xref: /openbmc/linux/fs/xfs/libxfs/xfs_bmap_btree.c (revision b742d7b4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_bit.h"
13 #include "xfs_mount.h"
14 #include "xfs_inode.h"
15 #include "xfs_trans.h"
16 #include "xfs_alloc.h"
17 #include "xfs_btree.h"
18 #include "xfs_bmap_btree.h"
19 #include "xfs_bmap.h"
20 #include "xfs_error.h"
21 #include "xfs_quota.h"
22 #include "xfs_trace.h"
23 #include "xfs_rmap.h"
24 #include "xfs_ag.h"
25 
26 static struct kmem_cache	*xfs_bmbt_cur_cache;
27 
28 /*
29  * Convert on-disk form of btree root to in-memory form.
30  */
31 void
xfs_bmdr_to_bmbt(struct xfs_inode * ip,xfs_bmdr_block_t * dblock,int dblocklen,struct xfs_btree_block * rblock,int rblocklen)32 xfs_bmdr_to_bmbt(
33 	struct xfs_inode	*ip,
34 	xfs_bmdr_block_t	*dblock,
35 	int			dblocklen,
36 	struct xfs_btree_block	*rblock,
37 	int			rblocklen)
38 {
39 	struct xfs_mount	*mp = ip->i_mount;
40 	int			dmxr;
41 	xfs_bmbt_key_t		*fkp;
42 	__be64			*fpp;
43 	xfs_bmbt_key_t		*tkp;
44 	__be64			*tpp;
45 
46 	xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
47 				 XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
48 				 XFS_BTREE_LONG_PTRS);
49 	rblock->bb_level = dblock->bb_level;
50 	ASSERT(be16_to_cpu(rblock->bb_level) > 0);
51 	rblock->bb_numrecs = dblock->bb_numrecs;
52 	dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
53 	fkp = XFS_BMDR_KEY_ADDR(dblock, 1);
54 	tkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
55 	fpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
56 	tpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
57 	dmxr = be16_to_cpu(dblock->bb_numrecs);
58 	memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
59 	memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
60 }
61 
62 void
xfs_bmbt_disk_get_all(const struct xfs_bmbt_rec * rec,struct xfs_bmbt_irec * irec)63 xfs_bmbt_disk_get_all(
64 	const struct xfs_bmbt_rec *rec,
65 	struct xfs_bmbt_irec	*irec)
66 {
67 	uint64_t		l0 = get_unaligned_be64(&rec->l0);
68 	uint64_t		l1 = get_unaligned_be64(&rec->l1);
69 
70 	irec->br_startoff = (l0 & xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
71 	irec->br_startblock = ((l0 & xfs_mask64lo(9)) << 43) | (l1 >> 21);
72 	irec->br_blockcount = l1 & xfs_mask64lo(21);
73 	if (l0 >> (64 - BMBT_EXNTFLAG_BITLEN))
74 		irec->br_state = XFS_EXT_UNWRITTEN;
75 	else
76 		irec->br_state = XFS_EXT_NORM;
77 }
78 
79 /*
80  * Extract the blockcount field from an on disk bmap extent record.
81  */
82 xfs_filblks_t
xfs_bmbt_disk_get_blockcount(const struct xfs_bmbt_rec * r)83 xfs_bmbt_disk_get_blockcount(
84 	const struct xfs_bmbt_rec	*r)
85 {
86 	return (xfs_filblks_t)(be64_to_cpu(r->l1) & xfs_mask64lo(21));
87 }
88 
89 /*
90  * Extract the startoff field from a disk format bmap extent record.
91  */
92 xfs_fileoff_t
xfs_bmbt_disk_get_startoff(const struct xfs_bmbt_rec * r)93 xfs_bmbt_disk_get_startoff(
94 	const struct xfs_bmbt_rec	*r)
95 {
96 	return ((xfs_fileoff_t)be64_to_cpu(r->l0) &
97 		 xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
98 }
99 
100 /*
101  * Set all the fields in a bmap extent record from the uncompressed form.
