d478065b954478c2f61bfe39c2ee9d59e2255d9f
[sfrench/cifs-2.6.git] / fs / xfs / libxfs / xfs_dir2_data.c
1 /*
2  * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3  * Copyright (c) 2013 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_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_mount.h"
25 #include "xfs_da_format.h"
26 #include "xfs_da_btree.h"
27 #include "xfs_inode.h"
28 #include "xfs_dir2.h"
29 #include "xfs_dir2_priv.h"
30 #include "xfs_error.h"
31 #include "xfs_trans.h"
32 #include "xfs_buf_item.h"
33 #include "xfs_cksum.h"
34 #include "xfs_log.h"
35
36 /*
37  * Check the consistency of the data block.
38  * The input can also be a block-format directory.
39  * Return 0 is the buffer is good, otherwise an error.
40  */
41 int
42 __xfs_dir3_data_check(
43         struct xfs_inode        *dp,            /* incore inode pointer */
44         struct xfs_buf          *bp)            /* data block's buffer */
45 {
46         xfs_dir2_dataptr_t      addr;           /* addr for leaf lookup */
47         xfs_dir2_data_free_t    *bf;            /* bestfree table */
48         xfs_dir2_block_tail_t   *btp=NULL;      /* block tail */
49         int                     count;          /* count of entries found */
50         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
51         xfs_dir2_data_entry_t   *dep;           /* data entry */
52         xfs_dir2_data_free_t    *dfp;           /* bestfree entry */
53         xfs_dir2_data_unused_t  *dup;           /* unused entry */
54         char                    *endp;          /* end of useful data */
55         int                     freeseen;       /* mask of bestfrees seen */
56         xfs_dahash_t            hash;           /* hash of current name */
57         int                     i;              /* leaf index */
58         int                     lastfree;       /* last entry was unused */
59         xfs_dir2_leaf_entry_t   *lep=NULL;      /* block leaf entries */
60         xfs_mount_t             *mp;            /* filesystem mount point */
61         char                    *p;             /* current data position */
62         int                     stale;          /* count of stale leaves */
63         struct xfs_name         name;
64         const struct xfs_dir_ops *ops;
65         struct xfs_da_geometry  *geo;
66
67         mp = bp->b_target->bt_mount;
68         geo = mp->m_dir_geo;
69
70         /*
71          * We can be passed a null dp here from a verifier, so we need to go the
72          * hard way to get them.
73          */
74         ops = xfs_dir_get_ops(mp, dp);
75
76         hdr = bp->b_addr;
77         p = (char *)ops->data_entry_p(hdr);
78
79         switch (hdr->magic) {
80         case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
81         case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
82                 btp = xfs_dir2_block_tail_p(geo, hdr);
83                 lep = xfs_dir2_block_leaf_p(btp);
84                 endp = (char *)lep;
85
86                 /*
87                  * The number of leaf entries is limited by the size of the
88                  * block and the amount of space used by the data entries.
89                  * We don't know how much space is used by the data entries yet,
90                  * so just ensure that the count falls somewhere inside the
91                  * block right now.
92                  */
93                 XFS_WANT_CORRUPTED_RETURN(mp, be32_to_cpu(btp->count) <
94                         ((char *)btp - p) / sizeof(struct xfs_dir2_leaf_entry));
95                 break;
96         case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
97         case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
98                 endp = (char *)hdr + geo->blksize;
99                 break;
100         default:
101                 XFS_ERROR_REPORT("Bad Magic", XFS_ERRLEVEL_LOW, mp);
102                 return -EFSCORRUPTED;
103         }
104
105         /*
106          * Account for zero bestfree entries.
107          */
108         bf = ops->data_bestfree_p(hdr);
109         count = lastfree = freeseen = 0;
110         if (!bf[0].length) {
111                 XFS_WANT_CORRUPTED_RETURN(mp, !bf[0].offset);
112                 freeseen |= 1 << 0;
113         }
114         if (!bf[1].length) {
115                 XFS_WANT_CORRUPTED_RETURN(mp, !bf[1].offset);
116                 freeseen |= 1 << 1;
117         }
118         if (!bf[2].length) {
119                 XFS_WANT_CORRUPTED_RETURN(mp, !bf[2].offset);
120                 freeseen |= 1 << 2;
121         }
122
123         XFS_WANT_CORRUPTED_RETURN(mp, be16_to_cpu(bf[0].length) >=
124                                                 be16_to_cpu(bf[1].length));
125         XFS_WANT_CORRUPTED_RETURN(mp, be16_to_cpu(bf[1].length) >=
126                                                 be16_to_cpu(bf[2].length));
127         /*
128          * Loop over the data/unused entries.
