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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include "xfs.h"
Nathan Scotta844f452005-11-02 14:38:42 +110019#include "xfs_fs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "xfs_types.h"
Nathan Scotta844f452005-11-02 14:38:42 +110021#include "xfs_bit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "xfs_log.h"
Nathan Scotta844f452005-11-02 14:38:42 +110023#include "xfs_inum.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include "xfs_trans.h"
25#include "xfs_sb.h"
26#include "xfs_ag.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "xfs_mount.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include "xfs_bmap_btree.h"
Nathan Scotta844f452005-11-02 14:38:42 +110029#include "xfs_alloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include "xfs_ialloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include "xfs_dinode.h"
32#include "xfs_inode.h"
Christoph Hellwig38bb7422008-10-30 16:56:22 +110033#include "xfs_inode_item.h"
Nathan Scotta844f452005-11-02 14:38:42 +110034#include "xfs_btree.h"
Christoph Hellwig637aa502008-10-30 16:55:45 +110035#include "xfs_btree_trace.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include "xfs_error.h"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000037#include "xfs_trace.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39/*
40 * Cursor allocation zone.
41 */
42kmem_zone_t *xfs_btree_cur_zone;
43
44/*
45 * Btree magic numbers.
46 */
Christoph Hellwigcdcf43332008-08-13 16:23:50 +100047const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
49};
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110052STATIC int /* error (0 or EFSCORRUPTED) */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110053xfs_btree_check_lblock(
54 struct xfs_btree_cur *cur, /* btree cursor */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110055 struct xfs_btree_block *block, /* btree long form block pointer */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110056 int level, /* level of the btree block */
57 struct xfs_buf *bp) /* buffer for block, if any */
58{
59 int lblock_ok; /* block passes checks */
60 struct xfs_mount *mp; /* file system mount point */
61
62 mp = cur->bc_mp;
63 lblock_ok =
64 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
65 be16_to_cpu(block->bb_level) == level &&
66 be16_to_cpu(block->bb_numrecs) <=
Christoph Hellwigce5e42d2008-10-30 16:55:23 +110067 cur->bc_ops->get_maxrecs(cur, level) &&
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110068 block->bb_u.l.bb_leftsib &&
69 (be64_to_cpu(block->bb_u.l.bb_leftsib) == NULLDFSBNO ||
70 XFS_FSB_SANITY_CHECK(mp,
71 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
72 block->bb_u.l.bb_rightsib &&
73 (be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO ||
74 XFS_FSB_SANITY_CHECK(mp,
75 be64_to_cpu(block->bb_u.l.bb_rightsib)));
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110076 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
77 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
78 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
79 if (bp)
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000080 trace_xfs_btree_corrupt(bp, _RET_IP_);
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110081 XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
82 mp);
83 return XFS_ERROR(EFSCORRUPTED);
84 }
85 return 0;
86}
87
Christoph Hellwig3cc75242008-10-30 16:58:41 +110088STATIC int /* error (0 or EFSCORRUPTED) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070089xfs_btree_check_sblock(
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110090 struct xfs_btree_cur *cur, /* btree cursor */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110091 struct xfs_btree_block *block, /* btree short form block pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 int level, /* level of the btree block */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110093 struct xfs_buf *bp) /* buffer containing block */
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110095 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
96 struct xfs_agf *agf; /* ag. freespace structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 xfs_agblock_t agflen; /* native ag. freespace length */
98 int sblock_ok; /* block passes checks */
99
100 agbp = cur->bc_private.a.agbp;
101 agf = XFS_BUF_TO_AGF(agbp);
Christoph Hellwig16259e72005-11-02 15:11:25 +1100102 agflen = be32_to_cpu(agf->agf_length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 sblock_ok =
Christoph Hellwig16259e72005-11-02 15:11:25 +1100104 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
105 be16_to_cpu(block->bb_level) == level &&
106 be16_to_cpu(block->bb_numrecs) <=
Christoph Hellwigce5e42d2008-10-30 16:55:23 +1100107 cur->bc_ops->get_maxrecs(cur, level) &&
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100108 (be32_to_cpu(block->bb_u.s.bb_leftsib) == NULLAGBLOCK ||
109 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
110 block->bb_u.s.bb_leftsib &&
111 (be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK ||
112 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
113 block->bb_u.s.bb_rightsib;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
115 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
116 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
117 if (bp)
Christoph Hellwig0b1b2132009-12-14 23:14:59 +0000118 trace_xfs_btree_corrupt(bp, _RET_IP_);
Eric Sandeene0c222c2009-07-20 10:52:15 -0500119 XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
120 XFS_ERRLEVEL_LOW, cur->bc_mp, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 return XFS_ERROR(EFSCORRUPTED);
122 }
123 return 0;
124}
125
126/*
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100127 * Debug routine: check that block header is ok.
128 */
129int
130xfs_btree_check_block(
131 struct xfs_btree_cur *cur, /* btree cursor */
132 struct xfs_btree_block *block, /* generic btree block pointer */
133 int level, /* level of the btree block */
134 struct xfs_buf *bp) /* buffer containing block, if any */
135{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100136 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
137 return xfs_btree_check_lblock(cur, block, level, bp);
138 else
139 return xfs_btree_check_sblock(cur, block, level, bp);
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100140}
141
142/*
143 * Check that (long) pointer is ok.
144 */
145int /* error (0 or EFSCORRUPTED) */
146xfs_btree_check_lptr(
147 struct xfs_btree_cur *cur, /* btree cursor */
148 xfs_dfsbno_t bno, /* btree block disk address */
149 int level) /* btree block level */
150{
151 XFS_WANT_CORRUPTED_RETURN(
152 level > 0 &&
153 bno != NULLDFSBNO &&
154 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
155 return 0;
156}
157
Lachlan McIlroy24ee0e42008-10-30 17:05:26 +1100158#ifdef DEBUG
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100159/*
160 * Check that (short) pointer is ok.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100162STATIC int /* error (0 or EFSCORRUPTED) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163xfs_btree_check_sptr(
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100164 struct xfs_btree_cur *cur, /* btree cursor */
165 xfs_agblock_t bno, /* btree block disk address */
166 int level) /* btree block level */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167{
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100168 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 XFS_WANT_CORRUPTED_RETURN(
171 level > 0 &&
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100172 bno != NULLAGBLOCK &&
173 bno != 0 &&
174 bno < agblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 return 0;
176}
177
178/*
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100179 * Check that block ptr is ok.
180 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100181STATIC int /* error (0 or EFSCORRUPTED) */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100182xfs_btree_check_ptr(
183 struct xfs_btree_cur *cur, /* btree cursor */
184 union xfs_btree_ptr *ptr, /* btree block disk address */
185 int index, /* offset from ptr to check */
186 int level) /* btree block level */
187{
188 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
189 return xfs_btree_check_lptr(cur,
190 be64_to_cpu((&ptr->l)[index]), level);
191 } else {
192 return xfs_btree_check_sptr(cur,
193 be32_to_cpu((&ptr->s)[index]), level);
194 }
195}
Lachlan McIlroy24ee0e42008-10-30 17:05:26 +1100196#endif
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100197
198/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 * Delete the btree cursor.
200 */
201void
202xfs_btree_del_cursor(
203 xfs_btree_cur_t *cur, /* btree cursor */
204 int error) /* del because of error */
205{
206 int i; /* btree level */
207
208 /*
209 * Clear the buffer pointers, and release the buffers.
210 * If we're doing this in the face of an error, we
211 * need to make sure to inspect all of the entries
212 * in the bc_bufs array for buffers to be unlocked.
213 * This is because some of the btree code works from
214 * level n down to 0, and if we get an error along
215 * the way we won't have initialized all the entries
216 * down to 0.
217 */
218 for (i = 0; i < cur->bc_nlevels; i++) {
219 if (cur->bc_bufs[i])
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000220 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 else if (!error)
222 break;
223 }
224 /*
225 * Can't free a bmap cursor without having dealt with the
226 * allocated indirect blocks' accounting.
227 */
228 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
229 cur->bc_private.b.allocated == 0);
230 /*
231 * Free the cursor.
232 */
233 kmem_zone_free(xfs_btree_cur_zone, cur);
234}
235
236/*
237 * Duplicate the btree cursor.
238 * Allocate a new one, copy the record, re-get the buffers.
239 */
240int /* error */
241xfs_btree_dup_cursor(
242 xfs_btree_cur_t *cur, /* input cursor */
243 xfs_btree_cur_t **ncur) /* output cursor */
244{
245 xfs_buf_t *bp; /* btree block's buffer pointer */
246 int error; /* error return value */
247 int i; /* level number of btree block */
248 xfs_mount_t *mp; /* mount structure for filesystem */
249 xfs_btree_cur_t *new; /* new cursor value */
250 xfs_trans_t *tp; /* transaction pointer, can be NULL */
251
252 tp = cur->bc_tp;
253 mp = cur->bc_mp;
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 /*
256 * Allocate a new cursor like the old one.
257 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100258 new = cur->bc_ops->dup_cursor(cur);
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 /*
261 * Copy the record currently in the cursor.
262 */
263 new->bc_rec = cur->bc_rec;
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100264
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 /*
266 * For each level current, re-get the buffer and copy the ptr value.
267 */
268 for (i = 0; i < new->bc_nlevels; i++) {
269 new->bc_ptrs[i] = cur->bc_ptrs[i];
270 new->bc_ra[i] = cur->bc_ra[i];
271 if ((bp = cur->bc_bufs[i])) {
272 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
273 XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
274 xfs_btree_del_cursor(new, error);
275 *ncur = NULL;
276 return error;
277 }
278 new->bc_bufs[i] = bp;
279 ASSERT(bp);
280 ASSERT(!XFS_BUF_GETERROR(bp));
281 } else
282 new->bc_bufs[i] = NULL;
283 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 *ncur = new;
285 return 0;
286}
287
288/*
Christoph Hellwig65f1eae2008-10-30 16:55:34 +1100289 * XFS btree block layout and addressing:
290 *
291 * There are two types of blocks in the btree: leaf and non-leaf blocks.
292 *
293 * The leaf record start with a header then followed by records containing
294 * the values. A non-leaf block also starts with the same header, and
295 * then first contains lookup keys followed by an equal number of pointers
296 * to the btree blocks at the previous level.
297 *
298 * +--------+-------+-------+-------+-------+-------+-------+
299 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
300 * +--------+-------+-------+-------+-------+-------+-------+
301 *
302 * +--------+-------+-------+-------+-------+-------+-------+
303 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
304 * +--------+-------+-------+-------+-------+-------+-------+
305 *
306 * The header is called struct xfs_btree_block for reasons better left unknown
307 * and comes in different versions for short (32bit) and long (64bit) block
308 * pointers. The record and key structures are defined by the btree instances
309 * and opaque to the btree core. The block pointers are simple disk endian
310 * integers, available in a short (32bit) and long (64bit) variant.
311 *
312 * The helpers below calculate the offset of a given record, key or pointer
313 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
314 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
315 * inside the btree block is done using indices starting at one, not zero!
316 */
317
318/*
319 * Return size of the btree block header for this btree instance.
320 */
321static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
322{
323 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100324 XFS_BTREE_LBLOCK_LEN :
325 XFS_BTREE_SBLOCK_LEN;
Christoph Hellwig65f1eae2008-10-30 16:55:34 +1100326}
327
328/*
329 * Return size of btree block pointers for this btree instance.
330 */
331static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
332{
333 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
334 sizeof(__be64) : sizeof(__be32);
335}
336
337/*
338 * Calculate offset of the n-th record in a btree block.
339 */
340STATIC size_t
341xfs_btree_rec_offset(
342 struct xfs_btree_cur *cur,
343 int n)
344{
345 return xfs_btree_block_len(cur) +
346 (n - 1) * cur->bc_ops->rec_len;
347}
348
349/*
350 * Calculate offset of the n-th key in a btree block.
351 */
352STATIC size_t
353xfs_btree_key_offset(
354 struct xfs_btree_cur *cur,
355 int n)
356{
357 return xfs_btree_block_len(cur) +
358 (n - 1) * cur->bc_ops->key_len;
359}
360
361/*
362 * Calculate offset of the n-th block pointer in a btree block.
363 */
364STATIC size_t
365xfs_btree_ptr_offset(
366 struct xfs_btree_cur *cur,
367 int n,
368 int level)
369{
370 return xfs_btree_block_len(cur) +
371 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
372 (n - 1) * xfs_btree_ptr_len(cur);
373}
374
375/*
376 * Return a pointer to the n-th record in the btree block.
377 */
378STATIC union xfs_btree_rec *
379xfs_btree_rec_addr(
380 struct xfs_btree_cur *cur,
381 int n,
382 struct xfs_btree_block *block)
383{
384 return (union xfs_btree_rec *)
385 ((char *)block + xfs_btree_rec_offset(cur, n));
386}
387
388/*
389 * Return a pointer to the n-th key in the btree block.
390 */
391STATIC union xfs_btree_key *
392xfs_btree_key_addr(
393 struct xfs_btree_cur *cur,
394 int n,
395 struct xfs_btree_block *block)
396{
397 return (union xfs_btree_key *)
398 ((char *)block + xfs_btree_key_offset(cur, n));
399}
400
401/*
402 * Return a pointer to the n-th block pointer in the btree block.
403 */
404STATIC union xfs_btree_ptr *
405xfs_btree_ptr_addr(
406 struct xfs_btree_cur *cur,
407 int n,
408 struct xfs_btree_block *block)
409{
410 int level = xfs_btree_get_level(block);
411
412 ASSERT(block->bb_level != 0);
413
414 return (union xfs_btree_ptr *)
415 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
416}
417
418/*
Christoph Hellwig8186e512008-10-30 16:54:22 +1100419 * Get a the root block which is stored in the inode.
420 *
421 * For now this btree implementation assumes the btree root is always
422 * stored in the if_broot field of an inode fork.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 */
Christoph Hellwig8186e512008-10-30 16:54:22 +1100424STATIC struct xfs_btree_block *
425xfs_btree_get_iroot(
426 struct xfs_btree_cur *cur)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427{
Christoph Hellwig8186e512008-10-30 16:54:22 +1100428 struct xfs_ifork *ifp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
Christoph Hellwig8186e512008-10-30 16:54:22 +1100430 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
431 return (struct xfs_btree_block *)ifp->if_broot;
432}
433
434/*
435 * Retrieve the block pointer from the cursor at the given level.
