| 1 | /* |
| 2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| 4 | * |
| 5 | * This copyrighted material is made available to anyone wishing to use, |
| 6 | * modify, copy, or redistribute it subject to the terms and conditions |
| 7 | * of the GNU General Public License version 2. |
| 8 | */ |
| 9 | |
| 10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 11 | |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/spinlock.h> |
| 15 | #include <linux/buffer_head.h> |
| 16 | #include <linux/delay.h> |
| 17 | #include <linux/sort.h> |
| 18 | #include <linux/jhash.h> |
| 19 | #include <linux/kallsyms.h> |
| 20 | #include <linux/gfs2_ondisk.h> |
| 21 | #include <linux/list.h> |
| 22 | #include <linux/wait.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <asm/uaccess.h> |
| 25 | #include <linux/seq_file.h> |
| 26 | #include <linux/debugfs.h> |
| 27 | #include <linux/kthread.h> |
| 28 | #include <linux/freezer.h> |
| 29 | #include <linux/workqueue.h> |
| 30 | #include <linux/jiffies.h> |
| 31 | #include <linux/rcupdate.h> |
| 32 | #include <linux/rculist_bl.h> |
| 33 | #include <linux/bit_spinlock.h> |
| 34 | #include <linux/percpu.h> |
| 35 | #include <linux/list_sort.h> |
| 36 | #include <linux/lockref.h> |
| 37 | #include <linux/rhashtable.h> |
| 38 | |
| 39 | #include "gfs2.h" |
| 40 | #include "incore.h" |
| 41 | #include "glock.h" |
| 42 | #include "glops.h" |
| 43 | #include "inode.h" |
| 44 | #include "lops.h" |
| 45 | #include "meta_io.h" |
| 46 | #include "quota.h" |
| 47 | #include "super.h" |
| 48 | #include "util.h" |
| 49 | #include "bmap.h" |
| 50 | #define CREATE_TRACE_POINTS |
| 51 | #include "trace_gfs2.h" |
| 52 | |
| 53 | struct gfs2_glock_iter { |
| 54 | struct gfs2_sbd *sdp; /* incore superblock */ |
| 55 | struct rhashtable_iter hti; /* rhashtable iterator */ |
| 56 | struct gfs2_glock *gl; /* current glock struct */ |
| 57 | loff_t last_pos; /* last position */ |
| 58 | }; |
| 59 | |
| 60 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
| 61 | |
| 62 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); |
| 63 | |
| 64 | static struct dentry *gfs2_root; |
| 65 | static struct workqueue_struct *glock_workqueue; |
| 66 | struct workqueue_struct *gfs2_delete_workqueue; |
| 67 | static LIST_HEAD(lru_list); |
| 68 | static atomic_t lru_count = ATOMIC_INIT(0); |
| 69 | static DEFINE_SPINLOCK(lru_lock); |
| 70 | |
| 71 | #define GFS2_GL_HASH_SHIFT 15 |
| 72 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
| 73 | |
| 74 | static struct rhashtable_params ht_parms = { |
| 75 | .nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4, |
| 76 | .key_len = sizeof(struct lm_lockname), |
| 77 | .key_offset = offsetof(struct gfs2_glock, gl_name), |
| 78 | .head_offset = offsetof(struct gfs2_glock, gl_node), |
| 79 | }; |
| 80 | |
| 81 | static struct rhashtable gl_hash_table; |
| 82 | |
| 83 | void gfs2_glock_free(struct gfs2_glock *gl) |
| 84 | { |
| 85 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| 86 | |
| 87 | if (gl->gl_ops->go_flags & GLOF_ASPACE) { |
| 88 | kmem_cache_free(gfs2_glock_aspace_cachep, gl); |
| 89 | } else { |
| 90 | kfree(gl->gl_lksb.sb_lvbptr); |
| 91 | kmem_cache_free(gfs2_glock_cachep, gl); |
| 92 | } |
| 93 | if (atomic_dec_and_test(&sdp->sd_glock_disposal)) |
| 94 | wake_up(&sdp->sd_glock_wait); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * gfs2_glock_hold() - increment reference count on glock |
| 99 | * @gl: The glock to hold |
| 100 | * |
| 101 | */ |
| 102 | |
| 103 | static void gfs2_glock_hold(struct gfs2_glock *gl) |
| 104 | { |
| 105 | GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref)); |
| 106 | lockref_get(&gl->gl_lockref); |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * demote_ok - Check to see if it's ok to unlock a glock |
| 111 | * @gl: the glock |
| 112 | * |
| 113 | * Returns: 1 if it's ok |
| 114 | */ |
| 115 | |
| 116 | static int demote_ok(const struct gfs2_glock *gl) |
| 117 | { |
| 118 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
| 119 | |
| 120 | if (gl->gl_state == LM_ST_UNLOCKED) |
| 121 | return 0; |
| 122 | if (!list_empty(&gl->gl_holders)) |
| 123 | return 0; |
| 124 | if (glops->go_demote_ok) |
| 125 | return glops->go_demote_ok(gl); |
| 126 | return 1; |
| 127 | } |
| 128 | |
| 129 | |
| 130 | void gfs2_glock_add_to_lru(struct gfs2_glock *gl) |
| 131 | { |
| 132 | spin_lock(&lru_lock); |
| 133 | |
| 134 | if (!list_empty(&gl->gl_lru)) |
| 135 | list_del_init(&gl->gl_lru); |
| 136 | else |
| 137 | atomic_inc(&lru_count); |
| 138 | |
| 139 | list_add_tail(&gl->gl_lru, &lru_list); |
| 140 | set_bit(GLF_LRU, &gl->gl_flags); |
| 141 | spin_unlock(&lru_lock); |
| 142 | } |
| 143 | |
| 144 | static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) |
| 145 | { |
| 146 | spin_lock(&lru_lock); |
| 147 | if (!list_empty(&gl->gl_lru)) { |
| 148 | list_del_init(&gl->gl_lru); |
| 149 | atomic_dec(&lru_count); |
| 150 | clear_bit(GLF_LRU, &gl->gl_flags); |
| 151 | } |
| 152 | spin_unlock(&lru_lock); |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | * gfs2_glock_put() - Decrement reference count on glock |
| 157 | * @gl: The glock to put |
| 158 | * |
| 159 | */ |
| 160 | |
| 161 | void gfs2_glock_put(struct gfs2_glock *gl) |
| 162 | { |
| 163 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| 164 | struct address_space *mapping = gfs2_glock2aspace(gl); |
| 165 | |
| 166 | if (lockref_put_or_lock(&gl->gl_lockref)) |
| 167 | return; |
| 168 | |
| 169 | lockref_mark_dead(&gl->gl_lockref); |
| 170 | |
| 171 | gfs2_glock_remove_from_lru(gl); |
| 172 | spin_unlock(&gl->gl_lockref.lock); |
| 173 | rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms); |
| 174 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
| 175 | GLOCK_BUG_ON(gl, mapping && mapping->nrpages); |
| 176 | trace_gfs2_glock_put(gl); |
| 177 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * may_grant - check if its ok to grant a new lock |
| 182 | * @gl: The glock |
| 183 | * @gh: The lock request which we wish to grant |
| 184 | * |
| 185 | * Returns: true if its ok to grant the lock |
| 186 | */ |
| 187 | |
| 188 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) |
| 189 | { |
| 190 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); |
| 191 | if ((gh->gh_state == LM_ST_EXCLUSIVE || |
| 192 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) |
| 193 | return 0; |
| 194 | if (gl->gl_state == gh->gh_state) |
| 195 | return 1; |
| 196 | if (gh->gh_flags & GL_EXACT) |
| 197 | return 0; |
| 198 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
| 199 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) |
| 200 | return 1; |
| 201 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) |
| 202 | return 1; |
| 203 | } |
| 204 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
| 205 | return 1; |
| 206 | return 0; |
| 207 | } |
| 208 | |
| 209 | static void gfs2_holder_wake(struct gfs2_holder *gh) |
| 210 | { |
| 211 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
| 212 | smp_mb__after_atomic(); |
| 213 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * do_error - Something unexpected has happened during a lock request |
| 218 | * |
| 219 | */ |
| 220 | |
| 221 | static void do_error(struct gfs2_glock *gl, const int ret) |
| 222 | { |
| 223 | struct gfs2_holder *gh, *tmp; |
| 224 | |
| 225 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { |
| 226 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| 227 | continue; |
| 228 | if (ret & LM_OUT_ERROR) |
| 229 | gh->gh_error = -EIO; |
| 230 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
| 231 | gh->gh_error = GLR_TRYFAILED; |
| 232 | else |
| 233 | continue; |
| 234 | list_del_init(&gh->gh_list); |
| 235 | trace_gfs2_glock_queue(gh, 0); |
| 236 | gfs2_holder_wake(gh); |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * do_promote - promote as many requests as possible on the current queue |
| 242 | * @gl: The glock |
| 243 | * |
| 244 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
| 245 | * if a type specific operation is underway. |
| 246 | */ |
| 247 | |
| 248 | static int do_promote(struct gfs2_glock *gl) |
| 249 | __releases(&gl->gl_lockref.lock) |
| 250 | __acquires(&gl->gl_lockref.lock) |
| 251 | { |
| 252 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
| 253 | struct gfs2_holder *gh, *tmp; |
| 254 | int ret; |
| 255 | |
| 256 | restart: |
| 257 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { |
| 258 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| 259 | continue; |
| 260 | if (may_grant(gl, gh)) { |
| 261 | if (gh->gh_list.prev == &gl->gl_holders && |
| 262 | glops->go_lock) { |
| 263 | spin_unlock(&gl->gl_lockref.lock); |
