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-rw-r--r--fs/btrfs/sysfs.c2397
1 files changed, 2397 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
new file mode 100644
index 0000000000..c9198723e4
--- /dev/null
+++ b/fs/btrfs/sysfs.c
@@ -0,0 +1,2397 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/bug.h>
+#include <linux/list.h>
+#include <crypto/hash.h>
+#include "messages.h"
+#include "ctree.h"
+#include "discard.h"
+#include "disk-io.h"
+#include "send.h"
+#include "transaction.h"
+#include "sysfs.h"
+#include "volumes.h"
+#include "space-info.h"
+#include "block-group.h"
+#include "qgroup.h"
+#include "misc.h"
+#include "fs.h"
+#include "accessors.h"
+
+/*
+ * Structure name Path
+ * --------------------------------------------------------------------------
+ * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
+ * btrfs_supported_feature_attrs /sys/fs/btrfs/features and
+ * /sys/fs/btrfs/<uuid>/features
+ * btrfs_attrs /sys/fs/btrfs/<uuid>
+ * devid_attrs /sys/fs/btrfs/<uuid>/devinfo/<devid>
+ * allocation_attrs /sys/fs/btrfs/<uuid>/allocation
+ * qgroup_attrs /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
+ * space_info_attrs /sys/fs/btrfs/<uuid>/allocation/<bg-type>
+ * raid_attrs /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
+ * discard_attrs /sys/fs/btrfs/<uuid>/discard
+ *
+ * When built with BTRFS_CONFIG_DEBUG:
+ *
+ * btrfs_debug_feature_attrs /sys/fs/btrfs/debug
+ * btrfs_debug_mount_attrs /sys/fs/btrfs/<uuid>/debug
+ */
+
+struct btrfs_feature_attr {
+ struct kobj_attribute kobj_attr;
+ enum btrfs_feature_set feature_set;
+ u64 feature_bit;
+};
+
+/* For raid type sysfs entries */
+struct raid_kobject {
+ u64 flags;
+ struct kobject kobj;
+};
+
+#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \
+{ \
+ .attr = { .name = __stringify(_name), .mode = _mode }, \
+ .show = _show, \
+ .store = _store, \
+}
+
+#define BTRFS_ATTR_W(_prefix, _name, _store) \
+ static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
+ __INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
+
+#define BTRFS_ATTR_RW(_prefix, _name, _show, _store) \
+ static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
+ __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
+
+#define BTRFS_ATTR(_prefix, _name, _show) \
+ static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
+ __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
+
+#define BTRFS_ATTR_PTR(_prefix, _name) \
+ (&btrfs_attr_##_prefix##_##_name.attr)
+
+#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit) \
+static struct btrfs_feature_attr btrfs_attr_features_##_name = { \
+ .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO, \
+ btrfs_feature_attr_show, \
+ btrfs_feature_attr_store), \
+ .feature_set = _feature_set, \
+ .feature_bit = _feature_prefix ##_## _feature_bit, \
+}
+#define BTRFS_FEAT_ATTR_PTR(_name) \
+ (&btrfs_attr_features_##_name.kobj_attr.attr)
+
+#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
+ BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
+#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
+ BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
+#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
+ BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
+
+static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
+static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
+static struct kobject *get_btrfs_kobj(struct kobject *kobj);
+
+static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
+{
+ return container_of(a, struct btrfs_feature_attr, kobj_attr);
+}
+
+static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
+{
+ return container_of(attr, struct kobj_attribute, attr);
+}
+
+static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
+ struct attribute *attr)
+{
+ return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
+}
+
+static u64 get_features(struct btrfs_fs_info *fs_info,
+ enum btrfs_feature_set set)
+{
+ struct btrfs_super_block *disk_super = fs_info->super_copy;
+ if (set == FEAT_COMPAT)
+ return btrfs_super_compat_flags(disk_super);
+ else if (set == FEAT_COMPAT_RO)
+ return btrfs_super_compat_ro_flags(disk_super);
+ else
+ return btrfs_super_incompat_flags(disk_super);
+}
+
+static void set_features(struct btrfs_fs_info *fs_info,
+ enum btrfs_feature_set set, u64 features)
+{
+ struct btrfs_super_block *disk_super = fs_info->super_copy;
+ if (set == FEAT_COMPAT)
+ btrfs_set_super_compat_flags(disk_super, features);
+ else if (set == FEAT_COMPAT_RO)
+ btrfs_set_super_compat_ro_flags(disk_super, features);
+ else
+ btrfs_set_super_incompat_flags(disk_super, features);
+}
+
+static int can_modify_feature(struct btrfs_feature_attr *fa)
+{
+ int val = 0;
+ u64 set, clear;
+ switch (fa->feature_set) {
+ case FEAT_COMPAT:
+ set = BTRFS_FEATURE_COMPAT_SAFE_SET;
+ clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
+ break;
+ case FEAT_COMPAT_RO:
+ set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
+ clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
+ break;
+ case FEAT_INCOMPAT:
+ set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
+ clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
+ break;
+ default:
+ pr_warn("btrfs: sysfs: unknown feature set %d\n",
+ fa->feature_set);
+ return 0;
+ }
+
+ if (set & fa->feature_bit)
+ val |= 1;
+ if (clear & fa->feature_bit)
+ val |= 2;
+
+ return val;
+}
+
+static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ int val = 0;
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
+ if (fs_info) {
+ u64 features = get_features(fs_info, fa->feature_set);
+ if (features & fa->feature_bit)
+ val = 1;
+ } else
+ val = can_modify_feature(fa);
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t count)
+{
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
+ u64 features, set, clear;
+ unsigned long val;
+ int ret;
+
+ fs_info = to_fs_info(kobj);
+ if (!fs_info)
+ return -EPERM;
+
+ if (sb_rdonly(fs_info->sb))
+ return -EROFS;
+
+ ret = kstrtoul(skip_spaces(buf), 0, &val);
+ if (ret)
+ return ret;
+
+ if (fa->feature_set == FEAT_COMPAT) {
+ set = BTRFS_FEATURE_COMPAT_SAFE_SET;
+ clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
+ } else if (fa->feature_set == FEAT_COMPAT_RO) {
+ set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
+ clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
+ } else {
+ set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
+ clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
+ }
+
+ features = get_features(fs_info, fa->feature_set);
+
+ /* Nothing to do */
+ if ((val && (features & fa->feature_bit)) ||
+ (!val && !(features & fa->feature_bit)))
+ return count;
+
+ if ((val && !(set & fa->feature_bit)) ||
+ (!val && !(clear & fa->feature_bit))) {
+ btrfs_info(fs_info,
+ "%sabling feature %s on mounted fs is not supported.",
+ val ? "En" : "Dis", fa->kobj_attr.attr.name);
+ return -EPERM;
+ }
+
+ btrfs_info(fs_info, "%s %s feature flag",
+ val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
+
+ spin_lock(&fs_info->super_lock);
+ features = get_features(fs_info, fa->feature_set);
+ if (val)
+ features |= fa->feature_bit;
+ else
+ features &= ~fa->feature_bit;
+ set_features(fs_info, fa->feature_set, features);
+ spin_unlock(&fs_info->super_lock);
+
+ /*
+ * We don't want to do full transaction commit from inside sysfs
+ */
+ set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
+ wake_up_process(fs_info->transaction_kthread);
+
+ return count;
+}
+
+static umode_t btrfs_feature_visible(struct kobject *kobj,
+ struct attribute *attr, int unused)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ umode_t mode = attr->mode;
+
+ if (fs_info) {
+ struct btrfs_feature_attr *fa;
+ u64 features;
+
+ fa = attr_to_btrfs_feature_attr(attr);
+ features = get_features(fs_info, fa->feature_set);
+
+ if (can_modify_feature(fa))
+ mode |= S_IWUSR;
+ else if (!(features & fa->feature_bit))
+ mode = 0;
+ }
+
+ return mode;
+}
+
+BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
+BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
+BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
+BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
+BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
+BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
+BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
+BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
+BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
+BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
+BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
+BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
+#ifdef CONFIG_BLK_DEV_ZONED
+BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
+#endif
+#ifdef CONFIG_BTRFS_DEBUG
+/* Remove once support for extent tree v2 is feature complete */
+BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
+#endif
+#ifdef CONFIG_FS_VERITY
+BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
+#endif
+
+/*
+ * Features which depend on feature bits and may differ between each fs.