102  */
103 void
xfs_bmbt_disk_set_all(struct xfs_bmbt_rec * r,struct xfs_bmbt_irec * s)104 xfs_bmbt_disk_set_all(
105 	struct xfs_bmbt_rec	*r,
106 	struct xfs_bmbt_irec	*s)
107 {
108 	int			extent_flag = (s->br_state != XFS_EXT_NORM);
109 
110 	ASSERT(s->br_state == XFS_EXT_NORM || s->br_state == XFS_EXT_UNWRITTEN);
111 	ASSERT(!(s->br_startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)));
112 	ASSERT(!(s->br_blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)));
113 	ASSERT(!(s->br_startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)));
114 
115 	put_unaligned_be64(
116 		((xfs_bmbt_rec_base_t)extent_flag << 63) |
117 		 ((xfs_bmbt_rec_base_t)s->br_startoff << 9) |
118 		 ((xfs_bmbt_rec_base_t)s->br_startblock >> 43), &r->l0);
119 	put_unaligned_be64(
120 		((xfs_bmbt_rec_base_t)s->br_startblock << 21) |
121 		 ((xfs_bmbt_rec_base_t)s->br_blockcount &
122 		  (xfs_bmbt_rec_base_t)xfs_mask64lo(21)), &r->l1);
123 }
124 
125 /*
126  * Convert in-memory form of btree root to on-disk form.
127  */
128 void
xfs_bmbt_to_bmdr(struct xfs_mount * mp,struct xfs_btree_block * rblock,int rblocklen,xfs_bmdr_block_t * dblock,int dblocklen)129 xfs_bmbt_to_bmdr(
130 	struct xfs_mount	*mp,
131 	struct xfs_btree_block	*rblock,
132 	int			rblocklen,
133 	xfs_bmdr_block_t	*dblock,
134 	int			dblocklen)
135 {
136 	int			dmxr;
137 	xfs_bmbt_key_t		*fkp;
138 	__be64			*fpp;
139 	xfs_bmbt_key_t		*tkp;
140 	__be64			*tpp;
141 
142 	if (xfs_has_crc(mp)) {
143 		ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_CRC_MAGIC));
144 		ASSERT(uuid_equal(&rblock->bb_u.l.bb_uuid,
145 		       &mp->m_sb.sb_meta_uuid));
146 		ASSERT(rblock->bb_u.l.bb_blkno ==
147 		       cpu_to_be64(XFS_BUF_DADDR_NULL));
148 	} else
149 		ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_MAGIC));
150 	ASSERT(rblock->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK));
151 	ASSERT(rblock->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK));
152 	ASSERT(rblock->bb_level != 0);
153 	dblock->bb_level = rblock->bb_level;
154 	dblock->bb_numrecs = rblock->bb_numrecs;
155 	dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
156 	fkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
157 	tkp = XFS_BMDR_KEY_ADDR(dblock, 1);
158 	fpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
159 	tpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
160 	dmxr = be16_to_cpu(dblock->bb_numrecs);
161 	memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
162 	memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
163 }
164 
165 STATIC struct xfs_btree_cur *
xfs_bmbt_dup_cursor(struct xfs_btree_cur * cur)166 xfs_bmbt_dup_cursor(
167 	struct xfs_btree_cur	*cur)
168 {
169 	struct xfs_btree_cur	*new;
170 
171 	new = xfs_bmbt_init_cursor(cur->bc_mp, cur->bc_tp,
172 			cur->bc_ino.ip, cur->bc_ino.whichfork);
173 
174 	/*
175 	 * Copy the firstblock, dfops, and flags values,
176 	 * since init cursor doesn't get them.
