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TOMOYO Linux Cross Reference
Linux/fs/xfs/xfs_bmap_util.c

Version: ~ [ linux-5.4-rc7 ] ~ [ linux-5.3.11 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.84 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.154 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.201 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.201 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.77 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
  3  * Copyright (c) 2012 Red Hat, Inc.
  4  * All Rights Reserved.
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License as
  8  * published by the Free Software Foundation.
  9  *
 10  * This program is distributed in the hope that it would be useful,
 11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13  * GNU General Public License for more details.
 14  *
 15  * You should have received a copy of the GNU General Public License
 16  * along with this program; if not, write the Free Software Foundation,
 17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 18  */
 19 #include "xfs.h"
 20 #include "xfs_fs.h"
 21 #include "xfs_shared.h"
 22 #include "xfs_format.h"
 23 #include "xfs_log_format.h"
 24 #include "xfs_trans_resv.h"
 25 #include "xfs_bit.h"
 26 #include "xfs_mount.h"
 27 #include "xfs_da_format.h"
 28 #include "xfs_inode.h"
 29 #include "xfs_btree.h"
 30 #include "xfs_trans.h"
 31 #include "xfs_extfree_item.h"
 32 #include "xfs_alloc.h"
 33 #include "xfs_bmap.h"
 34 #include "xfs_bmap_util.h"
 35 #include "xfs_bmap_btree.h"
 36 #include "xfs_rtalloc.h"
 37 #include "xfs_error.h"
 38 #include "xfs_quota.h"
 39 #include "xfs_trans_space.h"
 40 #include "xfs_trace.h"
 41 #include "xfs_icache.h"
 42 #include "xfs_log.h"
 43 
 44 /* Kernel only BMAP related definitions and functions */
 45 
 46 /*
 47  * Convert the given file system block to a disk block.  We have to treat it
 48  * differently based on whether the file is a real time file or not, because the
 49  * bmap code does.
 50  */
 51 xfs_daddr_t
 52 xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
 53 {
 54         return (XFS_IS_REALTIME_INODE(ip) ? \
 55                  (xfs_daddr_t)XFS_FSB_TO_BB((ip)->i_mount, (fsb)) : \
 56                  XFS_FSB_TO_DADDR((ip)->i_mount, (fsb)));
 57 }
 58 
 59 /*
 60  * Routine to zero an extent on disk allocated to the specific inode.
 61  *
 62  * The VFS functions take a linearised filesystem block offset, so we have to
 63  * convert the sparse xfs fsb to the right format first.
 64  * VFS types are real funky, too.
 65  */
 66 int
 67 xfs_zero_extent(
 68         struct xfs_inode *ip,
 69         xfs_fsblock_t   start_fsb,
 70         xfs_off_t       count_fsb)
 71 {
 72         struct xfs_mount *mp = ip->i_mount;
 73         xfs_daddr_t     sector = xfs_fsb_to_db(ip, start_fsb);
 74         sector_t        block = XFS_BB_TO_FSBT(mp, sector);
 75         ssize_t         size = XFS_FSB_TO_B(mp, count_fsb);
 76 
 77         if (IS_DAX(VFS_I(ip)))
 78                 return dax_clear_sectors(xfs_find_bdev_for_inode(VFS_I(ip)),
 79                                 sector, size);
 80 
 81         /*
 82          * let the block layer decide on the fastest method of
 83          * implementing the zeroing.
 84          */
 85         return sb_issue_zeroout(mp->m_super, block, count_fsb, GFP_NOFS);
 86 
 87 }
 88 
 89 /*
 90  * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
 91  * caller.  Frees all the extents that need freeing, which must be done
 92  * last due to locking considerations.  We never free any extents in
 93  * the first transaction.
 94  *
 95  * If an inode *ip is provided, rejoin it to the transaction if
 96  * the transaction was committed.
 97  */
 98 int                                             /* error */
 99 xfs_bmap_finish(
100         struct xfs_trans                **tp,   /* transaction pointer addr */
101         struct xfs_bmap_free            *flist, /* i/o: list extents to free */
102         struct xfs_inode                *ip)
103 {
104         struct xfs_efd_log_item         *efd;   /* extent free data */
105         struct xfs_efi_log_item         *efi;   /* extent free intention */
106         int                             error;  /* error return value */
107         int                             committed;/* xact committed or not */
108         struct xfs_bmap_free_item       *free;  /* free extent item */
109         struct xfs_bmap_free_item       *next;  /* next item on free list */
110 
111         ASSERT((*tp)->t_flags & XFS_TRANS_PERM_LOG_RES);
112         if (flist->xbf_count == 0)
113                 return 0;
114 
115         efi = xfs_trans_get_efi(*tp, flist->xbf_count);
116         for (free = flist->xbf_first; free; free = free->xbfi_next)
117                 xfs_trans_log_efi_extent(*tp, efi, free->xbfi_startblock,
118                         free->xbfi_blockcount);
119 
120         error = __xfs_trans_roll(tp, ip, &committed);
121         if (error) {
122                 /*
123                  * If the transaction was committed, drop the EFD reference
124                  * since we're bailing out of here. The other reference is
125                  * dropped when the EFI hits the AIL.
126                  *
127                  * If the transaction was not committed, the EFI is freed by the
128                  * EFI item unlock handler on abort. Also, we have a new
129                  * transaction so we should return committed=1 even though we're
130                  * returning an error.
131                  */
132                 if (committed) {
133                         xfs_efi_release(efi);
134                         xfs_force_shutdown((*tp)->t_mountp,
135                                 (error == -EFSCORRUPTED) ?
136                                         SHUTDOWN_CORRUPT_INCORE :
137                                         SHUTDOWN_META_IO_ERROR);
138                 }
139                 return error;
140         }
141 
142         /*
143          * Get an EFD and free each extent in the list, logging to the EFD in
144          * the process. The remaining bmap free list is cleaned up by the caller
145          * on error.
146          */
147         efd = xfs_trans_get_efd(*tp, efi, flist->xbf_count);
148         for (free = flist->xbf_first; free != NULL; free = next) {
149                 next = free->xbfi_next;
150 
151                 error = xfs_trans_free_extent(*tp, efd, free->xbfi_startblock,
152                                               free->xbfi_blockcount);
153                 if (error)
154                         return error;
155 
156                 xfs_bmap_del_free(flist, NULL, free);
157         }
158 
159         return 0;
160 }
161 
162 int
163 xfs_bmap_rtalloc(
164         struct xfs_bmalloca     *ap)    /* bmap alloc argument struct */
165 {
166         xfs_alloctype_t atype = 0;      /* type for allocation routines */
167         int             error;          /* error return value */
168         xfs_mount_t     *mp;            /* mount point structure */
169         xfs_extlen_t    prod = 0;       /* product factor for allocators */
170         xfs_extlen_t    ralen = 0;      /* realtime allocation length */
171         xfs_extlen_t    align;          /* minimum allocation alignment */
172         xfs_rtblock_t   rtb;
173 
174         mp = ap->ip->i_mount;
175         align = xfs_get_extsz_hint(ap->ip);
176         prod = align / mp->m_sb.sb_rextsize;
177         error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
178                                         align, 1, ap->eof, 0,
179                                         ap->conv, &ap->offset, &ap->length);
180         if (error)
181                 return error;
182         ASSERT(ap->length);
183         ASSERT(ap->length % mp->m_sb.sb_rextsize == 0);
184 
185         /*
186          * If the offset & length are not perfectly aligned
187          * then kill prod, it will just get us in trouble.
188          */
189         if (do_mod(ap->offset, align) || ap->length % align)
190                 prod = 1;
191         /*
192          * Set ralen to be the actual requested length in rtextents.
193          */
194         ralen = ap->length / mp->m_sb.sb_rextsize;
195         /*
196          * If the old value was close enough to MAXEXTLEN that
197          * we rounded up to it, cut it back so it's valid again.
198          * Note that if it's a really large request (bigger than
199          * MAXEXTLEN), we don't hear about that number, and can't
200          * adjust the starting point to match it.
201          */
202         if (ralen * mp->m_sb.sb_rextsize >= MAXEXTLEN)
203                 ralen = MAXEXTLEN / mp->m_sb.sb_rextsize;
204 
205         /*
206          * Lock out modifications to both the RT bitmap and summary inodes
207          */
208         xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
209         xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
210         xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL);
211         xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL);
212 
213         /*
214          * If it's an allocation to an empty file at offset 0,
215          * pick an extent that will space things out in the rt area.
216          */
217         if (ap->eof && ap->offset == 0) {
218                 xfs_rtblock_t uninitialized_var(rtx); /* realtime extent no */
219 
220                 error = xfs_rtpick_extent(mp, ap->tp, ralen, &rtx);
221                 if (error)
222                         return error;
223                 ap->blkno = rtx * mp->m_sb.sb_rextsize;
224         } else {
225                 ap->blkno = 0;
226         }
227 
228         xfs_bmap_adjacent(ap);
229 
230         /*
231          * Realtime allocation, done through xfs_rtallocate_extent.
