1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
5 * Lustre Metadata Server (MDS) filesystem interface code
7 * Copyright (C) 2002, 2003 Cluster File Systems, Inc.
8 * Author: Andreas Dilger <adilger@clusterfs.com>
10 * This file is part of Lustre, http://www.lustre.org.
12 * Lustre is free software; you can redistribute it and/or
13 * modify it under the terms of version 2 of the GNU General Public
14 * License as published by the Free Software Foundation.
16 * Lustre is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with Lustre; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 # define EXPORT_SYMTAB
29 #define DEBUG_SUBSYSTEM S_MDS
31 #include <linux/module.h>
32 #include <linux/kmod.h>
33 #include <linux/version.h>
34 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
35 #include <linux/mount.h>
37 #include <linux/lustre_mds.h>
38 #include <linux/obd_class.h>
39 #include <linux/obd_support.h>
40 #include <linux/lustre_lib.h>
41 #include <linux/lustre_fsfilt.h>
42 #include <portals/list.h>
44 #include "mds_internal.h"
46 /* This limit is arbitrary, but for now we fit it in 1 page (32k clients) */
47 #define MDS_MAX_CLIENTS (PAGE_SIZE * 8)
48 #define MDS_MAX_CLIENT_WORDS (MDS_MAX_CLIENTS / sizeof(unsigned long))
50 #define LAST_RCVD "last_rcvd"
51 #define LOV_OBJID "lov_objid"
53 /* Add client data to the MDS. We use a bitmap to locate a free space
54 * in the last_rcvd file if cl_off is -1 (i.e. a new client).
55 * Otherwise, we have just read the data from the last_rcvd file and
58 int mds_client_add(struct obd_device *obd, struct mds_obd *mds,
59 struct mds_export_data *med, int cl_idx)
61 unsigned long *bitmap = mds->mds_client_bitmap;
62 int new_client = (cl_idx == -1);
65 LASSERT(bitmap != NULL);
67 /* XXX if mcd_uuid were a real obd_uuid, I could use obd_uuid_equals */
68 if (!strcmp(med->med_mcd->mcd_uuid, obd->obd_uuid.uuid))
71 /* the bitmap operations can handle cl_idx > sizeof(long) * 8, so
72 * there's no need for extra complication here
75 cl_idx = find_first_zero_bit(bitmap, MDS_MAX_CLIENTS);
77 if (cl_idx >= MDS_MAX_CLIENTS) {
78 CERROR("no room for clients - fix MDS_MAX_CLIENTS\n");
81 if (test_and_set_bit(cl_idx, bitmap)) {
82 cl_idx = find_next_zero_bit(bitmap, MDS_MAX_CLIENTS,
87 if (test_and_set_bit(cl_idx, bitmap)) {
88 CERROR("MDS client %d: bit already set in bitmap!!\n",
94 CDEBUG(D_INFO, "client at idx %d with UUID '%s' added\n",
95 cl_idx, med->med_mcd->mcd_uuid);
97 med->med_idx = cl_idx;
98 med->med_off = MDS_LR_CLIENT_START + (cl_idx * MDS_LR_CLIENT_SIZE);
101 struct obd_run_ctxt saved;
102 loff_t off = med->med_off;
103 struct file *file = mds->mds_rcvd_filp;
106 push_ctxt(&saved, &obd->obd_ctxt, NULL);
107 rc = fsfilt_write_record(obd, file, med->med_mcd,
108 sizeof(*med->med_mcd), &off, 1);
109 pop_ctxt(&saved, &obd->obd_ctxt, NULL);
113 CDEBUG(D_INFO, "wrote client mcd at idx %u off %llu (len %u)\n",
114 med->med_idx, med->med_off,
115 (unsigned int)sizeof(*med->med_mcd));
