xref: /openbmc/linux/fs/gfs2/inode.c (revision c2668711)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/posix_acl.h>
16 #include <linux/sort.h>
17 #include <linux/gfs2_ondisk.h>
18 #include <linux/crc32.h>
19 
20 #include "gfs2.h"
21 #include "lm_interface.h"
22 #include "incore.h"
23 #include "acl.h"
24 #include "bmap.h"
25 #include "dir.h"
26 #include "eattr.h"
27 #include "glock.h"
28 #include "glops.h"
29 #include "inode.h"
30 #include "log.h"
31 #include "meta_io.h"
32 #include "ops_address.h"
33 #include "ops_file.h"
34 #include "ops_inode.h"
35 #include "quota.h"
36 #include "rgrp.h"
37 #include "trans.h"
38 #include "util.h"
39 
40 /**
41  * gfs2_inode_attr_in - Copy attributes from the dinode into the VFS inode
42  * @ip: The GFS2 inode (with embedded disk inode data)
43  * @inode:  The Linux VFS inode
44  *
45  */
46 
47 void gfs2_inode_attr_in(struct gfs2_inode *ip)
48 {
49 	struct inode *inode = &ip->i_inode;
50 	struct gfs2_dinode *di = &ip->i_di;
51 
52 	inode->i_ino = ip->i_num.no_addr;
53 
54 	switch (di->di_mode & S_IFMT) {
55 	case S_IFBLK:
56 	case S_IFCHR:
57 		inode->i_rdev = MKDEV(di->di_major, di->di_minor);
58 		break;
59 	default:
60 		inode->i_rdev = 0;
61 		break;
62 	};
63 
64 	inode->i_mode = di->di_mode;
65 	inode->i_nlink = di->di_nlink;
66 	inode->i_uid = di->di_uid;
67 	inode->i_gid = di->di_gid;
68 	i_size_write(inode, di->di_size);
69 	inode->i_atime.tv_sec = di->di_atime;
70 	inode->i_mtime.tv_sec = di->di_mtime;
71 	inode->i_ctime.tv_sec = di->di_ctime;
72 	inode->i_atime.tv_nsec = 0;
73 	inode->i_mtime.tv_nsec = 0;
74 	inode->i_ctime.tv_nsec = 0;
75 	inode->i_blksize = PAGE_SIZE;
76 	inode->i_blocks = di->di_blocks <<
77 		(GFS2_SB(inode)->sd_sb.sb_bsize_shift - GFS2_BASIC_BLOCK_SHIFT);
78 
79 	if (di->di_flags & GFS2_DIF_IMMUTABLE)
80 		inode->i_flags |= S_IMMUTABLE;
81 	else
82 		inode->i_flags &= ~S_IMMUTABLE;
83 
84 	if (di->di_flags & GFS2_DIF_APPENDONLY)
85 		inode->i_flags |= S_APPEND;
86 	else
87 		inode->i_flags &= ~S_APPEND;
88 }
89 
90 /**
91  * gfs2_inode_attr_out - Copy attributes from VFS inode into the dinode
92  * @ip: The GFS2 inode
93  *
94  * Only copy out the attributes that we want the VFS layer
95  * to be able to modify.
96  */
97 
98 void gfs2_inode_attr_out(struct gfs2_inode *ip)
99 {
100 	struct inode *inode = &ip->i_inode;
101 	struct gfs2_dinode *di = &ip->i_di;
102 	gfs2_assert_withdraw(GFS2_SB(inode),
103 		(di->di_mode & S_IFMT) == (inode->i_mode & S_IFMT));
104 	di->di_mode = inode->i_mode;
105 	di->di_uid = inode->i_uid;
106 	di->di_gid = inode->i_gid;
107 	di->di_atime = inode->i_atime.tv_sec;
108 	di->di_mtime = inode->i_mtime.tv_sec;
109 	di->di_ctime = inode->i_ctime.tv_sec;
110 }
111 
112 static int iget_test(struct inode *inode, void *opaque)
113 {
114 	struct gfs2_inode *ip = GFS2_I(inode);
115 	struct gfs2_inum *inum = opaque;
116 
117 	if (ip && ip->i_num.no_addr == inum->no_addr)
118 		return 1;
119 
120 	return 0;
121 }
122 
123 static int iget_set(struct inode *inode, void *opaque)
124 {
125 	struct gfs2_inode *ip = GFS2_I(inode);
126 	struct gfs2_inum *inum = opaque;
127 
128 	ip->i_num = *inum;
129 	return 0;
130 }
131 
132 struct inode *gfs2_ilookup(struct super_block *sb, struct gfs2_inum *inum)
133 {
134 	return ilookup5(sb, (unsigned long)inum->no_formal_ino,
135 			iget_test, inum);
136 }
137 
138 static struct inode *gfs2_iget(struct super_block *sb, struct gfs2_inum *inum)
139 {
140 	return iget5_locked(sb, (unsigned long)inum->no_formal_ino,
141 		     iget_test, iget_set, inum);
142 }
143 
144 /**
145  * gfs2_inode_lookup - Lookup an inode
146  * @sb: The super block
147  * @inum: The inode number
148  * @type: The type of the inode
149  *
150  * Returns: A VFS inode, or an error
151  */
152 
153 struct inode *gfs2_inode_lookup(struct super_block *sb, struct gfs2_inum *inum, unsigned int type)
154 {
155 	struct inode *inode = gfs2_iget(sb, inum);
156 	struct gfs2_inode *ip = GFS2_I(inode);
157 	struct gfs2_glock *io_gl;
158 	int error;
159 
160 	if (inode->i_state & I_NEW) {
161 		struct gfs2_sbd *sdp = GFS2_SB(inode);
162 		umode_t mode = DT2IF(type);
163 		inode->u.generic_ip = ip;
164 		inode->i_mode = mode;
165 
166 		if (S_ISREG(mode)) {
167 			inode->i_op = &gfs2_file_iops;
168 			inode->i_fop = &gfs2_file_fops;
169 			inode->i_mapping->a_ops = &gfs2_file_aops;
170 		} else if (S_ISDIR(mode)) {
171 			inode->i_op = &gfs2_dir_iops;