+ *
+ * /sys/fs/btrfs/features - all available features implemented by this version
+ * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
+ * can be changed on a mounted filesystem.
+ */
+static struct attribute *btrfs_supported_feature_attrs[] = {
+ BTRFS_FEAT_ATTR_PTR(default_subvol),
+ BTRFS_FEAT_ATTR_PTR(mixed_groups),
+ BTRFS_FEAT_ATTR_PTR(compress_lzo),
+ BTRFS_FEAT_ATTR_PTR(compress_zstd),
+ BTRFS_FEAT_ATTR_PTR(extended_iref),
+ BTRFS_FEAT_ATTR_PTR(raid56),
+ BTRFS_FEAT_ATTR_PTR(skinny_metadata),
+ BTRFS_FEAT_ATTR_PTR(no_holes),
+ BTRFS_FEAT_ATTR_PTR(metadata_uuid),
+ BTRFS_FEAT_ATTR_PTR(free_space_tree),
+ BTRFS_FEAT_ATTR_PTR(raid1c34),
+ BTRFS_FEAT_ATTR_PTR(block_group_tree),
+#ifdef CONFIG_BLK_DEV_ZONED
+ BTRFS_FEAT_ATTR_PTR(zoned),
+#endif
+#ifdef CONFIG_BTRFS_DEBUG
+ BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
+#endif
+#ifdef CONFIG_FS_VERITY
+ BTRFS_FEAT_ATTR_PTR(verity),
+#endif
+ NULL
+};
+
+static const struct attribute_group btrfs_feature_attr_group = {
+ .name = "features",
+ .is_visible = btrfs_feature_visible,
+ .attrs = btrfs_supported_feature_attrs,
+};
+
+static ssize_t rmdir_subvol_show(struct kobject *kobj,
+ struct kobj_attribute *ka, char *buf)
+{
+ return sysfs_emit(buf, "0\n");
+}
+BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
+
+static ssize_t supported_checksums_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ ssize_t ret = 0;
+ int i;
+
+ for (i = 0; i < btrfs_get_num_csums(); i++) {
+ /*
+ * This "trick" only works as long as 'enum btrfs_csum_type' has
+ * no holes in it
+ */
+ ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
+ btrfs_super_csum_name(i));
+
+ }
+
+ ret += sysfs_emit_at(buf, ret, "\n");
+ return ret;
+}
+BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
+
+static ssize_t send_stream_version_show(struct kobject *kobj,
+ struct kobj_attribute *ka, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
+}
+BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
+
+static const char *rescue_opts[] = {
+ "usebackuproot",
+ "nologreplay",
+ "ignorebadroots",
+ "ignoredatacsums",
+ "all",
+};
+
+static ssize_t supported_rescue_options_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ ssize_t ret = 0;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
+ ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
+ ret += sysfs_emit_at(buf, ret, "\n");
+ return ret;
+}
+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;
+
+ /* An artificial limit to only support 4K and PAGE_SIZE */
+ if (PAGE_SIZE > SZ_4K)
+ ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
+ ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
+
+ return ret;
+}
+BTRFS_ATTR(static_feature, supported_sectorsizes,
+ supported_sectorsizes_show);
+
+static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
+}
+BTRFS_ATTR(static_feature, acl, acl_show);
+
+/*
+ * Features which only depend on kernel version.
+ *
+ * These are listed in /sys/fs/btrfs/features along with
+ * btrfs_supported_feature_attrs.
+ */
+static struct attribute *btrfs_supported_static_feature_attrs[] = {
+ BTRFS_ATTR_PTR(static_feature, acl),
+ 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
+};
+
+static const struct attribute_group btrfs_static_feature_attr_group = {
+ .name = "features",
+ .attrs = btrfs_supported_static_feature_attrs,
+};
+
+/*
+ * Discard statistics and tunables
+ */
+#define discard_to_fs_info(_kobj) to_fs_info(get_btrfs_kobj(_kobj))
+
+static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%lld\n",
+ atomic64_read(&fs_info->discard_ctl.discardable_bytes));
+}
+BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
+
+static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%d\n",
+ atomic_read(&fs_info->discard_ctl.discardable_extents));
+}
+BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
+
+static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%llu\n",
+ fs_info->discard_ctl.discard_bitmap_bytes);
+}
+BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
+
+static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%lld\n",
+ atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
+}
+BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
+
+static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%llu\n",
+ fs_info->discard_ctl.discard_extent_bytes);
+}
+BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
+
+static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%u\n",
+ READ_ONCE(fs_info->discard_ctl.iops_limit));
+}
+
+static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+ struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
+ u32 iops_limit;
+ int ret;
+
+ ret = kstrtou32(buf, 10, &iops_limit);
+ if (ret)
+ return -EINVAL;
+
+ WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
+ btrfs_discard_calc_delay(discard_ctl);
+ btrfs_discard_schedule_work(discard_ctl, true);
+ return len;
+}
+BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
+ btrfs_discard_iops_limit_store);
+
+static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%u\n",
+ READ_ONCE(fs_info->discard_ctl.kbps_limit));
+}
+
+static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+ struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
+ u32 kbps_limit;
+ int ret;
+
+ ret = kstrtou32(buf, 10, &kbps_limit);
+ if (ret)
+ return -EINVAL;
+
+ WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
+ btrfs_discard_schedule_work(discard_ctl, true);
+ return len;
+}
+BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
+ btrfs_discard_kbps_limit_store);
+
+static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%llu\n",
+ READ_ONCE(fs_info->discard_ctl.max_discard_size));
+}
+
+static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+ struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
+ u64 max_discard_size;
+ int ret;
+
+ ret = kstrtou64(buf, 10, &max_discard_size);
+ if (ret)
+ return -EINVAL;
+
+ WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
+
+ return len;
+}
+BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
+ btrfs_discard_max_discard_size_store);
+
+/*
+ * Per-filesystem stats for discard (when mounted with discard=async).
