xref: /linux/fs/xfs/xfs_itable.c (revision c98be0c96db00e9b6b02d31e0fa7590c54cdaaac)
1 /*
2  * Copyright (c) 2000-2002,2005 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_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_inum.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_mount.h"
28 #include "xfs_inode.h"
29 #include "xfs_btree.h"
30 #include "xfs_ialloc.h"
31 #include "xfs_ialloc_btree.h"
32 #include "xfs_itable.h"
33 #include "xfs_error.h"
34 #include "xfs_trace.h"
35 #include "xfs_icache.h"
36 #include "xfs_dinode.h"
37 
38 STATIC int
39 xfs_internal_inum(
40 	xfs_mount_t	*mp,
41 	xfs_ino_t	ino)
42 {
43 	return (ino == mp->m_sb.sb_rbmino || ino == mp->m_sb.sb_rsumino ||
44 		(xfs_sb_version_hasquota(&mp->m_sb) &&
45 		 xfs_is_quota_inode(&mp->m_sb, ino)));
46 }
47 
48 /*
49  * Return stat information for one inode.
50  * Return 0 if ok, else errno.
51  */
52 int
53 xfs_bulkstat_one_int(
54 	struct xfs_mount	*mp,		/* mount point for filesystem */
55 	xfs_ino_t		ino,		/* inode to get data for */
56 	void __user		*buffer,	/* buffer to place output in */
57 	int			ubsize,		/* size of buffer */
58 	bulkstat_one_fmt_pf	formatter,	/* formatter, copy to user */
59 	int			*ubused,	/* bytes used by me */
60 	int			*stat)		/* BULKSTAT_RV_... */
61 {
62 	struct xfs_icdinode	*dic;		/* dinode core info pointer */
63 	struct xfs_inode	*ip;		/* incore inode pointer */
64 	struct xfs_bstat	*buf;		/* return buffer */
65 	int			error = 0;	/* error value */
66 
67 	*stat = BULKSTAT_RV_NOTHING;
68 
69 	if (!buffer || xfs_internal_inum(mp, ino))
70 		return XFS_ERROR(EINVAL);
71 
72 	buf = kmem_alloc(sizeof(*buf), KM_SLEEP | KM_MAYFAIL);
73 	if (!buf)
74 		return XFS_ERROR(ENOMEM);
75 
76 	error = xfs_iget(mp, NULL, ino,
77 			 (XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
78 			 XFS_ILOCK_SHARED, &ip);
79 	if (error) {
80 		*stat = BULKSTAT_RV_NOTHING;
81 		goto out_free;
82 	}
83 
84 	ASSERT(ip != NULL);
85 	ASSERT(ip->i_imap.im_blkno != 0);
86 
87 	dic = &ip->i_d;
88 
89 	/* xfs_iget returns the following without needing
90 	 * further change.
91 	 */
92 	buf->bs_nlink = dic->di_nlink;
93 	buf->bs_projid_lo = dic->di_projid_lo;
94 	buf->bs_projid_hi = dic->di_projid_hi;
95 	buf->bs_ino = ino;
96 	buf->bs_mode = dic->di_mode;
97 	buf->bs_uid = dic->di_uid;
98 	buf->bs_gid = dic->di_gid;
99 	buf->bs_size = dic->di_size;
100 	buf->bs_atime.tv_sec = dic->di_atime.t_sec;
101 	buf->bs_atime.tv_nsec = dic->di_atime.t_nsec;
102 	buf->bs_mtime.tv_sec = dic->di_mtime.t_sec;
103 	buf->bs_mtime.tv_nsec = dic->di_mtime.t_nsec;
104 	buf->bs_ctime.tv_sec = dic->di_ctime.t_sec;
105 	buf->bs_ctime.tv_nsec = dic->di_ctime.t_nsec;
106 	buf->bs_xflags = xfs_ip2xflags(ip);
107 	buf->bs_extsize = dic->di_extsize << mp->m_sb.sb_blocklog;
108 	buf->bs_extents = dic->di_nextents;
109 	buf->bs_gen = dic->di_gen;
110 	memset(buf->bs_pad, 0, sizeof(buf->bs_pad));
111 	buf->bs_dmevmask = dic->di_dmevmask;
112 	buf->bs_dmstate = dic->di_dmstate;
113 	buf->bs_aextents = dic->di_anextents;
114 	buf->bs_forkoff = XFS_IFORK_BOFF(ip);
115 
116 	switch (dic->di_format) {
117 	case XFS_DINODE_FMT_DEV:
118 		buf->bs_rdev = ip->i_df.if_u2.if_rdev;
119 		buf->bs_blksize = BLKDEV_IOSIZE;
120 		buf->bs_blocks = 0;
121 		break;
122 	case XFS_DINODE_FMT_LOCAL:
123 	case XFS_DINODE_FMT_UUID:
124 		buf->bs_rdev = 0;
125 		buf->bs_blksize = mp->m_sb.sb_blocksize;
126 		buf->bs_blocks = 0;
127 		break;
128 	case XFS_DINODE_FMT_EXTENTS:
129 	case XFS_DINODE_FMT_BTREE:
130 		buf->bs_rdev = 0;
