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| True | False | - | Line | Source |
| 1 | /* | |||
| 2 | * linux/fs/lockd/clntlock.c | |||
| 3 | * | |||
| 4 | * Lock handling for the client side NLM implementation | |||
| 5 | * | |||
| 6 | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> | |||
| 7 | */ | |||
| 8 | ||||
| 9 | #include <linux/module.h> | |||
| 10 | #include <linux/types.h> | |||
| 11 | #include <linux/time.h> | |||
| 12 | #include <linux/nfs_fs.h> | |||
| 13 | #include <linux/sunrpc/clnt.h> | |||
| 14 | #include <linux/sunrpc/svc.h> | |||
| 15 | #include <linux/lockd/lockd.h> | |||
| 16 | #include <linux/smp_lock.h> | |||
| 17 | ||||
| 18 | #define NLMDBG_FACILITY NLMDBG_CLIENT | |||
| 19 | ||||
| 20 | /* | |||
| 21 | * Local function prototypes | |||
| 22 | */ | |||
| 23 | static int reclaimer(void *ptr); | |||
| 24 | ||||
| 25 | /* | |||
| 26 | * The following functions handle blocking and granting from the | |||
| 27 | * client perspective. | |||
| 28 | */ | |||
| 29 | ||||
| 30 | /* | |||
| 31 | * This is the representation of a blocked client lock. | |||
| 32 | */ | |||
| 33 | struct nlm_wait { | |||
| 34 | struct list_head b_list; /* linked list */ | |||
| 35 | wait_queue_head_t b_wait; /* where to wait on */ | |||
| 36 | struct nlm_host * b_host; | |||
| 37 | struct file_lock * b_lock; /* local file lock */ | |||
| 38 | unsigned short b_reclaim; /* got to reclaim lock */ | |||
| 39 | u32 b_status; /* grant callback status */ | |||
| 40 | }; | |||
| 41 | ||||
| 42 | static LIST_HEAD(nlm_blocked); | |||
| 43 | ||||
| 44 | /* | |||
| 45 | * Queue up a lock for blocking so that the GRANTED request can see it | |||
| 46 | */ | |||
| 0 | 0 | - | 47 | int nlmclnt_prepare_block(struct nlm_rqst *req, struct nlm_host *host, struct file_lock *fl) |
| 48 | { | |||
| 49 | struct nlm_wait *block; | |||
| 50 | ||||
| 51 | BUG_ON(req->a_block != NULL); | |||
| 0 | 0 | - | 51 | if (__builtin_expect ( ! ! ( ( req -> a_bloc.. |
| 0 | 0 | - | 51 | do-while (0) |
| 52 | block = kmalloc(sizeof(*block), GFP_KERNEL); | |||
| 0 | 0 | - | 53 | if (block == NULL) |
| 0 | - | 54 | return -ENOMEM; | |
| 55 | block->b_host = host; | |||
| 56 | block->b_lock = fl; | |||
| 57 | init_waitqueue_head(&block->b_wait); | |||
| 58 | block->b_status = NLM_LCK_BLOCKED; | |||
| 59 | ||||
| 60 | list_add(&block->b_list, &nlm_blocked); | |||
| 61 | req->a_block = block; | |||
| 62 | ||||
| 0 | - | 63 | return 0; | |
| 64 | } | |||
| 65 | ||||
| 0 | 0 | - | 66 | void nlmclnt_finish_block(struct nlm_rqst *req) |
| 67 | { | |||
| 68 | struct nlm_wait *block = req->a_block; | |||
| 69 | ||||
| 0 | 0 | - | 70 | if (block == NULL) |
| 0 | - | 71 | return; | |
| 72 | req->a_block = NULL; | |||
| 73 | list_del(&block->b_list); | |||
| 74 | kfree(block); | |||
| 75 | } | |||
| 76 | ||||
| 77 | /* | |||
| 78 | * Block on a lock | |||
| 79 | */ | |||
| 0 | 0 | - | 80 | long nlmclnt_block(struct nlm_rqst *req, long timeout) |
| 81 | { | |||
| 82 | struct nlm_wait *block = req->a_block; | |||
| 83 | long ret; | |||
| 84 | ||||
| 85 | /* A borken server might ask us to block even if we didn't | |||
| 86 | * request it. Just say no! | |||
| 87 | */ | |||
| 0 | 0 | - | 88 | if (!req->a_args.block) |
| 0 | - | 89 | return -EAGAIN; | |
| 90 | ||||
| 91 | /* Go to sleep waiting for GRANT callback. Some servers seem | |||
| 92 | * to lose callbacks, however, so we're going to poll from | |||
| 93 | * time to time just to make sure. | |||
| 94 | * | |||
