1/*
2 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_types.h"
21#include "xfs_bit.h"
22#include "xfs_log.h"
23#include "xfs_inum.h"
24#include "xfs_trans.h"
25#include "xfs_sb.h"
26#include "xfs_ag.h"
27#include "xfs_dir2.h"
28#include "xfs_dmapi.h"
29#include "xfs_mount.h"
30#include "xfs_da_btree.h"
31#include "xfs_bmap_btree.h"
32#include "xfs_alloc_btree.h"
33#include "xfs_dir2_sf.h"
34#include "xfs_attr_sf.h"
35#include "xfs_dinode.h"
36#include "xfs_inode.h"
37#include "xfs_inode_item.h"
38#include "xfs_bmap.h"
39#include "xfs_dir2_data.h"
40#include "xfs_dir2_leaf.h"
41#include "xfs_dir2_block.h"
42#include "xfs_dir2_node.h"
43#include "xfs_dir2_trace.h"
44#include "xfs_error.h"
45
46static int	xfs_dir2_put_dirent64_direct(xfs_dir2_put_args_t *pa);
47static int	xfs_dir2_put_dirent64_uio(xfs_dir2_put_args_t *pa);
48
49void
50xfs_dir_mount(
51	xfs_mount_t	*mp)
52{
53	ASSERT(XFS_SB_VERSION_HASDIRV2(&mp->m_sb));
54	ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
55	       XFS_MAX_BLOCKSIZE);
56	mp->m_dirblksize = 1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog);
57	mp->m_dirblkfsbs = 1 << mp->m_sb.sb_dirblklog;
58	mp->m_dirdatablk = XFS_DIR2_DB_TO_DA(mp, XFS_DIR2_DATA_FIRSTDB(mp));
59	mp->m_dirleafblk = XFS_DIR2_DB_TO_DA(mp, XFS_DIR2_LEAF_FIRSTDB(mp));
60	mp->m_dirfreeblk = XFS_DIR2_DB_TO_DA(mp, XFS_DIR2_FREE_FIRSTDB(mp));
61	mp->m_attr_node_ents =
62		(mp->m_sb.sb_blocksize - (uint)sizeof(xfs_da_node_hdr_t)) /
63		(uint)sizeof(xfs_da_node_entry_t);
64	mp->m_dir_node_ents =
65		(mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
66		(uint)sizeof(xfs_da_node_entry_t);
67	mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
68}
69
70/*
71 * Return 1 if directory contains only "." and "..".
72 */
73int
74xfs_dir_isempty(
75	xfs_inode_t	*dp)
76{
77	xfs_dir2_sf_t	*sfp;
78
79	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
80	if (dp->i_d.di_size == 0)	/* might happen during shutdown. */
81		return 1;
82	if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
83		return 0;
84	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
85	return !sfp->hdr.count;
86}
87
88/*
89 * Validate a given inode number.
90 */
91int
92xfs_dir_ino_validate(
93	xfs_mount_t	*mp,
94	xfs_ino_t	ino)
95{
96	xfs_agblock_t	agblkno;
97	xfs_agino_t	agino;
98	xfs_agnumber_t	agno;
99	int		ino_ok;
100	int		ioff;
101
102	agno = XFS_INO_TO_AGNO(mp, ino);
103	agblkno = XFS_INO_TO_AGBNO(mp, ino);
104	ioff = XFS_INO_TO_OFFSET(mp, ino);
105	agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
106	ino_ok =
107		agno < mp->m_sb.sb_agcount &&
108		agblkno < mp->m_sb.sb_agblocks &&
109		agblkno != 0 &&
110		ioff < (1 << mp->m_sb.sb_inopblog) &&
111		XFS_AGINO_TO_INO(mp, agno, agino) == ino;
112	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
113			XFS_RANDOM_DIR_INO_VALIDATE))) {
114		xfs_fs_cmn_err(CE_WARN, mp, "Invalid inode number 0x%Lx",
115				(unsigned long long) ino);
116		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
117		return XFS_ERROR(EFSCORRUPTED);
118	}
119	return 0;
120}
121
122/*
123 * Initialize a directory with its "." and ".." entries.
