xref: /freebsd/sys/contrib/openzfs/module/zfs/dbuf_stats.c (revision 9d54812421274e490dc5f0fe4722ab8d35d9b258)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or https://opensource.org/licenses/CDDL-1.0.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 #include <sys/zfs_context.h>
23 #include <sys/dbuf.h>
24 #include <sys/dmu_objset.h>
25 
26 /*
27  * Calculate the index of the arc header for the state, disabled by default.
28  */
29 int zfs_dbuf_state_index = 0;
30 
31 /*
32  * ==========================================================================
33  * Dbuf Hash Read Routines
34  * ==========================================================================
35  */
36 typedef struct dbuf_stats_t {
37 	kmutex_t		lock;
38 	kstat_t			*kstat;
39 	dbuf_hash_table_t	*hash;
40 	int			idx;
41 } dbuf_stats_t;
42 
43 static dbuf_stats_t dbuf_stats_hash_table;
44 
45 static int
46 dbuf_stats_hash_table_headers(char *buf, size_t size)
47 {
48 	(void) snprintf(buf, size,
49 	    "%-96s | %-119s | %s\n"
50 	    "%-16s %-8s %-8s %-8s %-8s %-10s %-8s %-5s %-5s %-7s %3s | "
51 	    "%-5s %-5s %-9s %-6s %-8s %-12s "
52 	    "%-6s %-6s %-6s %-6s %-6s %-8s %-8s %-8s %-6s | "
53 	    "%-6s %-6s %-8s %-8s %-6s %-6s %-6s %-8s %-8s\n",
54 	    "dbuf", "arcbuf", "dnode", "pool", "objset", "object", "level",
55 	    "blkid", "offset", "dbsize", "meta", "state", "dbholds", "dbc",
56 	    "list", "atype", "flags", "count", "asize", "access",
57 	    "mru", "gmru", "mfu", "gmfu", "l2", "l2_dattr", "l2_asize",
58 	    "l2_comp", "aholds", "dtype", "btype", "data_bs", "meta_bs",
59 	    "bsize", "lvls", "dholds", "blocks", "dsize");
60 
61 	return (0);
62 }
63 
64 static int
65 __dbuf_stats_hash_table_data(char *buf, size_t size, dmu_buf_impl_t *db)
66 {
67 	arc_buf_info_t abi = { 0 };
68 	dmu_object_info_t doi = { 0 };
69 	dnode_t *dn = DB_DNODE(db);
70 	size_t nwritten;
71 
72 	if (db->db_buf)
73 		arc_buf_info(db->db_buf, &abi, zfs_dbuf_state_index);
74 
75 	__dmu_object_info_from_dnode(dn, &doi);
76 
77 	nwritten = snprintf(buf, size,
78 	    "%-16s %-8llu %-8lld %-8lld %-8lld %-10llu %-8llu %-5d %-5d "
79 	    "%-7lu %-3d | %-5d %-5d 0x%-7x %-6lu %-8llu %-12llu "
80 	    "%-6lu %-6lu %-6lu %-6lu %-6lu %-8llu %-8llu %-8d %-6lu | "
81 	    "%-6d %-6d %-8lu %-8lu %-6llu %-6lu %-6lu %-8llu %-8llu\n",
82 	    /* dmu_buf_impl_t */
83 	    spa_name(dn->dn_objset->os_spa),
84 	    (u_longlong_t)dmu_objset_id(db->db_objset),
85 	    (longlong_t)db->db.db_object,
86 	    (longlong_t)db->db_level,
87 	    (longlong_t)db->db_blkid,
88 	    (u_longlong_t)db->db.db_offset,
89 	    (u_longlong_t)db->db.db_size,
90 	    !!dbuf_is_metadata(db),
91 	    db->db_state,
92 	    (ulong_t)zfs_refcount_count(&db->db_holds),
93 	    multilist_link_active(&db->db_cache_link),
94 	    /* arc_buf_info_t */
95 	    abi.abi_state_type,
96 	    abi.abi_state_contents,
97 	    abi.abi_flags,
98 	    (ulong_t)abi.abi_bufcnt,
99 	    (u_longlong_t)abi.abi_size,
100 	    (u_longlong_t)abi.abi_access,
101 	    (ulong_t)abi.abi_mru_hits,
102 	    (ulong_t)abi.abi_mru_ghost_hits,
103 	    (ulong_t)abi.abi_mfu_hits,
104 	    (ulong_t)abi.abi_mfu_ghost_hits,
105 	    (ulong_t)abi.abi_l2arc_hits,