436 * This may be an inode btree root or from a buffer.
437 */
438STATIC struct xfs_btree_block * /* generic btree block pointer */
439xfs_btree_get_block(
440 struct xfs_btree_cur *cur, /* btree cursor */
441 int level, /* level in btree */
442 struct xfs_buf **bpp) /* buffer containing the block */
443{
444 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
445 (level == cur->bc_nlevels - 1)) {
446 *bpp = NULL;
447 return xfs_btree_get_iroot(cur);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 }
Christoph Hellwig8186e512008-10-30 16:54:22 +1100449
450 *bpp = cur->bc_bufs[level];
451 return XFS_BUF_TO_BLOCK(*bpp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452}
453
454/*
455 * Get a buffer for the block, return it with no data read.
456 * Long-form addressing.
457 */
458xfs_buf_t * /* buffer for fsbno */
459xfs_btree_get_bufl(
460 xfs_mount_t *mp, /* file system mount point */
461 xfs_trans_t *tp, /* transaction pointer */
462 xfs_fsblock_t fsbno, /* file system block number */
463 uint lock) /* lock flags for get_buf */
464{
465 xfs_buf_t *bp; /* buffer pointer (return value) */
466 xfs_daddr_t d; /* real disk block address */
467
468 ASSERT(fsbno != NULLFSBLOCK);
469 d = XFS_FSB_TO_DADDR(mp, fsbno);
470 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
471 ASSERT(bp);
472 ASSERT(!XFS_BUF_GETERROR(bp));
473 return bp;
474}
475
476/*
477 * Get a buffer for the block, return it with no data read.
478 * Short-form addressing.
479 */
480xfs_buf_t * /* buffer for agno/agbno */
481xfs_btree_get_bufs(
482 xfs_mount_t *mp, /* file system mount point */
483 xfs_trans_t *tp, /* transaction pointer */
484 xfs_agnumber_t agno, /* allocation group number */
485 xfs_agblock_t agbno, /* allocation group block number */
486 uint lock) /* lock flags for get_buf */
487{
488 xfs_buf_t *bp; /* buffer pointer (return value) */
489 xfs_daddr_t d; /* real disk block address */
490
491 ASSERT(agno != NULLAGNUMBER);
492 ASSERT(agbno != NULLAGBLOCK);
493 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
494 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
495 ASSERT(bp);
496 ASSERT(!XFS_BUF_GETERROR(bp));
497 return bp;
498}
499
500/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 * Check for the cursor referring to the last block at the given level.
502 */
503int /* 1=is last block, 0=not last block */
504xfs_btree_islastblock(
505 xfs_btree_cur_t *cur, /* btree cursor */
506 int level) /* level to check */
507{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100508 struct xfs_btree_block *block; /* generic btree block pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 xfs_buf_t *bp; /* buffer containing block */
510
511 block = xfs_btree_get_block(cur, level, &bp);
512 xfs_btree_check_block(cur, block, level, bp);
Christoph Hellwige99ab902008-10-30 16:54:33 +1100513 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
Christoph Hellwig16259e72005-11-02 15:11:25 +1100514 return be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 else
Christoph Hellwig16259e72005-11-02 15:11:25 +1100516 return be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517}
518
519/*
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000520 * Change the cursor to point to the first record at the given level.
521 * Other levels are unaffected.
522 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100523STATIC int /* success=1, failure=0 */
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000524xfs_btree_firstrec(
525 xfs_btree_cur_t *cur, /* btree cursor */
526 int level) /* level to change */
527{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100528 struct xfs_btree_block *block; /* generic btree block pointer */
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000529 xfs_buf_t *bp; /* buffer containing block */
530
531 /*
532 * Get the block pointer for this level.
533 */
534 block = xfs_btree_get_block(cur, level, &bp);
535 xfs_btree_check_block(cur, block, level, bp);
536 /*
537 * It's empty, there is no such record.
538 */
Christoph Hellwigf2277f02008-10-30 16:53:47 +1100539 if (!block->bb_numrecs)
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000540 return 0;
541 /*
542 * Set the ptr value to 1, that's the first record/key.
543 */
544 cur->bc_ptrs[level] = 1;
545 return 1;
546}
547
548/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 * Change the cursor to point to the last record in the current block
550 * at the given level. Other levels are unaffected.
551 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100552STATIC int /* success=1, failure=0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553xfs_btree_lastrec(
554 xfs_btree_cur_t *cur, /* btree cursor */
555 int level) /* level to change */
556{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100557 struct xfs_btree_block *block; /* generic btree block pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 xfs_buf_t *bp; /* buffer containing block */
559
560 /*
561 * Get the block pointer for this level.
562 */
563 block = xfs_btree_get_block(cur, level, &bp);
564 xfs_btree_check_block(cur, block, level, bp);
565 /*
566 * It's empty, there is no such record.
567 */
Christoph Hellwigf2277f02008-10-30 16:53:47 +1100568 if (!block->bb_numrecs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 return 0;
570 /*
571 * Set the ptr value to numrecs, that's the last record/key.
572 */
Christoph Hellwigf2277f02008-10-30 16:53:47 +1100573 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 return 1;
575}
576
577/*
578 * Compute first and last byte offsets for the fields given.
579 * Interprets the offsets table, which contains struct field offsets.
580 */
581void
582xfs_btree_offsets(
583 __int64_t fields, /* bitmask of fields */
584 const short *offsets, /* table of field offsets */
585 int nbits, /* number of bits to inspect */
586 int *first, /* output: first byte offset */
587 int *last) /* output: last byte offset */
588{
589 int i; /* current bit number */
590 __int64_t imask; /* mask for current bit number */
591
592 ASSERT(fields != 0);
593 /*
594 * Find the lowest bit, so the first byte offset.
595 */
596 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
597 if (imask & fields) {
598 *first = offsets[i];
599 break;
600 }
601 }
602 /*
603 * Find the highest bit, so the last byte offset.
604 */
605 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
606 if (imask & fields) {
607 *last = offsets[i + 1] - 1;
608 break;
609 }
610 }
611}
612
613/*
614 * Get a buffer for the block, return it read in.
615 * Long-form addressing.
616 */
617int /* error */
618xfs_btree_read_bufl(
619 xfs_mount_t *mp, /* file system mount point */
620 xfs_trans_t *tp, /* transaction pointer */
621 xfs_fsblock_t fsbno, /* file system block number */
622 uint lock, /* lock flags for read_buf */
623 xfs_buf_t **bpp, /* buffer for fsbno */
624 int refval) /* ref count value for buffer */
625{
626 xfs_buf_t *bp; /* return value */
627 xfs_daddr_t d; /* real disk block address */
628 int error;
629
630 ASSERT(fsbno != NULLFSBLOCK);
631 d = XFS_FSB_TO_DADDR(mp, fsbno);
632 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
633 mp->m_bsize, lock, &bp))) {
634 return error;
635 }
636 ASSERT(!bp || !XFS_BUF_GETERROR(bp));
Dave Chinner821eb212010-12-02 16:31:13 +1100637 if (bp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 *bpp = bp;
640 return 0;
641}
642
643/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 * Read-ahead the block, don't wait for it, don't return a buffer.
645 * Long-form addressing.
646 */
647/* ARGSUSED */
648void
649xfs_btree_reada_bufl(
650 xfs_mount_t *mp, /* file system mount point */
651 xfs_fsblock_t fsbno, /* file system block number */
652 xfs_extlen_t count) /* count of filesystem blocks */
653{
654 xfs_daddr_t d;
655
656 ASSERT(fsbno != NULLFSBLOCK);
657 d = XFS_FSB_TO_DADDR(mp, fsbno);
Christoph Hellwig1a1a3e92010-10-06 18:41:18 +0000658 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
661/*
662 * Read-ahead the block, don't wait for it, don't return a buffer.
663 * Short-form addressing.
664 */
665/* ARGSUSED */
666void
667xfs_btree_reada_bufs(
668 xfs_mount_t *mp, /* file system mount point */
669 xfs_agnumber_t agno, /* allocation group number */
670 xfs_agblock_t agbno, /* allocation group block number */
671 xfs_extlen_t count) /* count of filesystem blocks */
672{
673 xfs_daddr_t d;
674
675 ASSERT(agno != NULLAGNUMBER);
676 ASSERT(agbno != NULLAGBLOCK);
677 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
Christoph Hellwig1a1a3e92010-10-06 18:41:18 +0000678 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679}
680
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100681STATIC int
682xfs_btree_readahead_lblock(
683 struct xfs_btree_cur *cur,
684 int lr,
685 struct xfs_btree_block *block)
686{
687 int rval = 0;
Christoph Hellwige6edbd12009-01-08 13:42:23 -0500688 xfs_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
689 xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100690
691 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
692 xfs_btree_reada_bufl(cur->bc_mp, left, 1);
693 rval++;
694 }
695
696 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
697 xfs_btree_reada_bufl(cur->bc_mp, right, 1);
698 rval++;
699 }
700
701 return rval;
702}
703
704STATIC int
705xfs_btree_readahead_sblock(
706 struct xfs_btree_cur *cur,
707 int lr,
708 struct xfs_btree_block *block)
709{
710 int rval = 0;
711 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
712 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
713
714
715 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
716 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
717 left, 1);
718 rval++;
719 }
720
721 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
722 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
723 right, 1);
724 rval++;
725 }
726
727 return rval;
728}
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730/*
731 * Read-ahead btree blocks, at the given level.
732 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
733 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100734STATIC int
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100735xfs_btree_readahead(
736 struct xfs_btree_cur *cur, /* btree cursor */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 int lev, /* level in btree */
738 int lr) /* left/right bits */
739{
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100740 struct xfs_btree_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100742 /*
743 * No readahead needed if we are at the root level and the
744 * btree root is stored in the inode.
745 */
746 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
747 (lev == cur->bc_nlevels - 1))
748 return 0;
749
750 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
751 return 0;
752
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 cur->bc_ra[lev] |= lr;
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100754 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
755
756 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
757 return xfs_btree_readahead_lblock(cur, lr, block);
758 return xfs_btree_readahead_sblock(cur, lr, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759}
760
761/*
762 * Set the buffer for level "lev" in the cursor to bp, releasing
763 * any previous buffer.
764 */
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000765STATIC void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766xfs_btree_setbuf(
767 xfs_btree_cur_t *cur, /* btree cursor */
768 int lev, /* level in btree */
769 xfs_buf_t *bp) /* new buffer to set */
770{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100771 struct xfs_btree_block *b; /* btree block */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000773 if (cur->bc_bufs[lev])
774 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 cur->bc_bufs[lev] = bp;
776 cur->bc_ra[lev] = 0;
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000777
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 b = XFS_BUF_TO_BLOCK(bp);
Christoph Hellwige99ab902008-10-30 16:54:33 +1100779 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
Christoph Hellwig16259e72005-11-02 15:11:25 +1100780 if (be64_to_cpu(b->bb_u.l.bb_leftsib) == NULLDFSBNO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
Christoph Hellwig16259e72005-11-02 15:11:25 +1100782 if (be64_to_cpu(b->bb_u.l.bb_rightsib) == NULLDFSBNO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
784 } else {
Christoph Hellwig16259e72005-11-02 15:11:25 +1100785 if (be32_to_cpu(b->bb_u.s.bb_leftsib) == NULLAGBLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
Christoph Hellwig16259e72005-11-02 15:11:25 +1100787 if (be32_to_cpu(b->bb_u.s.bb_rightsib) == NULLAGBLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
789 }
790}
Christoph Hellwig637aa502008-10-30 16:55:45 +1100791
792STATIC int
793xfs_btree_ptr_is_null(
794 struct xfs_btree_cur *cur,
795 union xfs_btree_ptr *ptr)
796{
797 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
Dave Chinner33ad9652009-01-21 15:22:17 +1100798 return be64_to_cpu(ptr->l) == NULLDFSBNO;
Christoph Hellwig637aa502008-10-30 16:55:45 +1100799 else
800 return be32_to_cpu(ptr->s) == NULLAGBLOCK;
801}
802
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100803STATIC void
804xfs_btree_set_ptr_null(
805 struct xfs_btree_cur *cur,
806 union xfs_btree_ptr *ptr)
807{
808 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
Dave Chinner33ad9652009-01-21 15:22:17 +1100809 ptr->l = cpu_to_be64(NULLDFSBNO);
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100810 else
811 ptr->s = cpu_to_be32(NULLAGBLOCK);
812}
813
Christoph Hellwig637aa502008-10-30 16:55:45 +1100814/*
815 * Get/set/init sibling pointers
816 */
817STATIC void
818xfs_btree_get_sibling(
819 struct xfs_btree_cur *cur,
820 struct xfs_btree_block *block,
821 union xfs_btree_ptr *ptr,
822 int lr)
823{
824 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
825
826 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
827 if (lr == XFS_BB_RIGHTSIB)
828 ptr->l = block->bb_u.l.bb_rightsib;
829 else
830 ptr->l = block->bb_u.l.bb_leftsib;
831 } else {
832 if (lr == XFS_BB_RIGHTSIB)
833 ptr->s = block->bb_u.s.bb_rightsib;
834 else
835 ptr->s = block->bb_u.s.bb_leftsib;
836 }
837}
838
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100839STATIC void
840xfs_btree_set_sibling(
841 struct xfs_btree_cur *cur,
842 struct xfs_btree_block *block,
843 union xfs_btree_ptr *ptr,
844 int lr)
845{
846 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
847
848 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
849 if (lr == XFS_BB_RIGHTSIB)
850 block->bb_u.l.bb_rightsib = ptr->l;
851 else
852 block->bb_u.l.bb_leftsib = ptr->l;
853 } else {
854 if (lr == XFS_BB_RIGHTSIB)
855 block->bb_u.s.bb_rightsib = ptr->s;
856 else
857 block->bb_u.s.bb_leftsib = ptr->s;
858 }
859}
860
861STATIC void
862xfs_btree_init_block(
863 struct xfs_btree_cur *cur,
864 int level,
865 int numrecs,
866 struct xfs_btree_block *new) /* new block */
867{
868 new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
869 new->bb_level = cpu_to_be16(level);
870 new->bb_numrecs = cpu_to_be16(numrecs);
871
872 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
Dave Chinner33ad9652009-01-21 15:22:17 +1100873 new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
874 new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100875 } else {
876 new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
877 new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
878 }
879}
880
Christoph Hellwig278d0ca2008-10-30 16:56:32 +1100881/*
882 * Return true if ptr is the last record in the btree and
883 * we need to track updateѕ to this record. The decision
884 * will be further refined in the update_lastrec method.
