KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 484 insertions, 0 deletions

diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
new file mode 100644
index 000000000..83c270bce
--- /dev/null
+++ b/net/ceph/debugfs.c
@@ -0,0 +1,484 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/mon_client.h>
+#include <linux/ceph/auth.h>
+#include <linux/ceph/debugfs.h>
+
+#ifdef CONFIG_DEBUG_FS
+
+/*
+ * Implement /sys/kernel/debug/ceph fun
+ *
+ * /sys/kernel/debug/ceph/client*  - an instance of the ceph client
+ *      .../osdmap      - current osdmap
+ *      .../monmap      - current monmap
+ *      .../osdc        - active osd requests
+ *      .../monc        - mon client state
+ *      .../client_options - libceph-only (i.e. not rbd or cephfs) options
+ *      .../dentry_lru  - dump contents of dentry lru
+ *      .../caps        - expose cap (reservation) stats
+ *      .../bdi         - symlink to ../../bdi/something
+ */
+
+static struct dentry *ceph_debugfs_dir;
+
+static int monmap_show(struct seq_file *s, void *p)
+{
+	int i;
+	struct ceph_client *client = s->private;
+
+	mutex_lock(&client->monc.mutex);
+	if (client->monc.monmap == NULL)
+		goto out_unlock;
+
+	seq_printf(s, "epoch %d\n", client->monc.monmap->epoch);
+	for (i = 0; i < client->monc.monmap->num_mon; i++) {
+		struct ceph_entity_inst *inst =
+			&client->monc.monmap->mon_inst[i];
+
+		seq_printf(s, "\t%s%lld\t%s\n",
+			   ENTITY_NAME(inst->name),
+			   ceph_pr_addr(&inst->addr));
+	}
+
+out_unlock:
+	mutex_unlock(&client->monc.mutex);
+	return 0;
+}
+
+static int osdmap_show(struct seq_file *s, void *p)
+{
+	int i;
+	struct ceph_client *client = s->private;
+	struct ceph_osd_client *osdc = &client->osdc;
+	struct ceph_osdmap *map;
+	struct rb_node *n;
+
+	down_read(&osdc->lock);
+	map = osdc->osdmap;
+	if (map == NULL)
+		goto out_unlock;
+
+	seq_printf(s, "epoch %u barrier %u flags 0x%x\n", map->epoch,
+			osdc->epoch_barrier, map->flags);
+
+	for (n = rb_first(&map->pg_pools); n; n = rb_next(n)) {
+		struct ceph_pg_pool_info *pi =
+			rb_entry(n, struct ceph_pg_pool_info, node);
+
+		seq_printf(s, "pool %lld '%s' type %d size %d min_size %d pg_num %u pg_num_mask %d flags 0x%llx lfor %u read_tier %lld write_tier %lld\n",
+			   pi->id, pi->name, pi->type, pi->size, pi->min_size,
+			   pi->pg_num, pi->pg_num_mask, pi->flags,
+			   pi->last_force_request_resend, pi->read_tier,
+			   pi->write_tier);
+	}
+	for (i = 0; i < map->max_osd; i++) {
+		struct ceph_entity_addr *addr = &map->osd_addr[i];
+		u32 state = map->osd_state[i];
+		char sb[64];
+
+		seq_printf(s, "osd%d\t%s\t%3d%%\t(%s)\t%3d%%\t%2d\n",
+			   i, ceph_pr_addr(addr),
+			   ((map->osd_weight[i]*100) >> 16),
+			   ceph_osdmap_state_str(sb, sizeof(sb), state),
+			   ((ceph_get_primary_affinity(map, i)*100) >> 16),
+			   ceph_get_crush_locality(map, i,
+					   &client->options->crush_locs));
+	}
+	for (n = rb_first(&map->pg_temp); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "pg_temp %llu.%x [", pg->pgid.pool,
+			   pg->pgid.seed);
+		for (i = 0; i < pg->pg_temp.len; i++)
+			seq_printf(s, "%s%d", (i == 0 ? "" : ","),
+				   pg->pg_temp.osds[i]);
+		seq_printf(s, "]\n");
+	}