+ *
+ * Path: /sys/fs/btrfs/<uuid>/discard/
+ */
+static const struct attribute *discard_attrs[] = {
+ BTRFS_ATTR_PTR(discard, discardable_bytes),
+ BTRFS_ATTR_PTR(discard, discardable_extents),
+ BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
+ BTRFS_ATTR_PTR(discard, discard_bytes_saved),
+ BTRFS_ATTR_PTR(discard, discard_extent_bytes),
+ BTRFS_ATTR_PTR(discard, iops_limit),
+ BTRFS_ATTR_PTR(discard, kbps_limit),
+ BTRFS_ATTR_PTR(discard, max_discard_size),
+ NULL,
+};
+
+#ifdef CONFIG_BTRFS_DEBUG
+
+/*
+ * Per-filesystem runtime debugging exported via sysfs.
+ *
+ * Path: /sys/fs/btrfs/UUID/debug/
+ */
+static const struct attribute *btrfs_debug_mount_attrs[] = {
+ NULL,
+};
+
+/*
+ * Runtime debugging exported via sysfs, applies to all mounted filesystems.
+ *
+ * Path: /sys/fs/btrfs/debug
+ */
+static struct attribute *btrfs_debug_feature_attrs[] = {
+ NULL
+};
+
+static const struct attribute_group btrfs_debug_feature_attr_group = {
+ .name = "debug",
+ .attrs = btrfs_debug_feature_attrs,
+};
+
+#endif
+
+static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
+{
+ u64 val;
+ if (lock)
+ spin_lock(lock);
+ val = *value_ptr;
+ if (lock)
+ spin_unlock(lock);
+ return sysfs_emit(buf, "%llu\n", val);
+}
+
+static ssize_t global_rsv_size_show(struct kobject *kobj,
+ struct kobj_attribute *ka, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
+ struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
+ return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
+}
+BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
+
+static ssize_t global_rsv_reserved_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
+ struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
+ return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
+}
+BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
+
+#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
+#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
+
+static ssize_t raid_bytes_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf);
+BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
+BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
+
+static ssize_t raid_bytes_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+
+{
+ struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
+ struct btrfs_block_group *block_group;
+ int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
+ u64 val = 0;
+
+ down_read(&sinfo->groups_sem);
+ list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
+ if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
+ val += block_group->length;
+ else
+ val += block_group->used;
+ }
+ up_read(&sinfo->groups_sem);
+ return sysfs_emit(buf, "%llu\n", val);
+}
+
+/*
+ * Allocation information about block group profiles.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
+ */
+static struct attribute *raid_attrs[] = {
+ BTRFS_ATTR_PTR(raid, total_bytes),
+ BTRFS_ATTR_PTR(raid, used_bytes),
+ NULL
+};
+ATTRIBUTE_GROUPS(raid);
+
+static void release_raid_kobj(struct kobject *kobj)
+{
+ kfree(to_raid_kobj(kobj));
+}
+
+static const struct kobj_type btrfs_raid_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = release_raid_kobj,
+ .default_groups = raid_groups,
+};
+
+#define SPACE_INFO_ATTR(field) \
+static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
+ struct kobj_attribute *a, \
+ char *buf) \
+{ \
+ struct btrfs_space_info *sinfo = to_space_info(kobj); \
+ return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
+} \
+BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
+
+static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_space_info *sinfo = to_space_info(kobj);
+
+ return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
+}
+
+/*
+ * Store new chunk size in space info. Can be called on a read-only filesystem.
+ *
+ * If the new chunk size value is larger than 10% of free space it is reduced
+ * to match that limit. Alignment must be to 256M and the system chunk size
+ * cannot be set.
+ */
+static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_space_info *space_info = to_space_info(kobj);
+ struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
+ char *retptr;
+ u64 val;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!fs_info->fs_devices)
+ return -EINVAL;
+
+ if (btrfs_is_zoned(fs_info))
+ return -EINVAL;
+
+ /* System block type must not be changed. */
+ if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
+ return -EPERM;
+
+ val = memparse(buf, &retptr);
+ /* There could be trailing '\n', also catch any typos after the value */
+ retptr = skip_spaces(retptr);
+ if (*retptr != 0 || val == 0)
+ return -EINVAL;
+
+ val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
+
+ /* Limit stripe size to 10% of available space. */
+ val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
+
+ /* Must be multiple of 256M. */
+ val &= ~((u64)SZ_256M - 1);
+
+ /* Must be at least 256M. */
+ if (val < SZ_256M)
+ return -EINVAL;
+
+ btrfs_update_space_info_chunk_size(space_info, val);
+
+ return len;
+}
+
+static ssize_t btrfs_size_classes_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_space_info *sinfo = to_space_info(kobj);
+ struct btrfs_block_group *bg;
+ u32 none = 0;
+ u32 small = 0;
+ u32 medium = 0;
+ u32 large = 0;
+
+ for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
+ down_read(&sinfo->groups_sem);
+ list_for_each_entry(bg, &sinfo->block_groups[i], list) {
+ if (!btrfs_block_group_should_use_size_class(bg))
+ continue;
+ switch (bg->size_class) {
+ case BTRFS_BG_SZ_NONE:
+ none++;
+ break;
+ case BTRFS_BG_SZ_SMALL:
+ small++;
+ break;
+ case BTRFS_BG_SZ_MEDIUM:
+ medium++;
+ break;
+ case BTRFS_BG_SZ_LARGE:
+ large++;
+ break;
+ }
+ }
+ up_read(&sinfo->groups_sem);
+ }
+ return sysfs_emit(buf, "none %u\n"
+ "small %u\n"
+ "medium %u\n"
+ "large %u\n",
+ none, small, medium, large);
+}
+
+#ifdef CONFIG_BTRFS_DEBUG
+/*
+ * Request chunk allocation with current chunk size.
+ */
+static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_space_info *space_info = to_space_info(kobj);
+ struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
+ struct btrfs_trans_handle *trans;
+ bool val;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (sb_rdonly(fs_info->sb))
+ return -EROFS;
+
+ ret = kstrtobool(buf, &val);
+ if (ret)
+ return ret;
+
+ if (!val)
+ return -EINVAL;
+
+ /*
+ * This is unsafe to be called from sysfs context and may cause
+ * unexpected problems.
