xref: /openbmc/linux/fs/xfs/xfs_fsops.c (revision 1da177e4)
1 /*
2  * Copyright (c) 2000-2002 Silicon Graphics, Inc.  All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it is
13  * free of the rightful claim of any third person regarding infringement
14  * or the like.  Any license provided herein, whether implied or
15  * otherwise, applies only to this software file.  Patent licenses, if
16  * any, provided herein do not apply to combinations of this program with
17  * other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write the Free Software Foundation, Inc., 59
21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22  *
23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24  * Mountain View, CA  94043, or:
25  *
26  * http://www.sgi.com
27  *
28  * For further information regarding this notice, see:
29  *
30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31  */
32 
33 #include "xfs.h"
34 #include "xfs_macros.h"
35 #include "xfs_types.h"
36 #include "xfs_inum.h"
37 #include "xfs_log.h"
38 #include "xfs_trans.h"
39 #include "xfs_sb.h"
40 #include "xfs_dir.h"
41 #include "xfs_dmapi.h"
42 #include "xfs_mount.h"
43 #include "xfs_ag.h"
44 #include "xfs_alloc_btree.h"
45 #include "xfs_bmap_btree.h"
46 #include "xfs_ialloc_btree.h"
47 #include "xfs_btree.h"
48 #include "xfs_error.h"
49 #include "xfs_alloc.h"
50 #include "xfs_ialloc.h"
51 #include "xfs_fsops.h"
52 #include "xfs_itable.h"
53 #include "xfs_rw.h"
54 #include "xfs_refcache.h"
55 #include "xfs_trans_space.h"
56 #include "xfs_rtalloc.h"
57 #include "xfs_dir2.h"
58 #include "xfs_attr_sf.h"
59 #include "xfs_dir_sf.h"
60 #include "xfs_dir2_sf.h"
61 #include "xfs_dinode.h"
62 #include "xfs_inode.h"
63 #include "xfs_inode_item.h"
64 
65 /*
66  * File system operations
67  */
68 
69 int
70 xfs_fs_geometry(
71 	xfs_mount_t		*mp,
72 	xfs_fsop_geom_t		*geo,
73 	int			new_version)
74 {
75 	geo->blocksize = mp->m_sb.sb_blocksize;
76 	geo->rtextsize = mp->m_sb.sb_rextsize;
77 	geo->agblocks = mp->m_sb.sb_agblocks;
78 	geo->agcount = mp->m_sb.sb_agcount;
79 	geo->logblocks = mp->m_sb.sb_logblocks;
80 	geo->sectsize = mp->m_sb.sb_sectsize;
81 	geo->inodesize = mp->m_sb.sb_inodesize;
82 	geo->imaxpct = mp->m_sb.sb_imax_pct;
83 	geo->datablocks = mp->m_sb.sb_dblocks;
84 	geo->rtblocks = mp->m_sb.sb_rblocks;
85 	geo->rtextents = mp->m_sb.sb_rextents;
86 	geo->logstart = mp->m_sb.sb_logstart;
87 	ASSERT(sizeof(geo->uuid)==sizeof(mp->m_sb.sb_uuid));
88 	memcpy(geo->uuid, &mp->m_sb.sb_uuid, sizeof(mp->m_sb.sb_uuid));
89 	if (new_version >= 2) {
90 		geo->sunit = mp->m_sb.sb_unit;
91 		geo->swidth = mp->m_sb.sb_width;
92 	}
93 	if (new_version >= 3) {
94 		geo->version = XFS_FSOP_GEOM_VERSION;
95 		geo->flags =
96 			(XFS_SB_VERSION_HASATTR(&mp->m_sb) ?
97 				XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
98 			(XFS_SB_VERSION_HASNLINK(&mp->m_sb) ?
99 				XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
100 			(XFS_SB_VERSION_HASQUOTA(&mp->m_sb) ?
101 				XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
102 			(XFS_SB_VERSION_HASALIGN(&mp->m_sb) ?
103 				XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
104 			(XFS_SB_VERSION_HASDALIGN(&mp->m_sb) ?
105 				XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
106 			(XFS_SB_VERSION_HASSHARED(&mp->m_sb) ?
107 				XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
108 			(XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb) ?
109 				XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
110 			(XFS_SB_VERSION_HASDIRV2(&mp->m_sb) ?
