Pull fsys_gettimeofday into release branch
[linux-2.6] / fs / xfs / xfs_fsops.c
1 /*
2  * Copyright (c) 2000-2005 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_inum.h"
23 #include "xfs_log.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_bmap_btree.h"
31 #include "xfs_alloc_btree.h"
32 #include "xfs_ialloc_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_btree.h"
39 #include "xfs_error.h"
40 #include "xfs_alloc.h"
41 #include "xfs_ialloc.h"
42 #include "xfs_fsops.h"
43 #include "xfs_itable.h"
44 #include "xfs_trans_space.h"
45 #include "xfs_rtalloc.h"
46 #include "xfs_rw.h"
47 #include "xfs_filestream.h"
48
49 /*
50  * File system operations
51  */
52
53 int
54 xfs_fs_geometry(
55         xfs_mount_t             *mp,
56         xfs_fsop_geom_t         *geo,
57         int                     new_version)
58 {
59         geo->blocksize = mp->m_sb.sb_blocksize;
60         geo->rtextsize = mp->m_sb.sb_rextsize;
61         geo->agblocks = mp->m_sb.sb_agblocks;
62         geo->agcount = mp->m_sb.sb_agcount;
63         geo->logblocks = mp->m_sb.sb_logblocks;
64         geo->sectsize = mp->m_sb.sb_sectsize;
65         geo->inodesize = mp->m_sb.sb_inodesize;
66         geo->imaxpct = mp->m_sb.sb_imax_pct;
67         geo->datablocks = mp->m_sb.sb_dblocks;
68         geo->rtblocks = mp->m_sb.sb_rblocks;
69         geo->rtextents = mp->m_sb.sb_rextents;
70         geo->logstart = mp->m_sb.sb_logstart;
71         ASSERT(sizeof(geo->uuid)==sizeof(mp->m_sb.sb_uuid));
72         memcpy(geo->uuid, &mp->m_sb.sb_uuid, sizeof(mp->m_sb.sb_uuid));
73         if (new_version >= 2) {
74                 geo->sunit = mp->m_sb.sb_unit;
75                 geo->swidth = mp->m_sb.sb_width;
76         }
77         if (new_version >= 3) {
78                 geo->version = XFS_FSOP_GEOM_VERSION;
79                 geo->flags =
80                         (xfs_sb_version_hasattr(&mp->m_sb) ?
81                                 XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
82                         (xfs_sb_version_hasnlink(&mp->m_sb) ?
83                                 XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
84                         (xfs_sb_version_hasquota(&mp->m_sb) ?
85                                 XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
86                         (xfs_sb_version_hasalign(&mp->m_sb) ?
87                                 XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
88                         (xfs_sb_version_hasdalign(&mp->m_sb) ?
89                                 XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
90                         (xfs_sb_version_hasshared(&mp->m_sb) ?
91                                 XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
92                         (xfs_sb_version_hasextflgbit(&mp->m_sb) ?
93                                 XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
94                         (xfs_sb_version_hasdirv2(&mp->m_sb) ?
95                                 XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
96                         (xfs_sb_version_hassector(&mp->m_sb) ?
97                                 XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
98                         (xfs_sb_version_haslazysbcount(&mp->m_sb) ?
99                                 XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
100                         (xfs_sb_version_hasattr2(&mp->m_sb) ?
101                                 XFS_FSOP_GEOM_FLAGS_ATTR2 : 0);
102                 geo->logsectsize = xfs_sb_version_hassector(&mp->m_sb) ?
103                                 mp->m_sb.sb_logsectsize : BBSIZE;
104                 geo->rtsectsize = mp->m_sb.sb_blocksize;
105                 geo->dirblocksize = mp->m_dirblksize;
106         }
107         if (new_version >= 4) {
108                 geo->flags |=
109                         (xfs_sb_version_haslogv2(&mp->m_sb) ?
