1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (C) 2004, 2005 Cluster File Systems, Inc.
6 * Author: Phil Schwan <phil@clusterfs.com>
7 * Author: Oleg Drokin <green@clusterfs.com>
8 * Author: Yury Umanets <yury@clusterfs.com>
9 * Review: Nikita Danilov <nikita@clusterfs.com>
11 * This file is part of Lustre, http://www.lustre.org.
13 * Lustre is free software; you can redistribute it and/or
14 * modify it under the terms of version 2 of the GNU General Public
15 * License as published by the Free Software Foundation.
17 * Lustre is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with Lustre; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 #define DEBUG_SUBSYSTEM S_LLITE
30 #include <linux/version.h>
31 #include <asm/uaccess.h>
32 #include <linux/file.h>
33 #include <linux/kmod.h>
35 #include <linux/lustre_lite.h>
36 #include "llite_internal.h"
38 static struct list_head gns_sbi_list = LIST_HEAD_INIT(gns_sbi_list);
39 static spinlock_t gns_lock = SPIN_LOCK_UNLOCKED;
40 static struct ptlrpc_thread gns_thread;
41 static struct ll_gns_ctl gns_ctl;
44 * waits until passed dentry gets mountpoint or timeout and attempts are
45 * exhausted. Returns 1 if dentry became mountpoint and 0 otherwise.
48 ll_gns_wait_for_mount(struct dentry *dentry,
49 int timeout, int tries)
51 struct l_wait_info lwi;
52 struct ll_sb_info *sbi;
56 LASSERT(dentry != NULL);
57 LASSERT(!IS_ERR(dentry));
58 sbi = ll_s2sbi(dentry->d_sb);
60 lwi = LWI_TIMEOUT(timeout * HZ, NULL, NULL);
61 for (; !d_mountpoint(dentry) && tries > 0; tries--) {
62 l_wait_event(sbi->ll_gns_waitq, d_mountpoint(dentry), &lwi);
63 if (signal_pending(current))
64 GOTO(out, rc = -EINTR);
67 if (!d_mountpoint(dentry))
72 spin_lock(&sbi->ll_gns_lock);
73 sbi->ll_gns_state = LL_GNS_FINISHED;
74 spin_unlock(&sbi->ll_gns_lock);
79 * tries to mount the mount object under passed @dentry. In the case of success
80 * @dentry will become mount point and 0 will be returned. Error code will be
84 ll_gns_mount_object(struct dentry *dentry, struct vfsmount *mnt)
86 char *path, *pathpage, *datapage, *argv[4];
87 struct file *mntinfo_fd = NULL;
88 int cleanup_phase = 0, rc = 0;
89 struct ll_sb_info *sbi;
90 struct dentry *dchild;
93 LASSERT(dentry->d_inode != NULL);
95 if (!S_ISDIR(dentry->d_inode->i_mode))
98 sbi = ll_i2sbi(dentry->d_inode);
101 CERROR("suid directory found, but no "
102 "vfsmount available.\n");
106 if (atomic_read(&sbi->ll_gns_enabled) == 0)
109 spin_lock(&sbi->ll_gns_lock);
112 * another thead is in progress or just finished mounting the
113 * dentry. Handling that.