111 				XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
112 			(XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
113 				XFS_FSOP_GEOM_FLAGS_SECTOR : 0);
114 		geo->logsectsize = XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
115 				mp->m_sb.sb_logsectsize : BBSIZE;
116 		geo->rtsectsize = mp->m_sb.sb_blocksize;
117 		geo->dirblocksize = mp->m_dirblksize;
118 	}
119 	if (new_version >= 4) {
120 		geo->flags |=
121 			(XFS_SB_VERSION_HASLOGV2(&mp->m_sb) ?
122 				XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
123 		geo->logsunit = mp->m_sb.sb_logsunit;
124 	}
125 	return 0;
126 }
127 
128 static int
129 xfs_growfs_data_private(
130 	xfs_mount_t		*mp,		/* mount point for filesystem */
131 	xfs_growfs_data_t	*in)		/* growfs data input struct */
132 {
133 	xfs_agf_t		*agf;
134 	xfs_agi_t		*agi;
135 	xfs_agnumber_t		agno;
136 	xfs_extlen_t		agsize;
137 	xfs_extlen_t		tmpsize;
138 	xfs_alloc_rec_t		*arec;
139 	xfs_btree_sblock_t	*block;
140 	xfs_buf_t		*bp;
141 	int			bucket;
142 	int			dpct;
143 	int			error;
144 	xfs_agnumber_t		nagcount;
145 	xfs_agnumber_t		nagimax = 0;
146 	xfs_rfsblock_t		nb, nb_mod;
147 	xfs_rfsblock_t		new;
148 	xfs_rfsblock_t		nfree;
149 	xfs_agnumber_t		oagcount;
150 	int			pct;
151 	xfs_sb_t		*sbp;
152 	xfs_trans_t		*tp;
153 
154 	nb = in->newblocks;
155 	pct = in->imaxpct;
156 	if (nb < mp->m_sb.sb_dblocks || pct < 0 || pct > 100)
157 		return XFS_ERROR(EINVAL);
158 	dpct = pct - mp->m_sb.sb_imax_pct;
159 	error = xfs_read_buf(mp, mp->m_ddev_targp,
160 			XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
161 			XFS_FSS_TO_BB(mp, 1), 0, &bp);
162 	if (error)
163 		return error;
164 	ASSERT(bp);
165 	xfs_buf_relse(bp);
166 
167 	new = nb;	/* use new as a temporary here */
168 	nb_mod = do_div(new, mp->m_sb.sb_agblocks);
169 	nagcount = new + (nb_mod != 0);
170 	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
171 		nagcount--;
172 		nb = nagcount * mp->m_sb.sb_agblocks;
173 		if (nb < mp->m_sb.sb_dblocks)
174 			return XFS_ERROR(EINVAL);
175 	}
176 	new = nb - mp->m_sb.sb_dblocks;
177 	oagcount = mp->m_sb.sb_agcount;
178 	if (nagcount > oagcount) {
179 		down_write(&mp->m_peraglock);
180 		mp->m_perag = kmem_realloc(mp->m_perag,
181 			sizeof(xfs_perag_t) * nagcount,
182 			sizeof(xfs_perag_t) * oagcount,
183 			KM_SLEEP);
184 		memset(&mp->m_perag[oagcount], 0,
185 			(nagcount - oagcount) * sizeof(xfs_perag_t));
186 		mp->m_flags |= XFS_MOUNT_32BITINODES;
187 		nagimax = xfs_initialize_perag(mp, nagcount);
188 		up_write(&mp->m_peraglock);
189 	}
190 	tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
191 	if ((error = xfs_trans_reserve(tp, XFS_GROWFS_SPACE_RES(mp),
192 			XFS_GROWDATA_LOG_RES(mp), 0, 0, 0))) {
193 		xfs_trans_cancel(tp, 0);
194 		return error;
195 	}
196 
197 	nfree = 0;
198 	for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
199 		/*
200 		 * AG freelist header block