120 int mds_client_free(struct obd_export *exp, int clear_client)
122 struct mds_export_data *med = &exp->exp_mds_data;
123 struct mds_obd *mds = &exp->exp_obd->u.mds;
124 struct obd_device *obd = exp->exp_obd;
125 struct mds_client_data zero_mcd;
126 struct obd_run_ctxt saved;
128 unsigned long *bitmap = mds->mds_client_bitmap;
134 /* XXX if mcd_uuid were a real obd_uuid, I could use obd_uuid_equals */
135 if (!strcmp(med->med_mcd->mcd_uuid, obd->obd_uuid.uuid))
136 GOTO(free_and_out, 0);
138 CDEBUG(D_INFO, "freeing client at idx %u (%lld)with UUID '%s'\n",
139 med->med_idx, med->med_off, med->med_mcd->mcd_uuid);
141 /* Clear the bit _after_ zeroing out the client so we don't
142 race with mds_client_add and zero out new clients.*/
143 if (!test_bit(med->med_idx, bitmap)) {
144 CERROR("MDS client %u: bit already clear in bitmap!!\n",
150 memset(&zero_mcd, 0, sizeof zero_mcd);
151 push_ctxt(&saved, &obd->obd_ctxt, NULL);
152 rc = fsfilt_write_record(obd, mds->mds_rcvd_filp, &zero_mcd,
153 sizeof(zero_mcd), &med->med_off, 1);
154 pop_ctxt(&saved, &obd->obd_ctxt, NULL);
156 CDEBUG(rc == 0 ? D_INFO : D_ERROR,
157 "zeroing out client %s idx %u in %s rc %d\n",
158 med->med_mcd->mcd_uuid, med->med_idx, LAST_RCVD, rc);
161 if (!test_and_clear_bit(med->med_idx, bitmap)) {
162 CERROR("MDS client %u: bit already clear in bitmap!!\n",
168 OBD_FREE(med->med_mcd, sizeof(*med->med_mcd));
173 static int mds_server_free_data(struct mds_obd *mds)
175 OBD_FREE(mds->mds_client_bitmap,
176 MDS_MAX_CLIENT_WORDS * sizeof(unsigned long));
177 OBD_FREE(mds->mds_server_data, sizeof(*mds->mds_server_data));
178 mds->mds_server_data = NULL;
183 static int mds_read_last_rcvd(struct obd_device *obd, struct file *file)
185 struct mds_obd *mds = &obd->u.mds;
186 struct mds_server_data *msd;
187 struct mds_client_data *mcd = NULL;
189 unsigned long last_rcvd_size = file->f_dentry->d_inode->i_size;
194 /* ensure padding in the struct is the correct size */
195 LASSERT (offsetof(struct mds_server_data, msd_padding) +
196 sizeof(msd->msd_padding) == MDS_LR_SERVER_SIZE);
197 LASSERT (offsetof(struct mds_client_data, mcd_padding) +
198 sizeof(mcd->mcd_padding) == MDS_LR_CLIENT_SIZE);
200 OBD_ALLOC_WAIT(msd, sizeof(*msd));
204 OBD_ALLOC_WAIT(mds->mds_client_bitmap,
205 MDS_MAX_CLIENT_WORDS * sizeof(unsigned long));
206 if (!mds->mds_client_bitmap) {
207 OBD_FREE(msd, sizeof(*msd));
211 mds->mds_server_data = msd;
213 if (last_rcvd_size == 0) {
214 CWARN("%s: initializing new %s\n", obd->obd_name, LAST_RCVD);
216 memcpy(msd->msd_uuid, obd->obd_uuid.uuid,sizeof(msd->msd_uuid));
217 msd->msd_last_transno = 0;
218 mount_count = msd->msd_mount_count = 0;
219 msd->msd_server_size = cpu_to_le32(MDS_LR_SERVER_SIZE);
220 msd->msd_client_start = cpu_to_le32(MDS_LR_CLIENT_START);
221 msd->msd_client_size = cpu_to_le16(MDS_LR_CLIENT_SIZE);
222 msd->msd_feature_rocompat = cpu_to_le32(MDS_ROCOMPAT_LOVOBJID);
