blob: cabf4b5604aa6dff065ff2ab428a6e6efdd97a00 [file] [log] [blame]
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"
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include "xfs_error.h"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000036#include "xfs_trace.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38/*
39 * Cursor allocation zone.
40 */
41kmem_zone_t *xfs_btree_cur_zone;
42
43/*
44 * Btree magic numbers.
45 */
Christoph Hellwigcdcf43332008-08-13 16:23:50 +100046const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
48};
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110051STATIC int /* error (0 or EFSCORRUPTED) */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110052xfs_btree_check_lblock(
53 struct xfs_btree_cur *cur, /* btree cursor */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110054 struct xfs_btree_block *block, /* btree long form block pointer */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110055 int level, /* level of the btree block */
56 struct xfs_buf *bp) /* buffer for block, if any */
57{
58 int lblock_ok; /* block passes checks */
59 struct xfs_mount *mp; /* file system mount point */
60
61 mp = cur->bc_mp;
62 lblock_ok =
63 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
64 be16_to_cpu(block->bb_level) == level &&
65 be16_to_cpu(block->bb_numrecs) <=
Christoph Hellwigce5e42d2008-10-30 16:55:23 +110066 cur->bc_ops->get_maxrecs(cur, level) &&
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110067 block->bb_u.l.bb_leftsib &&
Christoph Hellwig69ef9212011-07-08 14:36:05 +020068 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110069 XFS_FSB_SANITY_CHECK(mp,
70 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
71 block->bb_u.l.bb_rightsib &&
Christoph Hellwig69ef9212011-07-08 14:36:05 +020072 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110073 XFS_FSB_SANITY_CHECK(mp,
74 be64_to_cpu(block->bb_u.l.bb_rightsib)));
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110075 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
76 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
77 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
78 if (bp)
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000079 trace_xfs_btree_corrupt(bp, _RET_IP_);
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110080 XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
81 mp);
82 return XFS_ERROR(EFSCORRUPTED);
83 }
84 return 0;
85}
86
Christoph Hellwig3cc75242008-10-30 16:58:41 +110087STATIC int /* error (0 or EFSCORRUPTED) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070088xfs_btree_check_sblock(
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110089 struct xfs_btree_cur *cur, /* btree cursor */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +110090 struct xfs_btree_block *block, /* btree short form block pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 int level, /* level of the btree block */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110092 struct xfs_buf *bp) /* buffer containing block */
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +110094 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
95 struct xfs_agf *agf; /* ag. freespace structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 xfs_agblock_t agflen; /* native ag. freespace length */
97 int sblock_ok; /* block passes checks */
98
99 agbp = cur->bc_private.a.agbp;
100 agf = XFS_BUF_TO_AGF(agbp);
Christoph Hellwig16259e72005-11-02 15:11:25 +1100101 agflen = be32_to_cpu(agf->agf_length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 sblock_ok =
Christoph Hellwig16259e72005-11-02 15:11:25 +1100103 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
104 be16_to_cpu(block->bb_level) == level &&
105 be16_to_cpu(block->bb_numrecs) <=
Christoph Hellwigce5e42d2008-10-30 16:55:23 +1100106 cur->bc_ops->get_maxrecs(cur, level) &&
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200107 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100108 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
109 block->bb_u.s.bb_leftsib &&
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200110 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100111 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
112 block->bb_u.s.bb_rightsib;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
114 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
115 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
116 if (bp)
Christoph Hellwig0b1b2132009-12-14 23:14:59 +0000117 trace_xfs_btree_corrupt(bp, _RET_IP_);
Eric Sandeene0c222c2009-07-20 10:52:15 -0500118 XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
119 XFS_ERRLEVEL_LOW, cur->bc_mp, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 return XFS_ERROR(EFSCORRUPTED);
121 }
122 return 0;
123}
124
125/*
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100126 * Debug routine: check that block header is ok.
127 */
128int
129xfs_btree_check_block(
130 struct xfs_btree_cur *cur, /* btree cursor */
131 struct xfs_btree_block *block, /* generic btree block pointer */
132 int level, /* level of the btree block */
133 struct xfs_buf *bp) /* buffer containing block, if any */
134{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100135 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
136 return xfs_btree_check_lblock(cur, block, level, bp);
137 else
138 return xfs_btree_check_sblock(cur, block, level, bp);
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100139}
140
141/*
142 * Check that (long) pointer is ok.
143 */
144int /* error (0 or EFSCORRUPTED) */
145xfs_btree_check_lptr(
146 struct xfs_btree_cur *cur, /* btree cursor */
147 xfs_dfsbno_t bno, /* btree block disk address */
148 int level) /* btree block level */
149{
150 XFS_WANT_CORRUPTED_RETURN(
151 level > 0 &&
152 bno != NULLDFSBNO &&
153 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
154 return 0;
155}
156
Lachlan McIlroy24ee0e42008-10-30 17:05:26 +1100157#ifdef DEBUG
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100158/*
159 * Check that (short) pointer is ok.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100161STATIC int /* error (0 or EFSCORRUPTED) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162xfs_btree_check_sptr(
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100163 struct xfs_btree_cur *cur, /* btree cursor */
164 xfs_agblock_t bno, /* btree block disk address */
165 int level) /* btree block level */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100167 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 XFS_WANT_CORRUPTED_RETURN(
170 level > 0 &&
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100171 bno != NULLAGBLOCK &&
172 bno != 0 &&
173 bno < agblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 return 0;
175}
176
177/*
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100178 * Check that block ptr is ok.
179 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100180STATIC int /* error (0 or EFSCORRUPTED) */
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100181xfs_btree_check_ptr(
182 struct xfs_btree_cur *cur, /* btree cursor */
183 union xfs_btree_ptr *ptr, /* btree block disk address */
184 int index, /* offset from ptr to check */
185 int level) /* btree block level */
186{
187 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
188 return xfs_btree_check_lptr(cur,
189 be64_to_cpu((&ptr->l)[index]), level);
190 } else {
191 return xfs_btree_check_sptr(cur,
192 be32_to_cpu((&ptr->s)[index]), level);
193 }
194}
Lachlan McIlroy24ee0e42008-10-30 17:05:26 +1100195#endif
Christoph Hellwiga23f6ef2008-10-30 16:54:53 +1100196
197/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 * Delete the btree cursor.
199 */
200void
201xfs_btree_del_cursor(
202 xfs_btree_cur_t *cur, /* btree cursor */
203 int error) /* del because of error */
204{
205 int i; /* btree level */
206
207 /*
208 * Clear the buffer pointers, and release the buffers.
209 * If we're doing this in the face of an error, we
210 * need to make sure to inspect all of the entries
211 * in the bc_bufs array for buffers to be unlocked.
212 * This is because some of the btree code works from
213 * level n down to 0, and if we get an error along
214 * the way we won't have initialized all the entries
215 * down to 0.
216 */
217 for (i = 0; i < cur->bc_nlevels; i++) {
218 if (cur->bc_bufs[i])
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000219 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 else if (!error)
221 break;
222 }
223 /*
224 * Can't free a bmap cursor without having dealt with the
225 * allocated indirect blocks' accounting.
226 */
227 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
228 cur->bc_private.b.allocated == 0);
229 /*
230 * Free the cursor.
231 */
232 kmem_zone_free(xfs_btree_cur_zone, cur);
233}
234
235/*
236 * Duplicate the btree cursor.
237 * Allocate a new one, copy the record, re-get the buffers.
238 */
239int /* error */
240xfs_btree_dup_cursor(
241 xfs_btree_cur_t *cur, /* input cursor */
242 xfs_btree_cur_t **ncur) /* output cursor */
243{
244 xfs_buf_t *bp; /* btree block's buffer pointer */
245 int error; /* error return value */
246 int i; /* level number of btree block */
247 xfs_mount_t *mp; /* mount structure for filesystem */
248 xfs_btree_cur_t *new; /* new cursor value */
249 xfs_trans_t *tp; /* transaction pointer, can be NULL */
250
251 tp = cur->bc_tp;
252 mp = cur->bc_mp;
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 /*
255 * Allocate a new cursor like the old one.
256 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100257 new = cur->bc_ops->dup_cursor(cur);
258
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 /*
260 * Copy the record currently in the cursor.
261 */
262 new->bc_rec = cur->bc_rec;
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100263
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 /*
265 * For each level current, re-get the buffer and copy the ptr value.
266 */
267 for (i = 0; i < new->bc_nlevels; i++) {
268 new->bc_ptrs[i] = cur->bc_ptrs[i];
269 new->bc_ra[i] = cur->bc_ra[i];
270 if ((bp = cur->bc_bufs[i])) {
271 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
272 XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
273 xfs_btree_del_cursor(new, error);
274 *ncur = NULL;
275 return error;
276 }
277 new->bc_bufs[i] = bp;
278 ASSERT(bp);
279 ASSERT(!XFS_BUF_GETERROR(bp));
280 } else
281 new->bc_bufs[i] = NULL;
282 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 *ncur = new;
284 return 0;
285}
286
287/*
Christoph Hellwig65f1eae2008-10-30 16:55:34 +1100288 * XFS btree block layout and addressing:
289 *
290 * There are two types of blocks in the btree: leaf and non-leaf blocks.
291 *
292 * The leaf record start with a header then followed by records containing
293 * the values. A non-leaf block also starts with the same header, and
294 * then first contains lookup keys followed by an equal number of pointers
295 * to the btree blocks at the previous level.
296 *
297 * +--------+-------+-------+-------+-------+-------+-------+
298 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
299 * +--------+-------+-------+-------+-------+-------+-------+
300 *
301 * +--------+-------+-------+-------+-------+-------+-------+
302 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
303 * +--------+-------+-------+-------+-------+-------+-------+
304 *
305 * The header is called struct xfs_btree_block for reasons better left unknown
306 * and comes in different versions for short (32bit) and long (64bit) block
307 * pointers. The record and key structures are defined by the btree instances
308 * and opaque to the btree core. The block pointers are simple disk endian
309 * integers, available in a short (32bit) and long (64bit) variant.
310 *
311 * The helpers below calculate the offset of a given record, key or pointer
312 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
313 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
314 * inside the btree block is done using indices starting at one, not zero!
315 */
316
317/*
318 * Return size of the btree block header for this btree instance.
319 */
320static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
321{
322 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100323 XFS_BTREE_LBLOCK_LEN :
324 XFS_BTREE_SBLOCK_LEN;
Christoph Hellwig65f1eae2008-10-30 16:55:34 +1100325}
326
327/*
328 * Return size of btree block pointers for this btree instance.
329 */
330static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
331{
332 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
333 sizeof(__be64) : sizeof(__be32);
334}
335
336/*
337 * Calculate offset of the n-th record in a btree block.
338 */
339STATIC size_t
340xfs_btree_rec_offset(
341 struct xfs_btree_cur *cur,
342 int n)
343{
344 return xfs_btree_block_len(cur) +
345 (n - 1) * cur->bc_ops->rec_len;
346}
347
348/*
349 * Calculate offset of the n-th key in a btree block.
350 */
351STATIC size_t
352xfs_btree_key_offset(
353 struct xfs_btree_cur *cur,
354 int n)
355{
356 return xfs_btree_block_len(cur) +
357 (n - 1) * cur->bc_ops->key_len;
358}
359
360/*
361 * Calculate offset of the n-th block pointer in a btree block.
362 */
363STATIC size_t
364xfs_btree_ptr_offset(
365 struct xfs_btree_cur *cur,
366 int n,
367 int level)
368{
369 return xfs_btree_block_len(cur) +
370 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
371 (n - 1) * xfs_btree_ptr_len(cur);
372}
373
374/*
375 * Return a pointer to the n-th record in the btree block.
376 */
377STATIC union xfs_btree_rec *
378xfs_btree_rec_addr(
379 struct xfs_btree_cur *cur,
380 int n,
381 struct xfs_btree_block *block)
382{
383 return (union xfs_btree_rec *)
384 ((char *)block + xfs_btree_rec_offset(cur, n));
385}
386
387/*
388 * Return a pointer to the n-th key in the btree block.
389 */
390STATIC union xfs_btree_key *
391xfs_btree_key_addr(
392 struct xfs_btree_cur *cur,
393 int n,
394 struct xfs_btree_block *block)
395{
396 return (union xfs_btree_key *)
397 ((char *)block + xfs_btree_key_offset(cur, n));
398}
399
400/*
401 * Return a pointer to the n-th block pointer in the btree block.
402 */
403STATIC union xfs_btree_ptr *
404xfs_btree_ptr_addr(
405 struct xfs_btree_cur *cur,
406 int n,
407 struct xfs_btree_block *block)
408{
409 int level = xfs_btree_get_level(block);
410
411 ASSERT(block->bb_level != 0);
412
413 return (union xfs_btree_ptr *)
414 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
415}
416
417/*
Christoph Hellwig8186e512008-10-30 16:54:22 +1100418 * Get a the root block which is stored in the inode.
419 *
420 * For now this btree implementation assumes the btree root is always
421 * stored in the if_broot field of an inode fork.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 */
Christoph Hellwig8186e512008-10-30 16:54:22 +1100423STATIC struct xfs_btree_block *
424xfs_btree_get_iroot(
425 struct xfs_btree_cur *cur)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426{
Christoph Hellwig8186e512008-10-30 16:54:22 +1100427 struct xfs_ifork *ifp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
Christoph Hellwig8186e512008-10-30 16:54:22 +1100429 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
430 return (struct xfs_btree_block *)ifp->if_broot;
431}
432
433/*
434 * Retrieve the block pointer from the cursor at the given level.
435 * This may be an inode btree root or from a buffer.
436 */
437STATIC struct xfs_btree_block * /* generic btree block pointer */
438xfs_btree_get_block(
439 struct xfs_btree_cur *cur, /* btree cursor */
440 int level, /* level in btree */
441 struct xfs_buf **bpp) /* buffer containing the block */
442{
443 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
444 (level == cur->bc_nlevels - 1)) {
445 *bpp = NULL;
446 return xfs_btree_get_iroot(cur);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 }
Christoph Hellwig8186e512008-10-30 16:54:22 +1100448
449 *bpp = cur->bc_bufs[level];
450 return XFS_BUF_TO_BLOCK(*bpp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451}
452
453/*
454 * Get a buffer for the block, return it with no data read.