201 		 */
202 		bp = xfs_buf_get(mp->m_ddev_targp,
203 				  XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
204 				  XFS_FSS_TO_BB(mp, 1), 0);
205 		agf = XFS_BUF_TO_AGF(bp);
206 		memset(agf, 0, mp->m_sb.sb_sectsize);
207 		INT_SET(agf->agf_magicnum, ARCH_CONVERT, XFS_AGF_MAGIC);
208 		INT_SET(agf->agf_versionnum, ARCH_CONVERT, XFS_AGF_VERSION);
209 		INT_SET(agf->agf_seqno, ARCH_CONVERT, agno);
210 		if (agno == nagcount - 1)
211 			agsize =
212 				nb -
213 				(agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
214 		else
215 			agsize = mp->m_sb.sb_agblocks;
216 		INT_SET(agf->agf_length, ARCH_CONVERT, agsize);
217 		INT_SET(agf->agf_roots[XFS_BTNUM_BNOi], ARCH_CONVERT,
218 			XFS_BNO_BLOCK(mp));
219 		INT_SET(agf->agf_roots[XFS_BTNUM_CNTi], ARCH_CONVERT,
220 			XFS_CNT_BLOCK(mp));
221 		INT_SET(agf->agf_levels[XFS_BTNUM_BNOi], ARCH_CONVERT, 1);
222 		INT_SET(agf->agf_levels[XFS_BTNUM_CNTi], ARCH_CONVERT, 1);
223 		agf->agf_flfirst = 0;
224 		INT_SET(agf->agf_fllast, ARCH_CONVERT, XFS_AGFL_SIZE(mp) - 1);
225 		agf->agf_flcount = 0;
226 		tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
227 		INT_SET(agf->agf_freeblks, ARCH_CONVERT, tmpsize);
228 		INT_SET(agf->agf_longest, ARCH_CONVERT, tmpsize);
229 		error = xfs_bwrite(mp, bp);
230 		if (error) {
231 			goto error0;
232 		}
233 		/*
234 		 * AG inode header block
235 		 */
236 		bp = xfs_buf_get(mp->m_ddev_targp,
237 				  XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
238 				  XFS_FSS_TO_BB(mp, 1), 0);
239 		agi = XFS_BUF_TO_AGI(bp);
240 		memset(agi, 0, mp->m_sb.sb_sectsize);
241 		INT_SET(agi->agi_magicnum, ARCH_CONVERT, XFS_AGI_MAGIC);
242 		INT_SET(agi->agi_versionnum, ARCH_CONVERT, XFS_AGI_VERSION);
243 		INT_SET(agi->agi_seqno, ARCH_CONVERT, agno);
244 		INT_SET(agi->agi_length, ARCH_CONVERT, agsize);
245 		agi->agi_count = 0;
246 		INT_SET(agi->agi_root, ARCH_CONVERT, XFS_IBT_BLOCK(mp));
247 		INT_SET(agi->agi_level, ARCH_CONVERT, 1);
248 		agi->agi_freecount = 0;
249 		INT_SET(agi->agi_newino, ARCH_CONVERT, NULLAGINO);
250 		INT_SET(agi->agi_dirino, ARCH_CONVERT, NULLAGINO);
251 		for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
252 			INT_SET(agi->agi_unlinked[bucket], ARCH_CONVERT,
253 				NULLAGINO);
254 		error = xfs_bwrite(mp, bp);
255 		if (error) {
256 			goto error0;
257 		}
258 		/*
259 		 * BNO btree root block
260 		 */
261 		bp = xfs_buf_get(mp->m_ddev_targp,
262 			XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
263 			BTOBB(mp->m_sb.sb_blocksize), 0);
264 		block = XFS_BUF_TO_SBLOCK(bp);
265 		memset(block, 0, mp->m_sb.sb_blocksize);
266 		INT_SET(block->bb_magic, ARCH_CONVERT, XFS_ABTB_MAGIC);
267 		block->bb_level = 0;
268 		INT_SET(block->bb_numrecs, ARCH_CONVERT, 1);
269 		INT_SET(block->bb_leftsib, ARCH_CONVERT, NULLAGBLOCK);
270 		INT_SET(block->bb_rightsib, ARCH_CONVERT, NULLAGBLOCK);