129          */
130         while (p < endp) {
131                 dup = (xfs_dir2_data_unused_t *)p;
132                 /*
133                  * If it's unused, look for the space in the bestfree table.
134                  * If we find it, account for that, else make sure it
135                  * doesn't need to be there.
136                  */
137                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
138                         XFS_WANT_CORRUPTED_RETURN(mp, lastfree == 0);
139                         XFS_WANT_CORRUPTED_RETURN(mp,
140                                 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
141                                                (char *)dup - (char *)hdr);
142                         dfp = xfs_dir2_data_freefind(hdr, bf, dup);
143                         if (dfp) {
144                                 i = (int)(dfp - bf);
145                                 XFS_WANT_CORRUPTED_RETURN(mp,
146                                         (freeseen & (1 << i)) == 0);
147                                 freeseen |= 1 << i;
148                         } else {
149                                 XFS_WANT_CORRUPTED_RETURN(mp,
150                                         be16_to_cpu(dup->length) <=
151                                                 be16_to_cpu(bf[2].length));
152                         }
153                         p += be16_to_cpu(dup->length);
154                         lastfree = 1;
155                         continue;
156                 }
157                 /*
158                  * It's a real entry.  Validate the fields.
159                  * If this is a block directory then make sure it's
160                  * in the leaf section of the block.
161                  * The linear search is crude but this is DEBUG code.
162                  */
163                 dep = (xfs_dir2_data_entry_t *)p;
164                 XFS_WANT_CORRUPTED_RETURN(mp, dep->namelen != 0);
165                 XFS_WANT_CORRUPTED_RETURN(mp,
166                         !xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)));
167                 XFS_WANT_CORRUPTED_RETURN(mp,
168                         be16_to_cpu(*ops->data_entry_tag_p(dep)) ==
169                                                (char *)dep - (char *)hdr);
170                 XFS_WANT_CORRUPTED_RETURN(mp,
171                                 ops->data_get_ftype(dep) < XFS_DIR3_FT_MAX);
172                 count++;
173                 lastfree = 0;
174                 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
175                     hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
176                         addr = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
177                                                 (xfs_dir2_data_aoff_t)
178                                                 ((char *)dep - (char *)hdr));
179                         name.name = dep->name;
180                         name.len = dep->namelen;
181                         hash = mp->m_dirnameops->hashname(&name);
182                         for (i = 0; i < be32_to_cpu(btp->count); i++) {
183                                 if (be32_to_cpu(lep[i].address) == addr &&
184                                     be32_to_cpu(lep[i].hashval) == hash)
185                                         break;
186                         }
187                         XFS_WANT_CORRUPTED_RETURN(mp,
188                                                   i < be32_to_cpu(btp->count));
189                 }
190                 p += ops->data_entsize(dep->namelen);
191         }
192         /*
193          * Need to have seen all the entries and all the bestfree slots.
194          */
195         XFS_WANT_CORRUPTED_RETURN(mp, freeseen == 7);
196         if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
197             hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
198                 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
199                         if (lep[i].address ==
200                             cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
201                                 stale++;
202                         if (i > 0)
203                                 XFS_WANT_CORRUPTED_RETURN(mp,
204                                         be32_to_cpu(lep[i].hashval) >=
205                                                 be32_to_cpu(lep[i - 1].hashval));
206                 }
207                 XFS_WANT_CORRUPTED_RETURN(mp, count ==
208                         be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
209                 XFS_WANT_CORRUPTED_RETURN(mp, stale == be32_to_cpu(btp->stale));
210         }
211         return 0;
212 }
213
214 static bool
215 xfs_dir3_data_verify(
216         struct xfs_buf          *bp)
217 {
218         struct xfs_mount        *mp = bp->b_target->bt_mount;
219         struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
220
221         if (xfs_sb_version_hascrc(&mp->m_sb)) {
222                 if (hdr3->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC))
223                         return false;
224                 if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
225                         return false;
226                 if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
227                         return false;
228                 if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
229                         return false;
230         } else {
231                 if (hdr3->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC))
232                         return false;
233         }
234         if (__xfs_dir3_data_check(NULL, bp))
235                 return false;
236         return true;
237 }
238
239 /*
240  * Readahead of the first block of the directory when it is opened is completely
241  * oblivious to the format of the directory. Hence we can either get a block
242  * format buffer or a data format buffer on readahead.