110                                 XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
111                 geo->logsunit = mp->m_sb.sb_logsunit;
112         }
113         return 0;
114 }
115
116 static int
117 xfs_growfs_data_private(
118         xfs_mount_t             *mp,            /* mount point for filesystem */
119         xfs_growfs_data_t       *in)            /* growfs data input struct */
120 {
121         xfs_agf_t               *agf;
122         xfs_agi_t               *agi;
123         xfs_agnumber_t          agno;
124         xfs_extlen_t            agsize;
125         xfs_extlen_t            tmpsize;
126         xfs_alloc_rec_t         *arec;
127         xfs_btree_sblock_t      *block;
128         xfs_buf_t               *bp;
129         int                     bucket;
130         int                     dpct;
131         int                     error;
132         xfs_agnumber_t          nagcount;
133         xfs_agnumber_t          nagimax = 0;
134         xfs_rfsblock_t          nb, nb_mod;
135         xfs_rfsblock_t          new;
136         xfs_rfsblock_t          nfree;
137         xfs_agnumber_t          oagcount;
138         int                     pct;
139         xfs_trans_t             *tp;
140
141         nb = in->newblocks;
142         pct = in->imaxpct;
143         if (nb < mp->m_sb.sb_dblocks || pct < 0 || pct > 100)
144                 return XFS_ERROR(EINVAL);
145         if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
146                 return error;
147         dpct = pct - mp->m_sb.sb_imax_pct;
148         error = xfs_read_buf(mp, mp->m_ddev_targp,
149                         XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
150                         XFS_FSS_TO_BB(mp, 1), 0, &bp);
151         if (error)
152                 return error;
153         ASSERT(bp);
154         xfs_buf_relse(bp);
155
156         new = nb;       /* use new as a temporary here */
157         nb_mod = do_div(new, mp->m_sb.sb_agblocks);
158         nagcount = new + (nb_mod != 0);
159         if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
160                 nagcount--;
161                 nb = nagcount * mp->m_sb.sb_agblocks;
162                 if (nb < mp->m_sb.sb_dblocks)
163                         return XFS_ERROR(EINVAL);
164         }
165         new = nb - mp->m_sb.sb_dblocks;
166         oagcount = mp->m_sb.sb_agcount;
167         if (nagcount > oagcount) {
168                 xfs_filestream_flush(mp);
169                 down_write(&mp->m_peraglock);
170                 mp->m_perag = kmem_realloc(mp->m_perag,
171                         sizeof(xfs_perag_t) * nagcount,
172                         sizeof(xfs_perag_t) * oagcount,
173                         KM_SLEEP);
174                 memset(&mp->m_perag[oagcount], 0,
175                         (nagcount - oagcount) * sizeof(xfs_perag_t));
176                 mp->m_flags |= XFS_MOUNT_32BITINODES;
177                 nagimax = xfs_initialize_perag(mp, nagcount);
178                 up_write(&mp->m_peraglock);
179         }
180         tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
181         tp->t_flags |= XFS_TRANS_RESERVE;
182         if ((error = xfs_trans_reserve(tp, XFS_GROWFS_SPACE_RES(mp),
183                         XFS_GROWDATA_LOG_RES(mp), 0, 0, 0))) {
184                 xfs_trans_cancel(tp, 0);
185                 return error;
186         }
187
188         nfree = 0;
189         for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
190                 /*
191                  * AG freelist header block
192                  */
193                 bp = xfs_buf_get(mp->m_ddev_targp,
194                                   XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
195                                   XFS_FSS_TO_BB(mp, 1), 0);
196                 agf = XFS_BUF_TO_AGF(bp);
197                 memset(agf, 0, mp->m_sb.sb_sectsize);
198                 agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
199                 agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
200                 agf->agf_seqno = cpu_to_be32(agno);
201                 if (agno == nagcount - 1)
202                         agsize =
203                                 nb -
204                                 (agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
205                 else
206                         agsize = mp->m_sb.sb_agblocks;
207                 agf->agf_length = cpu_to_be32(agsize);
208                 agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
209                 agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
210                 agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
211                 agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
212                 agf->agf_flfirst = 0;
213                 agf->agf_fllast = cpu_to_be32(XFS_AGFL_SIZE(mp) - 1);
214                 agf->agf_flcount = 0;
215                 tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
216                 agf->agf_freeblks = cpu_to_be32(tmpsize);
217                 agf->agf_longest = cpu_to_be32(tmpsize);
218                 error = xfs_bwrite(mp, bp);
219                 if (error) {
220                         goto error0;
221                 }
222                 /*
223                  * AG inode header block
224                  */
225                 bp = xfs_buf_get(mp->m_ddev_targp,
226                                   XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
227                                   XFS_FSS_TO_BB(mp, 1), 0);
228                 agi = XFS_BUF_TO_AGI(bp);
229                 memset(agi, 0, mp->m_sb.sb_sectsize);
230                 agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
231                 agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
232                 agi->agi_seqno = cpu_to_be32(agno);
233                 agi->agi_length = cpu_to_be32(agsize);
234                 agi->agi_count = 0;
235                 agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
236                 agi->agi_level = cpu_to_be32(1);
237                 agi->agi_freecount = 0;
238                 agi->agi_newino = cpu_to_be32(NULLAGINO);
239                 agi->agi_dirino = cpu_to_be32(NULLAGINO);
240                 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
241                         agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
242                 error = xfs_bwrite(mp, bp);
243                 if (error) {
244                         goto error0;
245                 }
246                 /*
247                  * BNO btree root block
248                  */