455 * Long-form addressing.
456 */
457xfs_buf_t * /* buffer for fsbno */
458xfs_btree_get_bufl(
459 xfs_mount_t *mp, /* file system mount point */
460 xfs_trans_t *tp, /* transaction pointer */
461 xfs_fsblock_t fsbno, /* file system block number */
462 uint lock) /* lock flags for get_buf */
463{
464 xfs_buf_t *bp; /* buffer pointer (return value) */
465 xfs_daddr_t d; /* real disk block address */
466
467 ASSERT(fsbno != NULLFSBLOCK);
468 d = XFS_FSB_TO_DADDR(mp, fsbno);
469 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
470 ASSERT(bp);
471 ASSERT(!XFS_BUF_GETERROR(bp));
472 return bp;
473}
474
475/*
476 * Get a buffer for the block, return it with no data read.
477 * Short-form addressing.
478 */
479xfs_buf_t * /* buffer for agno/agbno */
480xfs_btree_get_bufs(
481 xfs_mount_t *mp, /* file system mount point */
482 xfs_trans_t *tp, /* transaction pointer */
483 xfs_agnumber_t agno, /* allocation group number */
484 xfs_agblock_t agbno, /* allocation group block number */
485 uint lock) /* lock flags for get_buf */
486{
487 xfs_buf_t *bp; /* buffer pointer (return value) */
488 xfs_daddr_t d; /* real disk block address */
489
490 ASSERT(agno != NULLAGNUMBER);
491 ASSERT(agbno != NULLAGBLOCK);
492 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
493 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
494 ASSERT(bp);
495 ASSERT(!XFS_BUF_GETERROR(bp));
496 return bp;
497}
498
499/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 * Check for the cursor referring to the last block at the given level.
501 */
502int /* 1=is last block, 0=not last block */
503xfs_btree_islastblock(
504 xfs_btree_cur_t *cur, /* btree cursor */
505 int level) /* level to check */
506{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100507 struct xfs_btree_block *block; /* generic btree block pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 xfs_buf_t *bp; /* buffer containing block */
509
510 block = xfs_btree_get_block(cur, level, &bp);
511 xfs_btree_check_block(cur, block, level, bp);
Christoph Hellwige99ab902008-10-30 16:54:33 +1100512 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200513 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 else
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200515 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516}
517
518/*
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000519 * Change the cursor to point to the first record at the given level.
520 * Other levels are unaffected.
521 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100522STATIC int /* success=1, failure=0 */
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000523xfs_btree_firstrec(
524 xfs_btree_cur_t *cur, /* btree cursor */
525 int level) /* level to change */
526{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100527 struct xfs_btree_block *block; /* generic btree block pointer */
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000528 xfs_buf_t *bp; /* buffer containing block */
529
530 /*
531 * Get the block pointer for this level.
532 */
533 block = xfs_btree_get_block(cur, level, &bp);
534 xfs_btree_check_block(cur, block, level, bp);
535 /*
536 * It's empty, there is no such record.
537 */
Christoph Hellwigf2277f02008-10-30 16:53:47 +1100538 if (!block->bb_numrecs)
Christoph Hellwigcdcf43332008-08-13 16:23:50 +1000539 return 0;
540 /*
541 * Set the ptr value to 1, that's the first record/key.
542 */
543 cur->bc_ptrs[level] = 1;
544 return 1;
545}
546
547/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 * Change the cursor to point to the last record in the current block
549 * at the given level. Other levels are unaffected.
550 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100551STATIC int /* success=1, failure=0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552xfs_btree_lastrec(
553 xfs_btree_cur_t *cur, /* btree cursor */
554 int level) /* level to change */
555{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100556 struct xfs_btree_block *block; /* generic btree block pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 xfs_buf_t *bp; /* buffer containing block */
558
559 /*
560 * Get the block pointer for this level.
561 */
562 block = xfs_btree_get_block(cur, level, &bp);
563 xfs_btree_check_block(cur, block, level, bp);
564 /*
565 * It's empty, there is no such record.
566 */
Christoph Hellwigf2277f02008-10-30 16:53:47 +1100567 if (!block->bb_numrecs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 return 0;
569 /*
570 * Set the ptr value to numrecs, that's the last record/key.
571 */
Christoph Hellwigf2277f02008-10-30 16:53:47 +1100572 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 return 1;
574}
575
576/*
577 * Compute first and last byte offsets for the fields given.
578 * Interprets the offsets table, which contains struct field offsets.
579 */
580void
581xfs_btree_offsets(
582 __int64_t fields, /* bitmask of fields */
583 const short *offsets, /* table of field offsets */
584 int nbits, /* number of bits to inspect */
585 int *first, /* output: first byte offset */
586 int *last) /* output: last byte offset */
587{
588 int i; /* current bit number */
589 __int64_t imask; /* mask for current bit number */
590
591 ASSERT(fields != 0);
592 /*
593 * Find the lowest bit, so the first byte offset.
594 */
595 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
596 if (imask & fields) {
597 *first = offsets[i];
598 break;
599 }
600 }
601 /*
602 * Find the highest bit, so the last byte offset.
603 */
604 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
605 if (imask & fields) {
606 *last = offsets[i + 1] - 1;
607 break;
608 }
609 }
610}
611
612/*
613 * Get a buffer for the block, return it read in.
614 * Long-form addressing.
615 */
616int /* error */
617xfs_btree_read_bufl(
618 xfs_mount_t *mp, /* file system mount point */
619 xfs_trans_t *tp, /* transaction pointer */
620 xfs_fsblock_t fsbno, /* file system block number */
621 uint lock, /* lock flags for read_buf */
622 xfs_buf_t **bpp, /* buffer for fsbno */
623 int refval) /* ref count value for buffer */
624{
625 xfs_buf_t *bp; /* return value */
626 xfs_daddr_t d; /* real disk block address */
627 int error;
628
629 ASSERT(fsbno != NULLFSBLOCK);
630 d = XFS_FSB_TO_DADDR(mp, fsbno);
631 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
632 mp->m_bsize, lock, &bp))) {
633 return error;
634 }
635 ASSERT(!bp || !XFS_BUF_GETERROR(bp));
Dave Chinner821eb212010-12-02 16:31:13 +1100636 if (bp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 *bpp = bp;
639 return 0;
640}
641
642/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 * Read-ahead the block, don't wait for it, don't return a buffer.
644 * Long-form addressing.
645 */
646/* ARGSUSED */
647void
648xfs_btree_reada_bufl(
649 xfs_mount_t *mp, /* file system mount point */
650 xfs_fsblock_t fsbno, /* file system block number */
651 xfs_extlen_t count) /* count of filesystem blocks */
652{
653 xfs_daddr_t d;
654
655 ASSERT(fsbno != NULLFSBLOCK);
656 d = XFS_FSB_TO_DADDR(mp, fsbno);
Christoph Hellwig1a1a3e92010-10-06 18:41:18 +0000657 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658}
659
660/*
661 * Read-ahead the block, don't wait for it, don't return a buffer.
662 * Short-form addressing.
663 */
664/* ARGSUSED */
665void
666xfs_btree_reada_bufs(
667 xfs_mount_t *mp, /* file system mount point */
668 xfs_agnumber_t agno, /* allocation group number */
669 xfs_agblock_t agbno, /* allocation group block number */
670 xfs_extlen_t count) /* count of filesystem blocks */
671{
672 xfs_daddr_t d;
673
674 ASSERT(agno != NULLAGNUMBER);
675 ASSERT(agbno != NULLAGBLOCK);
676 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
Christoph Hellwig1a1a3e92010-10-06 18:41:18 +0000677 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678}
679
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100680STATIC int
681xfs_btree_readahead_lblock(
682 struct xfs_btree_cur *cur,
683 int lr,
684 struct xfs_btree_block *block)
685{
686 int rval = 0;
Christoph Hellwige6edbd12009-01-08 13:42:23 -0500687 xfs_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
688 xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100689
690 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
691 xfs_btree_reada_bufl(cur->bc_mp, left, 1);
692 rval++;
693 }
694
695 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
696 xfs_btree_reada_bufl(cur->bc_mp, right, 1);
697 rval++;
698 }
699
700 return rval;
701}
702
703STATIC int
704xfs_btree_readahead_sblock(
705 struct xfs_btree_cur *cur,
706 int lr,
707 struct xfs_btree_block *block)
708{
709 int rval = 0;
710 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
711 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
712
713
714 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
715 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
716 left, 1);
717 rval++;
718 }
719
720 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
721 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
722 right, 1);
723 rval++;
724 }
725
726 return rval;
727}
728
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729/*
730 * Read-ahead btree blocks, at the given level.
731 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
732 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +1100733STATIC int
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100734xfs_btree_readahead(
735 struct xfs_btree_cur *cur, /* btree cursor */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 int lev, /* level in btree */
737 int lr) /* left/right bits */
738{
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100739 struct xfs_btree_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100741 /*
742 * No readahead needed if we are at the root level and the
743 * btree root is stored in the inode.
744 */
745 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
746 (lev == cur->bc_nlevels - 1))
747 return 0;
748
749 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
750 return 0;
751
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 cur->bc_ra[lev] |= lr;
Christoph Hellwigb524bfe2008-10-30 16:54:43 +1100753 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
754
755 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
756 return xfs_btree_readahead_lblock(cur, lr, block);
757 return xfs_btree_readahead_sblock(cur, lr, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758}
759
760/*
761 * Set the buffer for level "lev" in the cursor to bp, releasing
762 * any previous buffer.
763 */
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000764STATIC void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765xfs_btree_setbuf(
766 xfs_btree_cur_t *cur, /* btree cursor */
767 int lev, /* level in btree */
768 xfs_buf_t *bp) /* new buffer to set */
769{
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100770 struct xfs_btree_block *b; /* btree block */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000772 if (cur->bc_bufs[lev])
773 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 cur->bc_bufs[lev] = bp;
775 cur->bc_ra[lev] = 0;
Christoph Hellwigc0e59e12010-09-07 23:34:07 +0000776
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 b = XFS_BUF_TO_BLOCK(bp);
Christoph Hellwige99ab902008-10-30 16:54:33 +1100778 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200779 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200781 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
783 } else {
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200784 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200786 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
788 }
789}
Christoph Hellwig637aa502008-10-30 16:55:45 +1100790
791STATIC int
792xfs_btree_ptr_is_null(
793 struct xfs_btree_cur *cur,
794 union xfs_btree_ptr *ptr)
795{
796 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200797 return ptr->l == cpu_to_be64(NULLDFSBNO);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100798 else
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200799 return ptr->s == cpu_to_be32(NULLAGBLOCK);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100800}
801
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100802STATIC void
803xfs_btree_set_ptr_null(
804 struct xfs_btree_cur *cur,
805 union xfs_btree_ptr *ptr)
806{
807 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
Dave Chinner33ad9652009-01-21 15:22:17 +1100808 ptr->l = cpu_to_be64(NULLDFSBNO);
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100809 else
810 ptr->s = cpu_to_be32(NULLAGBLOCK);
811}
812
Christoph Hellwig637aa502008-10-30 16:55:45 +1100813/*
814 * Get/set/init sibling pointers
815 */
816STATIC void
817xfs_btree_get_sibling(
818 struct xfs_btree_cur *cur,
819 struct xfs_btree_block *block,
820 union xfs_btree_ptr *ptr,
821 int lr)
822{
823 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
824
825 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
826 if (lr == XFS_BB_RIGHTSIB)
827 ptr->l = block->bb_u.l.bb_rightsib;
828 else
829 ptr->l = block->bb_u.l.bb_leftsib;
830 } else {
831 if (lr == XFS_BB_RIGHTSIB)
832 ptr->s = block->bb_u.s.bb_rightsib;
833 else
834 ptr->s = block->bb_u.s.bb_leftsib;
835 }
836}
837
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100838STATIC void
839xfs_btree_set_sibling(
840 struct xfs_btree_cur *cur,
841 struct xfs_btree_block *block,
842 union xfs_btree_ptr *ptr,
843 int lr)
844{
845 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
846
847 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
848 if (lr == XFS_BB_RIGHTSIB)
849 block->bb_u.l.bb_rightsib = ptr->l;
850 else
851 block->bb_u.l.bb_leftsib = ptr->l;
852 } else {
853 if (lr == XFS_BB_RIGHTSIB)
854 block->bb_u.s.bb_rightsib = ptr->s;
855 else
856 block->bb_u.s.bb_leftsib = ptr->s;
857 }
858}
859
860STATIC void
861xfs_btree_init_block(
862 struct xfs_btree_cur *cur,
863 int level,
864 int numrecs,
865 struct xfs_btree_block *new) /* new block */
866{
867 new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
868 new->bb_level = cpu_to_be16(level);
869 new->bb_numrecs = cpu_to_be16(numrecs);
870
871 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
Dave Chinner33ad9652009-01-21 15:22:17 +1100872 new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
873 new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100874 } else {
875 new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
876 new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
877 }
878}
879
Christoph Hellwig278d0ca2008-10-30 16:56:32 +1100880/*
881 * Return true if ptr is the last record in the btree and
882 * we need to track updateѕ to this record. The decision
883 * will be further refined in the update_lastrec method.
