mdsmap.c

  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/ceph/ceph_debug.h>
  3
  4#include <linux/bug.h>
  5#include <linux/err.h>
  6#include <linux/random.h>
  7#include <linux/slab.h>
  8#include <linux/types.h>
  9
 10#include <linux/ceph/messenger.h>
 11#include <linux/ceph/decode.h>
 12
 13#include "mdsmap.h"
 14#include "mds_client.h"
 15#include "super.h"
 16
 17#define CEPH_MDS_IS_READY(i, ignore_laggy) \
 18	(m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
 19
 20static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 21{
 22	int n = 0;
 23	int i, j;
 24
 25	/* count */
 26	for (i = 0; i < m->possible_max_rank; i++)
 27		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 28			n++;
 29	if (n == 0)
 30		return -1;
 31
 32	/* pick */
 33	n = get_random_u32_below(n);
 34	for (j = 0, i = 0; i < m->possible_max_rank; i++) {
 35		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 36			j++;
 37		if (j > n)
 38			break;
 39	}
 40
 41	return i;
 42}
 43
 44/*
 45 * choose a random mds that is "up" (i.e. has a state > 0), or -1.
 46 */
 47int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
 48{
 49	int mds;
 50
 51	mds = __mdsmap_get_random_mds(m, false);
 52	if (mds == m->possible_max_rank || mds == -1)
 53		mds = __mdsmap_get_random_mds(m, true);
 54
 55	return mds == m->possible_max_rank ? -1 : mds;
 56}
 57
 58#define __decode_and_drop_type(p, end, type, bad)		\
 59	do {							\
 60		if (*p + sizeof(type) > end)			\
 61			goto bad;				\
 62		*p += sizeof(type);				\
 63	} while (0)
 64
 65#define __decode_and_drop_set(p, end, type, bad)		\
 66	do {							\
 67		u32 n;						\
 68		size_t need;					\
 69		ceph_decode_32_safe(p, end, n, bad);		\
 70		need = sizeof(type) * n;			\
 71		ceph_decode_need(p, end, need, bad);		\
 72		*p += need;					\
 73	} while (0)
 74
 75#define __decode_and_drop_map(p, end, ktype, vtype, bad)	\
 76	do {							\
 77		u32 n;						\
 78		size_t need;					\
 79		ceph_decode_32_safe(p, end, n, bad);		\
 80		need = (sizeof(ktype) + sizeof(vtype)) * n;	\
 81		ceph_decode_need(p, end, need, bad);		\
 82		*p += need;					\
 83	} while (0)
 84
 85
 86static int __decode_and_drop_compat_set(void **p, void* end)
 87{
 88	int i;
 89	/* compat, ro_compat, incompat*/
 90	for (i = 0; i < 3; i++) {
 91		u32 n;
 92		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 93		/* mask */
 94		*p += sizeof(u64);
 95		/* names (map<u64, string>) */
 96		n = ceph_decode_32(p);
 97		while (n-- > 0) {
 98			u32 len;
 99			ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
100					 bad);
101			*p += sizeof(u64);
102			len = ceph_decode_32(p);
103			ceph_decode_need(p, end, len, bad);
104			*p += len;
105		}
106	}
107	return 0;
108bad:
109	return -1;
110}
111
112/*
113 * Decode an MDS map
114 *
115 * Ignore any fields we don't care about (there are quite a few of
116 * them).