124 */
125int
126xfs_dir_init(
127	xfs_trans_t	*tp,
128	xfs_inode_t	*dp,
129	xfs_inode_t	*pdp)
130{
131	xfs_da_args_t	args;
132	int		error;
133
134	memset((char *)&args, 0, sizeof(args));
135	args.dp = dp;
136	args.trans = tp;
137	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
138	if ((error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino)))
139		return error;
140	return xfs_dir2_sf_create(&args, pdp->i_ino);
141}
142
143/*
144  Enter a name in a directory.
145 */
146int
147xfs_dir_createname(
148	xfs_trans_t		*tp,
149	xfs_inode_t		*dp,
150	char			*name,
151	int			namelen,
152	xfs_ino_t		inum,		/* new entry inode number */
153	xfs_fsblock_t		*first,		/* bmap's firstblock */
154	xfs_bmap_free_t		*flist,		/* bmap's freeblock list */
155	xfs_extlen_t		total)		/* bmap's total block count */
156{
157	xfs_da_args_t		args;
158	int			rval;
159	int			v;		/* type-checking value */
160
161	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
162	if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
163		return rval;
164	XFS_STATS_INC(xs_dir_create);
165
166	args.name = name;
167	args.namelen = namelen;
168	args.hashval = xfs_da_hashname(name, namelen);
169	args.inumber = inum;
170	args.dp = dp;
171	args.firstblock = first;
172	args.flist = flist;
173	args.total = total;
174	args.whichfork = XFS_DATA_FORK;
175	args.trans = tp;
176	args.justcheck = 0;
177	args.addname = args.oknoent = 1;
178
179	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
180		rval = xfs_dir2_sf_addname(&args);
181	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
182		return rval;
183	else if (v)
184		rval = xfs_dir2_block_addname(&args);
185	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
186		return rval;
187	else if (v)
188		rval = xfs_dir2_leaf_addname(&args);
189	else
190		rval = xfs_dir2_node_addname(&args);
191	return rval;
192}
193
194/*
195 * Lookup a name in a directory, give back the inode number.
196 */
197int
198xfs_dir_lookup(
199	xfs_trans_t	*tp,
200	xfs_inode_t	*dp,
201	char		*name,
202	int		namelen,
203	xfs_ino_t	*inum)		/* out: inode number */
204{
205	xfs_da_args_t	args;
206	int		rval;
207	int		v;		/* type-checking value */
208
209	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
210	XFS_STATS_INC(xs_dir_lookup);
211
212	args.name = name;
213	args.namelen = namelen;
214	args.hashval = xfs_da_hashname(name, namelen);
215	args.inumber = 0;
216	args.dp = dp;
217	args.firstblock = NULL;
218	args.flist = NULL;
219	args.total = 0;
220	args.whichfork = XFS_DATA_FORK;
221	args.trans = tp;
222	args.justcheck = args.addname = 0;
223	args.oknoent = 1;
224
225	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
226		rval = xfs_dir2_sf_lookup(&args);
227	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
228		return rval;
229	else if (v)
230		rval = xfs_dir2_block_lookup(&args);
231	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
232		return rval;
233	else if (v)
234		rval = xfs_dir2_leaf_lookup(&args);
235	else
236		rval = xfs_dir2_node_lookup(&args);
237	if (rval == EEXIST)
238		rval = 0;
239	if (rval == 0)
240		*inum = args.inumber;
241	return rval;
242}
243
244/*
245 * Remove an entry from a directory.
