xref: /openbmc/linux/fs/xfs/libxfs/xfs_dir2.c (revision b9b77222)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_format.h"
9 #include "xfs_log_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_defer.h"
13 #include "xfs_da_format.h"
14 #include "xfs_da_btree.h"
15 #include "xfs_inode.h"
16 #include "xfs_trans.h"
17 #include "xfs_inode_item.h"
18 #include "xfs_bmap.h"
19 #include "xfs_dir2.h"
20 #include "xfs_dir2_priv.h"
21 #include "xfs_ialloc.h"
22 #include "xfs_errortag.h"
23 #include "xfs_error.h"
24 #include "xfs_trace.h"
25 
26 struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
27 
28 /*
29  * Convert inode mode to directory entry filetype
30  */
31 unsigned char
32 xfs_mode_to_ftype(
33 	int		mode)
34 {
35 	switch (mode & S_IFMT) {
36 	case S_IFREG:
37 		return XFS_DIR3_FT_REG_FILE;
38 	case S_IFDIR:
39 		return XFS_DIR3_FT_DIR;
40 	case S_IFCHR:
41 		return XFS_DIR3_FT_CHRDEV;
42 	case S_IFBLK:
43 		return XFS_DIR3_FT_BLKDEV;
44 	case S_IFIFO:
45 		return XFS_DIR3_FT_FIFO;
46 	case S_IFSOCK:
47 		return XFS_DIR3_FT_SOCK;
48 	case S_IFLNK:
49 		return XFS_DIR3_FT_SYMLINK;
50 	default:
51 		return XFS_DIR3_FT_UNKNOWN;
52 	}
53 }
54 
55 /*
56  * ASCII case-insensitive (ie. A-Z) support for directories that was
57  * used in IRIX.
58  */
59 STATIC xfs_dahash_t
60 xfs_ascii_ci_hashname(
61 	struct xfs_name	*name)
62 {
63 	xfs_dahash_t	hash;
64 	int		i;
65 
66 	for (i = 0, hash = 0; i < name->len; i++)
67 		hash = tolower(name->name[i]) ^ rol32(hash, 7);
68 
69 	return hash;
70 }
71 
72 STATIC enum xfs_dacmp
73 xfs_ascii_ci_compname(
74 	struct xfs_da_args *args,
75 	const unsigned char *name,
76 	int		len)
77 {
78 	enum xfs_dacmp	result;
79 	int		i;
80 
81 	if (args->namelen != len)
82 		return XFS_CMP_DIFFERENT;
83 
84 	result = XFS_CMP_EXACT;
85 	for (i = 0; i < len; i++) {
86 		if (args->name[i] == name[i])
87 			continue;
88 		if (tolower(args->name[i]) != tolower(name[i]))
89 			return XFS_CMP_DIFFERENT;
90 		result = XFS_CMP_CASE;
91 	}
92 
93 	return result;
94 }
95 
96 static const struct xfs_nameops xfs_ascii_ci_nameops = {
97 	.hashname	= xfs_ascii_ci_hashname,
98 	.compname	= xfs_ascii_ci_compname,
99 };
100 
101 int
102 xfs_da_mount(
103 	struct xfs_mount	*mp)
104 {
105 	struct xfs_da_geometry	*dageo;
106 	int			nodehdr_size;
107 
108 
109 	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
110 	ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE);
111 
112 	mp->m_dir_inode_ops = xfs_dir_get_ops(mp, NULL);
113 	mp->m_nondir_inode_ops = xfs_nondir_get_ops(mp, NULL);
114 
115 	nodehdr_size = mp->m_dir_inode_ops->node_hdr_size;
116 	mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
117 				    KM_SLEEP | KM_MAYFAIL);
118 	mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
119 				     KM_SLEEP | KM_MAYFAIL);
120 	if (!mp->m_dir_geo || !mp->m_attr_geo) {
121 		kmem_free(mp->m_dir_geo);
122 		kmem_free(mp->m_attr_geo);
123 		return -ENOMEM;
124 	}
125 
126 	/* set up directory geometry */
127 	dageo = mp->m_dir_geo;
128 	dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
129 	dageo->fsblog = mp->m_sb.sb_blocklog;
130 	dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb);
131 	dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
132 
133 	/*
134 	 * Now we've set up the block conversion variables, we can calculate the
135 	 * segment block constants using the geometry structure.
