| Message ID | 20210310090833.105015-2-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: support read-write for subpage metadata | expand |
On 10/03/2021 17:08, Qu Wenruo wrote: > Add extra sysfs interface features/supported_ro_sectorsize and > features/supported_rw_sectorsize to indicate subpage support. > > Currently for supported_rw_sectorsize all architectures only have their > PAGE_SIZE listed. > > While for supported_ro_sectorsize, for systems with 64K page size, 4K > sectorsize is also supported. > > This new sysfs interface would help mkfs.btrfs to do more accurate > warning. > > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- Changes looks good. Nit below... And maybe it is a good idea to wait for other comments before reroll. > fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > index 6eb1c50fa98c..3ef419899472 100644 > --- a/fs/btrfs/sysfs.c > +++ b/fs/btrfs/sysfs.c > @@ -360,11 +360,45 @@ static ssize_t supported_rescue_options_show(struct kobject *kobj, > BTRFS_ATTR(static_feature, supported_rescue_options, > supported_rescue_options_show); > > +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, > + struct kobj_attribute *a, > + char *buf) > +{ > + ssize_t ret = 0; > + int i = 0; Drop variable i, as ret can be used instead of 'i'. > + > + /* For 64K page size, 4K sector size is supported */ > + if (PAGE_SIZE == SZ_64K) { > + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); > + i++; > + } > + /* Other than above subpage, only support PAGE_SIZE as sectorsize yet */ > + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", > + (i ? " " : ""), PAGE_SIZE); ^ret > + return ret; > +} > +BTRFS_ATTR(static_feature, supported_ro_sectorsize, > + supported_ro_sectorsize_show); > + > +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, > + struct kobj_attribute *a, > + char *buf) > +{ > + ssize_t ret = 0; > + > + /* Only PAGE_SIZE as sectorsize is supported */ > + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); > + return ret; > +} > +BTRFS_ATTR(static_feature, supported_rw_sectorsize, > + supported_rw_sectorsize_show); Why not merge supported_ro_sectorsize and supported_rw_sectorsize and show both in two lines... For example: cat supported_sectorsizes ro: 4096 65536 rw: 65536 > static struct attribute *btrfs_supported_static_feature_attrs[] = { > BTRFS_ATTR_PTR(static_feature, rmdir_subvol), > BTRFS_ATTR_PTR(static_feature, supported_checksums), > BTRFS_ATTR_PTR(static_feature, send_stream_version), > BTRFS_ATTR_PTR(static_feature, supported_rescue_options), > + BTRFS_ATTR_PTR(static_feature, supported_ro_sectorsize), > + BTRFS_ATTR_PTR(static_feature, supported_rw_sectorsize), > NULL > }; > >
On 2021/3/15 下午7:59, Anand Jain wrote: > On 10/03/2021 17:08, Qu Wenruo wrote: >> Add extra sysfs interface features/supported_ro_sectorsize and >> features/supported_rw_sectorsize to indicate subpage support. >> >> Currently for supported_rw_sectorsize all architectures only have their >> PAGE_SIZE listed. >> >> While for supported_ro_sectorsize, for systems with 64K page size, 4K >> sectorsize is also supported. >> >> This new sysfs interface would help mkfs.btrfs to do more accurate >> warning. >> >> Signed-off-by: Qu Wenruo <wqu@suse.com> >> --- > > Changes looks good. Nit below... > And maybe it is a good idea to wait for other comments before reroll. > >> fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ >> 1 file changed, 34 insertions(+) >> >> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c >> index 6eb1c50fa98c..3ef419899472 100644 >> --- a/fs/btrfs/sysfs.c >> +++ b/fs/btrfs/sysfs.c >> @@ -360,11 +360,45 @@ static ssize_t >> supported_rescue_options_show(struct kobject *kobj, >> BTRFS_ATTR(static_feature, supported_rescue_options, >> supported_rescue_options_show); >> +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, >> + struct kobj_attribute *a, >> + char *buf) >> +{ >> + ssize_t ret = 0; >> + int i = 0; > > Drop variable i, as ret can be used instead of 'i'. > >> + >> + /* For 64K page size, 4K sector size is supported */ >> + if (PAGE_SIZE == SZ_64K) { >> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); >> + i++; >> + } >> + /* Other than above subpage, only support PAGE_SIZE as sectorsize >> yet */ >> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", > >> + (i ? " " : ""), PAGE_SIZE); > ^ret > >> + return ret; >> +} >> +BTRFS_ATTR(static_feature, supported_ro_sectorsize, >> + supported_ro_sectorsize_show); >> + >> +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, >> + struct