+	for (n = rb_first(&map->primary_temp); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "primary_temp %llu.%x %d\n", pg->pgid.pool,
+			   pg->pgid.seed, pg->primary_temp.osd);
+	}
+	for (n = rb_first(&map->pg_upmap); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "pg_upmap %llu.%x [", pg->pgid.pool,
+			   pg->pgid.seed);
+		for (i = 0; i < pg->pg_upmap.len; i++)
+			seq_printf(s, "%s%d", (i == 0 ? "" : ","),
+				   pg->pg_upmap.osds[i]);
+		seq_printf(s, "]\n");
+	}
+	for (n = rb_first(&map->pg_upmap_items); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "pg_upmap_items %llu.%x [", pg->pgid.pool,
+			   pg->pgid.seed);
+		for (i = 0; i < pg->pg_upmap_items.len; i++)
+			seq_printf(s, "%s%d->%d", (i == 0 ? "" : ","),
+				   pg->pg_upmap_items.from_to[i][0],
+				   pg->pg_upmap_items.from_to[i][1]);
+		seq_printf(s, "]\n");
+	}
+
+out_unlock:
+	up_read(&osdc->lock);
+	return 0;
+}
+
+static int monc_show(struct seq_file *s, void *p)
+{
+	struct ceph_client *client = s->private;
+	struct ceph_mon_generic_request *req;
+	struct ceph_mon_client *monc = &client->monc;
+	struct rb_node *rp;
+	int i;
+
+	mutex_lock(&monc->mutex);
+
+	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
+		seq_printf(s, "have %s %u", ceph_sub_str[i],
+			   monc->subs[i].have);
+		if (monc->subs[i].want)
+			seq_printf(s, " want %llu%s",
+				   le64_to_cpu(monc->subs[i].item.start),
+				   (monc->subs[i].item.flags &
+					CEPH_SUBSCRIBE_ONETIME ?  "" : "+"));
+		seq_putc(s, '\n');
+	}
+	seq_printf(s, "fs_cluster_id %d\n", monc->fs_cluster_id);
+
+	for (rp = rb_first(&monc->generic_request_tree); rp; rp = rb_next(rp)) {
+		__u16 op;
+		req = rb_entry(rp, struct ceph_mon_generic_request, node);
+		op = le16_to_cpu(req->request->hdr.type);
+		if (op == CEPH_MSG_STATFS)
+			seq_printf(s, "%llu statfs\n", req->tid);
+		else if (op == CEPH_MSG_MON_GET_VERSION)
+			seq_printf(s, "%llu mon_get_version", req->tid);
+		else
+			seq_printf(s, "%llu unknown\n", req->tid);
+	}
+
+	mutex_unlock(&monc->mutex);
+	return 0;
+}
+
+static void dump_spgid(struct seq_file *s, const struct ceph_spg *spgid)
+{
+	seq_printf(s, "%llu.%x", spgid->pgid.pool, spgid->pgid.seed);
+	if (spgid->shard != CEPH_SPG_NOSHARD)
+		seq_printf(s, "s%d", spgid->shard);
+}
+
+static void dump_target(struct seq_file *s, struct ceph_osd_request_target *t)
+{
+	int i;
+
+	seq_printf(s, "osd%d\t%llu.%x\t", t->osd, t->pgid.pool, t->pgid.seed);
+	dump_spgid(s, &t->spgid);
+	seq_puts(s, "\t[");
+	for (i = 0; i < t->up.size; i++)
+		seq_printf(s, "%s%d", (!i ? "" : ","), t->up.osds[i]);
+	seq_printf(s, "]/%d\t[", t->up.primary);
+	for (i = 0; i < t->acting.size; i++)
+		seq_printf(s, "%s%d", (!i ? "" : ","), t->acting.osds[i]);
+	seq_printf(s, "]/%d\te%u\t", t->acting.primary, t->epoch);
+	if (t->target_oloc.pool_ns) {
+		seq_printf(s, "%*pE/%*pE\t0x%x",
+			(int)t->target_oloc.pool_ns->len,
+			t->target_oloc.pool_ns->str,
+			t->target_oid.name_len, t->target_oid.name, t->flags);
+	} else {
+		seq_printf(s, "%*pE\t0x%x", t->target_oid.name_len,
+			t->target_oid.name, t->flags);
+	}
+	if (t->paused)
+		seq_puts(s, "\tP");
+}
+
+static void dump_request(struct seq_file *s, struct ceph_osd_request *req)