131 		buf->bs_blksize = mp->m_sb.sb_blocksize;
132 		buf->bs_blocks = dic->di_nblocks + ip->i_delayed_blks;
133 		break;
134 	}
135 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
136 	IRELE(ip);
137 
138 	error = formatter(buffer, ubsize, ubused, buf);
139 
140 	if (!error)
141 		*stat = BULKSTAT_RV_DIDONE;
142 
143  out_free:
144 	kmem_free(buf);
145 	return error;
146 }
147 
148 /* Return 0 on success or positive error */
149 STATIC int
150 xfs_bulkstat_one_fmt(
151 	void			__user *ubuffer,
152 	int			ubsize,
153 	int			*ubused,
154 	const xfs_bstat_t	*buffer)
155 {
156 	if (ubsize < sizeof(*buffer))
157 		return XFS_ERROR(ENOMEM);
158 	if (copy_to_user(ubuffer, buffer, sizeof(*buffer)))
159 		return XFS_ERROR(EFAULT);
160 	if (ubused)
161 		*ubused = sizeof(*buffer);
162 	return 0;
163 }
164 
165 int
166 xfs_bulkstat_one(
167 	xfs_mount_t	*mp,		/* mount point for filesystem */
168 	xfs_ino_t	ino,		/* inode number to get data for */
169 	void		__user *buffer,	/* buffer to place output in */
170 	int		ubsize,		/* size of buffer */
171 	int		*ubused,	/* bytes used by me */
172 	int		*stat)		/* BULKSTAT_RV_... */
173 {
174 	return xfs_bulkstat_one_int(mp, ino, buffer, ubsize,
175 				    xfs_bulkstat_one_fmt, ubused, stat);
176 }
177 
178 #define XFS_BULKSTAT_UBLEFT(ubleft)	((ubleft) >= statstruct_size)
179 
180 /*
181  * Return stat information in bulk (by-inode) for the filesystem.
182  */
183 int					/* error status */
184 xfs_bulkstat(
185 	xfs_mount_t		*mp,	/* mount point for filesystem */
186 	xfs_ino_t		*lastinop, /* last inode returned */
187 	int			*ubcountp, /* size of buffer/count returned */
188 	bulkstat_one_pf		formatter, /* func that'd fill a single buf */
189 	size_t			statstruct_size, /* sizeof struct filling */
190 	char			__user *ubuffer, /* buffer with inode stats */
191 	int			*done)	/* 1 if there are more stats to get */
192 {
193 	xfs_agblock_t		agbno=0;/* allocation group block number */
194 	xfs_buf_t		*agbp;	/* agi header buffer */
195 	xfs_agi_t		*agi;	/* agi header data */
196 	xfs_agino_t		agino;	/* inode # in allocation group */
197 	xfs_agnumber_t		agno;	/* allocation group number */
198 	int			chunkidx; /* current index into inode chunk */
199 	int			clustidx; /* current index into inode cluster */
200 	xfs_btree_cur_t		*cur;	/* btree cursor for ialloc btree */
201 	int			end_of_ag; /* set if we've seen the ag end */
202 	int			error;	/* error code */
203 	int                     fmterror;/* bulkstat formatter result */
204 	int			i;	/* loop index */
205 	int			icount;	/* count of inodes good in irbuf */
206 	size_t			irbsize; /* size of irec buffer in bytes */
207 	xfs_ino_t		ino;	/* inode number (filesystem) */
208 	xfs_inobt_rec_incore_t	*irbp;	/* current irec buffer pointer */
209 	xfs_inobt_rec_incore_t	*irbuf;	/* start of irec buffer */
210 	xfs_inobt_rec_incore_t	*irbufend; /* end of good irec buffer entries */
211 	xfs_ino_t		lastino; /* last inode number returned */
212 	int			blks_per_cluster; /* # of blocks per cluster */
213 	int			inodes_per_cluster;/* # of inodes per cluster */
214 	int			nirbuf;	/* size of irbuf */
215 	int			rval;	/* return value error code */
216 	int			tmp;	/* result value from btree calls */
217 	int			ubcount; /* size of user's buffer */
218 	int			ubleft;	/* bytes left in user's buffer */
219 	char			__user *ubufp;	/* pointer into user's buffer */
220 	int			ubelem;	/* spaces used in user's buffer */
221 	int			ubused;	/* bytes used by formatter */
222 
223 	/*
224 	 * Get the last inode value, see if there's nothing to do.