243  */
244 static void
245 xfs_dir3_data_reada_verify(
246         struct xfs_buf          *bp)
247 {
248         struct xfs_dir2_data_hdr *hdr = bp->b_addr;
249
250         switch (hdr->magic) {
251         case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
252         case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
253                 bp->b_ops = &xfs_dir3_block_buf_ops;
254                 bp->b_ops->verify_read(bp);
255                 return;
256         case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
257         case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
258                 bp->b_ops = &xfs_dir3_data_buf_ops;
259                 bp->b_ops->verify_read(bp);
260                 return;
261         default:
262                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
263                 xfs_verifier_error(bp);
264                 break;
265         }
266 }
267
268 static void
269 xfs_dir3_data_read_verify(
270         struct xfs_buf  *bp)
271 {
272         struct xfs_mount        *mp = bp->b_target->bt_mount;
273
274         if (xfs_sb_version_hascrc(&mp->m_sb) &&
275              !xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
276                  xfs_buf_ioerror(bp, -EFSBADCRC);
277         else if (!xfs_dir3_data_verify(bp))
278                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
279
280         if (bp->b_error)
281                 xfs_verifier_error(bp);
282 }
283
284 static void
285 xfs_dir3_data_write_verify(
286         struct xfs_buf  *bp)
287 {
288         struct xfs_mount        *mp = bp->b_target->bt_mount;
289         struct xfs_buf_log_item *bip = bp->b_fspriv;
290         struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
291
292         if (!xfs_dir3_data_verify(bp)) {
293                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
294                 xfs_verifier_error(bp);
295                 return;
296         }
297
298         if (!xfs_sb_version_hascrc(&mp->m_sb))
299                 return;
300
301         if (bip)
302                 hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
303
304         xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
305 }
306
307 const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
308         .name = "xfs_dir3_data",
309         .verify_read = xfs_dir3_data_read_verify,
310         .verify_write = xfs_dir3_data_write_verify,
311 };
312
313 static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
314         .name = "xfs_dir3_data_reada",
315         .verify_read = xfs_dir3_data_reada_verify,
316         .verify_write = xfs_dir3_data_write_verify,
317 };
318
319
320 int
321 xfs_dir3_data_read(
322         struct xfs_trans        *tp,
323         struct xfs_inode        *dp,
324         xfs_dablk_t             bno,
325         xfs_daddr_t             mapped_bno,
326         struct xfs_buf          **bpp)
327 {
328         int                     err;
329
330         err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
331                                 XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
332         if (!err && tp && *bpp)
333                 xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
334         return err;
335 }
336
337 int
338 xfs_dir3_data_readahead(
339         struct xfs_inode        *dp,
340         xfs_dablk_t             bno,
341         xfs_daddr_t             mapped_bno)
342 {
343         return xfs_da_reada_buf(dp, bno, mapped_bno,
344                                 XFS_DATA_FORK, &xfs_dir3_data_reada_buf_ops);
345 }
346
347 /*
348  * Given a data block and an unused entry from that block,
349  * return the bestfree entry if any that corresponds to it.
350  */
351 xfs_dir2_data_free_t *
352 xfs_dir2_data_freefind(
353         struct xfs_dir2_data_hdr *hdr,          /* data block header */
354         struct xfs_dir2_data_free *bf,          /* bestfree table pointer */
355         struct xfs_dir2_data_unused *dup)       /* unused space */
356 {
357         xfs_dir2_data_free_t    *dfp;           /* bestfree entry */
358         xfs_dir2_data_aoff_t    off;            /* offset value needed */
359 #ifdef DEBUG
360         int                     matched;        /* matched the value */
361         int                     seenzero;       /* saw a 0 bestfree entry */
362 #endif
363
364         off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
365
366 #ifdef DEBUG
367         /*
368          * Validate some consistency in the bestfree table.
369          * Check order, non-overlapping entries, and if we find the
370          * one we're looking for it has to be exact.
371          */
372         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
373                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
374                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
375                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
376         for (dfp = &bf[0], seenzero = matched = 0;
377              dfp < &bf[XFS_DIR2_DATA_FD_COUNT];
378              dfp++) {
379                 if (!dfp->offset) {
380                         ASSERT(!dfp->length);
381                         seenzero = 1;
382                         continue;
383                 }
384                 ASSERT(seenzero == 0);
385                 if (be16_to_cpu(dfp->offset) == off) {
386                         matched = 1;
387                         ASSERT(dfp->length == dup->length);
388                 } else if (off < be16_to_cpu(dfp->offset))
389                         ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
390                 else
391                         ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
392                 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
393                 if (dfp > &bf[0])
394                         ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
395         }
396 #endif
397         /*
398          * If this is smaller than the smallest bestfree entry,
399          * it can't be there since they're sorted.