177 	 */
178 	new->bc_ino.flags = cur->bc_ino.flags;
179 
180 	return new;
181 }
182 
183 STATIC void
xfs_bmbt_update_cursor(struct xfs_btree_cur * src,struct xfs_btree_cur * dst)184 xfs_bmbt_update_cursor(
185 	struct xfs_btree_cur	*src,
186 	struct xfs_btree_cur	*dst)
187 {
188 	ASSERT((dst->bc_tp->t_highest_agno != NULLAGNUMBER) ||
189 	       (dst->bc_ino.ip->i_diflags & XFS_DIFLAG_REALTIME));
190 
191 	dst->bc_ino.allocated += src->bc_ino.allocated;
192 	dst->bc_tp->t_highest_agno = src->bc_tp->t_highest_agno;
193 
194 	src->bc_ino.allocated = 0;
195 }
196 
197 STATIC int
xfs_bmbt_alloc_block(struct xfs_btree_cur * cur,const union xfs_btree_ptr * start,union xfs_btree_ptr * new,int * stat)198 xfs_bmbt_alloc_block(
199 	struct xfs_btree_cur		*cur,
200 	const union xfs_btree_ptr	*start,
201 	union xfs_btree_ptr		*new,
202 	int				*stat)
203 {
204 	struct xfs_alloc_arg	args;
205 	int			error;
206 
207 	memset(&args, 0, sizeof(args));
208 	args.tp = cur->bc_tp;
209 	args.mp = cur->bc_mp;
210 	xfs_rmap_ino_bmbt_owner(&args.oinfo, cur->bc_ino.ip->i_ino,
211 			cur->bc_ino.whichfork);
212 	args.minlen = args.maxlen = args.prod = 1;
213 	args.wasdel = cur->bc_ino.flags & XFS_BTCUR_BMBT_WASDEL;
214 	if (!args.wasdel && args.tp->t_blk_res == 0)
215 		return -ENOSPC;
216 
217 	/*
218 	 * If we are coming here from something like unwritten extent
219 	 * conversion, there has been no data extent allocation already done, so
220 	 * we have to ensure that we attempt to locate the entire set of bmbt
221 	 * allocations in the same AG, as xfs_bmapi_write() would have reserved.
222 	 */
223 	if (cur->bc_tp->t_highest_agno == NULLAGNUMBER)
224 		args.minleft = xfs_bmapi_minleft(cur->bc_tp, cur->bc_ino.ip,
225 					cur->bc_ino.whichfork);
226 
227 	error = xfs_alloc_vextent_start_ag(&args, be64_to_cpu(start->l));
228 	if (error)
229 		return error;
230 
231 	if (args.fsbno == NULLFSBLOCK && args.minleft) {
232 		/*
233 		 * Could not find an AG with enough free space to satisfy
234 		 * a full btree split.  Try again and if
235 		 * successful activate the lowspace algorithm.
236 		 */
237 		args.minleft = 0;
238 		error = xfs_alloc_vextent_start_ag(&args, 0);
239 		if (error)
240 			return error;
241 		cur->bc_tp->t_flags |= XFS_TRANS_LOWMODE;
242 	}
243 	if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
244 		*stat = 0;
245 		return 0;
246 	}
247 
248 	ASSERT(args.len == 1);
249 	cur->bc_ino.allocated++;
250 	cur->bc_ino.ip->i_nblocks++;
251 	xfs_trans_log_inode(args.tp, cur->bc_ino.ip, XFS_ILOG_CORE);
252 	xfs_trans_mod_dquot_byino(args.tp, cur->bc_ino.ip,
253 			XFS_TRANS_DQ_BCOUNT, 1L);
254 
255 	new->l = cpu_to_be64(args.fsbno);
256 
257 	*stat = 1;
258 	return 0;
259 }
260 
261 STATIC int
xfs_bmbt_free_block(struct xfs_btree_cur * cur,struct xfs_buf * bp)262 xfs_bmbt_free_block(
263 	struct xfs_btree_cur	*cur,
264 	struct xfs_buf		*bp)
265 {
266 	struct xfs_mount	*mp = cur->bc_mp;
267 	struct xfs_inode	*ip = cur->bc_ino.ip;
268 	struct xfs_trans	*tp = cur->bc_tp;
