Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 1 | /* -*- mode: c; c-basic-offset: 8; -*- |
| 2 | * vim: noexpandtab sw=8 ts=8 sts=0: |
| 3 | * |
| 4 | * userdlm.c |
| 5 | * |
| 6 | * Code which implements the kernel side of a minimal userspace |
| 7 | * interface to our DLM. |
| 8 | * |
| 9 | * Many of the functions here are pared down versions of dlmglue.c |
| 10 | * functions. |
| 11 | * |
| 12 | * Copyright (C) 2003, 2004 Oracle. All rights reserved. |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or |
| 15 | * modify it under the terms of the GNU General Public |
| 16 | * License as published by the Free Software Foundation; either |
| 17 | * version 2 of the License, or (at your option) any later version. |
| 18 | * |
| 19 | * This program is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 22 | * General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public |
| 25 | * License along with this program; if not, write to the |
| 26 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 27 | * Boston, MA 021110-1307, USA. |
| 28 | */ |
| 29 | |
Jeff Mahoney | aee93ac | 2006-01-09 12:36:40 -0500 | [diff] [blame] | 30 | #include <linux/signal.h> |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 31 | |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/fs.h> |
| 34 | #include <linux/types.h> |
| 35 | #include <linux/crc32.h> |
| 36 | |
| 37 | |
| 38 | #include "cluster/nodemanager.h" |
| 39 | #include "cluster/heartbeat.h" |
| 40 | #include "cluster/tcp.h" |
| 41 | |
| 42 | #include "dlmapi.h" |
| 43 | |
| 44 | #include "userdlm.h" |
| 45 | |
| 46 | #define MLOG_MASK_PREFIX ML_DLMFS |
| 47 | #include "cluster/masklog.h" |
| 48 | |
| 49 | static inline int user_check_wait_flag(struct user_lock_res *lockres, |
| 50 | int flag) |
| 51 | { |
| 52 | int ret; |
| 53 | |
| 54 | spin_lock(&lockres->l_lock); |
| 55 | ret = lockres->l_flags & flag; |
| 56 | spin_unlock(&lockres->l_lock); |
| 57 | |
| 58 | return ret; |
| 59 | } |
| 60 | |
| 61 | static inline void user_wait_on_busy_lock(struct user_lock_res *lockres) |
| 62 | |
| 63 | { |
| 64 | wait_event(lockres->l_event, |
| 65 | !user_check_wait_flag(lockres, USER_LOCK_BUSY)); |
| 66 | } |
| 67 | |
| 68 | static inline void user_wait_on_blocked_lock(struct user_lock_res *lockres) |
| 69 | |
| 70 | { |
| 71 | wait_event(lockres->l_event, |
| 72 | !user_check_wait_flag(lockres, USER_LOCK_BLOCKED)); |
| 73 | } |
| 74 | |
| 75 | /* I heart container_of... */ |
| 76 | static inline struct dlm_ctxt * |
| 77 | dlm_ctxt_from_user_lockres(struct user_lock_res *lockres) |
| 78 | { |
| 79 | struct dlmfs_inode_private *ip; |
| 80 | |
| 81 | ip = container_of(lockres, |
| 82 | struct dlmfs_inode_private, |
| 83 | ip_lockres); |
| 84 | return ip->ip_dlm; |
| 85 | } |
| 86 | |
| 87 | static struct inode * |
| 88 | user_dlm_inode_from_user_lockres(struct user_lock_res *lockres) |
| 89 | { |
| 90 | struct dlmfs_inode_private *ip; |
| 91 | |
| 92 | ip = container_of(lockres, |
| 93 | struct dlmfs_inode_private, |
| 94 | ip_lockres); |
| 95 | return &ip->ip_vfs_inode; |
| 96 | } |
| 97 | |
| 98 | static inline void user_recover_from_dlm_error(struct user_lock_res *lockres) |
| 99 | { |
| 100 | spin_lock(&lockres->l_lock); |
| 101 | lockres->l_flags &= ~USER_LOCK_BUSY; |
| 102 | spin_unlock(&lockres->l_lock); |
| 103 | } |
