| 1 | |
| 2 | #include <linux/ceph/ceph_debug.h>
|
| 3 |
|
| 4 | #include <linux/fs.h>
|
| 5 | #include <linux/sort.h>
|
| 6 | #include <linux/slab.h>
|
| 7 | #include <linux/iversion.h>
|
| 8 | #include "super.h"
|
| 9 | #include "mds_client.h"
|
| 10 | #include <linux/ceph/decode.h>
|
| 11 |
|
| 12 |
|
| 13 | #define CEPH_SNAPID_MAP_TIMEOUT (5 * 60 * HZ)
|
| 14 |
|
| 15 | |
| 16 | * Snapshots in ceph are driven in large part by cooperation from the
|
| 17 | * client. In contrast to local file systems or file servers that
|
| 18 | * implement snapshots at a single point in the system, ceph's
|
| 19 | * distributed access to storage requires clients to help decide
|
| 20 | * whether a write logically occurs before or after a recently created
|
| 21 | * snapshot.
|
| 22 | *
|
| 23 | * This provides a perfect instantanous client-wide snapshot. Between
|
| 24 | * clients, however, snapshots may appear to be applied at slightly
|
| 25 | * different points in time, depending on delays in delivering the
|
| 26 | * snapshot notification.
|
| 27 | *
|
| 28 | * Snapshots are _not_ file system-wide. Instead, each snapshot
|
| 29 | * applies to the subdirectory nested beneath some directory. This
|
| 30 | * effectively divides the hierarchy into multiple "realms," where all
|
| 31 | * of the files contained by each realm share the same set of
|
| 32 | * snapshots. An individual realm's snap set contains snapshots
|
| 33 | * explicitly created on that realm, as well as any snaps in its
|
| 34 | * parent's snap set _after_ the point at which the parent became it's
|
| 35 | * parent (due to, say, a rename). Similarly, snaps from prior parents
|
| 36 | * during the time intervals during which they were the parent are included.
|
| 37 | *
|
| 38 | * The client is spared most of this detail, fortunately... it must only
|
| 39 | * maintains a hierarchy of realms reflecting the current parent/child
|
| 40 | * realm relationship, and for each realm has an explicit list of snaps
|
| 41 | * inherited from prior parents.
|
| 42 | *
|
| 43 | * A snap_realm struct is maintained for realms containing every inode
|
| 44 | * with an open cap in the system. (The needed snap realm information is
|
| 45 | * provided by the MDS whenever a cap is issued, i.e., on open.) A 'seq'
|
| 46 | * version number is used to ensure that as realm parameters change (new
|
| 47 | * snapshot, new parent, etc.) the client's realm hierarchy is updated.
|
| 48 | *
|
| 49 | * The realm hierarchy drives the generation of a 'snap context' for each
|
| 50 | * realm, which simply lists the resulting set of snaps for the realm. This
|
| 51 | * is attached to any writes sent to OSDs.
|
| 52 |
|
| 53 | |
| 54 | * Unfortunately error handling is a bit mixed here. If we get a snap
|
| 55 | * update, but don't have enough memory to update our realm hierarchy,
|
| 56 | * it's not clear what we can do about it (besides complaining to the
|
| 57 | * console).
|
| 58 |
|
| 59 |
|
| 60 |
|
| 61 | |
| 62 | * increase ref count for the realm
|
| 63 | *
|
| 64 | * caller must hold snap_rwsem.
|
| 65 |
|
| 66 | void ceph_get_snap_realm(struct ceph_mds_client *mdsc,
|
| 67 | struct ceph_snap_realm *realm)
|
| 68 | {
|
| 69 | lockdep_assert_held(&mdsc->snap_rwsem);
|
| 70 |
|
| 71 | |
| 72 | * The 0->1 and 1->0 transitions must take the snap_empty_lock
|
| 73 | * atomically with the refcount change. Go ahead and bump the
|
| 74 | * nref here, unless it's 0, in which case we take the spinlock
|
| 75 | * and then do the increment and remove it from the list.
|
| 76 |
|
| 77 | if (atomic_inc_not_zero(&realm->nref))
|
| 78 | return;
|
| 79 |
|
| 80 | spin_lock(&mdsc->snap_empty_lock);
|
| 81 | if (atomic_inc_return(&realm->nref) == 1)
|
| 82 | list_del_init(&realm->empty_item);
|
| 83 | spin_unlock(&mdsc->snap_empty_lock);
|
| 84 | }
|
| 85 |
|
| 86 | static void __insert_snap_realm(struct rb_root *root,
|
| 87 | struct ceph_snap_realm *new)
|
| 88 | {
|
| 89 | struct rb_node **p = &root->rb_node;
|
| 90 | struct rb_node *parent = NULL;
|
| 91 | struct ceph_snap_realm *r = NULL;
|
| 92 |
|
| 93 | while (*p) {
|
| 94 | parent = *p;
|
| 95 | r = rb_entry(parent, struct ceph_snap_realm, node);
|
| 96 | if (new->ino < r->ino)
|
| 97 | p = &(*p)->rb_left;
|
| 98 | else if (new->ino > r->ino)
|
| 99 | p = &(*p)->rb_right;
|
| 100 | else
|
| 101 | BUG();
|
| 102 | }
|
| 103 |
|
| 104 | rb_link_node(&new->node, parent, p);
|
| 105 | rb_insert_color(&new->node, root);
|
| 106 | }
|
| 107 |
|
| 108 | |
| 109 | * create and get the realm rooted at @ino and bump its ref count.
|
| 110 | *
|
| 111 | * caller must hold snap_rwsem for write.
|
| 112 |
|
| 113 | static struct ceph_snap_realm *ceph_create_snap_realm(
|
| 114 | struct ceph_mds_client *mdsc,
|
| 115 | u64 ino)
|
| 116 | {
|
| 117 | struct ceph_snap_realm *realm;
|
| 118 |
|
| 119 | lockdep_assert_held_write(&mdsc->snap_rwsem);
|
| 120 |
|
| 121 | realm = kzalloc_obj(*realm, GFP_NOFS);
|
| 122 | if (!realm)
|
| 123 | return ERR_PTR(-ENOMEM);
|
| 124 |
|
| 125 |
|
| 126 | if (ino == CEPH_INO_GLOBAL_SNAPREALM)
|
| 127 | atomic_set(&realm->nref, 2);
|
| 128 | else
|
| 129 | atomic_set(&realm->nref, 1);
|
| 130 | realm->ino = ino;
|
| 131 | INIT_LIST_HEAD(&realm->children);
|
| 132 | INIT_LIST_HEAD(&realm->child_item);
|
| 133 | INIT_LIST_HEAD(&realm->empty_item);
|
| 134 | INIT_LIST_HEAD(&realm->dirty_item);
|
| 135 | INIT_LIST_HEAD(&realm->rebuild_item);
|
| 136 | INIT_LIST_HEAD(&realm->inodes_with_caps);
|
| 137 | spin_lock_init(&realm->inodes_with_caps_lock);
|
| 138 | __insert_snap_realm(&mdsc->snap_realms, realm);
|
| 139 | mdsc->num_snap_realms++;
|
| 140 |
|
| 141 | doutc(mdsc->fsc->client, "%llx %p\n", realm->ino, realm);
|
| 142 | return realm;
|
| 143 | }
|
| 144 |
|
| 145 | |
| 146 | * lookup the realm rooted at @ino.
|
| 147 | *
|
| 148 | * caller must hold snap_rwsem.