106 	    (u_longlong_t)abi.abi_l2arc_dattr,
107 	    (u_longlong_t)abi.abi_l2arc_asize,
108 	    abi.abi_l2arc_compress,
109 	    (ulong_t)abi.abi_holds,
110 	    /* dmu_object_info_t */
111 	    doi.doi_type,
112 	    doi.doi_bonus_type,
113 	    (ulong_t)doi.doi_data_block_size,
114 	    (ulong_t)doi.doi_metadata_block_size,
115 	    (u_longlong_t)doi.doi_bonus_size,
116 	    (ulong_t)doi.doi_indirection,
117 	    (ulong_t)zfs_refcount_count(&dn->dn_holds),
118 	    (u_longlong_t)doi.doi_fill_count,
119 	    (u_longlong_t)doi.doi_max_offset);
120 
121 	if (nwritten >= size)
122 		return (size);
123 
124 	return (nwritten + 1);
125 }
126 
127 static int
128 dbuf_stats_hash_table_data(char *buf, size_t size, void *data)
129 {
130 	dbuf_stats_t *dsh = (dbuf_stats_t *)data;
131 	dbuf_hash_table_t *h = dsh->hash;
132 	dmu_buf_impl_t *db;
133 	int length, error = 0;
134 
135 	ASSERT3S(dsh->idx, >=, 0);
136 	ASSERT3S(dsh->idx, <=, h->hash_table_mask);
137 	if (size)
138 		buf[0] = 0;
139 
140 	rw_enter(DBUF_HASH_RWLOCK(h, dsh->idx), RW_READER);
141 	for (db = h->hash_table[dsh->idx]; db != NULL; db = db->db_hash_next) {
142 		/*
143 		 * Returning ENOMEM will cause the data and header functions
144 		 * to be called with a larger scratch buffers.
145 		 */
146 		if (size < 512) {
147 			error = SET_ERROR(ENOMEM);
148 			break;
149 		}
150 
151 		mutex_enter(&db->db_mtx);
152 
153 		if (db->db_state != DB_EVICTING) {
154 			length = __dbuf_stats_hash_table_data(buf, size, db);
155 			buf += length;
156 			size -= length;
157 		}
158 
159 		mutex_exit(&db->db_mtx);
160 	}
161 	rw_exit(DBUF_HASH_RWLOCK(h, dsh->idx));
162 
163 	return (error);
164 }
165 
166 static void *
167 dbuf_stats_hash_table_addr(kstat_t *ksp, loff_t n)
168 {
169 	dbuf_stats_t *dsh = ksp->ks_private;
170 
171 	ASSERT(MUTEX_HELD(&dsh->lock));
172 
173 	if (n <= dsh->hash->hash_table_mask) {
174 		dsh->idx = n;
175 		return (dsh);
176 	}
177 
178 	return (NULL);
179 }
180 
181 static void
182 dbuf_stats_hash_table_init(dbuf_hash_table_t *hash)
183 {
184 	dbuf_stats_t *dsh = &dbuf_stats_hash_table;
185 	kstat_t *ksp;
186 
187 	mutex_init(&dsh->lock, NULL, MUTEX_DEFAULT, NULL);
188 	dsh->hash = hash;
189 
190 	ksp = kstat_create("zfs", 0, "dbufs", "misc",
191 	    KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);
192 	dsh->kstat = ksp;
193 
194 	if (ksp) {
195 		ksp->ks_lock = &dsh->lock;
196 		ksp->ks_ndata = UINT32_MAX;
197 		ksp->ks_private = dsh;
198 		kstat_set_raw_ops(ksp, dbuf_stats_hash_table_headers,
199 		    dbuf_stats_hash_table_data, dbuf_stats_hash_table_addr);
200 		kstat_install(ksp);
201 	}
202 }
203 
204 static void
205 dbuf_stats_hash_table_destroy(void)
206 {
207 	dbuf_stats_t *dsh = &dbuf_stats_hash_table;
208 	kstat_t *ksp;
209 
210 	ksp = dsh->kstat;
211 	if (ksp)
212 		kstat_delete(ksp);
213 
214 	mutex_destroy(&dsh->lock);
215 }
216 
217 void
218 dbuf_stats_init(dbuf_hash_table_t *hash)
219 {
220 	dbuf_stats_hash_table_init(hash);
221 }
222 
223 void
224 dbuf_stats_destroy(void)
225 {
226 	dbuf_stats_hash_table_destroy();
227 }
228 
229 ZFS_MODULE_PARAM(zfs, zfs_, dbuf_state_index, INT, ZMOD_RW,
230 	"Calculate arc header index");
231