400          */
401         if (be16_to_cpu(dup->length) <
402             be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
403                 return NULL;
404         /*
405          * Look at the three bestfree entries for our guy.
406          */
407         for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
408                 if (!dfp->offset)
409                         return NULL;
410                 if (be16_to_cpu(dfp->offset) == off)
411                         return dfp;
412         }
413         /*
414          * Didn't find it.  This only happens if there are duplicate lengths.
415          */
416         return NULL;
417 }
418
419 /*
420  * Insert an unused-space entry into the bestfree table.
421  */
422 xfs_dir2_data_free_t *                          /* entry inserted */
423 xfs_dir2_data_freeinsert(
424         struct xfs_dir2_data_hdr *hdr,          /* data block pointer */
425         struct xfs_dir2_data_free *dfp,         /* bestfree table pointer */
426         struct xfs_dir2_data_unused *dup,       /* unused space */
427         int                     *loghead)       /* log the data header (out) */
428 {
429         xfs_dir2_data_free_t    new;            /* new bestfree entry */
430
431         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
432                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
433                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
434                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
435
436         new.length = dup->length;
437         new.offset = cpu_to_be16((char *)dup - (char *)hdr);
438
439         /*
440          * Insert at position 0, 1, or 2; or not at all.
441          */
442         if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
443                 dfp[2] = dfp[1];
444                 dfp[1] = dfp[0];
445                 dfp[0] = new;
446                 *loghead = 1;
447                 return &dfp[0];
448         }
449         if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
450                 dfp[2] = dfp[1];
451                 dfp[1] = new;
452                 *loghead = 1;
453                 return &dfp[1];
454         }
455         if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
456                 dfp[2] = new;
457                 *loghead = 1;
458                 return &dfp[2];
459         }
460         return NULL;
461 }
462
463 /*
464  * Remove a bestfree entry from the table.
465  */
466 STATIC void
467 xfs_dir2_data_freeremove(
468         struct xfs_dir2_data_hdr *hdr,          /* data block header */
469         struct xfs_dir2_data_free *bf,          /* bestfree table pointer */
470         struct xfs_dir2_data_free *dfp,         /* bestfree entry pointer */
471         int                     *loghead)       /* out: log data header */
472 {
473
474         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
475                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
476                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
477                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
478
479         /*
480          * It's the first entry, slide the next 2 up.
481          */
482         if (dfp == &bf[0]) {
483                 bf[0] = bf[1];
484                 bf[1] = bf[2];
485         }
486         /*
487          * It's the second entry, slide the 3rd entry up.
488          */
489         else if (dfp == &bf[1])
490                 bf[1] = bf[2];
491         /*
492          * Must be the last entry.
493          */
494         else
495                 ASSERT(dfp == &bf[2]);
496         /*
497          * Clear the 3rd entry, must be zero now.
498          */
499         bf[2].length = 0;
500         bf[2].offset = 0;
501         *loghead = 1;
502 }
503
504 /*
505  * Given a data block, reconstruct its bestfree map.
506  */
507 void
508 xfs_dir2_data_freescan_int(
509         struct xfs_da_geometry  *geo,
510         const struct xfs_dir_ops *ops,
511         struct xfs_dir2_data_hdr *hdr,
512         int                     *loghead)
513 {
514         xfs_dir2_block_tail_t   *btp;           /* block tail */
515         xfs_dir2_data_entry_t   *dep;           /* active data entry */
516         xfs_dir2_data_unused_t  *dup;           /* unused data entry */
517         struct xfs_dir2_data_free *bf;
518         char                    *endp;          /* end of block's data */
519         char                    *p;             /* current entry pointer */
520
521         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
522                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
523                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
524                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
525
526         /*
527          * Start by clearing the table.
528          */
529         bf = ops->data_bestfree_p(hdr);
530         memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
531         *loghead = 1;
532         /*
533          * Set up pointers.
534          */
535         p = (char *)ops->data_entry_p(hdr);
536         if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
537             hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
538                 btp = xfs_dir2_block_tail_p(geo, hdr);
539                 endp = (char *)xfs_dir2_block_leaf_p(btp);
540         } else
541                 endp = (char *)hdr + geo->blksize;
542         /*
543          * Loop over the block's entries.
544          */
545         while (p < endp) {
546                 dup = (xfs_dir2_data_unused_t *)p;
547                 /*
548                  * If it's a free entry, insert it.