117 */
118struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p,
119				       void *end, bool msgr2)
120{
121	struct ceph_client *cl = mdsc->fsc->client;
122	struct ceph_mdsmap *m;
123	const void *start = *p;
124	int i, j, n;
125	int err;
126	u8 mdsmap_v;
127	u16 mdsmap_ev;
128	u32 target;
129
130	m = kzalloc(sizeof(*m), GFP_NOFS);
131	if (!m)
132		return ERR_PTR(-ENOMEM);
133
134	ceph_decode_need(p, end, 1 + 1, bad);
135	mdsmap_v = ceph_decode_8(p);
136	*p += sizeof(u8);			/* mdsmap_cv */
137	if (mdsmap_v >= 4) {
138	       u32 mdsmap_len;
139	       ceph_decode_32_safe(p, end, mdsmap_len, bad);
140	       if (end < *p + mdsmap_len)
141		       goto bad;
142	       end = *p + mdsmap_len;
143	}
144
145	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
146	m->m_epoch = ceph_decode_32(p);
147	m->m_client_epoch = ceph_decode_32(p);
148	m->m_last_failure = ceph_decode_32(p);
149	m->m_root = ceph_decode_32(p);
150	m->m_session_timeout = ceph_decode_32(p);
151	m->m_session_autoclose = ceph_decode_32(p);
152	m->m_max_file_size = ceph_decode_64(p);
153	m->m_max_mds = ceph_decode_32(p);
154
155	/*
156	 * pick out the active nodes as the m_num_active_mds, the
157	 * m_num_active_mds maybe larger than m_max_mds when decreasing
158	 * the max_mds in cluster side, in other case it should less
159	 * than or equal to m_max_mds.
160	 */
161	m->m_num_active_mds = n = ceph_decode_32(p);
162
163	/*
164	 * the possible max rank, it maybe larger than the m_num_active_mds,
165	 * for example if the mds_max == 2 in the cluster, when the MDS(0)
166	 * was laggy and being replaced by a new MDS, we will temporarily
167	 * receive a new mds map with n_num_mds == 1 and the active MDS(1),
168	 * and the mds rank >= m_num_active_mds.
169	 */
170	m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);
171
172	m->m_info = kcalloc(m->possible_max_rank, sizeof(*m->m_info), GFP_NOFS);
173	if (!m->m_info)
174		goto nomem;
175
176	/* pick out active nodes from mds_info (state > 0) */
177	for (i = 0; i < n; i++) {
178		u64 global_id;
179		u32 namelen;
180		s32 mds, inc, state;
181		u8 info_v;
182		void *info_end = NULL;
183		struct ceph_entity_addr addr;
184		u32 num_export_targets;
185		void *pexport_targets = NULL;
186		struct ceph_timespec laggy_since;
187		struct ceph_mds_info *info;
188		bool laggy;
189
190		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
191		global_id = ceph_decode_64(p);
192		info_v= ceph_decode_8(p);
193		if (info_v >= 4) {
194			u32 info_len;
195			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
196			*p += sizeof(u8);	/* info_cv */
197			info_len = ceph_decode_32(p);
198			info_end = *p + info_len;
199			if (info_end > end)
200				goto bad;
201		}
202
203		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
204		*p += sizeof(u64);
205		namelen = ceph_decode_32(p);  /* skip mds name */
206		*p += namelen;
207
208		ceph_decode_32_safe(p, end, mds, bad);
209		ceph_decode_32_safe(p, end, inc, bad);
210		ceph_decode_32_safe(p, end, state, bad);
211		*p += sizeof(u64);		/* state_seq */
212		if (info_v >= 8)
213			err = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
214		else
215			err = ceph_decode_entity_addr(p, end, &addr);
216		if (err)
217			goto corrupt;
218
219		ceph_decode_copy_safe(p, end, &laggy_since, sizeof(laggy_since),
220				      bad);
221		laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