172 			inode->i_fop = &gfs2_dir_fops;
173 		} else if (S_ISLNK(mode)) {
174 			inode->i_op = &gfs2_symlink_iops;
175 		} else {
176 			inode->i_op = &gfs2_dev_iops;
177 		}
178 
179 		error = gfs2_glock_get(sdp, inum->no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
180 		if (unlikely(error))
181 			goto fail;
182 		ip->i_gl->gl_object = ip;
183 
184 		error = gfs2_glock_get(sdp, inum->no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
185 		if (unlikely(error))
186 			goto fail_put;
187 
188 		ip->i_vn = ip->i_gl->gl_vn - 1;
189 		error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
190 		if (unlikely(error))
191 			goto fail_iopen;
192 
193 		gfs2_glock_put(io_gl);
194 		unlock_new_inode(inode);
195 	}
196 
197 	return inode;
198 fail_iopen:
199 	gfs2_glock_put(io_gl);
200 fail_put:
201 	ip->i_gl->gl_object = NULL;
202 	gfs2_glock_put(ip->i_gl);
203 fail:
204 	iput(inode);
205 	return ERR_PTR(error);
206 }
207 
208 /**
209  * gfs2_inode_refresh - Refresh the incore copy of the dinode
210  * @ip: The GFS2 inode
211  *
212  * Returns: errno
213  */
214 
215 int gfs2_inode_refresh(struct gfs2_inode *ip)
216 {
217 	struct buffer_head *dibh;
218 	int error;
219 
220 	error = gfs2_meta_inode_buffer(ip, &dibh);
221 	if (error)
222 		return error;
223 
224 	if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), dibh, GFS2_METATYPE_DI)) {
225 		brelse(dibh);
226 		return -EIO;
227 	}
228 
229 	gfs2_dinode_in(&ip->i_di, dibh->b_data);
230 
231 	brelse(dibh);
232 
233 	if (ip->i_num.no_addr != ip->i_di.di_num.no_addr) {
234 		if (gfs2_consist_inode(ip))
235 			gfs2_dinode_print(&ip->i_di);
236 		return -EIO;
237 	}
238 	if (ip->i_num.no_formal_ino != ip->i_di.di_num.no_formal_ino)
239 		return -ESTALE;
240 
241 	ip->i_vn = ip->i_gl->gl_vn;
242 
243 	return 0;
244 }
245 
246 int gfs2_dinode_dealloc(struct gfs2_inode *ip)
247 {
248 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
249 	struct gfs2_alloc *al;
250 	struct gfs2_rgrpd *rgd;
251 	int error;
252 
253 	if (ip->i_di.di_blocks != 1) {
254 		if (gfs2_consist_inode(ip))
255 			gfs2_dinode_print(&ip->i_di);
256 		return -EIO;
257 	}
258 
259 	al = gfs2_alloc_get(ip);
260 
261 	error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
262 	if (error)
263 		goto out;
264 
265 	error = gfs2_rindex_hold(sdp, &al->al_ri_gh);
266 	if (error)
267 		goto out_qs;
268 
269 	rgd = gfs2_blk2rgrpd(sdp, ip->i_num.no_addr);
270 	if (!rgd) {
271 		gfs2_consist_inode(ip);
272 		error = -EIO;
273 		goto out_rindex_relse;
274 	}
275 
276 	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0,
277 				   &al->al_rgd_gh);
278 	if (error)
279 		goto out_rindex_relse;
280 
281 	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA, 1);
282 	if (error)
283 		goto out_rg_gunlock;
284 
285 	gfs2_trans_add_gl(ip->i_gl);
286 
287 	gfs2_free_di(rgd, ip);
288 
289 	gfs2_trans_end(sdp);
290 	clear_bit(GLF_STICKY, &ip->i_gl->gl_flags);
291 
292 out_rg_gunlock:
293 	gfs2_glock_dq_uninit(&al->al_rgd_gh);
294 out_rindex_relse:
295 	gfs2_glock_dq_uninit(&al->al_ri_gh);
296 out_qs:
297 	gfs2_quota_unhold(ip);
298 out:
299 	gfs2_alloc_put(ip);
300 	return error;
301 }
302 
303 /**
304  * gfs2_change_nlink - Change nlink count on inode
305  * @ip: The GFS2 inode
306  * @diff: The change in the nlink count required
307  *
308  * Returns: errno
309  */
310 
311 int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
312 {
313 	struct gfs2_sbd *sdp = ip->i_inode.i_sb->s_fs_info;
314 	struct buffer_head *dibh;
315 	u32 nlink;
316 	int error;
317 
318 	BUG_ON(ip->i_di.di_nlink != ip->i_inode.i_nlink);
319 	nlink = ip->i_di.di_nlink + diff;
320 
321 	/* If we are reducing the nlink count, but the new value ends up being
322 	   bigger than the old one, we must have underflowed. */
323 	if (diff < 0 && nlink > ip->i_di.di_nlink) {
324 		if (gfs2_consist_inode(ip))
325 			gfs2_dinode_print(&ip->i_di);
326 		return -EIO;
327 	}
328 
329 	error = gfs2_meta_inode_buffer(ip, &dibh);
330 	if (error)
331 		return error;
332 
333 	ip->i_di.di_nlink = nlink;
334 	ip->i_di.di_ctime = get_seconds();
335 	ip->i_inode.i_nlink = nlink;
336 
337 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
338 	gfs2_dinode_out(&ip->i_di, dibh->b_data);
339 	brelse(dibh);
340 	mark_inode_dirty(&ip->i_inode);
341 
342 	if (ip->i_di.di_nlink == 0) {
343 		struct gfs2_rgrpd *rgd;
344 		struct gfs2_holder ri_gh, rg_gh;