| 264 | /* FIXME: eliminate this eventually */ |
| 265 | ret = glops->go_lock(gh); |
| 266 | spin_lock(&gl->gl_lockref.lock); |
| 267 | if (ret) { |
| 268 | if (ret == 1) |
| 269 | return 2; |
| 270 | gh->gh_error = ret; |
| 271 | list_del_init(&gh->gh_list); |
| 272 | trace_gfs2_glock_queue(gh, 0); |
| 273 | gfs2_holder_wake(gh); |
| 274 | goto restart; |
| 275 | } |
| 276 | set_bit(HIF_HOLDER, &gh->gh_iflags); |
| 277 | trace_gfs2_promote(gh, 1); |
| 278 | gfs2_holder_wake(gh); |
| 279 | goto restart; |
| 280 | } |
| 281 | set_bit(HIF_HOLDER, &gh->gh_iflags); |
| 282 | trace_gfs2_promote(gh, 0); |
| 283 | gfs2_holder_wake(gh); |
| 284 | continue; |
| 285 | } |
| 286 | if (gh->gh_list.prev == &gl->gl_holders) |
| 287 | return 1; |
| 288 | do_error(gl, 0); |
| 289 | break; |
| 290 | } |
| 291 | return 0; |
| 292 | } |
| 293 | |
| 294 | /** |
| 295 | * find_first_waiter - find the first gh that's waiting for the glock |
| 296 | * @gl: the glock |
| 297 | */ |
| 298 | |
| 299 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) |
| 300 | { |
| 301 | struct gfs2_holder *gh; |
| 302 | |
| 303 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| 304 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| 305 | return gh; |
| 306 | } |
| 307 | return NULL; |
| 308 | } |
| 309 | |
| 310 | /** |
| 311 | * state_change - record that the glock is now in a different state |
| 312 | * @gl: the glock |
| 313 | * @new_state the new state |
| 314 | * |
| 315 | */ |
| 316 | |
| 317 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) |
| 318 | { |
| 319 | int held1, held2; |
| 320 | |
| 321 | held1 = (gl->gl_state != LM_ST_UNLOCKED); |
| 322 | held2 = (new_state != LM_ST_UNLOCKED); |
| 323 | |
| 324 | if (held1 != held2) { |
| 325 | GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref)); |
| 326 | if (held2) |
| 327 | gl->gl_lockref.count++; |
| 328 | else |
| 329 | gl->gl_lockref.count--; |
| 330 | } |
| 331 | if (held1 && held2 && list_empty(&gl->gl_holders)) |
| 332 | clear_bit(GLF_QUEUED, &gl->gl_flags); |
| 333 | |
| 334 | if (new_state != gl->gl_target) |
| 335 | /* shorten our minimum hold time */ |
| 336 | gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR, |
| 337 | GL_GLOCK_MIN_HOLD); |
| 338 | gl->gl_state = new_state; |
| 339 | gl->gl_tchange = jiffies; |
| 340 | } |
| 341 | |
| 342 | static void gfs2_demote_wake(struct gfs2_glock *gl) |
| 343 | { |
| 344 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
| 345 | clear_bit(GLF_DEMOTE, &gl->gl_flags); |
| 346 | smp_mb__after_atomic(); |
| 347 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); |
| 348 | } |
| 349 | |
| 350 | /** |
| 351 | * finish_xmote - The DLM has replied to one of our lock requests |
| 352 | * @gl: The glock |
| 353 | * @ret: The status from the DLM |
| 354 | * |
| 355 | */ |
| 356 | |
| 357 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) |
| 358 | { |
| 359 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
| 360 | struct gfs2_holder *gh; |
| 361 | unsigned state = ret & LM_OUT_ST_MASK; |
| 362 | int rv; |
| 363 | |
| 364 | spin_lock(&gl->gl_lockref.lock); |
| 365 | trace_gfs2_glock_state_change(gl, state); |
| 366 | state_change(gl, state); |
| 367 | gh = find_first_waiter(gl); |
| 368 | |
| 369 | /* Demote to UN request arrived during demote to SH or DF */ |
| 370 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && |
| 371 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) |
| 372 | gl->gl_target = LM_ST_UNLOCKED; |
| 373 | |
| 374 | /* Check for state != intended state */ |
| 375 | if (unlikely(state != gl->gl_target)) { |
| 376 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { |
| 377 | /* move to back of queue and try next entry */ |
| 378 | if (ret & LM_OUT_CANCELED) { |
| 379 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) |
| 380 | list_move_tail(&gh->gh_list, &gl->gl_holders); |
| 381 | gh = find_first_waiter(gl); |
| 382 | gl->gl_target = gh->gh_state; |
| 383 | goto retry; |
| 384 | } |
| 385 | /* Some error or failed "try lock" - report it */ |
| 386 | if ((ret & LM_OUT_ERROR) || |
| 387 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { |
| 388 | gl->gl_target = gl->gl_state; |
| 389 | do_error(gl, ret); |
| 390 | goto out; |
| 391 | } |
| 392 | } |
| 393 | switch(state) { |
| 394 | /* Unlocked due to conversion deadlock, try again */ |
| 395 | case LM_ST_UNLOCKED: |
| 396 | retry: |
| 397 | do_xmote(gl, gh, gl->gl_target); |
| 398 | break; |
| 399 | /* Conversion fails, unlock and try again */ |
| 400 | case LM_ST_SHARED: |
| 401 | case LM_ST_DEFERRED: |
| 402 | do_xmote(gl, gh, LM_ST_UNLOCKED); |
| 403 | break; |
| 404 | default: /* Everything else */ |
| 405 | pr_err("wanted %u got %u\n", gl->gl_target, state); |
| 406 | GLOCK_BUG_ON(gl, 1); |
| 407 | } |
| 408 | spin_unlock(&gl->gl_lockref.lock); |
| 409 | return; |
| 410 | } |
| 411 | |
| 412 | /* Fast path - we got what we asked for */ |
| 413 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) |
| 414 | gfs2_demote_wake(gl); |
| 415 | if (state != LM_ST_UNLOCKED) { |
| 416 | if (glops->go_xmote_bh) { |
| 417 | spin_unlock(&gl->gl_lockref.lock); |
| 418 | rv = glops->go_xmote_bh(gl, gh); |
| 419 | spin_lock(&gl->gl_lockref.lock); |
| 420 | if (rv) { |
| 421 | do_error(gl, rv); |
| 422 | goto out; |
| 423 | } |
| 424 | } |
| 425 | rv = do_promote(gl); |
| 426 | if (rv == 2) |
| 427 | goto out_locked; |
| 428 | } |
| 429 | out: |
| 430 | clear_bit(GLF_LOCK, &gl->gl_flags); |
| 431 | out_locked: |
| 432 | spin_unlock(&gl->gl_lockref.lock); |
| 433 | } |
| 434 | |
| 435 | /** |
| 436 | * do_xmote - Calls the DLM to change the state of a lock |
| 437 | * @gl: The lock state |
| 438 | * @gh: The holder (only for promotes) |
| 439 | * @target: The target lock state |
| 440 | * |
| 441 | */ |
| 442 | |
| 443 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) |
| 444 | __releases(&gl->gl_lockref.lock) |
| 445 | __acquires(&gl->gl_lockref.lock) |
| 446 | { |
| 447 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
| 448 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| 449 | unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0); |
| 450 | int ret; |
| 451 | |
| 452 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | |
| 453 | LM_FLAG_PRIORITY); |
| 454 | GLOCK_BUG_ON(gl, gl->gl_state == target); |
| 455 | GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target); |
| 456 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && |
| 457 | glops->go_inval) { |
| 458 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); |
| 459 | do_error(gl, 0); /* Fail queued try locks */ |
| 460 | } |
| 461 | gl->gl_req = target; |
| 462 | set_bit(GLF_BLOCKING, &gl->gl_flags); |
| 463 | if ((gl->gl_req == LM_ST_UNLOCKED) || |
| 464 | (gl->gl_state == LM_ST_EXCLUSIVE) || |
| 465 | (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB))) |
| 466 | clear_bit(GLF_BLOCKING, &gl->gl_flags); |
| 467 | spin_unlock(&gl->gl_lockref.lock); |
| 468 | if (glops->go_sync) |
| 469 | glops->go_sync(gl); |
| 470 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) |
| 471 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); |
| 472 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); |
| 473 | |
| 474 | gfs2_glock_hold(gl); |
| 475 | if (sdp->sd_lockstruct.ls_ops->lm_lock) { |
| 476 | /* lock_dlm */ |
| 477 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags); |
| 478 | if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED && |
| 479 | target == LM_ST_UNLOCKED && |
| 480 | test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) { |
| 481 | finish_xmote(gl, target); |
| 482 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 483 | gfs2_glock_put(gl); |
| 484 | } |
| 485 | else if (ret) { |
| 486 | pr_err("lm_lock ret %d\n", ret); |
| 487 | GLOCK_BUG_ON(gl, 1); |
| 488 | } |
| 489 | } else { /* lock_nolock */ |
| 490 | finish_xmote(gl, target); |
| 491 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 492 | gfs2_glock_put(gl); |
| 493 | } |
| 494 | |
| 495 | spin_lock(&gl->gl_lockref.lock); |
| 496 | } |
| 497 | |
| 498 | /** |
| 499 | * find_first_holder - find the first "holder" gh |
| 500 | * @gl: the glock |
| 501 | */ |
| 502 | |
| 503 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) |
| 504 | { |
| 505 | struct gfs2_holder *gh; |
| 506 | |
| 507 | if (!list_empty(&gl->gl_holders)) { |
| 508 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); |
| 509 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| 510 | return gh; |
| 511 | } |
| 512 | return NULL; |
| 513 | } |
| 514 | |
| 515 | /** |
| 516 | * run_queue - do all outstanding tasks related to a glock |
| 517 | * @gl: The glock in question |
| 518 | * @nonblock: True if we must not block in run_queue |
| 519 | * |