224 rc = fsfilt_read_record(obd, file, msd, sizeof(*msd), &off);
226 CERROR("error reading MDS %s: rc = %d\n", LAST_RCVD, rc);
229 if (strcmp(msd->msd_uuid, obd->obd_uuid.uuid) != 0) {
230 CERROR("OBD UUID %s does not match last_rcvd UUID %s\n",
231 obd->obd_uuid.uuid, msd->msd_uuid);
232 GOTO(err_msd, rc = -EINVAL);
234 mount_count = le64_to_cpu(msd->msd_mount_count);
236 if (msd->msd_feature_incompat & ~cpu_to_le32(MDS_INCOMPAT_SUPP)) {
237 CERROR("unsupported incompat feature %x\n",
238 le32_to_cpu(msd->msd_feature_incompat) &
240 GOTO(err_msd, rc = -EINVAL);
242 /* XXX updating existing b_devel fs only, can be removed in future */
243 msd->msd_feature_rocompat = cpu_to_le32(MDS_ROCOMPAT_LOVOBJID);
244 if (msd->msd_feature_rocompat & ~cpu_to_le32(MDS_ROCOMPAT_SUPP)) {
245 CERROR("unsupported read-only feature %x\n",
246 le32_to_cpu(msd->msd_feature_rocompat) &
248 /* Do something like remount filesystem read-only */
249 GOTO(err_msd, rc = -EINVAL);
252 mds->mds_last_transno = le64_to_cpu(msd->msd_last_transno);
254 CDEBUG(D_INODE, "%s: server last_transno: "LPU64"\n",
255 obd->obd_name, mds->mds_last_transno);
256 CDEBUG(D_INODE, "%s: server mount_count: "LPU64"\n",
257 obd->obd_name, mount_count + 1);
258 CDEBUG(D_INODE, "%s: server data size: %u\n",
259 obd->obd_name, le32_to_cpu(msd->msd_server_size));
260 CDEBUG(D_INODE, "%s: per-client data start: %u\n",
261 obd->obd_name, le32_to_cpu(msd->msd_client_start));
262 CDEBUG(D_INODE, "%s: per-client data size: %u\n",
263 obd->obd_name, le32_to_cpu(msd->msd_client_size));
264 CDEBUG(D_INODE, "%s: last_rcvd size: %lu\n",
265 obd->obd_name, last_rcvd_size);
266 CDEBUG(D_INODE, "%s: last_rcvd clients: %lu\n", obd->obd_name,
267 last_rcvd_size <= MDS_LR_CLIENT_START ? 0 :
268 (last_rcvd_size - MDS_LR_CLIENT_START) / MDS_LR_CLIENT_SIZE);
270 /* When we do a clean MDS shutdown, we save the last_transno into
271 * the header. If we find clients with higher last_transno values
272 * then those clients may need recovery done. */
273 for (cl_idx = 0, off = le32_to_cpu(msd->msd_client_start);
274 off < last_rcvd_size; cl_idx++) {
276 struct obd_export *exp;
277 struct mds_export_data *med;
280 OBD_ALLOC_WAIT(mcd, sizeof(*mcd));
282 GOTO(err_client, rc = -ENOMEM);
285 /* Don't assume off is incremented properly by
286 * fsfilt_read_record(), in case sizeof(*mcd)
287 * isn't the same as msd->msd_client_size. */
288 off = le32_to_cpu(msd->msd_client_start) +
289 cl_idx * le16_to_cpu(msd->msd_client_size);
290 rc = fsfilt_read_record(obd, file, mcd, sizeof(*mcd), &off);
292 CERROR("error reading MDS %s idx %d, off %llu: rc %d\n",
293 LAST_RCVD, cl_idx, off, rc);
294 break; /* read error shouldn't cause startup to fail */
297 if (mcd->mcd_uuid[0] == '\0') {
298 CDEBUG(D_INFO, "skipping zeroed client at offset %d\n",
303 last_transno = le64_to_cpu(mcd->mcd_last_transno);
305 /* These exports are cleaned up by mds_disconnect(), so they
306 * need to be set up like real exports as mds_connect() does.
