segment_count));
> > +}
> > +
> > +static ssize_t segment_count_ckpt_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(F2FS_RAW_SUPER(sbi)->segment_count_ckpt));
> > +}
> > +
> > +static ssize_t segment_count_sit_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(F2FS_RAW_SUPER(sbi)->segment_count_sit));
> > +}
> > +
> > +static ssize_t segment_count_nat_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(F2FS_RAW_SUPER(sbi)->segment_count_nat));
> > +}
> > +
> > +static ssize_t segment_count_ssa_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(F2FS_RAW_SUPER(sbi)->segment_count_ssa));
> > +}
> > +
> > +static ssize_t segment_count_main_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(F2FS_RAW_SUPER(sbi)->segment_count_main));
> > +}
> > +
> > +static ssize_t reserved_segments_show(struct f2fs_attr *a,
> > +		struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +	return sprintf(buf, "%llu\n",
> > +			(unsigned long long)(reserved_segments(sbi)));
> > +}
>
> Can we create a macro to do the above functions?
>
> > +
> >   #define F2FS_SB_FEATURE_RO_ATTR(_name, _feat)			\
> >   static struct f2fs_attr f2fs_attr_sb_##_name = {		\
> >   	.attr = {.name = __stringify(_name), .mode = 0444 },	\
> > @@ -801,6 +850,13 @@ F2FS_GENERAL_RO_ATTR(moved_blocks_background);
> >   F2FS_GENERAL_RO_ATTR(moved_blocks_foreground);
> >   F2FS_GENERAL_RO_ATTR(avg_vblocks);
> >   #endif
> > +F2FS_GENERAL_RO_ATTR(segment_count);
> > +F2FS_GENERAL_RO_ATTR(segment_count_ckpt);
> > +F2FS_GENERAL_RO_ATTR(segment_count_sit);
> > +F2FS_GENERAL_RO_ATTR(segment_count_nat);
> > +F2FS_GENERAL_RO_ATTR(segment_count_ssa);
> > +F2FS_GENERAL_RO_ATTR(segment_count_main);
> > +F2FS_GENERAL_RO_ATTR(reserved_segments);
> >   
> >   #ifdef CONFIG_FS_ENCRYPTION
> >   F2FS_FEATURE_RO_ATTR(encryption);
> > @@ -934,6 +990,13 @@ static struct attribute *f2fs_attrs[] = {
> >   	ATTR_LIST(gc_reclaimed_segments),
> >   	ATTR_LIST(max_fragment_chunk),
> >   	ATTR_LIST(max_fragment_hole),
> > +	ATTR_LIST(segment_count),
> > +	ATTR_LIST(segment_count_ckpt),
> > +	ATTR_LIST(segment_count_sit),
> > +	ATTR_LIST(segment_count_nat),
> > +	ATTR_LIST(segment_count_ssa),
> > +	ATTR_LIST(segment_count_main),
> > +	ATTR_LIST(reserved_segments),
> >   	NULL,
> >   };
> >   ATTRIBUTE_GROUPS(f2fs);
> > --
> > 2.36.1