| 104 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 105 | #define user_log_dlm_error(_func, _stat, _lockres) do { \ |
| 106 | mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on " \ |
| 107 | "resource %.*s: %s\n", dlm_errname(_stat), _func, \ |
| 108 | _lockres->l_namelen, _lockres->l_name, dlm_errmsg(_stat)); \ |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 109 | } while (0) |
| 110 | |
| 111 | /* WARNING: This function lives in a world where the only three lock |
| 112 | * levels are EX, PR, and NL. It *will* have to be adjusted when more |
| 113 | * lock types are added. */ |
| 114 | static inline int user_highest_compat_lock_level(int level) |
| 115 | { |
| 116 | int new_level = LKM_EXMODE; |
| 117 | |
| 118 | if (level == LKM_EXMODE) |
| 119 | new_level = LKM_NLMODE; |
| 120 | else if (level == LKM_PRMODE) |
| 121 | new_level = LKM_PRMODE; |
| 122 | return new_level; |
| 123 | } |
| 124 | |
| 125 | static void user_ast(void *opaque) |
| 126 | { |
| 127 | struct user_lock_res *lockres = opaque; |
| 128 | struct dlm_lockstatus *lksb; |
| 129 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 130 | mlog(0, "AST fired for lockres %.*s\n", lockres->l_namelen, |
| 131 | lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 132 | |
| 133 | spin_lock(&lockres->l_lock); |
| 134 | |
| 135 | lksb = &(lockres->l_lksb); |
| 136 | if (lksb->status != DLM_NORMAL) { |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 137 | mlog(ML_ERROR, "lksb status value of %u on lockres %.*s\n", |
| 138 | lksb->status, lockres->l_namelen, lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 139 | spin_unlock(&lockres->l_lock); |
| 140 | return; |
| 141 | } |
| 142 | |
Mark Fasheh | cc6eb72 | 2006-03-29 10:34:21 -0800 | [diff] [blame] | 143 | mlog_bug_on_msg(lockres->l_requested == LKM_IVMODE, |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 144 | "Lockres %.*s, requested ivmode. flags 0x%x\n", |
| 145 | lockres->l_namelen, lockres->l_name, lockres->l_flags); |
Mark Fasheh | cc6eb72 | 2006-03-29 10:34:21 -0800 | [diff] [blame] | 146 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 147 | /* we're downconverting. */ |
| 148 | if (lockres->l_requested < lockres->l_level) { |
| 149 | if (lockres->l_requested <= |
| 150 | user_highest_compat_lock_level(lockres->l_blocking)) { |
| 151 | lockres->l_blocking = LKM_NLMODE; |
| 152 | lockres->l_flags &= ~USER_LOCK_BLOCKED; |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | lockres->l_level = lockres->l_requested; |
| 157 | lockres->l_requested = LKM_IVMODE; |
| 158 | lockres->l_flags |= USER_LOCK_ATTACHED; |
| 159 | lockres->l_flags &= ~USER_LOCK_BUSY; |
| 160 | |
| 161 | spin_unlock(&lockres->l_lock); |
| 162 | |
| 163 | wake_up(&lockres->l_event); |
| 164 | } |
| 165 | |
| 166 | static inline void user_dlm_grab_inode_ref(struct user_lock_res *lockres) |
| 167 | { |
| 168 | struct inode *inode; |
| 169 | inode = user_dlm_inode_from_user_lockres(lockres); |
| 170 | if (!igrab(inode)) |
| 171 | BUG(); |
| 172 | } |
| 173 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 174 | static void user_dlm_unblock_lock(struct work_struct *work); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 175 | |
| 176 | static void __user_dlm_queue_lockres(struct user_lock_res *lockres) |
| 177 | { |