+{
+	int i;
+
+	seq_printf(s, "%llu\t", req->r_tid);
+	dump_target(s, &req->r_t);
+
+	seq_printf(s, "\t%d", req->r_attempts);
+
+	for (i = 0; i < req->r_num_ops; i++) {
+		struct ceph_osd_req_op *op = &req->r_ops[i];
+
+		seq_printf(s, "%s%s", (i == 0 ? "\t" : ","),
+			   ceph_osd_op_name(op->op));
+		if (op->op == CEPH_OSD_OP_WATCH)
+			seq_printf(s, "-%s",
+				   ceph_osd_watch_op_name(op->watch.op));
+		else if (op->op == CEPH_OSD_OP_CALL)
+			seq_printf(s, "-%s/%s", op->cls.class_name,
+				   op->cls.method_name);
+	}
+
+	seq_putc(s, '\n');
+}
+
+static void dump_requests(struct seq_file *s, struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	mutex_lock(&osd->lock);
+	for (n = rb_first(&osd->o_requests); n; n = rb_next(n)) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+
+		dump_request(s, req);
+	}
+
+	mutex_unlock(&osd->lock);
+}
+
+static void dump_linger_request(struct seq_file *s,
+				struct ceph_osd_linger_request *lreq)
+{
+	seq_printf(s, "%llu\t", lreq->linger_id);
+	dump_target(s, &lreq->t);
+
+	seq_printf(s, "\t%u\t%s%s/%d\n", lreq->register_gen,
+		   lreq->is_watch ? "W" : "N", lreq->committed ? "C" : "",
+		   lreq->last_error);
+}
+
+static void dump_linger_requests(struct seq_file *s, struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	mutex_lock(&osd->lock);
+	for (n = rb_first(&osd->o_linger_requests); n; n = rb_next(n)) {
+		struct ceph_osd_linger_request *lreq =
+		    rb_entry(n, struct ceph_osd_linger_request, node);
+
+		dump_linger_request(s, lreq);
+	}
+
+	mutex_unlock(&osd->lock);
+}
+
+static void dump_snapid(struct seq_file *s, u64 snapid)
+{
+	if (snapid == CEPH_NOSNAP)
+		seq_puts(s, "head");
+	else if (snapid == CEPH_SNAPDIR)
+		seq_puts(s, "snapdir");
+	else
+		seq_printf(s, "%llx", snapid);
+}
+
+static void dump_name_escaped(struct seq_file *s, unsigned char *name,
+			      size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; i++) {
+		if (name[i] == '%' || name[i] == ':' || name[i] == '/' ||
+		    name[i] < 32 || name[i] >= 127) {
+			seq_printf(s, "%%%02x", name[i]);
+		} else {
+			seq_putc(s, name[i]);
+		}
+	}
+}
+
+static void dump_hoid(struct seq_file *s, const struct ceph_hobject_id *hoid)
+{
+	if (hoid->snapid == 0 && hoid->hash == 0 && !hoid->is_max &&
+	    hoid->pool == S64_MIN) {
+		seq_puts(s, "MIN");
+		return;
+	}
+	if (hoid->is_max) {
+		seq_puts(s, "MAX");
+		return;
+	}
+	seq_printf(s, "%lld:%08x:", hoid->pool, hoid->hash_reverse_bits);
+	dump_name_escaped(s, hoid->nspace, hoid->nspace_len);
+	seq_putc(s, ':');
+	dump_name_escaped(s, hoid->key, hoid->key_len);
+	seq_putc(s, ':');
+	dump_name_escaped(s, hoid->oid, hoid->oid_len);
+	seq_putc(s, ':');
+	dump_snapid(s, hoid->snapid);
+}
+
+static void dump_backoffs(struct seq_file *s, struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	mutex_lock(&osd->lock);
+	for (n = rb_first(&osd->o_backoffs_by_id); n; n = rb_next(n)) {
+		struct ceph_osd_backoff *backoff =
+		    rb_entry(n, struct ceph_osd_backoff, id_node);
+
+		seq_printf(s, "osd%d\t", osd->o_osd);
+		dump_spgid(s, &backoff->spgid);
+		seq_printf(s, "\t%llu\t", backoff->id);
+		dump_hoid(s, backoff->begin);