884 */
885STATIC int
886xfs_btree_is_lastrec(
887 struct xfs_btree_cur *cur,
888 struct xfs_btree_block *block,
889 int level)
890{
891 union xfs_btree_ptr ptr;
892
893 if (level > 0)
894 return 0;
895 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
896 return 0;
897
898 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
899 if (!xfs_btree_ptr_is_null(cur, &ptr))
900 return 0;
901 return 1;
902}
903
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100904STATIC void
905xfs_btree_buf_to_ptr(
906 struct xfs_btree_cur *cur,
907 struct xfs_buf *bp,
908 union xfs_btree_ptr *ptr)
909{
910 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
911 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
912 XFS_BUF_ADDR(bp)));
913 else {
Eric Sandeen9d87c312009-01-14 23:22:07 -0600914 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100915 XFS_BUF_ADDR(bp)));
916 }
917}
918
Christoph Hellwig637aa502008-10-30 16:55:45 +1100919STATIC xfs_daddr_t
920xfs_btree_ptr_to_daddr(
921 struct xfs_btree_cur *cur,
922 union xfs_btree_ptr *ptr)
923{
924 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200925 ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO));
Christoph Hellwig637aa502008-10-30 16:55:45 +1100926
927 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
928 } else {
929 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
Christoph Hellwig69ef9212011-07-08 14:36:05 +0200930 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
Christoph Hellwig637aa502008-10-30 16:55:45 +1100931
932 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
933 be32_to_cpu(ptr->s));
934 }
935}
936
937STATIC void
938xfs_btree_set_refs(
939 struct xfs_btree_cur *cur,
940 struct xfs_buf *bp)
941{
942 switch (cur->bc_btnum) {
943 case XFS_BTNUM_BNO:
944 case XFS_BTNUM_CNT:
Dave Chinner821eb212010-12-02 16:31:13 +1100945 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_ALLOC_BTREE_REF);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100946 break;
947 case XFS_BTNUM_INO:
Dave Chinner821eb212010-12-02 16:31:13 +1100948 XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, XFS_INO_BTREE_REF);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100949 break;
950 case XFS_BTNUM_BMAP:
Dave Chinner821eb212010-12-02 16:31:13 +1100951 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_BMAP_BTREE_REF);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100952 break;
953 default:
954 ASSERT(0);
955 }
956}
957
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100958STATIC int
959xfs_btree_get_buf_block(
960 struct xfs_btree_cur *cur,
961 union xfs_btree_ptr *ptr,
962 int flags,
963 struct xfs_btree_block **block,
964 struct xfs_buf **bpp)
965{
966 struct xfs_mount *mp = cur->bc_mp;
967 xfs_daddr_t d;
968
969 /* need to sort out how callers deal with failures first */
Christoph Hellwig0cadda12010-01-19 09:56:44 +0000970 ASSERT(!(flags & XBF_TRYLOCK));
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +1100971
972 d = xfs_btree_ptr_to_daddr(cur, ptr);
973 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
974 mp->m_bsize, flags);
975
976 ASSERT(*bpp);
977 ASSERT(!XFS_BUF_GETERROR(*bpp));
978
979 *block = XFS_BUF_TO_BLOCK(*bpp);
980 return 0;
981}
982
Christoph Hellwig637aa502008-10-30 16:55:45 +1100983/*
984 * Read in the buffer at the given ptr and return the buffer and
985 * the block pointer within the buffer.
986 */
987STATIC int
988xfs_btree_read_buf_block(
989 struct xfs_btree_cur *cur,
990 union xfs_btree_ptr *ptr,
991 int level,
992 int flags,
993 struct xfs_btree_block **block,
994 struct xfs_buf **bpp)
995{
996 struct xfs_mount *mp = cur->bc_mp;
997 xfs_daddr_t d;
998 int error;
999
1000 /* need to sort out how callers deal with failures first */
Christoph Hellwig0cadda12010-01-19 09:56:44 +00001001 ASSERT(!(flags & XBF_TRYLOCK));
Christoph Hellwig637aa502008-10-30 16:55:45 +11001002
1003 d = xfs_btree_ptr_to_daddr(cur, ptr);
1004 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1005 mp->m_bsize, flags, bpp);
1006 if (error)
1007 return error;
1008
1009 ASSERT(*bpp != NULL);
1010 ASSERT(!XFS_BUF_GETERROR(*bpp));
1011
1012 xfs_btree_set_refs(cur, *bpp);
1013 *block = XFS_BUF_TO_BLOCK(*bpp);
1014
1015 error = xfs_btree_check_block(cur, *block, level, *bpp);
1016 if (error)
1017 xfs_trans_brelse(cur->bc_tp, *bpp);
1018 return error;
1019}
1020
1021/*
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001022 * Copy keys from one btree block to another.
1023 */
1024STATIC void
1025xfs_btree_copy_keys(
1026 struct xfs_btree_cur *cur,
1027 union xfs_btree_key *dst_key,
1028 union xfs_btree_key *src_key,
1029 int numkeys)
1030{
1031 ASSERT(numkeys >= 0);
1032 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1033}
1034
1035/*
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001036 * Copy records from one btree block to another.
1037 */
1038STATIC void
1039xfs_btree_copy_recs(
1040 struct xfs_btree_cur *cur,
1041 union xfs_btree_rec *dst_rec,
1042 union xfs_btree_rec *src_rec,
1043 int numrecs)
1044{
1045 ASSERT(numrecs >= 0);
1046 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1047}
1048
1049/*
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001050 * Copy block pointers from one btree block to another.
1051 */
1052STATIC void
1053xfs_btree_copy_ptrs(
1054 struct xfs_btree_cur *cur,
1055 union xfs_btree_ptr *dst_ptr,
1056 union xfs_btree_ptr *src_ptr,
1057 int numptrs)
1058{
1059 ASSERT(numptrs >= 0);
1060 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1061}
1062
1063/*
1064 * Shift keys one index left/right inside a single btree block.
1065 */
1066STATIC void
1067xfs_btree_shift_keys(
1068 struct xfs_btree_cur *cur,
1069 union xfs_btree_key *key,
1070 int dir,
1071 int numkeys)
1072{
1073 char *dst_key;
1074
1075 ASSERT(numkeys >= 0);
1076 ASSERT(dir == 1 || dir == -1);
1077
1078 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1079 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1080}
1081
1082/*
1083 * Shift records one index left/right inside a single btree block.
1084 */
1085STATIC void
1086xfs_btree_shift_recs(
1087 struct xfs_btree_cur *cur,
1088 union xfs_btree_rec *rec,
1089 int dir,
1090 int numrecs)
1091{
1092 char *dst_rec;
1093
1094 ASSERT(numrecs >= 0);
1095 ASSERT(dir == 1 || dir == -1);
1096
1097 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1098 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1099}
1100
1101/*
1102 * Shift block pointers one index left/right inside a single btree block.
1103 */
1104STATIC void
1105xfs_btree_shift_ptrs(
1106 struct xfs_btree_cur *cur,
1107 union xfs_btree_ptr *ptr,
1108 int dir,
1109 int numptrs)
1110{
1111 char *dst_ptr;
1112
1113 ASSERT(numptrs >= 0);
1114 ASSERT(dir == 1 || dir == -1);
1115
1116 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1117 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1118}
1119
1120/*
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001121 * Log key values from the btree block.
1122 */
1123STATIC void
1124xfs_btree_log_keys(
1125 struct xfs_btree_cur *cur,
1126 struct xfs_buf *bp,
1127 int first,
1128 int last)
1129{
1130 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1131 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1132
1133 if (bp) {
1134 xfs_trans_log_buf(cur->bc_tp, bp,
1135 xfs_btree_key_offset(cur, first),
1136 xfs_btree_key_offset(cur, last + 1) - 1);
1137 } else {
1138 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1139 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1140 }
1141
1142 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1143}
1144
1145/*
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001146 * Log record values from the btree block.
1147 */
Christoph Hellwigfd6bcc5b2008-10-30 16:58:21 +11001148void
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001149xfs_btree_log_recs(
1150 struct xfs_btree_cur *cur,
1151 struct xfs_buf *bp,
1152 int first,
1153 int last)
1154{
1155 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1156 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1157
1158 xfs_trans_log_buf(cur->bc_tp, bp,
1159 xfs_btree_rec_offset(cur, first),
1160 xfs_btree_rec_offset(cur, last + 1) - 1);
1161
1162 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1163}
1164
1165/*
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001166 * Log block pointer fields from a btree block (nonleaf).
1167 */
1168STATIC void
1169xfs_btree_log_ptrs(
1170 struct xfs_btree_cur *cur, /* btree cursor */
1171 struct xfs_buf *bp, /* buffer containing btree block */
1172 int first, /* index of first pointer to log */
1173 int last) /* index of last pointer to log */
1174{
1175 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1176 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1177
1178 if (bp) {
1179 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1180 int level = xfs_btree_get_level(block);
1181
1182 xfs_trans_log_buf(cur->bc_tp, bp,
1183 xfs_btree_ptr_offset(cur, first, level),
1184 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1185 } else {
1186 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1187 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1188 }
1189
1190 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1191}
1192
1193/*
1194 * Log fields from a btree block header.
1195 */
Christoph Hellwigfd6bcc5b2008-10-30 16:58:21 +11001196void
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001197xfs_btree_log_block(
1198 struct xfs_btree_cur *cur, /* btree cursor */
1199 struct xfs_buf *bp, /* buffer containing btree block */
1200 int fields) /* mask of fields: XFS_BB_... */
1201{
1202 int first; /* first byte offset logged */
1203 int last; /* last byte offset logged */
1204 static const short soffsets[] = { /* table of offsets (short) */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +11001205 offsetof(struct xfs_btree_block, bb_magic),
1206 offsetof(struct xfs_btree_block, bb_level),
1207 offsetof(struct xfs_btree_block, bb_numrecs),
1208 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1209 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1210 XFS_BTREE_SBLOCK_LEN
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001211 };
1212 static const short loffsets[] = { /* table of offsets (long) */
Christoph Hellwig7cc95a82008-10-30 17:14:34 +11001213 offsetof(struct xfs_btree_block, bb_magic),
1214 offsetof(struct xfs_btree_block, bb_level),
1215 offsetof(struct xfs_btree_block, bb_numrecs),
1216 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1217 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1218 XFS_BTREE_LBLOCK_LEN
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001219 };
1220
1221 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1222 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1223
1224 if (bp) {
1225 xfs_btree_offsets(fields,
1226 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1227 loffsets : soffsets,
1228 XFS_BB_NUM_BITS, &first, &last);
1229 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1230 } else {
1231 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1232 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1233 }
1234
1235 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1236}
1237
1238/*
Christoph Hellwig637aa502008-10-30 16:55:45 +11001239 * Increment cursor by one record at the level.
1240 * For nonzero levels the leaf-ward information is untouched.
1241 */
1242int /* error */
1243xfs_btree_increment(
1244 struct xfs_btree_cur *cur,
1245 int level,
1246 int *stat) /* success/failure */
1247{
1248 struct xfs_btree_block *block;
1249 union xfs_btree_ptr ptr;
1250 struct xfs_buf *bp;
1251 int error; /* error return value */
1252 int lev;
1253
1254 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1255 XFS_BTREE_TRACE_ARGI(cur, level);
1256
1257 ASSERT(level < cur->bc_nlevels);
1258
1259 /* Read-ahead to the right at this level. */
1260 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1261
1262 /* Get a pointer to the btree block. */
1263 block = xfs_btree_get_block(cur, level, &bp);
1264
1265#ifdef DEBUG
1266 error = xfs_btree_check_block(cur, block, level, bp);
1267 if (error)
1268 goto error0;
1269#endif
1270
1271 /* We're done if we remain in the block after the increment. */
1272 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1273 goto out1;
1274
1275 /* Fail if we just went off the right edge of the tree. */
1276 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1277 if (xfs_btree_ptr_is_null(cur, &ptr))
1278 goto out0;
1279
1280 XFS_BTREE_STATS_INC(cur, increment);
1281
1282 /*
1283 * March up the tree incrementing pointers.
1284 * Stop when we don't go off the right edge of a block.
1285 */
1286 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1287 block = xfs_btree_get_block(cur, lev, &bp);
1288
1289#ifdef DEBUG
1290 error = xfs_btree_check_block(cur, block, lev, bp);
1291 if (error)
1292 goto error0;
1293#endif
1294
1295 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1296 break;
1297
1298 /* Read-ahead the right block for the next loop. */
1299 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1300 }
1301
1302 /*
1303 * If we went off the root then we are either seriously
1304 * confused or have the tree root in an inode.
1305 */
1306 if (lev == cur->bc_nlevels) {
1307 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1308 goto out0;
1309 ASSERT(0);
1310 error = EFSCORRUPTED;
1311 goto error0;
1312 }
1313 ASSERT(lev < cur->bc_nlevels);
1314
1315 /*
1316 * Now walk back down the tree, fixing up the cursor's buffer
1317 * pointers and key numbers.
1318 */
1319 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1320 union xfs_btree_ptr *ptrp;
1321
1322 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1323 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1324 0, &block, &bp);
1325 if (error)
1326 goto error0;
1327
1328 xfs_btree_setbuf(cur, lev, bp);
1329 cur->bc_ptrs[lev] = 1;
1330 }
1331out1:
1332 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1333 *stat = 1;
1334 return 0;
1335
1336out0:
1337 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1338 *stat = 0;
1339 return 0;
1340
1341error0:
1342 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1343 return error;
1344}
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001345
1346/*
1347 * Decrement cursor by one record at the level.
1348 * For nonzero levels the leaf-ward information is untouched.
1349 */
1350int /* error */
1351xfs_btree_decrement(
1352 struct xfs_btree_cur *cur,
1353 int level,
1354 int *stat) /* success/failure */
1355{
1356 struct xfs_btree_block *block;
1357 xfs_buf_t *bp;
1358 int error; /* error return value */
1359 int lev;
1360 union xfs_btree_ptr ptr;
1361
1362 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1363 XFS_BTREE_TRACE_ARGI(cur, level);
1364
1365 ASSERT(level < cur->bc_nlevels);
1366
1367 /* Read-ahead to the left at this level. */
1368 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1369
1370 /* We're done if we remain in the block after the decrement. */
1371 if (--cur->bc_ptrs[level] > 0)
1372 goto out1;
1373
1374 /* Get a pointer to the btree block. */
1375 block = xfs_btree_get_block(cur, level, &bp);
1376
1377#ifdef DEBUG
1378 error = xfs_btree_check_block(cur, block, level, bp);
1379 if (error)
1380 goto error0;
1381#endif
1382
1383 /* Fail if we just went off the left edge of the tree. */
1384 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1385 if (xfs_btree_ptr_is_null(cur, &ptr))
1386 goto out0;
1387
1388 XFS_BTREE_STATS_INC(cur, decrement);
1389
1390 /*
1391 * March up the tree decrementing pointers.
1392 * Stop when we don't go off the left edge of a block.
1393 */
1394 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1395 if (--cur->bc_ptrs[lev] > 0)
1396 break;
1397 /* Read-ahead the left block for the next loop. */
1398 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1399 }
1400
1401 /*
1402 * If we went off the root then we are seriously confused.