| 178 | if (!(lockres->l_flags & USER_LOCK_QUEUED)) { |
| 179 | user_dlm_grab_inode_ref(lockres); |
| 180 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 181 | INIT_WORK(&lockres->l_work, user_dlm_unblock_lock); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 182 | |
| 183 | queue_work(user_dlm_worker, &lockres->l_work); |
| 184 | lockres->l_flags |= USER_LOCK_QUEUED; |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | static void __user_dlm_cond_queue_lockres(struct user_lock_res *lockres) |
| 189 | { |
| 190 | int queue = 0; |
| 191 | |
| 192 | if (!(lockres->l_flags & USER_LOCK_BLOCKED)) |
| 193 | return; |
| 194 | |
| 195 | switch (lockres->l_blocking) { |
| 196 | case LKM_EXMODE: |
| 197 | if (!lockres->l_ex_holders && !lockres->l_ro_holders) |
| 198 | queue = 1; |
| 199 | break; |
| 200 | case LKM_PRMODE: |
| 201 | if (!lockres->l_ex_holders) |
| 202 | queue = 1; |
| 203 | break; |
| 204 | default: |
| 205 | BUG(); |
| 206 | } |
| 207 | |
| 208 | if (queue) |
| 209 | __user_dlm_queue_lockres(lockres); |
| 210 | } |
| 211 | |
| 212 | static void user_bast(void *opaque, int level) |
| 213 | { |
| 214 | struct user_lock_res *lockres = opaque; |
| 215 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 216 | mlog(0, "Blocking AST fired for lockres %.*s. Blocking level %d\n", |
| 217 | lockres->l_namelen, lockres->l_name, level); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 218 | |
| 219 | spin_lock(&lockres->l_lock); |
| 220 | lockres->l_flags |= USER_LOCK_BLOCKED; |
| 221 | if (level > lockres->l_blocking) |
| 222 | lockres->l_blocking = level; |
| 223 | |
| 224 | __user_dlm_queue_lockres(lockres); |
| 225 | spin_unlock(&lockres->l_lock); |
| 226 | |
| 227 | wake_up(&lockres->l_event); |
| 228 | } |
| 229 | |
| 230 | static void user_unlock_ast(void *opaque, enum dlm_status status) |
| 231 | { |
| 232 | struct user_lock_res *lockres = opaque; |
| 233 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 234 | mlog(0, "UNLOCK AST called on lock %.*s\n", lockres->l_namelen, |
| 235 | lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 236 | |
Mark Fasheh | f43e691 | 2006-03-29 18:24:12 -0800 | [diff] [blame] | 237 | if (status != DLM_NORMAL && status != DLM_CANCELGRANT) |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 238 | mlog(ML_ERROR, "Dlm returns status %d\n", status); |
| 239 | |
| 240 | spin_lock(&lockres->l_lock); |
Mark Fasheh | 2cd9888 | 2006-03-29 16:49:13 -0800 | [diff] [blame] | 241 | /* The teardown flag gets set early during the unlock process, |
| 242 | * so test the cancel flag to make sure that this ast isn't |
| 243 | * for a concurrent cancel. */ |
| 244 | if (lockres->l_flags & USER_LOCK_IN_TEARDOWN |
| 245 | && !(lockres->l_flags & USER_LOCK_IN_CANCEL)) { |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 246 | lockres->l_level = LKM_IVMODE; |
Mark Fasheh | 2cd9888 | 2006-03-29 16:49:13 -0800 | [diff] [blame] | 247 | } else if (status == DLM_CANCELGRANT) { |
Mark Fasheh | f43e691 | 2006-03-29 18:24:12 -0800 | [diff] [blame] | 248 | /* We tried to cancel a convert request, but it was |
| 249 | * already granted. Don't clear the busy flag - the |
| 250 | * ast should've done this already. */ |
| 251 | BUG_ON(!(lockres->l_flags & USER_LOCK_IN_CANCEL)); |
| 252 | lockres->l_flags &= ~USER_LOCK_IN_CANCEL; |
| 253 | goto out_noclear; |