232          */
233         atype = ap->blkno == 0 ?  XFS_ALLOCTYPE_ANY_AG : XFS_ALLOCTYPE_NEAR_BNO;
234         do_div(ap->blkno, mp->m_sb.sb_rextsize);
235         rtb = ap->blkno;
236         ap->length = ralen;
237         if ((error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1, ap->length,
238                                 &ralen, atype, ap->wasdel, prod, &rtb)))
239                 return error;
240         if (rtb == NULLFSBLOCK && prod > 1 &&
241             (error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1,
242                                            ap->length, &ralen, atype,
243                                            ap->wasdel, 1, &rtb)))
244                 return error;
245         ap->blkno = rtb;
246         if (ap->blkno != NULLFSBLOCK) {
247                 ap->blkno *= mp->m_sb.sb_rextsize;
248                 ralen *= mp->m_sb.sb_rextsize;
249                 ap->length = ralen;
250                 ap->ip->i_d.di_nblocks += ralen;
251                 xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
252                 if (ap->wasdel)
253                         ap->ip->i_delayed_blks -= ralen;
254                 /*
255                  * Adjust the disk quota also. This was reserved
256                  * earlier.
257                  */
258                 xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
259                         ap->wasdel ? XFS_TRANS_DQ_DELRTBCOUNT :
260                                         XFS_TRANS_DQ_RTBCOUNT, (long) ralen);
261 
262                 /* Zero the extent if we were asked to do so */
263                 if (ap->userdata & XFS_ALLOC_USERDATA_ZERO) {
264                         error = xfs_zero_extent(ap->ip, ap->blkno, ap->length);
265                         if (error)
266                                 return error;
267                 }
268         } else {
269                 ap->length = 0;
270         }
271         return 0;
272 }
273 
274 /*
275  * Check if the endoff is outside the last extent. If so the caller will grow
276  * the allocation to a stripe unit boundary.  All offsets are considered outside
277  * the end of file for an empty fork, so 1 is returned in *eof in that case.
278  */
279 int
280 xfs_bmap_eof(
281         struct xfs_inode        *ip,
282         xfs_fileoff_t           endoff,
283         int                     whichfork,
284         int                     *eof)
285 {
286         struct xfs_bmbt_irec    rec;
287         int                     error;
288 
289         error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, eof);
290         if (error || *eof)
291                 return error;
292 
293         *eof = endoff >= rec.br_startoff + rec.br_blockcount;
294         return 0;
295 }
296 
297 /*
298  * Extent tree block counting routines.
299  */
300 
301 /*
302  * Count leaf blocks given a range of extent records.
303  */
304 STATIC void
305 xfs_bmap_count_leaves(
306         xfs_ifork_t             *ifp,
307         xfs_extnum_t            idx,
308         int                     numrecs,
309         int                     *count)
310 {
311         int             b;
312 
313         for (b = 0; b < numrecs; b++) {
314                 xfs_bmbt_rec_host_t *frp = xfs_iext_get_ext(ifp, idx + b);
315                 *count += xfs_bmbt_get_blockcount(frp);
316         }
317 }
318 
319 /*
320  * Count leaf blocks given a range of extent records originally
321  * in btree format.
322  */
323 STATIC void
324 xfs_bmap_disk_count_leaves(
325         struct xfs_mount        *mp,
326         struct xfs_btree_block  *block,
327         int                     numrecs,
328         int                     *count)
329 {
330         int             b;
331         xfs_bmbt_rec_t  *frp;
332 
333         for (b = 1; b <= numrecs; b++) {
334                 frp = XFS_BMBT_REC_ADDR(mp, block, b);
335                 *count += xfs_bmbt_disk_get_blockcount(frp);
336         }
337 }
338 
339 /*
340  * Recursively walks each level of a btree
341  * to count total fsblocks in use.
342  */
343 STATIC int                                     /* error */
344 xfs_bmap_count_tree(
345         xfs_mount_t     *mp,            /* file system mount point */
346         xfs_trans_t     *tp,            /* transaction pointer */
347         xfs_ifork_t     *ifp,           /* inode fork pointer */
348         xfs_fsblock_t   blockno,        /* file system block number */
349         int             levelin,        /* level in btree */
350         int             *count)         /* Count of blocks */
351 {
352         int                     error;
353         xfs_buf_t               *bp, *nbp;
354         int                     level = levelin;
355         __be64                  *pp;
356         xfs_fsblock_t           bno = blockno;
357         xfs_fsblock_t           nextbno;
358         struct xfs_btree_block  *block, *nextblock;
359         int                     numrecs;
360 
361         error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp, XFS_BMAP_BTREE_REF,
362                                                 &xfs_bmbt_buf_ops);
363         if (error)
364                 return error;
365         *count += 1;
366         block = XFS_BUF_TO_BLOCK(bp);
367 
368         if (--level) {
369                 /* Not at node above leaves, count this level of nodes */
370                 nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
371                 while (nextbno != NULLFSBLOCK) {
372                         error = xfs_btree_read_bufl(mp, tp, nextbno, 0, &nbp,
373                                                 XFS_BMAP_BTREE_REF,
374                                                 &xfs_bmbt_buf_ops);
375                         if (error)
376                                 return error;
377                         *count += 1;
378                         nextblock = XFS_BUF_TO_BLOCK(nbp);
379                         nextbno = be64_to_cpu(nextblock->bb_u.l.bb_rightsib);
380                         xfs_trans_brelse(tp, nbp);
381                 }
382 
383                 /* Dive to the next level */
384                 pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
385                 bno = be64_to_cpu(*pp);
386                 if (unlikely((error =
387                      xfs_bmap_count_tree(mp, tp, ifp, bno, level, count)) < 0)) {
388                         xfs_trans_brelse(tp, bp);
389                         XFS_ERROR_REPORT("xfs_bmap_count_tree(1)",
390                                          XFS_ERRLEVEL_LOW, mp);
391                         return -EFSCORRUPTED;
392                 }
393                 xfs_trans_brelse(tp, bp);
394         } else {
395                 /* count all level 1 nodes and their leaves */
396                 for (;;) {
397                         nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
398                         numrecs = be16_to_cpu(block->bb_numrecs);
399                         xfs_bmap_disk_count_leaves(mp, block, numrecs, count);
400                         xfs_trans_brelse(tp, bp);
401                         if (nextbno == NULLFSBLOCK)
402                                 break;
403                         bno = nextbno;
404                         error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
405                                                 XFS_BMAP_BTREE_REF,
406                                                 &xfs_bmbt_buf_ops);
407                         if (error)
408                                 return error;
409                         *count += 1;
410                         block = XFS_BUF_TO_BLOCK(bp);
411                 }
412         }
413         return 0;
414 }
415 
416 /*
417  * Count fsblocks of the given fork.
418  */
419 int                                             /* error */
420 xfs_bmap_count_blocks(
421         xfs_trans_t             *tp,            /* transaction pointer */
422         xfs_inode_t             *ip,            /* incore inode */
423         int                     whichfork,      /* data or attr fork */
424         int                     *count)         /* out: count of blocks */
425 {
426         struct xfs_btree_block  *block; /* current btree block */
427         xfs_fsblock_t           bno;    /* block # of "block" */
428         xfs_ifork_t             *ifp;   /* fork structure */
429         int                     level;  /* btree level, for checking */
430         xfs_mount_t             *mp;    /* file system mount structure */
431         __be64                  *pp;    /* pointer to block address */
432 
433         bno = NULLFSBLOCK;
434         mp = ip->i_mount;
435         ifp = XFS_IFORK_PTR(ip, whichfork);
436         if ( XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS ) {
437                 xfs_bmap_count_leaves(ifp, 0,
438                         ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t),
439                         count);
440                 return 0;
441         }
442 
443         /*
444          * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
445          */
446         block = ifp->if_broot;
447         level = be16_to_cpu(block->bb_level);
448         ASSERT(level > 0);
449         pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
450         bno = be64_to_cpu(*pp);
451         ASSERT(bno != NULLFSBLOCK);
452         ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
453         ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
454 
455         if (unlikely(xfs_bmap_count_tree(mp, tp, ifp, bno, level, count) < 0)) {
456                 XFS_ERROR_REPORT("xfs_bmap_count_blocks(2)", XFS_ERRLEVEL_LOW,
457                                  mp);
458                 return -EFSCORRUPTED;
459         }
460 
461         return 0;
462 }
463 
464 /*
465  * returns 1 for success, 0 if we failed to map the extent.