549                  */
550                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
551                         ASSERT((char *)dup - (char *)hdr ==
552                                be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
553                         xfs_dir2_data_freeinsert(hdr, bf, dup, loghead);
554                         p += be16_to_cpu(dup->length);
555                 }
556                 /*
557                  * For active entries, check their tags and skip them.
558                  */
559                 else {
560                         dep = (xfs_dir2_data_entry_t *)p;
561                         ASSERT((char *)dep - (char *)hdr ==
562                                be16_to_cpu(*ops->data_entry_tag_p(dep)));
563                         p += ops->data_entsize(dep->namelen);
564                 }
565         }
566 }
567
568 void
569 xfs_dir2_data_freescan(
570         struct xfs_inode        *dp,
571         struct xfs_dir2_data_hdr *hdr,
572         int                     *loghead)
573 {
574         return xfs_dir2_data_freescan_int(dp->i_mount->m_dir_geo, dp->d_ops,
575                         hdr, loghead);
576 }
577
578 /*
579  * Initialize a data block at the given block number in the directory.
580  * Give back the buffer for the created block.
581  */
582 int                                             /* error */
583 xfs_dir3_data_init(
584         xfs_da_args_t           *args,          /* directory operation args */
585         xfs_dir2_db_t           blkno,          /* logical dir block number */
586         struct xfs_buf          **bpp)          /* output block buffer */
587 {
588         struct xfs_buf          *bp;            /* block buffer */
589         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
590         xfs_inode_t             *dp;            /* incore directory inode */
591         xfs_dir2_data_unused_t  *dup;           /* unused entry pointer */
592         struct xfs_dir2_data_free *bf;
593         int                     error;          /* error return value */
594         int                     i;              /* bestfree index */
595         xfs_mount_t             *mp;            /* filesystem mount point */
596         xfs_trans_t             *tp;            /* transaction pointer */
597         int                     t;              /* temp */
598
599         dp = args->dp;
600         mp = dp->i_mount;
601         tp = args->trans;
602         /*
603          * Get the buffer set up for the block.
604          */
605         error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, blkno),
606                                -1, &bp, XFS_DATA_FORK);
607         if (error)
608                 return error;
609         bp->b_ops = &xfs_dir3_data_buf_ops;
610         xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
611
612         /*
613          * Initialize the header.
614          */
615         hdr = bp->b_addr;
616         if (xfs_sb_version_hascrc(&mp->m_sb)) {
617                 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
618
619                 memset(hdr3, 0, sizeof(*hdr3));
620                 hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
621                 hdr3->blkno = cpu_to_be64(bp->b_bn);
622                 hdr3->owner = cpu_to_be64(dp->i_ino);
623                 uuid_copy(&hdr3->uuid, &mp->m_sb.sb_meta_uuid);
624
625         } else
626                 hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
627
628         bf = dp->d_ops->data_bestfree_p(hdr);
629         bf[0].offset = cpu_to_be16(dp->d_ops->data_entry_offset);
630         for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
631                 bf[i].length = 0;
632                 bf[i].offset = 0;
633         }
634
635         /*
636          * Set up an unused entry for the block's body.
637          */
638         dup = dp->d_ops->data_unused_p(hdr);
639         dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
640
641         t = args->geo->blksize - (uint)dp->d_ops->data_entry_offset;
642         bf[0].length = cpu_to_be16(t);
643         dup->length = cpu_to_be16(t);
644         *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
645         /*
646          * Log it and return it.
647          */
648         xfs_dir2_data_log_header(args, bp);
649         xfs_dir2_data_log_unused(args, bp, dup);
650         *bpp = bp;
651         return 0;
652 }
653
654 /*
655  * Log an active data entry from the block.
656  */
657 void
658 xfs_dir2_data_log_entry(
659         struct xfs_da_args      *args,
660         struct xfs_buf          *bp,
661         xfs_dir2_data_entry_t   *dep)           /* data entry pointer */
662 {
663         struct xfs_dir2_data_hdr *hdr = bp->b_addr;
664
665         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
666                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
667                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
668                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
669
670         xfs_trans_log_buf(args->trans, bp, (uint)((char *)dep - (char *)hdr),
671                 (uint)((char *)(args->dp->d_ops->data_entry_tag_p(dep) + 1) -
672                        (char *)hdr - 1));
673 }
674
675 /*
676  * Log a data block header.
