xref: /openbmc/qemu/block/rbd.c (revision f1020c2c)
1 /*
2  * QEMU Block driver for RADOS (Ceph)
3  *
4  * Copyright (C) 2010-2011 Christian Brunner <chb@muc.de>,
5  *                         Josh Durgin <josh.durgin@dreamhost.com>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2.  See
8  * the COPYING file in the top-level directory.
9  *
10  * Contributions after 2012-01-13 are licensed under the terms of the
11  * GNU GPL, version 2 or (at your option) any later version.
12  */
13 
14 #include "qemu/osdep.h"
15 
16 #include "qapi/error.h"
17 #include "qemu/error-report.h"
18 #include "block/block_int.h"
19 #include "crypto/secret.h"
20 #include "qemu/cutils.h"
21 
22 #include <rbd/librbd.h>
23 
24 /*
25  * When specifying the image filename use:
26  *
27  * rbd:poolname/devicename[@snapshotname][:option1=value1[:option2=value2...]]
28  *
29  * poolname must be the name of an existing rados pool.
30  *
31  * devicename is the name of the rbd image.
32  *
33  * Each option given is used to configure rados, and may be any valid
34  * Ceph option, "id", or "conf".
35  *
36  * The "id" option indicates what user we should authenticate as to
37  * the Ceph cluster.  If it is excluded we will use the Ceph default
38  * (normally 'admin').
39  *
40  * The "conf" option specifies a Ceph configuration file to read.  If
41  * it is not specified, we will read from the default Ceph locations
42  * (e.g., /etc/ceph/ceph.conf).  To avoid reading _any_ configuration
43  * file, specify conf=/dev/null.
44  *
45  * Configuration values containing :, @, or = can be escaped with a
46  * leading "\".
47  */
48 
49 /* rbd_aio_discard added in 0.1.2 */
50 #if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 2)
51 #define LIBRBD_SUPPORTS_DISCARD
52 #else
53 #undef LIBRBD_SUPPORTS_DISCARD
54 #endif
55 
56 #define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER)
57 
58 #define RBD_MAX_CONF_NAME_SIZE 128
59 #define RBD_MAX_CONF_VAL_SIZE 512
60 #define RBD_MAX_CONF_SIZE 1024
61 #define RBD_MAX_POOL_NAME_SIZE 128
62 #define RBD_MAX_SNAP_NAME_SIZE 128
63 #define RBD_MAX_SNAPS 100
64 
65 typedef enum {
66     RBD_AIO_READ,
67     RBD_AIO_WRITE,
68     RBD_AIO_DISCARD,
69     RBD_AIO_FLUSH
70 } RBDAIOCmd;
71 
72 typedef struct RBDAIOCB {
73     BlockAIOCB common;
74     QEMUBH *bh;
75     int64_t ret;
76     QEMUIOVector *qiov;
77     char *bounce;
78     RBDAIOCmd cmd;
79     int error;
80     struct BDRVRBDState *s;
81 } RBDAIOCB;
82 
83 typedef struct RADOSCB {
84     RBDAIOCB *acb;
85     struct BDRVRBDState *s;
86     int64_t size;
87     char *buf;
88     int64_t ret;
89 } RADOSCB;
90 
91 typedef struct BDRVRBDState {
92     rados_t cluster;
93     rados_ioctx_t io_ctx;
94     rbd_image_t image;
95     char name[RBD_MAX_IMAGE_NAME_SIZE];
96     char *snap;
97 } BDRVRBDState;
98 
99 static int qemu_rbd_next_tok(char *dst, int dst_len,
100                              char *src, char delim,
101                              const char *name,
102                              char **p, Error **errp)
103 {
104     int l;
105     char *end;
106 
107     *p = NULL;
108 
109     if (delim != '\0') {
110         for (end = src; *end; ++end) {
111             if (*end == delim) {
112                 break;
113             }
114             if (*end == '\\' && end[1] != '\0') {
115                 end++;
116             }
117         }
118         if (*end == delim) {
119             *p = end + 1;
120             *end = '\0';
121         }
122     }
123     l = strlen(src);
124     if (l >= dst_len) {
125         error_setg(errp, "%s too long", name);
126         return -EINVAL;
127     } else if (l == 0) {
128         error_setg(errp, "%s too short", name);
129         return -EINVAL;
130     }
131 
132     pstrcpy(dst, dst_len, src);
133 
134     return 0;
135 }
136 
137 static void qemu_rbd_unescape(char *src)
138 {
139     char *p;
140 
141     for (p = src; *src; ++src, ++p) {
142         if (*src == '\\' && src[1] != '\0') {
143             src++;
144         }
145         *p = *src;
146     }
147     *p = '\0';
148 }
149 
150 static int qemu_rbd_parsename(const char *filename,