271 		arec = XFS_BTREE_REC_ADDR(mp->m_sb.sb_blocksize, xfs_alloc,
272 			block, 1, mp->m_alloc_mxr[0]);
273 		INT_SET(arec->ar_startblock, ARCH_CONVERT,
274 			XFS_PREALLOC_BLOCKS(mp));
275 		INT_SET(arec->ar_blockcount, ARCH_CONVERT,
276 			agsize - INT_GET(arec->ar_startblock, ARCH_CONVERT));
277 		error = xfs_bwrite(mp, bp);
278 		if (error) {
279 			goto error0;
280 		}
281 		/*
282 		 * CNT btree root block
283 		 */
284 		bp = xfs_buf_get(mp->m_ddev_targp,
285 			XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
286 			BTOBB(mp->m_sb.sb_blocksize), 0);
287 		block = XFS_BUF_TO_SBLOCK(bp);
288 		memset(block, 0, mp->m_sb.sb_blocksize);
289 		INT_SET(block->bb_magic, ARCH_CONVERT, XFS_ABTC_MAGIC);
290 		block->bb_level = 0;
291 		INT_SET(block->bb_numrecs, ARCH_CONVERT, 1);
292 		INT_SET(block->bb_leftsib, ARCH_CONVERT, NULLAGBLOCK);
293 		INT_SET(block->bb_rightsib, ARCH_CONVERT, NULLAGBLOCK);
294 		arec = XFS_BTREE_REC_ADDR(mp->m_sb.sb_blocksize, xfs_alloc,
295 			block, 1, mp->m_alloc_mxr[0]);
296 		INT_SET(arec->ar_startblock, ARCH_CONVERT,
297 			XFS_PREALLOC_BLOCKS(mp));
298 		INT_SET(arec->ar_blockcount, ARCH_CONVERT,
299 			agsize - INT_GET(arec->ar_startblock, ARCH_CONVERT));
300 		nfree += INT_GET(arec->ar_blockcount, ARCH_CONVERT);
301 		error = xfs_bwrite(mp, bp);
302 		if (error) {
303 			goto error0;
304 		}
305 		/*
306 		 * INO btree root block
307 		 */
308 		bp = xfs_buf_get(mp->m_ddev_targp,
309 			XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
310 			BTOBB(mp->m_sb.sb_blocksize), 0);
311 		block = XFS_BUF_TO_SBLOCK(bp);
312 		memset(block, 0, mp->m_sb.sb_blocksize);
313 		INT_SET(block->bb_magic, ARCH_CONVERT, XFS_IBT_MAGIC);
314 		block->bb_level = 0;
315 		block->bb_numrecs = 0;
316 		INT_SET(block->bb_leftsib, ARCH_CONVERT, NULLAGBLOCK);
317 		INT_SET(block->bb_rightsib, ARCH_CONVERT, NULLAGBLOCK);
318 		error = xfs_bwrite(mp, bp);
319 		if (error) {
320 			goto error0;
321 		}
322 	}
323 	xfs_trans_agblocks_delta(tp, nfree);
324 	/*
325 	 * There are new blocks in the old last a.g.
326 	 */
327 	if (new) {
328 		/*
329 		 * Change the agi length.
330 		 */
331 		error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
332 		if (error) {
333 			goto error0;
334 		}
335 		ASSERT(bp);
336 		agi = XFS_BUF_TO_AGI(bp);
337 		INT_MOD(agi->agi_length, ARCH_CONVERT, new);
338 		ASSERT(nagcount == oagcount ||
339 		       INT_GET(agi->agi_length, ARCH_CONVERT) ==
340 				mp->m_sb.sb_agblocks);
341 		xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
342 		/*
343 		 * Change agf length.
344 		 */
345 		error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
346 		if (error) {
347 			goto error0;
348 		}
349 		ASSERT(bp);
350 		agf = XFS_BUF_TO_AGF(bp);
351 		INT_MOD(agf->agf_length, ARCH_CONVERT, new);
352 		ASSERT(INT_GET(agf->agf_length, ARCH_CONVERT) ==
353 				INT_GET(agi->agi_length, ARCH_CONVERT));
354 		/*
355 		 * Free the new space.