885 */
886STATIC int
887xfs_btree_is_lastrec(
888 struct xfs_btree_cur *cur,
889 struct xfs_btree_block *block,
890 int level)
891{
892 union xfs_btree_ptr ptr;
893
894 if (level > 0)
895 return 0;
896 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
897 return 0;
898
899 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
900 if (!xfs_btree_ptr_is_null(cur, &ptr))
901 return 0;
902 return 1;
903}
904
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100905STATIC void
906xfs_btree_buf_to_ptr(
907 struct xfs_btree_cur *cur,
908 struct xfs_buf *bp,
909 union xfs_btree_ptr *ptr)
910{
911 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
912 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
913 XFS_BUF_ADDR(bp)));
914 else {
Eric Sandeen9d87c312009-01-14 23:22:07 -0600915 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100916 XFS_BUF_ADDR(bp)));
917 }
918}
919
Christoph Hellwig637aa502008-10-30 16:55:45 +1100920STATIC xfs_daddr_t
921xfs_btree_ptr_to_daddr(
922 struct xfs_btree_cur *cur,
923 union xfs_btree_ptr *ptr)
924{
925 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
Dave Chinner33ad9652009-01-21 15:22:17 +1100926 ASSERT(be64_to_cpu(ptr->l) != NULLDFSBNO);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100927
928 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
929 } else {
930 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
931 ASSERT(be32_to_cpu(ptr->s) != NULLAGBLOCK);
932
933 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
934 be32_to_cpu(ptr->s));
935 }
936}
937
938STATIC void
939xfs_btree_set_refs(
940 struct xfs_btree_cur *cur,
941 struct xfs_buf *bp)
942{
943 switch (cur->bc_btnum) {
944 case XFS_BTNUM_BNO:
945 case XFS_BTNUM_CNT:
Dave Chinner821eb212010-12-02 16:31:13 +1100946 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_ALLOC_BTREE_REF);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100947 break;
948 case XFS_BTNUM_INO:
Dave Chinner821eb212010-12-02 16:31:13 +1100949 XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, XFS_INO_BTREE_REF);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100950 break;
951 case XFS_BTNUM_BMAP:
Dave Chinner821eb212010-12-02 16:31:13 +1100952 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_BMAP_BTREE_REF);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100953 break;
954 default:
955 ASSERT(0);
956 }
957}
958
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100959STATIC int
960xfs_btree_get_buf_block(
961 struct xfs_btree_cur *cur,
962 union xfs_btree_ptr *ptr,
963 int flags,
964 struct xfs_btree_block **block,
965 struct xfs_buf **bpp)
966{
967 struct xfs_mount *mp = cur->bc_mp;
968 xfs_daddr_t d;
969
970 /* need to sort out how callers deal with failures first */
Christoph Hellwig0cadda12010-01-19 09:56:44 +0000971 ASSERT(!(flags & XBF_TRYLOCK));
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100972
973 d = xfs_btree_ptr_to_daddr(cur, ptr);
974 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
975 mp->m_bsize, flags);
976
977 ASSERT(*bpp);
978 ASSERT(!XFS_BUF_GETERROR(*bpp));
979
980 *block = XFS_BUF_TO_BLOCK(*bpp);
981 return 0;
982}
983
Christoph Hellwig637aa502008-10-30 16:55:45 +1100984/*
985 * Read in the buffer at the given ptr and return the buffer and
986 * the block pointer within the buffer.
987 */
988STATIC int
989xfs_btree_read_buf_block(
990 struct xfs_btree_cur *cur,
991 union xfs_btree_ptr *ptr,
992 int level,
993 int flags,
994 struct xfs_btree_block **block,
995 struct xfs_buf **bpp)
996{
997 struct xfs_mount *mp = cur->bc_mp;
998 xfs_daddr_t d;
999 int error;
1000
1001 /* need to sort out how callers deal with failures first */
Christoph Hellwig0cadda12010-01-19 09:56:44 +00001002 ASSERT(!(flags & XBF_TRYLOCK));
Christoph Hellwig637aa502008-10-30 16:55:45 +11001003
1004 d = xfs_btree_ptr_to_daddr(cur, ptr);
1005 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1006 mp->m_bsize, flags, bpp);
1007 if (error)
1008 return error;
1009
1010 ASSERT(*bpp != NULL);
1011 ASSERT(!XFS_BUF_GETERROR(*bpp));
1012
1013 xfs_btree_set_refs(cur, *bpp);
1014 *block = XFS_BUF_TO_BLOCK(*bpp);
1015
1016 error = xfs_btree_check_block(cur, *block, level, *bpp);
1017 if (error)
1018 xfs_trans_brelse(cur->bc_tp, *bpp);
1019 return error;
1020}
1021
1022/*
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001023 * Copy keys from one btree block to another.
1024 */
1025STATIC void
1026xfs_btree_copy_keys(
1027 struct xfs_btree_cur *cur,
1028 union xfs_btree_key *dst_key,
1029 union xfs_btree_key *src_key,
1030 int numkeys)
1031{
1032 ASSERT(numkeys >= 0);
1033 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1034}
1035
1036/*
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001037 * Copy records from one btree block to another.
1038 */
1039STATIC void
1040xfs_btree_copy_recs(
1041 struct xfs_btree_cur *cur,
1042 union xfs_btree_rec *dst_rec,
1043 union xfs_btree_rec *src_rec,
1044 int numrecs)
1045{
1046 ASSERT(numrecs >= 0);
1047 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1048}
1049
1050/*
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001051 * Copy block pointers from one btree block to another.
1052 */
1053STATIC void
1054xfs_btree_copy_ptrs(
1055 struct xfs_btree_cur *cur,
1056 union xfs_btree_ptr *dst_ptr,
1057 union xfs_btree_ptr *src_ptr,
1058 int numptrs)
1059{
1060 ASSERT(numptrs >= 0);
1061 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1062}
1063
1064/*
1065 * Shift keys one index left/right inside a single btree block.
1066 */
1067STATIC void
1068xfs_btree_shift_keys(
1069 struct xfs_btree_cur *cur,
1070 union xfs_btree_key *key,
1071 int dir,
1072 int numkeys)
1073{
1074 char *dst_key;
1075
1076 ASSERT(numkeys >= 0);
1077 ASSERT(dir == 1 || dir == -1);
1078
1079 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1080 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1081}
1082
1083/*
1084 * Shift records one index left/right inside a single btree block.
1085 */
1086STATIC void
1087xfs_btree_shift_recs(
1088 struct xfs_btree_cur *cur,
1089 union xfs_btree_rec *rec,
1090 int dir,
1091 int numrecs)
1092{
1093 char *dst_rec;
1094
1095 ASSERT(numrecs >= 0);
1096 ASSERT(dir == 1 || dir == -1);
1097
1098 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1099 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1100}
1101
1102/*
1103 * Shift block pointers one index left/right inside a single btree block.
1104 */
1105STATIC void
1106xfs_btree_shift_ptrs(
1107 struct xfs_btree_cur *cur,
1108 union xfs_btree_ptr *ptr,
1109 int dir,
1110 int numptrs)
1111{
1112 char *dst_ptr;
1113
1114 ASSERT(numptrs >= 0);
1115 ASSERT(dir == 1 || dir == -1);
1116
1117 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1118 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1119}
1120
1121/*
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001122 * Log key values from the btree block.
1123 */
1124STATIC void
1125xfs_btree_log_keys(
1126 struct xfs_btree_cur *cur,
1127 struct xfs_buf *bp,
1128 int first,
1129 int last)
1130{
1131 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1132 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1133
1134 if (bp) {
1135 xfs_trans_log_buf(cur->bc_tp, bp,
1136 xfs_btree_key_offset(cur, first),
1137 xfs_btree_key_offset(cur, last + 1) - 1);
1138 } else {
1139 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1140 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1141 }
1142
1143 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1144}
1145
1146/*
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001147 * Log record values from the btree block.
1148 */
Christoph Hellwigfd6bcc5b2008-10-30 16:58:21 +11001149void
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001150xfs_btree_log_recs(
1151 struct xfs_btree_cur *cur,
1152 struct xfs_buf *bp,
1153 int first,
1154 int last)
1155{
1156 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1157 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1158
1159 xfs_trans_log_buf(cur->bc_tp, bp,
1160 xfs_btree_rec_offset(cur, first),
1161 xfs_btree_rec_offset(cur, last + 1) - 1);
1162
1163 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1164}
1165
1166/*
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001167 * Log block pointer fields from a btree block (nonleaf).
1168 */
1169STATIC void
1170xfs_btree_log_ptrs(
1171 struct xfs_btree_cur *cur, /* btree cursor */
1172 struct xfs_buf *bp, /* buffer containing btree block */
1173 int first, /* index of first pointer to log */
1174 int last) /* index of last pointer to log */
1175{
1176 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1177 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1178
1179 if (bp) {
1180 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1181 int level = xfs_btree_get_level(block);
1182
1183 xfs_trans_log_buf(cur->bc_tp, bp,
1184 xfs_btree_ptr_offset(cur, first, level),
1185 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1186 } else {
1187 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1188 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1189 }
1190
1191 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1192}
1193
1194/*
1195 * Log fields from a btree block header.
1196 */
Christoph Hellwigfd6bcc5b2008-10-30 16:58:21 +11001197void
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001198xfs_btree_log_block(
1199 struct xfs_btree_cur *cur, /* btree cursor */
1200 struct xfs_buf *bp, /* buffer containing btree block */
1201 int fields) /* mask of fields: XFS_BB_... */
1202{
1203 int first; /* first byte offset logged */
1204 int last; /* last byte offset logged */
1205 static const short soffsets[] = { /* table of offsets (short) */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +11001206 offsetof(struct xfs_btree_block, bb_magic),
1207 offsetof(struct xfs_btree_block, bb_level),
1208 offsetof(struct xfs_btree_block, bb_numrecs),
1209 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1210 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1211 XFS_BTREE_SBLOCK_LEN
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001212 };
1213 static const short loffsets[] = { /* table of offsets (long) */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +11001214 offsetof(struct xfs_btree_block, bb_magic),
1215 offsetof(struct xfs_btree_block, bb_level),
1216 offsetof(struct xfs_btree_block, bb_numrecs),
1217 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1218 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1219 XFS_BTREE_LBLOCK_LEN
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001220 };
1221
1222 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1223 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1224
1225 if (bp) {
1226 xfs_btree_offsets(fields,
1227 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1228 loffsets : soffsets,
1229 XFS_BB_NUM_BITS, &first, &last);
1230 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1231 } else {
1232 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1233 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1234 }
1235
1236 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1237}
1238
1239/*
Christoph Hellwig637aa502008-10-30 16:55:45 +11001240 * Increment cursor by one record at the level.
1241 * For nonzero levels the leaf-ward information is untouched.
1242 */
1243int /* error */
1244xfs_btree_increment(
1245 struct xfs_btree_cur *cur,
1246 int level,
1247 int *stat) /* success/failure */
1248{
1249 struct xfs_btree_block *block;
1250 union xfs_btree_ptr ptr;
1251 struct xfs_buf *bp;
1252 int error; /* error return value */
1253 int lev;
1254
1255 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1256 XFS_BTREE_TRACE_ARGI(cur, level);
1257
1258 ASSERT(level < cur->bc_nlevels);
1259
1260 /* Read-ahead to the right at this level. */
1261 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1262
1263 /* Get a pointer to the btree block. */
1264 block = xfs_btree_get_block(cur, level, &bp);
1265
1266#ifdef DEBUG
1267 error = xfs_btree_check_block(cur, block, level, bp);
1268 if (error)
1269 goto error0;
1270#endif
1271
1272 /* We're done if we remain in the block after the increment. */
1273 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1274 goto out1;
1275
1276 /* Fail if we just went off the right edge of the tree. */
1277 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1278 if (xfs_btree_ptr_is_null(cur, &ptr))
1279 goto out0;
1280
1281 XFS_BTREE_STATS_INC(cur, increment);
1282
1283 /*
1284 * March up the tree incrementing pointers.
1285 * Stop when we don't go off the right edge of a block.
1286 */
1287 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1288 block = xfs_btree_get_block(cur, lev, &bp);
1289
1290#ifdef DEBUG
1291 error = xfs_btree_check_block(cur, block, lev, bp);
1292 if (error)
1293 goto error0;
1294#endif
1295
1296 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1297 break;
1298
1299 /* Read-ahead the right block for the next loop. */
1300 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1301 }
1302
1303 /*
1304 * If we went off the root then we are either seriously
1305 * confused or have the tree root in an inode.
1306 */
1307 if (lev == cur->bc_nlevels) {
1308 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1309 goto out0;
1310 ASSERT(0);
1311 error = EFSCORRUPTED;
1312 goto error0;
1313 }
1314 ASSERT(lev < cur->bc_nlevels);
1315
1316 /*
1317 * Now walk back down the tree, fixing up the cursor's buffer
1318 * pointers and key numbers.
1319 */
1320 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1321 union xfs_btree_ptr *ptrp;
1322
1323 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1324 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1325 0, &block, &bp);
1326 if (error)
1327 goto error0;
1328
1329 xfs_btree_setbuf(cur, lev, bp);
1330 cur->bc_ptrs[lev] = 1;
1331 }
1332out1:
1333 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1334 *stat = 1;
1335 return 0;
1336
1337out0:
1338 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1339 *stat = 0;
1340 return 0;
1341
1342error0:
1343 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1344 return error;
1345}
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001346
1347/*
1348 * Decrement cursor by one record at the level.
1349 * For nonzero levels the leaf-ward information is untouched.