466  */
467 STATIC int
468 xfs_getbmapx_fix_eof_hole(
469         xfs_inode_t             *ip,            /* xfs incore inode pointer */
470         struct getbmapx         *out,           /* output structure */
471         int                     prealloced,     /* this is a file with
472                                                  * preallocated data space */
473         __int64_t               end,            /* last block requested */
474         xfs_fsblock_t           startblock)
475 {
476         __int64_t               fixlen;
477         xfs_mount_t             *mp;            /* file system mount point */
478         xfs_ifork_t             *ifp;           /* inode fork pointer */
479         xfs_extnum_t            lastx;          /* last extent pointer */
480         xfs_fileoff_t           fileblock;
481 
482         if (startblock == HOLESTARTBLOCK) {
483                 mp = ip->i_mount;
484                 out->bmv_block = -1;
485                 fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
486                 fixlen -= out->bmv_offset;
487                 if (prealloced && out->bmv_offset + out->bmv_length == end) {
488                         /* Came to hole at EOF. Trim it. */
489                         if (fixlen <= 0)
490                                 return 0;
491                         out->bmv_length = fixlen;
492                 }
493         } else {
494                 if (startblock == DELAYSTARTBLOCK)
495                         out->bmv_block = -2;
496                 else
497                         out->bmv_block = xfs_fsb_to_db(ip, startblock);
498                 fileblock = XFS_BB_TO_FSB(ip->i_mount, out->bmv_offset);
499                 ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
500                 if (xfs_iext_bno_to_ext(ifp, fileblock, &lastx) &&
501                    (lastx == (ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t))-1))
502                         out->bmv_oflags |= BMV_OF_LAST;
503         }
504 
505         return 1;
506 }
507 
508 /*
509  * Get inode's extents as described in bmv, and format for output.
510  * Calls formatter to fill the user's buffer until all extents
511  * are mapped, until the passed-in bmv->bmv_count slots have
512  * been filled, or until the formatter short-circuits the loop,
513  * if it is tracking filled-in extents on its own.
514  */
515 int                                             /* error code */
516 xfs_getbmap(
517         xfs_inode_t             *ip,
518         struct getbmapx         *bmv,           /* user bmap structure */
519         xfs_bmap_format_t       formatter,      /* format to user */
520         void                    *arg)           /* formatter arg */
521 {
522         __int64_t               bmvend;         /* last block requested */
523         int                     error = 0;      /* return value */
524         __int64_t               fixlen;         /* length for -1 case */
525         int                     i;              /* extent number */
526         int                     lock;           /* lock state */
527         xfs_bmbt_irec_t         *map;           /* buffer for user's data */
528         xfs_mount_t             *mp;            /* file system mount point */
529         int                     nex;            /* # of user extents can do */
530         int                     nexleft;        /* # of user extents left */
531         int                     subnex;         /* # of bmapi's can do */
532         int                     nmap;           /* number of map entries */
533         struct getbmapx         *out;           /* output structure */
534         int                     whichfork;      /* data or attr fork */
535         int                     prealloced;     /* this is a file with
536                                                  * preallocated data space */
537         int                     iflags;         /* interface flags */
538         int                     bmapi_flags;    /* flags for xfs_bmapi */
539         int                     cur_ext = 0;
540 
541         mp = ip->i_mount;
542         iflags = bmv->bmv_iflags;
543         whichfork = iflags & BMV_IF_ATTRFORK ? XFS_ATTR_FORK : XFS_DATA_FORK;
544 
545         if (whichfork == XFS_ATTR_FORK) {
546                 if (XFS_IFORK_Q(ip)) {
547                         if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS &&
548                             ip->i_d.di_aformat != XFS_DINODE_FMT_BTREE &&
549                             ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)
550                                 return -EINVAL;
551                 } else if (unlikely(
552                            ip->i_d.di_aformat != 0 &&
553                            ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS)) {
554                         XFS_ERROR_REPORT("xfs_getbmap", XFS_ERRLEVEL_LOW,
555                                          ip->i_mount);
556                         return -EFSCORRUPTED;
557                 }
558 
559                 prealloced = 0;
560                 fixlen = 1LL << 32;
561         } else {
562                 if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
563                     ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
564                     ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
565                         return -EINVAL;
566 
567                 if (xfs_get_extsz_hint(ip) ||
568                     ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC|XFS_DIFLAG_APPEND)){
569                         prealloced = 1;
570                         fixlen = mp->m_super->s_maxbytes;
571                 } else {
572                         prealloced = 0;
573                         fixlen = XFS_ISIZE(ip);
574                 }
575         }
576 
577         if (bmv->bmv_length == -1) {
578                 fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, fixlen));
579                 bmv->bmv_length =
580                         max_t(__int64_t, fixlen - bmv->bmv_offset, 0);
581         } else if (bmv->bmv_length == 0) {
582                 bmv->bmv_entries = 0;
583                 return 0;
584         } else if (bmv->bmv_length < 0) {
585                 return -EINVAL;
586         }
587 
588         nex = bmv->bmv_count - 1;
589         if (nex <= 0)
590                 return -EINVAL;
591         bmvend = bmv->bmv_offset + bmv->bmv_length;
592 
593 
594         if (bmv->bmv_count > ULONG_MAX / sizeof(struct getbmapx))
595                 return -ENOMEM;
596         out = kmem_zalloc_large(bmv->bmv_count * sizeof(struct getbmapx), 0);
597         if (!out)
598                 return -ENOMEM;
599 
600         xfs_ilock(ip, XFS_IOLOCK_SHARED);
601         if (whichfork == XFS_DATA_FORK) {
602                 if (!(iflags & BMV_IF_DELALLOC) &&
603                     (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_d.di_size)) {
604                         error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
605                         if (error)
606                                 goto out_unlock_iolock;
607 
608                         /*
609                          * Even after flushing the inode, there can still be
610                          * delalloc blocks on the inode beyond EOF due to
611                          * speculative preallocation.  These are not removed
612                          * until the release function is called or the inode
613                          * is inactivated.  Hence we cannot assert here that
614                          * ip->i_delayed_blks == 0.
615                          */
616                 }
617 
618                 lock = xfs_ilock_data_map_shared(ip);
619         } else {
620                 lock = xfs_ilock_attr_map_shared(ip);
621         }
622 
623         /*
624          * Don't let nex be bigger than the number of extents
625          * we can have assuming alternating holes and real extents.
626          */
627         if (nex > XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1)
628                 nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1;
629 
630         bmapi_flags = xfs_bmapi_aflag(whichfork);
631         if (!(iflags & BMV_IF_PREALLOC))
632                 bmapi_flags |= XFS_BMAPI_IGSTATE;
633 
634         /*
635          * Allocate enough space to handle "subnex" maps at a time.
636          */
637         error = -ENOMEM;
638         subnex = 16;
639         map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL | KM_NOFS);
640         if (!map)
641                 goto out_unlock_ilock;
642 
643         bmv->bmv_entries = 0;
644 
645         if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0 &&
646             (whichfork == XFS_ATTR_FORK || !(iflags & BMV_IF_DELALLOC))) {
647                 error = 0;
648                 goto out_free_map;
649         }
650 
651         nexleft = nex;
652 
653         do {
654                 nmap = (nexleft > subnex) ? subnex : nexleft;
655                 error = xfs_bmapi_read(ip, XFS_BB_TO_FSBT(mp, bmv->bmv_offset),
656                                        XFS_BB_TO_FSB(mp, bmv->bmv_length),
657                                        map, &nmap, bmapi_flags);
658                 if (error)
659                         goto out_free_map;
660                 ASSERT(nmap <= subnex);
661 
662                 for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) {
663                         out[cur_ext].bmv_oflags = 0;
664                         if (map[i].br_state == XFS_EXT_UNWRITTEN)
665                                 out[cur_ext].bmv_oflags |= BMV_OF_PREALLOC;
666                         else if (map[i].br_startblock == DELAYSTARTBLOCK)
667                                 out[cur_ext].bmv_oflags |= BMV_OF_DELALLOC;
668                         out[cur_ext].bmv_offset =
669                                 XFS_FSB_TO_BB(mp, map[i].br_startoff);
670                         out[cur_ext].bmv_length =
671                                 XFS_FSB_TO_BB(mp, map[i].br_blockcount);
672                         out[cur_ext].bmv_unused1 = 0;
673                         out[cur_ext].bmv_unused2 = 0;
674 
675                         /*
676                          * delayed allocation extents that start beyond EOF can
677                          * occur due to speculative EOF allocation when the
678                          * delalloc extent is larger than the largest freespace
679                          * extent at conversion time. These extents cannot be
680                          * converted by data writeback, so can exist here even
681                          * if we are not supposed to be finding delalloc
682                          * extents.