kobj_attribute *a, >> + char *buf) >> +{ >> + ssize_t ret = 0; >> + >> + /* Only PAGE_SIZE as sectorsize is supported */ >> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); >> + return ret; >> +} >> +BTRFS_ATTR(static_feature, supported_rw_sectorsize, >> + supported_rw_sectorsize_show); > > Why not merge supported_ro_sectorsize and supported_rw_sectorsize > and show both in two lines... > For example: > cat supported_sectorsizes > ro: 4096 65536 > rw: 65536 If merged, btrfs-progs needs to do line number check before doing string matching. Although I doubt the usefulness for supported_ro_sectorsize, as the window for RO support without RW support should not be that large. (Current RW passes most generic test cases, and the remaining failures are very limited) Thus I can merged them into supported_sectorsize, and only report sectorsize we can do RW as supported. Thanks, Qu > > > >> static struct attribute *btrfs_supported_static_feature_attrs[] = { >> BTRFS_ATTR_PTR(static_feature, rmdir_subvol), >> BTRFS_ATTR_PTR(static_feature, supported_checksums), >> BTRFS_ATTR_PTR(static_feature, send_stream_version), >> BTRFS_ATTR_PTR(static_feature, supported_rescue_options), >> + BTRFS_ATTR_PTR(static_feature, supported_ro_sectorsize), >> + BTRFS_ATTR_PTR(static_feature, supported_rw_sectorsize), >> NULL >> }; >> >
On Mon, Mar 15, 2021 at 08:39:31PM +0800, Qu Wenruo wrote: > > > On 2021/3/15 下午7:59, Anand Jain wrote: > > On 10/03/2021 17:08, Qu Wenruo wrote: > >> Add extra sysfs interface features/supported_ro_sectorsize and > >> features/supported_rw_sectorsize to indicate subpage support. > >> > >> Currently for supported_rw_sectorsize all architectures only have their > >> PAGE_SIZE listed. > >> > >> While for supported_ro_sectorsize, for systems with 64K page size, 4K > >> sectorsize is also supported. > >> > >> This new sysfs interface would help mkfs.btrfs to do more accurate > >> warning. > >> > >> Signed-off-by: Qu Wenruo <wqu@suse.com> > >> --- > > > > Changes looks good. Nit below... > > And maybe it is a good idea to wait for other comments before reroll. > > > >> fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ > >> 1 file changed, 34 insertions(+) > >> > >> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > >> index 6eb1c50fa98c..3ef419899472 100644 > >> --- a/fs/btrfs/sysfs.c > >> +++ b/fs/btrfs/sysfs.c > >> @@ -360,11 +360,45 @@ static ssize_t > >> supported_rescue_options_show(struct kobject *kobj, > >> BTRFS_ATTR(static_feature, supported_rescue_options, > >> supported_rescue_options_show); > >> +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, > >> + struct kobj_attribute *a, > >> + char *buf) > >> +{ > >> + ssize_t ret = 0; > >> + int i = 0; > > > > Drop variable i, as ret can be used instead of 'i'. > > > >> + > >> + /* For 64K page size, 4K sector size is supported */ > >> + if (PAGE_SIZE == SZ_64K) { > >> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); > >> + i++; > >> + } > >> + /* Other than above subpage, only support PAGE_SIZE as sectorsize > >> yet */ > >> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", > > > >> + (i ? " " : ""), PAGE_SIZE); > > ^ret > > > >> + return ret; > >> +} > >> +BTRFS_ATTR(static_feature, supported_ro_sectorsize, > >> + supported_ro_sectorsize_show); > >> + > >> +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, > >> + struct kobj_attribute *a, > >> + char *buf) > >> +{ > >> + ssize_t ret = 0; > >> + > >> + /* Only PAGE_SIZE as sectorsize is supported */ > >> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); > >> + return ret; > >> +} > >> +BTRFS_ATTR(static_feature, supported_rw_sectorsize, > >> + supported_rw_sectorsize_show); > > > > Why not merge supported_ro_sectorsize and supported_rw_sectorsize > > and show both in two lines... > > For example: > > cat supported_sectorsizes > > ro: 4096 65536 > > rw: 65536 > > If merged, btrfs-progs needs to do line number check before doing string > matching. The sysfs files should do one value per file. > Although I doubt the usefulness for supported_ro_sectorsize, as the > window for RO support without RW support should not be that large. > (Current RW passes most generic test cases, and the remaining failures > are very limited) > > Thus I can merged them into supported_sectorsize, and only report > sectorsize we can do RW as supported. In that case one file with the list of supported values is a better option. The main point is to have full RW support, until then it's interesting only for developers and they know what to expect.