222		*p += sizeof(u32);
223		ceph_decode_32_safe(p, end, namelen, bad);
224		*p += namelen;
225		if (info_v >= 2) {
226			ceph_decode_32_safe(p, end, num_export_targets, bad);
227			pexport_targets = *p;
228			*p += num_export_targets * sizeof(u32);
229		} else {
230			num_export_targets = 0;
231		}
232
233		if (info_end && *p != info_end) {
234			if (*p > info_end)
235				goto bad;
236			*p = info_end;
237		}
238
239		doutc(cl, "%d/%d %lld mds%d.%d %s %s%s\n", i+1, n, global_id,
240		      mds, inc, ceph_pr_addr(&addr),
241		      ceph_mds_state_name(state), laggy ? "(laggy)" : "");
242
243		if (mds < 0 || mds >= m->possible_max_rank) {
244			pr_warn_client(cl, "got incorrect mds(%d)\n", mds);
245			continue;
246		}
247
248		if (state <= 0) {
249			doutc(cl, "got incorrect state(%s)\n",
250			      ceph_mds_state_name(state));
251			continue;
252		}
253
254		info = &m->m_info[mds];
255		info->global_id = global_id;
256		info->state = state;
257		info->addr = addr;
258		info->laggy = laggy;
259		info->num_export_targets = num_export_targets;
260		if (num_export_targets) {
261			info->export_targets = kcalloc(num_export_targets,
262						       sizeof(u32), GFP_NOFS);
263			if (!info->export_targets)
264				goto nomem;
265			for (j = 0; j < num_export_targets; j++) {
266				target = ceph_decode_32(&pexport_targets);
267				info->export_targets[j] = target;
268			}
269		} else {
270			info->export_targets = NULL;
271		}
272	}
273
274	/* pg_pools */
275	ceph_decode_32_safe(p, end, n, bad);
276	m->m_num_data_pg_pools = n;
277	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
278	if (!m->m_data_pg_pools)
279		goto nomem;
280	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
281	for (i = 0; i < n; i++)
282		m->m_data_pg_pools[i] = ceph_decode_64(p);
283	m->m_cas_pg_pool = ceph_decode_64(p);
284	m->m_enabled = m->m_epoch > 1;
285
286	mdsmap_ev = 1;
287	if (mdsmap_v >= 2) {
288		ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
289	}
290	if (mdsmap_ev >= 3) {
291		if (__decode_and_drop_compat_set(p, end) < 0)
292			goto bad_ext;
293	}
294	/* metadata_pool */
295	if (mdsmap_ev < 5) {
296		__decode_and_drop_type(p, end, u32, bad_ext);
297	} else {
298		__decode_and_drop_type(p, end, u64, bad_ext);
299	}
300
301	/* created + modified + tableserver */
302	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
303	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
304	__decode_and_drop_type(p, end, u32, bad_ext);
305
306	/* in */
307	{
308		int num_laggy = 0;
309		ceph_decode_32_safe(p, end, n, bad_ext);
310		ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
311
312		for (i = 0; i < n; i++) {
313			s32 mds = ceph_decode_32(p);
314			if (mds >= 0 && mds < m->possible_max_rank) {
315				if (m->m_info[mds].laggy)
316					num_laggy++;
317			}
318		}
319		m->m_num_laggy = num_laggy;
320
321		if (n > m->possible_max_rank) {
322			void *new_m_info = krealloc(m->m_info,
323						    n * sizeof(*m->m_info),
324						    GFP_NOFS | __GFP_ZERO);
325			if (!new_m_info)
326				goto nomem;
327			m->m_info = new_m_info;
328		}
329		m->possible_max_rank = n;
330	}
331
332	/* inc */
333	__decode_and_drop_map(p, end, u32, u32, bad_ext);
334	/* up */
335	__decode_and_drop_map(p, end, u32, u64, bad_ext);
336	/* failed */
337	__decode_and_drop_set(p, end, u32, bad_ext);
338	/* stopped */
339	__decode_and_drop_set(p, end, u32, bad_ext);