677  */
678 void
679 xfs_dir2_data_log_header(
680         struct xfs_da_args      *args,
681         struct xfs_buf          *bp)
682 {
683 #ifdef DEBUG
684         struct xfs_dir2_data_hdr *hdr = bp->b_addr;
685
686         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
687                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
688                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
689                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
690 #endif
691
692         xfs_trans_log_buf(args->trans, bp, 0,
693                           args->dp->d_ops->data_entry_offset - 1);
694 }
695
696 /*
697  * Log a data unused entry.
698  */
699 void
700 xfs_dir2_data_log_unused(
701         struct xfs_da_args      *args,
702         struct xfs_buf          *bp,
703         xfs_dir2_data_unused_t  *dup)           /* data unused pointer */
704 {
705         xfs_dir2_data_hdr_t     *hdr = bp->b_addr;
706
707         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
708                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
709                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
710                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
711
712         /*
713          * Log the first part of the unused entry.
714          */
715         xfs_trans_log_buf(args->trans, bp, (uint)((char *)dup - (char *)hdr),
716                 (uint)((char *)&dup->length + sizeof(dup->length) -
717                        1 - (char *)hdr));
718         /*
719          * Log the end (tag) of the unused entry.
720          */
721         xfs_trans_log_buf(args->trans, bp,
722                 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
723                 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
724                        sizeof(xfs_dir2_data_off_t) - 1));
725 }
726
727 /*
728  * Make a byte range in the data block unused.
729  * Its current contents are unimportant.
730  */
731 void
732 xfs_dir2_data_make_free(
733         struct xfs_da_args      *args,
734         struct xfs_buf          *bp,
735         xfs_dir2_data_aoff_t    offset,         /* starting byte offset */
736         xfs_dir2_data_aoff_t    len,            /* length in bytes */
737         int                     *needlogp,      /* out: log header */
738         int                     *needscanp)     /* out: regen bestfree */
739 {
740         xfs_dir2_data_hdr_t     *hdr;           /* data block pointer */
741         xfs_dir2_data_free_t    *dfp;           /* bestfree pointer */
742         char                    *endptr;        /* end of data area */
743         int                     needscan;       /* need to regen bestfree */
744         xfs_dir2_data_unused_t  *newdup;        /* new unused entry */
745         xfs_dir2_data_unused_t  *postdup;       /* unused entry after us */
746         xfs_dir2_data_unused_t  *prevdup;       /* unused entry before us */
747         struct xfs_dir2_data_free *bf;
748
749         hdr = bp->b_addr;
750
751         /*
752          * Figure out where the end of the data area is.
753          */
754         if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
755             hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC))
756                 endptr = (char *)hdr + args->geo->blksize;
757         else {
758                 xfs_dir2_block_tail_t   *btp;   /* block tail */
759
760                 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
761                         hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
762                 btp = xfs_dir2_block_tail_p(args->geo, hdr);
763                 endptr = (char *)xfs_dir2_block_leaf_p(btp);
764         }
765         /*
766          * If this isn't the start of the block, then back up to
767          * the previous entry and see if it's free.
768          */
769         if (offset > args->dp->d_ops->data_entry_offset) {
770                 __be16                  *tagp;  /* tag just before us */
771
772                 tagp = (__be16 *)((char *)hdr + offset) - 1;
773                 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
774                 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
775                         prevdup = NULL;
776         } else
777                 prevdup = NULL;
778         /*
779          * If this isn't the end of the block, see if the entry after
780          * us is free.
781          */
782         if ((char *)hdr + offset + len < endptr) {
783                 postdup =
784                         (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
785                 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
786                         postdup = NULL;
787         } else
788                 postdup = NULL;
789         ASSERT(*needscanp == 0);
790         needscan = 0;
791         /*
792          * Previous and following entries are both free,
793          * merge everything into a single free entry.
794          */
795         bf = args->dp->d_ops->data_bestfree_p(hdr);
796         if (prevdup && postdup) {
797                 xfs_dir2_data_free_t    *dfp2;  /* another bestfree pointer */
798
799                 /*
800                  * See if prevdup and/or postdup are in bestfree table.
801                  */
802                 dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
803                 dfp2 = xfs_dir2_data_freefind(hdr, bf, postdup);
804                 /*
805                  * We need a rescan unless there are exactly 2 free entries
806                  * namely our two.  Then we know what's happening, otherwise
807                  * since the third bestfree is there, there might be more
808                  * entries.
809                  */
810                 needscan = (bf[2].length != 0);
811                 /*
812                  * Fix up the new big freespace.