225 	 */
226 	ino = (xfs_ino_t)*lastinop;
227 	lastino = ino;
228 	agno = XFS_INO_TO_AGNO(mp, ino);
229 	agino = XFS_INO_TO_AGINO(mp, ino);
230 	if (agno >= mp->m_sb.sb_agcount ||
231 	    ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
232 		*done = 1;
233 		*ubcountp = 0;
234 		return 0;
235 	}
236 	if (!ubcountp || *ubcountp <= 0) {
237 		return EINVAL;
238 	}
239 	ubcount = *ubcountp; /* statstruct's */
240 	ubleft = ubcount * statstruct_size; /* bytes */
241 	*ubcountp = ubelem = 0;
242 	*done = 0;
243 	fmterror = 0;
244 	ubufp = ubuffer;
245 	blks_per_cluster = xfs_icluster_size_fsb(mp);
246 	inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
247 	irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4);
248 	if (!irbuf)
249 		return ENOMEM;
250 
251 	nirbuf = irbsize / sizeof(*irbuf);
252 
253 	/*
254 	 * Loop over the allocation groups, starting from the last
255 	 * inode returned; 0 means start of the allocation group.
256 	 */
257 	rval = 0;
258 	while (XFS_BULKSTAT_UBLEFT(ubleft) && agno < mp->m_sb.sb_agcount) {
259 		cond_resched();
260 		error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
261 		if (error) {
262 			/*
263 			 * Skip this allocation group and go to the next one.
264 			 */
265 			agno++;
266 			agino = 0;
267 			continue;
268 		}
269 		agi = XFS_BUF_TO_AGI(agbp);
270 		/*
271 		 * Allocate and initialize a btree cursor for ialloc btree.
272 		 */
273 		cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno);
274 		irbp = irbuf;
275 		irbufend = irbuf + nirbuf;
276 		end_of_ag = 0;
277 		/*
278 		 * If we're returning in the middle of an allocation group,
279 		 * we need to get the remainder of the chunk we're in.
280 		 */
281 		if (agino > 0) {
282 			xfs_inobt_rec_incore_t r;
283 
284 			/*
285 			 * Lookup the inode chunk that this inode lives in.
286 			 */
287 			error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE,
288 						 &tmp);
289 			if (!error &&	/* no I/O error */
290 			    tmp &&	/* lookup succeeded */
291 					/* got the record, should always work */
292 			    !(error = xfs_inobt_get_rec(cur, &r, &i)) &&
293 			    i == 1 &&
294 					/* this is the right chunk */
295 			    agino < r.ir_startino + XFS_INODES_PER_CHUNK &&
296 					/* lastino was not last in chunk */
297 			    (chunkidx = agino - r.ir_startino + 1) <
298 				    XFS_INODES_PER_CHUNK &&
299 					/* there are some left allocated */
300 			    xfs_inobt_maskn(chunkidx,
301 				    XFS_INODES_PER_CHUNK - chunkidx) &
302 				    ~r.ir_free) {
303 				/*
304 				 * Grab the chunk record.  Mark all the
305 				 * uninteresting inodes (because they're
306 				 * before our start point) free.
307 				 */
308 				for (i = 0; i < chunkidx; i++) {
309 					if (XFS_INOBT_MASK(i) & ~r.ir_free)
310 						r.ir_freecount++;
311 				}
312 				r.ir_free |= xfs_inobt_maskn(0, chunkidx);
313 				irbp->ir_startino = r.ir_startino;
314 				irbp->ir_freecount = r.ir_freecount;
315 				irbp->ir_free = r.ir_free;
316 				irbp++;
317 				agino = r.ir_startino + XFS_INODES_PER_CHUNK;
318 				icount = XFS_INODES_PER_CHUNK - r.ir_freecount;
319 			} else {
320 				/*
321 				 * If any of those tests failed, bump the
322 				 * inode number (just in case).