| 520 | */ |
| 521 | |
| 522 | static void run_queue(struct gfs2_glock *gl, const int nonblock) |
| 523 | __releases(&gl->gl_lockref.lock) |
| 524 | __acquires(&gl->gl_lockref.lock) |
| 525 | { |
| 526 | struct gfs2_holder *gh = NULL; |
| 527 | int ret; |
| 528 | |
| 529 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) |
| 530 | return; |
| 531 | |
| 532 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); |
| 533 | |
| 534 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && |
| 535 | gl->gl_demote_state != gl->gl_state) { |
| 536 | if (find_first_holder(gl)) |
| 537 | goto out_unlock; |
| 538 | if (nonblock) |
| 539 | goto out_sched; |
| 540 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); |
| 541 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
| 542 | gl->gl_target = gl->gl_demote_state; |
| 543 | } else { |
| 544 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| 545 | gfs2_demote_wake(gl); |
| 546 | ret = do_promote(gl); |
| 547 | if (ret == 0) |
| 548 | goto out_unlock; |
| 549 | if (ret == 2) |
| 550 | goto out; |
| 551 | gh = find_first_waiter(gl); |
| 552 | gl->gl_target = gh->gh_state; |
| 553 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) |
| 554 | do_error(gl, 0); /* Fail queued try locks */ |
| 555 | } |
| 556 | do_xmote(gl, gh, gl->gl_target); |
| 557 | out: |
| 558 | return; |
| 559 | |
| 560 | out_sched: |
| 561 | clear_bit(GLF_LOCK, &gl->gl_flags); |
| 562 | smp_mb__after_atomic(); |
| 563 | gl->gl_lockref.count++; |
| 564 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 565 | gl->gl_lockref.count--; |
| 566 | return; |
| 567 | |
| 568 | out_unlock: |
| 569 | clear_bit(GLF_LOCK, &gl->gl_flags); |
| 570 | smp_mb__after_atomic(); |
| 571 | return; |
| 572 | } |
| 573 | |
| 574 | static void delete_work_func(struct work_struct *work) |
| 575 | { |
| 576 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); |
| 577 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| 578 | struct gfs2_inode *ip; |
| 579 | struct inode *inode; |
| 580 | u64 no_addr = gl->gl_name.ln_number; |
| 581 | |
| 582 | /* If someone's using this glock to create a new dinode, the block must |
| 583 | have been freed by another node, then re-used, in which case our |
| 584 | iopen callback is too late after the fact. Ignore it. */ |
| 585 | if (test_bit(GLF_INODE_CREATING, &gl->gl_flags)) |
| 586 | goto out; |
| 587 | |
| 588 | ip = gl->gl_object; |
| 589 | /* Note: Unsafe to dereference ip as we don't hold right refs/locks */ |
| 590 | |
| 591 | if (ip) |
| 592 | inode = gfs2_ilookup(sdp->sd_vfs, no_addr); |
| 593 | else |
| 594 | inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED); |
| 595 | if (inode && !IS_ERR(inode)) { |
| 596 | d_prune_aliases(inode); |
| 597 | iput(inode); |
| 598 | } |
| 599 | out: |
| 600 | gfs2_glock_put(gl); |
| 601 | } |
| 602 | |
| 603 | static void glock_work_func(struct work_struct *work) |
| 604 | { |
| 605 | unsigned long delay = 0; |
| 606 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
| 607 | int drop_ref = 0; |
| 608 | |
| 609 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
| 610 | finish_xmote(gl, gl->gl_reply); |
| 611 | drop_ref = 1; |
| 612 | } |
| 613 | spin_lock(&gl->gl_lockref.lock); |
| 614 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| 615 | gl->gl_state != LM_ST_UNLOCKED && |
| 616 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { |
| 617 | unsigned long holdtime, now = jiffies; |
| 618 | |
| 619 | holdtime = gl->gl_tchange + gl->gl_hold_time; |
| 620 | if (time_before(now, holdtime)) |
| 621 | delay = holdtime - now; |
| 622 | |
| 623 | if (!delay) { |
| 624 | clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags); |
| 625 | set_bit(GLF_DEMOTE, &gl->gl_flags); |
| 626 | } |
| 627 | } |
| 628 | run_queue(gl, 0); |
| 629 | spin_unlock(&gl->gl_lockref.lock); |
| 630 | if (!delay) |
| 631 | gfs2_glock_put(gl); |
| 632 | else { |
| 633 | if (gl->gl_name.ln_type != LM_TYPE_INODE) |
| 634 | delay = 0; |
| 635 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
| 636 | gfs2_glock_put(gl); |
| 637 | } |
| 638 | if (drop_ref) |
| 639 | gfs2_glock_put(gl); |
| 640 | } |
| 641 | |
| 642 | /** |
| 643 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist |
| 644 | * @sdp: The GFS2 superblock |
| 645 | * @number: the lock number |
| 646 | * @glops: The glock_operations to use |
| 647 | * @create: If 0, don't create the glock if it doesn't exist |
| 648 | * @glp: the glock is returned here |
| 649 | * |
| 650 | * This does not lock a glock, just finds/creates structures for one. |
| 651 | * |
| 652 | * Returns: errno |
| 653 | */ |
| 654 | |
| 655 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
| 656 | const struct gfs2_glock_operations *glops, int create, |
| 657 | struct gfs2_glock **glp) |
| 658 | { |
| 659 | struct super_block *s = sdp->sd_vfs; |
| 660 | struct lm_lockname name = { .ln_number = number, |
| 661 | .ln_type = glops->go_type, |
| 662 | .ln_sbd = sdp }; |
| 663 | struct gfs2_glock *gl, *tmp = NULL; |
| 664 | struct address_space *mapping; |
| 665 | struct kmem_cache *cachep; |
| 666 | int ret, tries = 0; |
| 667 | |
| 668 | gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms); |
| 669 | if (gl && !lockref_get_not_dead(&gl->gl_lockref)) |
| 670 | gl = NULL; |
| 671 | |
| 672 | *glp = gl; |
| 673 | if (gl) |
| 674 | return 0; |
| 675 | if (!create) |
| 676 | return -ENOENT; |
| 677 | |
| 678 | if (glops->go_flags & GLOF_ASPACE) |
| 679 | cachep = gfs2_glock_aspace_cachep; |
| 680 | else |
| 681 | cachep = gfs2_glock_cachep; |
| 682 | gl = kmem_cache_alloc(cachep, GFP_NOFS); |
| 683 | if (!gl) |
| 684 | return -ENOMEM; |
| 685 | |
| 686 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); |
| 687 | |
| 688 | if (glops->go_flags & GLOF_LVB) { |
| 689 | gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_NOFS); |
| 690 | if (!gl->gl_lksb.sb_lvbptr) { |
| 691 | kmem_cache_free(cachep, gl); |
| 692 | return -ENOMEM; |
| 693 | } |
| 694 | } |
| 695 | |
| 696 | atomic_inc(&sdp->sd_glock_disposal); |
| 697 | gl->gl_node.next = NULL; |
| 698 | gl->gl_flags = 0; |
| 699 | gl->gl_name = name; |
| 700 | gl->gl_lockref.count = 1; |
| 701 | gl->gl_state = LM_ST_UNLOCKED; |
| 702 | gl->gl_target = LM_ST_UNLOCKED; |
| 703 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
| 704 | gl->gl_ops = glops; |
| 705 | gl->gl_dstamp = ktime_set(0, 0); |
| 706 | preempt_disable(); |
| 707 | /* We use the global stats to estimate the initial per-glock stats */ |
| 708 | gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type]; |
| 709 | preempt_enable(); |
| 710 | gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0; |
| 711 | gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0; |
| 712 | gl->gl_tchange = jiffies; |
| 713 | gl->gl_object = NULL; |
| 714 | gl->gl_hold_time = GL_GLOCK_DFT_HOLD; |
| 715 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
| 716 | INIT_WORK(&gl->gl_delete, delete_work_func); |
| 717 | |
| 718 | mapping = gfs2_glock2aspace(gl); |
| 719 | if (mapping) { |
| 720 | mapping->a_ops = &gfs2_meta_aops; |
| 721 | mapping->host = s->s_bdev->bd_inode; |
| 722 | mapping->flags = 0; |
| 723 | mapping_set_gfp_mask(mapping, GFP_NOFS); |
| 724 | mapping->private_data = NULL; |
| 725 | mapping->writeback_index = 0; |
| 726 | } |
| 727 | |
| 728 | again: |
| 729 | ret = rhashtable_lookup_insert_fast(&gl_hash_table, &gl->gl_node, |
| 730 | ht_parms); |
| 731 | if (ret == 0) { |
| 732 | *glp = gl; |
| 733 | return 0; |
| 734 | } |
| 735 | |
| 736 | if (ret == -EEXIST) { |
| 737 | ret = 0; |
| 738 | tmp = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms); |
| 739 | if (tmp == NULL || !lockref_get_not_dead(&tmp->gl_lockref)) { |
| 740 | if (++tries < 100) { |
| 741 | cond_resched(); |
| 742 | goto again; |
| 743 | } |
| 744 | tmp = NULL; |
| 745 | ret = -ENOMEM; |
| 746 | } |
| 747 | } else { |
| 748 | WARN_ON_ONCE(ret); |
| 749 | } |
| 750 | kfree(gl->gl_lksb.sb_lvbptr); |
| 751 | kmem_cache_free(cachep, gl); |
| 752 | atomic_dec(&sdp->sd_glock_disposal); |
| 753 | *glp = tmp; |
| 754 | |
| 755 | return ret; |
| 756 | } |
| 757 | |
| 758 | /** |
| 759 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way |
| 760 | * @gl: the glock |
| 761 | * @state: the state we're requesting |
| 762 | * @flags: the modifier flags |
| 763 | * @gh: the holder structure |
| 764 | * |
| 765 | */ |
| 766 | |
| 767 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags, |
| 768 | struct gfs2_holder *gh) |
| 769 | { |
| 770 | INIT_LIST_HEAD(&gh->gh_list); |
| 771 | gh->gh_gl = gl; |
| 772 | gh->gh_ip = _RET_IP_; |
| 773 | gh->gh_owner_pid = get_pid(task_pid(current)); |
| 774 | gh->gh_state = state; |
| 775 | gh->gh_flags = flags; |