683                          */
684                         if (map[i].br_startblock == DELAYSTARTBLOCK &&
685                             map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
686                                 ASSERT((iflags & BMV_IF_DELALLOC) != 0);
687 
688                         if (map[i].br_startblock == HOLESTARTBLOCK &&
689                             whichfork == XFS_ATTR_FORK) {
690                                 /* came to the end of attribute fork */
691                                 out[cur_ext].bmv_oflags |= BMV_OF_LAST;
692                                 goto out_free_map;
693                         }
694 
695                         if (!xfs_getbmapx_fix_eof_hole(ip, &out[cur_ext],
696                                         prealloced, bmvend,
697                                         map[i].br_startblock))
698                                 goto out_free_map;
699 
700                         bmv->bmv_offset =
701                                 out[cur_ext].bmv_offset +
702                                 out[cur_ext].bmv_length;
703                         bmv->bmv_length =
704                                 max_t(__int64_t, 0, bmvend - bmv->bmv_offset);
705 
706                         /*
707                          * In case we don't want to return the hole,
708                          * don't increase cur_ext so that we can reuse
709                          * it in the next loop.
710                          */
711                         if ((iflags & BMV_IF_NO_HOLES) &&
712                             map[i].br_startblock == HOLESTARTBLOCK) {
713                                 memset(&out[cur_ext], 0, sizeof(out[cur_ext]));
714                                 continue;
715                         }
716 
717                         nexleft--;
718                         bmv->bmv_entries++;
719                         cur_ext++;
720                 }
721         } while (nmap && nexleft && bmv->bmv_length);
722 
723  out_free_map:
724         kmem_free(map);
725  out_unlock_ilock:
726         xfs_iunlock(ip, lock);
727  out_unlock_iolock:
728         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
729 
730         for (i = 0; i < cur_ext; i++) {
731                 int full = 0;   /* user array is full */
732 
733                 /* format results & advance arg */
734                 error = formatter(&arg, &out[i], &full);
735                 if (error || full)
736                         break;
737         }
738 
739         kmem_free(out);
740         return error;
741 }
742 
743 /*
744  * dead simple method of punching delalyed allocation blocks from a range in
745  * the inode. Walks a block at a time so will be slow, but is only executed in
746  * rare error cases so the overhead is not critical. This will always punch out
747  * both the start and end blocks, even if the ranges only partially overlap
748  * them, so it is up to the caller to ensure that partial blocks are not
749  * passed in.
750  */
751 int
752 xfs_bmap_punch_delalloc_range(
753         struct xfs_inode        *ip,
754         xfs_fileoff_t           start_fsb,
755         xfs_fileoff_t           length)
756 {
757         xfs_fileoff_t           remaining = length;
758         int                     error = 0;
759 
760         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
761 
762         do {
763                 int             done;
764                 xfs_bmbt_irec_t imap;
765                 int             nimaps = 1;
766                 xfs_fsblock_t   firstblock;
767                 xfs_bmap_free_t flist;
768 
769                 /*
770                  * Map the range first and check that it is a delalloc extent
771                  * before trying to unmap the range. Otherwise we will be
772                  * trying to remove a real extent (which requires a
773                  * transaction) or a hole, which is probably a bad idea...
774                  */
775                 error = xfs_bmapi_read(ip, start_fsb, 1, &imap, &nimaps,
776                                        XFS_BMAPI_ENTIRE);
777 
778                 if (error) {
779                         /* something screwed, just bail */
780                         if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
781                                 xfs_alert(ip->i_mount,
782                         "Failed delalloc mapping lookup ino %lld fsb %lld.",
783                                                 ip->i_ino, start_fsb);
784                         }
785                         break;
786                 }
787                 if (!nimaps) {
788                         /* nothing there */
789                         goto next_block;
790                 }
791                 if (imap.br_startblock != DELAYSTARTBLOCK) {
792                         /* been converted, ignore */
793                         goto next_block;
794                 }
795                 WARN_ON(imap.br_blockcount == 0);
796 
797                 /*
798                  * Note: while we initialise the firstblock/flist pair, they
799                  * should never be used because blocks should never be
800                  * allocated or freed for a delalloc extent and hence we need
801                  * don't cancel or finish them after the xfs_bunmapi() call.
802                  */
803                 xfs_bmap_init(&flist, &firstblock);
804                 error = xfs_bunmapi(NULL, ip, start_fsb, 1, 0, 1, &firstblock,
805                                         &flist, &done);
806                 if (error)
807                         break;
808 
809                 ASSERT(!flist.xbf_count && !flist.xbf_first);
810 next_block:
811                 start_fsb++;
812                 remaining--;
813         } while(remaining > 0);
814 
815         return error;
816 }
817 
818 /*
819  * Test whether it is appropriate to check an inode for and free post EOF
820  * blocks. The 'force' parameter determines whether we should also consider
821  * regular files that are marked preallocated or append-only.
822  */
823 bool
824 xfs_can_free_eofblocks(struct xfs_inode *ip, bool force)
825 {
826         /* prealloc/delalloc exists only on regular files */
827         if (!S_ISREG(VFS_I(ip)->i_mode))
828                 return false;
829 
830         /*
831          * Zero sized files with no cached pages and delalloc blocks will not
832          * have speculative prealloc/delalloc blocks to remove.
833          */
834         if (VFS_I(ip)->i_size == 0 &&
835             VFS_I(ip)->i_mapping->nrpages == 0 &&
836             ip->i_delayed_blks == 0)
837                 return false;
838 
839         /* If we haven't read in the extent list, then don't do it now. */
840         if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
841                 return false;
842 
843         /*
844          * Do not free real preallocated or append-only files unless the file
845          * has delalloc blocks and we are forced to remove them.
846          */
847         if (ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
848                 if (!force || ip->i_delayed_blks == 0)
849                         return false;
850 
851         return true;
852 }
853 
854 /*
855  * This is called by xfs_inactive to free any blocks beyond eof
856  * when the link count isn't zero and by xfs_dm_punch_hole() when
857  * punching a hole to EOF.
858  */
859 int
860 xfs_free_eofblocks(
861         xfs_mount_t     *mp,
862         xfs_inode_t     *ip,
863         bool            need_iolock)
864 {
865         xfs_trans_t     *tp;
866         int             error;
867         xfs_fileoff_t   end_fsb;
868         xfs_fileoff_t   last_fsb;
869         xfs_filblks_t   map_len;
870         int             nimaps;
871         xfs_bmbt_irec_t imap;
872 
873         /*
874          * Figure out if there are any blocks beyond the end
875          * of the file.  If not, then there is nothing to do.
876          */
877         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
878         last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
879         if (last_fsb <= end_fsb)
880                 return 0;
881         map_len = last_fsb - end_fsb;
882 
883         nimaps = 1;
884         xfs_ilock(ip, XFS_ILOCK_SHARED);
885         error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0);
886         xfs_iunlock(ip, XFS_ILOCK_SHARED);
887 
888         if (!error && (nimaps != 0) &&
889             (imap.br_startblock != HOLESTARTBLOCK ||
890              ip->i_delayed_blks)) {
891                 /*
892                  * Attach the dquots to the inode up front.
893                  */
894                 error = xfs_qm_dqattach(ip, 0);
895                 if (error)
896                         return error;
897 
898                 /*
899                  * There are blocks after the end of file.
900                  * Free them up now by truncating the file to
901                  * its current size.
902                  */
903                 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
904 
905                 if (need_iolock) {
906                         if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
907                                 xfs_trans_cancel(tp);
908                                 return -EAGAIN;
909                         }
910                 }
911 
912                 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
913                 if (error) {
914                         ASSERT(XFS_FORCED_SHUTDOWN(mp));
915                         xfs_trans_cancel(tp);
916                         if (need_iolock)
917                                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
918                         return error;
919                 }
920 
921                 xfs_ilock(ip, XFS_ILOCK_EXCL);
922                 xfs_trans_ijoin(tp, ip, 0);
923 
924                 /*
925                  * Do not update the on-disk file size.  If we update the
926                  * on-disk file size and then the system crashes before the
927                  * contents of the file are flushed to disk then the files
928                  * may be full of holes (ie NULL files bug).
929                  */
930                 error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK,
931                                               XFS_ISIZE(ip));
932                 if (error) {
933                         /*
934                          * If we get an error at this point we simply don't
935                          * bother truncating the file.