+ */
+ trans = btrfs_start_transaction(fs_info->tree_root, 0);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+ ret = btrfs_force_chunk_alloc(trans, space_info->flags);
+ btrfs_end_transaction(trans);
+
+ if (ret == 1)
+ return len;
+
+ return -ENOSPC;
+}
+BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
+
+#endif
+
+SPACE_INFO_ATTR(flags);
+SPACE_INFO_ATTR(total_bytes);
+SPACE_INFO_ATTR(bytes_used);
+SPACE_INFO_ATTR(bytes_pinned);
+SPACE_INFO_ATTR(bytes_reserved);
+SPACE_INFO_ATTR(bytes_may_use);
+SPACE_INFO_ATTR(bytes_readonly);
+SPACE_INFO_ATTR(bytes_zone_unusable);
+SPACE_INFO_ATTR(disk_used);
+SPACE_INFO_ATTR(disk_total);
+BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
+BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
+
+static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_space_info *space_info = to_space_info(kobj);
+
+ return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
+}
+
+static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_space_info *space_info = to_space_info(kobj);
+ int thresh;
+ int ret;
+
+ ret = kstrtoint(buf, 10, &thresh);
+ if (ret)
+ return ret;
+
+ if (thresh < 0 || thresh > 100)
+ return -EINVAL;
+
+ WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
+
+ return len;
+}
+
+BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
+ btrfs_sinfo_bg_reclaim_threshold_show,
+ btrfs_sinfo_bg_reclaim_threshold_store);
+
+/*
+ * Allocation information about block group types.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
+ */
+static struct attribute *space_info_attrs[] = {
+ BTRFS_ATTR_PTR(space_info, flags),
+ BTRFS_ATTR_PTR(space_info, total_bytes),
+ BTRFS_ATTR_PTR(space_info, bytes_used),
+ BTRFS_ATTR_PTR(space_info, bytes_pinned),
+ BTRFS_ATTR_PTR(space_info, bytes_reserved),
+ BTRFS_ATTR_PTR(space_info, bytes_may_use),
+ BTRFS_ATTR_PTR(space_info, bytes_readonly),
+ BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
+ BTRFS_ATTR_PTR(space_info, disk_used),
+ BTRFS_ATTR_PTR(space_info, disk_total),
+ BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
+ BTRFS_ATTR_PTR(space_info, chunk_size),
+ BTRFS_ATTR_PTR(space_info, size_classes),
+#ifdef CONFIG_BTRFS_DEBUG
+ BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
+#endif
+ NULL,
+};
+ATTRIBUTE_GROUPS(space_info);
+
+static void space_info_release(struct kobject *kobj)
+{
+ struct btrfs_space_info *sinfo = to_space_info(kobj);
+ kfree(sinfo);
+}
+
+static const struct kobj_type space_info_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = space_info_release,
+ .default_groups = space_info_groups,
+};
+
+/*
+ * Allocation information about block groups.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/allocation/
+ */
+static const struct attribute *allocation_attrs[] = {
+ BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
+ BTRFS_ATTR_PTR(allocation, global_rsv_size),
+ NULL,
+};
+
+static ssize_t btrfs_label_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ char *label = fs_info->super_copy->label;
+ ssize_t ret;
+
+ spin_lock(&fs_info->super_lock);
+ ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
+ spin_unlock(&fs_info->super_lock);
+
+ return ret;
+}
+
+static ssize_t btrfs_label_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ size_t p_len;
+
+ if (!fs_info)
+ return -EPERM;
+
+ if (sb_rdonly(fs_info->sb))
+ return -EROFS;
+
+ /*
+ * p_len is the len until the first occurrence of either
+ * '\n' or '\0'
+ */
+ p_len = strcspn(buf, "\n");
+
+ if (p_len >= BTRFS_LABEL_SIZE)
+ return -EINVAL;
+
+ spin_lock(&fs_info->super_lock);
+ memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
+ memcpy(fs_info->super_copy->label, buf, p_len);
+ spin_unlock(&fs_info->super_lock);
+
+ /*
+ * We don't want to do full transaction commit from inside sysfs
+ */
+ set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
+ wake_up_process(fs_info->transaction_kthread);
+
+ return len;
+}
+BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
+
+static ssize_t btrfs_nodesize_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
+}
+
+BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
+
+static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
+}
+
+BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
+
+static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf,
+ "commits %llu\n"
+ "last_commit_ms %llu\n"
+ "max_commit_ms %llu\n"
+ "total_commit_ms %llu\n",
+ fs_info->commit_stats.commit_count,
+ div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
+ div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
+ div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
+}
+
+static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ unsigned long val;
+ int ret;
+
+ if (!fs_info)
+ return -EPERM;
+
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+ if (val)
+ return -EINVAL;
+
+ WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
+
+ return len;
+}
+BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
+
+static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
+}
+
+BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
+
+static ssize_t quota_override_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ int quota_override;
+
+ quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
+ return sysfs_emit(buf, "%d\n", quota_override);
+}
+
+static ssize_t quota_override_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ unsigned long knob;
+ int err;
+
+ if (!fs_info)
+ return -EPERM;
+
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+
+ err = kstrtoul(buf, 10, &knob);
+ if (err)
+ return err;
+ if (knob > 1)
+ return -EINVAL;
+
+ if (knob)
+ set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
+ else
+ clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
+
+ return len;
+}
+
+BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
+
+static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
+}
+
+BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
+
+static ssize_t btrfs_checksum_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
+
+ return sysfs_emit(buf, "%s (%s)\n",
+ btrfs_super_csum_name(csum_type),
+ crypto_shash_driver_name(fs_info->csum_shash));
+}
+
+BTRFS_ATTR(, checksum, btrfs_checksum_show);
+
+static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ const char *str;
+
+ switch (READ_ONCE(fs_info->exclusive_operation)) {
+ case BTRFS_EXCLOP_NONE:
+ str = "none\n";
+ break;
+ case BTRFS_EXCLOP_BALANCE:
+ str = "balance\n";
+ break;
+ case BTRFS_EXCLOP_BALANCE_PAUSED:
+ str = "balance paused\n";
+ break;
+ case BTRFS_EXCLOP_DEV_ADD:
+ str = "device add\n";
+ break;
+ case BTRFS_EXCLOP_DEV_REMOVE:
+ str = "device remove\n";
+ break;
+ case BTRFS_EXCLOP_DEV_REPLACE:
+ str = "device replace\n";
+ break;
+ case BTRFS_EXCLOP_RESIZE:
+ str = "resize\n";
+ break;
+ case BTRFS_EXCLOP_SWAP_ACTIVATE:
+ str = "swap activate\n";
+ break;
+ default:
+ str = "UNKNOWN\n";
+ break;
+ }
+ return sysfs_emit(buf, "%s", str);
+}
+BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
+
+static ssize_t btrfs_generation_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%llu\n", fs_info->generation);
+}
+BTRFS_ATTR(, generation, btrfs_generation_show);
+
+static const char * const btrfs_read_policy_name[] = { "pid" };
+
+static ssize_t btrfs_read_policy_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
+ ssize_t ret = 0;
+ int i;
+
+ for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
+ if (fs_devices->read_policy == i)
+ ret += sysfs_emit_at(buf, ret, "%s[%s]",
+ (ret == 0 ? "" : " "),
+ btrfs_read_policy_name[i]);
+ else
+ ret += sysfs_emit_at(buf, ret, "%s%s",
+ (ret == 0 ? "" : " "),
+ btrfs_read_policy_name[i]);
+ }
+
+ ret += sysfs_emit_at(buf, ret, "\n");
+
+ return ret;
+}
+
+static ssize_t btrfs_read_policy_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
+ int i;
+
+ for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
+ if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
+ if (i != fs_devices->read_policy) {
+ fs_devices->read_policy = i;
+ btrfs_info(fs_devices->fs_info,
+ "read policy set to '%s'",
+ btrfs_read_policy_name[i]);
+ }
+ return len;
+ }
+ }
+
+ return -EINVAL;
+}
+BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
