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  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_shared.h"
  9#include "xfs_format.h"
 10#include "xfs_log_format.h"
 11#include "xfs_trans_resv.h"
 12#include "xfs_mount.h"
 13#include "xfs_inode.h"
 14#include "xfs_trans.h"
 15#include "xfs_bmap.h"
 16#include "xfs_dir2.h"
 17#include "xfs_dir2_priv.h"
 18#include "xfs_errortag.h"
 19#include "xfs_error.h"
 20#include "xfs_trace.h"
 21
 22struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
 23
 24/*
 25 * Convert inode mode to directory entry filetype
 26 */
 27unsigned char
 28xfs_mode_to_ftype(
 29	int		mode)
 30{
 31	switch (mode & S_IFMT) {
 32	case S_IFREG:
 33		return XFS_DIR3_FT_REG_FILE;
 34	case S_IFDIR:
 35		return XFS_DIR3_FT_DIR;
 36	case S_IFCHR:
 37		return XFS_DIR3_FT_CHRDEV;
 38	case S_IFBLK:
 39		return XFS_DIR3_FT_BLKDEV;
 40	case S_IFIFO:
 41		return XFS_DIR3_FT_FIFO;
 42	case S_IFSOCK:
 43		return XFS_DIR3_FT_SOCK;
 44	case S_IFLNK:
 45		return XFS_DIR3_FT_SYMLINK;
 46	default:
 47		return XFS_DIR3_FT_UNKNOWN;
 48	}
 49}
 50
 51/*
 52 * ASCII case-insensitive (ie. A-Z) support for directories that was
 53 * used in IRIX.
 54 */
 55STATIC xfs_dahash_t
 56xfs_ascii_ci_hashname(
 57	struct xfs_name	*name)
 58{
 59	xfs_dahash_t	hash;
 60	int		i;
 61
 62	for (i = 0, hash = 0; i < name->len; i++)
 63		hash = tolower(name->name[i]) ^ rol32(hash, 7);
 64
 65	return hash;
 66}
 67
 68STATIC enum xfs_dacmp
 69xfs_ascii_ci_compname(
 70	struct xfs_da_args *args,
 71	const unsigned char *name,
 72	int		len)
 73{
 74	enum xfs_dacmp	result;
 75	int		i;
 76
 77	if (args->namelen != len)
 78		return XFS_CMP_DIFFERENT;
 79
 80	result = XFS_CMP_EXACT;
 81	for (i = 0; i < len; i++) {
 82		if (args->name[i] == name[i])
 83			continue;
 84		if (tolower(args->name[i]) != tolower(name[i]))
 85			return XFS_CMP_DIFFERENT;
 86		result = XFS_CMP_CASE;
 87	}
 88
 89	return result;
 90}
 91
 92static const struct xfs_nameops xfs_ascii_ci_nameops = {
 93	.hashname	= xfs_ascii_ci_hashname,
 94	.compname	= xfs_ascii_ci_compname,
 95};
 96
 97int
 98xfs_da_mount(
 99	struct xfs_mount	*mp)
100{
101	struct xfs_da_geometry	*dageo;
102	int			nodehdr_size;
103
104
105	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
106	ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE);
107
108	mp->m_dir_inode_ops = xfs_dir_get_ops(mp, NULL);
109	mp->m_nondir_inode_ops = xfs_nondir_get_ops(mp, NULL);
110
111	nodehdr_size = mp->m_dir_inode_ops->node_hdr_size;
112	mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
113				    KM_MAYFAIL);
114	mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
115				     KM_MAYFAIL);
116	if (!mp->m_dir_geo || !mp->m_attr_geo) {
117		kmem_free(mp->m_dir_geo);
118		kmem_free(mp->m_attr_geo);
119		return -ENOMEM;
120	}
121
122	/* set up directory geometry */
123	dageo = mp->m_dir_geo;
124	dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
125	dageo->fsblog = mp->m_sb.sb_blocklog;
126	dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb);
127	dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
128
129	/*
130	 * Now we've set up the block conversion variables, we can calculate the
131	 * segment block constants using the geometry structure.