1403 * or the root of the tree is in an inode.
1404 */
1405 if (lev == cur->bc_nlevels) {
1406 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1407 goto out0;
1408 ASSERT(0);
1409 error = EFSCORRUPTED;
1410 goto error0;
1411 }
1412 ASSERT(lev < cur->bc_nlevels);
1413
1414 /*
1415 * Now walk back down the tree, fixing up the cursor's buffer
1416 * pointers and key numbers.
1417 */
1418 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1419 union xfs_btree_ptr *ptrp;
1420
1421 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1422 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1423 0, &block, &bp);
1424 if (error)
1425 goto error0;
1426 xfs_btree_setbuf(cur, lev, bp);
1427 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1428 }
1429out1:
1430 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1431 *stat = 1;
1432 return 0;
1433
1434out0:
1435 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1436 *stat = 0;
1437 return 0;
1438
1439error0:
1440 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1441 return error;
1442}
1443
Christoph Hellwigfe033cc2008-10-30 16:56:09 +11001444STATIC int
1445xfs_btree_lookup_get_block(
1446 struct xfs_btree_cur *cur, /* btree cursor */
1447 int level, /* level in the btree */
1448 union xfs_btree_ptr *pp, /* ptr to btree block */
1449 struct xfs_btree_block **blkp) /* return btree block */
1450{
1451 struct xfs_buf *bp; /* buffer pointer for btree block */
1452 int error = 0;
1453
1454 /* special case the root block if in an inode */
1455 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1456 (level == cur->bc_nlevels - 1)) {
1457 *blkp = xfs_btree_get_iroot(cur);
1458 return 0;
1459 }
1460
1461 /*
1462 * If the old buffer at this level for the disk address we are
1463 * looking for re-use it.
1464 *
1465 * Otherwise throw it away and get a new one.
1466 */
1467 bp = cur->bc_bufs[level];
1468 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1469 *blkp = XFS_BUF_TO_BLOCK(bp);
1470 return 0;
1471 }
1472
1473 error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1474 if (error)
1475 return error;
1476
1477 xfs_btree_setbuf(cur, level, bp);
1478 return 0;
1479}
1480
1481/*
1482 * Get current search key. For level 0 we don't actually have a key
1483 * structure so we make one up from the record. For all other levels
1484 * we just return the right key.
1485 */
1486STATIC union xfs_btree_key *
1487xfs_lookup_get_search_key(
1488 struct xfs_btree_cur *cur,
1489 int level,
1490 int keyno,
1491 struct xfs_btree_block *block,
1492 union xfs_btree_key *kp)
1493{
1494 if (level == 0) {
1495 cur->bc_ops->init_key_from_rec(kp,
1496 xfs_btree_rec_addr(cur, keyno, block));
1497 return kp;
1498 }
1499
1500 return xfs_btree_key_addr(cur, keyno, block);
1501}
1502
1503/*
1504 * Lookup the record. The cursor is made to point to it, based on dir.
1505 * Return 0 if can't find any such record, 1 for success.
1506 */
1507int /* error */
1508xfs_btree_lookup(
1509 struct xfs_btree_cur *cur, /* btree cursor */
1510 xfs_lookup_t dir, /* <=, ==, or >= */
1511 int *stat) /* success/failure */
1512{
1513 struct xfs_btree_block *block; /* current btree block */
1514 __int64_t diff; /* difference for the current key */
1515 int error; /* error return value */
1516 int keyno; /* current key number */
1517 int level; /* level in the btree */
1518 union xfs_btree_ptr *pp; /* ptr to btree block */
1519 union xfs_btree_ptr ptr; /* ptr to btree block */
1520
1521 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1522 XFS_BTREE_TRACE_ARGI(cur, dir);
1523
1524 XFS_BTREE_STATS_INC(cur, lookup);
1525
1526 block = NULL;
1527 keyno = 0;
1528
1529 /* initialise start pointer from cursor */
1530 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1531 pp = &ptr;
1532
1533 /*
1534 * Iterate over each level in the btree, starting at the root.
1535 * For each level above the leaves, find the key we need, based
1536 * on the lookup record, then follow the corresponding block
1537 * pointer down to the next level.
1538 */
1539 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1540 /* Get the block we need to do the lookup on. */
1541 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1542 if (error)
1543 goto error0;
1544
1545 if (diff == 0) {
1546 /*
1547 * If we already had a key match at a higher level, we
1548 * know we need to use the first entry in this block.
1549 */
1550 keyno = 1;
1551 } else {
1552 /* Otherwise search this block. Do a binary search. */
1553
1554 int high; /* high entry number */
1555 int low; /* low entry number */
1556
1557 /* Set low and high entry numbers, 1-based. */
1558 low = 1;
1559 high = xfs_btree_get_numrecs(block);
1560 if (!high) {
1561 /* Block is empty, must be an empty leaf. */
1562 ASSERT(level == 0 && cur->bc_nlevels == 1);
1563
1564 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1565 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1566 *stat = 0;
1567 return 0;
1568 }
1569
1570 /* Binary search the block. */
1571 while (low <= high) {
1572 union xfs_btree_key key;
1573 union xfs_btree_key *kp;
1574
1575 XFS_BTREE_STATS_INC(cur, compare);
1576
1577 /* keyno is average of low and high. */
1578 keyno = (low + high) >> 1;
1579
1580 /* Get current search key */
1581 kp = xfs_lookup_get_search_key(cur, level,
1582 keyno, block, &key);
1583
1584 /*
1585 * Compute difference to get next direction:
1586 * - less than, move right
1587 * - greater than, move left
1588 * - equal, we're done
1589 */
1590 diff = cur->bc_ops->key_diff(cur, kp);
1591 if (diff < 0)
1592 low = keyno + 1;
1593 else if (diff > 0)
1594 high = keyno - 1;
1595 else
1596 break;
1597 }
1598 }
1599
1600 /*
1601 * If there are more levels, set up for the next level
1602 * by getting the block number and filling in the cursor.
1603 */
1604 if (level > 0) {
1605 /*
1606 * If we moved left, need the previous key number,
1607 * unless there isn't one.
1608 */
1609 if (diff > 0 && --keyno < 1)
1610 keyno = 1;
1611 pp = xfs_btree_ptr_addr(cur, keyno, block);
1612
1613#ifdef DEBUG
1614 error = xfs_btree_check_ptr(cur, pp, 0, level);
1615 if (error)
1616 goto error0;
1617#endif
1618 cur->bc_ptrs[level] = keyno;
1619 }
1620 }
1621
1622 /* Done with the search. See if we need to adjust the results. */
1623 if (dir != XFS_LOOKUP_LE && diff < 0) {
1624 keyno++;
1625 /*
1626 * If ge search and we went off the end of the block, but it's
1627 * not the last block, we're in the wrong block.
1628 */
1629 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1630 if (dir == XFS_LOOKUP_GE &&
1631 keyno > xfs_btree_get_numrecs(block) &&
1632 !xfs_btree_ptr_is_null(cur, &ptr)) {
1633 int i;
1634
1635 cur->bc_ptrs[0] = keyno;
1636 error = xfs_btree_increment(cur, 0, &i);
1637 if (error)
1638 goto error0;
1639 XFS_WANT_CORRUPTED_RETURN(i == 1);
1640 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1641 *stat = 1;
1642 return 0;
1643 }
1644 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1645 keyno--;
1646 cur->bc_ptrs[0] = keyno;
1647
1648 /* Return if we succeeded or not. */
1649 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1650 *stat = 0;
1651 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1652 *stat = 1;
1653 else
1654 *stat = 0;
1655 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1656 return 0;
1657
1658error0:
1659 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1660 return error;
1661}
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001662
1663/*
1664 * Update keys at all levels from here to the root along the cursor's path.
1665 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11001666STATIC int
Christoph Hellwig38bb7422008-10-30 16:56:22 +11001667xfs_btree_updkey(
1668 struct xfs_btree_cur *cur,
1669 union xfs_btree_key *keyp,
1670 int level)
1671{
1672 struct xfs_btree_block *block;
1673 struct xfs_buf *bp;
1674 union xfs_btree_key *kp;
1675 int ptr;
1676
1677 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1678 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1679
1680 ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1681
1682 /*
1683 * Go up the tree from this level toward the root.
1684 * At each level, update the key value to the value input.
1685 * Stop when we reach a level where the cursor isn't pointing
1686 * at the first entry in the block.
1687 */
1688 for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1689#ifdef DEBUG
1690 int error;
1691#endif
1692 block = xfs_btree_get_block(cur, level, &bp);
1693#ifdef DEBUG
1694 error = xfs_btree_check_block(cur, block, level, bp);
1695 if (error) {
1696 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1697 return error;
1698 }
1699#endif
1700 ptr = cur->bc_ptrs[level];
1701 kp = xfs_btree_key_addr(cur, ptr, block);
1702 xfs_btree_copy_keys(cur, kp, keyp, 1);
1703 xfs_btree_log_keys(cur, bp, ptr, ptr);
1704 }
1705
1706 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1707 return 0;
1708}
Christoph Hellwig278d0ca2008-10-30 16:56:32 +11001709
1710/*
1711 * Update the record referred to by cur to the value in the
1712 * given record. This either works (return 0) or gets an
1713 * EFSCORRUPTED error.
1714 */
1715int
1716xfs_btree_update(
1717 struct xfs_btree_cur *cur,
1718 union xfs_btree_rec *rec)
1719{
1720 struct xfs_btree_block *block;
1721 struct xfs_buf *bp;
1722 int error;
1723 int ptr;
1724 union xfs_btree_rec *rp;
1725
1726 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1727 XFS_BTREE_TRACE_ARGR(cur, rec);
1728
1729 /* Pick up the current block. */
1730 block = xfs_btree_get_block(cur, 0, &bp);
1731
1732#ifdef DEBUG
1733 error = xfs_btree_check_block(cur, block, 0, bp);
1734 if (error)
1735 goto error0;
1736#endif
1737 /* Get the address of the rec to be updated. */
1738 ptr = cur->bc_ptrs[0];
1739 rp = xfs_btree_rec_addr(cur, ptr, block);
1740
1741 /* Fill in the new contents and log them. */
1742 xfs_btree_copy_recs(cur, rp, rec, 1);
1743 xfs_btree_log_recs(cur, bp, ptr, ptr);
1744
1745 /*
1746 * If we are tracking the last record in the tree and
1747 * we are at the far right edge of the tree, update it.
1748 */
1749 if (xfs_btree_is_lastrec(cur, block, 0)) {
1750 cur->bc_ops->update_lastrec(cur, block, rec,
1751 ptr, LASTREC_UPDATE);
1752 }
1753
1754 /* Updating first rec in leaf. Pass new key value up to our parent. */
1755 if (ptr == 1) {
1756 union xfs_btree_key key;
1757
1758 cur->bc_ops->init_key_from_rec(&key, rec);
1759 error = xfs_btree_updkey(cur, &key, 1);
1760 if (error)
1761 goto error0;
1762 }
1763
1764 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1765 return 0;
1766
1767error0:
1768 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1769 return error;
1770}
1771
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001772/*
Christoph Hellwig687b8902008-10-30 16:56:53 +11001773 * Move 1 record left from cur/level if possible.
1774 * Update cur to reflect the new path.
1775 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11001776STATIC int /* error */
Christoph Hellwig687b8902008-10-30 16:56:53 +11001777xfs_btree_lshift(
1778 struct xfs_btree_cur *cur,
1779 int level,
1780 int *stat) /* success/failure */
1781{
1782 union xfs_btree_key key; /* btree key */
1783 struct xfs_buf *lbp; /* left buffer pointer */
1784 struct xfs_btree_block *left; /* left btree block */
1785 int lrecs; /* left record count */
1786 struct xfs_buf *rbp; /* right buffer pointer */
1787 struct xfs_btree_block *right; /* right btree block */
1788 int rrecs; /* right record count */
1789 union xfs_btree_ptr lptr; /* left btree pointer */
1790 union xfs_btree_key *rkp = NULL; /* right btree key */
1791 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
1792 union xfs_btree_rec *rrp = NULL; /* right record pointer */
1793 int error; /* error return value */
1794
1795 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1796 XFS_BTREE_TRACE_ARGI(cur, level);
1797
1798 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1799 level == cur->bc_nlevels - 1)
1800 goto out0;
1801
1802 /* Set up variables for this block as "right". */
1803 right = xfs_btree_get_block(cur, level, &rbp);
1804
1805#ifdef DEBUG
1806 error = xfs_btree_check_block(cur, right, level, rbp);
1807 if (error)
1808 goto error0;
1809#endif
1810
1811 /* If we've got no left sibling then we can't shift an entry left. */
1812 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1813 if (xfs_btree_ptr_is_null(cur, &lptr))
1814 goto out0;
1815
1816 /*
1817 * If the cursor entry is the one that would be moved, don't
1818 * do it... it's too complicated.
1819 */
1820 if (cur->bc_ptrs[level] <= 1)
1821 goto out0;
1822
1823 /* Set up the left neighbor as "left". */
1824 error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
1825 if (error)
1826 goto error0;
1827
1828 /* If it's full, it can't take another entry. */
1829 lrecs = xfs_btree_get_numrecs(left);
1830 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
1831 goto out0;
1832
1833 rrecs = xfs_btree_get_numrecs(right);
1834
1835 /*
1836 * We add one entry to the left side and remove one for the right side.
Malcolm Parsons9da096f2009-03-29 09:55:42 +02001837 * Account for it here, the changes will be updated on disk and logged
Christoph Hellwig687b8902008-10-30 16:56:53 +11001838 * later.
1839 */
1840 lrecs++;
1841 rrecs--;
1842
1843 XFS_BTREE_STATS_INC(cur, lshift);
1844 XFS_BTREE_STATS_ADD(cur, moves, 1);
1845
1846 /*
1847 * If non-leaf, copy a key and a ptr to the left block.
1848 * Log the changes to the left block.