|
| 149 |
|
| 150 | static struct ceph_snap_realm *__lookup_snap_realm(struct ceph_mds_client *mdsc,
|
| 151 | u64 ino)
|
| 152 | {
|
| 153 | struct ceph_client *cl = mdsc->fsc->client;
|
| 154 | struct rb_node *n = mdsc->snap_realms.rb_node;
|
| 155 | struct ceph_snap_realm *r;
|
| 156 |
|
| 157 | lockdep_assert_held(&mdsc->snap_rwsem);
|
| 158 |
|
| 159 | while (n) {
|
| 160 | r = rb_entry(n, struct ceph_snap_realm, node);
|
| 161 | if (ino < r->ino)
|
| 162 | n = n->rb_left;
|
| 163 | else if (ino > r->ino)
|
| 164 | n = n->rb_right;
|
| 165 | else {
|
| 166 | doutc(cl, "%llx %p\n", r->ino, r);
|
| 167 | return r;
|
| 168 | }
|
| 169 | }
|
| 170 | return NULL;
|
| 171 | }
|
| 172 |
|
| 173 | struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
|
| 174 | u64 ino)
|
| 175 | {
|
| 176 | struct ceph_snap_realm *r;
|
| 177 | r = __lookup_snap_realm(mdsc, ino);
|
| 178 | if (r)
|
| 179 | ceph_get_snap_realm(mdsc, r);
|
| 180 | return r;
|
| 181 | }
|
| 182 |
|
| 183 | static void __put_snap_realm(struct ceph_mds_client *mdsc,
|
| 184 | struct ceph_snap_realm *realm);
|
| 185 |
|
| 186 | |
| 187 | * called with snap_rwsem (write)
|
| 188 |
|
| 189 | static void __destroy_snap_realm(struct ceph_mds_client *mdsc,
|
| 190 | struct ceph_snap_realm *realm)
|
| 191 | {
|
| 192 | struct ceph_client *cl = mdsc->fsc->client;
|
| 193 | lockdep_assert_held_write(&mdsc->snap_rwsem);
|
| 194 |
|
| 195 | doutc(cl, "%p %llx\n", realm, realm->ino);
|
| 196 |
|
| 197 | rb_erase(&realm->node, &mdsc->snap_realms);
|
| 198 | mdsc->num_snap_realms--;
|
| 199 |
|
| 200 | if (realm->parent) {
|
| 201 | list_del_init(&realm->child_item);
|
| 202 | __put_snap_realm(mdsc, realm->parent);
|
| 203 | }
|
| 204 |
|
| 205 | kfree(realm->prior_parent_snaps);
|
| 206 | kfree(realm->snaps);
|
| 207 | ceph_put_snap_context(realm->cached_context);
|
| 208 | kfree(realm);
|
| 209 | }
|
| 210 |
|
| 211 | |
| 212 | * caller holds snap_rwsem (write)
|
| 213 |
|
| 214 | static void __put_snap_realm(struct ceph_mds_client *mdsc,
|
| 215 | struct ceph_snap_realm *realm)
|
| 216 | {
|
| 217 | lockdep_assert_held_write(&mdsc->snap_rwsem);
|
| 218 |
|
| 219 | |
| 220 | * We do not require the snap_empty_lock here, as any caller that
|
| 221 | * increments the value must hold the snap_rwsem.
|
| 222 |
|
| 223 | if (atomic_dec_and_test(&realm->nref))
|
| 224 | __destroy_snap_realm(mdsc, realm);
|
| 225 | }
|
| 226 |
|
| 227 | |
| 228 | * See comments in ceph_get_snap_realm. Caller needn't hold any locks.
|
| 229 |
|
| 230 | void ceph_put_snap_realm(struct ceph_mds_client *mdsc,
|
| 231 | struct ceph_snap_realm *realm)
|
| 232 | {
|
| 233 | if (!atomic_dec_and_lock(&realm->nref, &mdsc->snap_empty_lock))
|
| 234 | return;
|
| 235 |
|
| 236 | if (down_write_trylock(&mdsc->snap_rwsem)) {
|
| 237 | spin_unlock(&mdsc->snap_empty_lock);
|
| 238 | __destroy_snap_realm(mdsc, realm);
|
| 239 | up_write(&mdsc->snap_rwsem);
|
| 240 | } else {
|
| 241 | list_add(&realm->empty_item, &mdsc->snap_empty);
|
| 242 | spin_unlock(&mdsc->snap_empty_lock);
|
| 243 | }
|
| 244 | }
|
| 245 |
|
| 246 | |
| 247 | * Clean up any realms whose ref counts have dropped to zero. Note
|
| 248 | * that this does not include realms who were created but not yet
|
| 249 | * used.
|
| 250 | *
|
| 251 | * Called under snap_rwsem (write)
|
| 252 |
|
| 253 | static void __cleanup_empty_realms(struct ceph_mds_client *mdsc)
|
| 254 | {
|
| 255 | struct ceph_snap_realm *realm;
|
| 256 |
|
| 257 | lockdep_assert_held_write(&mdsc->snap_rwsem);
|
| 258 |
|
| 259 | spin_lock(&mdsc->snap_empty_lock);
|
| 260 | while (!list_empty(&mdsc->snap_empty)) {
|
| 261 | realm = list_first_entry(&mdsc->snap_empty,
|
| 262 | struct ceph_snap_realm, empty_item);
|
| 263 | list_del(&realm->empty_item);
|
| 264 | spin_unlock(&mdsc->snap_empty_lock);
|
| 265 | __destroy_snap_realm(mdsc, realm);
|
| 266 | spin_lock(&mdsc->snap_empty_lock);
|
| 267 | }
|
| 268 | spin_unlock(&mdsc->snap_empty_lock);
|
| 269 | }
|
| 270 |
|
| 271 | void ceph_cleanup_global_and_empty_realms(struct ceph_mds_client *mdsc)
|
| 272 | {
|
| 273 | struct ceph_snap_realm *global_realm;
|
| 274 |
|
| 275 | down_write(&mdsc->snap_rwsem);
|
| 276 | global_realm = __lookup_snap_realm(mdsc, CEPH_INO_GLOBAL_SNAPREALM);
|
| 277 | if (global_realm)
|
| 278 | ceph_put_snap_realm(mdsc, global_realm);
|
| 279 | __cleanup_empty_realms(mdsc);
|
| 280 | up_write(&mdsc->snap_rwsem);
|
| 281 | }
|
| 282 |
|
| 283 | |
| 284 | * adjust the parent realm of a given @realm. adjust child list, and parent
|
| 285 | * pointers, and ref counts appropriately.
|
| 286 | *
|
| 287 | * return true if parent was changed, 0 if unchanged, <0 on error.
|
| 288 | *
|
| 289 | * caller must hold snap_rwsem for write.
|
| 290 |
|
| 291 | static int adjust_snap_realm_parent(struct ceph_mds_client *mdsc,
|
| 292 | struct ceph_snap_realm *realm,
|
| 293 | u64 parentino)
|
| 294 | {
|
| 295 | struct ceph_client *cl = mdsc->fsc->client;
|
| 296 | struct ceph_snap_realm *parent;
|
| 297 |
|
| 298 | lockdep_assert_held_write(&mdsc->snap_rwsem);
|
| 299 |
|
| 300 | if (realm->parent_ino == parentino)
|
| 301 | return 0;
|
| 302 |
|
| 303 | parent = ceph_lookup_snap_realm(mdsc, parentino);
|
| 304 | if (!parent) {
|
| 305 | parent = ceph_create_snap_realm(mdsc, parentino);
|
| 306 | if (IS_ERR(parent))
|
| 307 | return PTR_ERR(parent);
|
| 308 | }
|
| 309 | doutc(cl, "%llx %p: %llx %p -> %llx %p\n", realm->ino, realm,
|
| 310 | realm->parent_ino, realm->parent, parentino, parent);
|
| 311 | if (realm->parent) {
|
| 312 | list_del_init(&realm->child_item);
|
| 313 | ceph_put_snap_realm(mdsc, realm->parent);
|
| 314 | }
|
| 315 | realm->parent_ino = parentino;
|
| 316 | realm->parent = parent;
|
| 317 | list_add(&realm->child_item, &parent->children);
|
| 318 | return 1;
|
| 319 | }
|
| 320 |
|
| 321 |
|
| 322 | static int cmpu64_rev(const void *a, const void *b)
|
| 323 | {
|
| 324 | if (*(u64 *)a < *(u64 *)b)
|
| 325 | return 1;
|
| 326 | if (*(u64 *)a > *(u64 *)b)
|
| 327 | return -1;
|
| 328 | return 0;
|
| 329 | }
|
| 330 |
|
| 331 |
|
| 332 | |
| 333 | * build the snap context for a given realm.
|
| 334 |
|
| 335 | static int build_snap_context(struct ceph_mds_client *mdsc,
|
| 336 | struct ceph_snap_realm *realm,
|
| 337 | struct list_head *realm_queue,
|
| 338 | struct list_head *dirty_realms)
|
| 339 | {
|
| 340 | struct ceph_client *cl = mdsc->fsc->client;
|
| 341 | struct ceph_snap_realm *parent = realm->parent;
|
| 342 | struct ceph_snap_context *snapc;
|
| 343 | int err = 0;
|
| 344 | u32 num = realm->num_prior_parent_snaps + realm->num_snaps;
|
| 345 |
|
| 346 | |
| 347 | * build parent context, if it hasn't been built.
|
| 348 | * conservatively estimate that all parent snaps might be
|
| 349 | * included by us.