813                  */
814                 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
815                 *xfs_dir2_data_unused_tag_p(prevdup) =
816                         cpu_to_be16((char *)prevdup - (char *)hdr);
817                 xfs_dir2_data_log_unused(args, bp, prevdup);
818                 if (!needscan) {
819                         /*
820                          * Has to be the case that entries 0 and 1 are
821                          * dfp and dfp2 (don't know which is which), and
822                          * entry 2 is empty.
823                          * Remove entry 1 first then entry 0.
824                          */
825                         ASSERT(dfp && dfp2);
826                         if (dfp == &bf[1]) {
827                                 dfp = &bf[0];
828                                 ASSERT(dfp2 == dfp);
829                                 dfp2 = &bf[1];
830                         }
831                         xfs_dir2_data_freeremove(hdr, bf, dfp2, needlogp);
832                         xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
833                         /*
834                          * Now insert the new entry.
835                          */
836                         dfp = xfs_dir2_data_freeinsert(hdr, bf, prevdup,
837                                                        needlogp);
838                         ASSERT(dfp == &bf[0]);
839                         ASSERT(dfp->length == prevdup->length);
840                         ASSERT(!dfp[1].length);
841                         ASSERT(!dfp[2].length);
842                 }
843         }
844         /*
845          * The entry before us is free, merge with it.
846          */
847         else if (prevdup) {
848                 dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
849                 be16_add_cpu(&prevdup->length, len);
850                 *xfs_dir2_data_unused_tag_p(prevdup) =
851                         cpu_to_be16((char *)prevdup - (char *)hdr);
852                 xfs_dir2_data_log_unused(args, bp, prevdup);
853                 /*
854                  * If the previous entry was in the table, the new entry
855                  * is longer, so it will be in the table too.  Remove
856                  * the old one and add the new one.
857                  */
858                 if (dfp) {
859                         xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
860                         xfs_dir2_data_freeinsert(hdr, bf, prevdup, needlogp);
861                 }
862                 /*
863                  * Otherwise we need a scan if the new entry is big enough.
864                  */
865                 else {
866                         needscan = be16_to_cpu(prevdup->length) >
867                                    be16_to_cpu(bf[2].length);
868                 }
869         }
870         /*
871          * The following entry is free, merge with it.
872          */
873         else if (postdup) {
874                 dfp = xfs_dir2_data_freefind(hdr, bf, postdup);
875                 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
876                 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
877                 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
878                 *xfs_dir2_data_unused_tag_p(newdup) =
879                         cpu_to_be16((char *)newdup - (char *)hdr);
880                 xfs_dir2_data_log_unused(args, bp, newdup);
881                 /*
882                  * If the following entry was in the table, the new entry
883                  * is longer, so it will be in the table too.  Remove
884                  * the old one and add the new one.
885                  */
886                 if (dfp) {
887                         xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
888                         xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
889                 }
890                 /*
891                  * Otherwise we need a scan if the new entry is big enough.
892                  */
893                 else {
894                         needscan = be16_to_cpu(newdup->length) >
895                                    be16_to_cpu(bf[2].length);
896                 }
897         }
898         /*
899          * Neither neighbor is free.  Make a new entry.
900          */
901         else {
902                 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
903                 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
904                 newdup->length = cpu_to_be16(len);
905                 *xfs_dir2_data_unused_tag_p(newdup) =
906                         cpu_to_be16((char *)newdup - (char *)hdr);
907                 xfs_dir2_data_log_unused(args, bp, newdup);
908                 xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
909         }
910         *needscanp = needscan;
911 }
912
913 /*
914  * Take a byte range out of an existing unused space and make it un-free.
915  */
916 void
917 xfs_dir2_data_use_free(
918         struct xfs_da_args      *args,
919         struct xfs_buf          *bp,
920         xfs_dir2_data_unused_t  *dup,           /* unused entry */
921         xfs_dir2_data_aoff_t    offset,         /* starting offset to use */
922         xfs_dir2_data_aoff_t    len,            /* length to use */
923         int                     *needlogp,      /* out: need to log header */
924         int                     *needscanp)     /* out: need regen bestfree */
925 {
926         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
927         xfs_dir2_data_free_t    *dfp;           /* bestfree pointer */
928         int                     matchback;      /* matches end of freespace */
929         int                     matchfront;     /* matches start of freespace */
930         int                     needscan;       /* need to regen bestfree */
931         xfs_dir2_data_unused_t  *newdup;        /* new unused entry */
932         xfs_dir2_data_unused_t  *newdup2;       /* another new unused entry */
933         int                     oldlen;         /* old unused entry's length */
934         struct xfs_dir2_data_free *bf;
935
936         hdr = bp->b_addr;
937         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
938                hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
939                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
940                hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
941         ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
942         ASSERT(offset >= (char *)dup - (char *)hdr);
943         ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
944         ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
945         /*
946          * Look up the entry in the bestfree table.