136 	 */
137 	dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
138 	dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
139 	dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
140 	dageo->node_ents = (dageo->blksize - nodehdr_size) /
141 				(uint)sizeof(xfs_da_node_entry_t);
142 	dageo->magicpct = (dageo->blksize * 37) / 100;
143 
144 	/* set up attribute geometry - single fsb only */
145 	dageo = mp->m_attr_geo;
146 	dageo->blklog = mp->m_sb.sb_blocklog;
147 	dageo->fsblog = mp->m_sb.sb_blocklog;
148 	dageo->blksize = 1 << dageo->blklog;
149 	dageo->fsbcount = 1;
150 	dageo->node_ents = (dageo->blksize - nodehdr_size) /
151 				(uint)sizeof(xfs_da_node_entry_t);
152 	dageo->magicpct = (dageo->blksize * 37) / 100;
153 
154 	if (xfs_sb_version_hasasciici(&mp->m_sb))
155 		mp->m_dirnameops = &xfs_ascii_ci_nameops;
156 	else
157 		mp->m_dirnameops = &xfs_default_nameops;
158 
159 	return 0;
160 }
161 
162 void
163 xfs_da_unmount(
164 	struct xfs_mount	*mp)
165 {
166 	kmem_free(mp->m_dir_geo);
167 	kmem_free(mp->m_attr_geo);
168 }
169 
170 /*
171  * Return 1 if directory contains only "." and "..".
172  */
173 int
174 xfs_dir_isempty(
175 	xfs_inode_t	*dp)
176 {
177 	xfs_dir2_sf_hdr_t	*sfp;
178 
179 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
180 	if (dp->i_d.di_size == 0)	/* might happen during shutdown. */
181 		return 1;
182 	if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
183 		return 0;
184 	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
185 	return !sfp->count;
186 }
187 
188 /*
189  * Validate a given inode number.
190  */
191 int
192 xfs_dir_ino_validate(
193 	xfs_mount_t	*mp,
194 	xfs_ino_t	ino)
195 {
196 	bool		ino_ok = xfs_verify_dir_ino(mp, ino);
197 
198 	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE))) {
199 		xfs_warn(mp, "Invalid inode number 0x%Lx",
200 				(unsigned long long) ino);
201 		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
202 		return -EFSCORRUPTED;
203 	}
204 	return 0;
205 }
206 
207 /*
208  * Initialize a directory with its "." and ".." entries.
209  */
210 int
211 xfs_dir_init(
212 	xfs_trans_t	*tp,
213 	xfs_inode_t	*dp,
214 	xfs_inode_t	*pdp)
215 {
216 	struct xfs_da_args *args;
217 	int		error;
218 
219 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
220 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
221 	if (error)
222 		return error;
223 
224 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
225 	if (!args)
226 		return -ENOMEM;
227 
228 	args->geo = dp->i_mount->m_dir_geo;
229 	args->dp = dp;
230 	args->trans = tp;
231 	error = xfs_dir2_sf_create(args, pdp->i_ino);
232 	kmem_free(args);
233 	return error;
234 }
235 
236 /*
237  * Enter a name in a directory, or check for available space.
238  * If inum is 0, only the available space test is performed.
239  */
240 int
241 xfs_dir_createname(
242 	xfs_trans_t		*tp,
243 	xfs_inode_t		*dp,
244 	struct xfs_name		*name,
245 	xfs_ino_t		inum,		/* new entry inode number */
246 	xfs_fsblock_t		*first,		/* bmap's firstblock */
247 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
248 	xfs_extlen_t		total)		/* bmap's total block count */
249 {
250 	struct xfs_da_args	*args;
251 	int			rval;
252 	int			v;		/* type-checking value */
253 
254 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
255 	if (inum) {
256 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
257 		if (rval)
258 			return rval;
259 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
260 	}
261 
262 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
263 	if (!args)
264 		return -ENOMEM;
265 
266 	args->geo = dp->i_mount->m_dir_geo;
267 	args->name = name->name;
268 	args->namelen = name->len;
269 	args->filetype = name->type;
270 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
271 	args->inumber = inum;
272 	args->dp = dp;
273 	args->firstblock = first;
274 	args->dfops = dfops;
275 	args->total = total;
276 	args->whichfork = XFS_DATA_FORK;
277 	args->trans = tp;
278 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
279 	if (!inum)
280 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
281 
282 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
283 		rval = xfs_dir2_sf_addname(args);
284 		goto out_free;
285 	}
286 
287 	rval = xfs_dir2_isblock(args, &v);
288 	if (rval)
289 		goto out_free;
290 	if (v) {
291 		rval = xfs_dir2_block_addname(args);
292 		goto out_free;
293 	}
294 
295 	rval = xfs_dir2_isleaf(args, &v);
296 	if (rval)
297 		goto out_free;
298 	if (v)
299 		rval = xfs_dir2_leaf_addname(args);
300 	else
301 		rval = xfs_dir2_node_addname(args);
302 
303 out_free:
304 	kmem_free(args);
305 	return rval;
306 }
307 
308 /*
309  * If doing a CI lookup and case-insensitive match, dup actual name into
310  * args.value. Return EEXIST for success (ie. name found) or an error.