+
+static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+ return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
+}
+
+static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ int thresh;
+ int ret;
+
+ ret = kstrtoint(buf, 10, &thresh);
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_BTRFS_DEBUG
+ if (thresh != 0 && (thresh > 100))
+ return -EINVAL;
+#else
+ if (thresh != 0 && (thresh <= 50 || thresh > 100))
+ return -EINVAL;
+#endif
+
+ WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
+
+ return len;
+}
+BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
+ btrfs_bg_reclaim_threshold_store);
+
+/*
+ * Per-filesystem information and stats.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/
+ */
+static const struct attribute *btrfs_attrs[] = {
+ BTRFS_ATTR_PTR(, label),
+ BTRFS_ATTR_PTR(, nodesize),
+ BTRFS_ATTR_PTR(, sectorsize),
+ BTRFS_ATTR_PTR(, clone_alignment),
+ BTRFS_ATTR_PTR(, quota_override),
+ BTRFS_ATTR_PTR(, metadata_uuid),
+ BTRFS_ATTR_PTR(, checksum),
+ BTRFS_ATTR_PTR(, exclusive_operation),
+ BTRFS_ATTR_PTR(, generation),
+ BTRFS_ATTR_PTR(, read_policy),
+ BTRFS_ATTR_PTR(, bg_reclaim_threshold),
+ BTRFS_ATTR_PTR(, commit_stats),
+ NULL,
+};
+
+static void btrfs_release_fsid_kobj(struct kobject *kobj)
+{
+ struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
+
+ memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
+ complete(&fs_devs->kobj_unregister);
+}
+
+static const struct kobj_type btrfs_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = btrfs_release_fsid_kobj,
+};
+
+static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
+{
+ if (kobj->ktype != &btrfs_ktype)
+ return NULL;
+ return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
+}
+
+static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
+{
+ if (kobj->ktype != &btrfs_ktype)
+ return NULL;
+ return to_fs_devs(kobj)->fs_info;
+}
+
+static struct kobject *get_btrfs_kobj(struct kobject *kobj)
+{
+ while (kobj) {
+ if (kobj->ktype == &btrfs_ktype)
+ return kobj;
+ kobj = kobj->parent;
+ }
+ return NULL;
+}
+
+#define NUM_FEATURE_BITS 64
+#define BTRFS_FEATURE_NAME_MAX 13
+static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
+static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
+
+static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
+ ARRAY_SIZE(btrfs_feature_attrs));
+static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
+ ARRAY_SIZE(btrfs_feature_attrs[0]));
+
+static const u64 supported_feature_masks[FEAT_MAX] = {
+ [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
+ [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
+ [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
+};
+
+static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
+{
+ int set;
+
+ for (set = 0; set < FEAT_MAX; set++) {
+ int i;
+ struct attribute *attrs[2];
+ struct attribute_group agroup = {
+ .name = "features",
+ .attrs = attrs,
+ };
+ u64 features = get_features(fs_info, set);
+ features &= ~supported_feature_masks[set];
+
+ if (!features)
+ continue;
+
+ attrs[1] = NULL;
+ for (i = 0; i < NUM_FEATURE_BITS; i++) {
+ struct btrfs_feature_attr *fa;
+
+ if (!(features & (1ULL << i)))
+ continue;
+
+ fa = &btrfs_feature_attrs[set][i];
+ attrs[0] = &fa->kobj_attr.attr;
+ if (add) {
+ int ret;
+ ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
+ &agroup);
+ if (ret)
+ return ret;
+ } else
+ sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
+ &agroup);
+ }
+
+ }
+ return 0;
+}
+
+static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
+{
+ if (fs_devs->devinfo_kobj) {
+ kobject_del(fs_devs->devinfo_kobj);
+ kobject_put(fs_devs->devinfo_kobj);
+ fs_devs->devinfo_kobj = NULL;
+ }
+
+ if (fs_devs->devices_kobj) {
+ kobject_del(fs_devs->devices_kobj);
+ kobject_put(fs_devs->devices_kobj);
+ fs_devs->devices_kobj = NULL;
+ }
+
+ if (fs_devs->fsid_kobj.state_initialized) {
+ kobject_del(&fs_devs->fsid_kobj);
+ kobject_put(&fs_devs->fsid_kobj);
+ wait_for_completion(&fs_devs->kobj_unregister);
+ }
+}
+
+/* when fs_devs is NULL it will remove all fsid kobject */
+void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
+{
+ struct list_head *fs_uuids = btrfs_get_fs_uuids();
+
+ if (fs_devs) {
+ __btrfs_sysfs_remove_fsid(fs_devs);
+ return;
+ }
+
+ list_for_each_entry(fs_devs, fs_uuids, fs_list) {
+ __btrfs_sysfs_remove_fsid(fs_devs);
+ }
+}
+
+static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *seed;
+
+ list_for_each_entry(device, &fs_devices->devices, dev_list)
+ btrfs_sysfs_remove_device(device);
+
+ list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
+ list_for_each_entry(device, &seed->devices, dev_list)
+ btrfs_sysfs_remove_device(device);
+ }
+}
+
+void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
+{
+ struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
+
+ sysfs_remove_link(fsid_kobj, "bdi");
+
+ if (fs_info->space_info_kobj) {
+ sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
+ kobject_del(fs_info->space_info_kobj);
+ kobject_put(fs_info->space_info_kobj);
+ }
+ if (fs_info->discard_kobj) {
+ sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
+ kobject_del(fs_info->discard_kobj);
+ kobject_put(fs_info->discard_kobj);
+ }
+#ifdef CONFIG_BTRFS_DEBUG
+ if (fs_info->debug_kobj) {
+ sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
+ kobject_del(fs_info->debug_kobj);
+ kobject_put(fs_info->debug_kobj);
+ }
+#endif
+ addrm_unknown_feature_attrs(fs_info, false);
+ sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
+ sysfs_remove_files(fsid_kobj, btrfs_attrs);
+ btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
+}
+
+static const char * const btrfs_feature_set_names[FEAT_MAX] = {
+ [FEAT_COMPAT] = "compat",
+ [FEAT_COMPAT_RO] = "compat_ro",
+ [FEAT_INCOMPAT] = "incompat",
+};
+
+const char *btrfs_feature_set_name(enum btrfs_feature_set set)
+{
+ return btrfs_feature_set_names[set];
+}
+
+char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
+{
+ size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
+ int len = 0;
+ int i;
+ char *str;
+
+ str = kmalloc(bufsize, GFP_KERNEL);
+ if (!str)
+ return str;
+
+ for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
+ const char *name;
+
+ if (!(flags & (1ULL << i)))
+ continue;
+
+ name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
+ len += scnprintf(str + len, bufsize - len, "%s%s",
+ len ? "," : "", name);
+ }
+
+ return str;
+}
+
+static void init_feature_attrs(void)
+{
+ struct btrfs_feature_attr *fa;
+ int set, i;
+
+ memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
+ memset(btrfs_unknown_feature_names, 0,
+ sizeof(btrfs_unknown_feature_names));
+
+ for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
+ struct btrfs_feature_attr *sfa;
+ struct attribute *a = btrfs_supported_feature_attrs[i];
+ int bit;
+ sfa = attr_to_btrfs_feature_attr(a);
+ bit = ilog2(sfa->feature_bit);
+ fa = &btrfs_feature_attrs[sfa->feature_set][bit];
+
+ fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
+ }
+
+ for (set = 0; set < FEAT_MAX; set++) {
+ for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
+ char *name = btrfs_unknown_feature_names[set][i];
+ fa = &btrfs_feature_attrs[set][i];
+
+ if (fa->kobj_attr.attr.name)
+ continue;
+
+ snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
+ btrfs_feature_set_names[set], i);
+
+ fa->kobj_attr.attr.name = name;
+ fa->kobj_attr.attr.mode = S_IRUGO;
+ fa->feature_set = set;
+ fa->feature_bit = 1ULL << i;
+ }
+ }
+}
+
+/*
+ * Create a sysfs entry for a given block group type at path
+ * /sys/fs/btrfs/UUID/allocation/data/TYPE
+ */
+void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
+{
+ struct btrfs_fs_info *fs_info = cache->fs_info;
+ struct btrfs_space_info *space_info = cache->space_info;
+ struct raid_kobject *rkobj;
+ const int index = btrfs_bg_flags_to_raid_index(cache->flags);
+ unsigned int nofs_flag;
+ int ret;
+
+ /*
+ * Setup a NOFS context because kobject_add(), deep in its call chain,
+ * does GFP_KERNEL allocations, and we are often called in a context
+ * where if reclaim is triggered we can deadlock (we are either holding
+ * a transaction handle or some lock required for a transaction
+ * commit).