1849 */
1850 if (level > 0) {
1851 /* It's a non-leaf. Move keys and pointers. */
1852 union xfs_btree_key *lkp; /* left btree key */
1853 union xfs_btree_ptr *lpp; /* left address pointer */
1854
1855 lkp = xfs_btree_key_addr(cur, lrecs, left);
1856 rkp = xfs_btree_key_addr(cur, 1, right);
1857
1858 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
1859 rpp = xfs_btree_ptr_addr(cur, 1, right);
1860#ifdef DEBUG
1861 error = xfs_btree_check_ptr(cur, rpp, 0, level);
1862 if (error)
1863 goto error0;
1864#endif
1865 xfs_btree_copy_keys(cur, lkp, rkp, 1);
1866 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
1867
1868 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
1869 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
1870
Christoph Hellwig4a26e662008-10-30 16:58:32 +11001871 ASSERT(cur->bc_ops->keys_inorder(cur,
1872 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
Christoph Hellwig687b8902008-10-30 16:56:53 +11001873 } else {
1874 /* It's a leaf. Move records. */
1875 union xfs_btree_rec *lrp; /* left record pointer */
1876
1877 lrp = xfs_btree_rec_addr(cur, lrecs, left);
1878 rrp = xfs_btree_rec_addr(cur, 1, right);
1879
1880 xfs_btree_copy_recs(cur, lrp, rrp, 1);
1881 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
1882
Christoph Hellwig4a26e662008-10-30 16:58:32 +11001883 ASSERT(cur->bc_ops->recs_inorder(cur,
1884 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
Christoph Hellwig687b8902008-10-30 16:56:53 +11001885 }
1886
1887 xfs_btree_set_numrecs(left, lrecs);
1888 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
1889
1890 xfs_btree_set_numrecs(right, rrecs);
1891 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
1892
1893 /*
1894 * Slide the contents of right down one entry.
1895 */
1896 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
1897 if (level > 0) {
1898 /* It's a nonleaf. operate on keys and ptrs */
1899#ifdef DEBUG
1900 int i; /* loop index */
1901
1902 for (i = 0; i < rrecs; i++) {
1903 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
1904 if (error)
1905 goto error0;
1906 }
1907#endif
1908 xfs_btree_shift_keys(cur,
1909 xfs_btree_key_addr(cur, 2, right),
1910 -1, rrecs);
1911 xfs_btree_shift_ptrs(cur,
1912 xfs_btree_ptr_addr(cur, 2, right),
1913 -1, rrecs);
1914
1915 xfs_btree_log_keys(cur, rbp, 1, rrecs);
1916 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
1917 } else {
1918 /* It's a leaf. operate on records */
1919 xfs_btree_shift_recs(cur,
1920 xfs_btree_rec_addr(cur, 2, right),
1921 -1, rrecs);
1922 xfs_btree_log_recs(cur, rbp, 1, rrecs);
1923
1924 /*
1925 * If it's the first record in the block, we'll need a key
1926 * structure to pass up to the next level (updkey).
1927 */
1928 cur->bc_ops->init_key_from_rec(&key,
1929 xfs_btree_rec_addr(cur, 1, right));
1930 rkp = &key;
1931 }
1932
1933 /* Update the parent key values of right. */
1934 error = xfs_btree_updkey(cur, rkp, level + 1);
1935 if (error)
1936 goto error0;
1937
1938 /* Slide the cursor value left one. */
1939 cur->bc_ptrs[level]--;
1940
1941 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1942 *stat = 1;
1943 return 0;
1944
1945out0:
1946 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1947 *stat = 0;
1948 return 0;
1949
1950error0:
1951 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1952 return error;
1953}
1954
1955/*
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001956 * Move 1 record right from cur/level if possible.
1957 * Update cur to reflect the new path.
1958 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11001959STATIC int /* error */
Christoph Hellwig9eaead52008-10-30 16:56:43 +11001960xfs_btree_rshift(
1961 struct xfs_btree_cur *cur,
1962 int level,
1963 int *stat) /* success/failure */
1964{
1965 union xfs_btree_key key; /* btree key */
1966 struct xfs_buf *lbp; /* left buffer pointer */
1967 struct xfs_btree_block *left; /* left btree block */
1968 struct xfs_buf *rbp; /* right buffer pointer */
1969 struct xfs_btree_block *right; /* right btree block */
1970 struct xfs_btree_cur *tcur; /* temporary btree cursor */
1971 union xfs_btree_ptr rptr; /* right block pointer */
1972 union xfs_btree_key *rkp; /* right btree key */
1973 int rrecs; /* right record count */
1974 int lrecs; /* left record count */
1975 int error; /* error return value */
1976 int i; /* loop counter */
1977
1978 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1979 XFS_BTREE_TRACE_ARGI(cur, level);
1980
1981 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1982 (level == cur->bc_nlevels - 1))
1983 goto out0;
1984
1985 /* Set up variables for this block as "left". */
1986 left = xfs_btree_get_block(cur, level, &lbp);
1987
1988#ifdef DEBUG
1989 error = xfs_btree_check_block(cur, left, level, lbp);
1990 if (error)
1991 goto error0;
1992#endif
1993
1994 /* If we've got no right sibling then we can't shift an entry right. */
1995 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
1996 if (xfs_btree_ptr_is_null(cur, &rptr))
1997 goto out0;
1998
1999 /*
2000 * If the cursor entry is the one that would be moved, don't
2001 * do it... it's too complicated.
2002 */
2003 lrecs = xfs_btree_get_numrecs(left);
2004 if (cur->bc_ptrs[level] >= lrecs)
2005 goto out0;
2006
2007 /* Set up the right neighbor as "right". */
2008 error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2009 if (error)
2010 goto error0;
2011
2012 /* If it's full, it can't take another entry. */
2013 rrecs = xfs_btree_get_numrecs(right);
2014 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2015 goto out0;
2016
2017 XFS_BTREE_STATS_INC(cur, rshift);
2018 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2019
2020 /*
2021 * Make a hole at the start of the right neighbor block, then
2022 * copy the last left block entry to the hole.
2023 */
2024 if (level > 0) {
2025 /* It's a nonleaf. make a hole in the keys and ptrs */
2026 union xfs_btree_key *lkp;
2027 union xfs_btree_ptr *lpp;
2028 union xfs_btree_ptr *rpp;
2029
2030 lkp = xfs_btree_key_addr(cur, lrecs, left);
2031 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2032 rkp = xfs_btree_key_addr(cur, 1, right);
2033 rpp = xfs_btree_ptr_addr(cur, 1, right);
2034
2035#ifdef DEBUG
2036 for (i = rrecs - 1; i >= 0; i--) {
2037 error = xfs_btree_check_ptr(cur, rpp, i, level);
2038 if (error)
2039 goto error0;
2040 }
2041#endif
2042
2043 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2044 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2045
2046#ifdef DEBUG
2047 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2048 if (error)
2049 goto error0;
2050#endif
2051
2052 /* Now put the new data in, and log it. */
2053 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2054 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2055
2056 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2057 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2058
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002059 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2060 xfs_btree_key_addr(cur, 2, right)));
Christoph Hellwig9eaead52008-10-30 16:56:43 +11002061 } else {
2062 /* It's a leaf. make a hole in the records */
2063 union xfs_btree_rec *lrp;
2064 union xfs_btree_rec *rrp;
2065
2066 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2067 rrp = xfs_btree_rec_addr(cur, 1, right);
2068
2069 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2070
2071 /* Now put the new data in, and log it. */
2072 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2073 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2074
2075 cur->bc_ops->init_key_from_rec(&key, rrp);
2076 rkp = &key;
2077
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002078 ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2079 xfs_btree_rec_addr(cur, 2, right)));
Christoph Hellwig9eaead52008-10-30 16:56:43 +11002080 }
2081
2082 /*
2083 * Decrement and log left's numrecs, bump and log right's numrecs.
2084 */
2085 xfs_btree_set_numrecs(left, --lrecs);
2086 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2087
2088 xfs_btree_set_numrecs(right, ++rrecs);
2089 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2090
2091 /*
2092 * Using a temporary cursor, update the parent key values of the
2093 * block on the right.
2094 */
2095 error = xfs_btree_dup_cursor(cur, &tcur);
2096 if (error)
2097 goto error0;
2098 i = xfs_btree_lastrec(tcur, level);
2099 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2100
2101 error = xfs_btree_increment(tcur, level, &i);
2102 if (error)
2103 goto error1;
2104
2105 error = xfs_btree_updkey(tcur, rkp, level + 1);
2106 if (error)
2107 goto error1;
2108
2109 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2110
2111 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2112 *stat = 1;
2113 return 0;
2114
2115out0:
2116 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2117 *stat = 0;
2118 return 0;
2119
2120error0:
2121 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2122 return error;
2123
2124error1:
2125 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2126 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2127 return error;
2128}
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +11002129
2130/*
2131 * Split cur/level block in half.
2132 * Return new block number and the key to its first
2133 * record (to be inserted into parent).
2134 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11002135STATIC int /* error */
Christoph Hellwigf5eb8e72008-10-30 16:57:03 +11002136xfs_btree_split(
2137 struct xfs_btree_cur *cur,
2138 int level,
2139 union xfs_btree_ptr *ptrp,
2140 union xfs_btree_key *key,
2141 struct xfs_btree_cur **curp,
2142 int *stat) /* success/failure */
2143{
2144 union xfs_btree_ptr lptr; /* left sibling block ptr */
2145 struct xfs_buf *lbp; /* left buffer pointer */
2146 struct xfs_btree_block *left; /* left btree block */
2147 union xfs_btree_ptr rptr; /* right sibling block ptr */
2148 struct xfs_buf *rbp; /* right buffer pointer */
2149 struct xfs_btree_block *right; /* right btree block */
2150 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2151 struct xfs_buf *rrbp; /* right-right buffer pointer */
2152 struct xfs_btree_block *rrblock; /* right-right btree block */
2153 int lrecs;
2154 int rrecs;
2155 int src_index;
2156 int error; /* error return value */
2157#ifdef DEBUG
2158 int i;
2159#endif
2160
2161 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2162 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2163
2164 XFS_BTREE_STATS_INC(cur, split);
2165
2166 /* Set up left block (current one). */
2167 left = xfs_btree_get_block(cur, level, &lbp);
2168
2169#ifdef DEBUG
2170 error = xfs_btree_check_block(cur, left, level, lbp);
2171 if (error)
2172 goto error0;
2173#endif
2174
2175 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2176
2177 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2178 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2179 if (error)
2180 goto error0;
2181 if (*stat == 0)
2182 goto out0;
2183 XFS_BTREE_STATS_INC(cur, alloc);
2184
2185 /* Set up the new block as "right". */
2186 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2187 if (error)
2188 goto error0;
2189
2190 /* Fill in the btree header for the new right block. */
2191 xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
2192
2193 /*
2194 * Split the entries between the old and the new block evenly.
2195 * Make sure that if there's an odd number of entries now, that
2196 * each new block will have the same number of entries.
2197 */
2198 lrecs = xfs_btree_get_numrecs(left);
2199 rrecs = lrecs / 2;
2200 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2201 rrecs++;
2202 src_index = (lrecs - rrecs + 1);
2203
2204 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2205
2206 /*
2207 * Copy btree block entries from the left block over to the
2208 * new block, the right. Update the right block and log the
2209 * changes.
2210 */
2211 if (level > 0) {
2212 /* It's a non-leaf. Move keys and pointers. */
2213 union xfs_btree_key *lkp; /* left btree key */
2214 union xfs_btree_ptr *lpp; /* left address pointer */
2215 union xfs_btree_key *rkp; /* right btree key */
2216 union xfs_btree_ptr *rpp; /* right address pointer */
2217
2218 lkp = xfs_btree_key_addr(cur, src_index, left);
2219 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2220 rkp = xfs_btree_key_addr(cur, 1, right);
2221 rpp = xfs_btree_ptr_addr(cur, 1, right);
2222
2223#ifdef DEBUG
2224 for (i = src_index; i < rrecs; i++) {
2225 error = xfs_btree_check_ptr(cur, lpp, i, level);
2226 if (error)
2227 goto error0;
2228 }
2229#endif
2230
2231 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2232 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2233
2234 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2235 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2236
2237 /* Grab the keys to the entries moved to the right block */
2238 xfs_btree_copy_keys(cur, key, rkp, 1);
2239 } else {
2240 /* It's a leaf. Move records. */
2241 union xfs_btree_rec *lrp; /* left record pointer */
2242 union xfs_btree_rec *rrp; /* right record pointer */
2243
2244 lrp = xfs_btree_rec_addr(cur, src_index, left);
2245 rrp = xfs_btree_rec_addr(cur, 1, right);
2246
2247 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2248 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2249
2250 cur->bc_ops->init_key_from_rec(key,
2251 xfs_btree_rec_addr(cur, 1, right));
2252 }
2253
2254
2255 /*
2256 * Find the left block number by looking in the buffer.
2257 * Adjust numrecs, sibling pointers.
2258 */
2259 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2260 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2261 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2262 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2263
2264 lrecs -= rrecs;
2265 xfs_btree_set_numrecs(left, lrecs);
2266 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2267
2268 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2269 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2270
2271 /*
2272 * If there's a block to the new block's right, make that block
2273 * point back to right instead of to left.
2274 */
2275 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2276 error = xfs_btree_read_buf_block(cur, &rrptr, level,
2277 0, &rrblock, &rrbp);
2278 if (error)
2279 goto error0;
2280 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2281 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2282 }
2283 /*
2284 * If the cursor is really in the right block, move it there.
2285 * If it's just pointing past the last entry in left, then we'll
2286 * insert there, so don't change anything in that case.
2287 */
2288 if (cur->bc_ptrs[level] > lrecs + 1) {
2289 xfs_btree_setbuf(cur, level, rbp);
2290 cur->bc_ptrs[level] -= lrecs;
2291 }
2292 /*
2293 * If there are more levels, we'll need another cursor which refers
2294 * the right block, no matter where this cursor was.
2295 */
2296 if (level + 1 < cur->bc_nlevels) {
2297 error = xfs_btree_dup_cursor(cur, curp);
2298 if (error)
2299 goto error0;
2300 (*curp)->bc_ptrs[level + 1]++;
2301 }
2302 *ptrp = rptr;
2303 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2304 *stat = 1;
2305 return 0;
2306out0:
2307 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2308 *stat = 0;
2309 return 0;
2310
2311error0:
2312 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2313 return error;
2314}
Christoph Hellwig344207c2008-10-30 16:57:16 +11002315
2316/*
Christoph Hellwigea77b0a2008-10-30 16:57:28 +11002317 * Copy the old inode root contents into a real block and make the
2318 * broot point to it.