151                               char *pool, int pool_len,
152                               char *snap, int snap_len,
153                               char *name, int name_len,
154                               char *conf, int conf_len,
155                               Error **errp)
156 {
157     const char *start;
158     char *p, *buf;
159     int ret;
160 
161     if (!strstart(filename, "rbd:", &start)) {
162         error_setg(errp, "File name must start with 'rbd:'");
163         return -EINVAL;
164     }
165 
166     buf = g_strdup(start);
167     p = buf;
168     *snap = '\0';
169     *conf = '\0';
170 
171     ret = qemu_rbd_next_tok(pool, pool_len, p,
172                             '/', "pool name", &p, errp);
173     if (ret < 0 || !p) {
174         ret = -EINVAL;
175         goto done;
176     }
177     qemu_rbd_unescape(pool);
178 
179     if (strchr(p, '@')) {
180         ret = qemu_rbd_next_tok(name, name_len, p,
181                                 '@', "object name", &p, errp);
182         if (ret < 0) {
183             goto done;
184         }
185         ret = qemu_rbd_next_tok(snap, snap_len, p,
186                                 ':', "snap name", &p, errp);
187         qemu_rbd_unescape(snap);
188     } else {
189         ret = qemu_rbd_next_tok(name, name_len, p,
190                                 ':', "object name", &p, errp);
191     }
192     qemu_rbd_unescape(name);
193     if (ret < 0 || !p) {
194         goto done;
195     }
196 
197     ret = qemu_rbd_next_tok(conf, conf_len, p,
198                             '\0', "configuration", &p, errp);
199 
200 done:
201     g_free(buf);
202     return ret;
203 }
204 
205 static char *qemu_rbd_parse_clientname(const char *conf, char *clientname)
206 {
207     const char *p = conf;
208 
209     while (*p) {
210         int len;
211         const char *end = strchr(p, ':');
212 
213         if (end) {
214             len = end - p;
215         } else {
216             len = strlen(p);
217         }
218 
219         if (strncmp(p, "id=", 3) == 0) {
220             len -= 3;
221             strncpy(clientname, p + 3, len);
222             clientname[len] = '\0';
223             return clientname;
224         }
225         if (end == NULL) {
226             break;
227         }
228         p = end + 1;
229     }
230     return NULL;
231 }
232 
233 
234 static int qemu_rbd_set_auth(rados_t cluster, const char *secretid,
235                              Error **errp)
236 {
237     if (secretid == 0) {
238         return 0;
239     }
240 
241     gchar *secret = qcrypto_secret_lookup_as_base64(secretid,
242                                                     errp);
243     if (!secret) {
244         return -1;
245     }
246 
247     rados_conf_set(cluster, "key", secret);
248     g_free(secret);
249 
250     return 0;
251 }
252 
253 
254 static int qemu_rbd_set_conf(rados_t cluster, const char *conf,
255                              bool only_read_conf_file,
256                              Error **errp)
257 {
258     char *p, *buf;
259     char name[RBD_MAX_CONF_NAME_SIZE];
260     char value[RBD_MAX_CONF_VAL_SIZE];
261     int ret = 0;
262 
263     buf = g_strdup(conf);
264     p = buf;
265 
266     while (p) {
267         ret = qemu_rbd_next_tok(name, sizeof(name), p,
268                                 '=', "conf option name", &p, errp);
269         if (ret < 0) {
270             break;
271         }
272         qemu_rbd_unescape(name);
273 
274         if (!p) {
275             error_setg(errp, "conf option %s has no value", name);
276             ret = -EINVAL;
277             break;
278         }
279 
280         ret = qemu_rbd_next_tok(value, sizeof(value), p,
281                                 ':', "conf option value", &p, errp);
282         if (ret < 0) {
283             break;
284         }
285         qemu_rbd_unescape(value);
286 
287         if (strcmp(name, "conf") == 0) {
288             /* read the conf file alone, so it doesn't override more
289                specific settings for a particular device */
290             if (only_read_conf_file) {
291                 ret = rados_conf_read_file(cluster, value);