+		seq_putc(s, '\t');
+		dump_hoid(s, backoff->end);
+		seq_putc(s, '\n');
+	}
+
+	mutex_unlock(&osd->lock);
+}
+
+static int osdc_show(struct seq_file *s, void *pp)
+{
+	struct ceph_client *client = s->private;
+	struct ceph_osd_client *osdc = &client->osdc;
+	struct rb_node *n;
+
+	down_read(&osdc->lock);
+	seq_printf(s, "REQUESTS %d homeless %d\n",
+		   atomic_read(&osdc->num_requests),
+		   atomic_read(&osdc->num_homeless));
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		dump_requests(s, osd);
+	}
+	dump_requests(s, &osdc->homeless_osd);
+
+	seq_puts(s, "LINGER REQUESTS\n");
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		dump_linger_requests(s, osd);
+	}
+	dump_linger_requests(s, &osdc->homeless_osd);
+
+	seq_puts(s, "BACKOFFS\n");
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		dump_backoffs(s, osd);
+	}
+
+	up_read(&osdc->lock);
+	return 0;
+}
+
+static int client_options_show(struct seq_file *s, void *p)
+{
+	struct ceph_client *client = s->private;
+	int ret;
+
+	ret = ceph_print_client_options(s, client, true);
+	if (ret)
+		return ret;
+
+	seq_putc(s, '\n');
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(monmap);
+DEFINE_SHOW_ATTRIBUTE(osdmap);
+DEFINE_SHOW_ATTRIBUTE(monc);
+DEFINE_SHOW_ATTRIBUTE(osdc);
+DEFINE_SHOW_ATTRIBUTE(client_options);
+
+void __init ceph_debugfs_init(void)
+{
+	ceph_debugfs_dir = debugfs_create_dir("ceph", NULL);
+}
+
+void ceph_debugfs_cleanup(void)
+{
+	debugfs_remove(ceph_debugfs_dir);
+}
+
+void ceph_debugfs_client_init(struct ceph_client *client)
+{
+	char name[80];
+
+	snprintf(name, sizeof(name), "%pU.client%lld", &client->fsid,
+		 client->monc.auth->global_id);
+
+	dout("ceph_debugfs_client_init %p %s\n", client, name);
+
+	client->debugfs_dir = debugfs_create_dir(name, ceph_debugfs_dir);
+
+	client->monc.debugfs_file = debugfs_create_file("monc",
+						      0400,
+						      client->debugfs_dir,
+						      client,
+						      &monc_fops);
+
+	client->osdc.debugfs_file = debugfs_create_file("osdc",
+						      0400,
+						      client->debugfs_dir,
+						      client,
+						      &osdc_fops);
+
+	client->debugfs_monmap = debugfs_create_file("monmap",
+					0400,
+					client->debugfs_dir,
+					client,
+					&monmap_fops);
+
+	client->debugfs_osdmap = debugfs_create_file("osdmap",
+					0400,
+					client->debugfs_dir,
+					client,
+					&osdmap_fops);
+
+	client->debugfs_options = debugfs_create_file("client_options",
+					0400,
+					client->debugfs_dir,
+					client,
+					&client_options_fops);
+}
+
+void ceph_debugfs_client_cleanup(struct ceph_client *client)
+{
+	dout("ceph_debugfs_client_cleanup %p\n", client);
+	debugfs_remove(client->debugfs_options);
+	debugfs_remove(client->debugfs_osdmap);
+	debugfs_remove(client->debugfs_monmap);
+	debugfs_remove(client->osdc.debugfs_file);
+	debugfs_remove(client->monc.debugfs_file);
+	debugfs_remove(client->debugfs_dir);
+}
+
+#else  /* CONFIG_DEBUG_FS */
+
+void __init ceph_debugfs_init(void)
+{
+}
+
+void ceph_debugfs_cleanup(void)
+{
+}
+
+void ceph_debugfs_client_init(struct ceph_client *client)
+{
+}
+
+void ceph_debugfs_client_cleanup(struct ceph_client *client)
+{
+}
+
+#endif  /* CONFIG_DEBUG_FS */