323 				 */
324 				agino++;
325 				icount = 0;
326 			}
327 			/*
328 			 * In any case, increment to the next record.
329 			 */
330 			if (!error)
331 				error = xfs_btree_increment(cur, 0, &tmp);
332 		} else {
333 			/*
334 			 * Start of ag.  Lookup the first inode chunk.
335 			 */
336 			error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &tmp);
337 			icount = 0;
338 		}
339 		/*
340 		 * Loop through inode btree records in this ag,
341 		 * until we run out of inodes or space in the buffer.
342 		 */
343 		while (irbp < irbufend && icount < ubcount) {
344 			xfs_inobt_rec_incore_t r;
345 
346 			/*
347 			 * Loop as long as we're unable to read the
348 			 * inode btree.
349 			 */
350 			while (error) {
351 				agino += XFS_INODES_PER_CHUNK;
352 				if (XFS_AGINO_TO_AGBNO(mp, agino) >=
353 						be32_to_cpu(agi->agi_length))
354 					break;
355 				error = xfs_inobt_lookup(cur, agino,
356 							 XFS_LOOKUP_GE, &tmp);
357 				cond_resched();
358 			}
359 			/*
360 			 * If ran off the end of the ag either with an error,
361 			 * or the normal way, set end and stop collecting.
362 			 */
363 			if (error) {
364 				end_of_ag = 1;
365 				break;
366 			}
367 
368 			error = xfs_inobt_get_rec(cur, &r, &i);
369 			if (error || i == 0) {
370 				end_of_ag = 1;
371 				break;
372 			}
373 
374 			/*
375 			 * If this chunk has any allocated inodes, save it.
376 			 * Also start read-ahead now for this chunk.
377 			 */
378 			if (r.ir_freecount < XFS_INODES_PER_CHUNK) {
379 				struct blk_plug	plug;
380 				/*
381 				 * Loop over all clusters in the next chunk.
382 				 * Do a readahead if there are any allocated
383 				 * inodes in that cluster.
384 				 */
385 				blk_start_plug(&plug);
386 				agbno = XFS_AGINO_TO_AGBNO(mp, r.ir_startino);
387 				for (chunkidx = 0;
388 				     chunkidx < XFS_INODES_PER_CHUNK;
389 				     chunkidx += inodes_per_cluster,
390 				     agbno += blks_per_cluster) {
391 					if (xfs_inobt_maskn(chunkidx,
392 					    inodes_per_cluster) & ~r.ir_free)
393 						xfs_btree_reada_bufs(mp, agno,
394 							agbno, blks_per_cluster,
395 							&xfs_inode_buf_ops);
396 				}
397 				blk_finish_plug(&plug);
398 				irbp->ir_startino = r.ir_startino;
399 				irbp->ir_freecount = r.ir_freecount;
400 				irbp->ir_free = r.ir_free;
401 				irbp++;
402 				icount += XFS_INODES_PER_CHUNK - r.ir_freecount;
403 			}
404 			/*
405 			 * Set agino to after this chunk and bump the cursor.
406 			 */
407 			agino = r.ir_startino + XFS_INODES_PER_CHUNK;
408 			error = xfs_btree_increment(cur, 0, &tmp);
409 			cond_resched();
410 		}
411 		/*
412 		 * Drop the btree buffers and the agi buffer.
413 		 * We can't hold any of the locks these represent
414 		 * when calling iget.
415 		 */
416 		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
417 		xfs_buf_relse(agbp);
418 		/*
419 		 * Now format all the good inodes into the user's buffer.
420 		 */
421 		irbufend = irbp;
422 		for (irbp = irbuf;
423 		     irbp < irbufend && XFS_BULKSTAT_UBLEFT(ubleft); irbp++) {
424 			/*
425 			 * Now process this chunk of inodes.
426 			 */
427 			for (agino = irbp->ir_startino, chunkidx = clustidx = 0;
428 			     XFS_BULKSTAT_UBLEFT(ubleft) &&
429 				irbp->ir_freecount < XFS_INODES_PER_CHUNK;
430 			     chunkidx++, clustidx++, agino++) {
431 				ASSERT(chunkidx < XFS_INODES_PER_CHUNK);
432 
433 				ino = XFS_AGINO_TO_INO(mp, agno, agino);
434 				/*
435 				 * Skip if this inode is free.
436 				 */
437 				if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free) {
438 					lastino = ino;
439 					continue;
440 				}
441 				/*
442 				 * Count used inodes as free so we can tell
443 				 * when the chunk is used up.