345 
346 		error = gfs2_rindex_hold(sdp, &ri_gh);
347 		if (error)
348 			goto out;
349 		error = -EIO;
350 		rgd = gfs2_blk2rgrpd(sdp, ip->i_num.no_addr);
351 		if (!rgd)
352 			goto out_norgrp;
353 		error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &rg_gh);
354 		if (error)
355 			goto out_norgrp;
356 
357 		gfs2_unlink_di(&ip->i_inode); /* mark inode unlinked */
358 		gfs2_glock_dq_uninit(&rg_gh);
359 out_norgrp:
360 		gfs2_glock_dq_uninit(&ri_gh);
361 	}
362 out:
363 	return error;
364 }
365 
366 struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
367 {
368 	struct qstr qstr;
369 	gfs2_str2qstr(&qstr, name);
370 	return gfs2_lookupi(dip, &qstr, 1, NULL);
371 }
372 
373 
374 /**
375  * gfs2_lookupi - Look up a filename in a directory and return its inode
376  * @d_gh: An initialized holder for the directory glock
377  * @name: The name of the inode to look for
378  * @is_root: If 1, ignore the caller's permissions
379  * @i_gh: An uninitialized holder for the new inode glock
380  *
381  * There will always be a vnode (Linux VFS inode) for the d_gh inode unless
382  * @is_root is true.
383  *
384  * Returns: errno
385  */
386 
387 struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
388 			   int is_root, struct nameidata *nd)
389 
390 {
391 	struct super_block *sb = dir->i_sb;
392 	struct gfs2_inode *dip = GFS2_I(dir);
393 	struct gfs2_holder d_gh;
394 	struct gfs2_inum inum;
395 	unsigned int type;
396 	int error = 0;
397 	struct inode *inode = NULL;
398 
399 	if (!name->len || name->len > GFS2_FNAMESIZE)
400 		return ERR_PTR(-ENAMETOOLONG);
401 
402 	if ((name->len == 1 && memcmp(name->name, ".", 1) == 0) ||
403 	    (name->len == 2 && memcmp(name->name, "..", 2) == 0 &&
404 	     dir == sb->s_root->d_inode)) {
405 		igrab(dir);
406 		return dir;
407 	}
408 
409 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
410 	if (error)
411 		return ERR_PTR(error);
412 
413 	if (!is_root) {
414 		error = permission(dir, MAY_EXEC, NULL);
415 		if (error)
416 			goto out;
417 	}
418 
419 	error = gfs2_dir_search(dir, name, &inum, &type);
420 	if (error)
421 		goto out;
422 
423 	inode = gfs2_inode_lookup(sb, &inum, type);
424 
425 out:
426 	gfs2_glock_dq_uninit(&d_gh);
427 	if (error == -ENOENT)
428 		return NULL;
429 	return inode;
430 }
431 
432 static int pick_formal_ino_1(struct gfs2_sbd *sdp, u64 *formal_ino)
433 {
434 	struct gfs2_inode *ip = GFS2_I(sdp->sd_ir_inode);
435 	struct buffer_head *bh;
436 	struct gfs2_inum_range ir;
437 	int error;
438 
439 	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
440 	if (error)
441 		return error;
442 	mutex_lock(&sdp->sd_inum_mutex);
443 
444 	error = gfs2_meta_inode_buffer(ip, &bh);
445 	if (error) {
446 		mutex_unlock(&sdp->sd_inum_mutex);
447 		gfs2_trans_end(sdp);
448 		return error;
449 	}
450 
451 	gfs2_inum_range_in(&ir, bh->b_data + sizeof(struct gfs2_dinode));
452 
453 	if (ir.ir_length) {
454 		*formal_ino = ir.ir_start++;
455 		ir.ir_length--;
456 		gfs2_trans_add_bh(ip->i_gl, bh, 1);
457 		gfs2_inum_range_out(&ir,
458 				    bh->b_data + sizeof(struct gfs2_dinode));
459 		brelse(bh);
460 		mutex_unlock(&sdp->sd_inum_mutex);
461 		gfs2_trans_end(sdp);
462 		return 0;
463 	}
464 
465 	brelse(bh);
466 
467 	mutex_unlock(&sdp->sd_inum_mutex);
468 	gfs2_trans_end(sdp);
469 
470 	return 1;
471 }
472 
473 static int pick_formal_ino_2(struct gfs2_sbd *sdp, u64 *formal_ino)
474 {
475 	struct gfs2_inode *ip = GFS2_I(sdp->sd_ir_inode);
476 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_inum_inode);
477 	struct gfs2_holder gh;
478 	struct buffer_head *bh;
479 	struct gfs2_inum_range ir;
480 	int error;
481 
482 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
483 	if (error)
484 		return error;
485 
486 	error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
487 	if (error)
488 		goto out;
489 	mutex_lock(&sdp->sd_inum_mutex);
490 
491 	error = gfs2_meta_inode_buffer(ip, &bh);
492 	if (error)
493 		goto out_end_trans;
494 
495 	gfs2_inum_range_in(&ir, bh->b_data + sizeof(struct gfs2_dinode));
496 
497 	if (!ir.ir_length) {
498 		struct buffer_head *m_bh;
499 		u64 x, y;
500 
501 		error = gfs2_meta_inode_buffer(m_ip, &m_bh);
502 		if (error)
503 			goto out_brelse;
504 
505 		x = *(u64 *)(m_bh->b_data + sizeof(struct gfs2_dinode));
506 		x = y = be64_to_cpu(x);
507 		ir.ir_start = x;
508 		ir.ir_length = GFS2_INUM_QUANTUM;
509 		x += GFS2_INUM_QUANTUM;