115 if (sbi->ll_gns_state != LL_GNS_IDLE) {
117 * another thread is trying to mount GNS dentry. We'd like to
120 spin_unlock(&sbi->ll_gns_lock);
124 * check if dentry is mount point already, if so, do not restart
127 if (d_mountpoint(dentry))
130 spin_lock(&sbi->ll_gns_lock);
131 if (sbi->ll_gns_pending_dentry &&
132 is_subdir(sbi->ll_gns_pending_dentry, dentry)) {
133 spin_unlock(&sbi->ll_gns_lock);
136 spin_unlock(&sbi->ll_gns_lock);
139 * waiting for GNS complete and check dentry again, it may be
142 wait_for_completion(&sbi->ll_gns_mount_finished);
143 if (d_mountpoint(dentry))
147 * check for he case when there are few waiters and all they are
148 * awakened, but only one will find GNS state LL_GNS_IDLE, and
149 * the rest will face with LL_GNS_MOUNTING. --umka
151 spin_lock(&sbi->ll_gns_lock);
152 if (sbi->ll_gns_state != LL_GNS_IDLE) {
153 spin_unlock(&sbi->ll_gns_lock);
156 spin_unlock(&sbi->ll_gns_lock);
158 LASSERT(sbi->ll_gns_state == LL_GNS_IDLE);
159 CDEBUG(D_INODE, "mounting dentry %p\n", dentry);
161 /* mounting started */
162 sbi->ll_gns_state = LL_GNS_MOUNTING;
163 sbi->ll_gns_pending_dentry = dentry;
164 spin_unlock(&sbi->ll_gns_lock);
166 /* we need to build an absolute pathname to pass to mount */
167 pathpage = (char *)__get_free_page(GFP_KERNEL);
169 GOTO(cleanup, rc = -ENOMEM);
172 /* getting @dentry path stored in @pathpage. */
173 path = d_path(dentry, mnt, pathpage, PAGE_SIZE);
175 CERROR("can't build mount object path, err %d\n",
177 GOTO(cleanup, rc = PTR_ERR(path));
180 /* synchronizing with possible /proc/fs/...write */
181 down(&sbi->ll_gns_sem);
184 * mount object name is taken from sbi, where it is set in mount time or
185 * via /proc/fs... tunable. It may be ".mntinfo" or so.
189 * recursive lookup with trying to mount SUID bit marked directories on
190 * the way is not possible here, as lookup_one_len() does not pass @nd
191 * to ->lookup() and this is checked in ll_lookup_it().
193 dchild = ll_lookup_one_len(sbi->ll_gns_oname, dentry,
194 strlen(sbi->ll_gns_oname));
195 up(&sbi->ll_gns_sem);
199 if (IS_ERR(dchild)) {
200 rc = PTR_ERR(dchild);
201 CERROR("can't find mount object %*s/%*s err = %d.\n",
202 (int)dentry->d_name.len, dentry->d_name.name,
203 strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
208 /* mount object is not found */
209 if (!dchild->d_inode)
210 GOTO(cleanup, rc = -ENOENT);
212 /* check if found child is regular file */
213 if (!S_ISREG(dchild->d_inode->i_mode))
214 GOTO(cleanup, rc = -EBADF);
218 /* ok, mount object if found, opening it. */
219 mntinfo_fd = dentry_open(dchild, mnt, 0);
220 if (IS_ERR(mntinfo_fd)) {
221 CERROR("can't open mount object %*s/%*s err = %d.\n",
222 (int)dentry->d_name.len, dentry->d_name.name,
223 strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
224 (int)PTR_ERR(mntinfo_fd));
226 GOTO(cleanup, rc = PTR_ERR(mntinfo_fd));
230 if (mntinfo_fd->f_dentry->d_inode->i_size > PAGE_SIZE - 1) {
231 CERROR("mount object %*s/%*s is too big (%Ld)\n",
232 (int)dentry->d_name.len, dentry->d_name.name,
233 strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
234 mntinfo_fd->f_dentry->d_inode->i_size);
235 GOTO(cleanup, rc = -EFBIG);
238 datapage = (char *)__get_free_page(GFP_KERNEL);
240 GOTO(cleanup, rc = -ENOMEM);
244 /* read data from mount object. */