249                 bp = xfs_buf_get(mp->m_ddev_targp,
250                         XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
251                         BTOBB(mp->m_sb.sb_blocksize), 0);
252                 block = XFS_BUF_TO_SBLOCK(bp);
253                 memset(block, 0, mp->m_sb.sb_blocksize);
254                 block->bb_magic = cpu_to_be32(XFS_ABTB_MAGIC);
255                 block->bb_level = 0;
256                 block->bb_numrecs = cpu_to_be16(1);
257                 block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
258                 block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
259                 arec = XFS_BTREE_REC_ADDR(xfs_alloc, block, 1);
260                 arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
261                 arec->ar_blockcount = cpu_to_be32(
262                         agsize - be32_to_cpu(arec->ar_startblock));
263                 error = xfs_bwrite(mp, bp);
264                 if (error) {
265                         goto error0;
266                 }
267                 /*
268                  * CNT btree root block
269                  */
270                 bp = xfs_buf_get(mp->m_ddev_targp,
271                         XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
272                         BTOBB(mp->m_sb.sb_blocksize), 0);
273                 block = XFS_BUF_TO_SBLOCK(bp);
274                 memset(block, 0, mp->m_sb.sb_blocksize);
275                 block->bb_magic = cpu_to_be32(XFS_ABTC_MAGIC);
276                 block->bb_level = 0;
277                 block->bb_numrecs = cpu_to_be16(1);
278                 block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
279                 block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
280                 arec = XFS_BTREE_REC_ADDR(xfs_alloc, block, 1);
281                 arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
282                 arec->ar_blockcount = cpu_to_be32(
283                         agsize - be32_to_cpu(arec->ar_startblock));
284                 nfree += be32_to_cpu(arec->ar_blockcount);
285                 error = xfs_bwrite(mp, bp);
286                 if (error) {
287                         goto error0;
288                 }
289                 /*
290                  * INO btree root block
291                  */
292                 bp = xfs_buf_get(mp->m_ddev_targp,
293                         XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
294                         BTOBB(mp->m_sb.sb_blocksize), 0);
295                 block = XFS_BUF_TO_SBLOCK(bp);
296                 memset(block, 0, mp->m_sb.sb_blocksize);
297                 block->bb_magic = cpu_to_be32(XFS_IBT_MAGIC);
298                 block->bb_level = 0;
299                 block->bb_numrecs = 0;
300                 block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
301                 block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
302                 error = xfs_bwrite(mp, bp);
303                 if (error) {
304                         goto error0;
305                 }
306         }
307         xfs_trans_agblocks_delta(tp, nfree);
308         /*
309          * There are new blocks in the old last a.g.
310          */
311         if (new) {
312                 /*
313                  * Change the agi length.
314                  */
315                 error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
316                 if (error) {
317                         goto error0;
318                 }
319                 ASSERT(bp);
320                 agi = XFS_BUF_TO_AGI(bp);
321                 be32_add_cpu(&agi->agi_length, new);
322                 ASSERT(nagcount == oagcount ||
323                        be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
324                 xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
325                 /*
326                  * Change agf length.
327                  */
328                 error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
329                 if (error) {
330                         goto error0;
331                 }
332                 ASSERT(bp);
333                 agf = XFS_BUF_TO_AGF(bp);
334                 be32_add_cpu(&agf->agf_length, new);
335                 ASSERT(be32_to_cpu(agf->agf_length) ==
336                        be32_to_cpu(agi->agi_length));
337                 xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
338                 /*
339                  * Free the new space.
340                  */
341                 error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
342                         be32_to_cpu(agf->agf_length) - new), new);
343                 if (error) {
344                         goto error0;
345                 }
346         }
347         if (nagcount > oagcount)
348                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
349         if (nb > mp->m_sb.sb_dblocks)
350                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
351                                  nb - mp->m_sb.sb_dblocks);
352         if (nfree)
353                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
354         if (dpct)
355                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
356         error = xfs_trans_commit(tp, 0);
357         if (error) {
358                 return error;
359         }
360         /* New allocation groups fully initialized, so update mount struct */
361         if (nagimax)
362                 mp->m_maxagi = nagimax;
363         if (mp->m_sb.sb_imax_pct) {
364                 __uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
365                 do_div(icount, 100);
366                 mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
367         } else
368                 mp->m_maxicount = 0;
369         for (agno = 1; agno < nagcount; agno++) {
370                 error = xfs_read_buf(mp, mp->m_ddev_targp,
371                                   XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
372                                   XFS_FSS_TO_BB(mp, 1), 0, &bp);
373                 if (error) {
374                         xfs_fs_cmn_err(CE_WARN, mp,
375                         "error %d reading secondary superblock for ag %d",
376                                 error, agno);
377                         break;
378                 }
379                 xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
380                 /*
381                  * If we get an error writing out the alternate superblocks,
382                  * just issue a warning and continue.  The real work is
383                  * already done and committed.