308 CDEBUG(D_HA, "RCVRNG CLIENT uuid: %s idx: %d lr: "LPU64
309 " srv lr: "LPU64"\n", mcd->mcd_uuid, cl_idx,
310 last_transno, le64_to_cpu(msd->msd_last_transno));
312 exp = class_new_export(obd);
314 GOTO(err_client, rc = -ENOMEM);
316 memcpy(&exp->exp_client_uuid.uuid, mcd->mcd_uuid,
317 sizeof exp->exp_client_uuid.uuid);
318 med = &exp->exp_mds_data;
320 mds_client_add(obd, mds, med, cl_idx);
321 /* create helper if export init gets more complex */
322 INIT_LIST_HEAD(&med->med_open_head);
323 spin_lock_init(&med->med_open_lock);
326 obd->obd_recoverable_clients++;
327 obd->obd_max_recoverable_clients++;
328 class_export_put(exp);
330 CDEBUG(D_OTHER, "client at idx %d has last_transno = "LPU64"\n",
331 cl_idx, last_transno);
333 if (last_transno > mds->mds_last_transno)
334 mds->mds_last_transno = last_transno;
337 obd->obd_last_committed = mds->mds_last_transno;
338 if (obd->obd_recoverable_clients) {
339 CWARN("RECOVERY: service %s, %d recoverable clients, "
340 "last_transno "LPU64"\n", obd->obd_name,
341 obd->obd_recoverable_clients, mds->mds_last_transno);
342 obd->obd_next_recovery_transno = obd->obd_last_committed + 1;
343 obd->obd_recovering = 1;
347 OBD_FREE(mcd, sizeof(*mcd));
349 mds->mds_mount_count = mount_count + 1;
350 msd->msd_mount_count = cpu_to_le64(mds->mds_mount_count);
352 /* save it, so mount count and last_transno is current */
353 rc = mds_update_server_data(obd, 1);
358 class_disconnect_exports(obd, 0);
360 mds_server_free_data(mds);
364 int mds_fs_setup(struct obd_device *obd, struct vfsmount *mnt)
366 struct mds_obd *mds = &obd->u.mds;
367 struct obd_run_ctxt saved;
368 struct dentry *dentry;
374 /* Get rid of unneeded supplementary groups */
375 current->ngroups = 0;
376 memset(current->groups, 0, sizeof(current->groups));
378 mds->mds_vfsmnt = mnt;
379 mds->mds_sb = mnt->mnt_root->d_inode->i_sb;
381 fsfilt_setup(obd, mds->mds_sb);
383 OBD_SET_CTXT_MAGIC(&obd->obd_ctxt);
384 obd->obd_ctxt.pwdmnt = mnt;
385 obd->obd_ctxt.pwd = mnt->mnt_root;
386 obd->obd_ctxt.fs = get_ds();
387 obd->obd_ctxt.cb_ops = mds_lvfs_ops;
389 /* setup the directory tree */
390 push_ctxt(&saved, &obd->obd_ctxt, NULL);
391 dentry = simple_mkdir(current->fs->pwd, "ROOT", 0755);
392 if (IS_ERR(dentry)) {
393 rc = PTR_ERR(dentry);
394 CERROR("cannot create ROOT directory: rc = %d\n", rc);
398 mds->mds_rootfid.id = dentry->d_inode->i_ino;
399 mds->mds_rootfid.generation = dentry->d_inode->i_generation;
400 mds->mds_rootfid.f_type = S_IFDIR;
404 dentry = lookup_one_len("__iopen__", current->fs->pwd,
405 strlen("__iopen__"));
406 if (IS_ERR(dentry) || !dentry->d_inode) {
407 rc = (IS_ERR(dentry)) ? PTR_ERR(dentry): -ENOENT;
408 CERROR("cannot open iopen FH directory: rc = %d\n", rc);
411 mds->mds_fid_de = dentry;
413 dentry = simple_mkdir(current->fs->pwd, "PENDING", 0777);
414 if (IS_ERR(dentry)) {
415 rc = PTR_ERR(dentry);
416 CERROR("cannot create PENDING directory: rc = %d\n", rc);
419 mds->mds_pending_dir = dentry;
421 dentry = simple_mkdir(current->fs->pwd, "LOGS", 0777);
422 if (IS_ERR(dentry)) {
423 rc = PTR_ERR(dentry);
424 CERROR("cannot create LOGS directory: rc = %d\n", rc);