356 		 */
357 		error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
358 			INT_GET(agf->agf_length, ARCH_CONVERT) - new), new);
359 		if (error) {
360 			goto error0;
361 		}
362 	}
363 	if (nagcount > oagcount)
364 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
365 	if (nb > mp->m_sb.sb_dblocks)
366 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
367 				 nb - mp->m_sb.sb_dblocks);
368 	if (nfree)
369 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
370 	if (dpct)
371 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
372 	error = xfs_trans_commit(tp, 0, NULL);
373 	if (error) {
374 		return error;
375 	}
376 	/* New allocation groups fully initialized, so update mount struct */
377 	if (nagimax)
378 		mp->m_maxagi = nagimax;
379 	if (mp->m_sb.sb_imax_pct) {
380 		__uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
381 		do_div(icount, 100);
382 		mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
383 	} else
384 		mp->m_maxicount = 0;
385 	for (agno = 1; agno < nagcount; agno++) {
386 		error = xfs_read_buf(mp, mp->m_ddev_targp,
387 				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
388 				  XFS_FSS_TO_BB(mp, 1), 0, &bp);
389 		if (error) {
390 			xfs_fs_cmn_err(CE_WARN, mp,
391 			"error %d reading secondary superblock for ag %d",
392 				error, agno);
393 			break;
394 		}
395 		sbp = XFS_BUF_TO_SBP(bp);
396 		xfs_xlatesb(sbp, &mp->m_sb, -1, XFS_SB_ALL_BITS);
397 		/*
398 		 * If we get an error writing out the alternate superblocks,
399 		 * just issue a warning and continue.  The real work is
400 		 * already done and committed.
401 		 */
402 		if (!(error = xfs_bwrite(mp, bp))) {
403 			continue;
404 		} else {
405 			xfs_fs_cmn_err(CE_WARN, mp,
406 		"write error %d updating secondary superblock for ag %d",
407 				error, agno);
408 			break; /* no point in continuing */
409 		}
410 	}
411 	return 0;
412 
413  error0:
414 	xfs_trans_cancel(tp, XFS_TRANS_ABORT);
415 	return error;
416 }
417 
418 static int
419 xfs_growfs_log_private(
420 	xfs_mount_t		*mp,	/* mount point for filesystem */
421 	xfs_growfs_log_t	*in)	/* growfs log input struct */
422 {
423 	xfs_extlen_t		nb;
424 
425 	nb = in->newblocks;
426 	if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
427 		return XFS_ERROR(EINVAL);
428 	if (nb == mp->m_sb.sb_logblocks &&
429 	    in->isint == (mp->m_sb.sb_logstart != 0))
430 		return XFS_ERROR(EINVAL);
431 	/*
432 	 * Moving the log is hard, need new interfaces to sync
433 	 * the log first, hold off all activity while moving it.
434 	 * Can have shorter or longer log in the same space,
435 	 * or transform internal to external log or vice versa.
436 	 */
437 	return XFS_ERROR(ENOSYS);
438 }
439 
440 /*
441  * protected versions of growfs function acquire and release locks on the mount
442  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
443  * XFS_IOC_FSGROWFSRT
444  */
445 
446 
447 int
448 xfs_growfs_data(
449 	xfs_mount_t		*mp,
450 	xfs_growfs_data_t	*in)
451 {
452 	int error;
453 	if (!cpsema(&mp->m_growlock))
454 		return XFS_ERROR(EWOULDBLOCK);
455 	error = xfs_growfs_data_private(mp, in);
456 	vsema(&mp->m_growlock);
457 	return error;
458 }
459 
460 int
461 xfs_growfs_log(
462 	xfs_mount_t		*mp,
463 	xfs_growfs_log_t	*in)
464 {
465 	int error;
466 	if (!cpsema(&mp->m_growlock))
467 		return XFS_ERROR(EWOULDBLOCK);
468 	error = xfs_growfs_log_private(mp, in);
469 	vsema(&mp->m_growlock);
470 	return error;
471 }
472 
473 /*
474  * exported through ioctl XFS_IOC_FSCOUNTS
475  */
476 
477 int
478 xfs_fs_counts(
479 	xfs_mount_t		*mp,
480 	xfs_fsop_counts_t	*cnt)
481 {
482 	unsigned long	s;
483 
484 	s = XFS_SB_LOCK(mp);
485 	cnt->freedata = mp->m_sb.sb_fdblocks;
486 	cnt->freertx = mp->m_sb.sb_frextents;
487 	cnt->freeino = mp->m_sb.sb_ifree;
488 	cnt->allocino = mp->m_sb.sb_icount;
489 	XFS_SB_UNLOCK(mp, s);
490 	return 0;
491 }
492 
493 /*
494  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
495  *
496  * xfs_reserve_blocks is called to set m_resblks
497  * in the in-core mount table. The number of unused reserved blocks
498  * is kept in m_resbls_avail.