| 254 | } else { |
| 255 | BUG_ON(!(lockres->l_flags & USER_LOCK_IN_CANCEL)); |
| 256 | /* Cancel succeeded, we want to re-queue */ |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 257 | lockres->l_requested = LKM_IVMODE; /* cancel an |
| 258 | * upconvert |
| 259 | * request. */ |
| 260 | lockres->l_flags &= ~USER_LOCK_IN_CANCEL; |
| 261 | /* we want the unblock thread to look at it again |
| 262 | * now. */ |
Mark Fasheh | f43e691 | 2006-03-29 18:24:12 -0800 | [diff] [blame] | 263 | if (lockres->l_flags & USER_LOCK_BLOCKED) |
| 264 | __user_dlm_queue_lockres(lockres); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 265 | } |
| 266 | |
| 267 | lockres->l_flags &= ~USER_LOCK_BUSY; |
Mark Fasheh | f43e691 | 2006-03-29 18:24:12 -0800 | [diff] [blame] | 268 | out_noclear: |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 269 | spin_unlock(&lockres->l_lock); |
| 270 | |
| 271 | wake_up(&lockres->l_event); |
| 272 | } |
| 273 | |
| 274 | static inline void user_dlm_drop_inode_ref(struct user_lock_res *lockres) |
| 275 | { |
| 276 | struct inode *inode; |
| 277 | inode = user_dlm_inode_from_user_lockres(lockres); |
| 278 | iput(inode); |
| 279 | } |
| 280 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 281 | static void user_dlm_unblock_lock(struct work_struct *work) |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 282 | { |
| 283 | int new_level, status; |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 284 | struct user_lock_res *lockres = |
| 285 | container_of(work, struct user_lock_res, l_work); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 286 | struct dlm_ctxt *dlm = dlm_ctxt_from_user_lockres(lockres); |
| 287 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 288 | mlog(0, "processing lockres %.*s\n", lockres->l_namelen, |
| 289 | lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 290 | |
| 291 | spin_lock(&lockres->l_lock); |
| 292 | |
Mark Fasheh | 1f7bc82 | 2006-03-29 10:33:35 -0800 | [diff] [blame] | 293 | mlog_bug_on_msg(!(lockres->l_flags & USER_LOCK_QUEUED), |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 294 | "Lockres %.*s, flags 0x%x\n", |
| 295 | lockres->l_namelen, lockres->l_name, lockres->l_flags); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 296 | |
Mark Fasheh | 1f7bc82 | 2006-03-29 10:33:35 -0800 | [diff] [blame] | 297 | /* notice that we don't clear USER_LOCK_BLOCKED here. If it's |
| 298 | * set, we want user_ast clear it. */ |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 299 | lockres->l_flags &= ~USER_LOCK_QUEUED; |
| 300 | |
Mark Fasheh | 1f7bc82 | 2006-03-29 10:33:35 -0800 | [diff] [blame] | 301 | /* It's valid to get here and no longer be blocked - if we get |
| 302 | * several basts in a row, we might be queued by the first |
| 303 | * one, the unblock thread might run and clear the queued |
| 304 | * flag, and finally we might get another bast which re-queues |
| 305 | * us before our ast for the downconvert is called. */ |
| 306 | if (!(lockres->l_flags & USER_LOCK_BLOCKED)) { |
Mark Fasheh | 1f7bc82 | 2006-03-29 10:33:35 -0800 | [diff] [blame] | 307 | spin_unlock(&lockres->l_lock); |
| 308 | goto drop_ref; |
| 309 | } |
| 310 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 311 | if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) { |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 312 | spin_unlock(&lockres->l_lock); |