132	 */
133	dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
134	dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
135	dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
136	dageo->node_ents = (dageo->blksize - nodehdr_size) /
137				(uint)sizeof(xfs_da_node_entry_t);
138	dageo->magicpct = (dageo->blksize * 37) / 100;
139
140	/* set up attribute geometry - single fsb only */
141	dageo = mp->m_attr_geo;
142	dageo->blklog = mp->m_sb.sb_blocklog;
143	dageo->fsblog = mp->m_sb.sb_blocklog;
144	dageo->blksize = 1 << dageo->blklog;
145	dageo->fsbcount = 1;
146	dageo->node_ents = (dageo->blksize - nodehdr_size) /
147				(uint)sizeof(xfs_da_node_entry_t);
148	dageo->magicpct = (dageo->blksize * 37) / 100;
149
150	if (xfs_sb_version_hasasciici(&mp->m_sb))
151		mp->m_dirnameops = &xfs_ascii_ci_nameops;
152	else
153		mp->m_dirnameops = &xfs_default_nameops;
154
155	return 0;
156}
157
158void
159xfs_da_unmount(
160	struct xfs_mount	*mp)
161{
162	kmem_free(mp->m_dir_geo);
163	kmem_free(mp->m_attr_geo);
164}
165
166/*
167 * Return 1 if directory contains only "." and "..".
168 */
169int
170xfs_dir_isempty(
171	xfs_inode_t	*dp)
172{
173	xfs_dir2_sf_hdr_t	*sfp;
174
175	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
176	if (dp->i_d.di_size == 0)	/* might happen during shutdown. */
177		return 1;
178	if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
179		return 0;
180	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
181	return !sfp->count;
182}
183
184/*
185 * Validate a given inode number.
186 */
187int
188xfs_dir_ino_validate(
189	xfs_mount_t	*mp,
190	xfs_ino_t	ino)
191{
192	bool		ino_ok = xfs_verify_dir_ino(mp, ino);
193
194	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE))) {
195		xfs_warn(mp, "Invalid inode number 0x%Lx",
196				(unsigned long long) ino);
197		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
198		return -EFSCORRUPTED;
199	}
200	return 0;
201}
202
203/*
204 * Initialize a directory with its "." and ".." entries.
205 */
206int
207xfs_dir_init(
208	xfs_trans_t	*tp,
209	xfs_inode_t	*dp,
210	xfs_inode_t	*pdp)
211{
212	struct xfs_da_args *args;
213	int		error;
214
215	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
216	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
217	if (error)
218		return error;
219
220	args = kmem_zalloc(sizeof(*args), KM_NOFS);
221	if (!args)
222		return -ENOMEM;
223
224	args->geo = dp->i_mount->m_dir_geo;
225	args->dp = dp;
226	args->trans = tp;
227	error = xfs_dir2_sf_create(args, pdp->i_ino);
228	kmem_free(args);
229	return error;
230}
231
232/*
233 * Enter a name in a directory, or check for available space.
234 * If inum is 0, only the available space test is performed.
235 */
236int
237xfs_dir_createname(
238	struct xfs_trans	*tp,
239	struct xfs_inode	*dp,
240	struct xfs_name		*name,
241	xfs_ino_t		inum,		/* new entry inode number */
242	xfs_extlen_t		total)		/* bmap's total block count */
243{
244	struct xfs_da_args	*args;
245	int			rval;
246	int			v;		/* type-checking value */
247
248	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
249
250	if (inum) {
251		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
252		if (rval)
253			return rval;
254		XFS_STATS_INC(dp->i_mount, xs_dir_create);
255	}
256
257	args = kmem_zalloc(sizeof(*args), KM_NOFS);
258	if (!args)
259		return -ENOMEM;
260
261	args->geo = dp->i_mount->m_dir_geo;
262	args->name = name->name;
263	args->namelen = name->len;
264	args->filetype = name->type;
265	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
266	args->inumber = inum;
267	args->dp = dp;
268	args->total = total;
269	args->whichfork = XFS_DATA_FORK;
270	args->trans = tp;
271	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
272	if (!inum)
273		args->op_flags |= XFS_DA_OP_JUSTCHECK;
274
275	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
276		rval = xfs_dir2_sf_addname(args);
277		goto out_free;
278	}
279
280	rval = xfs_dir2_isblock(args, &v);
281	if (rval)
282		goto out_free;
283	if (v) {
284		rval = xfs_dir2_block_addname(args);
285		goto out_free;
286	}
287
288	rval = xfs_dir2_isleaf(args, &v);
289	if (rval)
290		goto out_free;
291	if (v)
292		rval = xfs_dir2_leaf_addname(args);
293	else
294		rval = xfs_dir2_node_addname(args);
295
296out_free:
297	kmem_free(args);
298	return rval;
299}
300
301/*
302 * If doing a CI lookup and case-insensitive match, dup actual name into
303 * args.value. Return EEXIST for success (ie. name found) or an error.