On 2021/3/16 上午2:44, David Sterba wrote: > On Mon, Mar 15, 2021 at 08:39:31PM +0800, Qu Wenruo wrote: >> >> >> On 2021/3/15 下午7:59, Anand Jain wrote: >>> On 10/03/2021 17:08, Qu Wenruo wrote: >>>> Add extra sysfs interface features/supported_ro_sectorsize and >>>> features/supported_rw_sectorsize to indicate subpage support. >>>> >>>> Currently for supported_rw_sectorsize all architectures only have their >>>> PAGE_SIZE listed. >>>> >>>> While for supported_ro_sectorsize, for systems with 64K page size, 4K >>>> sectorsize is also supported. >>>> >>>> This new sysfs interface would help mkfs.btrfs to do more accurate >>>> warning. >>>> >>>> Signed-off-by: Qu Wenruo <wqu@suse.com> >>>> --- >>> >>> Changes looks good. Nit below... >>> And maybe it is a good idea to wait for other comments before reroll. >>> >>>> fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ >>>> 1 file changed, 34 insertions(+) >>>> >>>> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c >>>> index 6eb1c50fa98c..3ef419899472 100644 >>>> --- a/fs/btrfs/sysfs.c >>>> +++ b/fs/btrfs/sysfs.c >>>> @@ -360,11 +360,45 @@ static ssize_t >>>> supported_rescue_options_show(struct kobject *kobj, >>>> BTRFS_ATTR(static_feature, supported_rescue_options, >>>> supported_rescue_options_show); >>>> +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, >>>> + struct kobj_attribute *a, >>>> + char *buf) >>>> +{ >>>> + ssize_t ret = 0; >>>> + int i = 0; >>> >>> Drop variable i, as ret can be used instead of 'i'. >>> >>>> + >>>> + /* For 64K page size, 4K sector size is supported */ >>>> + if (PAGE_SIZE == SZ_64K) { >>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); >>>> + i++; >>>> + } >>>> + /* Other than above subpage, only support PAGE_SIZE as sectorsize >>>> yet */ >>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", >>> >>>> + (i ? " " : ""), PAGE_SIZE); >>> ^ret >>> >>>> + return ret; >>>> +} >>>> +BTRFS_ATTR(static_feature, supported_ro_sectorsize, >>>> + supported_ro_sectorsize_show); >>>> + >>>> +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, >>>> + struct kobj_attribute *a, >>>> + char *buf) >>>> +{ >>>> + ssize_t ret = 0; >>>> + >>>> + /* Only PAGE_SIZE as sectorsize is supported */ >>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); >>>> + return ret; >>>> +} >>>> +BTRFS_ATTR(static_feature, supported_rw_sectorsize, >>>> + supported_rw_sectorsize_show); >>> >>> Why not merge supported_ro_sectorsize and supported_rw_sectorsize >>> and show both in two lines... >>> For example: >>> cat supported_sectorsizes >>> ro: 4096 65536 >>> rw: 65536 >> >> If merged, btrfs-progs needs to do line number check before doing string >> matching. > > The sysfs files should do one value per file. > >> Although I doubt the usefulness for supported_ro_sectorsize, as the >> window for RO support without RW support should not be that large. >> (Current RW passes most generic test cases, and the remaining failures >> are very limited) >> >> Thus I can merged them into supported_sectorsize, and only report >> sectorsize we can do RW as supported. > > In that case one file with the list of supported values is a better > option. The main point is to have full RW support, until then it's > interesting only for developers and they know what to expect. > Indeed only full RW support makes sense. BTW, any comment on the file name? If no problem I would just use "supported_sectorsize" in next update. Although I hope the sysfs interface can be merged separately early, so that I can add the proper support in btrfs-progs. Thanks, Qu