425 GOTO(err_pending, rc);
427 mds->mds_logs_dir = dentry;
429 dentry = simple_mkdir(current->fs->pwd, "OBJECTS", 0777);
430 if (IS_ERR(dentry)) {
431 rc = PTR_ERR(dentry);
432 CERROR("cannot create OBJECTS directory: rc = %d\n", rc);
435 mds->mds_objects_dir = dentry;
437 /* open and test the last rcvd file */
438 file = filp_open(LAST_RCVD, O_RDWR | O_CREAT, 0644);
441 CERROR("cannot open/create %s file: rc = %d\n", LAST_RCVD, rc);
442 GOTO(err_objects, rc = PTR_ERR(file));
444 mds->mds_rcvd_filp = file;
445 if (!S_ISREG(file->f_dentry->d_inode->i_mode)) {
446 CERROR("%s is not a regular file!: mode = %o\n", LAST_RCVD,
447 file->f_dentry->d_inode->i_mode);
448 GOTO(err_last_rcvd, rc = -ENOENT);
451 rc = mds_read_last_rcvd(obd, file);
453 CERROR("cannot read %s: rc = %d\n", LAST_RCVD, rc);
454 GOTO(err_last_rcvd, rc);
457 /* open and test the lov objd file */
458 file = filp_open(LOV_OBJID, O_RDWR | O_CREAT, 0644);
461 CERROR("cannot open/create %s file: rc = %d\n", LOV_OBJID, rc);
462 GOTO(err_client, rc = PTR_ERR(file));
464 mds->mds_lov_objid_filp = file;
465 if (!S_ISREG(file->f_dentry->d_inode->i_mode)) {
466 CERROR("%s is not a regular file!: mode = %o\n", LOV_OBJID,
467 file->f_dentry->d_inode->i_mode);
468 GOTO(err_lov_objid, rc = -ENOENT);
471 pop_ctxt(&saved, &obd->obd_ctxt, NULL);
476 if (mds->mds_lov_objid_filp && filp_close(mds->mds_lov_objid_filp, 0))
477 CERROR("can't close %s after error\n", LOV_OBJID);
479 class_disconnect_exports(obd, 0);
481 if (mds->mds_rcvd_filp && filp_close(mds->mds_rcvd_filp, 0))
482 CERROR("can't close %s after error\n", LAST_RCVD);
484 dput(mds->mds_objects_dir);
486 dput(mds->mds_logs_dir);
488 dput(mds->mds_pending_dir);
490 dput(mds->mds_fid_de);
495 int mds_fs_cleanup(struct obd_device *obd, int flags)
497 struct mds_obd *mds = &obd->u.mds;
498 struct obd_run_ctxt saved;
501 if (flags & OBD_OPT_FAILOVER)
502 CERROR("%s: shutting down for failover; client state will"
503 " be preserved.\n", obd->obd_name);
505 class_disconnect_exports(obd, flags); /* cleans up client info too */
506 mds_server_free_data(mds);
508 push_ctxt(&saved, &obd->obd_ctxt, NULL);
509 if (mds->mds_rcvd_filp) {
510 rc = filp_close(mds->mds_rcvd_filp, 0);
511 mds->mds_rcvd_filp = NULL;
513 CERROR("%s file won't close, rc=%d\n", LAST_RCVD, rc);
515 if (mds->mds_lov_objid_filp) {
516 rc = filp_close(mds->mds_lov_objid_filp, 0);
517 mds->mds_lov_objid_filp = NULL;
519 CERROR("%s file won't close, rc=%d\n", LOV_OBJID, rc);
521 if (mds->mds_objects_dir != NULL) {
522 l_dput(mds->mds_objects_dir);
523 mds->mds_objects_dir = NULL;
525 if (mds->mds_logs_dir) {
526 l_dput(mds->mds_logs_dir);
527 mds->mds_logs_dir = NULL;
529 if (mds->mds_pending_dir) {
530 l_dput(mds->mds_pending_dir);
531 mds->mds_pending_dir = NULL;
533 pop_ctxt(&saved, &obd->obd_ctxt, NULL);
534 shrink_dcache_parent(mds->mds_fid_de);
535 dput(mds->mds_fid_de);
540 /* Creates an object with the same name as its fid. Because this is not at all
541 * performance sensitive, it is accomplished by creating a file, checking the
542 * fid, and renaming it. */