304 */
305int
306xfs_dir_cilookup_result(
307	struct xfs_da_args *args,
308	const unsigned char *name,
309	int		len)
310{
311	if (args->cmpresult == XFS_CMP_DIFFERENT)
312		return -ENOENT;
313	if (args->cmpresult != XFS_CMP_CASE ||
314					!(args->op_flags & XFS_DA_OP_CILOOKUP))
315		return -EEXIST;
316
317	args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
318	if (!args->value)
319		return -ENOMEM;
320
321	memcpy(args->value, name, len);
322	args->valuelen = len;
323	return -EEXIST;
324}
325
326/*
327 * Lookup a name in a directory, give back the inode number.
328 * If ci_name is not NULL, returns the actual name in ci_name if it differs
329 * to name, or ci_name->name is set to NULL for an exact match.
330 */
331
332int
333xfs_dir_lookup(
334	xfs_trans_t	*tp,
335	xfs_inode_t	*dp,
336	struct xfs_name	*name,
337	xfs_ino_t	*inum,		/* out: inode number */
338	struct xfs_name *ci_name)	/* out: actual name if CI match */
339{
340	struct xfs_da_args *args;
341	int		rval;
342	int		v;		/* type-checking value */
343	int		lock_mode;
344
345	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
346	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
347
348	/*
349	 * We need to use KM_NOFS here so that lockdep will not throw false
350	 * positive deadlock warnings on a non-transactional lookup path. It is
351	 * safe to recurse into inode recalim in that case, but lockdep can't
352	 * easily be taught about it. Hence KM_NOFS avoids having to add more
353	 * lockdep Doing this avoids having to add a bunch of lockdep class
354	 * annotations into the reclaim path for the ilock.
355	 */
356	args = kmem_zalloc(sizeof(*args), KM_NOFS);
357	args->geo = dp->i_mount->m_dir_geo;
358	args->name = name->name;
359	args->namelen = name->len;
360	args->filetype = name->type;
361	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
362	args->dp = dp;
363	args->whichfork = XFS_DATA_FORK;
364	args->trans = tp;
365	args->op_flags = XFS_DA_OP_OKNOENT;
366	if (ci_name)
367		args->op_flags |= XFS_DA_OP_CILOOKUP;
368
369	lock_mode = xfs_ilock_data_map_shared(dp);
370	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
371		rval = xfs_dir2_sf_lookup(args);
372		goto out_check_rval;
373	}
374
375	rval = xfs_dir2_isblock(args, &v);
376	if (rval)
377		goto out_free;
378	if (v) {
379		rval = xfs_dir2_block_lookup(args);
380		goto out_check_rval;
381	}
382
383	rval = xfs_dir2_isleaf(args, &v);
384	if (rval)
385		goto out_free;
386	if (v)
387		rval = xfs_dir2_leaf_lookup(args);
388	else
389		rval = xfs_dir2_node_lookup(args);
390
391out_check_rval:
392	if (rval == -EEXIST)
393		rval = 0;
394	if (!rval) {
395		*inum = args->inumber;
396		if (ci_name) {
397			ci_name->name = args->value;
398			ci_name->len = args->valuelen;
399		}
400	}
401out_free:
402	xfs_iunlock(dp, lock_mode);
403	kmem_free(args);
404	return rval;
405}
406
407/*
408 * Remove an entry from a directory.