| 776 | gh->gh_error = 0; |
| 777 | gh->gh_iflags = 0; |
| 778 | gfs2_glock_hold(gl); |
| 779 | } |
| 780 | |
| 781 | /** |
| 782 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it |
| 783 | * @state: the state we're requesting |
| 784 | * @flags: the modifier flags |
| 785 | * @gh: the holder structure |
| 786 | * |
| 787 | * Don't mess with the glock. |
| 788 | * |
| 789 | */ |
| 790 | |
| 791 | void gfs2_holder_reinit(unsigned int state, u16 flags, struct gfs2_holder *gh) |
| 792 | { |
| 793 | gh->gh_state = state; |
| 794 | gh->gh_flags = flags; |
| 795 | gh->gh_iflags = 0; |
| 796 | gh->gh_ip = _RET_IP_; |
| 797 | put_pid(gh->gh_owner_pid); |
| 798 | gh->gh_owner_pid = get_pid(task_pid(current)); |
| 799 | } |
| 800 | |
| 801 | /** |
| 802 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) |
| 803 | * @gh: the holder structure |
| 804 | * |
| 805 | */ |
| 806 | |
| 807 | void gfs2_holder_uninit(struct gfs2_holder *gh) |
| 808 | { |
| 809 | put_pid(gh->gh_owner_pid); |
| 810 | gfs2_glock_put(gh->gh_gl); |
| 811 | gh->gh_gl = NULL; |
| 812 | gh->gh_ip = 0; |
| 813 | } |
| 814 | |
| 815 | /** |
| 816 | * gfs2_glock_wait - wait on a glock acquisition |
| 817 | * @gh: the glock holder |
| 818 | * |
| 819 | * Returns: 0 on success |
| 820 | */ |
| 821 | |
| 822 | int gfs2_glock_wait(struct gfs2_holder *gh) |
| 823 | { |
| 824 | unsigned long time1 = jiffies; |
| 825 | |
| 826 | might_sleep(); |
| 827 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE); |
| 828 | if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */ |
| 829 | /* Lengthen the minimum hold time. */ |
| 830 | gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time + |
| 831 | GL_GLOCK_HOLD_INCR, |
| 832 | GL_GLOCK_MAX_HOLD); |
| 833 | return gh->gh_error; |
| 834 | } |
| 835 | |
| 836 | /** |
| 837 | * handle_callback - process a demote request |
| 838 | * @gl: the glock |
| 839 | * @state: the state the caller wants us to change to |
| 840 | * |
| 841 | * There are only two requests that we are going to see in actual |
| 842 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED |
| 843 | */ |
| 844 | |
| 845 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
| 846 | unsigned long delay, bool remote) |
| 847 | { |
| 848 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
| 849 | |
| 850 | set_bit(bit, &gl->gl_flags); |
| 851 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { |
| 852 | gl->gl_demote_state = state; |
| 853 | gl->gl_demote_time = jiffies; |
| 854 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
| 855 | gl->gl_demote_state != state) { |
| 856 | gl->gl_demote_state = LM_ST_UNLOCKED; |
| 857 | } |
| 858 | if (gl->gl_ops->go_callback) |
| 859 | gl->gl_ops->go_callback(gl, remote); |
| 860 | trace_gfs2_demote_rq(gl, remote); |
| 861 | } |
| 862 | |
| 863 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
| 864 | { |
| 865 | struct va_format vaf; |
| 866 | va_list args; |
| 867 | |
| 868 | va_start(args, fmt); |
| 869 | |
| 870 | if (seq) { |
| 871 | seq_vprintf(seq, fmt, args); |
| 872 | } else { |
| 873 | vaf.fmt = fmt; |
| 874 | vaf.va = &args; |
| 875 | |
| 876 | pr_err("%pV", &vaf); |
| 877 | } |
| 878 | |
| 879 | va_end(args); |
| 880 | } |
| 881 | |
| 882 | /** |
| 883 | * add_to_queue - Add a holder to the wait queue (but look for recursion) |
| 884 | * @gh: the holder structure to add |
| 885 | * |
| 886 | * Eventually we should move the recursive locking trap to a |
| 887 | * debugging option or something like that. This is the fast |
| 888 | * path and needs to have the minimum number of distractions. |
| 889 | * |
| 890 | */ |
| 891 | |
| 892 | static inline void add_to_queue(struct gfs2_holder *gh) |
| 893 | __releases(&gl->gl_lockref.lock) |
| 894 | __acquires(&gl->gl_lockref.lock) |
| 895 | { |
| 896 | struct gfs2_glock *gl = gh->gh_gl; |
| 897 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| 898 | struct list_head *insert_pt = NULL; |
| 899 | struct gfs2_holder *gh2; |
| 900 | int try_futile = 0; |
| 901 | |
| 902 | BUG_ON(gh->gh_owner_pid == NULL); |
| 903 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
| 904 | BUG(); |
| 905 | |
| 906 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
| 907 | if (test_bit(GLF_LOCK, &gl->gl_flags)) |
| 908 | try_futile = !may_grant(gl, gh); |
| 909 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) |
| 910 | goto fail; |
| 911 | } |
| 912 | |
| 913 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { |
| 914 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && |
| 915 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) |
| 916 | goto trap_recursive; |
| 917 | if (try_futile && |
| 918 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { |
| 919 | fail: |
| 920 | gh->gh_error = GLR_TRYFAILED; |
| 921 | gfs2_holder_wake(gh); |
| 922 | return; |
| 923 | } |
| 924 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
| 925 | continue; |
| 926 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) |
| 927 | insert_pt = &gh2->gh_list; |
| 928 | } |
| 929 | set_bit(GLF_QUEUED, &gl->gl_flags); |
| 930 | trace_gfs2_glock_queue(gh, 1); |
| 931 | gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT); |
| 932 | gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT); |
| 933 | if (likely(insert_pt == NULL)) { |
| 934 | list_add_tail(&gh->gh_list, &gl->gl_holders); |
| 935 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) |
| 936 | goto do_cancel; |
| 937 | return; |
| 938 | } |
| 939 | list_add_tail(&gh->gh_list, insert_pt); |
| 940 | do_cancel: |
| 941 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); |
| 942 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { |
| 943 | spin_unlock(&gl->gl_lockref.lock); |
| 944 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
| 945 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
| 946 | spin_lock(&gl->gl_lockref.lock); |
| 947 | } |
| 948 | return; |
| 949 | |
| 950 | trap_recursive: |
| 951 | pr_err("original: %pSR\n", (void *)gh2->gh_ip); |
| 952 | pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid)); |
| 953 | pr_err("lock type: %d req lock state : %d\n", |
| 954 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); |
| 955 | pr_err("new: %pSR\n", (void *)gh->gh_ip); |
| 956 | pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid)); |
| 957 | pr_err("lock type: %d req lock state : %d\n", |
| 958 | gh->gh_gl->gl_name.ln_type, gh->gh_state); |
| 959 | gfs2_dump_glock(NULL, gl); |
| 960 | BUG(); |
| 961 | } |
| 962 | |
| 963 | /** |
| 964 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) |
| 965 | * @gh: the holder structure |
| 966 | * |
| 967 | * if (gh->gh_flags & GL_ASYNC), this never returns an error |
| 968 | * |
| 969 | * Returns: 0, GLR_TRYFAILED, or errno on failure |
| 970 | */ |
| 971 | |
| 972 | int gfs2_glock_nq(struct gfs2_holder *gh) |
| 973 | { |
| 974 | struct gfs2_glock *gl = gh->gh_gl; |
| 975 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| 976 | int error = 0; |
| 977 | |
| 978 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
| 979 | return -EIO; |
| 980 | |
| 981 | if (test_bit(GLF_LRU, &gl->gl_flags)) |
| 982 | gfs2_glock_remove_from_lru(gl); |
| 983 | |
| 984 | spin_lock(&gl->gl_lockref.lock); |
| 985 | add_to_queue(gh); |
| 986 | if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) && |
| 987 | test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) { |
| 988 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| 989 | gl->gl_lockref.count++; |
| 990 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 991 | gl->gl_lockref.count--; |
| 992 | } |
| 993 | run_queue(gl, 1); |
| 994 | spin_unlock(&gl->gl_lockref.lock); |
| 995 | |
| 996 | if (!(gh->gh_flags & GL_ASYNC)) |
| 997 | error = gfs2_glock_wait(gh); |
| 998 | |
| 999 | return error; |
| 1000 | } |
| 1001 | |
| 1002 | /** |
| 1003 | * gfs2_glock_poll - poll to see if an async request has been completed |
| 1004 | * @gh: the holder |
| 1005 | * |
| 1006 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on |
| 1007 | */ |
| 1008 | |
| 1009 | int gfs2_glock_poll(struct gfs2_holder *gh) |
| 1010 | { |
| 1011 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
| 1012 | } |
| 1013 | |
| 1014 | /** |
| 1015 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) |
| 1016 | * @gh: the glock holder |
| 1017 | * |
| 1018 | */ |
| 1019 | |
| 1020 | void gfs2_glock_dq(struct gfs2_holder *gh) |
| 1021 | { |
| 1022 | struct gfs2_glock *gl = gh->gh_gl; |
| 1023 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
| 1024 | unsigned delay = 0; |
| 1025 | int fast_path = 0; |
| 1026 | |
| 1027 | spin_lock(&gl->gl_lockref.lock); |
| 1028 | if (gh->gh_flags & GL_NOCACHE) |
| 1029 | handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| 1030 | |