1350 */
1351int /* error */
1352xfs_btree_decrement(
1353 struct xfs_btree_cur *cur,
1354 int level,
1355 int *stat) /* success/failure */
1356{
1357 struct xfs_btree_block *block;
1358 xfs_buf_t *bp;
1359 int error; /* error return value */
1360 int lev;
1361 union xfs_btree_ptr ptr;
1362
1363 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1364 XFS_BTREE_TRACE_ARGI(cur, level);
1365
1366 ASSERT(level < cur->bc_nlevels);
1367
1368 /* Read-ahead to the left at this level. */
1369 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1370
1371 /* We're done if we remain in the block after the decrement. */
1372 if (--cur->bc_ptrs[level] > 0)
1373 goto out1;
1374
1375 /* Get a pointer to the btree block. */
1376 block = xfs_btree_get_block(cur, level, &bp);
1377
1378#ifdef DEBUG
1379 error = xfs_btree_check_block(cur, block, level, bp);
1380 if (error)
1381 goto error0;
1382#endif
1383
1384 /* Fail if we just went off the left edge of the tree. */
1385 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1386 if (xfs_btree_ptr_is_null(cur, &ptr))
1387 goto out0;
1388
1389 XFS_BTREE_STATS_INC(cur, decrement);
1390
1391 /*
1392 * March up the tree decrementing pointers.
1393 * Stop when we don't go off the left edge of a block.
1394 */
1395 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1396 if (--cur->bc_ptrs[lev] > 0)
1397 break;
1398 /* Read-ahead the left block for the next loop. */
1399 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1400 }
1401
1402 /*
1403 * If we went off the root then we are seriously confused.
1404 * or the root of the tree is in an inode.
1405 */
1406 if (lev == cur->bc_nlevels) {
1407 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1408 goto out0;
1409 ASSERT(0);
1410 error = EFSCORRUPTED;
1411 goto error0;
1412 }
1413 ASSERT(lev < cur->bc_nlevels);
1414
1415 /*
1416 * Now walk back down the tree, fixing up the cursor's buffer
1417 * pointers and key numbers.
1418 */
1419 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1420 union xfs_btree_ptr *ptrp;
1421
1422 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1423 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1424 0, &block, &bp);
1425 if (error)
1426 goto error0;
1427 xfs_btree_setbuf(cur, lev, bp);
1428 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1429 }
1430out1:
1431 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1432 *stat = 1;
1433 return 0;
1434
1435out0:
1436 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1437 *stat = 0;
1438 return 0;
1439
1440error0:
1441 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1442 return error;
1443}
1444
Christoph Hellwigfe033cc2008-10-30 16:56:09 +11001445STATIC int
1446xfs_btree_lookup_get_block(
1447 struct xfs_btree_cur *cur, /* btree cursor */
1448 int level, /* level in the btree */
1449 union xfs_btree_ptr *pp, /* ptr to btree block */
1450 struct xfs_btree_block **blkp) /* return btree block */
1451{
1452 struct xfs_buf *bp; /* buffer pointer for btree block */
1453 int error = 0;
1454
1455 /* special case the root block if in an inode */
1456 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1457 (level == cur->bc_nlevels - 1)) {
1458 *blkp = xfs_btree_get_iroot(cur);
1459 return 0;
1460 }
1461
1462 /*
1463 * If the old buffer at this level for the disk address we are
1464 * looking for re-use it.
1465 *
1466 * Otherwise throw it away and get a new one.
1467 */
1468 bp = cur->bc_bufs[level];
1469 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1470 *blkp = XFS_BUF_TO_BLOCK(bp);
1471 return 0;
1472 }
1473
1474 error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1475 if (error)
1476 return error;
1477
1478 xfs_btree_setbuf(cur, level, bp);
1479 return 0;
1480}
1481
1482/*
1483 * Get current search key. For level 0 we don't actually have a key
1484 * structure so we make one up from the record. For all other levels
1485 * we just return the right key.
1486 */
1487STATIC union xfs_btree_key *
1488xfs_lookup_get_search_key(
1489 struct xfs_btree_cur *cur,
1490 int level,
1491 int keyno,
1492 struct xfs_btree_block *block,
1493 union xfs_btree_key *kp)
1494{
1495 if (level == 0) {
1496 cur->bc_ops->init_key_from_rec(kp,
1497 xfs_btree_rec_addr(cur, keyno, block));
1498 return kp;
1499 }
1500
1501 return xfs_btree_key_addr(cur, keyno, block);
1502}
1503
1504/*
1505 * Lookup the record. The cursor is made to point to it, based on dir.
1506 * Return 0 if can't find any such record, 1 for success.
1507 */
1508int /* error */
1509xfs_btree_lookup(
1510 struct xfs_btree_cur *cur, /* btree cursor */
1511 xfs_lookup_t dir, /* <=, ==, or >= */
1512 int *stat) /* success/failure */
1513{
1514 struct xfs_btree_block *block; /* current btree block */
1515 __int64_t diff; /* difference for the current key */
1516 int error; /* error return value */
1517 int keyno; /* current key number */
1518 int level; /* level in the btree */
1519 union xfs_btree_ptr *pp; /* ptr to btree block */
1520 union xfs_btree_ptr ptr; /* ptr to btree block */
1521
1522 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1523 XFS_BTREE_TRACE_ARGI(cur, dir);
1524
1525 XFS_BTREE_STATS_INC(cur, lookup);
1526
1527 block = NULL;
1528 keyno = 0;
1529
1530 /* initialise start pointer from cursor */
1531 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1532 pp = &ptr;
1533
1534 /*
1535 * Iterate over each level in the btree, starting at the root.
1536 * For each level above the leaves, find the key we need, based
1537 * on the lookup record, then follow the corresponding block
1538 * pointer down to the next level.
1539 */
1540 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1541 /* Get the block we need to do the lookup on. */
1542 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1543 if (error)
1544 goto error0;
1545
1546 if (diff == 0) {
1547 /*
1548 * If we already had a key match at a higher level, we
1549 * know we need to use the first entry in this block.
1550 */
1551 keyno = 1;
1552 } else {
1553 /* Otherwise search this block. Do a binary search. */
1554
1555 int high; /* high entry number */
1556 int low; /* low entry number */
1557
1558 /* Set low and high entry numbers, 1-based. */
1559 low = 1;
1560 high = xfs_btree_get_numrecs(block);
1561 if (!high) {
1562 /* Block is empty, must be an empty leaf. */
1563 ASSERT(level == 0 && cur->bc_nlevels == 1);
1564
1565 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1566 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1567 *stat = 0;
1568 return 0;
1569 }
1570
1571 /* Binary search the block. */
1572 while (low <= high) {
1573 union xfs_btree_key key;
1574 union xfs_btree_key *kp;
1575
1576 XFS_BTREE_STATS_INC(cur, compare);
1577
1578 /* keyno is average of low and high. */
1579 keyno = (low + high) >> 1;
1580
1581 /* Get current search key */
1582 kp = xfs_lookup_get_search_key(cur, level,
1583 keyno, block, &key);
1584
1585 /*
1586 * Compute difference to get next direction:
1587 * - less than, move right
1588 * - greater than, move left
1589 * - equal, we're done
1590 */
1591 diff = cur->bc_ops->key_diff(cur, kp);
1592 if (diff < 0)
1593 low = keyno + 1;
1594 else if (diff > 0)
1595 high = keyno - 1;
1596 else
1597 break;
1598 }
1599 }
1600
1601 /*
1602 * If there are more levels, set up for the next level
1603 * by getting the block number and filling in the cursor.
1604 */
1605 if (level > 0) {
1606 /*
1607 * If we moved left, need the previous key number,
1608 * unless there isn't one.
1609 */
1610 if (diff > 0 && --keyno < 1)
1611 keyno = 1;
1612 pp = xfs_btree_ptr_addr(cur, keyno, block);
1613
1614#ifdef DEBUG
1615 error = xfs_btree_check_ptr(cur, pp, 0, level);
1616 if (error)
1617 goto error0;
1618#endif
1619 cur->bc_ptrs[level] = keyno;
1620 }
1621 }
1622
1623 /* Done with the search. See if we need to adjust the results. */
1624 if (dir != XFS_LOOKUP_LE && diff < 0) {
1625 keyno++;
1626 /*
1627 * If ge search and we went off the end of the block, but it's
1628 * not the last block, we're in the wrong block.
1629 */
1630 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1631 if (dir == XFS_LOOKUP_GE &&
1632 keyno > xfs_btree_get_numrecs(block) &&
1633 !xfs_btree_ptr_is_null(cur, &ptr)) {
1634 int i;
1635
1636 cur->bc_ptrs[0] = keyno;
1637 error = xfs_btree_increment(cur, 0, &i);
1638 if (error)
1639 goto error0;
1640 XFS_WANT_CORRUPTED_RETURN(i == 1);
1641 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1642 *stat = 1;
1643 return 0;
1644 }
1645 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1646 keyno--;
1647 cur->bc_ptrs[0] = keyno;
1648
1649 /* Return if we succeeded or not. */
1650 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1651 *stat = 0;
1652 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1653 *stat = 1;
1654 else
1655 *stat = 0;
1656 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1657 return 0;
1658
1659error0:
1660 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1661 return error;
1662}
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001663
1664/*
1665 * Update keys at all levels from here to the root along the cursor's path.
1666 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11001667STATIC int
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001668xfs_btree_updkey(
1669 struct xfs_btree_cur *cur,
1670 union xfs_btree_key *keyp,
1671 int level)
1672{
1673 struct xfs_btree_block *block;
1674 struct xfs_buf *bp;
1675 union xfs_btree_key *kp;
1676 int ptr;
1677
1678 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1679 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1680
1681 ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1682
1683 /*
1684 * Go up the tree from this level toward the root.
1685 * At each level, update the key value to the value input.
1686 * Stop when we reach a level where the cursor isn't pointing
1687 * at the first entry in the block.
1688 */
1689 for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1690#ifdef DEBUG
1691 int error;
1692#endif
1693 block = xfs_btree_get_block(cur, level, &bp);
1694#ifdef DEBUG
1695 error = xfs_btree_check_block(cur, block, level, bp);
1696 if (error) {
1697 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1698 return error;
1699 }
1700#endif
1701 ptr = cur->bc_ptrs[level];
1702 kp = xfs_btree_key_addr(cur, ptr, block);
1703 xfs_btree_copy_keys(cur, kp, keyp, 1);
1704 xfs_btree_log_keys(cur, bp, ptr, ptr);
1705 }
1706
1707 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1708 return 0;
1709}
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001710
1711/*
1712 * Update the record referred to by cur to the value in the
1713 * given record. This either works (return 0) or gets an
1714 * EFSCORRUPTED error.
1715 */
1716int
1717xfs_btree_update(
1718 struct xfs_btree_cur *cur,
1719 union xfs_btree_rec *rec)
1720{
1721 struct xfs_btree_block *block;
1722 struct xfs_buf *bp;
1723 int error;
1724 int ptr;
1725 union xfs_btree_rec *rp;
1726
1727 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1728 XFS_BTREE_TRACE_ARGR(cur, rec);
1729
1730 /* Pick up the current block. */
1731 block = xfs_btree_get_block(cur, 0, &bp);
1732
1733#ifdef DEBUG
1734 error = xfs_btree_check_block(cur, block, 0, bp);
1735 if (error)
1736 goto error0;
1737#endif
1738 /* Get the address of the rec to be updated. */
1739 ptr = cur->bc_ptrs[0];
1740 rp = xfs_btree_rec_addr(cur, ptr, block);
1741
1742 /* Fill in the new contents and log them. */
1743 xfs_btree_copy_recs(cur, rp, rec, 1);
1744 xfs_btree_log_recs(cur, bp, ptr, ptr);
1745
1746 /*
1747 * If we are tracking the last record in the tree and
1748 * we are at the far right edge of the tree, update it.
1749 */
1750 if (xfs_btree_is_lastrec(cur, block, 0)) {
1751 cur->bc_ops->update_lastrec(cur, block, rec,
1752 ptr, LASTREC_UPDATE);
1753 }
1754
1755 /* Updating first rec in leaf. Pass new key value up to our parent. */
1756 if (ptr == 1) {
1757 union xfs_btree_key key;
1758
1759 cur->bc_ops->init_key_from_rec(&key, rec);
1760 error = xfs_btree_updkey(cur, &key, 1);
1761 if (error)
1762 goto error0;
1763 }
1764
1765 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1766 return 0;
1767
1768error0:
1769 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1770 return error;
1771}
1772
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001773/*
Christoph Hellwig687b8902008-10-30 16:56:53 +11001774 * Move 1 record left from cur/level if possible.
1775 * Update cur to reflect the new path.
1776 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11001777STATIC int /* error */
Christoph Hellwig687b8902008-10-30 16:56:53 +11001778xfs_btree_lshift(
1779 struct xfs_btree_cur *cur,
1780 int level,
1781 int *stat) /* success/failure */
1782{
1783 union xfs_btree_key key; /* btree key */
1784 struct xfs_buf *lbp; /* left buffer pointer */
1785 struct xfs_btree_block *left; /* left btree block */
1786 int lrecs; /* left record count */
1787 struct xfs_buf *rbp; /* right buffer pointer */
1788 struct xfs_btree_block *right; /* right btree block */
1789 int rrecs; /* right record count */
1790 union xfs_btree_ptr lptr; /* left btree pointer */
1791 union xfs_btree_key *rkp = NULL; /* right btree key */
1792 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
1793 union xfs_btree_rec *rrp = NULL; /* right record pointer */
1794 int error; /* error return value */
1795
1796 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1797 XFS_BTREE_TRACE_ARGI(cur, level);
1798
1799 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1800 level == cur->bc_nlevels - 1)
1801 goto out0;
1802
1803 /* Set up variables for this block as "right". */
1804 right = xfs_btree_get_block(cur, level, &rbp);
1805
1806#ifdef DEBUG
1807 error = xfs_btree_check_block(cur, right, level, rbp);
1808 if (error)
1809 goto error0;
1810#endif
1811
1812 /* If we've got no left sibling then we can't shift an entry left. */
1813 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1814 if (xfs_btree_ptr_is_null(cur, &lptr))
1815 goto out0;
1816
1817 /*
1818 * If the cursor entry is the one that would be moved, don't
1819 * do it... it's too complicated.
1820 */
1821 if (cur->bc_ptrs[level] <= 1)
1822 goto out0;
1823
1824 /* Set up the left neighbor as "left". */
1825 error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
1826 if (error)
1827 goto error0;
1828
1829 /* If it's full, it can't take another entry. */
1830 lrecs = xfs_btree_get_numrecs(left);
1831 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
1832 goto out0;
1833
1834 rrecs = xfs_btree_get_numrecs(right);
1835
1836 /*
1837 * We add one entry to the left side and remove one for the right side.