|
| 350 |
|
| 351 | if (parent) {
|
| 352 | if (!parent->cached_context) {
|
| 353 |
|
| 354 | list_add(&parent->rebuild_item, realm_queue);
|
| 355 | return 1;
|
| 356 | }
|
| 357 | num += parent->cached_context->num_snaps;
|
| 358 | }
|
| 359 |
|
| 360 | |
| 361 | matches realm seq, and my parents' does to. (this works
|
| 362 | because we rebuild_snap_realms() works _downward_ in
|
| 363 | hierarchy after each update.)
|
| 364 | if (realm->cached_context &&
|
| 365 | realm->cached_context->seq == realm->seq &&
|
| 366 | (!parent ||
|
| 367 | realm->cached_context->seq >= parent->cached_context->seq)) {
|
| 368 | doutc(cl, "%llx %p: %p seq %lld (%u snaps) (unchanged)\n",
|
| 369 | realm->ino, realm, realm->cached_context,
|
| 370 | realm->cached_context->seq,
|
| 371 | (unsigned int)realm->cached_context->num_snaps);
|
| 372 | return 0;
|
| 373 | }
|
| 374 |
|
| 375 |
|
| 376 | err = -ENOMEM;
|
| 377 | if ((size_t)num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
|
| 378 | goto fail;
|
| 379 | snapc = ceph_create_snap_context(num, GFP_NOFS);
|
| 380 | if (!snapc)
|
| 381 | goto fail;
|
| 382 |
|
| 383 |
|
| 384 | num = 0;
|
| 385 | snapc->seq = realm->seq;
|
| 386 | if (parent) {
|
| 387 | u32 i;
|
| 388 |
|
| 389 | |
| 390 | parent became my parent
|
| 391 | for (i = 0; i < parent->cached_context->num_snaps; i++)
|
| 392 | if (parent->cached_context->snaps[i] >=
|
| 393 | realm->parent_since)
|
| 394 | snapc->snaps[num++] =
|
| 395 | parent->cached_context->snaps[i];
|
| 396 | if (parent->cached_context->seq > snapc->seq)
|
| 397 | snapc->seq = parent->cached_context->seq;
|
| 398 | }
|
| 399 | memcpy(snapc->snaps + num, realm->snaps,
|
| 400 | sizeof(u64)*realm->num_snaps);
|
| 401 | num += realm->num_snaps;
|
| 402 | memcpy(snapc->snaps + num, realm->prior_parent_snaps,
|
| 403 | sizeof(u64)*realm->num_prior_parent_snaps);
|
| 404 | num += realm->num_prior_parent_snaps;
|
| 405 |
|
| 406 | sort(snapc->snaps, num, sizeof(u64), cmpu64_rev, NULL);
|
| 407 | snapc->num_snaps = num;
|
| 408 | doutc(cl, "%llx %p: %p seq %lld (%u snaps)\n", realm->ino, realm,
|
| 409 | snapc, snapc->seq, (unsigned int) snapc->num_snaps);
|
| 410 |
|
| 411 | ceph_put_snap_context(realm->cached_context);
|
| 412 | realm->cached_context = snapc;
|
| 413 |
|
| 414 | list_add_tail(&realm->dirty_item, dirty_realms);
|
| 415 | return 0;
|
| 416 |
|
| 417 | fail:
|
| 418 | |
| 419 | * if we fail, clear old (incorrect) cached_context... hopefully
|
| 420 | * we'll have better luck building it later
|
| 421 |
|
| 422 | if (realm->cached_context) {
|
| 423 | ceph_put_snap_context(realm->cached_context);
|
| 424 | realm->cached_context = NULL;
|
| 425 | }
|
| 426 | pr_err_client(cl, "%llx %p fail %d\n", realm->ino, realm, err);
|
| 427 | return err;
|
| 428 | }
|
| 429 |
|
| 430 | |
| 431 | * rebuild snap context for the given realm and all of its children.
|
| 432 |
|
| 433 | static void rebuild_snap_realms(struct ceph_mds_client *mdsc,
|
| 434 | struct ceph_snap_realm *realm,
|
| 435 | struct list_head *dirty_realms)
|
| 436 | {
|
| 437 | struct ceph_client *cl = mdsc->fsc->client;
|
| 438 | LIST_HEAD(realm_queue);
|
| 439 | int last = 0;
|
| 440 | bool skip = false;
|
| 441 |
|
| 442 | list_add_tail(&realm->rebuild_item, &realm_queue);
|
| 443 |
|
| 444 | while (!list_empty(&realm_queue)) {
|
| 445 | struct ceph_snap_realm *_realm, *child;
|
| 446 |
|
| 447 | _realm = list_first_entry(&realm_queue,
|
| 448 | struct ceph_snap_realm,
|
| 449 | rebuild_item);
|
| 450 |
|
| 451 | |
| 452 | * If the last building failed dues to memory
|
| 453 | * issue, just empty the realm_queue and return
|
| 454 | * to avoid infinite loop.
|
| 455 |
|
| 456 | if (last < 0) {
|
| 457 | list_del_init(&_realm->rebuild_item);
|
| 458 | continue;
|
| 459 | }
|
| 460 |
|
| 461 | last = build_snap_context(mdsc, _realm, &realm_queue,
|
| 462 | dirty_realms);
|
| 463 | doutc(cl, "%llx %p, %s\n", realm->ino, realm,
|
| 464 | last > 0 ? "is deferred" : !last ? "succeeded" : "failed");
|
| 465 |
|
| 466 |
|
| 467 | list_for_each_entry(child, &_realm->children, child_item) {
|
| 468 | if (!list_empty(&child->rebuild_item)) {
|
| 469 | skip = true;
|
| 470 | break;
|
| 471 | }
|
| 472 | }
|
| 473 |
|
| 474 | if (!skip) {
|
| 475 | list_for_each_entry(child, &_realm->children, child_item)
|
| 476 | list_add_tail(&child->rebuild_item, &realm_queue);
|
| 477 | }
|
| 478 |
|
| 479 |
|
| 480 | if (last <= 0)
|
| 481 | list_del_init(&_realm->rebuild_item);
|
| 482 | }
|
| 483 | }
|
| 484 |
|
| 485 |
|
| 486 | |
| 487 | * helper to allocate and decode an array of snapids. free prior
|
| 488 | * instance, if any.
|
| 489 |
|
| 490 | static int dup_array(u64 **dst, __le64 *src, u32 num)
|
| 491 | {
|
| 492 | u32 i;
|
| 493 |
|
| 494 | kfree(*dst);
|
| 495 | if (num) {
|
| 496 | *dst = kcalloc(num, sizeof(u64), GFP_NOFS);
|
| 497 | if (!*dst)
|
| 498 | return -ENOMEM;
|
| 499 | for (i = 0; i < num; i++)
|
| 500 | (*dst)[i] = get_unaligned_le64(src + i);
|
| 501 | } else {
|
| 502 | *dst = NULL;
|
| 503 | }
|
| 504 | return 0;
|
| 505 | }
|
| 506 |
|
| 507 | static bool has_new_snaps(struct ceph_snap_context *o,
|
| 508 | struct ceph_snap_context *n)
|
| 509 | {
|
| 510 | if (n->num_snaps == 0)
|
| 511 | return false;
|
| 512 |
|
| 513 | return n->snaps[0] > o->seq;
|
| 514 | }
|
| 515 |
|
| 516 | |
| 517 | * When a snapshot is applied, the size/mtime inode metadata is queued
|
| 518 | * in a ceph_cap_snap (one for each snapshot) until writeback
|
| 519 | * completes and the metadata can be flushed back to the MDS.
|
| 520 | *
|
| 521 | * However, if a (sync) write is currently in-progress when we apply
|
| 522 | * the snapshot, we have to wait until the write succeeds or fails
|
| 523 | * (and a final size/mtime is known). In this case the
|
| 524 | * cap_snap->writing = 1, and is said to be "pending." When the write
|
| 525 | * finishes, we __ceph_finish_cap_snap().
|
| 526 | *
|
| 527 | * Caller must hold snap_rwsem for read (i.e., the realm topology won't
|
| 528 | * change).