245 rc = kernel_read(mntinfo_fd, 0, datapage, PAGE_SIZE - 1);
247 CERROR("can't read mount object %*s/%*s data, err %d\n",
248 (int)dentry->d_name.len, dentry->d_name.name,
249 strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
254 /* no data in mount object? */
256 CERROR("mount object %*s/%*s is empty?\n",
257 (int)dentry->d_name.len, dentry->d_name.name,
258 strlen(sbi->ll_gns_oname), sbi->ll_gns_oname);
267 /* synchronizing with possible /proc/fs/...write */
268 down(&sbi->ll_gns_sem);
271 * upcall is initialized in mount time or via /proc/fs/... tuneable and
272 * may be /usr/lib/lustre/gns-upcall.sh
274 argv[0] = sbi->ll_gns_upcall;
279 up(&sbi->ll_gns_sem);
281 /* do not wait for helper complete here. */
282 rc = call_usermodehelper(argv[0], argv, NULL, 1);
284 CWARN("failed to call GNS upcall %s, err = %d, "
285 "checking for mount anyway\n", sbi->ll_gns_upcall, rc);
289 * waiting for dentry become mount point GNS_WAIT_ATTEMPTS times by 1
292 rc = ll_gns_wait_for_mount(dentry, 1, GNS_WAIT_ATTEMPTS);
293 LASSERT(sbi->ll_gns_state == LL_GNS_FINISHED);
295 /* checking for mount point anyway to not loss mounts */
296 if (d_mountpoint(dentry)) {
297 struct dentry *rdentry;
298 struct vfsmount *rmnt;
301 rdentry = dget(dentry);
303 if (follow_down(&rmnt, &rdentry)) {
305 * registering new mount in GNS mounts list and thus
306 * make it accessible from GNS control thread.
308 spin_lock(&dcache_lock);
309 LASSERT(list_empty(&rmnt->mnt_lustre_list));
310 list_add_tail(&rmnt->mnt_lustre_list,
312 spin_unlock(&dcache_lock);
313 rmnt->mnt_last_used = jiffies;
323 CERROR("usermode upcall %s failed to mount %s, err %d\n",
324 sbi->ll_gns_upcall, path, rc);
329 switch (cleanup_phase) {
331 free_page((unsigned long)datapage);
333 if (mntinfo_fd != NULL)
339 free_page((unsigned long)pathpage);
341 spin_lock(&sbi->ll_gns_lock);
342 sbi->ll_gns_state = LL_GNS_IDLE;
343 sbi->ll_gns_pending_dentry = NULL;
344 spin_unlock(&sbi->ll_gns_lock);
346 /* waking up all waiters after GNS state is LL_GNS_IDLE */
347 complete_all(&sbi->ll_gns_mount_finished);
348 init_completion(&sbi->ll_gns_mount_finished);
353 /* tries to umount passed @mnt. */
354 int ll_gns_umount_object(struct vfsmount *mnt)
359 CDEBUG(D_INODE, "unmounting mnt %p\n", mnt);
360 rc = do_umount(mnt, 0);
362 CDEBUG(D_INODE, "can't umount 0x%p, err = %d\n",
369 int ll_gns_check_mounts(struct ll_sb_info *sbi, int flags)
371 struct list_head check_list = LIST_HEAD_INIT(check_list);
372 struct vfsmount *mnt;
376 spin_lock(&dcache_lock);
377 list_splice_init(&sbi->ll_mnt_list, &check_list);
380 * walk the list in reverse order, and put them on the front of the sbi
381 * list each iteration; this avoids list-ordering problems if we race
382 * with another gns-mounting thread.
384 while (!list_empty(&check_list)) {
385 mnt = list_entry(check_list.prev,
391 list_del_init(&mnt->mnt_lustre_list);
393 list_add(&mnt->mnt_lustre_list,
396 /* check for timeout if needed */
397 pass = jiffies - mnt->mnt_last_used;
399 if (flags == LL_GNS_CHECK &&
400 pass < sbi->ll_gns_timeout * HZ)
405 spin_unlock(&dcache_lock);
408 ll_gns_umount_object(mnt);
411 spin_lock(&dcache_lock);
413 spin_unlock(&dcache_lock);
418 * GNS timer callback function. It restarts gns timer and wakes up GNS control
419 * thread to process mounts list.