Malcolm Parsons9da096f2009-03-29 09:55:42 +02001838 * Account for it here, the changes will be updated on disk and logged
Christoph Hellwig687b8902008-10-30 16:56:53 +11001839 * later.
1840 */
1841 lrecs++;
1842 rrecs--;
1843
1844 XFS_BTREE_STATS_INC(cur, lshift);
1845 XFS_BTREE_STATS_ADD(cur, moves, 1);
1846
1847 /*
1848 * If non-leaf, copy a key and a ptr to the left block.
1849 * Log the changes to the left block.
1850 */
1851 if (level > 0) {
1852 /* It's a non-leaf. Move keys and pointers. */
1853 union xfs_btree_key *lkp; /* left btree key */
1854 union xfs_btree_ptr *lpp; /* left address pointer */
1855
1856 lkp = xfs_btree_key_addr(cur, lrecs, left);
1857 rkp = xfs_btree_key_addr(cur, 1, right);
1858
1859 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
1860 rpp = xfs_btree_ptr_addr(cur, 1, right);
1861#ifdef DEBUG
1862 error = xfs_btree_check_ptr(cur, rpp, 0, level);
1863 if (error)
1864 goto error0;
1865#endif
1866 xfs_btree_copy_keys(cur, lkp, rkp, 1);
1867 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
1868
1869 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
1870 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
1871
Christoph Hellwig4a26e662008-10-30 16:58:32 +11001872 ASSERT(cur->bc_ops->keys_inorder(cur,
1873 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
Christoph Hellwig687b8902008-10-30 16:56:53 +11001874 } else {
1875 /* It's a leaf. Move records. */
1876 union xfs_btree_rec *lrp; /* left record pointer */
1877
1878 lrp = xfs_btree_rec_addr(cur, lrecs, left);
1879 rrp = xfs_btree_rec_addr(cur, 1, right);
1880
1881 xfs_btree_copy_recs(cur, lrp, rrp, 1);
1882 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
1883
Christoph Hellwig4a26e662008-10-30 16:58:32 +11001884 ASSERT(cur->bc_ops->recs_inorder(cur,
1885 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
Christoph Hellwig687b8902008-10-30 16:56:53 +11001886 }
1887
1888 xfs_btree_set_numrecs(left, lrecs);
1889 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
1890
1891 xfs_btree_set_numrecs(right, rrecs);
1892 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
1893
1894 /*
1895 * Slide the contents of right down one entry.
1896 */
1897 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
1898 if (level > 0) {
1899 /* It's a nonleaf. operate on keys and ptrs */
1900#ifdef DEBUG
1901 int i; /* loop index */
1902
1903 for (i = 0; i < rrecs; i++) {
1904 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
1905 if (error)
1906 goto error0;
1907 }
1908#endif
1909 xfs_btree_shift_keys(cur,
1910 xfs_btree_key_addr(cur, 2, right),
1911 -1, rrecs);
1912 xfs_btree_shift_ptrs(cur,
1913 xfs_btree_ptr_addr(cur, 2, right),
1914 -1, rrecs);
1915
1916 xfs_btree_log_keys(cur, rbp, 1, rrecs);
1917 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
1918 } else {
1919 /* It's a leaf. operate on records */
1920 xfs_btree_shift_recs(cur,
1921 xfs_btree_rec_addr(cur, 2, right),
1922 -1, rrecs);
1923 xfs_btree_log_recs(cur, rbp, 1, rrecs);
1924
1925 /*
1926 * If it's the first record in the block, we'll need a key
1927 * structure to pass up to the next level (updkey).
1928 */
1929 cur->bc_ops->init_key_from_rec(&key,
1930 xfs_btree_rec_addr(cur, 1, right));
1931 rkp = &key;
1932 }
1933
1934 /* Update the parent key values of right. */
1935 error = xfs_btree_updkey(cur, rkp, level + 1);
1936 if (error)
1937 goto error0;
1938
1939 /* Slide the cursor value left one. */
1940 cur->bc_ptrs[level]--;
1941
1942 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1943 *stat = 1;
1944 return 0;
1945
1946out0:
1947 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1948 *stat = 0;
1949 return 0;
1950
1951error0:
1952 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1953 return error;
1954}
1955
1956/*
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001957 * Move 1 record right from cur/level if possible.
1958 * Update cur to reflect the new path.
1959 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11001960STATIC int /* error */
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001961xfs_btree_rshift(
1962 struct xfs_btree_cur *cur,
1963 int level,
1964 int *stat) /* success/failure */
1965{
1966 union xfs_btree_key key; /* btree key */
1967 struct xfs_buf *lbp; /* left buffer pointer */
1968 struct xfs_btree_block *left; /* left btree block */
1969 struct xfs_buf *rbp; /* right buffer pointer */
1970 struct xfs_btree_block *right; /* right btree block */
1971 struct xfs_btree_cur *tcur; /* temporary btree cursor */
1972 union xfs_btree_ptr rptr; /* right block pointer */
1973 union xfs_btree_key *rkp; /* right btree key */
1974 int rrecs; /* right record count */
1975 int lrecs; /* left record count */
1976 int error; /* error return value */
1977 int i; /* loop counter */
1978
1979 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1980 XFS_BTREE_TRACE_ARGI(cur, level);
1981
1982 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1983 (level == cur->bc_nlevels - 1))
1984 goto out0;
1985
1986 /* Set up variables for this block as "left". */
1987 left = xfs_btree_get_block(cur, level, &lbp);
1988
1989#ifdef DEBUG
1990 error = xfs_btree_check_block(cur, left, level, lbp);
1991 if (error)
1992 goto error0;
1993#endif
1994
1995 /* If we've got no right sibling then we can't shift an entry right. */
1996 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
1997 if (xfs_btree_ptr_is_null(cur, &rptr))
1998 goto out0;
1999
2000 /*
2001 * If the cursor entry is the one that would be moved, don't
2002 * do it... it's too complicated.
2003 */
2004 lrecs = xfs_btree_get_numrecs(left);
2005 if (cur->bc_ptrs[level] >= lrecs)
2006 goto out0;
2007
2008 /* Set up the right neighbor as "right". */
2009 error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2010 if (error)
2011 goto error0;
2012
2013 /* If it's full, it can't take another entry. */
2014 rrecs = xfs_btree_get_numrecs(right);
2015 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2016 goto out0;
2017
2018 XFS_BTREE_STATS_INC(cur, rshift);
2019 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2020
2021 /*
2022 * Make a hole at the start of the right neighbor block, then
2023 * copy the last left block entry to the hole.
2024 */
2025 if (level > 0) {
2026 /* It's a nonleaf. make a hole in the keys and ptrs */
2027 union xfs_btree_key *lkp;
2028 union xfs_btree_ptr *lpp;
2029 union xfs_btree_ptr *rpp;
2030
2031 lkp = xfs_btree_key_addr(cur, lrecs, left);
2032 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2033 rkp = xfs_btree_key_addr(cur, 1, right);
2034 rpp = xfs_btree_ptr_addr(cur, 1, right);
2035
2036#ifdef DEBUG
2037 for (i = rrecs - 1; i >= 0; i--) {
2038 error = xfs_btree_check_ptr(cur, rpp, i, level);
2039 if (error)
2040 goto error0;
2041 }
2042#endif
2043
2044 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2045 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2046
2047#ifdef DEBUG
2048 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2049 if (error)
2050 goto error0;
2051#endif
2052
2053 /* Now put the new data in, and log it. */
2054 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2055 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2056
2057 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2058 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2059
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002060 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2061 xfs_btree_key_addr(cur, 2, right)));
Christoph Hellwig9eaead52008-10-30 16:56:43 +11002062 } else {
2063 /* It's a leaf. make a hole in the records */
2064 union xfs_btree_rec *lrp;
2065 union xfs_btree_rec *rrp;
2066
2067 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2068 rrp = xfs_btree_rec_addr(cur, 1, right);
2069
2070 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2071
2072 /* Now put the new data in, and log it. */
2073 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2074 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2075
2076 cur->bc_ops->init_key_from_rec(&key, rrp);
2077 rkp = &key;
2078
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002079 ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2080 xfs_btree_rec_addr(cur, 2, right)));
Christoph Hellwig9eaead52008-10-30 16:56:43 +11002081 }
2082
2083 /*
2084 * Decrement and log left's numrecs, bump and log right's numrecs.
2085 */
2086 xfs_btree_set_numrecs(left, --lrecs);
2087 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2088
2089 xfs_btree_set_numrecs(right, ++rrecs);
2090 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2091
2092 /*
2093 * Using a temporary cursor, update the parent key values of the
2094 * block on the right.
2095 */
2096 error = xfs_btree_dup_cursor(cur, &tcur);
2097 if (error)
2098 goto error0;
2099 i = xfs_btree_lastrec(tcur, level);
2100 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2101
2102 error = xfs_btree_increment(tcur, level, &i);
2103 if (error)
2104 goto error1;
2105
2106 error = xfs_btree_updkey(tcur, rkp, level + 1);
2107 if (error)
2108 goto error1;
2109
2110 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2111
2112 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2113 *stat = 1;
2114 return 0;
2115
2116out0:
2117 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2118 *stat = 0;
2119 return 0;
2120
2121error0:
2122 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2123 return error;
2124
2125error1:
2126 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2127 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2128 return error;
2129}
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +11002130
2131/*
2132 * Split cur/level block in half.
2133 * Return new block number and the key to its first
2134 * record (to be inserted into parent).
2135 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11002136STATIC int /* error */
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +11002137xfs_btree_split(
2138 struct xfs_btree_cur *cur,
2139 int level,
2140 union xfs_btree_ptr *ptrp,
2141 union xfs_btree_key *key,
2142 struct xfs_btree_cur **curp,
2143 int *stat) /* success/failure */
2144{
2145 union xfs_btree_ptr lptr; /* left sibling block ptr */
2146 struct xfs_buf *lbp; /* left buffer pointer */
2147 struct xfs_btree_block *left; /* left btree block */
2148 union xfs_btree_ptr rptr; /* right sibling block ptr */
2149 struct xfs_buf *rbp; /* right buffer pointer */
2150 struct xfs_btree_block *right; /* right btree block */
2151 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2152 struct xfs_buf *rrbp; /* right-right buffer pointer */
2153 struct xfs_btree_block *rrblock; /* right-right btree block */
2154 int lrecs;
2155 int rrecs;
2156 int src_index;
2157 int error; /* error return value */
2158#ifdef DEBUG
2159 int i;
2160#endif
2161
2162 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2163 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2164
2165 XFS_BTREE_STATS_INC(cur, split);
2166
2167 /* Set up left block (current one). */
2168 left = xfs_btree_get_block(cur, level, &lbp);
2169
2170#ifdef DEBUG
2171 error = xfs_btree_check_block(cur, left, level, lbp);
2172 if (error)
2173 goto error0;
2174#endif
2175
2176 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2177
2178 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2179 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2180 if (error)
2181 goto error0;
2182 if (*stat == 0)
2183 goto out0;
2184 XFS_BTREE_STATS_INC(cur, alloc);
2185
2186 /* Set up the new block as "right". */
2187 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2188 if (error)
2189 goto error0;
2190
2191 /* Fill in the btree header for the new right block. */
2192 xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
2193
2194 /*
2195 * Split the entries between the old and the new block evenly.
2196 * Make sure that if there's an odd number of entries now, that
2197 * each new block will have the same number of entries.
2198 */
2199 lrecs = xfs_btree_get_numrecs(left);
2200 rrecs = lrecs / 2;
2201 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2202 rrecs++;
2203 src_index = (lrecs - rrecs + 1);
2204
2205 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2206
2207 /*
2208 * Copy btree block entries from the left block over to the
2209 * new block, the right. Update the right block and log the
2210 * changes.
2211 */
2212 if (level > 0) {
2213 /* It's a non-leaf. Move keys and pointers. */
2214 union xfs_btree_key *lkp; /* left btree key */
2215 union xfs_btree_ptr *lpp; /* left address pointer */
2216 union xfs_btree_key *rkp; /* right btree key */
2217 union xfs_btree_ptr *rpp; /* right address pointer */
2218
2219 lkp = xfs_btree_key_addr(cur, src_index, left);
2220 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2221 rkp = xfs_btree_key_addr(cur, 1, right);
2222 rpp = xfs_btree_ptr_addr(cur, 1, right);
2223
2224#ifdef DEBUG
2225 for (i = src_index; i < rrecs; i++) {
2226 error = xfs_btree_check_ptr(cur, lpp, i, level);
2227 if (error)
2228 goto error0;
2229 }
2230#endif
2231
2232 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2233 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2234
2235 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2236 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2237
2238 /* Grab the keys to the entries moved to the right block */
2239 xfs_btree_copy_keys(cur, key, rkp, 1);
2240 } else {
2241 /* It's a leaf. Move records. */
2242 union xfs_btree_rec *lrp; /* left record pointer */
2243 union xfs_btree_rec *rrp; /* right record pointer */
2244
2245 lrp = xfs_btree_rec_addr(cur, src_index, left);
2246 rrp = xfs_btree_rec_addr(cur, 1, right);
2247
2248 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2249 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2250
2251 cur->bc_ops->init_key_from_rec(key,
2252 xfs_btree_rec_addr(cur, 1, right));
2253 }
2254
2255
2256 /*
2257 * Find the left block number by looking in the buffer.
2258 * Adjust numrecs, sibling pointers.
2259 */
2260 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2261 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2262 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2263 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2264
2265 lrecs -= rrecs;
2266 xfs_btree_set_numrecs(left, lrecs);
2267 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2268
2269 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2270 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2271
2272 /*
2273 * If there's a block to the new block's right, make that block
2274 * point back to right instead of to left.
2275 */
2276 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2277 error = xfs_btree_read_buf_block(cur, &rrptr, level,
2278 0, &rrblock, &rrbp);
2279 if (error)
2280 goto error0;
2281 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2282 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2283 }
2284 /*
2285 * If the cursor is really in the right block, move it there.
2286 * If it's just pointing past the last entry in left, then we'll
2287 * insert there, so don't change anything in that case.