|
| 529 |
|
| 530 | static void ceph_queue_cap_snap(struct ceph_inode_info *ci,
|
| 531 | struct ceph_cap_snap **pcapsnap)
|
| 532 | {
|
| 533 | struct inode *inode = &ci->netfs.inode;
|
| 534 | struct ceph_client *cl = ceph_inode_to_client(inode);
|
| 535 | struct ceph_snap_context *old_snapc, *new_snapc;
|
| 536 | struct ceph_cap_snap *capsnap = *pcapsnap;
|
| 537 | struct ceph_buffer *old_blob = NULL;
|
| 538 | int used, dirty;
|
| 539 |
|
| 540 | spin_lock(&ci->i_ceph_lock);
|
| 541 | used = __ceph_caps_used(ci);
|
| 542 | dirty = __ceph_caps_dirty(ci);
|
| 543 |
|
| 544 | old_snapc = ci->i_head_snapc;
|
| 545 | new_snapc = ci->i_snap_realm->cached_context;
|
| 546 |
|
| 547 | |
| 548 | * If there is a write in progress, treat that as a dirty Fw,
|
| 549 | * even though it hasn't completed yet; by the time we finish
|
| 550 | * up this capsnap it will be.
|
| 551 |
|
| 552 | if (used & CEPH_CAP_FILE_WR)
|
| 553 | dirty |= CEPH_CAP_FILE_WR;
|
| 554 |
|
| 555 | if (__ceph_have_pending_cap_snap(ci)) {
|
| 556 | |
| 557 | as no new writes are allowed to start when pending, so any
|
| 558 | writes in progress now were started before the previous
|
| 559 | cap_snap. lucky us.
|
| 560 | doutc(cl, "%p %llx.%llx already pending\n", inode,
|
| 561 | ceph_vinop(inode));
|
| 562 | goto update_snapc;
|
| 563 | }
|
| 564 | if (ci->i_wrbuffer_ref_head == 0 &&
|
| 565 | !(dirty & (CEPH_CAP_ANY_EXCL|CEPH_CAP_FILE_WR))) {
|
| 566 | doutc(cl, "%p %llx.%llx nothing dirty|writing\n", inode,
|
| 567 | ceph_vinop(inode));
|
| 568 | goto update_snapc;
|
| 569 | }
|
| 570 |
|
| 571 | BUG_ON(!old_snapc);
|
| 572 |
|
| 573 | |
| 574 | * There is no need to send FLUSHSNAP message to MDS if there is
|
| 575 | * no new snapshot. But when there is dirty pages or on-going
|
| 576 | * writes, we still need to create cap_snap. cap_snap is needed
|
| 577 | * by the write path and page writeback path.
|
| 578 | *
|
| 579 | * also see ceph_try_drop_cap_snap()
|
| 580 |
|
| 581 | if (has_new_snaps(old_snapc, new_snapc)) {
|
| 582 | if (dirty & (CEPH_CAP_ANY_EXCL|CEPH_CAP_FILE_WR))
|
| 583 | capsnap->need_flush = true;
|
| 584 | } else {
|
| 585 | if (!(used & CEPH_CAP_FILE_WR) &&
|
| 586 | ci->i_wrbuffer_ref_head == 0) {
|
| 587 | doutc(cl, "%p %llx.%llx no new_snap|dirty_page|writing\n",
|
| 588 | inode, ceph_vinop(inode));
|
| 589 | goto update_snapc;
|
| 590 | }
|
| 591 | }
|
| 592 |
|
| 593 | doutc(cl, "%p %llx.%llx cap_snap %p queuing under %p %s %s\n",
|
| 594 | inode, ceph_vinop(inode), capsnap, old_snapc,
|
| 595 | ceph_cap_string(dirty), capsnap->need_flush ? "" : "no_flush");
|
| 596 | ihold(inode);
|
| 597 |
|
| 598 | capsnap->follows = old_snapc->seq;
|
| 599 | capsnap->issued = __ceph_caps_issued(ci, NULL);
|
| 600 | capsnap->dirty = dirty;
|
| 601 |
|
| 602 | capsnap->mode = inode->i_mode;
|
| 603 | capsnap->uid = inode->i_uid;
|
| 604 | capsnap->gid = inode->i_gid;
|
| 605 |
|
| 606 | if (dirty & CEPH_CAP_XATTR_EXCL) {
|
| 607 | old_blob = __ceph_build_xattrs_blob(ci);
|
| 608 | capsnap->xattr_blob =
|
| 609 | ceph_buffer_get(ci->i_xattrs.blob);
|
| 610 | capsnap->xattr_version = ci->i_xattrs.version;
|
| 611 | } else {
|
| 612 | capsnap->xattr_blob = NULL;
|
| 613 | capsnap->xattr_version = 0;
|
| 614 | }
|
| 615 |
|
| 616 | capsnap->inline_data = ci->i_inline_version != CEPH_INLINE_NONE;
|
| 617 |
|
| 618 | |
| 619 | all subsequent writes page dirties occur _after_ this
|
| 620 | snapshot.
|
| 621 | capsnap->dirty_pages = ci->i_wrbuffer_ref_head;
|
| 622 | ci->i_wrbuffer_ref_head = 0;
|
| 623 | capsnap->context = old_snapc;
|
| 624 | list_add_tail(&capsnap->ci_item, &ci->i_cap_snaps);
|
| 625 |
|
| 626 | if (used & CEPH_CAP_FILE_WR) {
|
| 627 | doutc(cl, "%p %llx.%llx cap_snap %p snapc %p seq %llu used WR,"
|
| 628 | " now pending\n", inode, ceph_vinop(inode), capsnap,
|
| 629 | old_snapc, old_snapc->seq);
|
| 630 | capsnap->writing = 1;
|
| 631 | } else {
|
| 632 |
|
| 633 | __ceph_finish_cap_snap(ci, capsnap);
|
| 634 | }
|
| 635 | *pcapsnap = NULL;
|
| 636 | old_snapc = NULL;
|
| 637 |
|
| 638 | update_snapc:
|
| 639 | if (ci->i_wrbuffer_ref_head == 0 &&
|
| 640 | ci->i_wr_ref == 0 &&
|
| 641 | ci->i_dirty_caps == 0 &&
|
| 642 | ci->i_flushing_caps == 0) {
|
| 643 | ci->i_head_snapc = NULL;
|
| 644 | } else {
|
| 645 | ci->i_head_snapc = ceph_get_snap_context(new_snapc);
|
| 646 | doutc(cl, " new snapc is %p\n", new_snapc);
|
| 647 | }
|
| 648 | spin_unlock(&ci->i_ceph_lock);
|
| 649 |
|
| 650 | ceph_buffer_put(old_blob);
|
| 651 | ceph_put_snap_context(old_snapc);
|
| 652 | }
|
| 653 |
|
| 654 | |
| 655 | * Finalize the size, mtime for a cap_snap.. that is, settle on final values
|
| 656 | * to be used for the snapshot, to be flushed back to the mds.
|
| 657 | *
|
| 658 | * If capsnap can now be flushed, add to snap_flush list, and return 1.
|
| 659 | *
|
| 660 | * Caller must hold i_ceph_lock.
|
| 661 |
|
| 662 | int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
|
| 663 | struct ceph_cap_snap *capsnap)
|
| 664 | {
|
| 665 | struct inode *inode = &ci->netfs.inode;
|
| 666 | struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
|
| 667 | struct ceph_client *cl = mdsc->fsc->client;
|
| 668 |
|
| 669 | BUG_ON(capsnap->writing);
|
| 670 | capsnap->size = i_size_read(inode);
|
| 671 | capsnap->mtime = inode_get_mtime(inode);
|
| 672 | capsnap->atime = inode_get_atime(inode);
|
| 673 | capsnap->ctime = inode_get_ctime(inode);
|
| 674 | capsnap->btime = ci->i_btime;
|
| 675 | capsnap->change_attr = inode_peek_iversion_raw(inode);
|
| 676 | capsnap->time_warp_seq = ci->i_time_warp_seq;
|
| 677 | capsnap->truncate_size = ci->i_truncate_size;
|
| 678 | capsnap->truncate_seq = ci->i_truncate_seq;
|
| 679 | if (capsnap->dirty_pages) {
|
| 680 | doutc(cl, "%p %llx.%llx cap_snap %p snapc %p %llu %s "
|
| 681 | "s=%llu still has %d dirty pages\n", inode,
|
| 682 | ceph_vinop(inode), capsnap, capsnap->context,
|
| 683 | capsnap->context->seq,
|
| 684 | ceph_cap_string(capsnap->dirty),
|
| 685 | capsnap->size, capsnap->dirty_pages);
|
| 686 | return 0;
|
| 687 | }
|
| 688 |
|
| 689 | |
| 690 | * Defer flushing the capsnap if the dirty buffer not flushed yet.