| 1031 | list_del_init(&gh->gh_list); |
| 1032 | clear_bit(HIF_HOLDER, &gh->gh_iflags); |
| 1033 | if (find_first_holder(gl) == NULL) { |
| 1034 | if (glops->go_unlock) { |
| 1035 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
| 1036 | spin_unlock(&gl->gl_lockref.lock); |
| 1037 | glops->go_unlock(gh); |
| 1038 | spin_lock(&gl->gl_lockref.lock); |
| 1039 | clear_bit(GLF_LOCK, &gl->gl_flags); |
| 1040 | } |
| 1041 | if (list_empty(&gl->gl_holders) && |
| 1042 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| 1043 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| 1044 | fast_path = 1; |
| 1045 | } |
| 1046 | if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl) && |
| 1047 | (glops->go_flags & GLOF_LRU)) |
| 1048 | gfs2_glock_add_to_lru(gl); |
| 1049 | |
| 1050 | trace_gfs2_glock_queue(gh, 0); |
| 1051 | spin_unlock(&gl->gl_lockref.lock); |
| 1052 | if (likely(fast_path)) |
| 1053 | return; |
| 1054 | |
| 1055 | gfs2_glock_hold(gl); |
| 1056 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| 1057 | !test_bit(GLF_DEMOTE, &gl->gl_flags) && |
| 1058 | gl->gl_name.ln_type == LM_TYPE_INODE) |
| 1059 | delay = gl->gl_hold_time; |
| 1060 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
| 1061 | gfs2_glock_put(gl); |
| 1062 | } |
| 1063 | |
| 1064 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
| 1065 | { |
| 1066 | struct gfs2_glock *gl = gh->gh_gl; |
| 1067 | gfs2_glock_dq(gh); |
| 1068 | might_sleep(); |
| 1069 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE); |
| 1070 | } |
| 1071 | |
| 1072 | /** |
| 1073 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it |
| 1074 | * @gh: the holder structure |
| 1075 | * |
| 1076 | */ |
| 1077 | |
| 1078 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) |
| 1079 | { |
| 1080 | gfs2_glock_dq(gh); |
| 1081 | gfs2_holder_uninit(gh); |
| 1082 | } |
| 1083 | |
| 1084 | /** |
| 1085 | * gfs2_glock_nq_num - acquire a glock based on lock number |
| 1086 | * @sdp: the filesystem |
| 1087 | * @number: the lock number |
| 1088 | * @glops: the glock operations for the type of glock |
| 1089 | * @state: the state to acquire the glock in |
| 1090 | * @flags: modifier flags for the acquisition |
| 1091 | * @gh: the struct gfs2_holder |
| 1092 | * |
| 1093 | * Returns: errno |
| 1094 | */ |
| 1095 | |
| 1096 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
| 1097 | const struct gfs2_glock_operations *glops, |
| 1098 | unsigned int state, u16 flags, struct gfs2_holder *gh) |
| 1099 | { |
| 1100 | struct gfs2_glock *gl; |
| 1101 | int error; |
| 1102 | |
| 1103 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); |
| 1104 | if (!error) { |
| 1105 | error = gfs2_glock_nq_init(gl, state, flags, gh); |
| 1106 | gfs2_glock_put(gl); |
| 1107 | } |
| 1108 | |
| 1109 | return error; |
| 1110 | } |
| 1111 | |
| 1112 | /** |
| 1113 | * glock_compare - Compare two struct gfs2_glock structures for sorting |
| 1114 | * @arg_a: the first structure |
| 1115 | * @arg_b: the second structure |
| 1116 | * |
| 1117 | */ |
| 1118 | |
| 1119 | static int glock_compare(const void *arg_a, const void *arg_b) |
| 1120 | { |
| 1121 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
| 1122 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; |
| 1123 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; |
| 1124 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; |
| 1125 | |
| 1126 | if (a->ln_number > b->ln_number) |
| 1127 | return 1; |
| 1128 | if (a->ln_number < b->ln_number) |
| 1129 | return -1; |
| 1130 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
| 1131 | return 0; |
| 1132 | } |
| 1133 | |
| 1134 | /** |
| 1135 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order |
| 1136 | * @num_gh: the number of structures |
| 1137 | * @ghs: an array of struct gfs2_holder structures |
| 1138 | * |
| 1139 | * Returns: 0 on success (all glocks acquired), |
| 1140 | * errno on failure (no glocks acquired) |
| 1141 | */ |
| 1142 | |
| 1143 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, |
| 1144 | struct gfs2_holder **p) |
| 1145 | { |
| 1146 | unsigned int x; |
| 1147 | int error = 0; |
| 1148 | |
| 1149 | for (x = 0; x < num_gh; x++) |
| 1150 | p[x] = &ghs[x]; |
| 1151 | |
| 1152 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); |
| 1153 | |
| 1154 | for (x = 0; x < num_gh; x++) { |
| 1155 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
| 1156 | |
| 1157 | error = gfs2_glock_nq(p[x]); |
| 1158 | if (error) { |
| 1159 | while (x--) |
| 1160 | gfs2_glock_dq(p[x]); |
| 1161 | break; |
| 1162 | } |
| 1163 | } |
| 1164 | |
| 1165 | return error; |
| 1166 | } |
| 1167 | |
| 1168 | /** |
| 1169 | * gfs2_glock_nq_m - acquire multiple glocks |
| 1170 | * @num_gh: the number of structures |
| 1171 | * @ghs: an array of struct gfs2_holder structures |
| 1172 | * |
| 1173 | * |
| 1174 | * Returns: 0 on success (all glocks acquired), |
| 1175 | * errno on failure (no glocks acquired) |
| 1176 | */ |
| 1177 | |
| 1178 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) |
| 1179 | { |
| 1180 | struct gfs2_holder *tmp[4]; |
| 1181 | struct gfs2_holder **pph = tmp; |
| 1182 | int error = 0; |
| 1183 | |
| 1184 | switch(num_gh) { |
| 1185 | case 0: |
| 1186 | return 0; |
| 1187 | case 1: |
| 1188 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
| 1189 | return gfs2_glock_nq(ghs); |
| 1190 | default: |
| 1191 | if (num_gh <= 4) |
| 1192 | break; |
| 1193 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
| 1194 | if (!pph) |
| 1195 | return -ENOMEM; |
| 1196 | } |
| 1197 | |
| 1198 | error = nq_m_sync(num_gh, ghs, pph); |
| 1199 | |
| 1200 | if (pph != tmp) |
| 1201 | kfree(pph); |
| 1202 | |
| 1203 | return error; |
| 1204 | } |
| 1205 | |
| 1206 | /** |
| 1207 | * gfs2_glock_dq_m - release multiple glocks |
| 1208 | * @num_gh: the number of structures |
| 1209 | * @ghs: an array of struct gfs2_holder structures |
| 1210 | * |
| 1211 | */ |
| 1212 | |
| 1213 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) |
| 1214 | { |
| 1215 | while (num_gh--) |
| 1216 | gfs2_glock_dq(&ghs[num_gh]); |
| 1217 | } |
| 1218 | |
| 1219 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
| 1220 | { |
| 1221 | unsigned long delay = 0; |
| 1222 | unsigned long holdtime; |
| 1223 | unsigned long now = jiffies; |
| 1224 | |
| 1225 | gfs2_glock_hold(gl); |
| 1226 | holdtime = gl->gl_tchange + gl->gl_hold_time; |
| 1227 | if (test_bit(GLF_QUEUED, &gl->gl_flags) && |
| 1228 | gl->gl_name.ln_type == LM_TYPE_INODE) { |
| 1229 | if (time_before(now, holdtime)) |
| 1230 | delay = holdtime - now; |
| 1231 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
| 1232 | delay = gl->gl_hold_time; |
| 1233 | } |
| 1234 | |
| 1235 | spin_lock(&gl->gl_lockref.lock); |
| 1236 | handle_callback(gl, state, delay, true); |
| 1237 | spin_unlock(&gl->gl_lockref.lock); |
| 1238 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
| 1239 | gfs2_glock_put(gl); |
| 1240 | } |
| 1241 | |
| 1242 | /** |
| 1243 | * gfs2_should_freeze - Figure out if glock should be frozen |
| 1244 | * @gl: The glock in question |
| 1245 | * |
| 1246 | * Glocks are not frozen if (a) the result of the dlm operation is |
| 1247 | * an error, (b) the locking operation was an unlock operation or |
| 1248 | * (c) if there is a "noexp" flagged request anywhere in the queue |
| 1249 | * |
| 1250 | * Returns: 1 if freezing should occur, 0 otherwise |
| 1251 | */ |
| 1252 | |
| 1253 | static int gfs2_should_freeze(const struct gfs2_glock *gl) |
| 1254 | { |
| 1255 | const struct gfs2_holder *gh; |
| 1256 | |
| 1257 | if (gl->gl_reply & ~LM_OUT_ST_MASK) |
| 1258 | return 0; |
| 1259 | if (gl->gl_target == LM_ST_UNLOCKED) |
| 1260 | return 0; |
| 1261 | |
| 1262 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| 1263 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| 1264 | continue; |
| 1265 | if (LM_FLAG_NOEXP & gh->gh_flags) |
| 1266 | return 0; |
| 1267 | } |
| 1268 | |
| 1269 | return 1; |
| 1270 | } |
| 1271 | |
| 1272 | /** |
| 1273 | * gfs2_glock_complete - Callback used by locking |
| 1274 | * @gl: Pointer to the glock |
| 1275 | * @ret: The return value from the dlm |
| 1276 | * |
| 1277 | * The gl_reply field is under the gl_lockref.lock lock so that it is ok |
| 1278 | * to use a bitfield shared with other glock state fields. |
| 1279 | */ |
| 1280 | |
| 1281 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
| 1282 | { |
| 1283 | struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct; |
| 1284 | |
| 1285 | spin_lock(&gl->gl_lockref.lock); |
| 1286 | gl->gl_reply = ret; |
| 1287 | |
| 1288 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) { |
| 1289 | if (gfs2_should_freeze(gl)) { |