269 	xfs_fsblock_t		fsbno = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
270 	struct xfs_owner_info	oinfo;
271 	int			error;
272 
273 	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, cur->bc_ino.whichfork);
274 	error = xfs_free_extent_later(cur->bc_tp, fsbno, 1, &oinfo,
275 			XFS_AG_RESV_NONE);
276 	if (error)
277 		return error;
278 
279 	ip->i_nblocks--;
280 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
281 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
282 	return 0;
283 }
284 
285 STATIC int
xfs_bmbt_get_minrecs(struct xfs_btree_cur * cur,int level)286 xfs_bmbt_get_minrecs(
287 	struct xfs_btree_cur	*cur,
288 	int			level)
289 {
290 	if (level == cur->bc_nlevels - 1) {
291 		struct xfs_ifork	*ifp;
292 
293 		ifp = xfs_ifork_ptr(cur->bc_ino.ip,
294 				    cur->bc_ino.whichfork);
295 
296 		return xfs_bmbt_maxrecs(cur->bc_mp,
297 					ifp->if_broot_bytes, level == 0) / 2;
298 	}
299 
300 	return cur->bc_mp->m_bmap_dmnr[level != 0];
301 }
302 
303 int
xfs_bmbt_get_maxrecs(struct xfs_btree_cur * cur,int level)304 xfs_bmbt_get_maxrecs(
305 	struct xfs_btree_cur	*cur,
306 	int			level)
307 {
308 	if (level == cur->bc_nlevels - 1) {
309 		struct xfs_ifork	*ifp;
310 
311 		ifp = xfs_ifork_ptr(cur->bc_ino.ip,
312 				    cur->bc_ino.whichfork);
313 
314 		return xfs_bmbt_maxrecs(cur->bc_mp,
315 					ifp->if_broot_bytes, level == 0);
316 	}
317 
318 	return cur->bc_mp->m_bmap_dmxr[level != 0];
319 
320 }
321 
322 /*
323  * Get the maximum records we could store in the on-disk format.
324  *
325  * For non-root nodes this is equivalent to xfs_bmbt_get_maxrecs, but
326  * for the root node this checks the available space in the dinode fork
327  * so that we can resize the in-memory buffer to match it.  After a
328  * resize to the maximum size this function returns the same value
329  * as xfs_bmbt_get_maxrecs for the root node, too.
330  */
331 STATIC int
xfs_bmbt_get_dmaxrecs(struct xfs_btree_cur * cur,int level)332 xfs_bmbt_get_dmaxrecs(
333 	struct xfs_btree_cur	*cur,
334 	int			level)
335 {
336 	if (level != cur->bc_nlevels - 1)
337 		return cur->bc_mp->m_bmap_dmxr[level != 0];
338 	return xfs_bmdr_maxrecs(cur->bc_ino.forksize, level == 0);
339 }
340 
341 STATIC void
xfs_bmbt_init_key_from_rec(union xfs_btree_key * key,const union xfs_btree_rec * rec)342 xfs_bmbt_init_key_from_rec(
343 	union xfs_btree_key		*key,
344 	const union xfs_btree_rec	*rec)
345 {
346 	key->bmbt.br_startoff =
347 		cpu_to_be64(xfs_bmbt_disk_get_startoff(&rec->bmbt));
348 }
349 
350 STATIC void
xfs_bmbt_init_high_key_from_rec(union xfs_btree_key * key,const union xfs_btree_rec * rec)351 xfs_bmbt_init_high_key_from_rec(
352 	union xfs_btree_key		*key,
353 	const union xfs_btree_rec	*rec)
354 {
355 	key->bmbt.br_startoff = cpu_to_be64(
356 			xfs_bmbt_disk_get_startoff(&rec->bmbt) +
357 			xfs_bmbt_disk_get_blockcount(&rec->bmbt) - 1);
358 }
359 
360 STATIC void
xfs_bmbt_init_rec_from_cur(struct xfs_btree_cur * cur,union xfs_btree_rec * rec)361 xfs_bmbt_init_rec_from_cur(
362 	struct xfs_btree_cur	*cur,