292                 if (ret < 0) {
293                     error_setg_errno(errp, -ret, "error reading conf file %s",
294                                      value);
295                     break;
296                 }
297             }
298         } else if (strcmp(name, "id") == 0) {
299             /* ignore, this is parsed by qemu_rbd_parse_clientname() */
300         } else if (!only_read_conf_file) {
301             ret = rados_conf_set(cluster, name, value);
302             if (ret < 0) {
303                 error_setg_errno(errp, -ret, "invalid conf option %s", name);
304                 ret = -EINVAL;
305                 break;
306             }
307         }
308     }
309 
310     g_free(buf);
311     return ret;
312 }
313 
314 static int qemu_rbd_create(const char *filename, QemuOpts *opts, Error **errp)
315 {
316     Error *local_err = NULL;
317     int64_t bytes = 0;
318     int64_t objsize;
319     int obj_order = 0;
320     char pool[RBD_MAX_POOL_NAME_SIZE];
321     char name[RBD_MAX_IMAGE_NAME_SIZE];
322     char snap_buf[RBD_MAX_SNAP_NAME_SIZE];
323     char conf[RBD_MAX_CONF_SIZE];
324     char clientname_buf[RBD_MAX_CONF_SIZE];
325     char *clientname;
326     const char *secretid;
327     rados_t cluster;
328     rados_ioctx_t io_ctx;
329     int ret;
330 
331     secretid = qemu_opt_get(opts, "password-secret");
332 
333     if (qemu_rbd_parsename(filename, pool, sizeof(pool),
334                            snap_buf, sizeof(snap_buf),
335                            name, sizeof(name),
336                            conf, sizeof(conf), &local_err) < 0) {
337         error_propagate(errp, local_err);
338         return -EINVAL;
339     }
340 
341     /* Read out options */
342     bytes = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
343                      BDRV_SECTOR_SIZE);
344     objsize = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 0);
345     if (objsize) {
346         if ((objsize - 1) & objsize) {    /* not a power of 2? */
347             error_setg(errp, "obj size needs to be power of 2");
348             return -EINVAL;
349         }
350         if (objsize < 4096) {
351             error_setg(errp, "obj size too small");
352             return -EINVAL;
353         }
354         obj_order = ctz32(objsize);
355     }
356 
357     clientname = qemu_rbd_parse_clientname(conf, clientname_buf);
358     ret = rados_create(&cluster, clientname);
359     if (ret < 0) {
360         error_setg_errno(errp, -ret, "error initializing");
361         return ret;
362     }
363 
364     if (strstr(conf, "conf=") == NULL) {
365         /* try default location, but ignore failure */
366         rados_conf_read_file(cluster, NULL);
367     } else if (conf[0] != '\0' &&
368                qemu_rbd_set_conf(cluster, conf, true, &local_err) < 0) {
369         rados_shutdown(cluster);
370         error_propagate(errp, local_err);
371         return -EIO;
372     }
373 
374     if (conf[0] != '\0' &&
375         qemu_rbd_set_conf(cluster, conf, false, &local_err) < 0) {
376         rados_shutdown(cluster);
377         error_propagate(errp, local_err);
378         return -EIO;
379     }
380 
381     if (qemu_rbd_set_auth(cluster, secretid, errp) < 0) {
382         rados_shutdown(cluster);
383         return -EIO;
384     }
385 
386     ret = rados_connect(cluster);
387     if (ret < 0) {
388         error_setg_errno(errp, -ret, "error connecting");
389         rados_shutdown(cluster);
390         return ret;
391     }
392 
393     ret = rados_ioctx_create(cluster, pool, &io_ctx);
394     if (ret < 0) {
395         error_setg_errno(errp, -ret, "error opening pool %s", pool);
396         rados_shutdown(cluster);
397         return ret;
398     }
399 
400     ret = rbd_create(io_ctx, name, bytes, &obj_order);
401     rados_ioctx_destroy(io_ctx);
402     rados_shutdown(cluster);
403     if (ret < 0) {
404         error_setg_errno(errp, -ret, "error rbd create");
405         return ret;
406     }
407 
408     return ret;
409 }
410 
411 /*
412  * This aio completion is being called from rbd_finish_bh() and runs in qemu
413  * BH context.