947          */
948         oldlen = be16_to_cpu(dup->length);
949         bf = args->dp->d_ops->data_bestfree_p(hdr);
950         dfp = xfs_dir2_data_freefind(hdr, bf, dup);
951         ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
952         /*
953          * Check for alignment with front and back of the entry.
954          */
955         matchfront = (char *)dup - (char *)hdr == offset;
956         matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
957         ASSERT(*needscanp == 0);
958         needscan = 0;
959         /*
960          * If we matched it exactly we just need to get rid of it from
961          * the bestfree table.
962          */
963         if (matchfront && matchback) {
964                 if (dfp) {
965                         needscan = (bf[2].offset != 0);
966                         if (!needscan)
967                                 xfs_dir2_data_freeremove(hdr, bf, dfp,
968                                                          needlogp);
969                 }
970         }
971         /*
972          * We match the first part of the entry.
973          * Make a new entry with the remaining freespace.
974          */
975         else if (matchfront) {
976                 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
977                 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
978                 newdup->length = cpu_to_be16(oldlen - len);
979                 *xfs_dir2_data_unused_tag_p(newdup) =
980                         cpu_to_be16((char *)newdup - (char *)hdr);
981                 xfs_dir2_data_log_unused(args, bp, newdup);
982                 /*
983                  * If it was in the table, remove it and add the new one.
984                  */
985                 if (dfp) {
986                         xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
987                         dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
988                                                        needlogp);
989                         ASSERT(dfp != NULL);
990                         ASSERT(dfp->length == newdup->length);
991                         ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
992                         /*
993                          * If we got inserted at the last slot,
994                          * that means we don't know if there was a better
995                          * choice for the last slot, or not.  Rescan.
996                          */
997                         needscan = dfp == &bf[2];
998                 }
999         }
1000         /*
1001          * We match the last part of the entry.
1002          * Trim the allocated space off the tail of the entry.
1003          */
1004         else if (matchback) {
1005                 newdup = dup;
1006                 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1007                 *xfs_dir2_data_unused_tag_p(newdup) =
1008                         cpu_to_be16((char *)newdup - (char *)hdr);
1009                 xfs_dir2_data_log_unused(args, bp, newdup);
1010                 /*
1011                  * If it was in the table, remove it and add the new one.
1012                  */
1013                 if (dfp) {
1014                         xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
1015                         dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1016                                                        needlogp);
1017                         ASSERT(dfp != NULL);
1018                         ASSERT(dfp->length == newdup->length);
1019                         ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
1020                         /*
1021                          * If we got inserted at the last slot,
1022                          * that means we don't know if there was a better
1023                          * choice for the last slot, or not.  Rescan.
1024                          */
1025                         needscan = dfp == &bf[2];
1026                 }
1027         }
1028         /*
1029          * Poking out the middle of an entry.
1030          * Make two new entries.
1031          */
1032         else {
1033                 newdup = dup;
1034                 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1035                 *xfs_dir2_data_unused_tag_p(newdup) =
1036                         cpu_to_be16((char *)newdup - (char *)hdr);
1037                 xfs_dir2_data_log_unused(args, bp, newdup);
1038                 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1039                 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1040                 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
1041                 *xfs_dir2_data_unused_tag_p(newdup2) =
1042                         cpu_to_be16((char *)newdup2 - (char *)hdr);
1043                 xfs_dir2_data_log_unused(args, bp, newdup2);
1044                 /*
1045                  * If the old entry was in the table, we need to scan
1046                  * if the 3rd entry was valid, since these entries
1047                  * are smaller than the old one.
1048                  * If we don't need to scan that means there were 1 or 2
1049                  * entries in the table, and removing the old and adding
1050                  * the 2 new will work.
1051                  */
1052                 if (dfp) {
1053                         needscan = (bf[2].length != 0);
1054                         if (!needscan) {
1055                                 xfs_dir2_data_freeremove(hdr, bf, dfp,
1056                                                          needlogp);
1057                                 xfs_dir2_data_freeinsert(hdr, bf, newdup,
1058                                                          needlogp);
1059                                 xfs_dir2_data_freeinsert(hdr, bf, newdup2,
1060                                                          needlogp);
1061                         }
1062                 }
1063         }
1064         *needscanp = needscan;
1065 }