|
| 691 | * And trigger to flush the buffer immediately.
|
| 692 |
|
| 693 | if (ci->i_wrbuffer_ref) {
|
| 694 | doutc(cl, "%p %llx.%llx cap_snap %p snapc %p %llu %s "
|
| 695 | "s=%llu used WRBUFFER, delaying\n", inode,
|
| 696 | ceph_vinop(inode), capsnap, capsnap->context,
|
| 697 | capsnap->context->seq, ceph_cap_string(capsnap->dirty),
|
| 698 | capsnap->size);
|
| 699 | ceph_queue_writeback(inode);
|
| 700 | return 0;
|
| 701 | }
|
| 702 |
|
| 703 | set_bit(CEPH_I_FLUSH_SNAPS_BIT, &ci->i_ceph_flags);
|
| 704 | doutc(cl, "%p %llx.%llx cap_snap %p snapc %p %llu %s s=%llu\n",
|
| 705 | inode, ceph_vinop(inode), capsnap, capsnap->context,
|
| 706 | capsnap->context->seq, ceph_cap_string(capsnap->dirty),
|
| 707 | capsnap->size);
|
| 708 |
|
| 709 | spin_lock(&mdsc->snap_flush_lock);
|
| 710 | if (list_empty(&ci->i_snap_flush_item)) {
|
| 711 | ihold(inode);
|
| 712 | list_add_tail(&ci->i_snap_flush_item, &mdsc->snap_flush_list);
|
| 713 | }
|
| 714 | spin_unlock(&mdsc->snap_flush_lock);
|
| 715 | return 1;
|
| 716 | }
|
| 717 |
|
| 718 | |
| 719 | * Queue cap_snaps for snap writeback for this realm and its children.
|
| 720 | * Called under snap_rwsem, so realm topology won't change.
|
| 721 |
|
| 722 | static void queue_realm_cap_snaps(struct ceph_mds_client *mdsc,
|
| 723 | struct ceph_snap_realm *realm)
|
| 724 | {
|
| 725 | struct ceph_client *cl = mdsc->fsc->client;
|
| 726 | struct ceph_inode_info *ci;
|
| 727 | struct inode *lastinode = NULL;
|
| 728 | struct ceph_cap_snap *capsnap = NULL;
|
| 729 |
|
| 730 | doutc(cl, "%p %llx inode\n", realm, realm->ino);
|
| 731 |
|
| 732 | spin_lock(&realm->inodes_with_caps_lock);
|
| 733 | list_for_each_entry(ci, &realm->inodes_with_caps, i_snap_realm_item) {
|
| 734 | struct inode *inode = igrab(&ci->netfs.inode);
|
| 735 | if (!inode)
|
| 736 | continue;
|
| 737 | spin_unlock(&realm->inodes_with_caps_lock);
|
| 738 | iput(lastinode);
|
| 739 | lastinode = inode;
|
| 740 |
|
| 741 | |
| 742 | * Allocate the capsnap memory outside of ceph_queue_cap_snap()
|
| 743 | * to reduce very possible but unnecessary frequently memory
|
| 744 | * allocate/free in this loop.
|
| 745 |
|
| 746 | if (!capsnap) {
|
| 747 | capsnap = kmem_cache_zalloc(ceph_cap_snap_cachep, GFP_NOFS);
|
| 748 | if (!capsnap) {
|
| 749 | pr_err_client(cl,
|
| 750 | "ENOMEM allocating ceph_cap_snap on %p\n",
|
| 751 | inode);
|
| 752 | return;
|
| 753 | }
|
| 754 | }
|
| 755 | capsnap->cap_flush.is_capsnap = true;
|
| 756 | refcount_set(&capsnap->nref, 1);
|
| 757 | INIT_LIST_HEAD(&capsnap->cap_flush.i_list);
|
| 758 | INIT_LIST_HEAD(&capsnap->cap_flush.g_list);
|
| 759 | INIT_LIST_HEAD(&capsnap->ci_item);
|
| 760 |
|
| 761 | ceph_queue_cap_snap(ci, &capsnap);
|
| 762 | spin_lock(&realm->inodes_with_caps_lock);
|
| 763 | }
|
| 764 | spin_unlock(&realm->inodes_with_caps_lock);
|
| 765 | iput(lastinode);
|
| 766 |
|
| 767 | if (capsnap)
|
| 768 | kmem_cache_free(ceph_cap_snap_cachep, capsnap);
|
| 769 | doutc(cl, "%p %llx done\n", realm, realm->ino);
|
| 770 | }
|
| 771 |
|
| 772 | |
| 773 | * Parse and apply a snapblob "snap trace" from the MDS. This specifies
|
| 774 | * the snap realm parameters from a given realm and all of its ancestors,
|
| 775 | * up to the root.
|
| 776 | *
|
| 777 | * Caller must hold snap_rwsem for write.
|
| 778 |
|
| 779 | int ceph_update_snap_trace(struct ceph_mds_client *mdsc,
|
| 780 | void *p, void *e, bool deletion,
|
| 781 | struct ceph_snap_realm **realm_ret)
|
| 782 | {
|
| 783 | struct ceph_client *cl = mdsc->fsc->client;
|
| 784 | struct ceph_mds_snap_realm *ri;
|
| 785 | __le64 *snaps;
|
| 786 | __le64 *prior_parent_snaps;
|
| 787 | struct ceph_snap_realm *realm;
|
| 788 | struct ceph_snap_realm *first_realm = NULL;
|
| 789 | struct ceph_snap_realm *realm_to_rebuild = NULL;
|
| 790 | struct ceph_client *client = mdsc->fsc->client;
|
| 791 | int rebuild_snapcs;
|
| 792 | int err = -ENOMEM;
|
| 793 | int ret;
|
| 794 | LIST_HEAD(dirty_realms);
|
| 795 |
|
| 796 | lockdep_assert_held_write(&mdsc->snap_rwsem);
|
| 797 |
|
| 798 | doutc(cl, "deletion=%d\n", deletion);
|
| 799 | more:
|
| 800 | realm = NULL;
|
| 801 | rebuild_snapcs = 0;
|
| 802 | ceph_decode_need(&p, e, sizeof(*ri), bad);
|
| 803 | ri = p;
|
| 804 | p += sizeof(*ri);
|
| 805 | ceph_decode_need(&p, e, sizeof(u64)*(le32_to_cpu(ri->num_snaps) +
|
| 806 | le32_to_cpu(ri->num_prior_parent_snaps)), bad);
|
| 807 | snaps = p;
|
| 808 | p += sizeof(u64) * le32_to_cpu(ri->num_snaps);
|
| 809 | prior_parent_snaps = p;
|
| 810 | p += sizeof(u64) * le32_to_cpu(ri->num_prior_parent_snaps);
|
| 811 |
|
| 812 | realm = ceph_lookup_snap_realm(mdsc, le64_to_cpu(ri->ino));
|
| 813 | if (!realm) {
|
| 814 | realm = ceph_create_snap_realm(mdsc, le64_to_cpu(ri->ino));
|
| 815 | if (IS_ERR(realm)) {
|
| 816 | err = PTR_ERR(realm);
|
| 817 | goto fail;
|
| 818 | }
|
| 819 | }
|
| 820 |
|
| 821 |
|
| 822 | err = adjust_snap_realm_parent(mdsc, realm, le64_to_cpu(ri->parent));
|
| 823 | if (err < 0)
|
| 824 | goto fail;
|
| 825 | rebuild_snapcs += err;
|
| 826 |
|
| 827 | if (le64_to_cpu(ri->seq) > realm->seq) {
|
| 828 | doutc(cl, "updating %llx %p %lld -> %lld\n", realm->ino,
|
| 829 | realm, realm->seq, le64_to_cpu(ri->seq));
|
| 830 |
|
| 831 | realm->seq = le64_to_cpu(ri->seq);
|
| 832 | realm->created = le64_to_cpu(ri->created);
|
| 833 | realm->parent_since = le64_to_cpu(ri->parent_since);
|
| 834 |
|
| 835 | realm->num_snaps = le32_to_cpu(ri->num_snaps);
|
| 836 | err = dup_array(&realm->snaps, snaps, realm->num_snaps);
|
| 837 | if (err < 0)
|
| 838 | goto fail;
|
| 839 |
|
| 840 | realm->num_prior_parent_snaps =
|
| 841 | le32_to_cpu(ri->num_prior_parent_snaps);
|
| 842 | err = dup_array(&realm->prior_parent_snaps, prior_parent_snaps,
|
| 843 | realm->num_prior_parent_snaps);
|
| 844 | if (err < 0)
|
| 845 | goto fail;
|
| 846 |
|
| 847 | if (realm->seq > mdsc->last_snap_seq)
|
| 848 | mdsc->last_snap_seq = realm->seq;
|
| 849 |
|
| 850 | rebuild_snapcs = 1;
|
| 851 | } else if (!realm->cached_context) {
|
| 852 | doutc(cl, "%llx %p seq %lld new\n", realm->ino, realm,
|
| 853 | realm->seq);
|
| 854 | rebuild_snapcs = 1;
|
| 855 | } else {
|
| 856 | doutc(cl, "%llx %p seq %lld unchanged\n", realm->ino, realm,
|
| 857 | realm->seq);
|
| 858 | }
|
| 859 |
|
| 860 | doutc(cl, "done with %llx %p, rebuild_snapcs=%d, %p %p\n", realm->ino,
|
| 861 | realm, rebuild_snapcs, p, e);
|
| 862 |
|
| 863 | |
| 864 | * this will always track the uppest parent realm from which
|
| 865 | * we need to rebuild the snapshot contexts _downward_ in
|
| 866 | * hierarchy.