409 */
410int
411xfs_dir_removename(
412	struct xfs_trans	*tp,
413	struct xfs_inode	*dp,
414	struct xfs_name		*name,
415	xfs_ino_t		ino,
416	xfs_extlen_t		total)		/* bmap's total block count */
417{
418	struct xfs_da_args	*args;
419	int			rval;
420	int			v;		/* type-checking value */
421
422	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
423	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
424
425	args = kmem_zalloc(sizeof(*args), KM_NOFS);
426	if (!args)
427		return -ENOMEM;
428
429	args->geo = dp->i_mount->m_dir_geo;
430	args->name = name->name;
431	args->namelen = name->len;
432	args->filetype = name->type;
433	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
434	args->inumber = ino;
435	args->dp = dp;
436	args->total = total;
437	args->whichfork = XFS_DATA_FORK;
438	args->trans = tp;
439
440	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
441		rval = xfs_dir2_sf_removename(args);
442		goto out_free;
443	}
444
445	rval = xfs_dir2_isblock(args, &v);
446	if (rval)
447		goto out_free;
448	if (v) {
449		rval = xfs_dir2_block_removename(args);
450		goto out_free;
451	}
452
453	rval = xfs_dir2_isleaf(args, &v);
454	if (rval)
455		goto out_free;
456	if (v)
457		rval = xfs_dir2_leaf_removename(args);
458	else
459		rval = xfs_dir2_node_removename(args);
460out_free:
461	kmem_free(args);
462	return rval;
463}
464
465/*
466 * Replace the inode number of a directory entry.
467 */
468int
469xfs_dir_replace(
470	struct xfs_trans	*tp,
471	struct xfs_inode	*dp,
472	struct xfs_name		*name,		/* name of entry to replace */
473	xfs_ino_t		inum,		/* new inode number */
474	xfs_extlen_t		total)		/* bmap's total block count */
475{
476	struct xfs_da_args	*args;
477	int			rval;
478	int			v;		/* type-checking value */
479
480	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
481
482	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
483	if (rval)
484		return rval;
485
486	args = kmem_zalloc(sizeof(*args), KM_NOFS);
487	if (!args)
488		return -ENOMEM;
489
490	args->geo = dp->i_mount->m_dir_geo;
491	args->name = name->name;
492	args->namelen = name->len;
493	args->filetype = name->type;
494	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
495	args->inumber = inum;
496	args->dp = dp;
497	args->total = total;
498	args->whichfork = XFS_DATA_FORK;
499	args->trans = tp;
500
501	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
502		rval = xfs_dir2_sf_replace(args);
503		goto out_free;
504	}
505
506	rval = xfs_dir2_isblock(args, &v);
507	if (rval)
508		goto out_free;
509	if (v) {
510		rval = xfs_dir2_block_replace(args);
511		goto out_free;
512	}
513
514	rval = xfs_dir2_isleaf(args, &v);
515	if (rval)
516		goto out_free;
517	if (v)
518		rval = xfs_dir2_leaf_replace(args);
519	else
520		rval = xfs_dir2_node_replace(args);
521out_free:
522	kmem_free(args);
523	return rval;
524}
525
526/*
527 * See if this entry can be added to the directory without allocating space.
528 */
529int
530xfs_dir_canenter(
531	xfs_trans_t	*tp,
532	xfs_inode_t	*dp,
533	struct xfs_name	*name)		/* name of entry to add */
534{
535	return xfs_dir_createname(tp, dp, name, 0, 0);
536}
537
538/*
539 * Utility routines.
540 */
541
542/*
543 * Add a block to the directory.
544 *
545 * This routine is for data and free blocks, not leaf/node blocks which are
546 * handled by xfs_da_grow_inode.
547 */
548int
549xfs_dir2_grow_inode(
550	struct xfs_da_args	*args,
551	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
552	xfs_dir2_db_t		*dbp)	/* out: block number added */
553{
554	struct xfs_inode	*dp = args->dp;
555	struct xfs_mount	*mp = dp->i_mount;
556	xfs_fileoff_t		bno;	/* directory offset of new block */
557	int			count;	/* count of filesystem blocks */
558	int			error;
559
560	trace_xfs_dir2_grow_inode(args, space);
561
562	/*
563	 * Set lowest possible block in the space requested.