311  */
312 int
313 xfs_dir_cilookup_result(
314 	struct xfs_da_args *args,
315 	const unsigned char *name,
316 	int		len)
317 {
318 	if (args->cmpresult == XFS_CMP_DIFFERENT)
319 		return -ENOENT;
320 	if (args->cmpresult != XFS_CMP_CASE ||
321 					!(args->op_flags & XFS_DA_OP_CILOOKUP))
322 		return -EEXIST;
323 
324 	args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
325 	if (!args->value)
326 		return -ENOMEM;
327 
328 	memcpy(args->value, name, len);
329 	args->valuelen = len;
330 	return -EEXIST;
331 }
332 
333 /*
334  * Lookup a name in a directory, give back the inode number.
335  * If ci_name is not NULL, returns the actual name in ci_name if it differs
336  * to name, or ci_name->name is set to NULL for an exact match.
337  */
338 
339 int
340 xfs_dir_lookup(
341 	xfs_trans_t	*tp,
342 	xfs_inode_t	*dp,
343 	struct xfs_name	*name,
344 	xfs_ino_t	*inum,		/* out: inode number */
345 	struct xfs_name *ci_name)	/* out: actual name if CI match */
346 {
347 	struct xfs_da_args *args;
348 	int		rval;
349 	int		v;		/* type-checking value */
350 	int		lock_mode;
351 
352 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
353 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
354 
355 	/*
356 	 * We need to use KM_NOFS here so that lockdep will not throw false
357 	 * positive deadlock warnings on a non-transactional lookup path. It is
358 	 * safe to recurse into inode recalim in that case, but lockdep can't
359 	 * easily be taught about it. Hence KM_NOFS avoids having to add more
360 	 * lockdep Doing this avoids having to add a bunch of lockdep class
361 	 * annotations into the reclaim path for the ilock.
362 	 */
363 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
364 	args->geo = dp->i_mount->m_dir_geo;
365 	args->name = name->name;
366 	args->namelen = name->len;
367 	args->filetype = name->type;
368 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
369 	args->dp = dp;
370 	args->whichfork = XFS_DATA_FORK;
371 	args->trans = tp;
372 	args->op_flags = XFS_DA_OP_OKNOENT;
373 	if (ci_name)
374 		args->op_flags |= XFS_DA_OP_CILOOKUP;
375 
376 	lock_mode = xfs_ilock_data_map_shared(dp);
377 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
378 		rval = xfs_dir2_sf_lookup(args);
379 		goto out_check_rval;
380 	}
381 
382 	rval = xfs_dir2_isblock(args, &v);
383 	if (rval)
384 		goto out_free;
385 	if (v) {
386 		rval = xfs_dir2_block_lookup(args);
387 		goto out_check_rval;
388 	}
389 
390 	rval = xfs_dir2_isleaf(args, &v);
391 	if (rval)
392 		goto out_free;
393 	if (v)
394 		rval = xfs_dir2_leaf_lookup(args);
395 	else
396 		rval = xfs_dir2_node_lookup(args);
397 
398 out_check_rval:
399 	if (rval == -EEXIST)
400 		rval = 0;
401 	if (!rval) {
402 		*inum = args->inumber;
403 		if (ci_name) {
404 			ci_name->name = args->value;
405 			ci_name->len = args->valuelen;
406 		}
407 	}
408 out_free:
409 	xfs_iunlock(dp, lock_mode);
410 	kmem_free(args);
411 	return rval;
412 }
413 
414 /*
415  * Remove an entry from a directory.