|
| 867 |
|
| 868 | if (rebuild_snapcs)
|
| 869 | realm_to_rebuild = realm;
|
| 870 |
|
| 871 |
|
| 872 | if (realm_to_rebuild && p >= e)
|
| 873 | rebuild_snap_realms(mdsc, realm_to_rebuild, &dirty_realms);
|
| 874 |
|
| 875 | if (!first_realm)
|
| 876 | first_realm = realm;
|
| 877 | else
|
| 878 | ceph_put_snap_realm(mdsc, realm);
|
| 879 |
|
| 880 | if (p < e)
|
| 881 | goto more;
|
| 882 |
|
| 883 | |
| 884 | * queue cap snaps _after_ we've built the new snap contexts,
|
| 885 | * so that i_head_snapc can be set appropriately.
|
| 886 |
|
| 887 | while (!list_empty(&dirty_realms)) {
|
| 888 | realm = list_first_entry(&dirty_realms, struct ceph_snap_realm,
|
| 889 | dirty_item);
|
| 890 | list_del_init(&realm->dirty_item);
|
| 891 | queue_realm_cap_snaps(mdsc, realm);
|
| 892 | }
|
| 893 |
|
| 894 | if (realm_ret)
|
| 895 | *realm_ret = first_realm;
|
| 896 | else
|
| 897 | ceph_put_snap_realm(mdsc, first_realm);
|
| 898 |
|
| 899 | __cleanup_empty_realms(mdsc);
|
| 900 | return 0;
|
| 901 |
|
| 902 | bad:
|
| 903 | err = -EIO;
|
| 904 | fail:
|
| 905 | if (realm && !IS_ERR(realm))
|
| 906 | ceph_put_snap_realm(mdsc, realm);
|
| 907 | if (first_realm)
|
| 908 | ceph_put_snap_realm(mdsc, first_realm);
|
| 909 | pr_err_client(cl, "error %d\n", err);
|
| 910 |
|
| 911 | |
| 912 | * When receiving a corrupted snap trace we don't know what
|
| 913 | * exactly has happened in MDS side. And we shouldn't continue
|
| 914 | * writing to OSD, which may corrupt the snapshot contents.
|
| 915 | *
|
| 916 | * Just try to blocklist this kclient and then this kclient
|
| 917 | * must be remounted to continue after the corrupted metadata
|
| 918 | * fixed in the MDS side.
|
| 919 |
|
| 920 | WRITE_ONCE(mdsc->fsc->mount_state, CEPH_MOUNT_FENCE_IO);
|
| 921 | ret = ceph_monc_blocklist_add(&client->monc, &client->msgr.inst.addr);
|
| 922 | if (ret)
|
| 923 | pr_err_client(cl, "failed to blocklist %s: %d\n",
|
| 924 | ceph_pr_addr(&client->msgr.inst.addr), ret);
|
| 925 |
|
| 926 | WARN(1, "[client.%lld] %s %s%sdo remount to continue%s",
|
| 927 | client->monc.auth->global_id, __func__,
|
| 928 | ret ? "" : ceph_pr_addr(&client->msgr.inst.addr),
|
| 929 | ret ? "" : " was blocklisted, ",
|
| 930 | err == -EIO ? " after corrupted snaptrace is fixed" : "");
|
| 931 |
|
| 932 | return err;
|
| 933 | }
|
| 934 |
|
| 935 |
|
| 936 | |
| 937 | * Send any cap_snaps that are queued for flush. Try to carry
|
| 938 | * s_mutex across multiple snap flushes to avoid locking overhead.
|
| 939 | *
|
| 940 | * Caller holds no locks.
|
| 941 |
|
| 942 | static void flush_snaps(struct ceph_mds_client *mdsc)
|
| 943 | {
|
| 944 | struct ceph_client *cl = mdsc->fsc->client;
|
| 945 | struct ceph_inode_info *ci;
|
| 946 | struct inode *inode;
|
| 947 | struct ceph_mds_session *session = NULL;
|
| 948 |
|
| 949 | doutc(cl, "begin\n");
|
| 950 | spin_lock(&mdsc->snap_flush_lock);
|
| 951 | while (!list_empty(&mdsc->snap_flush_list)) {
|
| 952 | ci = list_first_entry(&mdsc->snap_flush_list,
|
| 953 | struct ceph_inode_info, i_snap_flush_item);
|
| 954 | inode = &ci->netfs.inode;
|
| 955 | ihold(inode);
|
| 956 | spin_unlock(&mdsc->snap_flush_lock);
|
| 957 | ceph_flush_snaps(ci, &session);
|
| 958 | iput(inode);
|
| 959 | spin_lock(&mdsc->snap_flush_lock);
|
| 960 | }
|
| 961 | spin_unlock(&mdsc->snap_flush_lock);
|
| 962 |
|
| 963 | ceph_put_mds_session(session);
|
| 964 | doutc(cl, "done\n");
|
| 965 | }
|
| 966 |
|
| 967 | |
| 968 | * ceph_change_snap_realm - change the snap_realm for an inode
|
| 969 | * @inode: inode to move to new snap realm
|
| 970 | * @realm: new realm to move inode into (may be NULL)
|
| 971 | *
|
| 972 | * Detach an inode from its old snaprealm (if any) and attach it to
|
| 973 | * the new snaprealm (if any). The old snap realm reference held by
|
| 974 | * the inode is put. If realm is non-NULL, then the caller's reference
|
| 975 | * to it is taken over by the inode.
|
| 976 |
|
| 977 | void ceph_change_snap_realm(struct inode *inode, struct ceph_snap_realm *realm)
|
| 978 | {
|
| 979 | struct ceph_inode_info *ci = ceph_inode(inode);
|
| 980 | struct ceph_mds_client *mdsc = ceph_inode_to_fs_client(inode)->mdsc;
|
| 981 | struct ceph_snap_realm *oldrealm = ci->i_snap_realm;
|
| 982 |
|
| 983 | lockdep_assert_held(&ci->i_ceph_lock);
|
| 984 |
|
| 985 | if (oldrealm) {
|
| 986 | spin_lock(&oldrealm->inodes_with_caps_lock);
|
| 987 | list_del_init(&ci->i_snap_realm_item);
|
| 988 | if (oldrealm->ino == ci->i_vino.ino)
|
| 989 | oldrealm->inode = NULL;
|
| 990 | spin_unlock(&oldrealm->inodes_with_caps_lock);
|
| 991 | ceph_put_snap_realm(mdsc, oldrealm);
|
| 992 | }
|
| 993 |
|
| 994 | ci->i_snap_realm = realm;
|
| 995 |
|
| 996 | if (realm) {
|
| 997 | spin_lock(&realm->inodes_with_caps_lock);
|
| 998 | list_add(&ci->i_snap_realm_item, &realm->inodes_with_caps);
|
| 999 | if (realm->ino == ci->i_vino.ino)
|
| 1000 | realm->inode = inode;
|
| 1001 | spin_unlock(&realm->inodes_with_caps_lock);
|
| 1002 | }
|
| 1003 | }
|
| 1004 |
|
| 1005 | |
| 1006 | * Handle a snap notification from the MDS.
|
| 1007 | *
|
| 1008 | * This can take two basic forms: the simplest is just a snap creation
|
| 1009 | * or deletion notification on an existing realm. This should update the
|
| 1010 | * realm and its children.