246 */
247int
248xfs_dir_removename(
249	xfs_trans_t	*tp,
250	xfs_inode_t	*dp,
251	char		*name,
252	int		namelen,
253	xfs_ino_t	ino,
254	xfs_fsblock_t	*first,		/* bmap's firstblock */
255	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
256	xfs_extlen_t	total)		/* bmap's total block count */
257{
258	xfs_da_args_t	args;
259	int		rval;
260	int		v;		/* type-checking value */
261
262	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
263	XFS_STATS_INC(xs_dir_remove);
264
265	args.name = name;
266	args.namelen = namelen;
267	args.hashval = xfs_da_hashname(name, namelen);
268	args.inumber = ino;
269	args.dp = dp;
270	args.firstblock = first;
271	args.flist = flist;
272	args.total = total;
273	args.whichfork = XFS_DATA_FORK;
274	args.trans = tp;
275	args.justcheck = args.addname = args.oknoent = 0;
276
277	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
278		rval = xfs_dir2_sf_removename(&args);
279	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
280		return rval;
281	else if (v)
282		rval = xfs_dir2_block_removename(&args);
283	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
284		return rval;
285	else if (v)
286		rval = xfs_dir2_leaf_removename(&args);
287	else
288		rval = xfs_dir2_node_removename(&args);
289	return rval;
290}
291
292/*
293 * Read a directory.
294 */
295int
296xfs_dir_getdents(
297	xfs_trans_t	*tp,
298	xfs_inode_t	*dp,
299	uio_t		*uio,		/* caller's buffer control */
300	int		*eofp)		/* out: eof reached */
301{
302	int		alignment;	/* alignment required for ABI */
303	xfs_dirent_t	*dbp;		/* malloc'ed buffer */
304	xfs_dir2_put_t	put;		/* entry formatting routine */
305	int		rval;		/* return value */
306	int		v;		/* type-checking value */
307
308	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
309	XFS_STATS_INC(xs_dir_getdents);
310	/*
311	 * If our caller has given us a single contiguous aligned memory buffer,
312	 * just work directly within that buffer.  If it's in user memory,
313	 * lock it down first.
314	 */
315	alignment = sizeof(xfs_off_t) - 1;
316	if ((uio->uio_iovcnt == 1) &&
317	    (((__psint_t)uio->uio_iov[0].iov_base & alignment) == 0) &&
318	    ((uio->uio_iov[0].iov_len & alignment) == 0)) {
319		dbp = NULL;
320		put = xfs_dir2_put_dirent64_direct;
321	} else {
322		dbp = kmem_alloc(sizeof(*dbp) + MAXNAMELEN, KM_SLEEP);
323		put = xfs_dir2_put_dirent64_uio;
324	}
325
326	*eofp = 0;
327	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
328		rval = xfs_dir2_sf_getdents(dp, uio, eofp, dbp, put);
329	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
330		;
331	else if (v)
332		rval = xfs_dir2_block_getdents(tp, dp, uio, eofp, dbp, put);
333	else
334		rval = xfs_dir2_leaf_getdents(tp, dp, uio, eofp, dbp, put);
335	if (dbp != NULL)
336		kmem_free(dbp, sizeof(*dbp) + MAXNAMELEN);
337	return rval;
338}
339
340/*
341 * Replace the inode number of a directory entry.
342 */
343int
344xfs_dir_replace(
345	xfs_trans_t	*tp,
346	xfs_inode_t	*dp,
347	char		*name,		/* name of entry to replace */
348	int		namelen,
349	xfs_ino_t	inum,		/* new inode number */
350	xfs_fsblock_t	*first,		/* bmap's firstblock */
351	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
352	xfs_extlen_t	total)		/* bmap's total block count */
353{
354	xfs_da_args_t	args;
355	int		rval;
356	int		v;		/* type-checking value */
357
358	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
359
360	if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
361		return rval;
362
363	args.name = name;
364	args.namelen = namelen;
365	args.hashval = xfs_da_hashname(name, namelen);
366	args.inumber = inum;
367	args.dp = dp;
368	args.firstblock = first;
369	args.flist = flist;
370	args.total = total;
371	args.whichfork = XFS_DATA_FORK;
372	args.trans = tp;
373	args.justcheck = args.addname = args.oknoent = 0;
374
375	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
376		rval = xfs_dir2_sf_replace(&args);
377	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
378		return rval;
379	else if (v)
380		rval = xfs_dir2_block_replace(&args);
381	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
382		return rval;
383	else if (v)
384		rval = xfs_dir2_leaf_replace(&args);
385	else
386		rval = xfs_dir2_node_replace(&args);
387	return rval;
388}
389
390/*
391 * See if this entry can be added to the directory without allocating space.