2319 */
2320int /* error */
2321xfs_btree_new_iroot(
2322 struct xfs_btree_cur *cur, /* btree cursor */
2323 int *logflags, /* logging flags for inode */
2324 int *stat) /* return status - 0 fail */
2325{
2326 struct xfs_buf *cbp; /* buffer for cblock */
2327 struct xfs_btree_block *block; /* btree block */
2328 struct xfs_btree_block *cblock; /* child btree block */
2329 union xfs_btree_key *ckp; /* child key pointer */
2330 union xfs_btree_ptr *cpp; /* child ptr pointer */
2331 union xfs_btree_key *kp; /* pointer to btree key */
2332 union xfs_btree_ptr *pp; /* pointer to block addr */
2333 union xfs_btree_ptr nptr; /* new block addr */
2334 int level; /* btree level */
2335 int error; /* error return code */
2336#ifdef DEBUG
2337 int i; /* loop counter */
2338#endif
2339
2340 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2341 XFS_BTREE_STATS_INC(cur, newroot);
2342
2343 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2344
2345 level = cur->bc_nlevels - 1;
2346
2347 block = xfs_btree_get_iroot(cur);
2348 pp = xfs_btree_ptr_addr(cur, 1, block);
2349
2350 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2351 error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2352 if (error)
2353 goto error0;
2354 if (*stat == 0) {
2355 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2356 return 0;
2357 }
2358 XFS_BTREE_STATS_INC(cur, alloc);
2359
2360 /* Copy the root into a real block. */
2361 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2362 if (error)
2363 goto error0;
2364
2365 memcpy(cblock, block, xfs_btree_block_len(cur));
2366
2367 be16_add_cpu(&block->bb_level, 1);
2368 xfs_btree_set_numrecs(block, 1);
2369 cur->bc_nlevels++;
2370 cur->bc_ptrs[level + 1] = 1;
2371
2372 kp = xfs_btree_key_addr(cur, 1, block);
2373 ckp = xfs_btree_key_addr(cur, 1, cblock);
2374 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2375
2376 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2377#ifdef DEBUG
2378 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2379 error = xfs_btree_check_ptr(cur, pp, i, level);
2380 if (error)
2381 goto error0;
2382 }
2383#endif
2384 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2385
2386#ifdef DEBUG
2387 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2388 if (error)
2389 goto error0;
2390#endif
2391 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2392
2393 xfs_iroot_realloc(cur->bc_private.b.ip,
2394 1 - xfs_btree_get_numrecs(cblock),
2395 cur->bc_private.b.whichfork);
2396
2397 xfs_btree_setbuf(cur, level, cbp);
2398
2399 /*
2400 * Do all this logging at the end so that
2401 * the root is at the right level.
2402 */
2403 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2404 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2405 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2406
2407 *logflags |=
Eric Sandeen9d87c312009-01-14 23:22:07 -06002408 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
Christoph Hellwigea77b0a2008-10-30 16:57:28 +11002409 *stat = 1;
2410 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2411 return 0;
2412error0:
2413 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2414 return error;
2415}
2416
2417/*
Christoph Hellwig344207c2008-10-30 16:57:16 +11002418 * Allocate a new root block, fill it in.
2419 */
Christoph Hellwig3cc75242008-10-30 16:58:41 +11002420STATIC int /* error */
Christoph Hellwig344207c2008-10-30 16:57:16 +11002421xfs_btree_new_root(
2422 struct xfs_btree_cur *cur, /* btree cursor */
2423 int *stat) /* success/failure */
2424{
2425 struct xfs_btree_block *block; /* one half of the old root block */
2426 struct xfs_buf *bp; /* buffer containing block */
2427 int error; /* error return value */
2428 struct xfs_buf *lbp; /* left buffer pointer */
2429 struct xfs_btree_block *left; /* left btree block */
2430 struct xfs_buf *nbp; /* new (root) buffer */
2431 struct xfs_btree_block *new; /* new (root) btree block */
2432 int nptr; /* new value for key index, 1 or 2 */
2433 struct xfs_buf *rbp; /* right buffer pointer */
2434 struct xfs_btree_block *right; /* right btree block */
2435 union xfs_btree_ptr rptr;
2436 union xfs_btree_ptr lptr;
2437
2438 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2439 XFS_BTREE_STATS_INC(cur, newroot);
2440
2441 /* initialise our start point from the cursor */
2442 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2443
2444 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2445 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2446 if (error)
2447 goto error0;
2448 if (*stat == 0)
2449 goto out0;
2450 XFS_BTREE_STATS_INC(cur, alloc);
2451
2452 /* Set up the new block. */
2453 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2454 if (error)
2455 goto error0;
2456
2457 /* Set the root in the holding structure increasing the level by 1. */
2458 cur->bc_ops->set_root(cur, &lptr, 1);
2459
2460 /*
2461 * At the previous root level there are now two blocks: the old root,
2462 * and the new block generated when it was split. We don't know which
2463 * one the cursor is pointing at, so we set up variables "left" and
2464 * "right" for each case.
2465 */
2466 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2467
2468#ifdef DEBUG
2469 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2470 if (error)
2471 goto error0;
2472#endif
2473
2474 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2475 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2476 /* Our block is left, pick up the right block. */
2477 lbp = bp;
2478 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2479 left = block;
2480 error = xfs_btree_read_buf_block(cur, &rptr,
2481 cur->bc_nlevels - 1, 0, &right, &rbp);
2482 if (error)
2483 goto error0;
2484 bp = rbp;
2485 nptr = 1;
2486 } else {
2487 /* Our block is right, pick up the left block. */
2488 rbp = bp;
2489 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2490 right = block;
2491 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2492 error = xfs_btree_read_buf_block(cur, &lptr,
2493 cur->bc_nlevels - 1, 0, &left, &lbp);
2494 if (error)
2495 goto error0;
2496 bp = lbp;
2497 nptr = 2;
2498 }
2499 /* Fill in the new block's btree header and log it. */
2500 xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
2501 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2502 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2503 !xfs_btree_ptr_is_null(cur, &rptr));
2504
2505 /* Fill in the key data in the new root. */
2506 if (xfs_btree_get_level(left) > 0) {
2507 xfs_btree_copy_keys(cur,
2508 xfs_btree_key_addr(cur, 1, new),
2509 xfs_btree_key_addr(cur, 1, left), 1);
2510 xfs_btree_copy_keys(cur,
2511 xfs_btree_key_addr(cur, 2, new),
2512 xfs_btree_key_addr(cur, 1, right), 1);
2513 } else {
2514 cur->bc_ops->init_key_from_rec(
2515 xfs_btree_key_addr(cur, 1, new),
2516 xfs_btree_rec_addr(cur, 1, left));
2517 cur->bc_ops->init_key_from_rec(
2518 xfs_btree_key_addr(cur, 2, new),
2519 xfs_btree_rec_addr(cur, 1, right));
2520 }
2521 xfs_btree_log_keys(cur, nbp, 1, 2);
2522
2523 /* Fill in the pointer data in the new root. */
2524 xfs_btree_copy_ptrs(cur,
2525 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2526 xfs_btree_copy_ptrs(cur,
2527 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2528 xfs_btree_log_ptrs(cur, nbp, 1, 2);
2529
2530 /* Fix up the cursor. */
2531 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2532 cur->bc_ptrs[cur->bc_nlevels] = nptr;
2533 cur->bc_nlevels++;
2534 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2535 *stat = 1;
2536 return 0;
2537error0:
2538 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2539 return error;
2540out0:
2541 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2542 *stat = 0;
2543 return 0;
2544}
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002545
2546STATIC int
2547xfs_btree_make_block_unfull(
2548 struct xfs_btree_cur *cur, /* btree cursor */
2549 int level, /* btree level */
2550 int numrecs,/* # of recs in block */
2551 int *oindex,/* old tree index */
2552 int *index, /* new tree index */
2553 union xfs_btree_ptr *nptr, /* new btree ptr */
2554 struct xfs_btree_cur **ncur, /* new btree cursor */
2555 union xfs_btree_rec *nrec, /* new record */
2556 int *stat)
2557{
2558 union xfs_btree_key key; /* new btree key value */
2559 int error = 0;
2560
2561 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2562 level == cur->bc_nlevels - 1) {
2563 struct xfs_inode *ip = cur->bc_private.b.ip;
2564
2565 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2566 /* A root block that can be made bigger. */
2567
2568 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2569 } else {
2570 /* A root block that needs replacing */
2571 int logflags = 0;
2572
2573 error = xfs_btree_new_iroot(cur, &logflags, stat);
2574 if (error || *stat == 0)
2575 return error;
2576
2577 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2578 }
2579
2580 return 0;
2581 }
2582
2583 /* First, try shifting an entry to the right neighbor. */
2584 error = xfs_btree_rshift(cur, level, stat);
2585 if (error || *stat)
2586 return error;
2587
2588 /* Next, try shifting an entry to the left neighbor. */
2589 error = xfs_btree_lshift(cur, level, stat);
2590 if (error)
2591 return error;
2592
2593 if (*stat) {
2594 *oindex = *index = cur->bc_ptrs[level];
2595 return 0;
2596 }
2597
2598 /*
2599 * Next, try splitting the current block in half.
2600 *
2601 * If this works we have to re-set our variables because we
2602 * could be in a different block now.
2603 */
2604 error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2605 if (error || *stat == 0)
2606 return error;
2607
2608
2609 *index = cur->bc_ptrs[level];
2610 cur->bc_ops->init_rec_from_key(&key, nrec);
2611 return 0;
2612}
2613
2614/*
2615 * Insert one record/level. Return information to the caller
2616 * allowing the next level up to proceed if necessary.
2617 */
2618STATIC int
2619xfs_btree_insrec(
2620 struct xfs_btree_cur *cur, /* btree cursor */
2621 int level, /* level to insert record at */
2622 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
2623 union xfs_btree_rec *recp, /* i/o: record data inserted */
2624 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
2625 int *stat) /* success/failure */
2626{
2627 struct xfs_btree_block *block; /* btree block */
2628 struct xfs_buf *bp; /* buffer for block */
2629 union xfs_btree_key key; /* btree key */
2630 union xfs_btree_ptr nptr; /* new block ptr */
2631 struct xfs_btree_cur *ncur; /* new btree cursor */
2632 union xfs_btree_rec nrec; /* new record count */
2633 int optr; /* old key/record index */
2634 int ptr; /* key/record index */
2635 int numrecs;/* number of records */
2636 int error; /* error return value */
2637#ifdef DEBUG
2638 int i;
2639#endif
2640
2641 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2642 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2643
2644 ncur = NULL;
2645
2646 /*
2647 * If we have an external root pointer, and we've made it to the
2648 * root level, allocate a new root block and we're done.
2649 */
2650 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2651 (level >= cur->bc_nlevels)) {
2652 error = xfs_btree_new_root(cur, stat);
2653 xfs_btree_set_ptr_null(cur, ptrp);
2654
2655 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2656 return error;
2657 }
2658
2659 /* If we're off the left edge, return failure. */
2660 ptr = cur->bc_ptrs[level];
2661 if (ptr == 0) {
2662 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2663 *stat = 0;
2664 return 0;
2665 }
2666
2667 /* Make a key out of the record data to be inserted, and save it. */
2668 cur->bc_ops->init_key_from_rec(&key, recp);
2669
2670 optr = ptr;
2671
2672 XFS_BTREE_STATS_INC(cur, insrec);
2673
2674 /* Get pointers to the btree buffer and block. */
2675 block = xfs_btree_get_block(cur, level, &bp);
2676 numrecs = xfs_btree_get_numrecs(block);
2677
2678#ifdef DEBUG
2679 error = xfs_btree_check_block(cur, block, level, bp);
2680 if (error)
2681 goto error0;
2682
2683 /* Check that the new entry is being inserted in the right place. */
2684 if (ptr <= numrecs) {
2685 if (level == 0) {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002686 ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2687 xfs_btree_rec_addr(cur, ptr, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002688 } else {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002689 ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2690 xfs_btree_key_addr(cur, ptr, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002691 }
2692 }
2693#endif
2694
2695 /*
2696 * If the block is full, we can't insert the new entry until we
2697 * make the block un-full.
2698 */
2699 xfs_btree_set_ptr_null(cur, &nptr);
2700 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2701 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2702 &optr, &ptr, &nptr, &ncur, &nrec, stat);
2703 if (error || *stat == 0)
2704 goto error0;
2705 }
2706
2707 /*
2708 * The current block may have changed if the block was
2709 * previously full and we have just made space in it.
2710 */
2711 block = xfs_btree_get_block(cur, level, &bp);
2712 numrecs = xfs_btree_get_numrecs(block);
2713
2714#ifdef DEBUG
2715 error = xfs_btree_check_block(cur, block, level, bp);
2716 if (error)
2717 return error;
2718#endif
2719
2720 /*
2721 * At this point we know there's room for our new entry in the block
2722 * we're pointing at.