414  */
415 static void qemu_rbd_complete_aio(RADOSCB *rcb)
416 {
417     RBDAIOCB *acb = rcb->acb;
418     int64_t r;
419 
420     r = rcb->ret;
421 
422     if (acb->cmd != RBD_AIO_READ) {
423         if (r < 0) {
424             acb->ret = r;
425             acb->error = 1;
426         } else if (!acb->error) {
427             acb->ret = rcb->size;
428         }
429     } else {
430         if (r < 0) {
431             memset(rcb->buf, 0, rcb->size);
432             acb->ret = r;
433             acb->error = 1;
434         } else if (r < rcb->size) {
435             memset(rcb->buf + r, 0, rcb->size - r);
436             if (!acb->error) {
437                 acb->ret = rcb->size;
438             }
439         } else if (!acb->error) {
440             acb->ret = r;
441         }
442     }
443 
444     g_free(rcb);
445 
446     if (acb->cmd == RBD_AIO_READ) {
447         qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
448     }
449     qemu_vfree(acb->bounce);
450     acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
451 
452     qemu_aio_unref(acb);
453 }
454 
455 /* TODO Convert to fine grained options */
456 static QemuOptsList runtime_opts = {
457     .name = "rbd",
458     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
459     .desc = {
460         {
461             .name = "filename",
462             .type = QEMU_OPT_STRING,
463             .help = "Specification of the rbd image",
464         },
465         {
466             .name = "password-secret",
467             .type = QEMU_OPT_STRING,
468             .help = "ID of secret providing the password",
469         },
470         { /* end of list */ }
471     },
472 };
473 
474 static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
475                          Error **errp)
476 {
477     BDRVRBDState *s = bs->opaque;
478     char pool[RBD_MAX_POOL_NAME_SIZE];
479     char snap_buf[RBD_MAX_SNAP_NAME_SIZE];
480     char conf[RBD_MAX_CONF_SIZE];
481     char clientname_buf[RBD_MAX_CONF_SIZE];
482     char *clientname;
483     const char *secretid;
484     QemuOpts *opts;
485     Error *local_err = NULL;
486     const char *filename;
487     int r;
488 
489     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
490     qemu_opts_absorb_qdict(opts, options, &local_err);
491     if (local_err) {
492         error_propagate(errp, local_err);
493         qemu_opts_del(opts);
494         return -EINVAL;
495     }
496 
497     filename = qemu_opt_get(opts, "filename");
498     secretid = qemu_opt_get(opts, "password-secret");
499 
500     if (qemu_rbd_parsename(filename, pool, sizeof(pool),
501                            snap_buf, sizeof(snap_buf),
502                            s->name, sizeof(s->name),
503                            conf, sizeof(conf), errp) < 0) {
504         r = -EINVAL;
505         goto failed_opts;
506     }
507 
508     clientname = qemu_rbd_parse_clientname(conf, clientname_buf);
509     r = rados_create(&s->cluster, clientname);
510     if (r < 0) {
511         error_setg_errno(errp, -r, "error initializing");
512         goto failed_opts;
513     }
514 
515     s->snap = NULL;
516     if (snap_buf[0] != '\0') {
517         s->snap = g_strdup(snap_buf);
518     }
519 
520     if (strstr(conf, "conf=") == NULL) {
521         /* try default location, but ignore failure */
522         rados_conf_read_file(s->cluster, NULL);
523     } else if (conf[0] != '\0') {
524         r = qemu_rbd_set_conf(s->cluster, conf, true, errp);
525         if (r < 0) {
526             goto failed_shutdown;
527         }
528     }
529 
530     if (conf[0] != '\0') {
531         r = qemu_rbd_set_conf(s->cluster, conf, false, errp);
532         if (r < 0) {
533             goto failed_shutdown;
534         }
535     }
536 
537     if (qemu_rbd_set_auth(s->cluster, secretid, errp) < 0) {
538         r = -EIO;
539         goto failed_shutdown;
540     }
541 
542     /*
543      * Fallback to more conservative semantics if setting cache
544      * options fails. Ignore errors from setting rbd_cache because the
545      * only possible error is that the option does not exist, and
546      * librbd defaults to no caching. If write through caching cannot
547      * be set up, fall back to no caching.
