Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 { |
Trond Myklebust | 4f15e2b | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 34 | struct list_head b_list; /* linked list */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 39 | __be32 b_status; /* grant callback status */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | }; |
| 41 | |
Trond Myklebust | 4f15e2b | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 42 | static LIST_HEAD(nlm_blocked); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
Chuck Lever | 52c4044 | 2008-01-11 17:09:44 -0500 | [diff] [blame^] | 44 | /** |
| 45 | * nlmclnt_init - Set up per-NFS mount point lockd data structures |
| 46 | * @server_name: server's hostname |
| 47 | * @server_address: server's network address |
| 48 | * @server_addrlen: length of server's address |
| 49 | * @protocol: transport protocol lockd should use |
| 50 | * @nfs_version: NFS protocol version for this mount point |
| 51 | * |
| 52 | * Returns pointer to an appropriate nlm_host struct, |
| 53 | * or an ERR_PTR value. |
| 54 | */ |
| 55 | struct nlm_host *nlmclnt_init(const char *server_name, |
| 56 | const struct sockaddr *server_address, |
| 57 | size_t server_addrlen, |
| 58 | unsigned short protocol, u32 nfs_version) |
| 59 | { |
| 60 | struct nlm_host *host; |
| 61 | u32 nlm_version = (nfs_version == 2) ? 1 : 4; |
| 62 | int status; |
| 63 | |
| 64 | status = lockd_up(protocol); |
| 65 | if (status < 0) |
| 66 | return ERR_PTR(status); |
| 67 | |
| 68 | host = nlmclnt_lookup_host((struct sockaddr_in *)server_address, |
| 69 | protocol, nlm_version, |
| 70 | server_name, strlen(server_name)); |
| 71 | if (host == NULL) { |
| 72 | lockd_down(); |
| 73 | return ERR_PTR(-ENOLCK); |
| 74 | } |
| 75 | |
| 76 | return host; |
| 77 | } |
| 78 | EXPORT_SYMBOL_GPL(nlmclnt_init); |
| 79 | |
| 80 | /** |
| 81 | * nlmclnt_done - Release resources allocated by nlmclnt_init() |
| 82 | * @host: nlm_host structure reserved by nlmclnt_init() |
| 83 | * |
| 84 | */ |
| 85 | void nlmclnt_done(struct nlm_host *host) |
| 86 | { |
| 87 | nlm_release_host(host); |
| 88 | lockd_down(); |
| 89 | } |
| 90 | EXPORT_SYMBOL_GPL(nlmclnt_done); |
| 91 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | /* |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 93 | * Queue up a lock for blocking so that the GRANTED request can see it |
| 94 | */ |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 95 | struct nlm_wait *nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl) |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 96 | { |
| 97 | struct nlm_wait *block; |
| 98 | |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 99 | block = kmalloc(sizeof(*block), GFP_KERNEL); |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 100 | if (block != NULL) { |
| 101 | block->b_host = host; |
| 102 | block->b_lock = fl; |
| 103 | init_waitqueue_head(&block->b_wait); |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 104 | block->b_status = nlm_lck_blocked; |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 105 | list_add(&block->b_list, &nlm_blocked); |
| 106 | } |
| 107 | return block; |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 108 | } |
| 109 | |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 110 | void nlmclnt_finish_block(struct nlm_wait *block) |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 111 | { |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 112 | if (block == NULL) |
| 113 | return; |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 114 | list_del(&block->b_list); |
| 115 | kfree(block); |
| 116 | } |
| 117 | |
| 118 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | * Block on a lock |
| 120 | */ |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 121 | int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | { |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 123 | long ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 125 | /* A borken server might ask us to block even if we didn't |
| 126 | * request it. Just say no! |