+ */
+ nofs_flag = memalloc_nofs_save();
+
+ rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
+ if (!rkobj) {
+ memalloc_nofs_restore(nofs_flag);
+ btrfs_warn(cache->fs_info,
+ "couldn't alloc memory for raid level kobject");
+ return;
+ }
+
+ rkobj->flags = cache->flags;
+ kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
+
+ /*
+ * We call this either on mount, or if we've created a block group for a
+ * new index type while running (i.e. when restriping). The running
+ * case is tricky because we could race with other threads, so we need
+ * to have this check to make sure we didn't already init the kobject.
+ *
+ * We don't have to protect on the free side because it only happens on
+ * unmount.
+ */
+ spin_lock(&space_info->lock);
+ if (space_info->block_group_kobjs[index]) {
+ spin_unlock(&space_info->lock);
+ kobject_put(&rkobj->kobj);
+ return;
+ } else {
+ space_info->block_group_kobjs[index] = &rkobj->kobj;
+ }
+ spin_unlock(&space_info->lock);
+
+ ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
+ btrfs_bg_type_to_raid_name(rkobj->flags));
+ memalloc_nofs_restore(nofs_flag);
+ if (ret) {
+ spin_lock(&space_info->lock);
+ space_info->block_group_kobjs[index] = NULL;
+ spin_unlock(&space_info->lock);
+ kobject_put(&rkobj->kobj);
+ btrfs_warn(fs_info,
+ "failed to add kobject for block cache, ignoring");
+ return;
+ }
+}
+
+/*
+ * Remove sysfs directories for all block group types of a given space info and
+ * the space info as well
+ */
+void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
+{
+ int i;
+
+ for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
+ struct kobject *kobj;
+
+ kobj = space_info->block_group_kobjs[i];
+ space_info->block_group_kobjs[i] = NULL;
+ if (kobj) {
+ kobject_del(kobj);
+ kobject_put(kobj);
+ }
+ }
+ kobject_del(&space_info->kobj);
+ kobject_put(&space_info->kobj);
+}
+
+static const char *alloc_name(u64 flags)
+{
+ switch (flags) {
+ case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
+ return "mixed";
+ case BTRFS_BLOCK_GROUP_METADATA:
+ return "metadata";
+ case BTRFS_BLOCK_GROUP_DATA:
+ return "data";
+ case BTRFS_BLOCK_GROUP_SYSTEM:
+ return "system";
+ default:
+ WARN_ON(1);
+ return "invalid-combination";
+ }
+}
+
+/*
+ * Create a sysfs entry for a space info type at path
+ * /sys/fs/btrfs/UUID/allocation/TYPE
+ */
+int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *space_info)
+{
+ int ret;
+
+ ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
+ fs_info->space_info_kobj, "%s",
+ alloc_name(space_info->flags));
+ if (ret) {
+ kobject_put(&space_info->kobj);
+ return ret;
+ }
+
+ return 0;
+}
+
+void btrfs_sysfs_remove_device(struct btrfs_device *device)
+{
+ struct kobject *devices_kobj;
+
+ /*
+ * Seed fs_devices devices_kobj aren't used, fetch kobject from the
+ * fs_info::fs_devices.
+ */
+ devices_kobj = device->fs_info->fs_devices->devices_kobj;
+ ASSERT(devices_kobj);
+
+ if (device->bdev)
+ sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
+
+ if (device->devid_kobj.state_initialized) {
+ kobject_del(&device->devid_kobj);
+ kobject_put(&device->devid_kobj);
+ wait_for_completion(&device->kobj_unregister);
+ }
+}
+
+static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ int val;
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
+
+static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ int val;
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
+
+static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ int val;
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
+
+static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
+}
+
+static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+ char *endptr;
+ unsigned long long limit;
+
+ limit = memparse(buf, &endptr);
+ /* There could be trailing '\n', also catch any typos after the value. */
+ endptr = skip_spaces(endptr);
+ if (*endptr != 0)
+ return -EINVAL;
+ WRITE_ONCE(device->scrub_speed_max, limit);
+ return len;
+}
+BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
+ btrfs_devinfo_scrub_speed_max_store);
+
+static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ int val;
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
+
+static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
+}
+BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
+
+static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ if (!device->dev_stats_valid)
+ return sysfs_emit(buf, "invalid\n");
+
+ /*
+ * Print all at once so we get a snapshot of all values from the same
+ * time. Keep them in sync and in order of definition of
+ * btrfs_dev_stat_values.