| 1290 | set_bit(GLF_FROZEN, &gl->gl_flags); |
| 1291 | spin_unlock(&gl->gl_lockref.lock); |
| 1292 | return; |
| 1293 | } |
| 1294 | } |
| 1295 | |
| 1296 | gl->gl_lockref.count++; |
| 1297 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| 1298 | spin_unlock(&gl->gl_lockref.lock); |
| 1299 | |
| 1300 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 1301 | gfs2_glock_put(gl); |
| 1302 | } |
| 1303 | |
| 1304 | static int glock_cmp(void *priv, struct list_head *a, struct list_head *b) |
| 1305 | { |
| 1306 | struct gfs2_glock *gla, *glb; |
| 1307 | |
| 1308 | gla = list_entry(a, struct gfs2_glock, gl_lru); |
| 1309 | glb = list_entry(b, struct gfs2_glock, gl_lru); |
| 1310 | |
| 1311 | if (gla->gl_name.ln_number > glb->gl_name.ln_number) |
| 1312 | return 1; |
| 1313 | if (gla->gl_name.ln_number < glb->gl_name.ln_number) |
| 1314 | return -1; |
| 1315 | |
| 1316 | return 0; |
| 1317 | } |
| 1318 | |
| 1319 | /** |
| 1320 | * gfs2_dispose_glock_lru - Demote a list of glocks |
| 1321 | * @list: The list to dispose of |
| 1322 | * |
| 1323 | * Disposing of glocks may involve disk accesses, so that here we sort |
| 1324 | * the glocks by number (i.e. disk location of the inodes) so that if |
| 1325 | * there are any such accesses, they'll be sent in order (mostly). |
| 1326 | * |
| 1327 | * Must be called under the lru_lock, but may drop and retake this |
| 1328 | * lock. While the lru_lock is dropped, entries may vanish from the |
| 1329 | * list, but no new entries will appear on the list (since it is |
| 1330 | * private) |
| 1331 | */ |
| 1332 | |
| 1333 | static void gfs2_dispose_glock_lru(struct list_head *list) |
| 1334 | __releases(&lru_lock) |
| 1335 | __acquires(&lru_lock) |
| 1336 | { |
| 1337 | struct gfs2_glock *gl; |
| 1338 | |
| 1339 | list_sort(NULL, list, glock_cmp); |
| 1340 | |
| 1341 | while(!list_empty(list)) { |
| 1342 | gl = list_entry(list->next, struct gfs2_glock, gl_lru); |
| 1343 | list_del_init(&gl->gl_lru); |
| 1344 | if (!spin_trylock(&gl->gl_lockref.lock)) { |
| 1345 | add_back_to_lru: |
| 1346 | list_add(&gl->gl_lru, &lru_list); |
| 1347 | atomic_inc(&lru_count); |
| 1348 | continue; |
| 1349 | } |
| 1350 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
| 1351 | spin_unlock(&gl->gl_lockref.lock); |
| 1352 | goto add_back_to_lru; |
| 1353 | } |
| 1354 | clear_bit(GLF_LRU, &gl->gl_flags); |
| 1355 | gl->gl_lockref.count++; |
| 1356 | if (demote_ok(gl)) |
| 1357 | handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| 1358 | WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags)); |
| 1359 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 1360 | gl->gl_lockref.count--; |
| 1361 | spin_unlock(&gl->gl_lockref.lock); |
| 1362 | cond_resched_lock(&lru_lock); |
| 1363 | } |
| 1364 | } |
| 1365 | |
| 1366 | /** |
| 1367 | * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote |
| 1368 | * @nr: The number of entries to scan |
| 1369 | * |
| 1370 | * This function selects the entries on the LRU which are able to |
| 1371 | * be demoted, and then kicks off the process by calling |
| 1372 | * gfs2_dispose_glock_lru() above. |
| 1373 | */ |
| 1374 | |
| 1375 | static long gfs2_scan_glock_lru(int nr) |
| 1376 | { |
| 1377 | struct gfs2_glock *gl; |
| 1378 | LIST_HEAD(skipped); |
| 1379 | LIST_HEAD(dispose); |
| 1380 | long freed = 0; |
| 1381 | |
| 1382 | spin_lock(&lru_lock); |
| 1383 | while ((nr-- >= 0) && !list_empty(&lru_list)) { |
| 1384 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); |
| 1385 | |
| 1386 | /* Test for being demotable */ |
| 1387 | if (!test_bit(GLF_LOCK, &gl->gl_flags)) { |
| 1388 | list_move(&gl->gl_lru, &dispose); |
| 1389 | atomic_dec(&lru_count); |
| 1390 | freed++; |
| 1391 | continue; |
| 1392 | } |
| 1393 | |
| 1394 | list_move(&gl->gl_lru, &skipped); |
| 1395 | } |
| 1396 | list_splice(&skipped, &lru_list); |
| 1397 | if (!list_empty(&dispose)) |
| 1398 | gfs2_dispose_glock_lru(&dispose); |
| 1399 | spin_unlock(&lru_lock); |
| 1400 | |
| 1401 | return freed; |
| 1402 | } |
| 1403 | |
| 1404 | static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink, |
| 1405 | struct shrink_control *sc) |
| 1406 | { |
| 1407 | if (!(sc->gfp_mask & __GFP_FS)) |
| 1408 | return SHRINK_STOP; |
| 1409 | return gfs2_scan_glock_lru(sc->nr_to_scan); |
| 1410 | } |
| 1411 | |
| 1412 | static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink, |
| 1413 | struct shrink_control *sc) |
| 1414 | { |
| 1415 | return vfs_pressure_ratio(atomic_read(&lru_count)); |
| 1416 | } |
| 1417 | |
| 1418 | static struct shrinker glock_shrinker = { |
| 1419 | .seeks = DEFAULT_SEEKS, |
| 1420 | .count_objects = gfs2_glock_shrink_count, |
| 1421 | .scan_objects = gfs2_glock_shrink_scan, |
| 1422 | }; |
| 1423 | |
| 1424 | /** |
| 1425 | * examine_bucket - Call a function for glock in a hash bucket |
| 1426 | * @examiner: the function |
| 1427 | * @sdp: the filesystem |
| 1428 | * @bucket: the bucket |
| 1429 | * |
| 1430 | */ |
| 1431 | |
| 1432 | static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) |
| 1433 | { |
| 1434 | struct gfs2_glock *gl; |
| 1435 | struct rhash_head *pos; |
| 1436 | const struct bucket_table *tbl; |
| 1437 | int i; |
| 1438 | |
| 1439 | rcu_read_lock(); |
| 1440 | tbl = rht_dereference_rcu(gl_hash_table.tbl, &gl_hash_table); |
| 1441 | for (i = 0; i < tbl->size; i++) { |
| 1442 | rht_for_each_entry_rcu(gl, pos, tbl, i, gl_node) { |
| 1443 | if ((gl->gl_name.ln_sbd == sdp) && |
| 1444 | lockref_get_not_dead(&gl->gl_lockref)) |
| 1445 | examiner(gl); |
| 1446 | } |
| 1447 | } |
| 1448 | rcu_read_unlock(); |
| 1449 | cond_resched(); |
| 1450 | } |
| 1451 | |
| 1452 | /** |
| 1453 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting |
| 1454 | * @gl: The glock to thaw |
| 1455 | * |
| 1456 | */ |
| 1457 | |
| 1458 | static void thaw_glock(struct gfs2_glock *gl) |
| 1459 | { |
| 1460 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) |
| 1461 | goto out; |
| 1462 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| 1463 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) { |
| 1464 | out: |
| 1465 | gfs2_glock_put(gl); |
| 1466 | } |
| 1467 | } |
| 1468 | |
| 1469 | /** |
| 1470 | * clear_glock - look at a glock and see if we can free it from glock cache |
| 1471 | * @gl: the glock to look at |
| 1472 | * |
| 1473 | */ |
| 1474 | |
| 1475 | static void clear_glock(struct gfs2_glock *gl) |
| 1476 | { |
| 1477 | gfs2_glock_remove_from_lru(gl); |
| 1478 | |
| 1479 | spin_lock(&gl->gl_lockref.lock); |
| 1480 | if (gl->gl_state != LM_ST_UNLOCKED) |
| 1481 | handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| 1482 | spin_unlock(&gl->gl_lockref.lock); |
| 1483 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| 1484 | gfs2_glock_put(gl); |
| 1485 | } |
| 1486 | |
| 1487 | /** |
| 1488 | * gfs2_glock_thaw - Thaw any frozen glocks |
| 1489 | * @sdp: The super block |
| 1490 | * |
| 1491 | */ |
| 1492 | |
| 1493 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) |
| 1494 | { |
| 1495 | glock_hash_walk(thaw_glock, sdp); |
| 1496 | } |
| 1497 | |
| 1498 | static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
| 1499 | { |
| 1500 | spin_lock(&gl->gl_lockref.lock); |
| 1501 | gfs2_dump_glock(seq, gl); |
| 1502 | spin_unlock(&gl->gl_lockref.lock); |
| 1503 | } |
| 1504 | |
| 1505 | static void dump_glock_func(struct gfs2_glock *gl) |
| 1506 | { |
| 1507 | dump_glock(NULL, gl); |
| 1508 | } |
| 1509 | |
| 1510 | /** |
| 1511 | * gfs2_gl_hash_clear - Empty out the glock hash table |
| 1512 | * @sdp: the filesystem |
| 1513 | * @wait: wait until it's all gone |
| 1514 | * |
| 1515 | * Called when unmounting the filesystem. |
| 1516 | */ |
| 1517 | |
| 1518 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
| 1519 | { |
| 1520 | set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags); |
| 1521 | flush_workqueue(glock_workqueue); |
| 1522 | glock_hash_walk(clear_glock, sdp); |
| 1523 | flush_workqueue(glock_workqueue); |
| 1524 | wait_event_timeout(sdp->sd_glock_wait, |
| 1525 | atomic_read(&sdp->sd_glock_disposal) == 0, |
| 1526 | HZ * 600); |
| 1527 | glock_hash_walk(dump_glock_func, sdp); |
| 1528 | } |
| 1529 | |
| 1530 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
| 1531 | { |
| 1532 | struct gfs2_glock *gl = ip->i_gl; |
| 1533 | int ret; |
| 1534 | |
| 1535 | ret = gfs2_truncatei_resume(ip); |
| 1536 | gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0); |
| 1537 | |
| 1538 | spin_lock(&gl->gl_lockref.lock); |
| 1539 | clear_bit(GLF_LOCK, &gl->gl_flags); |
| 1540 | run_queue(gl, 1); |
| 1541 | spin_unlock(&gl->gl_lockref.lock); |
| 1542 | } |
| 1543 | |
| 1544 | static const char *state2str(unsigned state) |
| 1545 | { |
| 1546 | switch(state) { |