444 				 */
445 				irbp->ir_freecount++;
446 
447 				/*
448 				 * Get the inode and fill in a single buffer.
449 				 */
450 				ubused = statstruct_size;
451 				error = formatter(mp, ino, ubufp, ubleft,
452 						  &ubused, &fmterror);
453 				if (fmterror == BULKSTAT_RV_NOTHING) {
454 					if (error && error != ENOENT &&
455 						error != EINVAL) {
456 						ubleft = 0;
457 						rval = error;
458 						break;
459 					}
460 					lastino = ino;
461 					continue;
462 				}
463 				if (fmterror == BULKSTAT_RV_GIVEUP) {
464 					ubleft = 0;
465 					ASSERT(error);
466 					rval = error;
467 					break;
468 				}
469 				if (ubufp)
470 					ubufp += ubused;
471 				ubleft -= ubused;
472 				ubelem++;
473 				lastino = ino;
474 			}
475 
476 			cond_resched();
477 		}
478 		/*
479 		 * Set up for the next loop iteration.
480 		 */
481 		if (XFS_BULKSTAT_UBLEFT(ubleft)) {
482 			if (end_of_ag) {
483 				agno++;
484 				agino = 0;
485 			} else
486 				agino = XFS_INO_TO_AGINO(mp, lastino);
487 		} else
488 			break;
489 	}
490 	/*
491 	 * Done, we're either out of filesystem or space to put the data.
492 	 */
493 	kmem_free(irbuf);
494 	*ubcountp = ubelem;
495 	/*
496 	 * Found some inodes, return them now and return the error next time.
497 	 */
498 	if (ubelem)
499 		rval = 0;
500 	if (agno >= mp->m_sb.sb_agcount) {
501 		/*
502 		 * If we ran out of filesystem, mark lastino as off
503 		 * the end of the filesystem, so the next call
504 		 * will return immediately.
505 		 */
506 		*lastinop = (xfs_ino_t)XFS_AGINO_TO_INO(mp, agno, 0);
507 		*done = 1;
508 	} else
509 		*lastinop = (xfs_ino_t)lastino;
510 
511 	return rval;
512 }
513 
514 /*
515  * Return stat information in bulk (by-inode) for the filesystem.
516  * Special case for non-sequential one inode bulkstat.
517  */
518 int					/* error status */
519 xfs_bulkstat_single(
520 	xfs_mount_t		*mp,	/* mount point for filesystem */
521 	xfs_ino_t		*lastinop, /* inode to return */
522 	char			__user *buffer, /* buffer with inode stats */
523 	int			*done)	/* 1 if there are more stats to get */
524 {
525 	int			count;	/* count value for bulkstat call */
526 	int			error;	/* return value */
527 	xfs_ino_t		ino;	/* filesystem inode number */
528 	int			res;	/* result from bs1 */
529 
530 	/*
531 	 * note that requesting valid inode numbers which are not allocated
532 	 * to inodes will most likely cause xfs_imap_to_bp to generate warning
533 	 * messages about bad magic numbers. This is ok. The fact that
534 	 * the inode isn't actually an inode is handled by the
535 	 * error check below. Done this way to make the usual case faster
536 	 * at the expense of the error case.
537 	 */
538 
539 	ino = *lastinop;
540 	error = xfs_bulkstat_one(mp, ino, buffer, sizeof(xfs_bstat_t),
541 				 NULL, &res);
542 	if (error) {
543 		/*
544 		 * Special case way failed, do it the "long" way
545 		 * to see if that works.
546 		 */
547 		(*lastinop)--;
548 		count = 1;
549 		if (xfs_bulkstat(mp, lastinop, &count, xfs_bulkstat_one,
550 				sizeof(xfs_bstat_t), buffer, done))
551 			return error;
552 		if (count == 0 || (xfs_ino_t)*lastinop != ino)
553 			return error == EFSCORRUPTED ?
554 				XFS_ERROR(EINVAL) : error;
555 		else
556 			return 0;
557 	}
558 	*done = 0;
559 	return 0;
560 }
561 
562 int
563 xfs_inumbers_fmt(
564 	void			__user *ubuffer, /* buffer to write to */
565 	const xfs_inogrp_t	*buffer,	/* buffer to read from */
566 	long			count,		/* # of elements to read */
567 	long			*written)	/* # of bytes written */
568 {
569 	if (copy_to_user(ubuffer, buffer, count * sizeof(*buffer)))
570 		return -EFAULT;
571 	*written = count * sizeof(*buffer);
572 	return 0;
573 }
574 
575 /*
576  * Return inode number table for the filesystem.