363 	union xfs_btree_rec	*rec)
364 {
365 	xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
366 }
367 
368 STATIC void
xfs_bmbt_init_ptr_from_cur(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr)369 xfs_bmbt_init_ptr_from_cur(
370 	struct xfs_btree_cur	*cur,
371 	union xfs_btree_ptr	*ptr)
372 {
373 	ptr->l = 0;
374 }
375 
376 STATIC int64_t
xfs_bmbt_key_diff(struct xfs_btree_cur * cur,const union xfs_btree_key * key)377 xfs_bmbt_key_diff(
378 	struct xfs_btree_cur		*cur,
379 	const union xfs_btree_key	*key)
380 {
381 	return (int64_t)be64_to_cpu(key->bmbt.br_startoff) -
382 				      cur->bc_rec.b.br_startoff;
383 }
384 
385 STATIC int64_t
xfs_bmbt_diff_two_keys(struct xfs_btree_cur * cur,const union xfs_btree_key * k1,const union xfs_btree_key * k2,const union xfs_btree_key * mask)386 xfs_bmbt_diff_two_keys(
387 	struct xfs_btree_cur		*cur,
388 	const union xfs_btree_key	*k1,
389 	const union xfs_btree_key	*k2,
390 	const union xfs_btree_key	*mask)
391 {
392 	uint64_t			a = be64_to_cpu(k1->bmbt.br_startoff);
393 	uint64_t			b = be64_to_cpu(k2->bmbt.br_startoff);
394 
395 	ASSERT(!mask || mask->bmbt.br_startoff);
396 
397 	/*
398 	 * Note: This routine previously casted a and b to int64 and subtracted
399 	 * them to generate a result.  This lead to problems if b was the
400 	 * "maximum" key value (all ones) being signed incorrectly, hence this
401 	 * somewhat less efficient version.
402 	 */
403 	if (a > b)
404 		return 1;
405 	if (b > a)
406 		return -1;
407 	return 0;
408 }
409 
410 static xfs_failaddr_t
xfs_bmbt_verify(struct xfs_buf * bp)411 xfs_bmbt_verify(
412 	struct xfs_buf		*bp)
413 {
414 	struct xfs_mount	*mp = bp->b_mount;
415 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
416 	xfs_failaddr_t		fa;
417 	unsigned int		level;
418 
419 	if (!xfs_verify_magic(bp, block->bb_magic))
420 		return __this_address;
421 
422 	if (xfs_has_crc(mp)) {
423 		/*
424 		 * XXX: need a better way of verifying the owner here. Right now
425 		 * just make sure there has been one set.
426 		 */
427 		fa = xfs_btree_lblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
428 		if (fa)
429 			return fa;
430 	}
431 
432 	/*
433 	 * numrecs and level verification.
434 	 *
435 	 * We don't know what fork we belong to, so just verify that the level
436 	 * is less than the maximum of the two. Later checks will be more
437 	 * precise.
438 	 */
439 	level = be16_to_cpu(block->bb_level);
440 	if (level > max(mp->m_bm_maxlevels[0], mp->m_bm_maxlevels[1]))
441 		return __this_address;
442 
443 	return xfs_btree_lblock_verify(bp, mp->m_bmap_dmxr[level != 0]);
444 }
445 
446 static void
xfs_bmbt_read_verify(struct xfs_buf * bp)447 xfs_bmbt_read_verify(
448 	struct xfs_buf	*bp)
449 {
450 	xfs_failaddr_t	fa;
451 
452 	if (!xfs_btree_lblock_verify_crc(bp))
453 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
454 	else {
455 		fa = xfs_bmbt_verify(bp);
456 		if (fa)
457 			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
458 	}
459 
460 	if (bp->b_error)