548      */
549     if (flags & BDRV_O_NOCACHE) {
550         rados_conf_set(s->cluster, "rbd_cache", "false");
551     } else {
552         rados_conf_set(s->cluster, "rbd_cache", "true");
553     }
554 
555     r = rados_connect(s->cluster);
556     if (r < 0) {
557         error_setg_errno(errp, -r, "error connecting");
558         goto failed_shutdown;
559     }
560 
561     r = rados_ioctx_create(s->cluster, pool, &s->io_ctx);
562     if (r < 0) {
563         error_setg_errno(errp, -r, "error opening pool %s", pool);
564         goto failed_shutdown;
565     }
566 
567     r = rbd_open(s->io_ctx, s->name, &s->image, s->snap);
568     if (r < 0) {
569         error_setg_errno(errp, -r, "error reading header from %s", s->name);
570         goto failed_open;
571     }
572 
573     bs->read_only = (s->snap != NULL);
574 
575     qemu_opts_del(opts);
576     return 0;
577 
578 failed_open:
579     rados_ioctx_destroy(s->io_ctx);
580 failed_shutdown:
581     rados_shutdown(s->cluster);
582     g_free(s->snap);
583 failed_opts:
584     qemu_opts_del(opts);
585     return r;
586 }
587 
588 static void qemu_rbd_close(BlockDriverState *bs)
589 {
590     BDRVRBDState *s = bs->opaque;
591 
592     rbd_close(s->image);
593     rados_ioctx_destroy(s->io_ctx);
594     g_free(s->snap);
595     rados_shutdown(s->cluster);
596 }
597 
598 static const AIOCBInfo rbd_aiocb_info = {
599     .aiocb_size = sizeof(RBDAIOCB),
600 };
601 
602 static void rbd_finish_bh(void *opaque)
603 {
604     RADOSCB *rcb = opaque;
605     qemu_bh_delete(rcb->acb->bh);
606     qemu_rbd_complete_aio(rcb);
607 }
608 
609 /*
610  * This is the callback function for rbd_aio_read and _write
611  *
612  * Note: this function is being called from a non qemu thread so
613  * we need to be careful about what we do here. Generally we only
614  * schedule a BH, and do the rest of the io completion handling
615  * from rbd_finish_bh() which runs in a qemu context.