| 313 | goto drop_ref; |
| 314 | } |
| 315 | |
| 316 | if (lockres->l_flags & USER_LOCK_BUSY) { |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 317 | if (lockres->l_flags & USER_LOCK_IN_CANCEL) { |
| 318 | spin_unlock(&lockres->l_lock); |
| 319 | goto drop_ref; |
| 320 | } |
| 321 | |
| 322 | lockres->l_flags |= USER_LOCK_IN_CANCEL; |
| 323 | spin_unlock(&lockres->l_lock); |
| 324 | |
| 325 | status = dlmunlock(dlm, |
| 326 | &lockres->l_lksb, |
| 327 | LKM_CANCEL, |
| 328 | user_unlock_ast, |
| 329 | lockres); |
Mark Fasheh | f43e691 | 2006-03-29 18:24:12 -0800 | [diff] [blame] | 330 | if (status != DLM_NORMAL) |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 331 | user_log_dlm_error("dlmunlock", status, lockres); |
| 332 | goto drop_ref; |
| 333 | } |
| 334 | |
| 335 | /* If there are still incompat holders, we can exit safely |
| 336 | * without worrying about re-queueing this lock as that will |
| 337 | * happen on the last call to user_cluster_unlock. */ |
| 338 | if ((lockres->l_blocking == LKM_EXMODE) |
| 339 | && (lockres->l_ex_holders || lockres->l_ro_holders)) { |
| 340 | spin_unlock(&lockres->l_lock); |
| 341 | mlog(0, "can't downconvert for ex: ro = %u, ex = %u\n", |
| 342 | lockres->l_ro_holders, lockres->l_ex_holders); |
| 343 | goto drop_ref; |
| 344 | } |
| 345 | |
| 346 | if ((lockres->l_blocking == LKM_PRMODE) |
| 347 | && lockres->l_ex_holders) { |
| 348 | spin_unlock(&lockres->l_lock); |
| 349 | mlog(0, "can't downconvert for pr: ex = %u\n", |
| 350 | lockres->l_ex_holders); |
| 351 | goto drop_ref; |
| 352 | } |
| 353 | |
| 354 | /* yay, we can downconvert now. */ |
| 355 | new_level = user_highest_compat_lock_level(lockres->l_blocking); |
| 356 | lockres->l_requested = new_level; |
| 357 | lockres->l_flags |= USER_LOCK_BUSY; |
| 358 | mlog(0, "Downconvert lock from %d to %d\n", |
| 359 | lockres->l_level, new_level); |
| 360 | spin_unlock(&lockres->l_lock); |
| 361 | |
| 362 | /* need lock downconvert request now... */ |
| 363 | status = dlmlock(dlm, |
| 364 | new_level, |
| 365 | &lockres->l_lksb, |
| 366 | LKM_CONVERT|LKM_VALBLK, |
| 367 | lockres->l_name, |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 368 | lockres->l_namelen, |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 369 | user_ast, |
| 370 | lockres, |
| 371 | user_bast); |
| 372 | if (status != DLM_NORMAL) { |
| 373 | user_log_dlm_error("dlmlock", status, lockres); |
| 374 | user_recover_from_dlm_error(lockres); |
| 375 | } |
| 376 | |
| 377 | drop_ref: |
| 378 | user_dlm_drop_inode_ref(lockres); |
| 379 | } |
| 380 | |
| 381 | static inline void user_dlm_inc_holders(struct user_lock_res *lockres, |
| 382 | int level) |
| 383 | { |
| 384 | switch(level) { |
| 385 | case LKM_EXMODE: |
| 386 | lockres->l_ex_holders++; |
| 387 | break; |
| 388 | case LKM_PRMODE: |
| 389 | lockres->l_ro_holders++; |
| 390 | break; |
| 391 | default: |
| 392 | BUG(); |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | /* predict what lock level we'll be dropping down to on behalf |
| 397 | * of another node, and return true if the currently wanted |
| 398 | * level will be compatible with it. */ |
| 399 | static inline int |
| 400 | user_may_continue_on_blocked_lock(struct user_lock_res *lockres, |
| 401 | int wanted) |