384                  */
385                 if (!(error = xfs_bwrite(mp, bp))) {
386                         continue;
387                 } else {
388                         xfs_fs_cmn_err(CE_WARN, mp,
389                 "write error %d updating secondary superblock for ag %d",
390                                 error, agno);
391                         break; /* no point in continuing */
392                 }
393         }
394         return 0;
395
396  error0:
397         xfs_trans_cancel(tp, XFS_TRANS_ABORT);
398         return error;
399 }
400
401 static int
402 xfs_growfs_log_private(
403         xfs_mount_t             *mp,    /* mount point for filesystem */
404         xfs_growfs_log_t        *in)    /* growfs log input struct */
405 {
406         xfs_extlen_t            nb;
407
408         nb = in->newblocks;
409         if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
410                 return XFS_ERROR(EINVAL);
411         if (nb == mp->m_sb.sb_logblocks &&
412             in->isint == (mp->m_sb.sb_logstart != 0))
413                 return XFS_ERROR(EINVAL);
414         /*
415          * Moving the log is hard, need new interfaces to sync
416          * the log first, hold off all activity while moving it.
417          * Can have shorter or longer log in the same space,
418          * or transform internal to external log or vice versa.
419          */
420         return XFS_ERROR(ENOSYS);
421 }
422
423 /*
424  * protected versions of growfs function acquire and release locks on the mount
425  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
426  * XFS_IOC_FSGROWFSRT
427  */
428
429
430 int
431 xfs_growfs_data(
432         xfs_mount_t             *mp,
433         xfs_growfs_data_t       *in)
434 {
435         int error;
436         if (!mutex_trylock(&mp->m_growlock))
437                 return XFS_ERROR(EWOULDBLOCK);
438         error = xfs_growfs_data_private(mp, in);
439         mutex_unlock(&mp->m_growlock);
440         return error;
441 }
442
443 int
444 xfs_growfs_log(
445         xfs_mount_t             *mp,
446         xfs_growfs_log_t        *in)
447 {
448         int error;
449         if (!mutex_trylock(&mp->m_growlock))
450                 return XFS_ERROR(EWOULDBLOCK);
451         error = xfs_growfs_log_private(mp, in);
452         mutex_unlock(&mp->m_growlock);
453         return error;
454 }
455
456 /*
457  * exported through ioctl XFS_IOC_FSCOUNTS
458  */
459
460 int
461 xfs_fs_counts(
462         xfs_mount_t             *mp,
463         xfs_fsop_counts_t       *cnt)
464 {
465         xfs_icsb_sync_counters_flags(mp, XFS_ICSB_LAZY_COUNT);
466         spin_lock(&mp->m_sb_lock);
467         cnt->freedata = mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
468         cnt->freertx = mp->m_sb.sb_frextents;
469         cnt->freeino = mp->m_sb.sb_ifree;
470         cnt->allocino = mp->m_sb.sb_icount;
471         spin_unlock(&mp->m_sb_lock);
472         return 0;
473 }
474
475 /*
476  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
477  *
478  * xfs_reserve_blocks is called to set m_resblks
479  * in the in-core mount table. The number of unused reserved blocks
480  * is kept in m_resblks_avail.
481  *
482  * Reserve the requested number of blocks if available. Otherwise return
483  * as many as possible to satisfy the request. The actual number
484  * reserved are returned in outval
485  *
486  * A null inval pointer indicates that only the current reserved blocks
487  * available  should  be returned no settings are changed.
488  */
489
490 int
491 xfs_reserve_blocks(
492         xfs_mount_t             *mp,
493         __uint64_t              *inval,
494         xfs_fsop_resblks_t      *outval)
495 {
496         __int64_t               lcounter, delta, fdblks_delta;
497         __uint64_t              request;
498
499         /* If inval is null, report current values and return */
500         if (inval == (__uint64_t *)NULL) {
501                 if (!outval)
502                         return EINVAL;
503                 outval->resblks = mp->m_resblks;
504                 outval->resblks_avail = mp->m_resblks_avail;
505                 return 0;
506         }
507
508         request = *inval;
509
510         /*
511          * With per-cpu counters, this becomes an interesting
512          * problem. we needto work out if we are freeing or allocation
513          * blocks first, then we can do the modification as necessary.