510 		if (x < y)
511 			gfs2_consist_inode(m_ip);
512 		x = cpu_to_be64(x);
513 		gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
514 		*(u64 *)(m_bh->b_data + sizeof(struct gfs2_dinode)) = x;
515 
516 		brelse(m_bh);
517 	}
518 
519 	*formal_ino = ir.ir_start++;
520 	ir.ir_length--;
521 
522 	gfs2_trans_add_bh(ip->i_gl, bh, 1);
523 	gfs2_inum_range_out(&ir, bh->b_data + sizeof(struct gfs2_dinode));
524 
525 out_brelse:
526 	brelse(bh);
527 out_end_trans:
528 	mutex_unlock(&sdp->sd_inum_mutex);
529 	gfs2_trans_end(sdp);
530 out:
531 	gfs2_glock_dq_uninit(&gh);
532 	return error;
533 }
534 
535 static int pick_formal_ino(struct gfs2_sbd *sdp, u64 *inum)
536 {
537 	int error;
538 
539 	error = pick_formal_ino_1(sdp, inum);
540 	if (error <= 0)
541 		return error;
542 
543 	error = pick_formal_ino_2(sdp, inum);
544 
545 	return error;
546 }
547 
548 /**
549  * create_ok - OK to create a new on-disk inode here?
550  * @dip:  Directory in which dinode is to be created
551  * @name:  Name of new dinode
552  * @mode:
553  *
554  * Returns: errno
555  */
556 
557 static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
558 		     unsigned int mode)
559 {
560 	int error;
561 
562 	error = permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, NULL);
563 	if (error)
564 		return error;
565 
566 	/*  Don't create entries in an unlinked directory  */
567 	if (!dip->i_di.di_nlink)
568 		return -EPERM;
569 
570 	error = gfs2_dir_search(&dip->i_inode, name, NULL, NULL);
571 	switch (error) {
572 	case -ENOENT:
573 		error = 0;
574 		break;
575 	case 0:
576 		return -EEXIST;
577 	default:
578 		return error;
579 	}
580 
581 	if (dip->i_di.di_entries == (u32)-1)
582 		return -EFBIG;
583 	if (S_ISDIR(mode) && dip->i_di.di_nlink == (u32)-1)
584 		return -EMLINK;
585 
586 	return 0;
587 }
588 
589 static void munge_mode_uid_gid(struct gfs2_inode *dip, unsigned int *mode,
590 			       unsigned int *uid, unsigned int *gid)
591 {
592 	if (GFS2_SB(&dip->i_inode)->sd_args.ar_suiddir &&
593 	    (dip->i_di.di_mode & S_ISUID) && dip->i_di.di_uid) {
594 		if (S_ISDIR(*mode))
595 			*mode |= S_ISUID;
596 		else if (dip->i_di.di_uid != current->fsuid)
597 			*mode &= ~07111;
598 		*uid = dip->i_di.di_uid;
599 	} else
600 		*uid = current->fsuid;
601 
602 	if (dip->i_di.di_mode & S_ISGID) {
603 		if (S_ISDIR(*mode))
604 			*mode |= S_ISGID;
605 		*gid = dip->i_di.di_gid;
606 	} else
607 		*gid = current->fsgid;
608 }
609 
610 static int alloc_dinode(struct gfs2_inode *dip, struct gfs2_inum *inum,
611 			u64 *generation)
612 {
613 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
614 	int error;
615 
616 	gfs2_alloc_get(dip);
617 
618 	dip->i_alloc.al_requested = RES_DINODE;
619 	error = gfs2_inplace_reserve(dip);
620 	if (error)
621 		goto out;
622 
623 	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS, 0);
624 	if (error)
625 		goto out_ipreserv;
626 
627 	inum->no_addr = gfs2_alloc_di(dip, generation);
628 
629 	gfs2_trans_end(sdp);
630 
631 out_ipreserv:
632 	gfs2_inplace_release(dip);
633 out:
634 	gfs2_alloc_put(dip);
635 	return error;
636 }
637 
638 /**
639  * init_dinode - Fill in a new dinode structure
640  * @dip: the directory this inode is being created in
641  * @gl: The glock covering the new inode
642  * @inum: the inode number
643  * @mode: the file permissions
644  * @uid:
645  * @gid:
646  *
647  */
648 
649 static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
650 			const struct gfs2_inum *inum, unsigned int mode,
651 			unsigned int uid, unsigned int gid,
652 			const u64 *generation)
653 {
654 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
655 	struct gfs2_dinode *di;
656 	struct buffer_head *dibh;
657 
658 	dibh = gfs2_meta_new(gl, inum->no_addr);
659 	gfs2_trans_add_bh(gl, dibh, 1);
660 	gfs2_metatype_set(dibh, GFS2_METATYPE_DI, GFS2_FORMAT_DI);
661 	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
662 	di = (struct gfs2_dinode *)dibh->b_data;
663 
664 	di->di_num.no_formal_ino = cpu_to_be64(inum->no_formal_ino);
665 	di->di_num.no_addr = cpu_to_be64(inum->no_addr);
666 	di->di_mode = cpu_to_be32(mode);
667 	di->di_uid = cpu_to_be32(uid);
668 	di->di_gid = cpu_to_be32(gid);
669 	di->di_nlink = cpu_to_be32(0);
670 	di->di_size = cpu_to_be64(0);
671 	di->di_blocks = cpu_to_be64(1);
672 	di->di_atime = di->di_mtime = di->di_ctime = cpu_to_be64(get_seconds());