461 		trace_xfs_btree_corrupt(bp, _RET_IP_);
462 }
463 
464 static void
xfs_bmbt_write_verify(struct xfs_buf * bp)465 xfs_bmbt_write_verify(
466 	struct xfs_buf	*bp)
467 {
468 	xfs_failaddr_t	fa;
469 
470 	fa = xfs_bmbt_verify(bp);
471 	if (fa) {
472 		trace_xfs_btree_corrupt(bp, _RET_IP_);
473 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
474 		return;
475 	}
476 	xfs_btree_lblock_calc_crc(bp);
477 }
478 
479 const struct xfs_buf_ops xfs_bmbt_buf_ops = {
480 	.name = "xfs_bmbt",
481 	.magic = { cpu_to_be32(XFS_BMAP_MAGIC),
482 		   cpu_to_be32(XFS_BMAP_CRC_MAGIC) },
483 	.verify_read = xfs_bmbt_read_verify,
484 	.verify_write = xfs_bmbt_write_verify,
485 	.verify_struct = xfs_bmbt_verify,
486 };
487 
488 
489 STATIC int
xfs_bmbt_keys_inorder(struct xfs_btree_cur * cur,const union xfs_btree_key * k1,const union xfs_btree_key * k2)490 xfs_bmbt_keys_inorder(
491 	struct xfs_btree_cur		*cur,
492 	const union xfs_btree_key	*k1,
493 	const union xfs_btree_key	*k2)
494 {
495 	return be64_to_cpu(k1->bmbt.br_startoff) <
496 		be64_to_cpu(k2->bmbt.br_startoff);
497 }
498 
499 STATIC int
xfs_bmbt_recs_inorder(struct xfs_btree_cur * cur,const union xfs_btree_rec * r1,const union xfs_btree_rec * r2)500 xfs_bmbt_recs_inorder(
501 	struct xfs_btree_cur		*cur,
502 	const union xfs_btree_rec	*r1,
503 	const union xfs_btree_rec	*r2)
504 {
505 	return xfs_bmbt_disk_get_startoff(&r1->bmbt) +
506 		xfs_bmbt_disk_get_blockcount(&r1->bmbt) <=
507 		xfs_bmbt_disk_get_startoff(&r2->bmbt);
508 }
509 
510 STATIC enum xbtree_key_contig
xfs_bmbt_keys_contiguous(struct xfs_btree_cur * cur,const union xfs_btree_key * key1,const union xfs_btree_key * key2,const union xfs_btree_key * mask)511 xfs_bmbt_keys_contiguous(
512 	struct xfs_btree_cur		*cur,
513 	const union xfs_btree_key	*key1,
514 	const union xfs_btree_key	*key2,
515 	const union xfs_btree_key	*mask)
516 {
517 	ASSERT(!mask || mask->bmbt.br_startoff);
518 
519 	return xbtree_key_contig(be64_to_cpu(key1->bmbt.br_startoff),
520 				 be64_to_cpu(key2->bmbt.br_startoff));
521 }
522 
523 static const struct xfs_btree_ops xfs_bmbt_ops = {
524 	.rec_len		= sizeof(xfs_bmbt_rec_t),
525 	.key_len		= sizeof(xfs_bmbt_key_t),
526 
527 	.dup_cursor		= xfs_bmbt_dup_cursor,
528 	.update_cursor		= xfs_bmbt_update_cursor,
529 	.alloc_block		= xfs_bmbt_alloc_block,
530 	.free_block		= xfs_bmbt_free_block,
531 	.get_maxrecs		= xfs_bmbt_get_maxrecs,
532 	.get_minrecs		= xfs_bmbt_get_minrecs,
533 	.get_dmaxrecs		= xfs_bmbt_get_dmaxrecs,
534 	.init_key_from_rec	= xfs_bmbt_init_key_from_rec,
535 	.init_high_key_from_rec	= xfs_bmbt_init_high_key_from_rec,
536 	.init_rec_from_cur	= xfs_bmbt_init_rec_from_cur,
537 	.init_ptr_from_cur	= xfs_bmbt_init_ptr_from_cur,
538 	.key_diff		= xfs_bmbt_key_diff,
539 	.diff_two_keys		= xfs_bmbt_diff_two_keys,
540 	.buf_ops		= &xfs_bmbt_buf_ops,
541 	.keys_inorder		= xfs_bmbt_keys_inorder,
542 	.recs_inorder		= xfs_bmbt_recs_inorder,
543 	.keys_contiguous	= xfs_bmbt_keys_contiguous,
544 };
545 
546 /*
547  * Allocate a new bmap btree cursor.