392 */
393int
394xfs_dir_canenter(
395	xfs_trans_t	*tp,
396	xfs_inode_t	*dp,
397	char		*name,		/* name of entry to add */
398	int		namelen)
399{
400	xfs_da_args_t	args;
401	int		rval;
402	int		v;		/* type-checking value */
403
404	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
405
406	args.name = name;
407	args.namelen = namelen;
408	args.hashval = xfs_da_hashname(name, namelen);
409	args.inumber = 0;
410	args.dp = dp;
411	args.firstblock = NULL;
412	args.flist = NULL;
413	args.total = 0;
414	args.whichfork = XFS_DATA_FORK;
415	args.trans = tp;
416	args.justcheck = args.addname = args.oknoent = 1;
417
418	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
419		rval = xfs_dir2_sf_addname(&args);
420	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
421		return rval;
422	else if (v)
423		rval = xfs_dir2_block_addname(&args);
424	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
425		return rval;
426	else if (v)
427		rval = xfs_dir2_leaf_addname(&args);
428	else
429		rval = xfs_dir2_node_addname(&args);
430	return rval;
431}
432
433/*
434 * Utility routines.
435 */
436
437/*
438 * Add a block to the directory.
439 * This routine is for data and free blocks, not leaf/node blocks
440 * which are handled by xfs_da_grow_inode.
441 */
442int
443xfs_dir2_grow_inode(
444	xfs_da_args_t	*args,
445	int		space,		/* v2 dir's space XFS_DIR2_xxx_SPACE */
446	xfs_dir2_db_t	*dbp)		/* out: block number added */
447{
448	xfs_fileoff_t	bno;		/* directory offset of new block */
449	int		count;		/* count of filesystem blocks */
450	xfs_inode_t	*dp;		/* incore directory inode */
451	int		error;
452	int		got;		/* blocks actually mapped */
453	int		i;
454	xfs_bmbt_irec_t	map;		/* single structure for bmap */
455	int		mapi;		/* mapping index */
456	xfs_bmbt_irec_t	*mapp;		/* bmap mapping structure(s) */
457	xfs_mount_t	*mp;
458	int		nmap;		/* number of bmap entries */
459	xfs_trans_t	*tp;
460
461	xfs_dir2_trace_args_s("grow_inode", args, space);
462	dp = args->dp;
463	tp = args->trans;
464	mp = dp->i_mount;
465	/*
466	 * Set lowest possible block in the space requested.
467	 */
468	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
469	count = mp->m_dirblkfsbs;
470	/*
471	 * Find the first hole for our block.
472	 */
473	if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, XFS_DATA_FORK)))
474		return error;
475	nmap = 1;
476	ASSERT(args->firstblock != NULL);
477	/*
478	 * Try mapping the new block contiguously (one extent).
479	 */
480	if ((error = xfs_bmapi(tp, dp, bno, count,
481			XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
482			args->firstblock, args->total, &map, &nmap,
483			args->flist, NULL)))
484		return error;
485	ASSERT(nmap <= 1);
486	if (nmap == 1) {
487		mapp = &map;
488		mapi = 1;
489	}
490	/*
491	 * Didn't work and this is a multiple-fsb directory block.
492	 * Try again with contiguous flag turned on.
493	 */
494	else if (nmap == 0 && count > 1) {
495		xfs_fileoff_t	b;	/* current file offset */
496
497		/*
498		 * Space for maximum number of mappings.
499		 */
500		mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
501		/*
502		 * Iterate until we get to the end of our block.
503		 */
504		for (b = bno, mapi = 0; b < bno + count; ) {
505			int	c;	/* current fsb count */
506
507			/*
508			 * Can't map more than MAX_NMAP at once.
509			 */
510			nmap = MIN(XFS_BMAP_MAX_NMAP, count);
511			c = (int)(bno + count - b);
512			if ((error = xfs_bmapi(tp, dp, b, c,
513					XFS_BMAPI_WRITE|XFS_BMAPI_METADATA,
514					args->firstblock, args->total,
515					&mapp[mapi], &nmap, args->flist,
516					NULL))) {
517				kmem_free(mapp, sizeof(*mapp) * count);
518				return error;
519			}
520			if (nmap < 1)
521				break;
522			/*
523			 * Add this bunch into our table, go to the next offset.