|
| 1011 | *
|
| 1012 | * The more difficult case is realm creation, due to snap creation at a
|
| 1013 | * new point in the file hierarchy, or due to a rename that moves a file or
|
| 1014 | * directory into another realm.
|
| 1015 |
|
| 1016 | void ceph_handle_snap(struct ceph_mds_client *mdsc,
|
| 1017 | struct ceph_mds_session *session,
|
| 1018 | struct ceph_msg *msg)
|
| 1019 | {
|
| 1020 | struct ceph_client *cl = mdsc->fsc->client;
|
| 1021 | struct super_block *sb = mdsc->fsc->sb;
|
| 1022 | int mds = session->s_mds;
|
| 1023 | u64 split;
|
| 1024 | int op;
|
| 1025 | int trace_len;
|
| 1026 | struct ceph_snap_realm *realm = NULL;
|
| 1027 | void *p = msg->front.iov_base;
|
| 1028 | void *e = p + msg->front.iov_len;
|
| 1029 | struct ceph_mds_snap_head *h;
|
| 1030 | int num_split_inos, num_split_realms;
|
| 1031 | __le64 *split_inos = NULL, *split_realms = NULL;
|
| 1032 | int i;
|
| 1033 | int locked_rwsem = 0;
|
| 1034 | bool close_sessions = false;
|
| 1035 |
|
| 1036 | if (!ceph_inc_mds_stopping_blocker(mdsc, session))
|
| 1037 | return;
|
| 1038 |
|
| 1039 |
|
| 1040 | if (msg->front.iov_len < sizeof(*h))
|
| 1041 | goto bad;
|
| 1042 | h = p;
|
| 1043 | op = le32_to_cpu(h->op);
|
| 1044 | split = le64_to_cpu(h->split); |
| 1045 | * existing realm
|
| 1046 | num_split_inos = le32_to_cpu(h->num_split_inos);
|
| 1047 | num_split_realms = le32_to_cpu(h->num_split_realms);
|
| 1048 | trace_len = le32_to_cpu(h->trace_len);
|
| 1049 | p += sizeof(*h);
|
| 1050 |
|
| 1051 | doutc(cl, "from mds%d op %s split %llx tracelen %d\n", mds,
|
| 1052 | ceph_snap_op_name(op), split, trace_len);
|
| 1053 |
|
| 1054 | down_write(&mdsc->snap_rwsem);
|
| 1055 | locked_rwsem = 1;
|
| 1056 |
|
| 1057 | if (op == CEPH_SNAP_OP_SPLIT) {
|
| 1058 | struct ceph_mds_snap_realm *ri;
|
| 1059 |
|
| 1060 | |
| 1061 | * A "split" breaks part of an existing realm off into
|
| 1062 | * a new realm. The MDS provides a list of inodes
|
| 1063 | * (with caps) and child realms that belong to the new
|
| 1064 | * child.
|
| 1065 |
|
| 1066 | split_inos = p;
|
| 1067 | p += sizeof(u64) * num_split_inos;
|
| 1068 | split_realms = p;
|
| 1069 | p += sizeof(u64) * num_split_realms;
|
| 1070 | ceph_decode_need(&p, e, sizeof(*ri), bad);
|
| 1071 | |
| 1072 | * advance p, as the realm update will occur below in
|
| 1073 | * ceph_update_snap_trace.
|
| 1074 | ri = p;
|
| 1075 |
|
| 1076 | realm = ceph_lookup_snap_realm(mdsc, split);
|
| 1077 | if (!realm) {
|
| 1078 | realm = ceph_create_snap_realm(mdsc, split);
|
| 1079 | if (IS_ERR(realm))
|
| 1080 | goto out;
|
| 1081 | }
|
| 1082 |
|
| 1083 | doutc(cl, "splitting snap_realm %llx %p\n", realm->ino, realm);
|
| 1084 | for (i = 0; i < num_split_inos; i++) {
|
| 1085 | struct ceph_vino vino = {
|
| 1086 | .ino = le64_to_cpu(split_inos[i]),
|
| 1087 | .snap = CEPH_NOSNAP,
|
| 1088 | };
|
| 1089 | struct inode *inode = ceph_find_inode(sb, vino);
|
| 1090 | struct ceph_inode_info *ci;
|
| 1091 |
|
| 1092 | if (!inode)
|
| 1093 | continue;
|
| 1094 | ci = ceph_inode(inode);
|
| 1095 |
|
| 1096 | spin_lock(&ci->i_ceph_lock);
|
| 1097 | if (!ci->i_snap_realm)
|
| 1098 | goto skip_inode;
|
| 1099 | |
| 1100 | * If this inode belongs to a realm that was
|
| 1101 | * created after our new realm, we experienced
|
| 1102 | * a race (due to another split notifications
|
| 1103 | * arriving from a different MDS). So skip
|
| 1104 | * this inode.
|
| 1105 |
|
| 1106 | if (ci->i_snap_realm->created >
|
| 1107 | le64_to_cpu(ri->created)) {
|
| 1108 | doutc(cl, " leaving %p %llx.%llx in newer realm %llx %p\n",
|
| 1109 | inode, ceph_vinop(inode), ci->i_snap_realm->ino,
|
| 1110 | ci->i_snap_realm);
|
| 1111 | goto skip_inode;
|
| 1112 | }
|
| 1113 | doutc(cl, " will move %p %llx.%llx to split realm %llx %p\n",
|
| 1114 | inode, ceph_vinop(inode), realm->ino, realm);
|
| 1115 |
|
| 1116 | ceph_get_snap_realm(mdsc, realm);
|
| 1117 | ceph_change_snap_realm(inode, realm);
|
| 1118 | spin_unlock(&ci->i_ceph_lock);
|
| 1119 | iput(inode);
|
| 1120 | continue;
|
| 1121 |
|
| 1122 | skip_inode:
|
| 1123 | spin_unlock(&ci->i_ceph_lock);
|
| 1124 | iput(inode);
|
| 1125 | }
|
| 1126 |
|
| 1127 |
|
| 1128 | for (i = 0; i < num_split_realms; i++) {
|
| 1129 | struct ceph_snap_realm *child =
|
| 1130 | __lookup_snap_realm(mdsc,
|
| 1131 | le64_to_cpu(split_realms[i]));
|
| 1132 | if (!child)
|
| 1133 | continue;
|
| 1134 | adjust_snap_realm_parent(mdsc, child, realm->ino);
|
| 1135 | }
|
| 1136 | } else {
|
| 1137 | |
| 1138 | * In the non-split case both 'num_split_inos' and
|
| 1139 | * 'num_split_realms' should be 0, making this a no-op.
|
| 1140 | * However the MDS happens to populate 'split_realms' list
|
| 1141 | * in one of the UPDATE op cases by mistake.
|
| 1142 | *
|
| 1143 | * Skip both lists just in case to ensure that 'p' is
|
| 1144 | * positioned at the start of realm info, as expected by
|
| 1145 | * ceph_update_snap_trace().
|
| 1146 |
|
| 1147 | p += sizeof(u64) * num_split_inos;
|
| 1148 | p += sizeof(u64) * num_split_realms;
|
| 1149 | }
|
| 1150 |
|
| 1151 | |
| 1152 | * update using the provided snap trace. if we are deleting a
|
| 1153 | * snap, we can avoid queueing cap_snaps.