616  */
617 static void rbd_finish_aiocb(rbd_completion_t c, RADOSCB *rcb)
618 {
619     RBDAIOCB *acb = rcb->acb;
620 
621     rcb->ret = rbd_aio_get_return_value(c);
622     rbd_aio_release(c);
623 
624     acb->bh = aio_bh_new(bdrv_get_aio_context(acb->common.bs),
625                          rbd_finish_bh, rcb);
626     qemu_bh_schedule(acb->bh);
627 }
628 
629 static int rbd_aio_discard_wrapper(rbd_image_t image,
630                                    uint64_t off,
631                                    uint64_t len,
632                                    rbd_completion_t comp)
633 {
634 #ifdef LIBRBD_SUPPORTS_DISCARD
635     return rbd_aio_discard(image, off, len, comp);
636 #else
637     return -ENOTSUP;
638 #endif
639 }
640 
641 static int rbd_aio_flush_wrapper(rbd_image_t image,
642                                  rbd_completion_t comp)
643 {
644 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH
645     return rbd_aio_flush(image, comp);
646 #else
647     return -ENOTSUP;
648 #endif
649 }
650 
651 static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
652                                  int64_t sector_num,
653                                  QEMUIOVector *qiov,
654                                  int nb_sectors,
655                                  BlockCompletionFunc *cb,
656                                  void *opaque,
657                                  RBDAIOCmd cmd)
658 {
659     RBDAIOCB *acb;
660     RADOSCB *rcb = NULL;
661     rbd_completion_t c;
662     int64_t off, size;
663     char *buf;
664     int r;
665 
666     BDRVRBDState *s = bs->opaque;
667 
668     acb = qemu_aio_get(&rbd_aiocb_info, bs, cb, opaque);
669     acb->cmd = cmd;
670     acb->qiov = qiov;
671     if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
672         acb->bounce = NULL;
673     } else {
674         acb->bounce = qemu_try_blockalign(bs, qiov->size);
675         if (acb->bounce == NULL) {
676             goto failed;
677         }
678     }
679     acb->ret = 0;
680     acb->error = 0;
681     acb->s = s;
682     acb->bh = NULL;
683 
684     if (cmd == RBD_AIO_WRITE) {
685         qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
686     }
687 
688     buf = acb->bounce;
689 
690     off = sector_num * BDRV_SECTOR_SIZE;
691     size = nb_sectors * BDRV_SECTOR_SIZE;
692 
693     rcb = g_new(RADOSCB, 1);
694     rcb->acb = acb;
695     rcb->buf = buf;
696     rcb->s = acb->s;
697     rcb->size = size;
698     r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, &c);
699     if (r < 0) {
700         goto failed;
701     }
702 
703     switch (cmd) {
704     case RBD_AIO_WRITE:
705         r = rbd_aio_write(s->image, off, size, buf, c);
706         break;
707     case RBD_AIO_READ:
708         r = rbd_aio_read(s->image, off, size, buf, c);
709         break;
710     case RBD_AIO_DISCARD:
711         r = rbd_aio_discard_wrapper(s->image, off, size, c);
712         break;
713     case RBD_AIO_FLUSH:
714         r = rbd_aio_flush_wrapper(s->image, c);
715         break;
716     default:
717         r = -EINVAL;
718     }
719 
720     if (r < 0) {
721         goto failed_completion;
722     }
723 
724     return &acb->common;
725 
726 failed_completion:
727     rbd_aio_release(c);
728 failed:
729     g_free(rcb);
730     qemu_vfree(acb->bounce);
731     qemu_aio_unref(acb);
732     return NULL;
733 }
734 
735 static BlockAIOCB *qemu_rbd_aio_readv(BlockDriverState *bs,
736                                       int64_t sector_num,
737                                       QEMUIOVector *qiov,
738                                       int nb_sectors,
739                                       BlockCompletionFunc *cb,
740                                       void *opaque)
741 {
742     return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque,
743                          RBD_AIO_READ);
744 }
745 
746 static BlockAIOCB *qemu_rbd_aio_writev(BlockDriverState *bs,
747                                        int64_t sector_num,
748                                        QEMUIOVector *qiov,
749                                        int nb_sectors,
750                                        BlockCompletionFunc *cb,