421 void ll_gns_timer_callback(unsigned long data)
423 struct ll_sb_info *sbi = (void *)data;
426 spin_lock(&gns_lock);
427 if (list_empty(&sbi->ll_gns_sbi_head))
428 list_add(&sbi->ll_gns_sbi_head, &gns_sbi_list);
429 spin_unlock(&gns_lock);
431 wake_up(&gns_thread.t_ctl_waitq);
432 mod_timer(&sbi->ll_gns_timer,
433 jiffies + sbi->ll_gns_tick * HZ);
436 /* this function checks if something new happened to exist in gns list. */
437 static int inline ll_gns_check_event(void)
441 spin_lock(&gns_lock);
442 rc = !list_empty(&gns_sbi_list);
443 spin_unlock(&gns_lock);
448 /* should we stop GNS control thread? */
449 static int inline ll_gns_check_stop(void)
452 return (gns_thread.t_flags & SVC_STOPPING) ? 1 : 0;
455 /* GNS control thread function. */
456 static int ll_gns_thread(void *arg)
458 struct ll_gns_ctl *ctl = arg;
463 char name[sizeof(current->comm)];
464 snprintf(name, sizeof(name) - 1, "ll_gns");
465 kportal_daemonize(name);
468 SIGNAL_MASK_LOCK(current, flags);
469 sigfillset(¤t->blocked);
471 SIGNAL_MASK_UNLOCK(current, flags);
474 * letting starting function know, that we are ready and control may be
477 gns_thread.t_flags = SVC_RUNNING;
478 complete(&ctl->gc_starting);
480 while (!ll_gns_check_stop()) {
481 struct l_wait_info lwi = { 0 };
483 l_wait_event(gns_thread.t_ctl_waitq,
484 (ll_gns_check_event() ||
485 ll_gns_check_stop()), &lwi);
487 spin_lock(&gns_lock);
488 while (!list_empty(&gns_sbi_list)) {
489 struct ll_sb_info *sbi;
491 sbi = list_entry(gns_sbi_list.prev,
495 list_del_init(&sbi->ll_gns_sbi_head);
496 spin_unlock(&gns_lock);
497 ll_gns_check_mounts(sbi, LL_GNS_CHECK);
498 spin_lock(&gns_lock);
500 spin_unlock(&gns_lock);
504 gns_thread.t_flags = SVC_STOPPED;
506 /* this is SMP-safe way to finish thread. */
507 complete_and_exit(&ctl->gc_finishing, 0);
510 void ll_gns_add_timer(struct ll_sb_info *sbi)
512 mod_timer(&sbi->ll_gns_timer,
513 jiffies + sbi->ll_gns_tick * HZ);
516 void ll_gns_del_timer(struct ll_sb_info *sbi)
518 del_timer(&sbi->ll_gns_timer);
522 * starts GNS control thread and waits for a signal it is up and work may be
525 int ll_gns_start_thread(void)
530 LASSERT(gns_thread.t_flags == 0);
531 init_completion(&gns_ctl.gc_starting);
532 init_completion(&gns_ctl.gc_finishing);
533 init_waitqueue_head(&gns_thread.t_ctl_waitq);
535 rc = kernel_thread(ll_gns_thread, &gns_ctl,
536 (CLONE_VM | CLONE_FILES));
538 CERROR("cannot start GNS control thread, "
542 wait_for_completion(&gns_ctl.gc_starting);
543 LASSERT(gns_thread.t_flags == SVC_RUNNING);
547 /* stops GNS control thread and waits its actual stop. */
548 void ll_gns_stop_thread(void)
551 gns_thread.t_flags = SVC_STOPPING;
552 wake_up(&gns_thread.t_ctl_waitq);
553 wait_for_completion(&gns_ctl.gc_finishing);
554 LASSERT(gns_thread.t_flags == SVC_STOPPED);
555 gns_thread.t_flags = 0;