936                          */
937                         xfs_trans_cancel(tp);
938                 } else {
939                         error = xfs_trans_commit(tp);
940                         if (!error)
941                                 xfs_inode_clear_eofblocks_tag(ip);
942                 }
943 
944                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
945                 if (need_iolock)
946                         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
947         }
948         return error;
949 }
950 
951 int
952 xfs_alloc_file_space(
953         struct xfs_inode        *ip,
954         xfs_off_t               offset,
955         xfs_off_t               len,
956         int                     alloc_type)
957 {
958         xfs_mount_t             *mp = ip->i_mount;
959         xfs_off_t               count;
960         xfs_filblks_t           allocated_fsb;
961         xfs_filblks_t           allocatesize_fsb;
962         xfs_extlen_t            extsz, temp;
963         xfs_fileoff_t           startoffset_fsb;
964         xfs_fsblock_t           firstfsb;
965         int                     nimaps;
966         int                     quota_flag;
967         int                     rt;
968         xfs_trans_t             *tp;
969         xfs_bmbt_irec_t         imaps[1], *imapp;
970         xfs_bmap_free_t         free_list;
971         uint                    qblocks, resblks, resrtextents;
972         int                     error;
973 
974         trace_xfs_alloc_file_space(ip);
975 
976         if (XFS_FORCED_SHUTDOWN(mp))
977                 return -EIO;
978 
979         error = xfs_qm_dqattach(ip, 0);
980         if (error)
981                 return error;
982 
983         if (len <= 0)
984                 return -EINVAL;
985 
986         rt = XFS_IS_REALTIME_INODE(ip);
987         extsz = xfs_get_extsz_hint(ip);
988 
989         count = len;
990         imapp = &imaps[0];
991         nimaps = 1;
992         startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
993         allocatesize_fsb = XFS_B_TO_FSB(mp, count);
994 
995         /*
996          * Allocate file space until done or until there is an error
997          */
998         while (allocatesize_fsb && !error) {
999                 xfs_fileoff_t   s, e;
1000 
1001                 /*
1002                  * Determine space reservations for data/realtime.
1003                  */
1004                 if (unlikely(extsz)) {
1005                         s = startoffset_fsb;
1006                         do_div(s, extsz);
1007                         s *= extsz;
1008                         e = startoffset_fsb + allocatesize_fsb;
1009                         if ((temp = do_mod(startoffset_fsb, extsz)))
1010                                 e += temp;
1011                         if ((temp = do_mod(e, extsz)))
1012                                 e += extsz - temp;
1013                 } else {
1014                         s = 0;
1015                         e = allocatesize_fsb;
1016                 }
1017 
1018                 /*
1019                  * The transaction reservation is limited to a 32-bit block
1020                  * count, hence we need to limit the number of blocks we are
1021                  * trying to reserve to avoid an overflow. We can't allocate
1022                  * more than @nimaps extents, and an extent is limited on disk
1023                  * to MAXEXTLEN (21 bits), so use that to enforce the limit.
1024                  */
1025                 resblks = min_t(xfs_fileoff_t, (e - s), (MAXEXTLEN * nimaps));
1026                 if (unlikely(rt)) {
1027                         resrtextents = qblocks = resblks;
1028                         resrtextents /= mp->m_sb.sb_rextsize;
1029                         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
1030                         quota_flag = XFS_QMOPT_RES_RTBLKS;
1031                 } else {
1032                         resrtextents = 0;
1033                         resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
1034                         quota_flag = XFS_QMOPT_RES_REGBLKS;
1035                 }
1036 
1037                 /*
1038                  * Allocate and setup the transaction.
1039                  */
1040                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
1041                 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
1042                                           resblks, resrtextents);
1043                 /*
1044                  * Check for running out of space
1045                  */
1046                 if (error) {
1047                         /*
1048                          * Free the transaction structure.
1049                          */
1050                         ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
1051                         xfs_trans_cancel(tp);
1052                         break;
1053                 }
1054                 xfs_ilock(ip, XFS_ILOCK_EXCL);
1055                 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks,
1056                                                       0, quota_flag);
1057                 if (error)
1058                         goto error1;
1059 
1060                 xfs_trans_ijoin(tp, ip, 0);
1061 
1062                 xfs_bmap_init(&free_list, &firstfsb);
1063                 error = xfs_bmapi_write(tp, ip, startoffset_fsb,
1064                                         allocatesize_fsb, alloc_type, &firstfsb,
1065                                         resblks, imapp, &nimaps, &free_list);
1066                 if (error)
1067                         goto error0;
1068 
1069                 /*
1070                  * Complete the transaction
1071                  */
1072                 error = xfs_bmap_finish(&tp, &free_list, NULL);
1073                 if (error)
1074                         goto error0;
1075 
1076                 error = xfs_trans_commit(tp);
1077                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1078                 if (error)
1079                         break;
1080 
1081                 allocated_fsb = imapp->br_blockcount;
1082 
1083                 if (nimaps == 0) {
1084                         error = -ENOSPC;
1085                         break;
1086                 }
1087 
1088                 startoffset_fsb += allocated_fsb;
1089                 allocatesize_fsb -= allocated_fsb;
1090         }
1091 
1092         return error;
1093 
1094 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
1095         xfs_bmap_cancel(&free_list);
1096         xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
1097 
1098 error1: /* Just cancel transaction */
1099         xfs_trans_cancel(tp);
1100         xfs_iunlock(ip, XFS_ILOCK_EXCL);
1101         return error;
1102 }
1103 
1104 /*
1105  * Zero file bytes between startoff and endoff inclusive.
1106  * The iolock is held exclusive and no blocks are buffered.
1107  *
1108  * This function is used by xfs_free_file_space() to zero
1109  * partial blocks when the range to free is not block aligned.
1110  * When unreserving space with boundaries that are not block
1111  * aligned we round up the start and round down the end
1112  * boundaries and then use this function to zero the parts of
1113  * the blocks that got dropped during the rounding.
1114  */
1115 STATIC int
1116 xfs_zero_remaining_bytes(
1117         xfs_inode_t             *ip,
1118         xfs_off_t               startoff,
1119         xfs_off_t               endoff)
1120 {
1121         xfs_bmbt_irec_t         imap;
1122         xfs_fileoff_t           offset_fsb;
1123         xfs_off_t               lastoffset;
1124         xfs_off_t               offset;
1125         xfs_buf_t               *bp;
1126         xfs_mount_t             *mp = ip->i_mount;
1127         int                     nimap;
1128         int                     error = 0;
1129 
1130         /*
1131          * Avoid doing I/O beyond eof - it's not necessary
1132          * since nothing can read beyond eof.  The space will
1133          * be zeroed when the file is extended anyway.
1134          */
1135         if (startoff >= XFS_ISIZE(ip))
1136                 return 0;
1137 
1138         if (endoff > XFS_ISIZE(ip))
1139                 endoff = XFS_ISIZE(ip);
1140 
1141         for (offset = startoff; offset <= endoff; offset = lastoffset + 1) {
1142                 uint lock_mode;
1143 
1144                 offset_fsb = XFS_B_TO_FSBT(mp, offset);
1145                 nimap = 1;
1146 
1147                 lock_mode = xfs_ilock_data_map_shared(ip);
1148                 error = xfs_bmapi_read(ip, offset_fsb, 1, &imap, &nimap, 0);
1149                 xfs_iunlock(ip, lock_mode);
1150 
1151                 if (error || nimap < 1)
1152                         break;
1153                 ASSERT(imap.br_blockcount >= 1);
1154                 ASSERT(imap.br_startoff == offset_fsb);
1155                 ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
1156 
1157                 if (imap.br_startblock == HOLESTARTBLOCK ||
1158                     imap.br_state == XFS_EXT_UNWRITTEN) {
1159                         /* skip the entire extent */
1160                         lastoffset = XFS_FSB_TO_B(mp, imap.br_startoff +
1161                                                       imap.br_blockcount) - 1;
1162                         continue;
1163                 }
1164 
1165                 lastoffset = XFS_FSB_TO_B(mp, imap.br_startoff + 1) - 1;
1166                 if (lastoffset > endoff)
1167                         lastoffset = endoff;
1168 
1169                 /* DAX can just zero the backing device directly */
1170                 if (IS_DAX(VFS_I(ip))) {
1171                         error = dax_zero_page_range(VFS_I(ip), offset,
1172                                                     lastoffset - offset + 1,
1173                                                     xfs_get_blocks_direct);
1174                         if (error)
1175                                 return error;
1176                         continue;
1177                 }
1178 
1179                 error = xfs_buf_read_uncached(XFS_IS_REALTIME_INODE(ip) ?
