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 <w...@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
};