+ */
+ return sysfs_emit(buf,
+ "write_errs %d\n"
+ "read_errs %d\n"
+ "flush_errs %d\n"
+ "corruption_errs %d\n"
+ "generation_errs %d\n",
+ btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
+ btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
+ btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
+ btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
+ btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
+}
+BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
+
+/*
+ * Information about one device.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
+ */
+static struct attribute *devid_attrs[] = {
+ BTRFS_ATTR_PTR(devid, error_stats),
+ BTRFS_ATTR_PTR(devid, fsid),
+ BTRFS_ATTR_PTR(devid, in_fs_metadata),
+ BTRFS_ATTR_PTR(devid, missing),
+ BTRFS_ATTR_PTR(devid, replace_target),
+ BTRFS_ATTR_PTR(devid, scrub_speed_max),
+ BTRFS_ATTR_PTR(devid, writeable),
+ NULL
+};
+ATTRIBUTE_GROUPS(devid);
+
+static void btrfs_release_devid_kobj(struct kobject *kobj)
+{
+ struct btrfs_device *device = container_of(kobj, struct btrfs_device,
+ devid_kobj);
+
+ memset(&device->devid_kobj, 0, sizeof(struct kobject));
+ complete(&device->kobj_unregister);
+}
+
+static const struct kobj_type devid_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = devid_groups,
+ .release = btrfs_release_devid_kobj,
+};
+
+int btrfs_sysfs_add_device(struct btrfs_device *device)
+{
+ int ret;
+ unsigned int nofs_flag;
+ struct kobject *devices_kobj;
+ struct kobject *devinfo_kobj;
+
+ /*
+ * Make sure we use the fs_info::fs_devices to fetch the kobjects even
+ * for the seed fs_devices
+ */
+ devices_kobj = device->fs_info->fs_devices->devices_kobj;
+ devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
+ ASSERT(devices_kobj);
+ ASSERT(devinfo_kobj);
+
+ nofs_flag = memalloc_nofs_save();
+
+ if (device->bdev) {
+ struct kobject *disk_kobj = bdev_kobj(device->bdev);
+
+ ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
+ if (ret) {
+ btrfs_warn(device->fs_info,
+ "creating sysfs device link for devid %llu failed: %d",
+ device->devid, ret);
+ goto out;
+ }
+ }
+
+ init_completion(&device->kobj_unregister);
+ ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
+ devinfo_kobj, "%llu", device->devid);
+ if (ret) {
+ kobject_put(&device->devid_kobj);
+ btrfs_warn(device->fs_info,
+ "devinfo init for devid %llu failed: %d",
+ device->devid, ret);
+ }
+
+out:
+ memalloc_nofs_restore(nofs_flag);
+ return ret;
+}
+
+static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
+{
+ int ret;
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *seed;
+
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ ret = btrfs_sysfs_add_device(device);
+ if (ret)
+ goto fail;
+ }
+
+ list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
+ list_for_each_entry(device, &seed->devices, dev_list) {
+ ret = btrfs_sysfs_add_device(device);
+ if (ret)
+ goto fail;
+ }
+ }
+
+ return 0;
+
+fail:
+ btrfs_sysfs_remove_fs_devices(fs_devices);
+ return ret;
+}
+
+void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
+{
+ int ret;
+
+ ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
+ if (ret)
+ pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
+ action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
+ &disk_to_dev(bdev->bd_disk)->kobj);
+}
+
+void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
+
+{
+ char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+
+ /*
+ * Sprouting changes fsid of the mounted filesystem, rename the fsid
+ * directory
+ */
+ snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
+ if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
+ btrfs_warn(fs_devices->fs_info,
+ "sysfs: failed to create fsid for sprout");
+}
+
+void btrfs_sysfs_update_devid(struct btrfs_device *device)
+{
+ char tmp[24];
+
+ snprintf(tmp, sizeof(tmp), "%llu", device->devid);
+
+ if (kobject_rename(&device->devid_kobj, tmp))
+ btrfs_warn(device->fs_devices->fs_info,
+ "sysfs: failed to update devid for %llu",
+ device->devid);
+}
+
+/* /sys/fs/btrfs/ entry */
+static struct kset *btrfs_kset;
+
+/*
+ * Creates:
+ * /sys/fs/btrfs/UUID
+ *
+ * Can be called by the device discovery thread.
+ */
+int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
+{
+ int error;
+
+ init_completion(&fs_devs->kobj_unregister);
+ fs_devs->fsid_kobj.kset = btrfs_kset;
+ error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
+ "%pU", fs_devs->fsid);
+ if (error) {
+ kobject_put(&fs_devs->fsid_kobj);
+ return error;
+ }
+
+ fs_devs->devices_kobj = kobject_create_and_add("devices",
+ &fs_devs->fsid_kobj);
+ if (!fs_devs->devices_kobj) {
+ btrfs_err(fs_devs->fs_info,
+ "failed to init sysfs device interface");
+ btrfs_sysfs_remove_fsid(fs_devs);
+ return -ENOMEM;
+ }
+
+ fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
+ &fs_devs->fsid_kobj);
+ if (!fs_devs->devinfo_kobj) {
+ btrfs_err(fs_devs->fs_info,
+ "failed to init sysfs devinfo kobject");
+ btrfs_sysfs_remove_fsid(fs_devs);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
+{
+ int error;
+ struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
+ struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
+
+ error = btrfs_sysfs_add_fs_devices(fs_devs);
+ if (error)
+ return error;
+
+ error = sysfs_create_files(fsid_kobj, btrfs_attrs);
+ if (error) {
+ btrfs_sysfs_remove_fs_devices(fs_devs);
+ return error;
+ }
+
+ error = sysfs_create_group(fsid_kobj,
+ &btrfs_feature_attr_group);
+ if (error)
+ goto failure;
+
+#ifdef CONFIG_BTRFS_DEBUG
+ fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
+ if (!fs_info->debug_kobj) {
+ error = -ENOMEM;
+ goto failure;
+ }
+
+ error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
+ if (error)
+ goto failure;
+#endif
+
+ /* Discard directory */
+ fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
+ if (!fs_info->discard_kobj) {
+ error = -ENOMEM;
+ goto failure;
+ }
+
+ error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
+ if (error)
+ goto failure;
+
+ error = addrm_unknown_feature_attrs(fs_info, true);
+ if (error)
+ goto failure;
+
+ error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
+ if (error)
+ goto failure;
+
+ fs_info->space_info_kobj = kobject_create_and_add("allocation",
+ fsid_kobj);
+ if (!fs_info->space_info_kobj) {
+ error = -ENOMEM;
+ goto failure;
+ }
+
+ error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
+ if (error)
+ goto failure;
+
+ return 0;
+failure:
+ btrfs_sysfs_remove_mounted(fs_info);
+ return error;
+}
+
+static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
+ bool enabled;
+
+ spin_lock(&fs_info->qgroup_lock);
+ enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
+ spin_unlock(&fs_info->qgroup_lock);
+
+ return sysfs_emit(buf, "%d\n", enabled);
+}
+BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
+
+static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
+ bool inconsistent;
+
+ spin_lock(&fs_info->qgroup_lock);
+ inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
+ spin_unlock(&fs_info->qgroup_lock);
+
+ return sysfs_emit(buf, "%d\n", inconsistent);
+}
+BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
+
+static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