| 402 | { |
| 403 | BUG_ON(!(lockres->l_flags & USER_LOCK_BLOCKED)); |
| 404 | |
| 405 | return wanted <= user_highest_compat_lock_level(lockres->l_blocking); |
| 406 | } |
| 407 | |
| 408 | int user_dlm_cluster_lock(struct user_lock_res *lockres, |
| 409 | int level, |
| 410 | int lkm_flags) |
| 411 | { |
| 412 | int status, local_flags; |
| 413 | struct dlm_ctxt *dlm = dlm_ctxt_from_user_lockres(lockres); |
| 414 | |
| 415 | if (level != LKM_EXMODE && |
| 416 | level != LKM_PRMODE) { |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 417 | mlog(ML_ERROR, "lockres %.*s: invalid request!\n", |
| 418 | lockres->l_namelen, lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 419 | status = -EINVAL; |
| 420 | goto bail; |
| 421 | } |
| 422 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 423 | mlog(0, "lockres %.*s: asking for %s lock, passed flags = 0x%x\n", |
| 424 | lockres->l_namelen, lockres->l_name, |
| 425 | (level == LKM_EXMODE) ? "LKM_EXMODE" : "LKM_PRMODE", |
| 426 | lkm_flags); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 427 | |
| 428 | again: |
| 429 | if (signal_pending(current)) { |
| 430 | status = -ERESTARTSYS; |
| 431 | goto bail; |
| 432 | } |
| 433 | |
| 434 | spin_lock(&lockres->l_lock); |
| 435 | |
| 436 | /* We only compare against the currently granted level |
| 437 | * here. If the lock is blocked waiting on a downconvert, |
| 438 | * we'll get caught below. */ |
| 439 | if ((lockres->l_flags & USER_LOCK_BUSY) && |
| 440 | (level > lockres->l_level)) { |
| 441 | /* is someone sitting in dlm_lock? If so, wait on |
| 442 | * them. */ |
| 443 | spin_unlock(&lockres->l_lock); |
| 444 | |
| 445 | user_wait_on_busy_lock(lockres); |
| 446 | goto again; |
| 447 | } |
| 448 | |
| 449 | if ((lockres->l_flags & USER_LOCK_BLOCKED) && |
| 450 | (!user_may_continue_on_blocked_lock(lockres, level))) { |
| 451 | /* is the lock is currently blocked on behalf of |
| 452 | * another node */ |
| 453 | spin_unlock(&lockres->l_lock); |
| 454 | |
| 455 | user_wait_on_blocked_lock(lockres); |
| 456 | goto again; |
| 457 | } |
| 458 | |
| 459 | if (level > lockres->l_level) { |
| 460 | local_flags = lkm_flags | LKM_VALBLK; |
| 461 | if (lockres->l_level != LKM_IVMODE) |
| 462 | local_flags |= LKM_CONVERT; |
| 463 | |
| 464 | lockres->l_requested = level; |
| 465 | lockres->l_flags |= USER_LOCK_BUSY; |
| 466 | spin_unlock(&lockres->l_lock); |
| 467 | |
| 468 | BUG_ON(level == LKM_IVMODE); |
| 469 | BUG_ON(level == LKM_NLMODE); |
| 470 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 471 | /* call dlm_lock to upgrade lock now */ |
| 472 | status = dlmlock(dlm, |
| 473 | level, |
| 474 | &lockres->l_lksb, |
| 475 | local_flags, |
| 476 | lockres->l_name, |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 477 | lockres->l_namelen, |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 478 | user_ast, |
| 479 | lockres, |
| 480 | user_bast); |
| 481 | if (status != DLM_NORMAL) { |
| 482 | if ((lkm_flags & LKM_NOQUEUE) && |
| 483 | (status == DLM_NOTQUEUED)) |
| 484 | status = -EAGAIN; |
| 485 | else { |
| 486 | user_log_dlm_error("dlmlock", status, lockres); |
| 487 | status = -EINVAL; |
| 488 | } |
| 489 | user_recover_from_dlm_error(lockres); |
| 490 | goto bail; |
| 491 | } |
| 492 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 493 | user_wait_on_busy_lock(lockres); |