On 16/03/2021 08:05, Qu Wenruo wrote: > > > On 2021/3/16 上午2:44, David Sterba wrote: >> On Mon, Mar 15, 2021 at 08:39:31PM +0800, Qu Wenruo wrote: >>> >>> >>> On 2021/3/15 下午7:59, Anand Jain wrote: >>>> On 10/03/2021 17:08, Qu Wenruo wrote: >>>>> Add extra sysfs interface features/supported_ro_sectorsize and >>>>> features/supported_rw_sectorsize to indicate subpage support. >>>>> >>>>> Currently for supported_rw_sectorsize all architectures only have >>>>> their >>>>> PAGE_SIZE listed. >>>>> >>>>> While for supported_ro_sectorsize, for systems with 64K page size, 4K >>>>> sectorsize is also supported. >>>>> >>>>> This new sysfs interface would help mkfs.btrfs to do more accurate >>>>> warning. >>>>> >>>>> Signed-off-by: Qu Wenruo <wqu@suse.com> >>>>> --- >>>> >>>> Changes looks good. Nit below... >>>> And maybe it is a good idea to wait for other comments before reroll. >>>> >>>>> fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ >>>>> 1 file changed, 34 insertions(+) >>>>> >>>>> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c >>>>> index 6eb1c50fa98c..3ef419899472 100644 >>>>> --- a/fs/btrfs/sysfs.c >>>>> +++ b/fs/btrfs/sysfs.c >>>>> @@ -360,11 +360,45 @@ static ssize_t >>>>> supported_rescue_options_show(struct kobject *kobj, >>>>> BTRFS_ATTR(static_feature, supported_rescue_options, >>>>> supported_rescue_options_show); >>>>> +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, >>>>> + struct kobj_attribute *a, >>>>> + char *buf) >>>>> +{ >>>>> + ssize_t ret = 0; >>>>> + int i = 0; >>>> >>>> Drop variable i, as ret can be used instead of 'i'. >>>> >>>>> + >>>>> + /* For 64K page size, 4K sector size is supported */ >>>>> + if (PAGE_SIZE == SZ_64K) { >>>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); >>>>> + i++; >>>>> + } >>>>> + /* Other than above subpage, only support PAGE_SIZE as sectorsize >>>>> yet */ >>>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", >>>> >>>>> + (i ? " " : ""), PAGE_SIZE); >>>> ^ret >>>> >>>>> + return ret; >>>>> +} >>>>> +BTRFS_ATTR(static_feature, supported_ro_sectorsize, >>>>> + supported_ro_sectorsize_show); >>>>> + >>>>> +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, >>>>> + struct kobj_attribute *a, >>>>> + char *buf) >>>>> +{ >>>>> + ssize_t ret = 0; >>>>> + >>>>> + /* Only PAGE_SIZE as sectorsize is supported */ >>>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); >>>>> + return ret; >>>>> +} >>>>> +BTRFS_ATTR(static_feature, supported_rw_sectorsize, >>>>> + supported_rw_sectorsize_show); >>>> >>>> Why not merge supported_ro_sectorsize and supported_rw_sectorsize >>>> and show both in two lines... >>>> For example: >>>> cat supported_sectorsizes >>>> ro: 4096 65536 >>>> rw: 65536 >>> >>> If merged, btrfs-progs needs to do line number check before doing string >>> matching. >> >> The sysfs files should do one value per file. >> >>> Although I doubt the usefulness for supported_ro_sectorsize, as the >>> window for RO support without RW support should not be that large. >>> (Current RW passes most generic test cases, and the remaining failures >>> are very limited) >>> >>> Thus I can merged them into supported_sectorsize, and only report >>> sectorsize we can do RW as supported. >> >> In that case one file with the list of supported values is a better >> option. The main point is to have full RW support, until then it's >> interesting only for developers and they know what to expect. >> > > Indeed only full RW support makes sense. > Makes sense to me. > BTW, any comment on the file name? If no problem I would just use > "supported_sectorsize" in next update. supported_sectorsizes (plural) is better IMO. Thanks, Anand > Although I hope the sysfs interface can be merged separately early, so > that I can add the proper support in btrfs-progs. > > Thanks, > Qu
