From fc57ad8d338cbe78c3f7565f3c0812938835fad8 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Thu, 25 Mar 2021 15:14:33 +0800 Subject: btrfs: add sysfs interface for supported sectorsize Export supported sector sizes in /sys/fs/btrfs/features/supported_sectorsizes. Currently all architectures have PAGE_SIZE, There's some disparity between read-only and read-write support but that will be unified in the future so there's only one file exporting the size. The read-only support for systems with 64K pages also works for 4K sector size. This new sysfs interface would help eg. mkfs.btrfs to print more accurate warnings about potentially incompatible option combinations. Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/sysfs.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs') diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 6eb1c50fa98c..a99d1f415a7f 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -360,11 +360,26 @@ 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_sectorsizes_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + ssize_t ret = 0; + + /* Only sectorsize == PAGE_SIZE is now supported */ + ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE); + + return ret; +} +BTRFS_ATTR(static_feature, supported_sectorsizes, + supported_sectorsizes_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_sectorsizes), NULL }; -- cgit