673 	di->di_major = di->di_minor = cpu_to_be32(0);
674 	di->di_goal_meta = di->di_goal_data = cpu_to_be64(inum->no_addr);
675 	di->di_generation = cpu_to_be64(*generation);
676 	di->di_flags = cpu_to_be32(0);
677 
678 	if (S_ISREG(mode)) {
679 		if ((dip->i_di.di_flags & GFS2_DIF_INHERIT_JDATA) ||
680 		    gfs2_tune_get(sdp, gt_new_files_jdata))
681 			di->di_flags |= cpu_to_be32(GFS2_DIF_JDATA);
682 		if ((dip->i_di.di_flags & GFS2_DIF_INHERIT_DIRECTIO) ||
683 		    gfs2_tune_get(sdp, gt_new_files_directio))
684 			di->di_flags |= cpu_to_be32(GFS2_DIF_DIRECTIO);
685 	} else if (S_ISDIR(mode)) {
686 		di->di_flags |= cpu_to_be32(dip->i_di.di_flags &
687 					    GFS2_DIF_INHERIT_DIRECTIO);
688 		di->di_flags |= cpu_to_be32(dip->i_di.di_flags &
689 					    GFS2_DIF_INHERIT_JDATA);
690 	}
691 
692 	di->__pad1 = 0;
693 	di->di_payload_format = cpu_to_be32(0);
694 	di->di_height = cpu_to_be32(0);
695 	di->__pad2 = 0;
696 	di->__pad3 = 0;
697 	di->di_depth = cpu_to_be16(0);
698 	di->di_entries = cpu_to_be32(0);
699 	memset(&di->__pad4, 0, sizeof(di->__pad4));
700 	di->di_eattr = cpu_to_be64(0);
701 	memset(&di->di_reserved, 0, sizeof(di->di_reserved));
702 
703 	brelse(dibh);
704 }
705 
706 static int make_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
707 		       unsigned int mode, const struct gfs2_inum *inum,
708 		       const u64 *generation)
709 {
710 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
711 	unsigned int uid, gid;
712 	int error;
713 
714 	munge_mode_uid_gid(dip, &mode, &uid, &gid);
715 	gfs2_alloc_get(dip);
716 
717 	error = gfs2_quota_lock(dip, uid, gid);
718 	if (error)
719 		goto out;
720 
721 	error = gfs2_quota_check(dip, uid, gid);
722 	if (error)
723 		goto out_quota;
724 
725 	error = gfs2_trans_begin(sdp, RES_DINODE + RES_QUOTA, 0);
726 	if (error)
727 		goto out_quota;
728 
729 	init_dinode(dip, gl, inum, mode, uid, gid, generation);
730 	gfs2_quota_change(dip, +1, uid, gid);
731 	gfs2_trans_end(sdp);
732 
733 out_quota:
734 	gfs2_quota_unlock(dip);
735 out:
736 	gfs2_alloc_put(dip);
737 	return error;
738 }
739 
740 static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
741 		       struct gfs2_inode *ip)
742 {
743 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
744 	struct gfs2_alloc *al;
745 	int alloc_required;
746 	struct buffer_head *dibh;
747 	int error;
748 
749 	al = gfs2_alloc_get(dip);
750 
751 	error = gfs2_quota_lock(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
752 	if (error)
753 		goto fail;
754 
755 	error = alloc_required = gfs2_diradd_alloc_required(&dip->i_inode, name);
756 	if (alloc_required < 0)
757 		goto fail;
758 	if (alloc_required) {
759 		error = gfs2_quota_check(dip, dip->i_di.di_uid,
760 					 dip->i_di.di_gid);
761 		if (error)
762 			goto fail_quota_locks;
763 
764 		al->al_requested = sdp->sd_max_dirres;
765 
766 		error = gfs2_inplace_reserve(dip);
767 		if (error)
768 			goto fail_quota_locks;
769 
770 		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
771 					 al->al_rgd->rd_ri.ri_length +
772 					 2 * RES_DINODE +
773 					 RES_STATFS + RES_QUOTA, 0);
774 		if (error)
775 			goto fail_ipreserv;
776 	} else {
777 		error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
778 		if (error)
779 			goto fail_quota_locks;
780 	}
781 
782 	error = gfs2_dir_add(&dip->i_inode, name, &ip->i_num, IF2DT(ip->i_di.di_mode));
783 	if (error)
784 		goto fail_end_trans;
785 
786 	error = gfs2_meta_inode_buffer(ip, &dibh);
787 	if (error)
788 		goto fail_end_trans;
789 	ip->i_di.di_nlink = 1;
790 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
791 	gfs2_dinode_out(&ip->i_di, dibh->b_data);
792 	brelse(dibh);
793 	return 0;
794 
795 fail_end_trans:
796 	gfs2_trans_end(sdp);
797 
798 fail_ipreserv:
799 	if (dip->i_alloc.al_rgd)
800 		gfs2_inplace_release(dip);
801 
802 fail_quota_locks:
803 	gfs2_quota_unlock(dip);
804 
805 fail:
806 	gfs2_alloc_put(dip);
807 	return error;
808 }
809 
810 /**
811  * gfs2_createi - Create a new inode
812  * @ghs: An array of two holders
813  * @name: The name of the new file
814  * @mode: the permissions on the new inode
815  *
816  * @ghs[0] is an initialized holder for the directory
817  * @ghs[1] is the holder for the inode lock
818  *
819  * If the return value is not NULL, the glocks on both the directory and the new
820  * file are held.  A transaction has been started and an inplace reservation
821  * is held, as well.