| 95 | * For now, the retry frequency is pretty high; normally | |||
| 96 | * a 1 minute timeout would do. See the comment before | |||
| 97 | * nlmclnt_lock for an explanation. | |||
| 98 | */ | |||
| 99 | ret = wait_event_interruptible_timeout(block->b_wait, | |||
| 100 | block->b_status != NLM_LCK_BLOCKED, | |||
| 101 | timeout); | |||
| 102 | ||||
| 0 | 0 | - | 103 | if (block->b_status != NLM_LCK_BLOCKED) { |
| 104 | req->a_res.status = block->b_status; | |||
| 105 | block->b_status = NLM_LCK_BLOCKED; | |||
| 106 | } | |||
| 107 | ||||
| 0 | - | 108 | return ret; | |
| 109 | } | |||
| 110 | ||||
| 111 | /* | |||
| 112 | * The server lockd has called us back to tell us the lock was granted | |||
| 113 | */ | |||
| 0 | 0 | - | 114 | u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock) |
| 115 | { | |||
| 116 | const struct file_lock *fl = &lock->fl; | |||
| 117 | const struct nfs_fh *fh = &lock->fh; | |||
| 118 | struct nlm_wait *block; | |||
| 119 | u32 res = nlm_lck_denied; | |||
| 120 | ||||
| 121 | /* | |||
| 122 | * Look up blocked request based on arguments. | |||
| 123 | * Warning: must not use cookie to match it! | |||
| 124 | */ | |||
| 0 | 0 | - | 125 | list_for_each_entry(block, &nlm_blocked, b_list) { |
| 126 | struct file_lock *fl_blocked = block->b_lock; | |||
| 127 | ||||
| 0 | 0 | - | 128 | if (!nlm_compare_locks(fl_blocked, fl)) |
| 0 | - | 129 | continue; | |
| 0 | 0 | - | 130 | if (!nlm_cmp_addr(&block->b_host->h_addr, addr)) |
| 0 | - | 131 | continue; | |
| 0 | 0 | - | 132 | if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_dentry->d_inode) ,fh) != 0) |
| 0 | - | 133 | continue; | |
| 134 | /* Alright, we found a lock. Set the return status | |||
| 135 | * and wake up the caller | |||
| 136 | */ | |||
| 137 | block->b_status = NLM_LCK_GRANTED; | |||
| 138 | wake_up(&block->b_wait); | |||
| 139 | res = nlm_granted; | |||
| 140 | } | |||
| 0 | - | 141 | return res; | |
| 142 | } | |||
| 143 | ||||
| 144 | /* | |||
| 145 | * The following procedures deal with the recovery of locks after a | |||
| 146 | * server crash. | |||
| 147 | */ | |||
| 148 | ||||
| 149 | /* | |||
| 150 | * Mark the locks for reclaiming. | |||
| 151 | * FIXME: In 2.5 we don't want to iterate through any global file_lock_list. | |||
| 152 | * Maintain NLM lock reclaiming lists in the nlm_host instead. | |||
| 153 | */ | |||
| 154 | static | |||
| 0 | 0 | - | 155 | void nlmclnt_mark_reclaim(struct nlm_host *host) |
| 156 | { | |||
| 157 | struct file_lock *fl; | |||
| 158 | struct inode *inode; | |||
| 159 | struct list_head *tmp; | |||
| 160 | ||||
| 0 | 0 | - | 161 | list_for_each(tmp, &file_lock_list) { |
| 162 | fl = list_entry(tmp, struct file_lock, fl_link); | |||
| 163 | ||||
| 164 | inode = fl->fl_file->f_dentry->d_inode; | |||
| 0 | 0 | - | 165 | if (inode->i_sb->s_magic != NFS_SUPER_MAGIC) |
| 0 | - | 166 | continue; | |
| 0 | 0 | - | 167 | if (fl->fl_u.nfs_fl.owner == NULL) |
| 0 | - | 168 | continue; | |
| 0 | 0 | - | 169 | if (fl->fl_u.nfs_fl.owner->host != host) |
| 0 | - | 170 | continue; | |
| 0 | 0 | - | 171 | if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED)) |
| 0 | - | 172 | continue; | |
| 173 | fl->fl_u.nfs_fl.flags |= NFS_LCK_RECLAIM; | |||
| 174 | } | |||
| 175 | } | |||
| 176 | ||||
| 177 | /* | |||
| 178 | * Someone has sent us an SM_NOTIFY. Ensure we bind to the new port number, | |||
| 179 | * that we mark locks for reclaiming, and that we bump the pseudo NSM state. | |||
| 180 | */ | |||
| 181 | static inline | |||