524			 */
525			mapi += nmap;
526			b = mapp[mapi - 1].br_startoff +
527			    mapp[mapi - 1].br_blockcount;
528		}
529	}
530	/*
531	 * Didn't work.
532	 */
533	else {
534		mapi = 0;
535		mapp = NULL;
536	}
537	/*
538	 * See how many fsb's we got.
539	 */
540	for (i = 0, got = 0; i < mapi; i++)
541		got += mapp[i].br_blockcount;
542	/*
543	 * Didn't get enough fsb's, or the first/last block's are wrong.
544	 */
545	if (got != count || mapp[0].br_startoff != bno ||
546	    mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
547	    bno + count) {
548		if (mapp != &map)
549			kmem_free(mapp, sizeof(*mapp) * count);
550		return XFS_ERROR(ENOSPC);
551	}
552	/*
553	 * Done with the temporary mapping table.
554	 */
555	if (mapp != &map)
556		kmem_free(mapp, sizeof(*mapp) * count);
557	*dbp = XFS_DIR2_DA_TO_DB(mp, (xfs_dablk_t)bno);
558	/*
559	 * Update file's size if this is the data space and it grew.
560	 */
561	if (space == XFS_DIR2_DATA_SPACE) {
562		xfs_fsize_t	size;		/* directory file (data) size */
563
564		size = XFS_FSB_TO_B(mp, bno + count);
565		if (size > dp->i_d.di_size) {
566			dp->i_d.di_size = size;
567			xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
568		}
569	}
570	return 0;
571}
572
573/*
574 * See if the directory is a single-block form directory.
575 */
576int
577xfs_dir2_isblock(
578	xfs_trans_t	*tp,
579	xfs_inode_t	*dp,
580	int		*vp)		/* out: 1 is block, 0 is not block */
581{
582	xfs_fileoff_t	last;		/* last file offset */
583	xfs_mount_t	*mp;
584	int		rval;
585
586	mp = dp->i_mount;
587	if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
588		return rval;
589	rval = XFS_FSB_TO_B(mp, last) == mp->m_dirblksize;
590	ASSERT(rval == 0 || dp->i_d.di_size == mp->m_dirblksize);
591	*vp = rval;
592	return 0;
593}
594
595/*
596 * See if the directory is a single-leaf form directory.
597 */
598int
599xfs_dir2_isleaf(
600	xfs_trans_t	*tp,
601	xfs_inode_t	*dp,
602	int		*vp)		/* out: 1 is leaf, 0 is not leaf */
603{
604	xfs_fileoff_t	last;		/* last file offset */
605	xfs_mount_t	*mp;
606	int		rval;
607
608	mp = dp->i_mount;
609	if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
610		return rval;
611	*vp = last == mp->m_dirleafblk + (1 << mp->m_sb.sb_dirblklog);
612	return 0;
613}
614
615/*
616 * Getdents put routine for 64-bit ABI, direct form.
617 */
618static int
619xfs_dir2_put_dirent64_direct(
620	xfs_dir2_put_args_t	*pa)
621{
622	xfs_dirent_t		*idbp;		/* dirent pointer */
623	iovec_t			*iovp;		/* io vector */
624	int			namelen;	/* entry name length */
625	int			reclen;		/* entry total length */
626	uio_t			*uio;		/* I/O control */
627
628	namelen = pa->namelen;
629	reclen = DIRENTSIZE(namelen);
630	uio = pa->uio;
631	/*
632	 * Won't fit in the remaining space.
633	 */
634	if (reclen > uio->uio_resid) {
635		pa->done = 0;
636		return 0;
637	}
638	iovp = uio->uio_iov;
639	idbp = (xfs_dirent_t *)iovp->iov_base;
640	iovp->iov_base = (char *)idbp + reclen;
641	iovp->iov_len -= reclen;
642	uio->uio_resid -= reclen;
643	idbp->d_reclen = reclen;
644	idbp->d_ino = pa->ino;
645	idbp->d_off = pa->cook;
646	idbp->d_name[namelen] = '\0';
647	pa->done = 1;
648	memcpy(idbp->d_name, pa->name, namelen);
649	return 0;
650}
651
652/*
653 * Getdents put routine for 64-bit ABI, uio form.