822  *
823  * Returns: An inode
824  */
825 
826 struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
827 			   unsigned int mode)
828 {
829 	struct inode *inode;
830 	struct gfs2_inode *dip = ghs->gh_gl->gl_object;
831 	struct inode *dir = &dip->i_inode;
832 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
833 	struct gfs2_inum inum;
834 	int error;
835 	u64 generation;
836 
837 	if (!name->len || name->len > GFS2_FNAMESIZE)
838 		return ERR_PTR(-ENAMETOOLONG);
839 
840 	gfs2_holder_reinit(LM_ST_EXCLUSIVE, 0, ghs);
841 	error = gfs2_glock_nq(ghs);
842 	if (error)
843 		goto fail;
844 
845 	error = create_ok(dip, name, mode);
846 	if (error)
847 		goto fail_gunlock;
848 
849 	error = pick_formal_ino(sdp, &inum.no_formal_ino);
850 	if (error)
851 		goto fail_gunlock;
852 
853 	error = alloc_dinode(dip, &inum, &generation);
854 	if (error)
855 		goto fail_gunlock;
856 
857 	if (inum.no_addr < dip->i_num.no_addr) {
858 		gfs2_glock_dq(ghs);
859 
860 		error = gfs2_glock_nq_num(sdp, inum.no_addr,
861 					  &gfs2_inode_glops, LM_ST_EXCLUSIVE,
862 					  GL_SKIP, ghs + 1);
863 		if (error) {
864 			return ERR_PTR(error);
865 		}
866 
867 		gfs2_holder_reinit(LM_ST_EXCLUSIVE, 0, ghs);
868 		error = gfs2_glock_nq(ghs);
869 		if (error) {
870 			gfs2_glock_dq_uninit(ghs + 1);
871 			return ERR_PTR(error);
872 		}
873 
874 		error = create_ok(dip, name, mode);
875 		if (error)
876 			goto fail_gunlock2;
877 	} else {
878 		error = gfs2_glock_nq_num(sdp, inum.no_addr,
879 					  &gfs2_inode_glops, LM_ST_EXCLUSIVE,
880 					  GL_SKIP, ghs + 1);
881 		if (error)
882 			goto fail_gunlock;
883 	}
884 
885 	error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation);
886 	if (error)
887 		goto fail_gunlock2;
888 
889 	inode = gfs2_inode_lookup(dir->i_sb, &inum, IF2DT(mode));
890 	if (IS_ERR(inode))
891 		goto fail_gunlock2;
892 
893 	error = gfs2_inode_refresh(GFS2_I(inode));
894 	if (error)
895 		goto fail_iput;
896 
897 	error = gfs2_acl_create(dip, GFS2_I(inode));
898 	if (error)
899 		goto fail_iput;
900 
901 	error = link_dinode(dip, name, GFS2_I(inode));
902 	if (error)
903 		goto fail_iput;
904 
905 	if (!inode)
906 		return ERR_PTR(-ENOMEM);
907 	return inode;
908 
909 fail_iput:
910 	iput(inode);
911 fail_gunlock2:
912 	gfs2_glock_dq_uninit(ghs + 1);
913 fail_gunlock:
914 	gfs2_glock_dq(ghs);
915 fail:
916 	return ERR_PTR(error);
917 }
918 
919 /**
920  * gfs2_rmdiri - Remove a directory
921  * @dip: The parent directory of the directory to be removed
922  * @name: The name of the directory to be removed
923  * @ip: The GFS2 inode of the directory to be removed
924  *
925  * Assumes Glocks on dip and ip are held
926  *
927  * Returns: errno
928  */
929 
930 int gfs2_rmdiri(struct gfs2_inode *dip, const struct qstr *name,
931 		struct gfs2_inode *ip)
932 {
933 	struct qstr dotname;
934 	int error;
935 
936 	if (ip->i_di.di_entries != 2) {
937 		if (gfs2_consist_inode(ip))
938 			gfs2_dinode_print(&ip->i_di);
939 		return -EIO;
940 	}
941 
942 	error = gfs2_dir_del(dip, name);
943 	if (error)
944 		return error;
945 
946 	error = gfs2_change_nlink(dip, -1);
947 	if (error)
948 		return error;
949 
950 	gfs2_str2qstr(&dotname, ".");
951 	error = gfs2_dir_del(ip, &dotname);
952 	if (error)
953 		return error;
954 
955 	gfs2_str2qstr(&dotname, "..");
956 	error = gfs2_dir_del(ip, &dotname);
957 	if (error)
958 		return error;
959 
960 	error = gfs2_change_nlink(ip, -2);
961 	if (error)
962 		return error;
963 
964 	return error;
965 }
966 
967 /*
968  * gfs2_unlink_ok - check to see that a inode is still in a directory
969  * @dip: the directory
970  * @name: the name of the file
971  * @ip: the inode
972  *
973  * Assumes that the lock on (at least) @dip is held.