543 int mds_obd_create(struct obd_export *exp, struct obdo *oa,
544 struct lov_stripe_md **ea, struct obd_trans_info *oti)
546 struct mds_obd *mds = &exp->exp_obd->u.mds;
547 struct inode *parent_inode = mds->mds_objects_dir->d_inode;
548 unsigned int tmpname = ll_insecure_random_int();
550 struct dentry *new_child;
551 struct obd_run_ctxt saved;
552 char fidname[LL_FID_NAMELEN];
554 int rc = 0, err, namelen;
557 push_ctxt(&saved, &exp->exp_obd->obd_ctxt, NULL);
559 sprintf(fidname, "OBJECTS/%u", tmpname);
560 filp = filp_open(fidname, O_CREAT | O_EXCL, 0644);
564 CERROR("impossible object name collision %u\n",
568 CERROR("error creating tmp object %u: rc %d\n", tmpname, rc);
572 LASSERT(mds->mds_objects_dir == filp->f_dentry->d_parent);
574 oa->o_id = filp->f_dentry->d_inode->i_ino;
575 oa->o_generation = filp->f_dentry->d_inode->i_generation;
576 namelen = ll_fid2str(fidname, oa->o_id, oa->o_generation);
578 down(&parent_inode->i_sem);
579 new_child = lookup_one_len(fidname, mds->mds_objects_dir, namelen);
581 if (IS_ERR(new_child)) {
582 CERROR("getting neg dentry for obj rename: %d\n", rc);
583 GOTO(out_close, rc = PTR_ERR(new_child));
585 if (new_child->d_inode != NULL) {
586 CERROR("impossible non-negative obj dentry " LPU64":%u!\n",
587 oa->o_id, oa->o_generation);
591 handle = fsfilt_start(exp->exp_obd, mds->mds_objects_dir->d_inode,
592 FSFILT_OP_RENAME, NULL);
594 GOTO(out_dput, rc = PTR_ERR(handle));
597 rc = vfs_rename(mds->mds_objects_dir->d_inode, filp->f_dentry,
598 mds->mds_objects_dir->d_inode, new_child);
601 CERROR("error renaming new object "LPU64":%u: rc %d\n",
602 oa->o_id, oa->o_generation, rc);
604 err = fsfilt_commit(exp->exp_obd, mds->mds_objects_dir->d_inode,
607 oa->o_valid |= OBD_MD_FLID | OBD_MD_FLGENER;
613 up(&parent_inode->i_sem);
614 err = filp_close(filp, 0);
616 CERROR("closing tmpfile %u: rc %d\n", tmpname, rc);
621 pop_ctxt(&saved, &exp->exp_obd->obd_ctxt, NULL);
625 int mds_obd_destroy(struct obd_export *exp, struct obdo *oa,
626 struct lov_stripe_md *ea, struct obd_trans_info *oti)
628 struct mds_obd *mds = &exp->exp_obd->u.mds;
629 struct inode *parent_inode = mds->mds_objects_dir->d_inode;
630 struct obd_device *obd = exp->exp_obd;
631 struct obd_run_ctxt saved;
632 char fidname[LL_FID_NAMELEN];
635 int err, namelen, rc = 0;
638 push_ctxt(&saved, &obd->obd_ctxt, NULL);
640 namelen = ll_fid2str(fidname, oa->o_id, oa->o_generation);
642 down(&parent_inode->i_sem);
643 de = lookup_one_len(fidname, mds->mds_objects_dir, namelen);
644 if (de == NULL || de->d_inode == NULL) {
645 CERROR("destroying non-existent object "LPU64"\n", oa->o_id);
646 GOTO(out, rc = IS_ERR(de) ? PTR_ERR(de) : -ENOENT);
649 handle = fsfilt_start(obd, mds->mds_objects_dir->d_inode,
650 FSFILT_OP_UNLINK_LOG, oti);
651 if (IS_ERR(handle)) {
652 GOTO(out_dput, rc = PTR_ERR(handle));
655 rc = vfs_unlink(mds->mds_objects_dir->d_inode, de);
657 CERROR("error destroying object "LPU64":%u: rc %d\n",
658 oa->o_id, oa->o_generation, rc);
660 err = fsfilt_commit(obd, mds->mds_objects_dir->d_inode, handle, 0);
666 up(&parent_inode->i_sem);
667 pop_ctxt(&saved, &obd->obd_ctxt, NULL);