416  */
417 int
418 xfs_dir_removename(
419 	xfs_trans_t	*tp,
420 	xfs_inode_t	*dp,
421 	struct xfs_name	*name,
422 	xfs_ino_t	ino,
423 	xfs_fsblock_t	*first,		/* bmap's firstblock */
424 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
425 	xfs_extlen_t	total)		/* bmap's total block count */
426 {
427 	struct xfs_da_args *args;
428 	int		rval;
429 	int		v;		/* type-checking value */
430 
431 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
432 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
433 
434 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
435 	if (!args)
436 		return -ENOMEM;
437 
438 	args->geo = dp->i_mount->m_dir_geo;
439 	args->name = name->name;
440 	args->namelen = name->len;
441 	args->filetype = name->type;
442 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
443 	args->inumber = ino;
444 	args->dp = dp;
445 	args->firstblock = first;
446 	args->dfops = dfops;
447 	args->total = total;
448 	args->whichfork = XFS_DATA_FORK;
449 	args->trans = tp;
450 
451 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
452 		rval = xfs_dir2_sf_removename(args);
453 		goto out_free;
454 	}
455 
456 	rval = xfs_dir2_isblock(args, &v);
457 	if (rval)
458 		goto out_free;
459 	if (v) {
460 		rval = xfs_dir2_block_removename(args);
461 		goto out_free;
462 	}
463 
464 	rval = xfs_dir2_isleaf(args, &v);
465 	if (rval)
466 		goto out_free;
467 	if (v)
468 		rval = xfs_dir2_leaf_removename(args);
469 	else
470 		rval = xfs_dir2_node_removename(args);
471 out_free:
472 	kmem_free(args);
473 	return rval;
474 }
475 
476 /*
477  * Replace the inode number of a directory entry.
478  */
479 int
480 xfs_dir_replace(
481 	xfs_trans_t	*tp,
482 	xfs_inode_t	*dp,
483 	struct xfs_name	*name,		/* name of entry to replace */
484 	xfs_ino_t	inum,		/* new inode number */
485 	xfs_fsblock_t	*first,		/* bmap's firstblock */
486 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
487 	xfs_extlen_t	total)		/* bmap's total block count */
488 {
489 	struct xfs_da_args *args;
490 	int		rval;
491 	int		v;		/* type-checking value */
492 
493 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
494 
495 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
496 	if (rval)
497 		return rval;
498 
499 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
500 	if (!args)
501 		return -ENOMEM;
502 
503 	args->geo = dp->i_mount->m_dir_geo;
504 	args->name = name->name;
505 	args->namelen = name->len;
506 	args->filetype = name->type;
507 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
508 	args->inumber = inum;
509 	args->dp = dp;
510 	args->firstblock = first;
511 	args->dfops = dfops;
512 	args->total = total;
513 	args->whichfork = XFS_DATA_FORK;
514 	args->trans = tp;
515 
516 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
517 		rval = xfs_dir2_sf_replace(args);
518 		goto out_free;
519 	}
520 
521 	rval = xfs_dir2_isblock(args, &v);
522 	if (rval)
523 		goto out_free;
524 	if (v) {
525 		rval = xfs_dir2_block_replace(args);
526 		goto out_free;
527 	}
528 
529 	rval = xfs_dir2_isleaf(args, &v);
530 	if (rval)
531 		goto out_free;
532 	if (v)
533 		rval = xfs_dir2_leaf_replace(args);
534 	else
535 		rval = xfs_dir2_node_replace(args);
536 out_free:
537 	kmem_free(args);
538 	return rval;
539 }
540 
541 /*
542  * See if this entry can be added to the directory without allocating space.
543  */
544 int
545 xfs_dir_canenter(
546 	xfs_trans_t	*tp,
547 	xfs_inode_t	*dp,
548 	struct xfs_name	*name)		/* name of entry to add */
549 {
550 	return xfs_dir_createname(tp, dp, name, 0, NULL, NULL, 0);
551 }
552 
553 /*
554  * Utility routines.
555  */
556 
557 /*
558  * Add a block to the directory.
559  *
560  * This routine is for data and free blocks, not leaf/node blocks which are
561  * handled by xfs_da_grow_inode.
562  */
563 int
564 xfs_dir2_grow_inode(
565 	struct xfs_da_args	*args,
566 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
567 	xfs_dir2_db_t		*dbp)	/* out: block number added */
568 {
569 	struct xfs_inode	*dp = args->dp;
570 	struct xfs_mount	*mp = dp->i_mount;
571 	xfs_fileoff_t		bno;	/* directory offset of new block */
572 	int			count;	/* count of filesystem blocks */
573 	int			error;
574 
575 	trace_xfs_dir2_grow_inode(args, space);
576 
577 	/*
578 	 * Set lowest possible block in the space requested.