| 127 | */ |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 128 | if (block == NULL) |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 129 | return -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
| 131 | /* Go to sleep waiting for GRANT callback. Some servers seem |
| 132 | * to lose callbacks, however, so we're going to poll from |
| 133 | * time to time just to make sure. |
| 134 | * |
| 135 | * For now, the retry frequency is pretty high; normally |
| 136 | * a 1 minute timeout would do. See the comment before |
| 137 | * nlmclnt_lock for an explanation. |
| 138 | */ |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 139 | ret = wait_event_interruptible_timeout(block->b_wait, |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 140 | block->b_status != nlm_lck_blocked, |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 141 | timeout); |
Trond Myklebust | 3a649b8 | 2006-03-20 13:44:44 -0500 | [diff] [blame] | 142 | if (ret < 0) |
| 143 | return -ERESTARTSYS; |
| 144 | req->a_res.status = block->b_status; |
| 145 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | } |
| 147 | |
| 148 | /* |
| 149 | * The server lockd has called us back to tell us the lock was granted |
| 150 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 151 | __be32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | { |
Trond Myklebust | 5ac5f9d | 2006-02-14 13:53:04 -0800 | [diff] [blame] | 153 | const struct file_lock *fl = &lock->fl; |
| 154 | const struct nfs_fh *fh = &lock->fh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | struct nlm_wait *block; |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 156 | __be32 res = nlm_lck_denied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
| 158 | /* |
| 159 | * Look up blocked request based on arguments. |
| 160 | * Warning: must not use cookie to match it! |
| 161 | */ |
Trond Myklebust | 4f15e2b | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 162 | list_for_each_entry(block, &nlm_blocked, b_list) { |
Trond Myklebust | 5ac5f9d | 2006-02-14 13:53:04 -0800 | [diff] [blame] | 163 | struct file_lock *fl_blocked = block->b_lock; |
| 164 | |
Trond Myklebust | 7bab377 | 2006-03-20 13:44:06 -0500 | [diff] [blame] | 165 | if (fl_blocked->fl_start != fl->fl_start) |
| 166 | continue; |
| 167 | if (fl_blocked->fl_end != fl->fl_end) |
| 168 | continue; |
| 169 | /* |
| 170 | * Careful! The NLM server will return the 32-bit "pid" that |
| 171 | * we put on the wire: in this case the lockowner "pid". |
| 172 | */ |
| 173 | if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid) |
Trond Myklebust | 5ac5f9d | 2006-02-14 13:53:04 -0800 | [diff] [blame] | 174 | continue; |
| 175 | if (!nlm_cmp_addr(&block->b_host->h_addr, addr)) |
| 176 | continue; |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 177 | if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0) |
Trond Myklebust | 5ac5f9d | 2006-02-14 13:53:04 -0800 | [diff] [blame] | 178 | continue; |
| 179 | /* Alright, we found a lock. Set the return status |
| 180 | * and wake up the caller |
| 181 | */ |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 182 | block->b_status = nlm_granted; |
Trond Myklebust | 5ac5f9d | 2006-02-14 13:53:04 -0800 | [diff] [blame] | 183 | wake_up(&block->b_wait); |
| 184 | res = nlm_granted; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } |
Trond Myklebust | ecdbf76 | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 186 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | } |
| 188 | |
| 189 | /* |
| 190 | * The following procedures deal with the recovery of locks after a |
| 191 | * server crash. |
| 192 | */ |
| 193 | |
| 194 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | * Reclaim all locks on server host. We do this by spawning a separate |
| 196 | * reclaimer thread. |
| 197 | */ |
| 198 | void |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 199 | nlmclnt_recovery(struct nlm_host *host) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | { |
Trond Myklebust | 28df955 | 2006-06-09 09:40:27 -0400 | [diff] [blame] | 201 | if (!host->h_reclaiming++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | nlm_get_host(host); |
| 203 | __module_get(THIS_MODULE); |