751                                        void *opaque)
752 {
753     return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque,
754                          RBD_AIO_WRITE);
755 }
756 
757 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH
758 static BlockAIOCB *qemu_rbd_aio_flush(BlockDriverState *bs,
759                                       BlockCompletionFunc *cb,
760                                       void *opaque)
761 {
762     return rbd_start_aio(bs, 0, NULL, 0, cb, opaque, RBD_AIO_FLUSH);
763 }
764 
765 #else
766 
767 static int qemu_rbd_co_flush(BlockDriverState *bs)
768 {
769 #if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 1)
770     /* rbd_flush added in 0.1.1 */
771     BDRVRBDState *s = bs->opaque;
772     return rbd_flush(s->image);
773 #else
774     return 0;
775 #endif
776 }
777 #endif
778 
779 static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi)
780 {
781     BDRVRBDState *s = bs->opaque;
782     rbd_image_info_t info;
783     int r;
784 
785     r = rbd_stat(s->image, &info, sizeof(info));
786     if (r < 0) {
787         return r;
788     }
789 
790     bdi->cluster_size = info.obj_size;
791     return 0;
792 }
793 
794 static int64_t qemu_rbd_getlength(BlockDriverState *bs)
795 {
796     BDRVRBDState *s = bs->opaque;
797     rbd_image_info_t info;
798     int r;
799 
800     r = rbd_stat(s->image, &info, sizeof(info));
801     if (r < 0) {
802         return r;
803     }
804 
805     return info.size;
806 }
807 
808 static int qemu_rbd_truncate(BlockDriverState *bs, int64_t offset)
809 {
810     BDRVRBDState *s = bs->opaque;
811     int r;
812 
813     r = rbd_resize(s->image, offset);
814     if (r < 0) {
815         return r;
816     }
817 
818     return 0;
819 }
820 
821 static int qemu_rbd_snap_create(BlockDriverState *bs,
822                                 QEMUSnapshotInfo *sn_info)
823 {
824     BDRVRBDState *s = bs->opaque;
825     int r;
826 
827     if (sn_info->name[0] == '\0') {
828         return -EINVAL; /* we need a name for rbd snapshots */
829     }
830 
831     /*
832      * rbd snapshots are using the name as the user controlled unique identifier
833      * we can't use the rbd snapid for that purpose, as it can't be set
834      */
835     if (sn_info->id_str[0] != '\0' &&
836         strcmp(sn_info->id_str, sn_info->name) != 0) {
837         return -EINVAL;
838     }
839 
840     if (strlen(sn_info->name) >= sizeof(sn_info->id_str)) {
841         return -ERANGE;
842     }
843 
844     r = rbd_snap_create(s->image, sn_info->name);
845     if (r < 0) {
846         error_report("failed to create snap: %s", strerror(-r));
847         return r;
848     }
849 
850     return 0;
851 }
852 
853 static int qemu_rbd_snap_remove(BlockDriverState *bs,
854                                 const char *snapshot_id,
855                                 const char *snapshot_name,
856                                 Error **errp)
857 {
858     BDRVRBDState *s = bs->opaque;
859     int r;
860 
861     if (!snapshot_name) {
862         error_setg(errp, "rbd need a valid snapshot name");
863         return -EINVAL;
864     }
865 
866     /* If snapshot_id is specified, it must be equal to name, see
867        qemu_rbd_snap_list() */
868     if (snapshot_id && strcmp(snapshot_id, snapshot_name)) {
869         error_setg(errp,
870                    "rbd do not support snapshot id, it should be NULL or "
871                    "equal to snapshot name");
872         return -EINVAL;
873     }
874 
875     r = rbd_snap_remove(s->image, snapshot_name);
876     if (r < 0) {
877         error_setg_errno(errp, -r, "Failed to remove the snapshot");
878     }
879     return r;
880 }
881 
882 static int qemu_rbd_snap_rollback(BlockDriverState *bs,
883                                   const char *snapshot_name)
884 {
885     BDRVRBDState *s = bs->opaque;
886     int r;
887 
888     r = rbd_snap_rollback(s->image, snapshot_name);
889     return r;
890 }
891 
892 static int qemu_rbd_snap_list(BlockDriverState *bs,
893                               QEMUSnapshotInfo **psn_tab)
894 {
895     BDRVRBDState *s = bs->opaque;
896     QEMUSnapshotInfo *sn_info, *sn_tab = NULL;