On Tue, Mar 16, 2021 at 08:10:13AM +0800, Anand Jain wrote: > > > On 16/03/2021 08:05, Qu Wenruo wrote: > > > > > > On 2021/3/16 上午2:44, David Sterba wrote: > >> On Mon, Mar 15, 2021 at 08:39:31PM +0800, Qu Wenruo wrote: > >>> > >>> > >>> On 2021/3/15 下午7:59, Anand Jain wrote: > >>>> On 10/03/2021 17:08, Qu Wenruo wrote: > >>>>> Add extra sysfs interface features/supported_ro_sectorsize and > >>>>> features/supported_rw_sectorsize to indicate subpage support. > >>>>> > >>>>> Currently for supported_rw_sectorsize all architectures only have > >>>>> their > >>>>> PAGE_SIZE listed. > >>>>> > >>>>> While for supported_ro_sectorsize, for systems with 64K page size, 4K > >>>>> sectorsize is also supported. > >>>>> > >>>>> This new sysfs interface would help mkfs.btrfs to do more accurate > >>>>> warning. > >>>>> > >>>>> Signed-off-by: Qu Wenruo <wqu@suse.com> > >>>>> --- > >>>> > >>>> Changes looks good. Nit below... > >>>> And maybe it is a good idea to wait for other comments before reroll. > >>>> > >>>>> fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ > >>>>> 1 file changed, 34 insertions(+) > >>>>> > >>>>> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > >>>>> index 6eb1c50fa98c..3ef419899472 100644 > >>>>> --- a/fs/btrfs/sysfs.c > >>>>> +++ b/fs/btrfs/sysfs.c > >>>>> @@ -360,11 +360,45 @@ static ssize_t > >>>>> supported_rescue_options_show(struct kobject *kobj, > >>>>> BTRFS_ATTR(static_feature, supported_rescue_options, > >>>>> supported_rescue_options_show); > >>>>> +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, > >>>>> + struct kobj_attribute *a, > >>>>> + char *buf) > >>>>> +{ > >>>>> + ssize_t ret = 0; > >>>>> + int i = 0; > >>>> > >>>> Drop variable i, as ret can be used instead of 'i'. > >>>> > >>>>> + > >>>>> + /* For 64K page size, 4K sector size is supported */ > >>>>> + if (PAGE_SIZE == SZ_64K) { > >>>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); > >>>>> + i++; > >>>>> + } > >>>>> + /* Other than above subpage, only support PAGE_SIZE as sectorsize > >>>>> yet */ > >>>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", > >>>> > >>>>> + (i ? " " : ""), PAGE_SIZE); > >>>> ^ret > >>>> > >>>>> + return ret; > >>>>> +} > >>>>> +BTRFS_ATTR(static_feature, supported_ro_sectorsize, > >>>>> + supported_ro_sectorsize_show); > >>>>> + > >>>>> +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, > >>>>> + struct kobj_attribute *a, > >>>>> + char *buf) > >>>>> +{ > >>>>> + ssize_t ret = 0; > >>>>> + > >>>>> + /* Only PAGE_SIZE as sectorsize is supported */ > >>>>> + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); > >>>>> + return ret; > >>>>> +} > >>>>> +BTRFS_ATTR(static_feature, supported_rw_sectorsize, > >>>>> + supported_rw_sectorsize_show); > >>>> > >>>> Why not merge supported_ro_sectorsize and supported_rw_sectorsize > >>>> and show both in two lines... > >>>> For example: > >>>> cat supported_sectorsizes > >>>> ro: 4096 65536 > >>>> rw: 65536 > >>> > >>> If merged, btrfs-progs needs to do line number check before doing string > >>> matching. > >> > >> The sysfs files should do one value per file. > >> > >>> Although I doubt the usefulness for supported_ro_sectorsize, as the > >>> window for RO support without RW support