1180                                 mp->m_rtdev_targp : mp->m_ddev_targp,
1181                                 xfs_fsb_to_db(ip, imap.br_startblock),
1182                                 BTOBB(mp->m_sb.sb_blocksize),
1183                                 0, &bp, NULL);
1184                 if (error)
1185                         return error;
1186 
1187                 memset(bp->b_addr +
1188                                 (offset - XFS_FSB_TO_B(mp, imap.br_startoff)),
1189                        0, lastoffset - offset + 1);
1190 
1191                 error = xfs_bwrite(bp);
1192                 xfs_buf_relse(bp);
1193                 if (error)
1194                         return error;
1195         }
1196         return error;
1197 }
1198 
1199 int
1200 xfs_free_file_space(
1201         struct xfs_inode        *ip,
1202         xfs_off_t               offset,
1203         xfs_off_t               len)
1204 {
1205         int                     done;
1206         xfs_fileoff_t           endoffset_fsb;
1207         int                     error;
1208         xfs_fsblock_t           firstfsb;
1209         xfs_bmap_free_t         free_list;
1210         xfs_bmbt_irec_t         imap;
1211         xfs_off_t               ioffset;
1212         xfs_off_t               iendoffset;
1213         xfs_extlen_t            mod=0;
1214         xfs_mount_t             *mp;
1215         int                     nimap;
1216         uint                    resblks;
1217         xfs_off_t               rounding;
1218         int                     rt;
1219         xfs_fileoff_t           startoffset_fsb;
1220         xfs_trans_t             *tp;
1221 
1222         mp = ip->i_mount;
1223 
1224         trace_xfs_free_file_space(ip);
1225 
1226         error = xfs_qm_dqattach(ip, 0);
1227         if (error)
1228                 return error;
1229 
1230         error = 0;
1231         if (len <= 0)   /* if nothing being freed */
1232                 return error;
1233         rt = XFS_IS_REALTIME_INODE(ip);
1234         startoffset_fsb = XFS_B_TO_FSB(mp, offset);
1235         endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
1236 
1237         /* wait for the completion of any pending DIOs */
1238         inode_dio_wait(VFS_I(ip));
1239 
1240         rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_SIZE);
1241         ioffset = round_down(offset, rounding);
1242         iendoffset = round_up(offset + len, rounding) - 1;
1243         error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, ioffset,
1244                                              iendoffset);
1245         if (error)
1246                 goto out;
1247         truncate_pagecache_range(VFS_I(ip), ioffset, iendoffset);
1248 
1249         /*
1250          * Need to zero the stuff we're not freeing, on disk.
1251          * If it's a realtime file & can't use unwritten extents then we
1252          * actually need to zero the extent edges.  Otherwise xfs_bunmapi
1253          * will take care of it for us.
1254          */
1255         if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
1256                 nimap = 1;
1257                 error = xfs_bmapi_read(ip, startoffset_fsb, 1,
1258                                         &imap, &nimap, 0);
1259                 if (error)
1260                         goto out;
1261                 ASSERT(nimap == 0 || nimap == 1);
1262                 if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
1263                         xfs_daddr_t     block;
1264 
1265                         ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
1266                         block = imap.br_startblock;
1267                         mod = do_div(block, mp->m_sb.sb_rextsize);
1268                         if (mod)
1269                                 startoffset_fsb += mp->m_sb.sb_rextsize - mod;
1270                 }
1271                 nimap = 1;
1272                 error = xfs_bmapi_read(ip, endoffset_fsb - 1, 1,
1273                                         &imap, &nimap, 0);
1274                 if (error)
1275                         goto out;
1276                 ASSERT(nimap == 0 || nimap == 1);
1277                 if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
1278                         ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
1279                         mod++;
1280                         if (mod && (mod != mp->m_sb.sb_rextsize))
1281                                 endoffset_fsb -= mod;
1282                 }
1283         }
1284         if ((done = (endoffset_fsb <= startoffset_fsb)))
1285                 /*
1286                  * One contiguous piece to clear
1287                  */
1288                 error = xfs_zero_remaining_bytes(ip, offset, offset + len - 1);
1289         else {
1290                 /*
1291                  * Some full blocks, possibly two pieces to clear
1292                  */
1293                 if (offset < XFS_FSB_TO_B(mp, startoffset_fsb))
1294                         error = xfs_zero_remaining_bytes(ip, offset,
1295                                 XFS_FSB_TO_B(mp, startoffset_fsb) - 1);
1296                 if (!error &&
1297                     XFS_FSB_TO_B(mp, endoffset_fsb) < offset + len)
1298                         error = xfs_zero_remaining_bytes(ip,
1299                                 XFS_FSB_TO_B(mp, endoffset_fsb),
1300                                 offset + len - 1);
1301         }
1302 
1303         /*
1304          * free file space until done or until there is an error
1305          */
1306         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
1307         while (!error && !done) {
1308 
1309                 /*
1310                  * allocate and setup the transaction. Allow this
1311                  * transaction to dip into the reserve blocks to ensure
1312                  * the freeing of the space succeeds at ENOSPC.
1313                  */
1314                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
1315                 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write, resblks, 0);
1316 
1317                 /*
1318                  * check for running out of space
1319                  */
1320                 if (error) {
1321                         /*
1322                          * Free the transaction structure.
1323                          */
1324                         ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
1325                         xfs_trans_cancel(tp);
1326                         break;
1327                 }
1328                 xfs_ilock(ip, XFS_ILOCK_EXCL);
1329                 error = xfs_trans_reserve_quota(tp, mp,
1330                                 ip->i_udquot, ip->i_gdquot, ip->i_pdquot,
1331                                 resblks, 0, XFS_QMOPT_RES_REGBLKS);
1332                 if (error)
1333                         goto error1;
1334 
1335                 xfs_trans_ijoin(tp, ip, 0);
1336 
1337                 /*
1338                  * issue the bunmapi() call to free the blocks
1339                  */
1340                 xfs_bmap_init(&free_list, &firstfsb);
1341                 error = xfs_bunmapi(tp, ip, startoffset_fsb,
1342                                   endoffset_fsb - startoffset_fsb,
1343                                   0, 2, &firstfsb, &free_list, &done);
1344                 if (error)
1345                         goto error0;
1346 
1347                 /*
1348                  * complete the transaction
1349                  */
1350                 error = xfs_bmap_finish(&tp, &free_list, NULL);
1351                 if (error)
1352                         goto error0;
1353 
1354                 error = xfs_trans_commit(tp);
1355                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1356         }
1357 
1358  out:
1359         return error;
1360 
1361  error0:
1362         xfs_bmap_cancel(&free_list);
1363  error1:
1364         xfs_trans_cancel(tp);
1365         xfs_iunlock(ip, XFS_ILOCK_EXCL);
1366         goto out;
1367 }
1368 
1369 /*
1370  * Preallocate and zero a range of a file. This mechanism has the allocation
1371  * semantics of fallocate and in addition converts data in the range to zeroes.
1372  */
1373 int
1374 xfs_zero_file_space(
1375         struct xfs_inode        *ip,
1376         xfs_off_t               offset,
1377         xfs_off_t               len)
1378 {
1379         struct xfs_mount        *mp = ip->i_mount;
1380         uint                    blksize;
1381         int                     error;
1382 
1383         trace_xfs_zero_file_space(ip);
1384 
1385         blksize = 1 << mp->m_sb.sb_blocklog;
1386 
1387         /*
1388          * Punch a hole and prealloc the range. We use hole punch rather than
1389          * unwritten extent conversion for two reasons:
1390          *
1391          * 1.) Hole punch handles partial block zeroing for us.
1392          *
1393          * 2.) If prealloc returns ENOSPC, the file range is still zero-valued
1394          * by virtue of the hole punch.
1395          */
1396         error = xfs_free_file_space(ip, offset, len);
1397         if (error)
1398                 goto out;
1399 
1400         error = xfs_alloc_file_space(ip, round_down(offset, blksize),
1401                                      round_up(offset + len, blksize) -
1402                                      round_down(offset, blksize),
1403                                      XFS_BMAPI_PREALLOC);
1404 out:
1405         return error;
1406 
1407 }
1408 
1409 /*
1410  * @next_fsb will keep track of the extent currently undergoing shift.
1411  * @stop_fsb will keep track of the extent at which we have to stop.
1412  * If we are shifting left, we will start with block (offset + len) and
1413  * shift each extent till last extent.
1414  * If we are shifting right, we will start with last extent inside file space
1415  * and continue until we reach the block corresponding to offset.
1416  */
1417 static int
1418 xfs_shift_file_space(
1419         struct xfs_inode        *ip,
1420         xfs_off_t               offset,
1421         xfs_off_t               len,
1422         enum shift_direction    direction)
1423 {
1424         int                     done = 0;
1425         struct xfs_mount        *mp = ip->i_mount;
1426         struct xfs_trans        *tp;
1427         int                     error;
1428         struct xfs_bmap_free    free_list;
1429         xfs_fsblock_t           first_block;
1430         xfs_fileoff_t           stop_fsb;
1431         xfs_fileoff_t           next_fsb;
1432         xfs_fileoff_t           shift_fsb;
1433 
1434         ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
1435 
1436         if (direction == SHIFT_LEFT) {
1437                 next_fsb = XFS_B_TO_FSB(mp, offset + len);
1438                 stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size);
1439         } else {
1440                 /*
1441                  * If right shift, delegate the work of initialization of
1442                  * next_fsb to xfs_bmap_shift_extent as it has ilock held.