Oleg Nesterov | 550facd | 2007-05-10 22:55:07 -0700 | [diff] [blame] | 204 | if (kernel_thread(reclaimer, host, CLONE_FS | CLONE_FILES) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | module_put(THIS_MODULE); |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | static int |
| 210 | reclaimer(void *ptr) |
| 211 | { |
| 212 | struct nlm_host *host = (struct nlm_host *) ptr; |
| 213 | struct nlm_wait *block; |
Christoph Hellwig | 26bcbf9 | 2006-03-20 13:44:40 -0500 | [diff] [blame] | 214 | struct file_lock *fl, *next; |
Trond Myklebust | 28df955 | 2006-06-09 09:40:27 -0400 | [diff] [blame] | 215 | u32 nsmstate; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
| 217 | daemonize("%s-reclaim", host->h_name); |
| 218 | allow_signal(SIGKILL); |
| 219 | |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 220 | down_write(&host->h_rwsem); |
| 221 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | /* This one ensures that our parent doesn't terminate while the |
| 223 | * reclaim is in progress */ |
| 224 | lock_kernel(); |
NeilBrown | 4a3ae42 | 2006-10-02 02:17:53 -0700 | [diff] [blame] | 225 | lockd_up(0); /* note: this cannot fail as lockd is already running */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | |
Adrian Bunk | d019bcf | 2007-01-29 13:19:51 -0800 | [diff] [blame] | 227 | dprintk("lockd: reclaiming locks for host %s\n", host->h_name); |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 228 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | restart: |
Trond Myklebust | 28df955 | 2006-06-09 09:40:27 -0400 | [diff] [blame] | 230 | nsmstate = host->h_nsmstate; |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 231 | |
| 232 | /* Force a portmap getport - the peer's lockd will |
| 233 | * most likely end up on a different port. |
| 234 | */ |
Olaf Kirch | 0ade060 | 2006-10-04 02:16:04 -0700 | [diff] [blame] | 235 | host->h_nextrebind = jiffies; |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 236 | nlm_rebind_host(host); |
| 237 | |
| 238 | /* First, reclaim all locks that have been granted. */ |
| 239 | list_splice_init(&host->h_granted, &host->h_reclaim); |
Christoph Hellwig | 26bcbf9 | 2006-03-20 13:44:40 -0500 | [diff] [blame] | 240 | list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) { |
Trond Myklebust | 4c060b5 | 2006-03-20 13:44:41 -0500 | [diff] [blame] | 241 | list_del_init(&fl->fl_u.nfs_fl.list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 243 | /* Why are we leaking memory here? --okir */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | if (signalled()) |
Trond Myklebust | 4c060b5 | 2006-03-20 13:44:41 -0500 | [diff] [blame] | 245 | continue; |
Trond Myklebust | 28df955 | 2006-06-09 09:40:27 -0400 | [diff] [blame] | 246 | if (nlmclnt_reclaim(host, fl) != 0) |
| 247 | continue; |
| 248 | list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted); |
| 249 | if (host->h_nsmstate != nsmstate) { |
| 250 | /* Argh! The server rebooted again! */ |
Trond Myklebust | 28df955 | 2006-06-09 09:40:27 -0400 | [diff] [blame] | 251 | goto restart; |
| 252 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | } |
Olaf Kirch | 5c8dd29 | 2006-10-04 02:15:55 -0700 | [diff] [blame] | 254 | |
| 255 | host->h_reclaiming = 0; |
| 256 | up_write(&host->h_rwsem); |
Adrian Bunk | d019bcf | 2007-01-29 13:19:51 -0800 | [diff] [blame] | 257 | dprintk("NLM: done reclaiming locks for host %s\n", host->h_name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | |
| 259 | /* Now, wake up all processes that sleep on a blocked lock */ |
Trond Myklebust | 4f15e2b | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 260 | list_for_each_entry(block, &nlm_blocked, b_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | if (block->b_host == host) { |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 262 | block->b_status = nlm_lck_denied_grace_period; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | wake_up(&block->b_wait); |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | /* Release host handle after use */ |
| 268 | nlm_release_host(host); |
| 269 | lockd_down(); |
| 270 | unlock_kernel(); |
| 271 | module_put_and_exit(0); |
| 272 | } |