564	 */
565	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
566	count = args->geo->fsbcount;
567
568	error = xfs_da_grow_inode_int(args, &bno, count);
569	if (error)
570		return error;
571
572	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
573
574	/*
575	 * Update file's size if this is the data space and it grew.
576	 */
577	if (space == XFS_DIR2_DATA_SPACE) {
578		xfs_fsize_t	size;		/* directory file (data) size */
579
580		size = XFS_FSB_TO_B(mp, bno + count);
581		if (size > dp->i_d.di_size) {
582			dp->i_d.di_size = size;
583			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
584		}
585	}
586	return 0;
587}
588
589/*
590 * See if the directory is a single-block form directory.
591 */
592int
593xfs_dir2_isblock(
594	struct xfs_da_args	*args,
595	int			*vp)	/* out: 1 is block, 0 is not block */
596{
597	xfs_fileoff_t		last;	/* last file offset */
598	int			rval;
599
600	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
601		return rval;
602	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
603	if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
604		return -EFSCORRUPTED;
605	*vp = rval;
606	return 0;
607}
608
609/*
610 * See if the directory is a single-leaf form directory.
611 */
612int
613xfs_dir2_isleaf(
614	struct xfs_da_args	*args,
615	int			*vp)	/* out: 1 is block, 0 is not block */
616{
617	xfs_fileoff_t		last;	/* last file offset */
618	int			rval;
619
620	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
621		return rval;
622	*vp = last == args->geo->leafblk + args->geo->fsbcount;
623	return 0;
624}
625
626/*
627 * Remove the given block from the directory.
628 * This routine is used for data and free blocks, leaf/node are done
629 * by xfs_da_shrink_inode.
630 */
631int
632xfs_dir2_shrink_inode(
633	struct xfs_da_args	*args,
634	xfs_dir2_db_t		db,
635	struct xfs_buf		*bp)
636{
637	xfs_fileoff_t		bno;		/* directory file offset */
638	xfs_dablk_t		da;		/* directory file offset */
639	int			done;		/* bunmap is finished */
640	struct xfs_inode	*dp;
641	int			error;
642	struct xfs_mount	*mp;
643	struct xfs_trans	*tp;
644
645	trace_xfs_dir2_shrink_inode(args, db);
646
647	dp = args->dp;
648	mp = dp->i_mount;
649	tp = args->trans;
650	da = xfs_dir2_db_to_da(args->geo, db);
651
652	/* Unmap the fsblock(s). */
653	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &done);
654	if (error) {
655		/*
656		 * ENOSPC actually can happen if we're in a removename with no
657		 * space reservation, and the resulting block removal would
658		 * cause a bmap btree split or conversion from extents to btree.
659		 * This can only happen for un-fragmented directory blocks,
660		 * since you need to be punching out the middle of an extent.
661		 * In this case we need to leave the block in the file, and not
662		 * binval it.  So the block has to be in a consistent empty
663		 * state and appropriately logged.  We don't free up the buffer,
664		 * the caller can tell it hasn't happened since it got an error
665		 * back.
666		 */
667		return error;
668	}
669	ASSERT(done);
670	/*
671	 * Invalidate the buffer from the transaction.
672	 */
673	xfs_trans_binval(tp, bp);
674	/*
675	 * If it's not a data block, we're done.
676	 */
677	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
678		return 0;
679	/*
680	 * If the block isn't the last one in the directory, we're done.
681	 */
682	if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
683		return 0;
684	bno = da;
685	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
686		/*
687		 * This can't really happen unless there's kernel corruption.
688		 */
689		return error;
690	}
691	if (db == args->geo->datablk)
692		ASSERT(bno == 0);
693	else
694		ASSERT(bno > 0);
695	/*
696	 * Set the size to the new last block.
697	 */
698	dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
699	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
700	return 0;
701}
702
703/* Returns true if the directory entry name is valid. */
704bool
705xfs_dir2_namecheck(
706	const void	*name,
707	size_t		length)
708{
709	/*
710	 * MAXNAMELEN includes the trailing null, but (name/length) leave it
711	 * out, so use >= for the length check.
712	 */
713	if (length >= MAXNAMELEN)
714		return false;
715
716	/* There shouldn't be any slashes or nulls here */
717	return !memchr(name, '/', length) && !memchr(name, 0, length);
718}