| 1547 | case LM_ST_UNLOCKED: |
| 1548 | return "UN"; |
| 1549 | case LM_ST_SHARED: |
| 1550 | return "SH"; |
| 1551 | case LM_ST_DEFERRED: |
| 1552 | return "DF"; |
| 1553 | case LM_ST_EXCLUSIVE: |
| 1554 | return "EX"; |
| 1555 | } |
| 1556 | return "??"; |
| 1557 | } |
| 1558 | |
| 1559 | static const char *hflags2str(char *buf, u16 flags, unsigned long iflags) |
| 1560 | { |
| 1561 | char *p = buf; |
| 1562 | if (flags & LM_FLAG_TRY) |
| 1563 | *p++ = 't'; |
| 1564 | if (flags & LM_FLAG_TRY_1CB) |
| 1565 | *p++ = 'T'; |
| 1566 | if (flags & LM_FLAG_NOEXP) |
| 1567 | *p++ = 'e'; |
| 1568 | if (flags & LM_FLAG_ANY) |
| 1569 | *p++ = 'A'; |
| 1570 | if (flags & LM_FLAG_PRIORITY) |
| 1571 | *p++ = 'p'; |
| 1572 | if (flags & GL_ASYNC) |
| 1573 | *p++ = 'a'; |
| 1574 | if (flags & GL_EXACT) |
| 1575 | *p++ = 'E'; |
| 1576 | if (flags & GL_NOCACHE) |
| 1577 | *p++ = 'c'; |
| 1578 | if (test_bit(HIF_HOLDER, &iflags)) |
| 1579 | *p++ = 'H'; |
| 1580 | if (test_bit(HIF_WAIT, &iflags)) |
| 1581 | *p++ = 'W'; |
| 1582 | if (test_bit(HIF_FIRST, &iflags)) |
| 1583 | *p++ = 'F'; |
| 1584 | *p = 0; |
| 1585 | return buf; |
| 1586 | } |
| 1587 | |
| 1588 | /** |
| 1589 | * dump_holder - print information about a glock holder |
| 1590 | * @seq: the seq_file struct |
| 1591 | * @gh: the glock holder |
| 1592 | * |
| 1593 | */ |
| 1594 | |
| 1595 | static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
| 1596 | { |
| 1597 | struct task_struct *gh_owner = NULL; |
| 1598 | char flags_buf[32]; |
| 1599 | |
| 1600 | rcu_read_lock(); |
| 1601 | if (gh->gh_owner_pid) |
| 1602 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
| 1603 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n", |
| 1604 | state2str(gh->gh_state), |
| 1605 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), |
| 1606 | gh->gh_error, |
| 1607 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, |
| 1608 | gh_owner ? gh_owner->comm : "(ended)", |
| 1609 | (void *)gh->gh_ip); |
| 1610 | rcu_read_unlock(); |
| 1611 | } |
| 1612 | |
| 1613 | static const char *gflags2str(char *buf, const struct gfs2_glock *gl) |
| 1614 | { |
| 1615 | const unsigned long *gflags = &gl->gl_flags; |
| 1616 | char *p = buf; |
| 1617 | |
| 1618 | if (test_bit(GLF_LOCK, gflags)) |
| 1619 | *p++ = 'l'; |
| 1620 | if (test_bit(GLF_DEMOTE, gflags)) |
| 1621 | *p++ = 'D'; |
| 1622 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) |
| 1623 | *p++ = 'd'; |
| 1624 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) |
| 1625 | *p++ = 'p'; |
| 1626 | if (test_bit(GLF_DIRTY, gflags)) |
| 1627 | *p++ = 'y'; |
| 1628 | if (test_bit(GLF_LFLUSH, gflags)) |
| 1629 | *p++ = 'f'; |
| 1630 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) |
| 1631 | *p++ = 'i'; |
| 1632 | if (test_bit(GLF_REPLY_PENDING, gflags)) |
| 1633 | *p++ = 'r'; |
| 1634 | if (test_bit(GLF_INITIAL, gflags)) |
| 1635 | *p++ = 'I'; |
| 1636 | if (test_bit(GLF_FROZEN, gflags)) |
| 1637 | *p++ = 'F'; |
| 1638 | if (test_bit(GLF_QUEUED, gflags)) |
| 1639 | *p++ = 'q'; |
| 1640 | if (test_bit(GLF_LRU, gflags)) |
| 1641 | *p++ = 'L'; |
| 1642 | if (gl->gl_object) |
| 1643 | *p++ = 'o'; |
| 1644 | if (test_bit(GLF_BLOCKING, gflags)) |
| 1645 | *p++ = 'b'; |
| 1646 | *p = 0; |
| 1647 | return buf; |
| 1648 | } |
| 1649 | |
| 1650 | /** |
| 1651 | * gfs2_dump_glock - print information about a glock |
| 1652 | * @seq: The seq_file struct |
| 1653 | * @gl: the glock |
| 1654 | * |
| 1655 | * The file format is as follows: |
| 1656 | * One line per object, capital letters are used to indicate objects |
| 1657 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, |
| 1658 | * other objects are indented by a single space and follow the glock to |
| 1659 | * which they are related. Fields are indicated by lower case letters |
| 1660 | * followed by a colon and the field value, except for strings which are in |
| 1661 | * [] so that its possible to see if they are composed of spaces for |
| 1662 | * example. The field's are n = number (id of the object), f = flags, |
| 1663 | * t = type, s = state, r = refcount, e = error, p = pid. |
| 1664 | * |
| 1665 | */ |
| 1666 | |
| 1667 | void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
| 1668 | { |
| 1669 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
| 1670 | unsigned long long dtime; |
| 1671 | const struct gfs2_holder *gh; |
| 1672 | char gflags_buf[32]; |
| 1673 | |
| 1674 | dtime = jiffies - gl->gl_demote_time; |
| 1675 | dtime *= 1000000/HZ; /* demote time in uSec */ |
| 1676 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| 1677 | dtime = 0; |
| 1678 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d m:%ld\n", |
| 1679 | state2str(gl->gl_state), |
| 1680 | gl->gl_name.ln_type, |
| 1681 | (unsigned long long)gl->gl_name.ln_number, |
| 1682 | gflags2str(gflags_buf, gl), |
| 1683 | state2str(gl->gl_target), |
| 1684 | state2str(gl->gl_demote_state), dtime, |
| 1685 | atomic_read(&gl->gl_ail_count), |
| 1686 | atomic_read(&gl->gl_revokes), |
| 1687 | (int)gl->gl_lockref.count, gl->gl_hold_time); |
| 1688 | |
| 1689 | list_for_each_entry(gh, &gl->gl_holders, gh_list) |
| 1690 | dump_holder(seq, gh); |
| 1691 | |
| 1692 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
| 1693 | glops->go_dump(seq, gl); |
| 1694 | } |
| 1695 | |
| 1696 | static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr) |
| 1697 | { |
| 1698 | struct gfs2_glock *gl = iter_ptr; |
| 1699 | |
| 1700 | seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n", |
| 1701 | gl->gl_name.ln_type, |
| 1702 | (unsigned long long)gl->gl_name.ln_number, |
| 1703 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT], |
| 1704 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR], |
| 1705 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB], |
| 1706 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB], |
| 1707 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT], |
| 1708 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR], |
| 1709 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT], |
| 1710 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]); |
| 1711 | return 0; |
| 1712 | } |
| 1713 | |
| 1714 | static const char *gfs2_gltype[] = { |
| 1715 | "type", |
| 1716 | "reserved", |
| 1717 | "nondisk", |
| 1718 | "inode", |
| 1719 | "rgrp", |
| 1720 | "meta", |
| 1721 | "iopen", |
| 1722 | "flock", |
| 1723 | "plock", |
| 1724 | "quota", |
| 1725 | "journal", |
| 1726 | }; |
| 1727 | |
| 1728 | static const char *gfs2_stype[] = { |
| 1729 | [GFS2_LKS_SRTT] = "srtt", |
| 1730 | [GFS2_LKS_SRTTVAR] = "srttvar", |
| 1731 | [GFS2_LKS_SRTTB] = "srttb", |
| 1732 | [GFS2_LKS_SRTTVARB] = "srttvarb", |
| 1733 | [GFS2_LKS_SIRT] = "sirt", |
| 1734 | [GFS2_LKS_SIRTVAR] = "sirtvar", |
| 1735 | [GFS2_LKS_DCOUNT] = "dlm", |
| 1736 | [GFS2_LKS_QCOUNT] = "queue", |
| 1737 | }; |
| 1738 | |
| 1739 | #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype)) |
| 1740 | |
| 1741 | static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr) |
| 1742 | { |
| 1743 | struct gfs2_sbd *sdp = seq->private; |
| 1744 | loff_t pos = *(loff_t *)iter_ptr; |
| 1745 | unsigned index = pos >> 3; |
| 1746 | unsigned subindex = pos & 0x07; |
| 1747 | int i; |
| 1748 | |
| 1749 | if (index == 0 && subindex != 0) |
| 1750 | return 0; |
| 1751 | |
| 1752 | seq_printf(seq, "%-10s %8s:", gfs2_gltype[index], |
| 1753 | (index == 0) ? "cpu": gfs2_stype[subindex]); |
| 1754 | |
| 1755 | for_each_possible_cpu(i) { |
| 1756 | const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i); |
| 1757 | |
| 1758 | if (index == 0) |
| 1759 | seq_printf(seq, " %15u", i); |
| 1760 | else |
| 1761 | seq_printf(seq, " %15llu", (unsigned long long)lkstats-> |
| 1762 | lkstats[index - 1].stats[subindex]); |
| 1763 | } |
| 1764 | seq_putc(seq, '\n'); |
| 1765 | return 0; |
| 1766 | } |
| 1767 | |
| 1768 | int __init gfs2_glock_init(void) |
| 1769 | { |
| 1770 | int ret; |
| 1771 | |
| 1772 | ret = rhashtable_init(&gl_hash_table, &ht_parms); |
| 1773 | if (ret < 0) |
| 1774 | return ret; |
| 1775 | |
| 1776 | glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | |
| 1777 | WQ_HIGHPRI | WQ_FREEZABLE, 0); |
| 1778 | if (!glock_workqueue) { |
| 1779 | rhashtable_destroy(&gl_hash_table); |
| 1780 | return -ENOMEM; |
| 1781 | } |
| 1782 | gfs2_delete_workqueue = alloc_workqueue("delete_workqueue", |
| 1783 | WQ_MEM_RECLAIM | WQ_FREEZABLE, |
| 1784 | 0); |
| 1785 | if (!gfs2_delete_workqueue) { |
| 1786 | destroy_workqueue(glock_workqueue); |
| 1787 | rhashtable_destroy(&gl_hash_table); |
| 1788 | return -ENOMEM; |
| 1789 | } |
| 1790 | |
| 1791 | register_shrinker(&glock_shrinker); |
| 1792 | |
| 1793 | return 0; |
| 1794 | } |
| 1795 | |
| 1796 | void gfs2_glock_exit(void) |