514          *
515          * We do this under the m_sb_lock so that if we are near
516          * ENOSPC, we will hold out any changes while we work out
517          * what to do. This means that the amount of free space can
518          * change while we do this, so we need to retry if we end up
519          * trying to reserve more space than is available.
520          *
521          * We also use the xfs_mod_incore_sb() interface so that we
522          * don't have to care about whether per cpu counter are
523          * enabled, disabled or even compiled in....
524          */
525 retry:
526         spin_lock(&mp->m_sb_lock);
527         xfs_icsb_sync_counters_flags(mp, XFS_ICSB_SB_LOCKED);
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         fdblks_delta = 0;
534         if (mp->m_resblks > request) {
535                 lcounter = mp->m_resblks_avail - request;
536                 if (lcounter  > 0) {            /* release unused blocks */
537                         fdblks_delta = lcounter;
538                         mp->m_resblks_avail -= lcounter;
539                 }
540                 mp->m_resblks = request;
541         } else {
542                 __int64_t       free;
543
544                 free =  mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
545                 if (!free)
546                         goto out; /* ENOSPC and fdblks_delta = 0 */
547
548                 delta = request - mp->m_resblks;
549                 lcounter = free - delta;
550                 if (lcounter < 0) {
551                         /* We can't satisfy the request, just get what we can */
552                         mp->m_resblks += free;
553                         mp->m_resblks_avail += free;
554                         fdblks_delta = -free;
555                         mp->m_sb.sb_fdblocks = XFS_ALLOC_SET_ASIDE(mp);
556                 } else {
557                         fdblks_delta = -delta;
558                         mp->m_sb.sb_fdblocks =
559                                 lcounter + XFS_ALLOC_SET_ASIDE(mp);
560                         mp->m_resblks = request;
561                         mp->m_resblks_avail += delta;
562                 }
563         }
564 out:
565         if (outval) {
566                 outval->resblks = mp->m_resblks;
567                 outval->resblks_avail = mp->m_resblks_avail;
568         }
569         spin_unlock(&mp->m_sb_lock);
570
571         if (fdblks_delta) {
572                 /*
573                  * If we are putting blocks back here, m_resblks_avail is
574                  * already at it's max so this will put it in the free pool.
575                  *
576                  * If we need space, we'll either succeed in getting it
577                  * from the free block count or we'll get an enospc. If
578                  * we get a ENOSPC, it means things changed while we were
579                  * calculating fdblks_delta and so we should try again to
580                  * see if there is anything left to reserve.
581                  *
582                  * Don't set the reserved flag here - we don't want to reserve
583                  * the extra reserve blocks from the reserve.....
584                  */
585                 int error;
586                 error = xfs_mod_incore_sb(mp, XFS_SBS_FDBLOCKS, fdblks_delta, 0);
587                 if (error == ENOSPC)
588                         goto retry;
589         }
590
591         return 0;
592 }
593
594 void
595 xfs_fs_log_dummy(
596         xfs_mount_t     *mp)
597 {
598         xfs_trans_t     *tp;
599         xfs_inode_t     *ip;
600
601         tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
602         if (xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0)) {
603                 xfs_trans_cancel(tp, 0);
604                 return;
605         }
606
607         ip = mp->m_rootip;
608         xfs_ilock(ip, XFS_ILOCK_EXCL);
609
610         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
611         xfs_trans_ihold(tp, ip);
612         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
613         xfs_trans_set_sync(tp);
614         xfs_trans_commit(tp, 0);
615
616         xfs_iunlock(ip, XFS_ILOCK_EXCL);
617 }
618
619 int
620 xfs_fs_goingdown(
621         xfs_mount_t     *mp,
622         __uint32_t      inflags)
623 {
624         switch (inflags) {
625         case XFS_FSOP_GOING_FLAGS_DEFAULT: {
626                 struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
627
628                 if (sb && !IS_ERR(sb)) {
629                         xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
630                         thaw_bdev(sb->s_bdev, sb);
631                 }
632         
633                 break;
634         }
635         case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
636                 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
637                 break;
638         case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
639                 xfs_force_shutdown(mp,
640                                 SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
641                 break;
642         default:
643                 return XFS_ERROR(EINVAL);
644         }
645
646         return 0;
647 }