2288 */
2289 if (cur->bc_ptrs[level] > lrecs + 1) {
2290 xfs_btree_setbuf(cur, level, rbp);
2291 cur->bc_ptrs[level] -= lrecs;
2292 }
2293 /*
2294 * If there are more levels, we'll need another cursor which refers
2295 * the right block, no matter where this cursor was.
2296 */
2297 if (level + 1 < cur->bc_nlevels) {
2298 error = xfs_btree_dup_cursor(cur, curp);
2299 if (error)
2300 goto error0;
2301 (*curp)->bc_ptrs[level + 1]++;
2302 }
2303 *ptrp = rptr;
2304 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2305 *stat = 1;
2306 return 0;
2307out0:
2308 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2309 *stat = 0;
2310 return 0;
2311
2312error0:
2313 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2314 return error;
2315}
Christoph Hellwig344207c2008-10-30 16:57:16 +11002316
2317/*
Christoph Hellwigea77b0a2008-10-30 16:57:28 +11002318 * Copy the old inode root contents into a real block and make the
2319 * broot point to it.
2320 */
2321int /* error */
2322xfs_btree_new_iroot(
2323 struct xfs_btree_cur *cur, /* btree cursor */
2324 int *logflags, /* logging flags for inode */
2325 int *stat) /* return status - 0 fail */
2326{
2327 struct xfs_buf *cbp; /* buffer for cblock */
2328 struct xfs_btree_block *block; /* btree block */
2329 struct xfs_btree_block *cblock; /* child btree block */
2330 union xfs_btree_key *ckp; /* child key pointer */
2331 union xfs_btree_ptr *cpp; /* child ptr pointer */
2332 union xfs_btree_key *kp; /* pointer to btree key */
2333 union xfs_btree_ptr *pp; /* pointer to block addr */
2334 union xfs_btree_ptr nptr; /* new block addr */
2335 int level; /* btree level */
2336 int error; /* error return code */
2337#ifdef DEBUG
2338 int i; /* loop counter */
2339#endif
2340
2341 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2342 XFS_BTREE_STATS_INC(cur, newroot);
2343
2344 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2345
2346 level = cur->bc_nlevels - 1;
2347
2348 block = xfs_btree_get_iroot(cur);
2349 pp = xfs_btree_ptr_addr(cur, 1, block);
2350
2351 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2352 error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2353 if (error)
2354 goto error0;
2355 if (*stat == 0) {
2356 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2357 return 0;
2358 }
2359 XFS_BTREE_STATS_INC(cur, alloc);
2360
2361 /* Copy the root into a real block. */
2362 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2363 if (error)
2364 goto error0;
2365
2366 memcpy(cblock, block, xfs_btree_block_len(cur));
2367
2368 be16_add_cpu(&block->bb_level, 1);
2369 xfs_btree_set_numrecs(block, 1);
2370 cur->bc_nlevels++;
2371 cur->bc_ptrs[level + 1] = 1;
2372
2373 kp = xfs_btree_key_addr(cur, 1, block);
2374 ckp = xfs_btree_key_addr(cur, 1, cblock);
2375 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2376
2377 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2378#ifdef DEBUG
2379 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2380 error = xfs_btree_check_ptr(cur, pp, i, level);
2381 if (error)
2382 goto error0;
2383 }
2384#endif
2385 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2386
2387#ifdef DEBUG
2388 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2389 if (error)
2390 goto error0;
2391#endif
2392 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2393
2394 xfs_iroot_realloc(cur->bc_private.b.ip,
2395 1 - xfs_btree_get_numrecs(cblock),
2396 cur->bc_private.b.whichfork);
2397
2398 xfs_btree_setbuf(cur, level, cbp);
2399
2400 /*
2401 * Do all this logging at the end so that
2402 * the root is at the right level.
2403 */
2404 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2405 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2406 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2407
2408 *logflags |=
Eric Sandeen9d87c312009-01-14 23:22:07 -06002409 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
Christoph Hellwigea77b0a2008-10-30 16:57:28 +11002410 *stat = 1;
2411 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2412 return 0;
2413error0:
2414 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2415 return error;
2416}
2417
2418/*
Christoph Hellwig344207c2008-10-30 16:57:16 +11002419 * Allocate a new root block, fill it in.
2420 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11002421STATIC int /* error */
Christoph Hellwig344207c2008-10-30 16:57:16 +11002422xfs_btree_new_root(
2423 struct xfs_btree_cur *cur, /* btree cursor */
2424 int *stat) /* success/failure */
2425{
2426 struct xfs_btree_block *block; /* one half of the old root block */
2427 struct xfs_buf *bp; /* buffer containing block */
2428 int error; /* error return value */
2429 struct xfs_buf *lbp; /* left buffer pointer */
2430 struct xfs_btree_block *left; /* left btree block */
2431 struct xfs_buf *nbp; /* new (root) buffer */
2432 struct xfs_btree_block *new; /* new (root) btree block */
2433 int nptr; /* new value for key index, 1 or 2 */
2434 struct xfs_buf *rbp; /* right buffer pointer */
2435 struct xfs_btree_block *right; /* right btree block */
2436 union xfs_btree_ptr rptr;
2437 union xfs_btree_ptr lptr;
2438
2439 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2440 XFS_BTREE_STATS_INC(cur, newroot);
2441
2442 /* initialise our start point from the cursor */
2443 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2444
2445 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2446 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2447 if (error)
2448 goto error0;
2449 if (*stat == 0)
2450 goto out0;
2451 XFS_BTREE_STATS_INC(cur, alloc);
2452
2453 /* Set up the new block. */
2454 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2455 if (error)
2456 goto error0;
2457
2458 /* Set the root in the holding structure increasing the level by 1. */
2459 cur->bc_ops->set_root(cur, &lptr, 1);
2460
2461 /*
2462 * At the previous root level there are now two blocks: the old root,
2463 * and the new block generated when it was split. We don't know which
2464 * one the cursor is pointing at, so we set up variables "left" and
2465 * "right" for each case.
2466 */
2467 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2468
2469#ifdef DEBUG
2470 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2471 if (error)
2472 goto error0;
2473#endif
2474
2475 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2476 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2477 /* Our block is left, pick up the right block. */
2478 lbp = bp;
2479 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2480 left = block;
2481 error = xfs_btree_read_buf_block(cur, &rptr,
2482 cur->bc_nlevels - 1, 0, &right, &rbp);
2483 if (error)
2484 goto error0;
2485 bp = rbp;
2486 nptr = 1;
2487 } else {
2488 /* Our block is right, pick up the left block. */
2489 rbp = bp;
2490 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2491 right = block;
2492 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2493 error = xfs_btree_read_buf_block(cur, &lptr,
2494 cur->bc_nlevels - 1, 0, &left, &lbp);
2495 if (error)
2496 goto error0;
2497 bp = lbp;
2498 nptr = 2;
2499 }
2500 /* Fill in the new block's btree header and log it. */
2501 xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
2502 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2503 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2504 !xfs_btree_ptr_is_null(cur, &rptr));
2505
2506 /* Fill in the key data in the new root. */
2507 if (xfs_btree_get_level(left) > 0) {
2508 xfs_btree_copy_keys(cur,
2509 xfs_btree_key_addr(cur, 1, new),
2510 xfs_btree_key_addr(cur, 1, left), 1);
2511 xfs_btree_copy_keys(cur,
2512 xfs_btree_key_addr(cur, 2, new),
2513 xfs_btree_key_addr(cur, 1, right), 1);
2514 } else {
2515 cur->bc_ops->init_key_from_rec(
2516 xfs_btree_key_addr(cur, 1, new),
2517 xfs_btree_rec_addr(cur, 1, left));
2518 cur->bc_ops->init_key_from_rec(
2519 xfs_btree_key_addr(cur, 2, new),
2520 xfs_btree_rec_addr(cur, 1, right));
2521 }
2522 xfs_btree_log_keys(cur, nbp, 1, 2);
2523
2524 /* Fill in the pointer data in the new root. */
2525 xfs_btree_copy_ptrs(cur,
2526 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2527 xfs_btree_copy_ptrs(cur,
2528 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2529 xfs_btree_log_ptrs(cur, nbp, 1, 2);
2530
2531 /* Fix up the cursor. */
2532 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2533 cur->bc_ptrs[cur->bc_nlevels] = nptr;
2534 cur->bc_nlevels++;
2535 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2536 *stat = 1;
2537 return 0;
2538error0:
2539 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2540 return error;
2541out0:
2542 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2543 *stat = 0;
2544 return 0;
2545}
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002546
2547STATIC int
2548xfs_btree_make_block_unfull(
2549 struct xfs_btree_cur *cur, /* btree cursor */
2550 int level, /* btree level */
2551 int numrecs,/* # of recs in block */
2552 int *oindex,/* old tree index */
2553 int *index, /* new tree index */
2554 union xfs_btree_ptr *nptr, /* new btree ptr */
2555 struct xfs_btree_cur **ncur, /* new btree cursor */
2556 union xfs_btree_rec *nrec, /* new record */
2557 int *stat)
2558{
2559 union xfs_btree_key key; /* new btree key value */
2560 int error = 0;
2561
2562 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2563 level == cur->bc_nlevels - 1) {
2564 struct xfs_inode *ip = cur->bc_private.b.ip;
2565
2566 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2567 /* A root block that can be made bigger. */
2568
2569 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2570 } else {
2571 /* A root block that needs replacing */
2572 int logflags = 0;
2573
2574 error = xfs_btree_new_iroot(cur, &logflags, stat);
2575 if (error || *stat == 0)
2576 return error;
2577
2578 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2579 }
2580
2581 return 0;
2582 }
2583
2584 /* First, try shifting an entry to the right neighbor. */
2585 error = xfs_btree_rshift(cur, level, stat);
2586 if (error || *stat)
2587 return error;
2588
2589 /* Next, try shifting an entry to the left neighbor. */
2590 error = xfs_btree_lshift(cur, level, stat);
2591 if (error)
2592 return error;
2593
2594 if (*stat) {
2595 *oindex = *index = cur->bc_ptrs[level];
2596 return 0;
2597 }
2598
2599 /*
2600 * Next, try splitting the current block in half.
2601 *
2602 * If this works we have to re-set our variables because we
2603 * could be in a different block now.
2604 */
2605 error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2606 if (error || *stat == 0)
2607 return error;
2608
2609
2610 *index = cur->bc_ptrs[level];
2611 cur->bc_ops->init_rec_from_key(&key, nrec);
2612 return 0;
2613}
2614
2615/*
2616 * Insert one record/level. Return information to the caller
2617 * allowing the next level up to proceed if necessary.
2618 */
2619STATIC int
2620xfs_btree_insrec(
2621 struct xfs_btree_cur *cur, /* btree cursor */
2622 int level, /* level to insert record at */
2623 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
2624 union xfs_btree_rec *recp, /* i/o: record data inserted */
2625 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
2626 int *stat) /* success/failure */
2627{
2628 struct xfs_btree_block *block; /* btree block */
2629 struct xfs_buf *bp; /* buffer for block */
2630 union xfs_btree_key key; /* btree key */
2631 union xfs_btree_ptr nptr; /* new block ptr */
2632 struct xfs_btree_cur *ncur; /* new btree cursor */
2633 union xfs_btree_rec nrec; /* new record count */
2634 int optr; /* old key/record index */
2635 int ptr; /* key/record index */
2636 int numrecs;/* number of records */
2637 int error; /* error return value */
2638#ifdef DEBUG
2639 int i;
2640#endif
2641
2642 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2643 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2644
2645 ncur = NULL;
2646
2647 /*
2648 * If we have an external root pointer, and we've made it to the
2649 * root level, allocate a new root block and we're done.
2650 */
2651 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2652 (level >= cur->bc_nlevels)) {
2653 error = xfs_btree_new_root(cur, stat);
2654 xfs_btree_set_ptr_null(cur, ptrp);
2655
2656 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2657 return error;
2658 }
2659
2660 /* If we're off the left edge, return failure. */
2661 ptr = cur->bc_ptrs[level];
2662 if (ptr == 0) {
2663 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2664 *stat = 0;
2665 return 0;
2666 }
2667
2668 /* Make a key out of the record data to be inserted, and save it. */
2669 cur->bc_ops->init_key_from_rec(&key, recp);
2670
2671 optr = ptr;
2672
2673 XFS_BTREE_STATS_INC(cur, insrec);
2674
2675 /* Get pointers to the btree buffer and block. */
2676 block = xfs_btree_get_block(cur, level, &bp);
2677 numrecs = xfs_btree_get_numrecs(block);
2678
2679#ifdef DEBUG
2680 error = xfs_btree_check_block(cur, block, level, bp);
2681 if (error)
2682 goto error0;
2683
2684 /* Check that the new entry is being inserted in the right place. */
2685 if (ptr <= numrecs) {
2686 if (level == 0) {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002687 ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2688 xfs_btree_rec_addr(cur, ptr, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002689 } else {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002690 ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2691 xfs_btree_key_addr(cur, ptr, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002692 }
2693 }
2694#endif
2695
2696 /*
2697 * If the block is full, we can't insert the new entry until we
2698 * make the block un-full.
2699 */
2700 xfs_btree_set_ptr_null(cur, &nptr);
2701 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2702 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2703 &optr, &ptr, &nptr, &ncur, &nrec, stat);
2704 if (error || *stat == 0)
2705 goto error0;
2706 }
2707
2708 /*
2709 * The current block may have changed if the block was
2710 * previously full and we have just made space in it.
2711 */
2712 block = xfs_btree_get_block(cur, level, &bp);
2713 numrecs = xfs_btree_get_numrecs(block);
2714
2715#ifdef DEBUG
2716 error = xfs_btree_check_block(cur, block, level, bp);
2717 if (error)
2718 return error;
2719#endif
2720
2721 /*
2722 * At this point we know there's room for our new entry in the block
2723 * we're pointing at.