| 1797 | { |
| 1798 | unregister_shrinker(&glock_shrinker); |
| 1799 | rhashtable_destroy(&gl_hash_table); |
| 1800 | destroy_workqueue(glock_workqueue); |
| 1801 | destroy_workqueue(gfs2_delete_workqueue); |
| 1802 | } |
| 1803 | |
| 1804 | static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
| 1805 | { |
| 1806 | do { |
| 1807 | gi->gl = rhashtable_walk_next(&gi->hti); |
| 1808 | if (IS_ERR(gi->gl)) { |
| 1809 | if (PTR_ERR(gi->gl) == -EAGAIN) |
| 1810 | continue; |
| 1811 | gi->gl = NULL; |
| 1812 | } |
| 1813 | /* Skip entries for other sb and dead entries */ |
| 1814 | } while ((gi->gl) && ((gi->sdp != gi->gl->gl_name.ln_sbd) || |
| 1815 | __lockref_is_dead(&gi->gl->gl_lockref))); |
| 1816 | } |
| 1817 | |
| 1818 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
| 1819 | { |
| 1820 | struct gfs2_glock_iter *gi = seq->private; |
| 1821 | loff_t n = *pos; |
| 1822 | int ret; |
| 1823 | |
| 1824 | if (gi->last_pos <= *pos) |
| 1825 | n = (*pos - gi->last_pos); |
| 1826 | |
| 1827 | ret = rhashtable_walk_start(&gi->hti); |
| 1828 | if (ret) |
| 1829 | return NULL; |
| 1830 | |
| 1831 | do { |
| 1832 | gfs2_glock_iter_next(gi); |
| 1833 | } while (gi->gl && n--); |
| 1834 | |
| 1835 | gi->last_pos = *pos; |
| 1836 | return gi->gl; |
| 1837 | } |
| 1838 | |
| 1839 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
| 1840 | loff_t *pos) |
| 1841 | { |
| 1842 | struct gfs2_glock_iter *gi = seq->private; |
| 1843 | |
| 1844 | (*pos)++; |
| 1845 | gi->last_pos = *pos; |
| 1846 | gfs2_glock_iter_next(gi); |
| 1847 | return gi->gl; |
| 1848 | } |
| 1849 | |
| 1850 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
| 1851 | { |
| 1852 | struct gfs2_glock_iter *gi = seq->private; |
| 1853 | |
| 1854 | gi->gl = NULL; |
| 1855 | rhashtable_walk_stop(&gi->hti); |
| 1856 | } |
| 1857 | |
| 1858 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
| 1859 | { |
| 1860 | dump_glock(seq, iter_ptr); |
| 1861 | return 0; |
| 1862 | } |
| 1863 | |
| 1864 | static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos) |
| 1865 | { |
| 1866 | preempt_disable(); |
| 1867 | if (*pos >= GFS2_NR_SBSTATS) |
| 1868 | return NULL; |
| 1869 | return pos; |
| 1870 | } |
| 1871 | |
| 1872 | static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr, |
| 1873 | loff_t *pos) |
| 1874 | { |
| 1875 | (*pos)++; |
| 1876 | if (*pos >= GFS2_NR_SBSTATS) |
| 1877 | return NULL; |
| 1878 | return pos; |
| 1879 | } |
| 1880 | |
| 1881 | static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr) |
| 1882 | { |
| 1883 | preempt_enable(); |
| 1884 | } |
| 1885 | |
| 1886 | static const struct seq_operations gfs2_glock_seq_ops = { |
| 1887 | .start = gfs2_glock_seq_start, |
| 1888 | .next = gfs2_glock_seq_next, |
| 1889 | .stop = gfs2_glock_seq_stop, |
| 1890 | .show = gfs2_glock_seq_show, |
| 1891 | }; |
| 1892 | |
| 1893 | static const struct seq_operations gfs2_glstats_seq_ops = { |
| 1894 | .start = gfs2_glock_seq_start, |
| 1895 | .next = gfs2_glock_seq_next, |
| 1896 | .stop = gfs2_glock_seq_stop, |
| 1897 | .show = gfs2_glstats_seq_show, |
| 1898 | }; |
| 1899 | |
| 1900 | static const struct seq_operations gfs2_sbstats_seq_ops = { |
| 1901 | .start = gfs2_sbstats_seq_start, |
| 1902 | .next = gfs2_sbstats_seq_next, |
| 1903 | .stop = gfs2_sbstats_seq_stop, |
| 1904 | .show = gfs2_sbstats_seq_show, |
| 1905 | }; |
| 1906 | |
| 1907 | #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL) |
| 1908 | |
| 1909 | static int gfs2_glocks_open(struct inode *inode, struct file *file) |
| 1910 | { |
| 1911 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
| 1912 | sizeof(struct gfs2_glock_iter)); |
| 1913 | if (ret == 0) { |
| 1914 | struct seq_file *seq = file->private_data; |
| 1915 | struct gfs2_glock_iter *gi = seq->private; |
| 1916 | |
| 1917 | gi->sdp = inode->i_private; |
| 1918 | gi->last_pos = 0; |
| 1919 | seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN); |
| 1920 | if (seq->buf) |
| 1921 | seq->size = GFS2_SEQ_GOODSIZE; |
| 1922 | gi->gl = NULL; |
| 1923 | ret = rhashtable_walk_init(&gl_hash_table, &gi->hti, GFP_KERNEL); |
| 1924 | } |
| 1925 | return ret; |
| 1926 | } |
| 1927 | |
| 1928 | static int gfs2_glocks_release(struct inode *inode, struct file *file) |
| 1929 | { |
| 1930 | struct seq_file *seq = file->private_data; |
| 1931 | struct gfs2_glock_iter *gi = seq->private; |
| 1932 | |
| 1933 | gi->gl = NULL; |
| 1934 | rhashtable_walk_exit(&gi->hti); |
| 1935 | return seq_release_private(inode, file); |
| 1936 | } |
| 1937 | |
| 1938 | static int gfs2_glstats_open(struct inode *inode, struct file *file) |
| 1939 | { |
| 1940 | int ret = seq_open_private(file, &gfs2_glstats_seq_ops, |
| 1941 | sizeof(struct gfs2_glock_iter)); |
| 1942 | if (ret == 0) { |
| 1943 | struct seq_file *seq = file->private_data; |
| 1944 | struct gfs2_glock_iter *gi = seq->private; |
| 1945 | gi->sdp = inode->i_private; |
| 1946 | gi->last_pos = 0; |
| 1947 | seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN); |
| 1948 | if (seq->buf) |
| 1949 | seq->size = GFS2_SEQ_GOODSIZE; |
| 1950 | gi->gl = NULL; |
| 1951 | ret = rhashtable_walk_init(&gl_hash_table, &gi->hti, GFP_KERNEL); |
| 1952 | } |
| 1953 | return ret; |
| 1954 | } |
| 1955 | |
| 1956 | static int gfs2_sbstats_open(struct inode *inode, struct file *file) |
| 1957 | { |
| 1958 | int ret = seq_open(file, &gfs2_sbstats_seq_ops); |
| 1959 | if (ret == 0) { |
| 1960 | struct seq_file *seq = file->private_data; |
| 1961 | seq->private = inode->i_private; /* sdp */ |
| 1962 | } |
| 1963 | return ret; |
| 1964 | } |
| 1965 | |
| 1966 | static const struct file_operations gfs2_glocks_fops = { |
| 1967 | .owner = THIS_MODULE, |
| 1968 | .open = gfs2_glocks_open, |
| 1969 | .read = seq_read, |
| 1970 | .llseek = seq_lseek, |
| 1971 | .release = gfs2_glocks_release, |
| 1972 | }; |
| 1973 | |
| 1974 | static const struct file_operations gfs2_glstats_fops = { |
| 1975 | .owner = THIS_MODULE, |
| 1976 | .open = gfs2_glstats_open, |
| 1977 | .read = seq_read, |
| 1978 | .llseek = seq_lseek, |
| 1979 | .release = gfs2_glocks_release, |
| 1980 | }; |
| 1981 | |
| 1982 | static const struct file_operations gfs2_sbstats_fops = { |
| 1983 | .owner = THIS_MODULE, |
| 1984 | .open = gfs2_sbstats_open, |
| 1985 | .read = seq_read, |
| 1986 | .llseek = seq_lseek, |
| 1987 | .release = seq_release, |
| 1988 | }; |
| 1989 | |
| 1990 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) |
| 1991 | { |
| 1992 | struct dentry *dent; |
| 1993 | |
| 1994 | dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
| 1995 | if (IS_ERR_OR_NULL(dent)) |
| 1996 | goto fail; |
| 1997 | sdp->debugfs_dir = dent; |
| 1998 | |
| 1999 | dent = debugfs_create_file("glocks", |
| 2000 | S_IFREG | S_IRUGO, |
| 2001 | sdp->debugfs_dir, sdp, |
| 2002 | &gfs2_glocks_fops); |
| 2003 | if (IS_ERR_OR_NULL(dent)) |
| 2004 | goto fail; |
| 2005 | sdp->debugfs_dentry_glocks = dent; |
| 2006 | |
| 2007 | dent = debugfs_create_file("glstats", |
| 2008 | S_IFREG | S_IRUGO, |
| 2009 | sdp->debugfs_dir, sdp, |
| 2010 | &gfs2_glstats_fops); |
| 2011 | if (IS_ERR_OR_NULL(dent)) |
| 2012 | goto fail; |
| 2013 | sdp->debugfs_dentry_glstats = dent; |
| 2014 | |
| 2015 | dent = debugfs_create_file("sbstats", |
| 2016 | S_IFREG | S_IRUGO, |
| 2017 | sdp->debugfs_dir, sdp, |
| 2018 | &gfs2_sbstats_fops); |
| 2019 | if (IS_ERR_OR_NULL(dent)) |
| 2020 | goto fail; |
| 2021 | sdp->debugfs_dentry_sbstats = dent; |
| 2022 | |
| 2023 | return 0; |
| 2024 | fail: |
| 2025 | gfs2_delete_debugfs_file(sdp); |
| 2026 | return dent ? PTR_ERR(dent) : -ENOMEM; |
| 2027 | } |
| 2028 | |
| 2029 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) |
| 2030 | { |
| 2031 | if (sdp->debugfs_dir) { |
| 2032 | if (sdp->debugfs_dentry_glocks) { |
| 2033 | debugfs_remove(sdp->debugfs_dentry_glocks); |
| 2034 | sdp->debugfs_dentry_glocks = NULL; |
| 2035 | } |
| 2036 | if (sdp->debugfs_dentry_glstats) { |
| 2037 | debugfs_remove(sdp->debugfs_dentry_glstats); |
| 2038 | sdp->debugfs_dentry_glstats = NULL; |
| 2039 | } |
| 2040 | if (sdp->debugfs_dentry_sbstats) { |
| 2041 | debugfs_remove(sdp->debugfs_dentry_sbstats); |
| 2042 | sdp->debugfs_dentry_sbstats = NULL; |
| 2043 | } |
| 2044 | debugfs_remove(sdp->debugfs_dir); |
| 2045 | sdp->debugfs_dir = NULL; |
| 2046 | } |
| 2047 | } |
| 2048 | |
| 2049 | int gfs2_register_debugfs(void) |
| 2050 | { |
| 2051 | gfs2_root = debugfs_create_dir("gfs2", NULL); |
| 2052 | if (IS_ERR(gfs2_root)) |
| 2053 | return PTR_ERR(gfs2_root); |
| 2054 | return gfs2_root ? 0 : -ENOMEM; |
| 2055 | } |
| 2056 | |
| 2057 | void gfs2_unregister_debugfs(void) |
| 2058 | { |
| 2059 | debugfs_remove(gfs2_root); |
| 2060 | gfs2_root = NULL; |
| 2061 | } |