974  *
975  * Returns: 0 if the parent/child relationship is correct, errno if it isn't
976  */
977 
978 int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
979 		   struct gfs2_inode *ip)
980 {
981 	struct gfs2_inum inum;
982 	unsigned int type;
983 	int error;
984 
985 	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
986 		return -EPERM;
987 
988 	if ((dip->i_di.di_mode & S_ISVTX) &&
989 	    dip->i_di.di_uid != current->fsuid &&
990 	    ip->i_di.di_uid != current->fsuid && !capable(CAP_FOWNER))
991 		return -EPERM;
992 
993 	if (IS_APPEND(&dip->i_inode))
994 		return -EPERM;
995 
996 	error = permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, NULL);
997 	if (error)
998 		return error;
999 
1000 	error = gfs2_dir_search(&dip->i_inode, name, &inum, &type);
1001 	if (error)
1002 		return error;
1003 
1004 	if (!gfs2_inum_equal(&inum, &ip->i_num))
1005 		return -ENOENT;
1006 
1007 	if (IF2DT(ip->i_di.di_mode) != type) {
1008 		gfs2_consist_inode(dip);
1009 		return -EIO;
1010 	}
1011 
1012 	return 0;
1013 }
1014 
1015 /*
1016  * gfs2_ok_to_move - check if it's ok to move a directory to another directory
1017  * @this: move this
1018  * @to: to here
1019  *
1020  * Follow @to back to the root and make sure we don't encounter @this
1021  * Assumes we already hold the rename lock.
1022  *
1023  * Returns: errno
1024  */
1025 
1026 int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
1027 {
1028 	struct inode *dir = &to->i_inode;
1029 	struct super_block *sb = dir->i_sb;
1030 	struct inode *tmp;
1031 	struct qstr dotdot;
1032 	int error = 0;
1033 
1034 	gfs2_str2qstr(&dotdot, "..");
1035 
1036 	igrab(dir);
1037 
1038 	for (;;) {
1039 		if (dir == &this->i_inode) {
1040 			error = -EINVAL;
1041 			break;
1042 		}
1043 		if (dir == sb->s_root->d_inode) {
1044 			error = 0;
1045 			break;
1046 		}
1047 
1048 		tmp = gfs2_lookupi(dir, &dotdot, 1, NULL);
1049 		if (IS_ERR(tmp)) {
1050 			error = PTR_ERR(tmp);
1051 			break;
1052 		}
1053 
1054 		iput(dir);
1055 		dir = tmp;
1056 	}
1057 
1058 	iput(dir);
1059 
1060 	return error;
1061 }
1062 
1063 /**
1064  * gfs2_readlinki - return the contents of a symlink
1065  * @ip: the symlink's inode
1066  * @buf: a pointer to the buffer to be filled
1067  * @len: a pointer to the length of @buf
1068  *
1069  * If @buf is too small, a piece of memory is kmalloc()ed and needs
1070  * to be freed by the caller.
1071  *
1072  * Returns: errno
1073  */
1074 
1075 int gfs2_readlinki(struct gfs2_inode *ip, char **buf, unsigned int *len)
1076 {
1077 	struct gfs2_holder i_gh;
1078 	struct buffer_head *dibh;
1079 	unsigned int x;
1080 	int error;
1081 
1082 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
1083 	error = gfs2_glock_nq_atime(&i_gh);
1084 	if (error) {
1085 		gfs2_holder_uninit(&i_gh);
1086 		return error;
1087 	}
1088 
1089 	if (!ip->i_di.di_size) {
1090 		gfs2_consist_inode(ip);
1091 		error = -EIO;
1092 		goto out;
1093 	}
1094 
1095 	error = gfs2_meta_inode_buffer(ip, &dibh);
1096 	if (error)
1097 		goto out;
1098 
1099 	x = ip->i_di.di_size + 1;
1100 	if (x > *len) {
1101 		*buf = kmalloc(x, GFP_KERNEL);
1102 		if (!*buf) {
1103 			error = -ENOMEM;
1104 			goto out_brelse;
1105 		}
1106 	}
1107 
1108 	memcpy(*buf, dibh->b_data + sizeof(struct gfs2_dinode), x);
1109 	*len = x;
1110 
1111 out_brelse:
1112 	brelse(dibh);
1113 out:
1114 	gfs2_glock_dq_uninit(&i_gh);
1115 	return error;
1116 }
1117 
1118 /**
1119  * gfs2_glock_nq_atime - Acquire a hold on an inode's glock, and
1120  *       conditionally update the inode's atime
1121  * @gh: the holder to acquire
1122  *
1123  * Tests atime (access time) for gfs2_read, gfs2_readdir and gfs2_mmap
1124  * Update if the difference between the current time and the inode's current
1125  * atime is greater than an interval specified at mount.