499  *
500  * Reserve the requested number of blocks if available. Otherwise return
501  * as many as possible to satisfy the request. The actual number
502  * reserved are returned in outval
503  *
504  * A null inval pointer indicates that only the current reserved blocks
505  * available  should  be returned no settings are changed.
506  */
507 
508 int
509 xfs_reserve_blocks(
510 	xfs_mount_t             *mp,
511 	__uint64_t              *inval,
512 	xfs_fsop_resblks_t      *outval)
513 {
514 	__int64_t		lcounter, delta;
515 	__uint64_t		request;
516 	unsigned long		s;
517 
518 	/* If inval is null, report current values and return */
519 
520 	if (inval == (__uint64_t *)NULL) {
521 		outval->resblks = mp->m_resblks;
522 		outval->resblks_avail = mp->m_resblks_avail;
523 		return(0);
524 	}
525 
526 	request = *inval;
527 	s = XFS_SB_LOCK(mp);
528 
529 	/*
530 	 * If our previous reservation was larger than the current value,
531 	 * then move any unused blocks back to the free pool.
532 	 */
533 
534 	if (mp->m_resblks > request) {
535 		lcounter = mp->m_resblks_avail - request;
536 		if (lcounter  > 0) {		/* release unused blocks */
537 			mp->m_sb.sb_fdblocks += lcounter;
538 			mp->m_resblks_avail -= lcounter;
539 		}
540 		mp->m_resblks = request;
541 	} else {
542 		delta = request - mp->m_resblks;
543 		lcounter = mp->m_sb.sb_fdblocks - delta;
544 		if (lcounter < 0) {
545 			/* We can't satisfy the request, just get what we can */
546 			mp->m_resblks += mp->m_sb.sb_fdblocks;
547 			mp->m_resblks_avail += mp->m_sb.sb_fdblocks;
548 			mp->m_sb.sb_fdblocks = 0;
549 		} else {
550 			mp->m_sb.sb_fdblocks = lcounter;
551 			mp->m_resblks = request;
552 			mp->m_resblks_avail += delta;
553 		}
554 	}
555 
556 	outval->resblks = mp->m_resblks;
557 	outval->resblks_avail = mp->m_resblks_avail;
558 	XFS_SB_UNLOCK(mp, s);
559 	return(0);
560 }
561 
562 void
563 xfs_fs_log_dummy(xfs_mount_t *mp)
564 {
565 	xfs_trans_t *tp;
566 	xfs_inode_t *ip;
567 
568 
569 	tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
570 	atomic_inc(&mp->m_active_trans);
571 	if (xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0)) {
572 		xfs_trans_cancel(tp, 0);
573 		return;
574 	}
575 
576 	ip = mp->m_rootip;
577 	xfs_ilock(ip, XFS_ILOCK_EXCL);
578 
579 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
580 	xfs_trans_ihold(tp, ip);
581 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
582 	xfs_trans_set_sync(tp);
583 	xfs_trans_commit(tp, 0, NULL);
584 
585 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
586 }
587 
588 int
589 xfs_fs_goingdown(
590 	xfs_mount_t	*mp,
591 	__uint32_t	inflags)
592 {
593 	switch (inflags) {
594 	case XFS_FSOP_GOING_FLAGS_DEFAULT: {
595 		struct vfs *vfsp = XFS_MTOVFS(mp);
596 		struct super_block *sb = freeze_bdev(vfsp->vfs_super->s_bdev);
597 
598 		if (sb) {
599 			xfs_force_shutdown(mp, XFS_FORCE_UMOUNT);
600 			thaw_bdev(sb->s_bdev, sb);
601 		}
602 
603 		break;
604 	}
605 	case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
606 		xfs_force_shutdown(mp, XFS_FORCE_UMOUNT);
607 		break;
608 	case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
609 		xfs_force_shutdown(mp, XFS_FORCE_UMOUNT|XFS_LOG_IO_ERROR);
610 		break;
611 	default:
612 		return XFS_ERROR(EINVAL);
613 	}
614 
615 	return 0;
616 }
617