+ u8 result;
+
+ spin_lock(&fs_info->qgroup_lock);
+ result = fs_info->qgroup_drop_subtree_thres;
+ spin_unlock(&fs_info->qgroup_lock);
+
+ return sysfs_emit(buf, "%d\n", result);
+}
+
+static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
+ struct kobj_attribute *a,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
+ u8 new_thres;
+ int ret;
+
+ ret = kstrtou8(buf, 10, &new_thres);
+ if (ret)
+ return -EINVAL;
+
+ if (new_thres > BTRFS_MAX_LEVEL)
+ return -EINVAL;
+
+ spin_lock(&fs_info->qgroup_lock);
+ fs_info->qgroup_drop_subtree_thres = new_thres;
+ spin_unlock(&fs_info->qgroup_lock);
+
+ return len;
+}
+BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
+ qgroup_drop_subtree_thres_store);
+
+/*
+ * Qgroups global info
+ *
+ * Path: /sys/fs/btrfs/<uuid>/qgroups/
+ */
+static struct attribute *qgroups_attrs[] = {
+ BTRFS_ATTR_PTR(qgroups, enabled),
+ BTRFS_ATTR_PTR(qgroups, inconsistent),
+ BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
+ NULL
+};
+ATTRIBUTE_GROUPS(qgroups);
+
+static void qgroups_release(struct kobject *kobj)
+{
+ kfree(kobj);
+}
+
+static const struct kobj_type qgroups_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = qgroups_groups,
+ .release = qgroups_release,
+};
+
+static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
+{
+ return to_fs_info(kobj->parent->parent);
+}
+
+#define QGROUP_ATTR(_member, _show_name) \
+static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj, \
+ struct kobj_attribute *a, \
+ char *buf) \
+{ \
+ struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
+ struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
+ struct btrfs_qgroup, kobj); \
+ return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf); \
+} \
+BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
+
+#define QGROUP_RSV_ATTR(_name, _type) \
+static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj, \
+ struct kobj_attribute *a, \
+ char *buf) \
+{ \
+ struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
+ struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
+ struct btrfs_qgroup, kobj); \
+ return btrfs_show_u64(&qgroup->rsv.values[_type], \
+ &fs_info->qgroup_lock, buf); \
+} \
+BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
+
+QGROUP_ATTR(rfer, referenced);
+QGROUP_ATTR(excl, exclusive);
+QGROUP_ATTR(max_rfer, max_referenced);
+QGROUP_ATTR(max_excl, max_exclusive);
+QGROUP_ATTR(lim_flags, limit_flags);
+QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
+QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
+QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
+
+/*
+ * Qgroup information.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
+ */
+static struct attribute *qgroup_attrs[] = {
+ BTRFS_ATTR_PTR(qgroup, referenced),
+ BTRFS_ATTR_PTR(qgroup, exclusive),
+ BTRFS_ATTR_PTR(qgroup, max_referenced),
+ BTRFS_ATTR_PTR(qgroup, max_exclusive),
+ BTRFS_ATTR_PTR(qgroup, limit_flags),
+ BTRFS_ATTR_PTR(qgroup, rsv_data),
+ BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
+ BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
+ NULL
+};
+ATTRIBUTE_GROUPS(qgroup);
+
+static void qgroup_release(struct kobject *kobj)
+{
+ struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
+
+ memset(&qgroup->kobj, 0, sizeof(*kobj));
+}
+
+static const struct kobj_type qgroup_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = qgroup_release,
+ .default_groups = qgroup_groups,
+};
+
+int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
+ struct btrfs_qgroup *qgroup)
+{
+ struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
+ int ret;
+
+ if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
+ return 0;
+ if (qgroup->kobj.state_initialized)
+ return 0;
+ if (!qgroups_kobj)
+ return -EINVAL;
+
+ ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
+ "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
+ btrfs_qgroup_subvolid(qgroup->qgroupid));
+ if (ret < 0)
+ kobject_put(&qgroup->kobj);
+
+ return ret;
+}
+
+void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_qgroup *qgroup;
+ struct btrfs_qgroup *next;
+
+ if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
+ return;
+
+ rbtree_postorder_for_each_entry_safe(qgroup, next,
+ &fs_info->qgroup_tree, node)
+ btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
+ if (fs_info->qgroups_kobj) {
+ kobject_del(fs_info->qgroups_kobj);
+ kobject_put(fs_info->qgroups_kobj);
+ fs_info->qgroups_kobj = NULL;
+ }
+}
+
+/* Called when qgroups get initialized, thus there is no need for locking */
+int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
+{
+ struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
+ struct btrfs_qgroup *qgroup;
+ struct btrfs_qgroup *next;
+ int ret = 0;
+
+ if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
+ return 0;
+
+ ASSERT(fsid_kobj);
+ if (fs_info->qgroups_kobj)
+ return 0;
+
+ fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
+ if (!fs_info->qgroups_kobj)
+ return -ENOMEM;
+
+ ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
+ fsid_kobj, "qgroups");
+ if (ret < 0)
+ goto out;
+
+ rbtree_postorder_for_each_entry_safe(qgroup, next,
+ &fs_info->qgroup_tree, node) {
+ ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
+ if (ret < 0)
+ goto out;
+ }
+
+out:
+ if (ret < 0)
+ btrfs_sysfs_del_qgroups(fs_info);
+ return ret;
+}
+
+void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
+ struct btrfs_qgroup *qgroup)
+{
+ if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
+ return;
+
+ if (qgroup->kobj.state_initialized) {
+ kobject_del(&qgroup->kobj);
+ kobject_put(&qgroup->kobj);
+ }
+}
+
+/*
+ * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
+ * values in superblock. Call after any changes to incompat/compat_ro flags
+ */
+void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
+{
+ struct kobject *fsid_kobj;
+ int ret;
+
+ if (!fs_info)
+ return;
+
+ fsid_kobj = &fs_info->fs_devices->fsid_kobj;
+ if (!fsid_kobj->state_initialized)
+ return;
+
+ ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
+ if (ret < 0)
+ btrfs_warn(fs_info,
+ "failed to update /sys/fs/btrfs/%pU/features: %d",
+ fs_info->fs_devices->fsid, ret);
+}
+
+int __init btrfs_init_sysfs(void)
+{
+ int ret;
+
+ btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
+ if (!btrfs_kset)
+ return -ENOMEM;
+
+ init_feature_attrs();
+ ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
+ if (ret)
+ goto out2;
+ ret = sysfs_merge_group(&btrfs_kset->kobj,
+ &btrfs_static_feature_attr_group);
+ if (ret)
+ goto out_remove_group;
+
+#ifdef CONFIG_BTRFS_DEBUG
+ ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
+ if (ret) {
+ sysfs_unmerge_group(&btrfs_kset->kobj,
+ &btrfs_static_feature_attr_group);
+ goto out_remove_group;
+ }
+#endif
+
+ return 0;
+
+out_remove_group:
+ sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
+out2:
+ kset_unregister(btrfs_kset);
+
+ return ret;
+}
+
+void __cold btrfs_exit_sysfs(void)
+{
+ sysfs_unmerge_group(&btrfs_kset->kobj,
+ &btrfs_static_feature_attr_group);
+ sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
+#ifdef CONFIG_BTRFS_DEBUG
+ sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
+#endif
+ kset_unregister(btrfs_kset);
+}