1126  *
1127  * Returns: errno
1128  */
1129 
1130 int gfs2_glock_nq_atime(struct gfs2_holder *gh)
1131 {
1132 	struct gfs2_glock *gl = gh->gh_gl;
1133 	struct gfs2_sbd *sdp = gl->gl_sbd;
1134 	struct gfs2_inode *ip = gl->gl_object;
1135 	s64 curtime, quantum = gfs2_tune_get(sdp, gt_atime_quantum);
1136 	unsigned int state;
1137 	int flags;
1138 	int error;
1139 
1140 	if (gfs2_assert_warn(sdp, gh->gh_flags & GL_ATIME) ||
1141 	    gfs2_assert_warn(sdp, !(gh->gh_flags & GL_ASYNC)) ||
1142 	    gfs2_assert_warn(sdp, gl->gl_ops == &gfs2_inode_glops))
1143 		return -EINVAL;
1144 
1145 	state = gh->gh_state;
1146 	flags = gh->gh_flags;
1147 
1148 	error = gfs2_glock_nq(gh);
1149 	if (error)
1150 		return error;
1151 
1152 	if (test_bit(SDF_NOATIME, &sdp->sd_flags) ||
1153 	    (sdp->sd_vfs->s_flags & MS_RDONLY))
1154 		return 0;
1155 
1156 	curtime = get_seconds();
1157 	if (curtime - ip->i_di.di_atime >= quantum) {
1158 		gfs2_glock_dq(gh);
1159 		gfs2_holder_reinit(LM_ST_EXCLUSIVE, gh->gh_flags & ~LM_FLAG_ANY,
1160 				   gh);
1161 		error = gfs2_glock_nq(gh);
1162 		if (error)
1163 			return error;
1164 
1165 		/* Verify that atime hasn't been updated while we were
1166 		   trying to get exclusive lock. */
1167 
1168 		curtime = get_seconds();
1169 		if (curtime - ip->i_di.di_atime >= quantum) {
1170 			struct buffer_head *dibh;
1171 
1172 			error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1173 			if (error == -EROFS)
1174 				return 0;
1175 			if (error)
1176 				goto fail;
1177 
1178 			error = gfs2_meta_inode_buffer(ip, &dibh);
1179 			if (error)
1180 				goto fail_end_trans;
1181 
1182 			ip->i_di.di_atime = curtime;
1183 
1184 			gfs2_trans_add_bh(ip->i_gl, dibh, 1);
1185 			gfs2_dinode_out(&ip->i_di, dibh->b_data);
1186 			brelse(dibh);
1187 
1188 			gfs2_trans_end(sdp);
1189 		}
1190 
1191 		/* If someone else has asked for the glock,
1192 		   unlock and let them have it. Then reacquire
1193 		   in the original state. */
1194 		if (gfs2_glock_is_blocking(gl)) {
1195 			gfs2_glock_dq(gh);
1196 			gfs2_holder_reinit(state, flags, gh);
1197 			return gfs2_glock_nq(gh);
1198 		}
1199 	}
1200 
1201 	return 0;
1202 
1203 fail_end_trans:
1204 	gfs2_trans_end(sdp);
1205 fail:
1206 	gfs2_glock_dq(gh);
1207 	return error;
1208 }
1209 
1210 /**
1211  * glock_compare_atime - Compare two struct gfs2_glock structures for sort
1212  * @arg_a: the first structure
1213  * @arg_b: the second structure
1214  *
1215  * Returns: 1 if A > B
1216  *         -1 if A < B
1217  *          0 if A == B
1218  */
1219 
1220 static int glock_compare_atime(const void *arg_a, const void *arg_b)
1221 {
1222 	const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1223 	const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1224 	const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1225 	const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1226 
1227 	if (a->ln_number > b->ln_number)
1228 		return 1;
1229 	if (a->ln_number < b->ln_number)
1230 		return -1;
1231 	if (gh_a->gh_state == LM_ST_SHARED && gh_b->gh_state == LM_ST_EXCLUSIVE)
1232 		return 1;
1233 	if (gh_a->gh_state == LM_ST_SHARED && (gh_b->gh_flags & GL_ATIME))
1234 		return 1;
1235 
1236 	return 0;
1237 }
1238 
1239 /**
1240  * gfs2_glock_nq_m_atime - acquire multiple glocks where one may need an
1241  *      atime update
1242  * @num_gh: the number of structures
1243  * @ghs: an array of struct gfs2_holder structures
1244  *
1245  * Returns: 0 on success (all glocks acquired),
1246  *          errno on failure (no glocks acquired)
1247  */
1248 
1249 int gfs2_glock_nq_m_atime(unsigned int num_gh, struct gfs2_holder *ghs)
1250 {
1251 	struct gfs2_holder **p;
1252 	unsigned int x;
1253 	int error = 0;
1254 
1255 	if (!num_gh)
1256 		return 0;
1257 
1258 	if (num_gh == 1) {
1259 		ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1260 		if (ghs->gh_flags & GL_ATIME)
1261 			error = gfs2_glock_nq_atime(ghs);
1262 		else
1263 			error = gfs2_glock_nq(ghs);
1264 		return error;
1265 	}
1266 
1267 	p = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL);
1268 	if (!p)
1269 		return -ENOMEM;
1270 
1271 	for (x = 0; x < num_gh; x++)
1272 		p[x] = &ghs[x];
1273 
1274 	sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare_atime,NULL);
1275 
1276 	for (x = 0; x < num_gh; x++) {
1277 		p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1278 
1279 		if (p[x]->gh_flags & GL_ATIME)
1280 			error = gfs2_glock_nq_atime(p[x]);
1281 		else
1282 			error = gfs2_glock_nq(p[x]);
1283 
1284 		if (error) {
1285 			while (x--)
1286 				gfs2_glock_dq(p[x]);
1287 			break;
1288 		}
1289 	}
1290 
1291 	kfree(p);
1292 	return error;
1293 }
1294 
1295 
1296 static int
1297 __gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr)
1298 {
1299 	struct buffer_head *dibh;
1300 	int error;
1301 
1302 	error = gfs2_meta_inode_buffer(ip, &dibh);
1303 	if (!error) {
1304 		error = inode_setattr(&ip->i_inode, attr);
1305 		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
1306 		gfs2_inode_attr_out(ip);
1307 
1308 		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
1309 		gfs2_dinode_out(&ip->i_di, dibh->b_data);
1310 		brelse(dibh);
1311 	}
1312 	return error;
1313 }
1314 
1315 /**
1316  * gfs2_setattr_simple -
1317  * @ip:
1318  * @attr:
1319  *
1320  * Called with a reference on the vnode.
1321  *
1322  * Returns: errno
1323  */
1324 
1325 int gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr)
1326 {
1327 	int error;
1328 
1329 	if (current->journal_info)
1330 		return __gfs2_setattr_simple(ip, attr);
1331 
1332 	error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE, 0);
1333 	if (error)
1334 		return error;
1335 
1336 	error = __gfs2_setattr_simple(ip, attr);
1337 	gfs2_trans_end(GFS2_SB(&ip->i_inode));
1338 	return error;
1339 }
1340 
1341