2723 */
2724 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2725
2726 if (level > 0) {
2727 /* It's a nonleaf. make a hole in the keys and ptrs */
2728 union xfs_btree_key *kp;
2729 union xfs_btree_ptr *pp;
2730
2731 kp = xfs_btree_key_addr(cur, ptr, block);
2732 pp = xfs_btree_ptr_addr(cur, ptr, block);
2733
2734#ifdef DEBUG
2735 for (i = numrecs - ptr; i >= 0; i--) {
2736 error = xfs_btree_check_ptr(cur, pp, i, level);
2737 if (error)
2738 return error;
2739 }
2740#endif
2741
2742 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2743 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2744
2745#ifdef DEBUG
2746 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2747 if (error)
2748 goto error0;
2749#endif
2750
2751 /* Now put the new data in, bump numrecs and log it. */
2752 xfs_btree_copy_keys(cur, kp, &key, 1);
2753 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2754 numrecs++;
2755 xfs_btree_set_numrecs(block, numrecs);
2756 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2757 xfs_btree_log_keys(cur, bp, ptr, numrecs);
2758#ifdef DEBUG
2759 if (ptr < numrecs) {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002760 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2761 xfs_btree_key_addr(cur, ptr + 1, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002762 }
2763#endif
2764 } else {
2765 /* It's a leaf. make a hole in the records */
2766 union xfs_btree_rec *rp;
2767
2768 rp = xfs_btree_rec_addr(cur, ptr, block);
2769
2770 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2771
2772 /* Now put the new data in, bump numrecs and log it. */
2773 xfs_btree_copy_recs(cur, rp, recp, 1);
2774 xfs_btree_set_numrecs(block, ++numrecs);
2775 xfs_btree_log_recs(cur, bp, ptr, numrecs);
2776#ifdef DEBUG
2777 if (ptr < numrecs) {
Christoph Hellwig4a26e662008-10-30 16:58:32 +11002778 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2779 xfs_btree_rec_addr(cur, ptr + 1, block)));
Christoph Hellwig4b22a572008-10-30 16:57:40 +11002780 }
2781#endif
2782 }
2783
2784 /* Log the new number of records in the btree header. */
2785 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2786
2787 /* If we inserted at the start of a block, update the parents' keys. */
2788 if (optr == 1) {
2789 error = xfs_btree_updkey(cur, &key, level + 1);
2790 if (error)
2791 goto error0;
2792 }
2793
2794 /*
2795 * If we are tracking the last record in the tree and
2796 * we are at the far right edge of the tree, update it.
2797 */
2798 if (xfs_btree_is_lastrec(cur, block, level)) {
2799 cur->bc_ops->update_lastrec(cur, block, recp,
2800 ptr, LASTREC_INSREC);
2801 }
2802
2803 /*
2804 * Return the new block number, if any.
2805 * If there is one, give back a record value and a cursor too.
2806 */
2807 *ptrp = nptr;
2808 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2809 *recp = nrec;
2810 *curp = ncur;
2811 }
2812
2813 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2814 *stat = 1;
2815 return 0;
2816
2817error0:
2818 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2819 return error;
2820}
2821
2822/*
2823 * Insert the record at the point referenced by cur.
2824 *
2825 * A multi-level split of the tree on insert will invalidate the original
2826 * cursor. All callers of this function should assume that the cursor is
2827 * no longer valid and revalidate it.
2828 */
2829int
2830xfs_btree_insert(
2831 struct xfs_btree_cur *cur,
2832 int *stat)
2833{
2834 int error; /* error return value */
2835 int i; /* result value, 0 for failure */
2836 int level; /* current level number in btree */
2837 union xfs_btree_ptr nptr; /* new block number (split result) */
2838 struct xfs_btree_cur *ncur; /* new cursor (split result) */
2839 struct xfs_btree_cur *pcur; /* previous level's cursor */
2840 union xfs_btree_rec rec; /* record to insert */
2841
2842 level = 0;
2843 ncur = NULL;
2844 pcur = cur;
2845
2846 xfs_btree_set_ptr_null(cur, &nptr);
2847 cur->bc_ops->init_rec_from_cur(cur, &rec);
2848
2849 /*
2850 * Loop going up the tree, starting at the leaf level.
2851 * Stop when we don't get a split block, that must mean that
2852 * the insert is finished with this level.
2853 */
2854 do {
2855 /*
2856 * Insert nrec/nptr into this level of the tree.
2857 * Note if we fail, nptr will be null.
2858 */
2859 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
2860 if (error) {
2861 if (pcur != cur)
2862 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
2863 goto error0;
2864 }
2865
2866 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2867 level++;
2868
2869 /*
2870 * See if the cursor we just used is trash.
2871 * Can't trash the caller's cursor, but otherwise we should
2872 * if ncur is a new cursor or we're about to be done.
2873 */
2874 if (pcur != cur &&
2875 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
2876 /* Save the state from the cursor before we trash it */
2877 if (cur->bc_ops->update_cursor)
2878 cur->bc_ops->update_cursor(pcur, cur);
2879 cur->bc_nlevels = pcur->bc_nlevels;
2880 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
2881 }
2882 /* If we got a new cursor, switch to it. */
2883 if (ncur) {
2884 pcur = ncur;
2885 ncur = NULL;
2886 }
2887 } while (!xfs_btree_ptr_is_null(cur, &nptr));
2888
2889 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2890 *stat = i;
2891 return 0;
2892error0:
2893 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2894 return error;
2895}
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11002896
2897/*
2898 * Try to merge a non-leaf block back into the inode root.
2899 *
2900 * Note: the killroot names comes from the fact that we're effectively
2901 * killing the old root block. But because we can't just delete the
2902 * inode we have to copy the single block it was pointing to into the
2903 * inode.
2904 */
Eric Sandeend96f8f82009-07-02 00:09:33 -05002905STATIC int
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11002906xfs_btree_kill_iroot(
2907 struct xfs_btree_cur *cur)
2908{
2909 int whichfork = cur->bc_private.b.whichfork;
2910 struct xfs_inode *ip = cur->bc_private.b.ip;
2911 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
2912 struct xfs_btree_block *block;
2913 struct xfs_btree_block *cblock;
2914 union xfs_btree_key *kp;
2915 union xfs_btree_key *ckp;
2916 union xfs_btree_ptr *pp;
2917 union xfs_btree_ptr *cpp;
2918 struct xfs_buf *cbp;
2919 int level;
2920 int index;
2921 int numrecs;
2922#ifdef DEBUG
2923 union xfs_btree_ptr ptr;
2924 int i;
2925#endif
2926
2927 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2928
2929 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2930 ASSERT(cur->bc_nlevels > 1);
2931
2932 /*
2933 * Don't deal with the root block needs to be a leaf case.
2934 * We're just going to turn the thing back into extents anyway.
2935 */
2936 level = cur->bc_nlevels - 1;
2937 if (level == 1)
2938 goto out0;
2939
2940 /*
2941 * Give up if the root has multiple children.
2942 */
2943 block = xfs_btree_get_iroot(cur);
2944 if (xfs_btree_get_numrecs(block) != 1)
2945 goto out0;
2946
2947 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
2948 numrecs = xfs_btree_get_numrecs(cblock);
2949
2950 /*
2951 * Only do this if the next level will fit.
2952 * Then the data must be copied up to the inode,
2953 * instead of freeing the root you free the next level.
2954 */
2955 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
2956 goto out0;
2957
2958 XFS_BTREE_STATS_INC(cur, killroot);
2959
2960#ifdef DEBUG
2961 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
2962 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2963 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2964 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2965#endif
2966
2967 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
2968 if (index) {
2969 xfs_iroot_realloc(cur->bc_private.b.ip, index,
2970 cur->bc_private.b.whichfork);
Christoph Hellwig7cc95a82008-10-30 17:14:34 +11002971 block = ifp->if_broot;
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11002972 }
2973
2974 be16_add_cpu(&block->bb_numrecs, index);
2975 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
2976
2977 kp = xfs_btree_key_addr(cur, 1, block);
2978 ckp = xfs_btree_key_addr(cur, 1, cblock);
2979 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
2980
2981 pp = xfs_btree_ptr_addr(cur, 1, block);
2982 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2983#ifdef DEBUG
2984 for (i = 0; i < numrecs; i++) {
2985 int error;
2986
2987 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
2988 if (error) {
2989 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2990 return error;
2991 }
2992 }
2993#endif
2994 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
2995
2996 cur->bc_ops->free_block(cur, cbp);
2997 XFS_BTREE_STATS_INC(cur, free);
2998
2999 cur->bc_bufs[level - 1] = NULL;
3000 be16_add_cpu(&block->bb_level, -1);
3001 xfs_trans_log_inode(cur->bc_tp, ip,
Eric Sandeen9d87c312009-01-14 23:22:07 -06003002 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
Christoph Hellwigd4b3a4b2008-10-30 16:57:51 +11003003 cur->bc_nlevels--;
3004out0:
3005 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3006 return 0;
3007}
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003008
Christoph Hellwigc0e59e12010-09-07 23:34:07 +00003009/*
3010 * Kill the current root node, and replace it with it's only child node.
3011 */
3012STATIC int
3013xfs_btree_kill_root(
3014 struct xfs_btree_cur *cur,
3015 struct xfs_buf *bp,
3016 int level,
3017 union xfs_btree_ptr *newroot)
3018{
3019 int error;
3020
3021 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3022 XFS_BTREE_STATS_INC(cur, killroot);
3023
3024 /*
3025 * Update the root pointer, decreasing the level by 1 and then
3026 * free the old root.
3027 */
3028 cur->bc_ops->set_root(cur, newroot, -1);
3029
3030 error = cur->bc_ops->free_block(cur, bp);
3031 if (error) {
3032 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3033 return error;
3034 }
3035
3036 XFS_BTREE_STATS_INC(cur, free);
3037
3038 cur->bc_bufs[level] = NULL;
3039 cur->bc_ra[level] = 0;
3040 cur->bc_nlevels--;
3041
3042 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3043 return 0;
3044}
3045
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003046STATIC int
3047xfs_btree_dec_cursor(
3048 struct xfs_btree_cur *cur,
3049 int level,
3050 int *stat)
3051{
3052 int error;
3053 int i;
3054
3055 if (level > 0) {
3056 error = xfs_btree_decrement(cur, level, &i);
3057 if (error)
3058 return error;
3059 }
3060
3061 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3062 *stat = 1;
3063 return 0;
3064}
3065
3066/*
3067 * Single level of the btree record deletion routine.
3068 * Delete record pointed to by cur/level.
3069 * Remove the record from its block then rebalance the tree.
3070 * Return 0 for error, 1 for done, 2 to go on to the next level.
3071 */
3072STATIC int /* error */
3073xfs_btree_delrec(
3074 struct xfs_btree_cur *cur, /* btree cursor */
3075 int level, /* level removing record from */
3076 int *stat) /* fail/done/go-on */
3077{
3078 struct xfs_btree_block *block; /* btree block */
3079 union xfs_btree_ptr cptr; /* current block ptr */
3080 struct xfs_buf *bp; /* buffer for block */
3081 int error; /* error return value */
3082 int i; /* loop counter */
3083 union xfs_btree_key key; /* storage for keyp */
3084 union xfs_btree_key *keyp = &key; /* passed to the next level */
3085 union xfs_btree_ptr lptr; /* left sibling block ptr */
3086 struct xfs_buf *lbp; /* left buffer pointer */
3087 struct xfs_btree_block *left; /* left btree block */
3088 int lrecs = 0; /* left record count */
3089 int ptr; /* key/record index */
3090 union xfs_btree_ptr rptr; /* right sibling block ptr */
3091 struct xfs_buf *rbp; /* right buffer pointer */
3092 struct xfs_btree_block *right; /* right btree block */
3093 struct xfs_btree_block *rrblock; /* right-right btree block */
3094 struct xfs_buf *rrbp; /* right-right buffer pointer */
3095 int rrecs = 0; /* right record count */
3096 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3097 int numrecs; /* temporary numrec count */
3098
3099 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3100 XFS_BTREE_TRACE_ARGI(cur, level);
3101
3102 tcur = NULL;
3103
3104 /* Get the index of the entry being deleted, check for nothing there. */
3105 ptr = cur->bc_ptrs[level];
3106 if (ptr == 0) {
3107 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3108 *stat = 0;
3109 return 0;
3110 }
3111
3112 /* Get the buffer & block containing the record or key/ptr. */
3113 block = xfs_btree_get_block(cur, level, &bp);
3114 numrecs = xfs_btree_get_numrecs(block);
3115
3116#ifdef DEBUG
3117 error = xfs_btree_check_block(cur, block, level, bp);
3118 if (error)
3119 goto error0;
3120#endif
3121
3122 /* Fail if we're off the end of the block. */
3123 if (ptr > numrecs) {
3124 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3125 *stat = 0;
3126 return 0;
3127 }
3128
3129 XFS_BTREE_STATS_INC(cur, delrec);
3130 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3131
3132 /* Excise the entries being deleted. */
3133 if (level > 0) {
3134 /* It's a nonleaf. operate on keys and ptrs */
3135 union xfs_btree_key *lkp;
3136 union xfs_btree_ptr *lpp;
3137
3138 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3139 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3140
3141#ifdef DEBUG
3142 for (i = 0; i < numrecs - ptr; i++) {
3143 error = xfs_btree_check_ptr(cur, lpp, i, level);
3144 if (error)
3145 goto error0;
3146 }
3147#endif
3148
3149 if (ptr < numrecs) {
3150 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3151 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3152 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3153 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3154 }
3155
3156 /*
3157 * If it's the first record in the block, we'll need to pass a
3158 * key up to the next level (updkey).
3159 */
3160 if (ptr == 1)
3161 keyp = xfs_btree_key_addr(cur, 1, block);
3162 } else {
3163 /* It's a leaf. operate on records */
3164 if (ptr < numrecs) {
3165 xfs_btree_shift_recs(cur,
3166 xfs_btree_rec_addr(cur, ptr + 1, block),
3167 -1, numrecs - ptr);
3168 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3169 }
3170
3171 /*
3172 * If it's the first record in the block, we'll need a key
3173 * structure to pass up to the next level (updkey).
3174 */
3175 if (ptr == 1) {
3176 cur->bc_ops->init_key_from_rec(&key,
3177 xfs_btree_rec_addr(cur, 1, block));
3178 keyp = &key;
3179 }
3180 }
3181
3182 /*
3183 * Decrement and log the number of entries in the block.
3184 */
3185 xfs_btree_set_numrecs(block, --numrecs);
3186 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3187
3188 /*
3189 * If we are tracking the last record in the tree and
3190 * we are at the far right edge of the tree, update it.
3191 */
3192 if (xfs_btree_is_lastrec(cur, block, level)) {
3193 cur->bc_ops->update_lastrec(cur, block, NULL,
3194 ptr, LASTREC_DELREC);
3195 }
3196
3197 /*
3198 * We're at the root level. First, shrink the root block in-memory.
3199 * Try to get rid of the next level down. If we can't then there's
3200 * nothing left to do.