| 0 | 0 | - | 182 | void nlmclnt_prepare_reclaim(struct nlm_host *host, u32 newstate) |
| 183 | { | |||
| 184 | host->h_monitored = 0; | |||
| 185 | host->h_nsmstate = newstate; | |||
| 186 | host->h_state++; | |||
| 187 | host->h_nextrebind = 0; | |||
| 188 | nlm_rebind_host(host); | |||
| 189 | nlmclnt_mark_reclaim(host); | |||
| 190 | dprintk("NLM: reclaiming locks for host %s", host->h_name); | |||
| 0 | 0 | - | 190 | if (__builtin_expect ( ! ! ( nlm_debug & 0x0.. |
| 0 | 0 | - | 190 | do-while (0) |
| 191 | } | |||
| 192 | ||||
| 193 | /* | |||
| 194 | * Reclaim all locks on server host. We do this by spawning a separate | |||
| 195 | * reclaimer thread. | |||
| 196 | */ | |||
| 197 | void | |||
| 0 | 0 | - | 198 | nlmclnt_recovery(struct nlm_host *host, u32 newstate) |
| 199 | { | |||
| 0 | 0 | - | 200 | if (host->h_reclaiming++) { |
| 0 | 0 | - | 201 | if (host->h_nsmstate == newstate) |
| 0 | - | 202 | return; | |
| 203 | nlmclnt_prepare_reclaim(host, newstate); | |||
| 204 | } else { | |||
| 205 | nlmclnt_prepare_reclaim(host, newstate); | |||
| 206 | nlm_get_host(host); | |||
| 207 | __module_get(THIS_MODULE); | |||
| 0 | 0 | - | 208 | if (kernel_thread(reclaimer, host, CLONE_KERNEL) < 0) |
| 209 | module_put(THIS_MODULE); | |||
| 210 | } | |||
| 211 | } | |||
| 212 | ||||
| 213 | static int | |||
| 0 | 0 | - | 214 | reclaimer(void *ptr) |
| 215 | { | |||
| 216 | struct nlm_host *host = (struct nlm_host *) ptr; | |||
| 217 | struct nlm_wait *block; | |||
| 218 | struct list_head *tmp; | |||
| 219 | struct file_lock *fl; | |||
| 220 | struct inode *inode; | |||
| 221 | ||||
| 222 | daemonize("%s-reclaim", host->h_name); | |||
| 223 | allow_signal(SIGKILL); | |||
| 224 | ||||
| 225 | /* This one ensures that our parent doesn't terminate while the | |||
| 226 | * reclaim is in progress */ | |||
| 227 | lock_kernel(); | |||
| 0 | 0 | - | 227 | do-while (0) |
| 228 | lockd_up(); | |||
| 229 | ||||
| 230 | /* First, reclaim all locks that have been marked. */ | |||
| 231 | restart: | |||
| 0 | 0 | - | 232 | list_for_each(tmp, &file_lock_list) { |
| 233 | fl = list_entry(tmp, struct file_lock, fl_link); | |||
| 234 | ||||
| 235 | inode = fl->fl_file->f_dentry->d_inode; | |||
| 0 | 0 | - | 236 | if (inode->i_sb->s_magic != NFS_SUPER_MAGIC) |
| 0 | - | 237 | continue; | |
| 0 | 0 | - | 238 | if (fl->fl_u.nfs_fl.owner == NULL) |
| 0 | - | 239 | continue; | |
| 0 | 0 | - | 240 | if (fl->fl_u.nfs_fl.owner->host != host) |
| 0 | - | 241 | continue; | |
| 0 | 0 | - | 242 | if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM)) |
| 0 | - | 243 | continue; | |
| 244 | ||||
| 245 | fl->fl_u.nfs_fl.flags &= ~NFS_LCK_RECLAIM; | |||
| 246 | nlmclnt_reclaim(host, fl); | |||
| 0 | 0 | - | 247 | if (signalled()) |
| 0 | - | 248 | break; | |
| 0 | - | 249 | goto restart; | |
| 250 | } | |||
| 251 | ||||
| 252 | host->h_reclaiming = 0; | |||
| 253 | ||||
| 254 | /* Now, wake up all processes that sleep on a blocked lock */ | |||
| 0 | 0 | - | 255 | list_for_each_entry(block, &nlm_blocked, b_list) { |
| 0 | 0 | - | 256 | if (block->b_host == host) { |
| 257 | block->b_status = NLM_LCK_DENIED_GRACE_PERIOD; | |||
| 258 | wake_up(&block->b_wait); | |||
| 259 | } | |||
| 260 | } | |||
| 261 | ||||
| 262 | /* Release host handle after use */ | |||
| 263 | nlm_release_host(host); | |||
| 264 | lockd_down(); | |||
| 265 | unlock_kernel(); | |||
| 0 | 0 | - | 265 | do-while (0) |
| 266 | module_put_and_exit(0); | |||
| 267 | } | |||
| ***TER 0% (0/88) of SOURCE FILE clntlock.c | ||||