579 	 */
580 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
581 	count = args->geo->fsbcount;
582 
583 	error = xfs_da_grow_inode_int(args, &bno, count);
584 	if (error)
585 		return error;
586 
587 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
588 
589 	/*
590 	 * Update file's size if this is the data space and it grew.
591 	 */
592 	if (space == XFS_DIR2_DATA_SPACE) {
593 		xfs_fsize_t	size;		/* directory file (data) size */
594 
595 		size = XFS_FSB_TO_B(mp, bno + count);
596 		if (size > dp->i_d.di_size) {
597 			dp->i_d.di_size = size;
598 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
599 		}
600 	}
601 	return 0;
602 }
603 
604 /*
605  * See if the directory is a single-block form directory.
606  */
607 int
608 xfs_dir2_isblock(
609 	struct xfs_da_args	*args,
610 	int			*vp)	/* out: 1 is block, 0 is not block */
611 {
612 	xfs_fileoff_t		last;	/* last file offset */
613 	int			rval;
614 
615 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
616 		return rval;
617 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
618 	if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
619 		return -EFSCORRUPTED;
620 	*vp = rval;
621 	return 0;
622 }
623 
624 /*
625  * See if the directory is a single-leaf form directory.
626  */
627 int
628 xfs_dir2_isleaf(
629 	struct xfs_da_args	*args,
630 	int			*vp)	/* out: 1 is block, 0 is not block */
631 {
632 	xfs_fileoff_t		last;	/* last file offset */
633 	int			rval;
634 
635 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
636 		return rval;
637 	*vp = last == args->geo->leafblk + args->geo->fsbcount;
638 	return 0;
639 }
640 
641 /*
642  * Remove the given block from the directory.
643  * This routine is used for data and free blocks, leaf/node are done
644  * by xfs_da_shrink_inode.
645  */
646 int
647 xfs_dir2_shrink_inode(
648 	xfs_da_args_t	*args,
649 	xfs_dir2_db_t	db,
650 	struct xfs_buf	*bp)
651 {
652 	xfs_fileoff_t	bno;		/* directory file offset */
653 	xfs_dablk_t	da;		/* directory file offset */
654 	int		done;		/* bunmap is finished */
655 	xfs_inode_t	*dp;
656 	int		error;
657 	xfs_mount_t	*mp;
658 	xfs_trans_t	*tp;
659 
660 	trace_xfs_dir2_shrink_inode(args, db);
661 
662 	dp = args->dp;
663 	mp = dp->i_mount;
664 	tp = args->trans;
665 	da = xfs_dir2_db_to_da(args->geo, db);
666 
667 	/* Unmap the fsblock(s). */
668 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0,
669 			    args->firstblock, args->dfops, &done);
670 	if (error) {
671 		/*
672 		 * ENOSPC actually can happen if we're in a removename with no
673 		 * space reservation, and the resulting block removal would
674 		 * cause a bmap btree split or conversion from extents to btree.
675 		 * This can only happen for un-fragmented directory blocks,
676 		 * since you need to be punching out the middle of an extent.
677 		 * In this case we need to leave the block in the file, and not
678 		 * binval it.  So the block has to be in a consistent empty
679 		 * state and appropriately logged.  We don't free up the buffer,
680 		 * the caller can tell it hasn't happened since it got an error
681 		 * back.
682 		 */
683 		return error;
684 	}
685 	ASSERT(done);
686 	/*
687 	 * Invalidate the buffer from the transaction.
688 	 */
689 	xfs_trans_binval(tp, bp);
690 	/*
691 	 * If it's not a data block, we're done.
692 	 */
693 	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
694 		return 0;
695 	/*
696 	 * If the block isn't the last one in the directory, we're done.
697 	 */
698 	if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
699 		return 0;
700 	bno = da;
701 	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
702 		/*
703 		 * This can't really happen unless there's kernel corruption.
704 		 */
705 		return error;
706 	}
707 	if (db == args->geo->datablk)
708 		ASSERT(bno == 0);
709 	else
710 		ASSERT(bno > 0);
711 	/*
712 	 * Set the size to the new last block.
713 	 */
714 	dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
715 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
716 	return 0;
717 }
718