340
341	if (mdsmap_ev >= 4) {
342		/* last_failure_osd_epoch */
343		__decode_and_drop_type(p, end, u32, bad_ext);
344	}
345	if (mdsmap_ev >= 6) {
346		/* ever_allowed_snaps */
347		__decode_and_drop_type(p, end, u8, bad_ext);
348		/* explicitly_allowed_snaps */
349		__decode_and_drop_type(p, end, u8, bad_ext);
350	}
351	if (mdsmap_ev >= 7) {
352		/* inline_data_enabled */
353		__decode_and_drop_type(p, end, u8, bad_ext);
354	}
355	if (mdsmap_ev >= 8) {
356		size_t fsname_len;
357
358		/* enabled */
359		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
360
361		/* fs_name */
362		m->m_fs_name = ceph_extract_encoded_string(p, end,
363							   &fsname_len,
364							   GFP_NOFS);
365		if (IS_ERR(m->m_fs_name)) {
366			m->m_fs_name = NULL;
367			goto nomem;
368		}
369
370		/* validate fsname against mds_namespace */
371		if (!namespace_equals(mdsc->fsc->mount_options, m->m_fs_name,
372				      fsname_len)) {
373			pr_warn_client(cl, "fsname %s doesn't match mds_namespace %s\n",
374				       m->m_fs_name,
375				       mdsc->fsc->mount_options->mds_namespace);
376			goto bad;
377		}
378	} else {
379		m->m_enabled = false;
380		m->m_fs_name = kstrdup(CEPH_OLD_FS_NAME, GFP_NOFS);
381		if (!m->m_fs_name)
382			goto nomem;
383	}
384	/* damaged */
385	if (mdsmap_ev >= 9) {
386		size_t need;
387		ceph_decode_32_safe(p, end, n, bad_ext);
388		need = sizeof(u32) * n;
389		ceph_decode_need(p, end, need, bad_ext);
390		*p += need;
391		m->m_damaged = n > 0;
392	} else {
393		m->m_damaged = false;
394	}
395	if (mdsmap_ev >= 17) {
396		/* balancer */
397		ceph_decode_skip_string(p, end, bad_ext);
398		/* standby_count_wanted */
399		ceph_decode_skip_32(p, end, bad_ext);
400		/* old_max_mds */
401		ceph_decode_skip_32(p, end, bad_ext);
402		/* min_compat_client */
403		ceph_decode_skip_8(p, end, bad_ext);
404		/* required_client_features */
405		ceph_decode_skip_set(p, end, 64, bad_ext);
406		/* bal_rank_mask */
407		ceph_decode_skip_string(p, end, bad_ext);
408	}
409	if (mdsmap_ev >= 18) {
410		ceph_decode_64_safe(p, end, m->m_max_xattr_size, bad_ext);
411	}
412bad_ext:
413	doutc(cl, "m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
414	      !!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
415	*p = end;
416	doutc(cl, "success epoch %u\n", m->m_epoch);
417	return m;
418nomem:
419	err = -ENOMEM;
420	goto out_err;
421corrupt:
422	pr_err_client(cl, "corrupt mdsmap\n");
423	print_hex_dump(KERN_DEBUG, "mdsmap: ",
424		       DUMP_PREFIX_OFFSET, 16, 1,
425		       start, end - start, true);
426out_err:
427	ceph_mdsmap_destroy(m);
428	return ERR_PTR(err);
429bad:
430	err = -EINVAL;
431	goto corrupt;
432}
433
434void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
435{
436	int i;
437
438	if (m->m_info) {
439		for (i = 0; i < m->possible_max_rank; i++)
440			kfree(m->m_info[i].export_targets);
441		kfree(m->m_info);
442	}
443	kfree(m->m_data_pg_pools);
444	kfree(m->m_fs_name);
445	kfree(m);
446}
447
448bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
449{
450	int i, nr_active = 0;
451	if (!m->m_enabled)
452		return false;
453	if (m->m_damaged)
454		return false;
455	if (m->m_num_laggy == m->m_num_active_mds)
456		return false;
457	for (i = 0; i < m->possible_max_rank; i++) {
458		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
459			nr_active++;
460	}
461	return nr_active > 0;
462}