should not be that large. > >>> (Current RW passes most generic test cases, and the remaining failures > >>> are very limited) > >>> > >>> Thus I can merged them into supported_sectorsize, and only report > >>> sectorsize we can do RW as supported. > >> > >> In that case one file with the list of supported values is a better > >> option. The main point is to have full RW support, until then it's > >> interesting only for developers and they know what to expect. > >> > > > > Indeed only full RW support makes sense. > > > Makes sense to me. > > > BTW, any comment on the file name? If no problem I would just use > > "supported_sectorsize" in next update. > > supported_sectorsizes (plural) is better IMO. Yeah pluar is consistent with what we have now, eg. supported_checksums
On Tue, Mar 16, 2021 at 08:05:31AM +0800, Qu Wenruo wrote: > > In that case one file with the list of supported values is a better > > option. The main point is to have full RW support, until then it's > > interesting only for developers and they know what to expect. > > > > Indeed only full RW support makes sense. > > BTW, any comment on the file name? If no problem I would just use > "supported_sectorsize" in next update. > > Although I hope the sysfs interface can be merged separately early, so > that I can add the proper support in btrfs-progs. Yeah, exporting the information via sysfs is the easy stuff so you can postpone it as you need.
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 6eb1c50fa98c..3ef419899472 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -360,11 +360,45 @@ static ssize_t supported_rescue_options_show(struct kobject *kobj, BTRFS_ATTR(static_feature, supported_rescue_options, supported_rescue_options_show); +static ssize_t supported_ro_sectorsize_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + ssize_t ret = 0; + int i = 0; + + /* For 64K page size, 4K sector size is supported */ + if (PAGE_SIZE == SZ_64K) { + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u", SZ_4K); + i++; + } + /* Other than above subpage, only support PAGE_SIZE as sectorsize yet */ + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%lu\n", + (i ? " " : ""), PAGE_SIZE); + return ret; +} +BTRFS_ATTR(static_feature, supported_ro_sectorsize, + supported_ro_sectorsize_show); + +static ssize_t supported_rw_sectorsize_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + ssize_t ret = 0; + + /* Only PAGE_SIZE as sectorsize is supported */ + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); + return ret; +} +BTRFS_ATTR(static_feature, supported_rw_sectorsize, + supported_rw_sectorsize_show); static struct attribute *btrfs_supported_static_feature_attrs[] = { BTRFS_ATTR_PTR(static_feature, rmdir_subvol), BTRFS_ATTR_PTR(static_feature, supported_checksums), BTRFS_ATTR_PTR(static_feature, send_stream_version), BTRFS_ATTR_PTR(static_feature, supported_rescue_options), + BTRFS_ATTR_PTR(static_feature, supported_ro_sectorsize), + BTRFS_ATTR_PTR(static_feature, supported_rw_sectorsize), NULL };
Add extra sysfs interface features/supported_ro_sectorsize and features/supported_rw_sectorsize to indicate subpage support. Currently for supported_rw_sectorsize all architectures only have their PAGE_SIZE listed. While for supported_ro_sectorsize, for systems with 64K page size, 4K sectorsize is also supported. This new sysfs interface would help mkfs.btrfs to do more accurate warning. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/sysfs.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)