1443                  */
1444                 next_fsb = NULLFSBLOCK;
1445                 stop_fsb = XFS_B_TO_FSB(mp, offset);
1446         }
1447 
1448         shift_fsb = XFS_B_TO_FSB(mp, len);
1449 
1450         /*
1451          * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
1452          * into the accessible region of the file.
1453          */
1454         if (xfs_can_free_eofblocks(ip, true)) {
1455                 error = xfs_free_eofblocks(mp, ip, false);
1456                 if (error)
1457                         return error;
1458         }
1459 
1460         /*
1461          * Writeback and invalidate cache for the remainder of the file as we're
1462          * about to shift down every extent from offset to EOF.
1463          */
1464         error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
1465                                              offset, -1);
1466         if (error)
1467                 return error;
1468         error = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
1469                                         offset >> PAGE_SHIFT, -1);
1470         if (error)
1471                 return error;
1472 
1473         /*
1474          * The extent shiting code works on extent granularity. So, if
1475          * stop_fsb is not the starting block of extent, we need to split
1476          * the extent at stop_fsb.
1477          */
1478         if (direction == SHIFT_RIGHT) {
1479                 error = xfs_bmap_split_extent(ip, stop_fsb);
1480                 if (error)
1481                         return error;
1482         }
1483 
1484         while (!error && !done) {
1485                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
1486                 /*
1487                  * We would need to reserve permanent block for transaction.
1488                  * This will come into picture when after shifting extent into
1489                  * hole we found that adjacent extents can be merged which
1490                  * may lead to freeing of a block during record update.
1491                  */
1492                 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
1493                                 XFS_DIOSTRAT_SPACE_RES(mp, 0), 0);
1494                 if (error) {
1495                         xfs_trans_cancel(tp);
1496                         break;
1497                 }
1498 
1499                 xfs_ilock(ip, XFS_ILOCK_EXCL);
1500                 error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot,
1501                                 ip->i_gdquot, ip->i_pdquot,
1502                                 XFS_DIOSTRAT_SPACE_RES(mp, 0), 0,
1503                                 XFS_QMOPT_RES_REGBLKS);
1504                 if (error)
1505                         goto out_trans_cancel;
1506 
1507                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1508 
1509                 xfs_bmap_init(&free_list, &first_block);
1510 
1511                 /*
1512                  * We are using the write transaction in which max 2 bmbt
1513                  * updates are allowed
1514                  */
1515                 error = xfs_bmap_shift_extents(tp, ip, &next_fsb, shift_fsb,
1516                                 &done, stop_fsb, &first_block, &free_list,
1517                                 direction, XFS_BMAP_MAX_SHIFT_EXTENTS);
1518                 if (error)
1519                         goto out_bmap_cancel;
1520 
1521                 error = xfs_bmap_finish(&tp, &free_list, NULL);
1522                 if (error)
1523                         goto out_bmap_cancel;
1524 
1525                 error = xfs_trans_commit(tp);
1526         }
1527 
1528         return error;
1529 
1530 out_bmap_cancel:
1531         xfs_bmap_cancel(&free_list);
1532 out_trans_cancel:
1533         xfs_trans_cancel(tp);
1534         return error;
1535 }
1536 
1537 /*
1538  * xfs_collapse_file_space()
1539  *      This routine frees disk space and shift extent for the given file.
1540  *      The first thing we do is to free data blocks in the specified range
1541  *      by calling xfs_free_file_space(). It would also sync dirty data
1542  *      and invalidate page cache over the region on which collapse range
1543  *      is working. And Shift extent records to the left to cover a hole.
1544  * RETURNS:
1545  *      0 on success
1546  *      errno on error
1547  *
1548  */
1549 int
1550 xfs_collapse_file_space(
1551         struct xfs_inode        *ip,
1552         xfs_off_t               offset,
1553         xfs_off_t               len)
1554 {
1555         int error;
1556 
1557         ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1558         trace_xfs_collapse_file_space(ip);
1559 
1560         error = xfs_free_file_space(ip, offset, len);
1561         if (error)
1562                 return error;
1563 
1564         return xfs_shift_file_space(ip, offset, len, SHIFT_LEFT);
1565 }
1566 
1567 /*
1568  * xfs_insert_file_space()
1569  *      This routine create hole space by shifting extents for the given file.
1570  *      The first thing we do is to sync dirty data and invalidate page cache
1571  *      over the region on which insert range is working. And split an extent
1572  *      to two extents at given offset by calling xfs_bmap_split_extent.
1573  *      And shift all extent records which are laying between [offset,
1574  *      last allocated extent] to the right to reserve hole range.
1575  * RETURNS:
1576  *      0 on success
1577  *      errno on error
1578  */
1579 int
1580 xfs_insert_file_space(
1581         struct xfs_inode        *ip,
1582         loff_t                  offset,
1583         loff_t                  len)
1584 {
1585         ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1586         trace_xfs_insert_file_space(ip);
1587 
1588         return xfs_shift_file_space(ip, offset, len, SHIFT_RIGHT);
1589 }
1590 
1591 /*
1592  * We need to check that the format of the data fork in the temporary inode is
1593  * valid for the target inode before doing the swap. This is not a problem with
1594  * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
1595  * data fork depending on the space the attribute fork is taking so we can get
1596  * invalid formats on the target inode.
1597  *
1598  * E.g. target has space for 7 extents in extent format, temp inode only has
1599  * space for 6.  If we defragment down to 7 extents, then the tmp format is a
1600  * btree, but when swapped it needs to be in extent format. Hence we can't just
1601  * blindly swap data forks on attr2 filesystems.
1602  *
1603  * Note that we check the swap in both directions so that we don't end up with
1604  * a corrupt temporary inode, either.
1605  *
1606  * Note that fixing the way xfs_fsr sets up the attribute fork in the source
1607  * inode will prevent this situation from occurring, so all we do here is
1608  * reject and log the attempt. basically we are putting the responsibility on
1609  * userspace to get this right.
1610  */
1611 static int
1612 xfs_swap_extents_check_format(
1613         xfs_inode_t     *ip,    /* target inode */
1614         xfs_inode_t     *tip)   /* tmp inode */
1615 {
1616 
1617         /* Should never get a local format */
1618         if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
1619             tip->i_d.di_format == XFS_DINODE_FMT_LOCAL)
1620                 return -EINVAL;
1621 
1622         /*
1623          * if the target inode has less extents that then temporary inode then
1624          * why did userspace call us?
1625          */
1626         if (ip->i_d.di_nextents < tip->i_d.di_nextents)
1627                 return -EINVAL;
1628 
1629         /*
1630          * if the target inode is in extent form and the temp inode is in btree
1631          * form then we will end up with the target inode in the wrong format
1632          * as we already know there are less extents in the temp inode.
1633          */
1634         if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
1635             tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
1636                 return -EINVAL;
1637 
1638         /* Check temp in extent form to max in target */
1639         if (tip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
1640             XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) >
1641                         XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1642                 return -EINVAL;
1643 
1644         /* Check target in extent form to max in temp */
1645         if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
1646             XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) >
1647                         XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1648                 return -EINVAL;
1649 
1650         /*
1651          * If we are in a btree format, check that the temp root block will fit
1652          * in the target and that it has enough extents to be in btree format
1653          * in the target.
1654          *
1655          * Note that we have to be careful to allow btree->extent conversions
1656          * (a common defrag case) which will occur when the temp inode is in
1657          * extent format...
1658          */
1659         if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
1660                 if (XFS_IFORK_BOFF(ip) &&
1661                     XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
1662                         return -EINVAL;
1663                 if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
1664                     XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1665                         return -EINVAL;
1666         }
1667 
1668         /* Reciprocal target->temp btree format checks */
1669         if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
1670                 if (XFS_IFORK_BOFF(tip) &&
1671                     XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
1672                         return -EINVAL;
1673                 if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
1674                     XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1675                         return -EINVAL;
1676         }
1677 
1678         return 0;
1679 }
1680 
1681 static int
1682 xfs_swap_extent_flush(
1683         struct xfs_inode        *ip)
1684 {
1685         int     error;
1686 
1687         error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
1688         if (error)
1689                 return error;
1690         truncate_pagecache_range(VFS_I(ip), 0, -1);
1691 
1692         /* Verify O_DIRECT for ftmp */
1693         if (VFS_I(ip)->i_mapping->nrpages)
1694                 return -EINVAL;
1695         return 0;
1696 }
1697 
1698 int
1699 xfs_swap_extents(
1700         xfs_inode_t     *ip,    /* target inode */
1701         xfs_inode_t     *tip,   /* tmp inode */
1702         xfs_swapext_t   *sxp)
1703 {
1704         xfs_mount_t     *mp = ip->i_mount;
1705         xfs_trans_t     *tp;
1706         xfs_bstat_t     *sbp = &sxp->sx_stat;
1707         xfs_ifork_t     *tempifp, *ifp, *tifp;
1708         int             src_log_flags, target_log_flags;
1709         int             error = 0;
1710         int             aforkblks = 0;
1711         int             taforkblks = 0;
1712         __uint64_t      tmp;
1713         int             lock_flags;
1714 
1715         tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
1716         if (!tempifp) {
1717                 error = -ENOMEM;
1718                 goto out;
1719         }
1720 
1721         /*
1722          * Lock the inodes against other IO, page faults and truncate to
1723          * begin with.  Then we can ensure the inodes are flushed and have no
1724          * page cache safely. Once we have done this we can take the ilocks and
1725          * do the rest of the checks.