577  */
578 int					/* error status */
579 xfs_inumbers(
580 	xfs_mount_t	*mp,		/* mount point for filesystem */
581 	xfs_ino_t	*lastino,	/* last inode returned */
582 	int		*count,		/* size of buffer/count returned */
583 	void		__user *ubuffer,/* buffer with inode descriptions */
584 	inumbers_fmt_pf	formatter)
585 {
586 	xfs_buf_t	*agbp;
587 	xfs_agino_t	agino;
588 	xfs_agnumber_t	agno;
589 	int		bcount;
590 	xfs_inogrp_t	*buffer;
591 	int		bufidx;
592 	xfs_btree_cur_t	*cur;
593 	int		error;
594 	xfs_inobt_rec_incore_t r;
595 	int		i;
596 	xfs_ino_t	ino;
597 	int		left;
598 	int		tmp;
599 
600 	ino = (xfs_ino_t)*lastino;
601 	agno = XFS_INO_TO_AGNO(mp, ino);
602 	agino = XFS_INO_TO_AGINO(mp, ino);
603 	left = *count;
604 	*count = 0;
605 	bcount = MIN(left, (int)(PAGE_SIZE / sizeof(*buffer)));
606 	buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP);
607 	error = bufidx = 0;
608 	cur = NULL;
609 	agbp = NULL;
610 	while (left > 0 && agno < mp->m_sb.sb_agcount) {
611 		if (agbp == NULL) {
612 			error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
613 			if (error) {
614 				/*
615 				 * If we can't read the AGI of this ag,
616 				 * then just skip to the next one.
617 				 */
618 				ASSERT(cur == NULL);
619 				agbp = NULL;
620 				agno++;
621 				agino = 0;
622 				continue;
623 			}
624 			cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno);
625 			error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_GE,
626 						 &tmp);
627 			if (error) {
628 				xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
629 				cur = NULL;
630 				xfs_buf_relse(agbp);
631 				agbp = NULL;
632 				/*
633 				 * Move up the last inode in the current
634 				 * chunk.  The lookup_ge will always get
635 				 * us the first inode in the next chunk.
636 				 */
637 				agino += XFS_INODES_PER_CHUNK - 1;
638 				continue;
639 			}
640 		}
641 		error = xfs_inobt_get_rec(cur, &r, &i);
642 		if (error || i == 0) {
643 			xfs_buf_relse(agbp);
644 			agbp = NULL;
645 			xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
646 			cur = NULL;
647 			agno++;
648 			agino = 0;
649 			continue;
650 		}
651 		agino = r.ir_startino + XFS_INODES_PER_CHUNK - 1;
652 		buffer[bufidx].xi_startino =
653 			XFS_AGINO_TO_INO(mp, agno, r.ir_startino);
654 		buffer[bufidx].xi_alloccount =
655 			XFS_INODES_PER_CHUNK - r.ir_freecount;
656 		buffer[bufidx].xi_allocmask = ~r.ir_free;
657 		bufidx++;
658 		left--;
659 		if (bufidx == bcount) {
660 			long written;
661 			if (formatter(ubuffer, buffer, bufidx, &written)) {
662 				error = XFS_ERROR(EFAULT);
663 				break;
664 			}
665 			ubuffer += written;
666 			*count += bufidx;
667 			bufidx = 0;
668 		}
669 		if (left) {
670 			error = xfs_btree_increment(cur, 0, &tmp);
671 			if (error) {
672 				xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
673 				cur = NULL;
674 				xfs_buf_relse(agbp);
675 				agbp = NULL;
676 				/*
677 				 * The agino value has already been bumped.
678 				 * Just try to skip up to it.
679 				 */
680 				agino += XFS_INODES_PER_CHUNK;
681 				continue;
682 			}
683 		}
684 	}
685 	if (!error) {
686 		if (bufidx) {
687 			long written;
688 			if (formatter(ubuffer, buffer, bufidx, &written))
689 				error = XFS_ERROR(EFAULT);
690 			else
691 				*count += bufidx;
692 		}
693 		*lastino = XFS_AGINO_TO_INO(mp, agno, agino);
694 	}
695 	kmem_free(buffer);
696 	if (cur)
697 		xfs_btree_del_cursor(cur, (error ? XFS_BTREE_ERROR :
698 					   XFS_BTREE_NOERROR));
699 	if (agbp)
700 		xfs_buf_relse(agbp);
701 	return error;
702 }
703