| 494 | goto again; |
| 495 | } |
| 496 | |
| 497 | user_dlm_inc_holders(lockres, level); |
| 498 | spin_unlock(&lockres->l_lock); |
| 499 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 500 | status = 0; |
| 501 | bail: |
| 502 | return status; |
| 503 | } |
| 504 | |
| 505 | static inline void user_dlm_dec_holders(struct user_lock_res *lockres, |
| 506 | int level) |
| 507 | { |
| 508 | switch(level) { |
| 509 | case LKM_EXMODE: |
| 510 | BUG_ON(!lockres->l_ex_holders); |
| 511 | lockres->l_ex_holders--; |
| 512 | break; |
| 513 | case LKM_PRMODE: |
| 514 | BUG_ON(!lockres->l_ro_holders); |
| 515 | lockres->l_ro_holders--; |
| 516 | break; |
| 517 | default: |
| 518 | BUG(); |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | void user_dlm_cluster_unlock(struct user_lock_res *lockres, |
| 523 | int level) |
| 524 | { |
| 525 | if (level != LKM_EXMODE && |
| 526 | level != LKM_PRMODE) { |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 527 | mlog(ML_ERROR, "lockres %.*s: invalid request!\n", |
| 528 | lockres->l_namelen, lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 529 | return; |
| 530 | } |
| 531 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 532 | spin_lock(&lockres->l_lock); |
| 533 | user_dlm_dec_holders(lockres, level); |
| 534 | __user_dlm_cond_queue_lockres(lockres); |
| 535 | spin_unlock(&lockres->l_lock); |
| 536 | } |
| 537 | |
| 538 | void user_dlm_write_lvb(struct inode *inode, |
| 539 | const char *val, |
| 540 | unsigned int len) |
| 541 | { |
| 542 | struct user_lock_res *lockres = &DLMFS_I(inode)->ip_lockres; |
| 543 | char *lvb = lockres->l_lksb.lvb; |
| 544 | |
| 545 | BUG_ON(len > DLM_LVB_LEN); |
| 546 | |
| 547 | spin_lock(&lockres->l_lock); |
| 548 | |
| 549 | BUG_ON(lockres->l_level < LKM_EXMODE); |
| 550 | memcpy(lvb, val, len); |
| 551 | |
| 552 | spin_unlock(&lockres->l_lock); |
| 553 | } |
| 554 | |
| 555 | void user_dlm_read_lvb(struct inode *inode, |
| 556 | char *val, |
| 557 | unsigned int len) |
| 558 | { |
| 559 | struct user_lock_res *lockres = &DLMFS_I(inode)->ip_lockres; |
| 560 | char *lvb = lockres->l_lksb.lvb; |
| 561 | |
| 562 | BUG_ON(len > DLM_LVB_LEN); |
| 563 | |
| 564 | spin_lock(&lockres->l_lock); |
| 565 | |
| 566 | BUG_ON(lockres->l_level < LKM_PRMODE); |
| 567 | memcpy(val, lvb, len); |
| 568 | |
| 569 | spin_unlock(&lockres->l_lock); |
| 570 | } |
| 571 | |
| 572 | void user_dlm_lock_res_init(struct user_lock_res *lockres, |
| 573 | struct dentry *dentry) |
| 574 | { |
| 575 | memset(lockres, 0, sizeof(*lockres)); |
| 576 | |
| 577 | spin_lock_init(&lockres->l_lock); |
| 578 | init_waitqueue_head(&lockres->l_event); |
| 579 | lockres->l_level = LKM_IVMODE; |
| 580 | lockres->l_requested = LKM_IVMODE; |
| 581 | lockres->l_blocking = LKM_IVMODE; |
| 582 | |
| 583 | /* should have been checked before getting here. */ |
| 584 | BUG_ON(dentry->d_name.len >= USER_DLM_LOCK_ID_MAX_LEN); |
| 585 | |
| 586 | memcpy(lockres->l_name, |
| 587 | dentry->d_name.name, |
| 588 | dentry->d_name.len); |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 589 | lockres->l_namelen = dentry->d_name.len; |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 590 | } |
| 591 | |
| 592 | int user_dlm_destroy_lock(struct user_lock_res *lockres) |
| 593 | { |
| 594 | int status = -EBUSY; |