2724 */
2725 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2726
2727 if (level > 0) {
2728 /* It's a nonleaf. make a hole in the keys and ptrs */
2729 union xfs_btree_key *kp;
2730 union xfs_btree_ptr *pp;
2731
2732 kp = xfs_btree_key_addr(cur, ptr, block);
2733 pp = xfs_btree_ptr_addr(cur, ptr, block);
2734
2735#ifdef DEBUG
2736 for (i = numrecs - ptr; i >= 0; i--) {
2737 error = xfs_btree_check_ptr(cur, pp, i, level);
2738 if (error)
2739 return error;
2740 }
2741#endif
2742
2743 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2744 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2745
2746#ifdef DEBUG
2747 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2748 if (error)
2749 goto error0;
2750#endif
2751
2752 /* Now put the new data in, bump numrecs and log it. */
2753 xfs_btree_copy_keys(cur, kp, &key, 1);
2754 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2755 numrecs++;
2756 xfs_btree_set_numrecs(block, numrecs);
2757 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2758 xfs_btree_log_keys(cur, bp, ptr, numrecs);
2759#ifdef DEBUG
2760 if (ptr < numrecs) {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002761 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2762 xfs_btree_key_addr(cur, ptr + 1, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002763 }
2764#endif
2765 } else {
2766 /* It's a leaf. make a hole in the records */
2767 union xfs_btree_rec *rp;
2768
2769 rp = xfs_btree_rec_addr(cur, ptr, block);
2770
2771 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2772
2773 /* Now put the new data in, bump numrecs and log it. */
2774 xfs_btree_copy_recs(cur, rp, recp, 1);
2775 xfs_btree_set_numrecs(block, ++numrecs);
2776 xfs_btree_log_recs(cur, bp, ptr, numrecs);
2777#ifdef DEBUG
2778 if (ptr < numrecs) {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002779 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2780 xfs_btree_rec_addr(cur, ptr + 1, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002781 }
2782#endif
2783 }
2784
2785 /* Log the new number of records in the btree header. */
2786 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2787
2788 /* If we inserted at the start of a block, update the parents' keys. */
2789 if (optr == 1) {
2790 error = xfs_btree_updkey(cur, &key, level + 1);
2791 if (error)
2792 goto error0;
2793 }
2794
2795 /*
2796 * If we are tracking the last record in the tree and
2797 * we are at the far right edge of the tree, update it.
2798 */
2799 if (xfs_btree_is_lastrec(cur, block, level)) {
2800 cur->bc_ops->update_lastrec(cur, block, recp,
2801 ptr, LASTREC_INSREC);
2802 }
2803
2804 /*
2805 * Return the new block number, if any.
2806 * If there is one, give back a record value and a cursor too.
2807 */
2808 *ptrp = nptr;
2809 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2810 *recp = nrec;
2811 *curp = ncur;
2812 }
2813
2814 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2815 *stat = 1;
2816 return 0;
2817
2818error0:
2819 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2820 return error;
2821}
2822
2823/*
2824 * Insert the record at the point referenced by cur.
2825 *
2826 * A multi-level split of the tree on insert will invalidate the original
2827 * cursor. All callers of this function should assume that the cursor is
2828 * no longer valid and revalidate it.
2829 */
2830int
2831xfs_btree_insert(
2832 struct xfs_btree_cur *cur,
2833 int *stat)
2834{
2835 int error; /* error return value */
2836 int i; /* result value, 0 for failure */
2837 int level; /* current level number in btree */
2838 union xfs_btree_ptr nptr; /* new block number (split result) */
2839 struct xfs_btree_cur *ncur; /* new cursor (split result) */
2840 struct xfs_btree_cur *pcur; /* previous level's cursor */
2841 union xfs_btree_rec rec; /* record to insert */
2842
2843 level = 0;
2844 ncur = NULL;
2845 pcur = cur;
2846
2847 xfs_btree_set_ptr_null(cur, &nptr);
2848 cur->bc_ops->init_rec_from_cur(cur, &rec);
2849
2850 /*
2851 * Loop going up the tree, starting at the leaf level.
2852 * Stop when we don't get a split block, that must mean that
2853 * the insert is finished with this level.
2854 */
2855 do {
2856 /*
2857 * Insert nrec/nptr into this level of the tree.
2858 * Note if we fail, nptr will be null.
2859 */
2860 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
2861 if (error) {
2862 if (pcur != cur)
2863 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
2864 goto error0;
2865 }
2866
2867 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2868 level++;
2869
2870 /*
2871 * See if the cursor we just used is trash.
2872 * Can't trash the caller's cursor, but otherwise we should
2873 * if ncur is a new cursor or we're about to be done.
2874 */
2875 if (pcur != cur &&
2876 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
2877 /* Save the state from the cursor before we trash it */
2878 if (cur->bc_ops->update_cursor)
2879 cur->bc_ops->update_cursor(pcur, cur);
2880 cur->bc_nlevels = pcur->bc_nlevels;
2881 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
2882 }
2883 /* If we got a new cursor, switch to it. */
2884 if (ncur) {
2885 pcur = ncur;
2886 ncur = NULL;
2887 }
2888 } while (!xfs_btree_ptr_is_null(cur, &nptr));
2889
2890 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2891 *stat = i;
2892 return 0;
2893error0:
2894 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2895 return error;
2896}
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11002897
2898/*
2899 * Try to merge a non-leaf block back into the inode root.
2900 *
2901 * Note: the killroot names comes from the fact that we're effectively
2902 * killing the old root block. But because we can't just delete the
2903 * inode we have to copy the single block it was pointing to into the
2904 * inode.
2905 */
Eric Sandeend96f8f82009-07-02 00:09:33 -05002906STATIC int
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11002907xfs_btree_kill_iroot(
2908 struct xfs_btree_cur *cur)
2909{
2910 int whichfork = cur->bc_private.b.whichfork;
2911 struct xfs_inode *ip = cur->bc_private.b.ip;
2912 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
2913 struct xfs_btree_block *block;
2914 struct xfs_btree_block *cblock;
2915 union xfs_btree_key *kp;
2916 union xfs_btree_key *ckp;
2917 union xfs_btree_ptr *pp;
2918 union xfs_btree_ptr *cpp;
2919 struct xfs_buf *cbp;
2920 int level;
2921 int index;
2922 int numrecs;
2923#ifdef DEBUG
2924 union xfs_btree_ptr ptr;
2925 int i;
2926#endif
2927
2928 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2929
2930 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2931 ASSERT(cur->bc_nlevels > 1);
2932
2933 /*
2934 * Don't deal with the root block needs to be a leaf case.
2935 * We're just going to turn the thing back into extents anyway.
2936 */
2937 level = cur->bc_nlevels - 1;
2938 if (level == 1)
2939 goto out0;
2940
2941 /*
2942 * Give up if the root has multiple children.
2943 */
2944 block = xfs_btree_get_iroot(cur);
2945 if (xfs_btree_get_numrecs(block) != 1)
2946 goto out0;
2947
2948 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
2949 numrecs = xfs_btree_get_numrecs(cblock);
2950
2951 /*
2952 * Only do this if the next level will fit.
2953 * Then the data must be copied up to the inode,
2954 * instead of freeing the root you free the next level.
2955 */
2956 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
2957 goto out0;
2958
2959 XFS_BTREE_STATS_INC(cur, killroot);
2960
2961#ifdef DEBUG
2962 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
2963 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2964 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2965 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2966#endif
2967
2968 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
2969 if (index) {
2970 xfs_iroot_realloc(cur->bc_private.b.ip, index,
2971 cur->bc_private.b.whichfork);
Christoph Hellwig7cc95a82008-10-30 17:14:34 +11002972 block = ifp->if_broot;
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11002973 }
2974
2975 be16_add_cpu(&block->bb_numrecs, index);
2976 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
2977
2978 kp = xfs_btree_key_addr(cur, 1, block);
2979 ckp = xfs_btree_key_addr(cur, 1, cblock);
2980 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
2981
2982 pp = xfs_btree_ptr_addr(cur, 1, block);
2983 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2984#ifdef DEBUG
2985 for (i = 0; i < numrecs; i++) {
2986 int error;
2987
2988 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
2989 if (error) {
2990 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2991 return error;
2992 }
2993 }
2994#endif
2995 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
2996
2997 cur->bc_ops->free_block(cur, cbp);
2998 XFS_BTREE_STATS_INC(cur, free);
2999
3000 cur->bc_bufs[level - 1] = NULL;
3001 be16_add_cpu(&block->bb_level, -1);
3002 xfs_trans_log_inode(cur->bc_tp, ip,
Eric Sandeen9d87c312009-01-14 23:22:07 -06003003 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11003004 cur->bc_nlevels--;
3005out0:
3006 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3007 return 0;
3008}
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003009
Christoph Hellwigc0e59e12010-09-07 23:34:07 +00003010/*
3011 * Kill the current root node, and replace it with it's only child node.
3012 */
3013STATIC int
3014xfs_btree_kill_root(
3015 struct xfs_btree_cur *cur,
3016 struct xfs_buf *bp,
3017 int level,
3018 union xfs_btree_ptr *newroot)
3019{
3020 int error;
3021
3022 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3023 XFS_BTREE_STATS_INC(cur, killroot);
3024
3025 /*
3026 * Update the root pointer, decreasing the level by 1 and then
3027 * free the old root.
3028 */
3029 cur->bc_ops->set_root(cur, newroot, -1);
3030
3031 error = cur->bc_ops->free_block(cur, bp);
3032 if (error) {
3033 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3034 return error;
3035 }
3036
3037 XFS_BTREE_STATS_INC(cur, free);
3038
3039 cur->bc_bufs[level] = NULL;
3040 cur->bc_ra[level] = 0;
3041 cur->bc_nlevels--;
3042
3043 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3044 return 0;
3045}
3046
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003047STATIC int
3048xfs_btree_dec_cursor(
3049 struct xfs_btree_cur *cur,
3050 int level,
3051 int *stat)
3052{
3053 int error;
3054 int i;
3055
3056 if (level > 0) {
3057 error = xfs_btree_decrement(cur, level, &i);
3058 if (error)
3059 return error;
3060 }
3061
3062 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3063 *stat = 1;
3064 return 0;
3065}
3066
3067/*
3068 * Single level of the btree record deletion routine.
3069 * Delete record pointed to by cur/level.
3070 * Remove the record from its block then rebalance the tree.
3071 * Return 0 for error, 1 for done, 2 to go on to the next level.
3072 */
3073STATIC int /* error */
3074xfs_btree_delrec(
3075 struct xfs_btree_cur *cur, /* btree cursor */
3076 int level, /* level removing record from */
3077 int *stat) /* fail/done/go-on */
3078{
3079 struct xfs_btree_block *block; /* btree block */
3080 union xfs_btree_ptr cptr; /* current block ptr */
3081 struct xfs_buf *bp; /* buffer for block */
3082 int error; /* error return value */
3083 int i; /* loop counter */
3084 union xfs_btree_key key; /* storage for keyp */
3085 union xfs_btree_key *keyp = &key; /* passed to the next level */
3086 union xfs_btree_ptr lptr; /* left sibling block ptr */
3087 struct xfs_buf *lbp; /* left buffer pointer */
3088 struct xfs_btree_block *left; /* left btree block */
3089 int lrecs = 0; /* left record count */
3090 int ptr; /* key/record index */
3091 union xfs_btree_ptr rptr; /* right sibling block ptr */
3092 struct xfs_buf *rbp; /* right buffer pointer */
3093 struct xfs_btree_block *right; /* right btree block */
3094 struct xfs_btree_block *rrblock; /* right-right btree block */
3095 struct xfs_buf *rrbp; /* right-right buffer pointer */
3096 int rrecs = 0; /* right record count */
3097 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3098 int numrecs; /* temporary numrec count */
3099
3100 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3101 XFS_BTREE_TRACE_ARGI(cur, level);
3102
3103 tcur = NULL;
3104
3105 /* Get the index of the entry being deleted, check for nothing there. */
3106 ptr = cur->bc_ptrs[level];
3107 if (ptr == 0) {
3108 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3109 *stat = 0;
3110 return 0;
3111 }
3112
3113 /* Get the buffer & block containing the record or key/ptr. */
3114 block = xfs_btree_get_block(cur, level, &bp);
3115 numrecs = xfs_btree_get_numrecs(block);
3116
3117#ifdef DEBUG
3118 error = xfs_btree_check_block(cur, block, level, bp);
3119 if (error)
3120 goto error0;
3121#endif
3122
3123 /* Fail if we're off the end of the block. */
3124 if (ptr > numrecs) {
3125 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3126 *stat = 0;
3127 return 0;
3128 }
3129
3130 XFS_BTREE_STATS_INC(cur, delrec);
3131 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3132
3133 /* Excise the entries being deleted. */
3134 if (level > 0) {
3135 /* It's a nonleaf. operate on keys and ptrs */
3136 union xfs_btree_key *lkp;
3137 union xfs_btree_ptr *lpp;
3138
3139 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3140 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3141
3142#ifdef DEBUG
3143 for (i = 0; i < numrecs - ptr; i++) {
3144 error = xfs_btree_check_ptr(cur, lpp, i, level);
3145 if (error)
3146 goto error0;
3147 }
3148#endif
3149
3150 if (ptr < numrecs) {
3151 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3152 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3153 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3154 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3155 }
3156
3157 /*
3158 * If it's the first record in the block, we'll need to pass a
3159 * key up to the next level (updkey).
3160 */
3161 if (ptr == 1)
3162 keyp = xfs_btree_key_addr(cur, 1, block);
3163 } else {
3164 /* It's a leaf. operate on records */
3165 if (ptr < numrecs) {
3166 xfs_btree_shift_recs(cur,
3167 xfs_btree_rec_addr(cur, ptr + 1, block),
3168 -1, numrecs - ptr);
3169 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3170 }
3171
3172 /*
3173 * If it's the first record in the block, we'll need a key
3174 * structure to pass up to the next level (updkey).
3175 */
3176 if (ptr == 1) {
3177 cur->bc_ops->init_key_from_rec(&key,
3178 xfs_btree_rec_addr(cur, 1, block));
3179 keyp = &key;
3180 }
3181 }
3182
3183 /*
3184 * Decrement and log the number of entries in the block.
3185 */
3186 xfs_btree_set_numrecs(block, --numrecs);
3187 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3188
3189 /*
3190 * If we are tracking the last record in the tree and
3191 * we are at the far right edge of the tree, update it.
3192 */
3193 if (xfs_btree_is_lastrec(cur, block, level)) {
3194 cur->bc_ops->update_lastrec(cur, block, NULL,
3195 ptr, LASTREC_DELREC);
3196 }
3197
3198 /*
3199 * We're at the root level. First, shrink the root block in-memory.
3200 * Try to get rid of the next level down. If we can't then there's
3201 * nothing left to do.
