[PATCH v2 01/15] btrfs: add sysfs interface for supported sectorsize
From: Qu Wenruo <hidden>
Date: 2021-03-10 09:09:17
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
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 <redacted> --- 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; + + /* 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 };
--
2.30.1