|
| 1154 |
|
| 1155 | if (ceph_update_snap_trace(mdsc, p, e,
|
| 1156 | op == CEPH_SNAP_OP_DESTROY,
|
| 1157 | NULL)) {
|
| 1158 | close_sessions = true;
|
| 1159 | goto bad;
|
| 1160 | }
|
| 1161 |
|
| 1162 | if (op == CEPH_SNAP_OP_SPLIT)
|
| 1163 |
|
| 1164 | ceph_put_snap_realm(mdsc, realm);
|
| 1165 |
|
| 1166 | __cleanup_empty_realms(mdsc);
|
| 1167 |
|
| 1168 | up_write(&mdsc->snap_rwsem);
|
| 1169 |
|
| 1170 | flush_snaps(mdsc);
|
| 1171 | ceph_dec_mds_stopping_blocker(mdsc);
|
| 1172 | return;
|
| 1173 |
|
| 1174 | bad:
|
| 1175 | pr_err_client(cl, "corrupt snap message from mds%d\n", mds);
|
| 1176 | ceph_msg_dump(msg);
|
| 1177 | out:
|
| 1178 | if (locked_rwsem)
|
| 1179 | up_write(&mdsc->snap_rwsem);
|
| 1180 |
|
| 1181 | ceph_dec_mds_stopping_blocker(mdsc);
|
| 1182 |
|
| 1183 | if (close_sessions)
|
| 1184 | ceph_mdsc_close_sessions(mdsc);
|
| 1185 | return;
|
| 1186 | }
|
| 1187 |
|
| 1188 | struct ceph_snapid_map* ceph_get_snapid_map(struct ceph_mds_client *mdsc,
|
| 1189 | u64 snap)
|
| 1190 | {
|
| 1191 | struct ceph_client *cl = mdsc->fsc->client;
|
| 1192 | struct ceph_snapid_map *sm, *exist;
|
| 1193 | struct rb_node **p, *parent;
|
| 1194 | int ret;
|
| 1195 |
|
| 1196 | exist = NULL;
|
| 1197 | spin_lock(&mdsc->snapid_map_lock);
|
| 1198 | p = &mdsc->snapid_map_tree.rb_node;
|
| 1199 | while (*p) {
|
| 1200 | exist = rb_entry(*p, struct ceph_snapid_map, node);
|
| 1201 | if (snap > exist->snap) {
|
| 1202 | p = &(*p)->rb_left;
|
| 1203 | } else if (snap < exist->snap) {
|
| 1204 | p = &(*p)->rb_right;
|
| 1205 | } else {
|
| 1206 | if (atomic_inc_return(&exist->ref) == 1)
|
| 1207 | list_del_init(&exist->lru);
|
| 1208 | break;
|
| 1209 | }
|
| 1210 | exist = NULL;
|
| 1211 | }
|
| 1212 | spin_unlock(&mdsc->snapid_map_lock);
|
| 1213 | if (exist) {
|
| 1214 | doutc(cl, "found snapid map %llx -> %x\n", exist->snap,
|
| 1215 | exist->dev);
|
| 1216 | return exist;
|
| 1217 | }
|
| 1218 |
|
| 1219 | sm = kmalloc_obj(*sm, GFP_NOFS);
|
| 1220 | if (!sm)
|
| 1221 | return NULL;
|
| 1222 |
|
| 1223 | ret = get_anon_bdev(&sm->dev);
|
| 1224 | if (ret < 0) {
|
| 1225 | kfree(sm);
|
| 1226 | return NULL;
|
| 1227 | }
|
| 1228 |
|
| 1229 | INIT_LIST_HEAD(&sm->lru);
|
| 1230 | atomic_set(&sm->ref, 1);
|
| 1231 | sm->snap = snap;
|
| 1232 |
|
| 1233 | exist = NULL;
|
| 1234 | parent = NULL;
|
| 1235 | p = &mdsc->snapid_map_tree.rb_node;
|
| 1236 | spin_lock(&mdsc->snapid_map_lock);
|
| 1237 | while (*p) {
|
| 1238 | parent = *p;
|
| 1239 | exist = rb_entry(*p, struct ceph_snapid_map, node);
|
| 1240 | if (snap > exist->snap)
|
| 1241 | p = &(*p)->rb_left;
|
| 1242 | else if (snap < exist->snap)
|
| 1243 | p = &(*p)->rb_right;
|
| 1244 | else
|
| 1245 | break;
|
| 1246 | exist = NULL;
|
| 1247 | }
|
| 1248 | if (exist) {
|
| 1249 | if (atomic_inc_return(&exist->ref) == 1)
|
| 1250 | list_del_init(&exist->lru);
|
| 1251 | } else {
|
| 1252 | rb_link_node(&sm->node, parent, p);
|
| 1253 | rb_insert_color(&sm->node, &mdsc->snapid_map_tree);
|
| 1254 | }
|
| 1255 | spin_unlock(&mdsc->snapid_map_lock);
|
| 1256 | if (exist) {
|
| 1257 | free_anon_bdev(sm->dev);
|
| 1258 | kfree(sm);
|
| 1259 | doutc(cl, "found snapid map %llx -> %x\n", exist->snap,
|
| 1260 | exist->dev);
|
| 1261 | return exist;
|
| 1262 | }
|
| 1263 |
|
| 1264 | doutc(cl, "create snapid map %llx -> %x\n", sm->snap, sm->dev);
|
| 1265 | return sm;
|
| 1266 | }
|
| 1267 |
|
| 1268 | void ceph_put_snapid_map(struct ceph_mds_client* mdsc,
|
| 1269 | struct ceph_snapid_map *sm)
|
| 1270 | {
|
| 1271 | if (!sm)
|
| 1272 | return;
|
| 1273 | if (atomic_dec_and_lock(&sm->ref, &mdsc->snapid_map_lock)) {
|
| 1274 | if (!RB_EMPTY_NODE(&sm->node)) {
|
| 1275 | sm->last_used = jiffies;
|
| 1276 | list_add_tail(&sm->lru, &mdsc->snapid_map_lru);
|
| 1277 | spin_unlock(&mdsc->snapid_map_lock);
|
| 1278 | } else {
|
| 1279 | |
| 1280 | * ceph_cleanup_snapid_map()
|
| 1281 | spin_unlock(&mdsc->snapid_map_lock);
|
| 1282 | kfree(sm);
|
| 1283 | }
|
| 1284 | }
|
| 1285 | }
|
| 1286 |
|
| 1287 | void ceph_trim_snapid_map(struct ceph_mds_client *mdsc)
|
| 1288 | {
|
| 1289 | struct ceph_client *cl = mdsc->fsc->client;
|
| 1290 | struct ceph_snapid_map *sm;
|
| 1291 | unsigned long now;
|
| 1292 | LIST_HEAD(to_free);
|
| 1293 |
|
| 1294 | spin_lock(&mdsc->snapid_map_lock);
|
| 1295 | now = jiffies;
|
| 1296 |
|
| 1297 | while (!list_empty(&mdsc->snapid_map_lru)) {
|
| 1298 | sm = list_first_entry(&mdsc->snapid_map_lru,
|
| 1299 | struct ceph_snapid_map, lru);
|
| 1300 | if (time_after(sm->last_used + CEPH_SNAPID_MAP_TIMEOUT, now))
|
| 1301 | break;
|
| 1302 |
|
| 1303 | rb_erase(&sm->node, &mdsc->snapid_map_tree);
|
| 1304 | list_move(&sm->lru, &to_free);
|
| 1305 | }
|
| 1306 | spin_unlock(&mdsc->snapid_map_lock);
|
| 1307 |
|
| 1308 | while (!list_empty(&to_free)) {
|
| 1309 | sm = list_first_entry(&to_free, struct ceph_snapid_map, lru);
|
| 1310 | list_del(&sm->lru);
|
| 1311 | doutc(cl, "trim snapid map %llx -> %x\n", sm->snap, sm->dev);
|
| 1312 | free_anon_bdev(sm->dev);
|
| 1313 | kfree(sm);
|
| 1314 | }
|
| 1315 | }
|
| 1316 |
|
| 1317 | void ceph_cleanup_snapid_map(struct ceph_mds_client *mdsc)
|
| 1318 | {
|
| 1319 | struct ceph_client *cl = mdsc->fsc->client;
|
| 1320 | struct ceph_snapid_map *sm;
|
| 1321 | struct rb_node *p;
|
| 1322 | LIST_HEAD(to_free);
|
| 1323 |
|
| 1324 | spin_lock(&mdsc->snapid_map_lock);
|
| 1325 | while ((p = rb_first(&mdsc->snapid_map_tree))) {
|
| 1326 | sm = rb_entry(p, struct ceph_snapid_map, node);
|
| 1327 | rb_erase(p, &mdsc->snapid_map_tree);
|
| 1328 | RB_CLEAR_NODE(p);
|
| 1329 | list_move(&sm->lru, &to_free);
|
| 1330 | }
|
| 1331 | spin_unlock(&mdsc->snapid_map_lock);
|
| 1332 |
|
| 1333 | while (!list_empty(&to_free)) {
|
| 1334 | sm = list_first_entry(&to_free, struct ceph_snapid_map, lru);
|
| 1335 | list_del(&sm->lru);
|
| 1336 | free_anon_bdev(sm->dev);
|
| 1337 | if (WARN_ON_ONCE(atomic_read(&sm->ref))) {
|
| 1338 | pr_err_client(cl, "snapid map %llx -> %x still in use\n",
|
| 1339 | sm->snap, sm->dev);
|
| 1340 | }
|
| 1341 | kfree(sm);
|
| 1342 | }
|
| 1343 | }
|