1726          */
1727         lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
1728         xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
1729         xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);
1730 
1731         /* Verify that both files have the same format */
1732         if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
1733                 error = -EINVAL;
1734                 goto out_unlock;
1735         }
1736 
1737         /* Verify both files are either real-time or non-realtime */
1738         if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
1739                 error = -EINVAL;
1740                 goto out_unlock;
1741         }
1742 
1743         error = xfs_swap_extent_flush(ip);
1744         if (error)
1745                 goto out_unlock;
1746         error = xfs_swap_extent_flush(tip);
1747         if (error)
1748                 goto out_unlock;
1749 
1750         tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
1751         error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
1752         if (error) {
1753                 xfs_trans_cancel(tp);
1754                 goto out_unlock;
1755         }
1756 
1757         /*
1758          * Lock and join the inodes to the tansaction so that transaction commit
1759          * or cancel will unlock the inodes from this point onwards.
1760          */
1761         xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
1762         lock_flags |= XFS_ILOCK_EXCL;
1763         xfs_trans_ijoin(tp, ip, lock_flags);
1764         xfs_trans_ijoin(tp, tip, lock_flags);
1765 
1766 
1767         /* Verify all data are being swapped */
1768         if (sxp->sx_offset != 0 ||
1769             sxp->sx_length != ip->i_d.di_size ||
1770             sxp->sx_length != tip->i_d.di_size) {
1771                 error = -EFAULT;
1772                 goto out_trans_cancel;
1773         }
1774 
1775         trace_xfs_swap_extent_before(ip, 0);
1776         trace_xfs_swap_extent_before(tip, 1);
1777 
1778         /* check inode formats now that data is flushed */
1779         error = xfs_swap_extents_check_format(ip, tip);
1780         if (error) {
1781                 xfs_notice(mp,
1782                     "%s: inode 0x%llx format is incompatible for exchanging.",
1783                                 __func__, ip->i_ino);
1784                 goto out_trans_cancel;
1785         }
1786 
1787         /*
1788          * Compare the current change & modify times with that
1789          * passed in.  If they differ, we abort this swap.
1790          * This is the mechanism used to ensure the calling
1791          * process that the file was not changed out from
1792          * under it.
1793          */
1794         if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
1795             (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
1796             (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
1797             (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
1798                 error = -EBUSY;
1799                 goto out_trans_cancel;
1800         }
1801         /*
1802          * Count the number of extended attribute blocks
1803          */
1804         if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
1805              (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
1806                 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
1807                 if (error)
1808                         goto out_trans_cancel;
1809         }
1810         if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
1811              (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
1812                 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
1813                         &taforkblks);
1814                 if (error)
1815                         goto out_trans_cancel;
1816         }
1817 
1818         /*
1819          * Before we've swapped the forks, lets set the owners of the forks
1820          * appropriately. We have to do this as we are demand paging the btree
1821          * buffers, and so the validation done on read will expect the owner
1822          * field to be correctly set. Once we change the owners, we can swap the
1823          * inode forks.
1824          *
1825          * Note the trickiness in setting the log flags - we set the owner log
1826          * flag on the opposite inode (i.e. the inode we are setting the new
1827          * owner to be) because once we swap the forks and log that, log
1828          * recovery is going to see the fork as owned by the swapped inode,
1829          * not the pre-swapped inodes.
1830          */
1831         src_log_flags = XFS_ILOG_CORE;
1832         target_log_flags = XFS_ILOG_CORE;
1833         if (ip->i_d.di_version == 3 &&
1834             ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
1835                 target_log_flags |= XFS_ILOG_DOWNER;
1836                 error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK,
1837                                               tip->i_ino, NULL);
1838                 if (error)
1839                         goto out_trans_cancel;
1840         }
1841 
1842         if (tip->i_d.di_version == 3 &&
1843             tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
1844                 src_log_flags |= XFS_ILOG_DOWNER;
1845                 error = xfs_bmbt_change_owner(tp, tip, XFS_DATA_FORK,
1846                                               ip->i_ino, NULL);
1847                 if (error)
1848                         goto out_trans_cancel;
1849         }
1850 
1851         /*
1852          * Swap the data forks of the inodes
1853          */
1854         ifp = &ip->i_df;
1855         tifp = &tip->i_df;
1856         *tempifp = *ifp;        /* struct copy */
1857         *ifp = *tifp;           /* struct copy */
1858         *tifp = *tempifp;       /* struct copy */
1859 
1860         /*
1861          * Fix the on-disk inode values
1862          */
1863         tmp = (__uint64_t)ip->i_d.di_nblocks;
1864         ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
1865         tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
1866 
1867         tmp = (__uint64_t) ip->i_d.di_nextents;
1868         ip->i_d.di_nextents = tip->i_d.di_nextents;
1869         tip->i_d.di_nextents = tmp;
1870 
1871         tmp = (__uint64_t) ip->i_d.di_format;
1872         ip->i_d.di_format = tip->i_d.di_format;
1873         tip->i_d.di_format = tmp;
1874 
1875         /*
1876          * The extents in the source inode could still contain speculative
1877          * preallocation beyond EOF (e.g. the file is open but not modified
1878          * while defrag is in progress). In that case, we need to copy over the
1879          * number of delalloc blocks the data fork in the source inode is
1880          * tracking beyond EOF so that when the fork is truncated away when the
1881          * temporary inode is unlinked we don't underrun the i_delayed_blks
1882          * counter on that inode.
1883          */
1884         ASSERT(tip->i_delayed_blks == 0);
1885         tip->i_delayed_blks = ip->i_delayed_blks;
1886         ip->i_delayed_blks = 0;
1887 
1888         switch (ip->i_d.di_format) {
1889         case XFS_DINODE_FMT_EXTENTS:
1890                 /* If the extents fit in the inode, fix the
1891                  * pointer.  Otherwise it's already NULL or
1892                  * pointing to the extent.
1893                  */
1894                 if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
1895                         ifp->if_u1.if_extents =
1896                                 ifp->if_u2.if_inline_ext;
1897                 }
1898                 src_log_flags |= XFS_ILOG_DEXT;
1899                 break;
1900         case XFS_DINODE_FMT_BTREE:
1901                 ASSERT(ip->i_d.di_version < 3 ||
1902                        (src_log_flags & XFS_ILOG_DOWNER));
1903                 src_log_flags |= XFS_ILOG_DBROOT;
1904                 break;
1905         }
1906 
1907         switch (tip->i_d.di_format) {
1908         case XFS_DINODE_FMT_EXTENTS:
1909                 /* If the extents fit in the inode, fix the
1910                  * pointer.  Otherwise it's already NULL or
1911                  * pointing to the extent.
1912                  */
1913                 if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
1914                         tifp->if_u1.if_extents =
1915                                 tifp->if_u2.if_inline_ext;
1916                 }
1917                 target_log_flags |= XFS_ILOG_DEXT;
1918                 break;
1919         case XFS_DINODE_FMT_BTREE:
1920                 target_log_flags |= XFS_ILOG_DBROOT;
1921                 ASSERT(tip->i_d.di_version < 3 ||
1922                        (target_log_flags & XFS_ILOG_DOWNER));
1923                 break;
1924         }
1925 
1926         xfs_trans_log_inode(tp, ip,  src_log_flags);
1927         xfs_trans_log_inode(tp, tip, target_log_flags);
1928 
1929         /*
1930          * If this is a synchronous mount, make sure that the
1931          * transaction goes to disk before returning to the user.
1932          */
1933         if (mp->m_flags & XFS_MOUNT_WSYNC)
1934                 xfs_trans_set_sync(tp);
1935 
1936         error = xfs_trans_commit(tp);
1937 
1938         trace_xfs_swap_extent_after(ip, 0);
1939         trace_xfs_swap_extent_after(tip, 1);
1940 out:
1941         kmem_free(tempifp);
1942         return error;
1943 
1944 out_unlock:
1945         xfs_iunlock(ip, lock_flags);
1946         xfs_iunlock(tip, lock_flags);
1947         goto out;
1948 
1949 out_trans_cancel:
1950         xfs_trans_cancel(tp);
1951         goto out;
1952 }
1953 

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