3201 */
3202 if (level == cur->bc_nlevels - 1) {
3203 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3204 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3205 cur->bc_private.b.whichfork);
3206
3207 error = xfs_btree_kill_iroot(cur);
3208 if (error)
3209 goto error0;
3210
3211 error = xfs_btree_dec_cursor(cur, level, stat);
3212 if (error)
3213 goto error0;
3214 *stat = 1;
3215 return 0;
3216 }
3217
3218 /*
3219 * If this is the root level, and there's only one entry left,
3220 * and it's NOT the leaf level, then we can get rid of this
3221 * level.
3222 */
3223 if (numrecs == 1 && level > 0) {
3224 union xfs_btree_ptr *pp;
3225 /*
3226 * pp is still set to the first pointer in the block.
3227 * Make it the new root of the btree.
3228 */
3229 pp = xfs_btree_ptr_addr(cur, 1, block);
Christoph Hellwigc0e59e12010-09-07 23:34:07 +00003230 error = xfs_btree_kill_root(cur, bp, level, pp);
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003231 if (error)
3232 goto error0;
3233 } else if (level > 0) {
3234 error = xfs_btree_dec_cursor(cur, level, stat);
3235 if (error)
3236 goto error0;
3237 }
3238 *stat = 1;
3239 return 0;
3240 }
3241
3242 /*
3243 * If we deleted the leftmost entry in the block, update the
3244 * key values above us in the tree.
3245 */
3246 if (ptr == 1) {
3247 error = xfs_btree_updkey(cur, keyp, level + 1);
3248 if (error)
3249 goto error0;
3250 }
3251
3252 /*
3253 * If the number of records remaining in the block is at least
3254 * the minimum, we're done.
3255 */
3256 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3257 error = xfs_btree_dec_cursor(cur, level, stat);
3258 if (error)
3259 goto error0;
3260 return 0;
3261 }
3262
3263 /*
3264 * Otherwise, we have to move some records around to keep the
3265 * tree balanced. Look at the left and right sibling blocks to
3266 * see if we can re-balance by moving only one record.
3267 */
3268 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3269 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3270
3271 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3272 /*
3273 * One child of root, need to get a chance to copy its contents
3274 * into the root and delete it. Can't go up to next level,
3275 * there's nothing to delete there.
3276 */
3277 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3278 xfs_btree_ptr_is_null(cur, &lptr) &&
3279 level == cur->bc_nlevels - 2) {
3280 error = xfs_btree_kill_iroot(cur);
3281 if (!error)
3282 error = xfs_btree_dec_cursor(cur, level, stat);
3283 if (error)
3284 goto error0;
3285 return 0;
3286 }
3287 }
3288
3289 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3290 !xfs_btree_ptr_is_null(cur, &lptr));
3291
3292 /*
3293 * Duplicate the cursor so our btree manipulations here won't
3294 * disrupt the next level up.
3295 */
3296 error = xfs_btree_dup_cursor(cur, &tcur);
3297 if (error)
3298 goto error0;
3299
3300 /*
3301 * If there's a right sibling, see if it's ok to shift an entry
3302 * out of it.
3303 */
3304 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3305 /*
3306 * Move the temp cursor to the last entry in the next block.
3307 * Actually any entry but the first would suffice.
3308 */
3309 i = xfs_btree_lastrec(tcur, level);
3310 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3311
3312 error = xfs_btree_increment(tcur, level, &i);
3313 if (error)
3314 goto error0;
3315 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3316
3317 i = xfs_btree_lastrec(tcur, level);
3318 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3319
3320 /* Grab a pointer to the block. */
3321 right = xfs_btree_get_block(tcur, level, &rbp);
3322#ifdef DEBUG
3323 error = xfs_btree_check_block(tcur, right, level, rbp);
3324 if (error)
3325 goto error0;
3326#endif
3327 /* Grab the current block number, for future use. */
3328 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3329
3330 /*
3331 * If right block is full enough so that removing one entry
3332 * won't make it too empty, and left-shifting an entry out
3333 * of right to us works, we're done.
3334 */
3335 if (xfs_btree_get_numrecs(right) - 1 >=
3336 cur->bc_ops->get_minrecs(tcur, level)) {
3337 error = xfs_btree_lshift(tcur, level, &i);
3338 if (error)
3339 goto error0;
3340 if (i) {
3341 ASSERT(xfs_btree_get_numrecs(block) >=
3342 cur->bc_ops->get_minrecs(tcur, level));
3343
3344 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3345 tcur = NULL;
3346
3347 error = xfs_btree_dec_cursor(cur, level, stat);
3348 if (error)
3349 goto error0;
3350 return 0;
3351 }
3352 }
3353
3354 /*
3355 * Otherwise, grab the number of records in right for
3356 * future reference, and fix up the temp cursor to point
3357 * to our block again (last record).
3358 */
3359 rrecs = xfs_btree_get_numrecs(right);
3360 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3361 i = xfs_btree_firstrec(tcur, level);
3362 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3363
3364 error = xfs_btree_decrement(tcur, level, &i);
3365 if (error)
3366 goto error0;
3367 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3368 }
3369 }
3370
3371 /*
3372 * If there's a left sibling, see if it's ok to shift an entry
3373 * out of it.
3374 */
3375 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3376 /*
3377 * Move the temp cursor to the first entry in the
3378 * previous block.
3379 */
3380 i = xfs_btree_firstrec(tcur, level);
3381 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3382
3383 error = xfs_btree_decrement(tcur, level, &i);
3384 if (error)
3385 goto error0;
3386 i = xfs_btree_firstrec(tcur, level);
3387 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3388
3389 /* Grab a pointer to the block. */
3390 left = xfs_btree_get_block(tcur, level, &lbp);
3391#ifdef DEBUG
3392 error = xfs_btree_check_block(cur, left, level, lbp);
3393 if (error)
3394 goto error0;
3395#endif
3396 /* Grab the current block number, for future use. */
3397 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3398
3399 /*
3400 * If left block is full enough so that removing one entry
3401 * won't make it too empty, and right-shifting an entry out
3402 * of left to us works, we're done.
3403 */
3404 if (xfs_btree_get_numrecs(left) - 1 >=
3405 cur->bc_ops->get_minrecs(tcur, level)) {
3406 error = xfs_btree_rshift(tcur, level, &i);
3407 if (error)
3408 goto error0;
3409 if (i) {
3410 ASSERT(xfs_btree_get_numrecs(block) >=
3411 cur->bc_ops->get_minrecs(tcur, level));
3412 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3413 tcur = NULL;
3414 if (level == 0)
3415 cur->bc_ptrs[0]++;
3416 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3417 *stat = 1;
3418 return 0;
3419 }
3420 }
3421
3422 /*
3423 * Otherwise, grab the number of records in right for
3424 * future reference.
3425 */
3426 lrecs = xfs_btree_get_numrecs(left);
3427 }
3428
3429 /* Delete the temp cursor, we're done with it. */
3430 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3431 tcur = NULL;
3432
3433 /* If here, we need to do a join to keep the tree balanced. */
3434 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3435
3436 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3437 lrecs + xfs_btree_get_numrecs(block) <=
3438 cur->bc_ops->get_maxrecs(cur, level)) {
3439 /*
3440 * Set "right" to be the starting block,
3441 * "left" to be the left neighbor.
3442 */
3443 rptr = cptr;
3444 right = block;
3445 rbp = bp;
3446 error = xfs_btree_read_buf_block(cur, &lptr, level,
3447 0, &left, &lbp);
3448 if (error)
3449 goto error0;
3450
3451 /*
3452 * If that won't work, see if we can join with the right neighbor block.
3453 */
3454 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3455 rrecs + xfs_btree_get_numrecs(block) <=
3456 cur->bc_ops->get_maxrecs(cur, level)) {
3457 /*
3458 * Set "left" to be the starting block,
3459 * "right" to be the right neighbor.
3460 */
3461 lptr = cptr;
3462 left = block;
3463 lbp = bp;
3464 error = xfs_btree_read_buf_block(cur, &rptr, level,
3465 0, &right, &rbp);
3466 if (error)
3467 goto error0;
3468
3469 /*
3470 * Otherwise, we can't fix the imbalance.
3471 * Just return. This is probably a logic error, but it's not fatal.
3472 */
3473 } else {
3474 error = xfs_btree_dec_cursor(cur, level, stat);
3475 if (error)
3476 goto error0;
3477 return 0;
3478 }
3479
3480 rrecs = xfs_btree_get_numrecs(right);
3481 lrecs = xfs_btree_get_numrecs(left);
3482
3483 /*
3484 * We're now going to join "left" and "right" by moving all the stuff
3485 * in "right" to "left" and deleting "right".
3486 */
3487 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3488 if (level > 0) {
3489 /* It's a non-leaf. Move keys and pointers. */
3490 union xfs_btree_key *lkp; /* left btree key */
3491 union xfs_btree_ptr *lpp; /* left address pointer */
3492 union xfs_btree_key *rkp; /* right btree key */
3493 union xfs_btree_ptr *rpp; /* right address pointer */
3494
3495 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3496 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3497 rkp = xfs_btree_key_addr(cur, 1, right);
3498 rpp = xfs_btree_ptr_addr(cur, 1, right);
3499#ifdef DEBUG
3500 for (i = 1; i < rrecs; i++) {
3501 error = xfs_btree_check_ptr(cur, rpp, i, level);
3502 if (error)
3503 goto error0;
3504 }
3505#endif
3506 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3507 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3508
3509 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3510 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3511 } else {
3512 /* It's a leaf. Move records. */
3513 union xfs_btree_rec *lrp; /* left record pointer */
3514 union xfs_btree_rec *rrp; /* right record pointer */
3515
3516 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3517 rrp = xfs_btree_rec_addr(cur, 1, right);
3518
3519 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3520 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3521 }
3522
3523 XFS_BTREE_STATS_INC(cur, join);
3524
3525 /*
Malcolm Parsons9da096f2009-03-29 09:55:42 +02003526 * Fix up the number of records and right block pointer in the
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11003527 * surviving block, and log it.
3528 */
3529 xfs_btree_set_numrecs(left, lrecs + rrecs);
3530 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3531 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3532 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3533
3534 /* If there is a right sibling, point it to the remaining block. */
3535 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3536 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3537 error = xfs_btree_read_buf_block(cur, &cptr, level,
3538 0, &rrblock, &rrbp);
3539 if (error)
3540 goto error0;
3541 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3542 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3543 }
3544
3545 /* Free the deleted block. */
3546 error = cur->bc_ops->free_block(cur, rbp);
3547 if (error)
3548 goto error0;
3549 XFS_BTREE_STATS_INC(cur, free);
3550
3551 /*
3552 * If we joined with the left neighbor, set the buffer in the
3553 * cursor to the left block, and fix up the index.
3554 */
3555 if (bp != lbp) {
3556 cur->bc_bufs[level] = lbp;
3557 cur->bc_ptrs[level] += lrecs;
3558 cur->bc_ra[level] = 0;
3559 }
3560 /*
3561 * If we joined with the right neighbor and there's a level above
3562 * us, increment the cursor at that level.
3563 */
3564 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3565 (level + 1 < cur->bc_nlevels)) {
3566 error = xfs_btree_increment(cur, level + 1, &i);
3567 if (error)
3568 goto error0;
3569 }
3570
3571 /*
3572 * Readjust the ptr at this level if it's not a leaf, since it's
3573 * still pointing at the deletion point, which makes the cursor
3574 * inconsistent. If this makes the ptr 0, the caller fixes it up.
3575 * We can't use decrement because it would change the next level up.
3576 */
3577 if (level > 0)
3578 cur->bc_ptrs[level]--;
3579
3580 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3581 /* Return value means the next level up has something to do. */
3582 *stat = 2;
3583 return 0;
3584
3585error0:
3586 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3587 if (tcur)
3588 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3589 return error;
3590}
3591
3592/*
3593 * Delete the record pointed to by cur.
3594 * The cursor refers to the place where the record was (could be inserted)
3595 * when the operation returns.
3596 */
3597int /* error */
3598xfs_btree_delete(
3599 struct xfs_btree_cur *cur,
3600 int *stat) /* success/failure */
3601{
3602 int error; /* error return value */
3603 int level;
3604 int i;
3605
3606 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3607
3608 /*
3609 * Go up the tree, starting at leaf level.
3610 *
3611 * If 2 is returned then a join was done; go to the next level.
3612 * Otherwise we are done.
3613 */
3614 for (level = 0, i = 2; i == 2; level++) {
3615 error = xfs_btree_delrec(cur, level, &i);
3616 if (error)
3617 goto error0;
3618 }
3619
3620 if (i == 0) {
3621 for (level = 1; level < cur->bc_nlevels; level++) {
3622 if (cur->bc_ptrs[level] == 0) {
3623 error = xfs_btree_decrement(cur, level, &i);
3624 if (error)
3625 goto error0;
3626 break;
3627 }
3628 }
3629 }
3630
3631 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3632 *stat = i;
3633 return 0;
3634error0:
3635 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3636 return error;
3637}
Christoph Hellwig8cc938f2008-10-30 16:58:11 +11003638
3639/*
3640 * Get the data from the pointed-to record.
3641 */
3642int /* error */
3643xfs_btree_get_rec(
3644 struct xfs_btree_cur *cur, /* btree cursor */
3645 union xfs_btree_rec **recp, /* output: btree record */
3646 int *stat) /* output: success/failure */
3647{
3648 struct xfs_btree_block *block; /* btree block */
3649 struct xfs_buf *bp; /* buffer pointer */
3650 int ptr; /* record number */
3651#ifdef DEBUG
3652 int error; /* error return value */
3653#endif
3654
3655 ptr = cur->bc_ptrs[0];
3656 block = xfs_btree_get_block(cur, 0, &bp);
3657
3658#ifdef DEBUG
3659 error = xfs_btree_check_block(cur, block, 0, bp);
3660 if (error)
3661 return error;
3662#endif
3663
3664 /*
3665 * Off the right end or left end, return failure.
3666 */
3667 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3668 *stat = 0;
3669 return 0;
3670 }
3671
3672 /*
3673 * Point to the record and extract its data.
3674 */
3675 *recp = xfs_btree_rec_addr(cur, ptr, block);
3676 *stat = 1;
3677 return 0;
3678}