654 */
655static int
656xfs_dir2_put_dirent64_uio(
657	xfs_dir2_put_args_t	*pa)
658{
659	xfs_dirent_t		*idbp;		/* dirent pointer */
660	int			namelen;	/* entry name length */
661	int			reclen;		/* entry total length */
662	int			rval;		/* return value */
663	uio_t			*uio;		/* I/O control */
664
665	namelen = pa->namelen;
666	reclen = DIRENTSIZE(namelen);
667	uio = pa->uio;
668	/*
669	 * Won't fit in the remaining space.
670	 */
671	if (reclen > uio->uio_resid) {
672		pa->done = 0;
673		return 0;
674	}
675	idbp = pa->dbp;
676	idbp->d_reclen = reclen;
677	idbp->d_ino = pa->ino;
678	idbp->d_off = pa->cook;
679	idbp->d_name[namelen] = '\0';
680	memcpy(idbp->d_name, pa->name, namelen);
681	rval = xfs_uio_read((caddr_t)idbp, reclen, uio);
682	pa->done = (rval == 0);
683	return rval;
684}
685
686/*
687 * Remove the given block from the directory.
688 * This routine is used for data and free blocks, leaf/node are done
689 * by xfs_da_shrink_inode.
690 */
691int
692xfs_dir2_shrink_inode(
693	xfs_da_args_t	*args,
694	xfs_dir2_db_t	db,
695	xfs_dabuf_t	*bp)
696{
697	xfs_fileoff_t	bno;		/* directory file offset */
698	xfs_dablk_t	da;		/* directory file offset */
699	int		done;		/* bunmap is finished */
700	xfs_inode_t	*dp;
701	int		error;
702	xfs_mount_t	*mp;
703	xfs_trans_t	*tp;
704
705	xfs_dir2_trace_args_db("shrink_inode", args, db, bp);
706	dp = args->dp;
707	mp = dp->i_mount;
708	tp = args->trans;
709	da = XFS_DIR2_DB_TO_DA(mp, db);
710	/*
711	 * Unmap the fsblock(s).
712	 */
713	if ((error = xfs_bunmapi(tp, dp, da, mp->m_dirblkfsbs,
714			XFS_BMAPI_METADATA, 0, args->firstblock, args->flist,
715			NULL, &done))) {
716		/*
717		 * ENOSPC actually can happen if we're in a removename with
718		 * no space reservation, and the resulting block removal
719		 * would cause a bmap btree split or conversion from extents
720		 * to btree.  This can only happen for un-fragmented
721		 * directory blocks, since you need to be punching out
722		 * the middle of an extent.
723		 * In this case we need to leave the block in the file,
724		 * and not binval it.
725		 * So the block has to be in a consistent empty state
726		 * and appropriately logged.
727		 * We don't free up the buffer, the caller can tell it
728		 * hasn't happened since it got an error back.
729		 */
730		return error;
731	}
732	ASSERT(done);
733	/*
734	 * Invalidate the buffer from the transaction.
735	 */
736	xfs_da_binval(tp, bp);
737	/*
738	 * If it's not a data block, we're done.
739	 */
740	if (db >= XFS_DIR2_LEAF_FIRSTDB(mp))
741		return 0;
742	/*
743	 * If the block isn't the last one in the directory, we're done.
744	 */
745	if (dp->i_d.di_size > XFS_DIR2_DB_OFF_TO_BYTE(mp, db + 1, 0))
746		return 0;
747	bno = da;
748	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
749		/*
750		 * This can't really happen unless there's kernel corruption.
751		 */
752		return error;
753	}
754	if (db == mp->m_dirdatablk)
755		ASSERT(bno == 0);
756	else
757		ASSERT(bno > 0);
758	/*
759	 * Set the size to the new last block.
760	 */
761	dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
762	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
763	return 0;
764}
765