897     int i, snap_count;
898     rbd_snap_info_t *snaps;
899     int max_snaps = RBD_MAX_SNAPS;
900 
901     do {
902         snaps = g_new(rbd_snap_info_t, max_snaps);
903         snap_count = rbd_snap_list(s->image, snaps, &max_snaps);
904         if (snap_count <= 0) {
905             g_free(snaps);
906         }
907     } while (snap_count == -ERANGE);
908 
909     if (snap_count <= 0) {
910         goto done;
911     }
912 
913     sn_tab = g_new0(QEMUSnapshotInfo, snap_count);
914 
915     for (i = 0; i < snap_count; i++) {
916         const char *snap_name = snaps[i].name;
917 
918         sn_info = sn_tab + i;
919         pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), snap_name);
920         pstrcpy(sn_info->name, sizeof(sn_info->name), snap_name);
921 
922         sn_info->vm_state_size = snaps[i].size;
923         sn_info->date_sec = 0;
924         sn_info->date_nsec = 0;
925         sn_info->vm_clock_nsec = 0;
926     }
927     rbd_snap_list_end(snaps);
928     g_free(snaps);
929 
930  done:
931     *psn_tab = sn_tab;
932     return snap_count;
933 }
934 
935 #ifdef LIBRBD_SUPPORTS_DISCARD
936 static BlockAIOCB* qemu_rbd_aio_discard(BlockDriverState *bs,
937                                         int64_t sector_num,
938                                         int nb_sectors,
939                                         BlockCompletionFunc *cb,
940                                         void *opaque)
941 {
942     return rbd_start_aio(bs, sector_num, NULL, nb_sectors, cb, opaque,
943                          RBD_AIO_DISCARD);
944 }
945 #endif
946 
947 #ifdef LIBRBD_SUPPORTS_INVALIDATE
948 static void qemu_rbd_invalidate_cache(BlockDriverState *bs,
949                                       Error **errp)
950 {
951     BDRVRBDState *s = bs->opaque;
952     int r = rbd_invalidate_cache(s->image);
953     if (r < 0) {
954         error_setg_errno(errp, -r, "Failed to invalidate the cache");
955     }
956 }
957 #endif
958 
959 static QemuOptsList qemu_rbd_create_opts = {
960     .name = "rbd-create-opts",
961     .head = QTAILQ_HEAD_INITIALIZER(qemu_rbd_create_opts.head),
962     .desc = {
963         {
964             .name = BLOCK_OPT_SIZE,
965             .type = QEMU_OPT_SIZE,
966             .help = "Virtual disk size"
967         },
968         {
969             .name = BLOCK_OPT_CLUSTER_SIZE,
970             .type = QEMU_OPT_SIZE,
971             .help = "RBD object size"
972         },
973         {
974             .name = "password-secret",
975             .type = QEMU_OPT_STRING,
976             .help = "ID of secret providing the password",
977         },
978         { /* end of list */ }
979     }
980 };
981 
982 static BlockDriver bdrv_rbd = {
983     .format_name        = "rbd",
984     .instance_size      = sizeof(BDRVRBDState),
985     .bdrv_needs_filename = true,
986     .bdrv_file_open     = qemu_rbd_open,
987     .bdrv_close         = qemu_rbd_close,
988     .bdrv_create        = qemu_rbd_create,
989     .bdrv_has_zero_init = bdrv_has_zero_init_1,
990     .bdrv_get_info      = qemu_rbd_getinfo,
991     .create_opts        = &qemu_rbd_create_opts,
992     .bdrv_getlength     = qemu_rbd_getlength,
993     .bdrv_truncate      = qemu_rbd_truncate,
994     .protocol_name      = "rbd",
995 
996     .bdrv_aio_readv         = qemu_rbd_aio_readv,
997     .bdrv_aio_writev        = qemu_rbd_aio_writev,
998 
999 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH
1000     .bdrv_aio_flush         = qemu_rbd_aio_flush,
1001 #else
1002     .bdrv_co_flush_to_disk  = qemu_rbd_co_flush,
1003 #endif
1004 
1005 #ifdef LIBRBD_SUPPORTS_DISCARD
1006     .bdrv_aio_discard       = qemu_rbd_aio_discard,
1007 #endif
1008 
1009     .bdrv_snapshot_create   = qemu_rbd_snap_create,
1010     .bdrv_snapshot_delete   = qemu_rbd_snap_remove,
1011     .bdrv_snapshot_list     = qemu_rbd_snap_list,
1012     .bdrv_snapshot_goto     = qemu_rbd_snap_rollback,
1013 #ifdef LIBRBD_SUPPORTS_INVALIDATE
1014     .bdrv_invalidate_cache  = qemu_rbd_invalidate_cache,
1015 #endif
1016 };
1017 
1018 static void bdrv_rbd_init(void)
1019 {
1020     bdrv_register(&bdrv_rbd);
1021 }
1022 
1023 block_init(bdrv_rbd_init);
1024