| 595 | struct dlm_ctxt *dlm = dlm_ctxt_from_user_lockres(lockres); |
| 596 | |
Mark Fasheh | ea5b3a1 | 2006-09-08 11:39:27 -0700 | [diff] [blame] | 597 | mlog(0, "asked to destroy %.*s\n", lockres->l_namelen, lockres->l_name); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 598 | |
| 599 | spin_lock(&lockres->l_lock); |
Mark Fasheh | 2cd9888 | 2006-03-29 16:49:13 -0800 | [diff] [blame] | 600 | if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) { |
Mark Fasheh | 2cd9888 | 2006-03-29 16:49:13 -0800 | [diff] [blame] | 601 | spin_unlock(&lockres->l_lock); |
| 602 | return 0; |
| 603 | } |
| 604 | |
| 605 | lockres->l_flags |= USER_LOCK_IN_TEARDOWN; |
| 606 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 607 | while (lockres->l_flags & USER_LOCK_BUSY) { |
| 608 | spin_unlock(&lockres->l_lock); |
| 609 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 610 | user_wait_on_busy_lock(lockres); |
| 611 | |
| 612 | spin_lock(&lockres->l_lock); |
| 613 | } |
| 614 | |
| 615 | if (lockres->l_ro_holders || lockres->l_ex_holders) { |
| 616 | spin_unlock(&lockres->l_lock); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 617 | goto bail; |
| 618 | } |
| 619 | |
| 620 | status = 0; |
| 621 | if (!(lockres->l_flags & USER_LOCK_ATTACHED)) { |
| 622 | spin_unlock(&lockres->l_lock); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 623 | goto bail; |
| 624 | } |
| 625 | |
| 626 | lockres->l_flags &= ~USER_LOCK_ATTACHED; |
| 627 | lockres->l_flags |= USER_LOCK_BUSY; |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 628 | spin_unlock(&lockres->l_lock); |
| 629 | |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 630 | status = dlmunlock(dlm, |
| 631 | &lockres->l_lksb, |
| 632 | LKM_VALBLK, |
| 633 | user_unlock_ast, |
| 634 | lockres); |
| 635 | if (status != DLM_NORMAL) { |
| 636 | user_log_dlm_error("dlmunlock", status, lockres); |
| 637 | status = -EINVAL; |
| 638 | goto bail; |
| 639 | } |
| 640 | |
| 641 | user_wait_on_busy_lock(lockres); |
| 642 | |
| 643 | status = 0; |
| 644 | bail: |
| 645 | return status; |
| 646 | } |
| 647 | |
Joel Becker | d24fbcd | 2008-01-25 17:02:21 -0800 | [diff] [blame] | 648 | struct dlm_ctxt *user_dlm_register_context(struct qstr *name, |
| 649 | struct dlm_protocol_version *proto) |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 650 | { |
| 651 | struct dlm_ctxt *dlm; |
| 652 | u32 dlm_key; |
| 653 | char *domain; |
| 654 | |
Kurt Hackel | ad8100e | 2006-05-01 14:25:21 -0700 | [diff] [blame] | 655 | domain = kmalloc(name->len + 1, GFP_NOFS); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 656 | if (!domain) { |
| 657 | mlog_errno(-ENOMEM); |
| 658 | return ERR_PTR(-ENOMEM); |
| 659 | } |
| 660 | |
| 661 | dlm_key = crc32_le(0, name->name, name->len); |
| 662 | |
| 663 | snprintf(domain, name->len + 1, "%.*s", name->len, name->name); |
| 664 | |
Joel Becker | d24fbcd | 2008-01-25 17:02:21 -0800 | [diff] [blame] | 665 | dlm = dlm_register_domain(domain, dlm_key, proto); |
Mark Fasheh | 8df08c8 | 2005-12-15 14:31:23 -0800 | [diff] [blame] | 666 | if (IS_ERR(dlm)) |
| 667 | mlog_errno(PTR_ERR(dlm)); |
| 668 | |
| 669 | kfree(domain); |
| 670 | return dlm; |
| 671 | } |
| 672 | |
| 673 | void user_dlm_unregister_context(struct dlm_ctxt *dlm) |
| 674 | { |
| 675 | dlm_unregister_domain(dlm); |
| 676 | } |