3202 */
3203 if (level == cur->bc_nlevels - 1) {
3204 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3205 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3206 cur->bc_private.b.whichfork);
3207
3208 error = xfs_btree_kill_iroot(cur);
3209 if (error)
3210 goto error0;
3211
3212 error = xfs_btree_dec_cursor(cur, level, stat);
3213 if (error)
3214 goto error0;
3215 *stat = 1;
3216 return 0;
3217 }
3218
3219 /*
3220 * If this is the root level, and there's only one entry left,
3221 * and it's NOT the leaf level, then we can get rid of this
3222 * level.
3223 */
3224 if (numrecs == 1 && level > 0) {
3225 union xfs_btree_ptr *pp;
3226 /*
3227 * pp is still set to the first pointer in the block.
3228 * Make it the new root of the btree.
3229 */
3230 pp = xfs_btree_ptr_addr(cur, 1, block);
Christoph Hellwigc0e59e12010-09-07 23:34:07 +00003231 error = xfs_btree_kill_root(cur, bp, level, pp);
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003232 if (error)
3233 goto error0;
3234 } else if (level > 0) {
3235 error = xfs_btree_dec_cursor(cur, level, stat);
3236 if (error)
3237 goto error0;
3238 }
3239 *stat = 1;
3240 return 0;
3241 }
3242
3243 /*
3244 * If we deleted the leftmost entry in the block, update the
3245 * key values above us in the tree.
3246 */
3247 if (ptr == 1) {
3248 error = xfs_btree_updkey(cur, keyp, level + 1);
3249 if (error)
3250 goto error0;
3251 }
3252
3253 /*
3254 * If the number of records remaining in the block is at least
3255 * the minimum, we're done.
3256 */
3257 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3258 error = xfs_btree_dec_cursor(cur, level, stat);
3259 if (error)
3260 goto error0;
3261 return 0;
3262 }
3263
3264 /*
3265 * Otherwise, we have to move some records around to keep the
3266 * tree balanced. Look at the left and right sibling blocks to
3267 * see if we can re-balance by moving only one record.
3268 */
3269 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3270 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3271
3272 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3273 /*
3274 * One child of root, need to get a chance to copy its contents
3275 * into the root and delete it. Can't go up to next level,
3276 * there's nothing to delete there.
3277 */
3278 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3279 xfs_btree_ptr_is_null(cur, &lptr) &&
3280 level == cur->bc_nlevels - 2) {
3281 error = xfs_btree_kill_iroot(cur);
3282 if (!error)
3283 error = xfs_btree_dec_cursor(cur, level, stat);
3284 if (error)
3285 goto error0;
3286 return 0;
3287 }
3288 }
3289
3290 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3291 !xfs_btree_ptr_is_null(cur, &lptr));
3292
3293 /*
3294 * Duplicate the cursor so our btree manipulations here won't
3295 * disrupt the next level up.
3296 */
3297 error = xfs_btree_dup_cursor(cur, &tcur);
3298 if (error)
3299 goto error0;
3300
3301 /*
3302 * If there's a right sibling, see if it's ok to shift an entry
3303 * out of it.
3304 */
3305 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3306 /*
3307 * Move the temp cursor to the last entry in the next block.
3308 * Actually any entry but the first would suffice.
3309 */
3310 i = xfs_btree_lastrec(tcur, level);
3311 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3312
3313 error = xfs_btree_increment(tcur, level, &i);
3314 if (error)
3315 goto error0;
3316 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3317
3318 i = xfs_btree_lastrec(tcur, level);
3319 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3320
3321 /* Grab a pointer to the block. */
3322 right = xfs_btree_get_block(tcur, level, &rbp);
3323#ifdef DEBUG
3324 error = xfs_btree_check_block(tcur, right, level, rbp);
3325 if (error)
3326 goto error0;
3327#endif
3328 /* Grab the current block number, for future use. */
3329 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3330
3331 /*
3332 * If right block is full enough so that removing one entry
3333 * won't make it too empty, and left-shifting an entry out
3334 * of right to us works, we're done.
3335 */
3336 if (xfs_btree_get_numrecs(right) - 1 >=
3337 cur->bc_ops->get_minrecs(tcur, level)) {
3338 error = xfs_btree_lshift(tcur, level, &i);
3339 if (error)
3340 goto error0;
3341 if (i) {
3342 ASSERT(xfs_btree_get_numrecs(block) >=
3343 cur->bc_ops->get_minrecs(tcur, level));
3344
3345 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3346 tcur = NULL;
3347
3348 error = xfs_btree_dec_cursor(cur, level, stat);
3349 if (error)
3350 goto error0;
3351 return 0;
3352 }
3353 }
3354
3355 /*
3356 * Otherwise, grab the number of records in right for
3357 * future reference, and fix up the temp cursor to point
3358 * to our block again (last record).
3359 */
3360 rrecs = xfs_btree_get_numrecs(right);
3361 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3362 i = xfs_btree_firstrec(tcur, level);
3363 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3364
3365 error = xfs_btree_decrement(tcur, level, &i);
3366 if (error)
3367 goto error0;
3368 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3369 }
3370 }
3371
3372 /*
3373 * If there's a left sibling, see if it's ok to shift an entry
3374 * out of it.
3375 */
3376 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3377 /*
3378 * Move the temp cursor to the first entry in the
3379 * previous block.
3380 */
3381 i = xfs_btree_firstrec(tcur, level);
3382 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3383
3384 error = xfs_btree_decrement(tcur, level, &i);
3385 if (error)
3386 goto error0;
3387 i = xfs_btree_firstrec(tcur, level);
3388 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3389
3390 /* Grab a pointer to the block. */
3391 left = xfs_btree_get_block(tcur, level, &lbp);
3392#ifdef DEBUG
3393 error = xfs_btree_check_block(cur, left, level, lbp);
3394 if (error)
3395 goto error0;
3396#endif
3397 /* Grab the current block number, for future use. */
3398 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3399
3400 /*
3401 * If left block is full enough so that removing one entry
3402 * won't make it too empty, and right-shifting an entry out
3403 * of left to us works, we're done.
3404 */
3405 if (xfs_btree_get_numrecs(left) - 1 >=
3406 cur->bc_ops->get_minrecs(tcur, level)) {
3407 error = xfs_btree_rshift(tcur, level, &i);
3408 if (error)
3409 goto error0;
3410 if (i) {
3411 ASSERT(xfs_btree_get_numrecs(block) >=
3412 cur->bc_ops->get_minrecs(tcur, level));
3413 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3414 tcur = NULL;
3415 if (level == 0)
3416 cur->bc_ptrs[0]++;
3417 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3418 *stat = 1;
3419 return 0;
3420 }
3421 }
3422
3423 /*
3424 * Otherwise, grab the number of records in right for
3425 * future reference.
3426 */
3427 lrecs = xfs_btree_get_numrecs(left);
3428 }
3429
3430 /* Delete the temp cursor, we're done with it. */
3431 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3432 tcur = NULL;
3433
3434 /* If here, we need to do a join to keep the tree balanced. */
3435 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3436
3437 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3438 lrecs + xfs_btree_get_numrecs(block) <=
3439 cur->bc_ops->get_maxrecs(cur, level)) {
3440 /*
3441 * Set "right" to be the starting block,
3442 * "left" to be the left neighbor.
3443 */
3444 rptr = cptr;
3445 right = block;
3446 rbp = bp;
3447 error = xfs_btree_read_buf_block(cur, &lptr, level,
3448 0, &left, &lbp);
3449 if (error)
3450 goto error0;
3451
3452 /*
3453 * If that won't work, see if we can join with the right neighbor block.
3454 */
3455 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3456 rrecs + xfs_btree_get_numrecs(block) <=
3457 cur->bc_ops->get_maxrecs(cur, level)) {
3458 /*
3459 * Set "left" to be the starting block,
3460 * "right" to be the right neighbor.
3461 */
3462 lptr = cptr;
3463 left = block;
3464 lbp = bp;
3465 error = xfs_btree_read_buf_block(cur, &rptr, level,
3466 0, &right, &rbp);
3467 if (error)
3468 goto error0;
3469
3470 /*
3471 * Otherwise, we can't fix the imbalance.
3472 * Just return. This is probably a logic error, but it's not fatal.
3473 */
3474 } else {
3475 error = xfs_btree_dec_cursor(cur, level, stat);
3476 if (error)
3477 goto error0;
3478 return 0;
3479 }
3480
3481 rrecs = xfs_btree_get_numrecs(right);
3482 lrecs = xfs_btree_get_numrecs(left);
3483
3484 /*
3485 * We're now going to join "left" and "right" by moving all the stuff
3486 * in "right" to "left" and deleting "right".
3487 */
3488 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3489 if (level > 0) {
3490 /* It's a non-leaf. Move keys and pointers. */
3491 union xfs_btree_key *lkp; /* left btree key */
3492 union xfs_btree_ptr *lpp; /* left address pointer */
3493 union xfs_btree_key *rkp; /* right btree key */
3494 union xfs_btree_ptr *rpp; /* right address pointer */
3495
3496 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3497 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3498 rkp = xfs_btree_key_addr(cur, 1, right);
3499 rpp = xfs_btree_ptr_addr(cur, 1, right);
3500#ifdef DEBUG
3501 for (i = 1; i < rrecs; i++) {
3502 error = xfs_btree_check_ptr(cur, rpp, i, level);
3503 if (error)
3504 goto error0;
3505 }
3506#endif
3507 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3508 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3509
3510 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3511 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3512 } else {
3513 /* It's a leaf. Move records. */
3514 union xfs_btree_rec *lrp; /* left record pointer */
3515 union xfs_btree_rec *rrp; /* right record pointer */
3516
3517 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3518 rrp = xfs_btree_rec_addr(cur, 1, right);
3519
3520 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3521 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3522 }
3523
3524 XFS_BTREE_STATS_INC(cur, join);
3525
3526 /*
Malcolm Parsons9da096f2009-03-29 09:55:42 +02003527 * Fix up the number of records and right block pointer in the
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003528 * surviving block, and log it.
3529 */
3530 xfs_btree_set_numrecs(left, lrecs + rrecs);
3531 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3532 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3533 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3534
3535 /* If there is a right sibling, point it to the remaining block. */
3536 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3537 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3538 error = xfs_btree_read_buf_block(cur, &cptr, level,
3539 0, &rrblock, &rrbp);
3540 if (error)
3541 goto error0;
3542 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3543 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3544 }
3545
3546 /* Free the deleted block. */
3547 error = cur->bc_ops->free_block(cur, rbp);
3548 if (error)
3549 goto error0;
3550 XFS_BTREE_STATS_INC(cur, free);
3551
3552 /*
3553 * If we joined with the left neighbor, set the buffer in the
3554 * cursor to the left block, and fix up the index.
3555 */
3556 if (bp != lbp) {
3557 cur->bc_bufs[level] = lbp;
3558 cur->bc_ptrs[level] += lrecs;
3559 cur->bc_ra[level] = 0;
3560 }
3561 /*
3562 * If we joined with the right neighbor and there's a level above
3563 * us, increment the cursor at that level.
3564 */
3565 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3566 (level + 1 < cur->bc_nlevels)) {
3567 error = xfs_btree_increment(cur, level + 1, &i);
3568 if (error)
3569 goto error0;
3570 }
3571
3572 /*
3573 * Readjust the ptr at this level if it's not a leaf, since it's
3574 * still pointing at the deletion point, which makes the cursor
3575 * inconsistent. If this makes the ptr 0, the caller fixes it up.
3576 * We can't use decrement because it would change the next level up.
3577 */
3578 if (level > 0)
3579 cur->bc_ptrs[level]--;
3580
3581 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3582 /* Return value means the next level up has something to do. */
3583 *stat = 2;
3584 return 0;
3585
3586error0:
3587 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3588 if (tcur)
3589 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3590 return error;
3591}
3592
3593/*
3594 * Delete the record pointed to by cur.
3595 * The cursor refers to the place where the record was (could be inserted)
3596 * when the operation returns.
3597 */
3598int /* error */
3599xfs_btree_delete(
3600 struct xfs_btree_cur *cur,
3601 int *stat) /* success/failure */
3602{
3603 int error; /* error return value */
3604 int level;
3605 int i;
3606
3607 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3608
3609 /*
3610 * Go up the tree, starting at leaf level.
3611 *
3612 * If 2 is returned then a join was done; go to the next level.
3613 * Otherwise we are done.
3614 */
3615 for (level = 0, i = 2; i == 2; level++) {
3616 error = xfs_btree_delrec(cur, level, &i);
3617 if (error)
3618 goto error0;
3619 }
3620
3621 if (i == 0) {
3622 for (level = 1; level < cur->bc_nlevels; level++) {
3623 if (cur->bc_ptrs[level] == 0) {
3624 error = xfs_btree_decrement(cur, level, &i);
3625 if (error)
3626 goto error0;
3627 break;
3628 }
3629 }
3630 }
3631
3632 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3633 *stat = i;
3634 return 0;
3635error0:
3636 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3637 return error;
3638}
Christoph Hellwig8cc938f2008-10-30 16:58:11 +11003639
3640/*
3641 * Get the data from the pointed-to record.
3642 */
3643int /* error */
3644xfs_btree_get_rec(
3645 struct xfs_btree_cur *cur, /* btree cursor */
3646 union xfs_btree_rec **recp, /* output: btree record */
3647 int *stat) /* output: success/failure */
3648{
3649 struct xfs_btree_block *block; /* btree block */
3650 struct xfs_buf *bp; /* buffer pointer */
3651 int ptr; /* record number */
3652#ifdef DEBUG
3653 int error; /* error return value */
3654#endif
3655
3656 ptr = cur->bc_ptrs[0];
3657 block = xfs_btree_get_block(cur, 0, &bp);
3658
3659#ifdef DEBUG
3660 error = xfs_btree_check_block(cur, block, 0, bp);
3661 if (error)
3662 return error;
3663#endif
3664
3665 /*
3666 * Off the right end or left end, return failure.
3667 */
3668 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3669 *stat = 0;
3670 return 0;
3671 }
3672
3673 /*
3674 * Point to the record and extract its data.
3675 */
3676 *recp = xfs_btree_rec_addr(cur, ptr, block);
3677 *stat = 1;
3678 return 0;
3679}