548  */
549 struct xfs_btree_cur *				/* new bmap btree cursor */
xfs_bmbt_init_cursor(struct xfs_mount * mp,struct xfs_trans * tp,struct xfs_inode * ip,int whichfork)550 xfs_bmbt_init_cursor(
551 	struct xfs_mount	*mp,		/* file system mount point */
552 	struct xfs_trans	*tp,		/* transaction pointer */
553 	struct xfs_inode	*ip,		/* inode owning the btree */
554 	int			whichfork)	/* data or attr fork */
555 {
556 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
557 	struct xfs_btree_cur	*cur;
558 	ASSERT(whichfork != XFS_COW_FORK);
559 
560 	cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_BMAP,
561 			mp->m_bm_maxlevels[whichfork], xfs_bmbt_cur_cache);
562 	cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
563 	cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_bmbt_2);
564 
565 	cur->bc_ops = &xfs_bmbt_ops;
566 	cur->bc_flags = XFS_BTREE_LONG_PTRS | XFS_BTREE_ROOT_IN_INODE;
567 	if (xfs_has_crc(mp))
568 		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
569 
570 	cur->bc_ino.forksize = xfs_inode_fork_size(ip, whichfork);
571 	cur->bc_ino.ip = ip;
572 	cur->bc_ino.allocated = 0;
573 	cur->bc_ino.flags = 0;
574 	cur->bc_ino.whichfork = whichfork;
575 
576 	return cur;
577 }
578 
579 /* Calculate number of records in a block mapping btree block. */
580 static inline unsigned int
xfs_bmbt_block_maxrecs(unsigned int blocklen,bool leaf)581 xfs_bmbt_block_maxrecs(
582 	unsigned int		blocklen,
583 	bool			leaf)
584 {
585 	if (leaf)
586 		return blocklen / sizeof(xfs_bmbt_rec_t);
587 	return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t));
588 }
589 
590 /*
591  * Calculate number of records in a bmap btree block.
592  */
593 int
xfs_bmbt_maxrecs(struct xfs_mount * mp,int blocklen,int leaf)594 xfs_bmbt_maxrecs(
595 	struct xfs_mount	*mp,
596 	int			blocklen,
597 	int			leaf)
598 {
599 	blocklen -= XFS_BMBT_BLOCK_LEN(mp);
600 	return xfs_bmbt_block_maxrecs(blocklen, leaf);
601 }
602 
603 /*
604  * Calculate the maximum possible height of the btree that the on-disk format
605  * supports. This is used for sizing structures large enough to support every
606  * possible configuration of a filesystem that might get mounted.
607  */
608 unsigned int
xfs_bmbt_maxlevels_ondisk(void)609 xfs_bmbt_maxlevels_ondisk(void)
610 {
611 	unsigned int		minrecs[2];
612 	unsigned int		blocklen;
613 
614 	blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN,
615 		       XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN);
616 
617 	minrecs[0] = xfs_bmbt_block_maxrecs(blocklen, true) / 2;
618 	minrecs[1] = xfs_bmbt_block_maxrecs(blocklen, false) / 2;
619 
620 	/* One extra level for the inode root. */
621 	return xfs_btree_compute_maxlevels(minrecs,
622 			XFS_MAX_EXTCNT_DATA_FORK_LARGE) + 1;
623 }
624 
625 /*
626  * Calculate number of records in a bmap btree inode root.
627  */
628 int
xfs_bmdr_maxrecs(int blocklen,int leaf)629 xfs_bmdr_maxrecs(
630 	int			blocklen,
631 	int			leaf)
632 {
633 	blocklen -= sizeof(xfs_bmdr_block_t);
634 
635 	if (leaf)
636 		return blocklen / sizeof(xfs_bmdr_rec_t);
637 	return blocklen / (sizeof(xfs_bmdr_key_t) + sizeof(xfs_bmdr_ptr_t));
638 }
639 
640 /*
641  * Change the owner of a btree format fork fo the inode passed in. Change it to
642  * the owner of that is passed in so that we can change owners before or after
643  * we switch forks between inodes. The operation that the caller is doing will
644  * determine whether is needs to change owner before or after the switch.
645  *
646  * For demand paged transactional modification, the fork switch should be done
647  * after reading in all the blocks, modifying them and pinning them in the
648  * transaction. For modification when the buffers are already pinned in memory,
649  * the fork switch can be done before changing the owner as we won't need to
650  * validate the owner until the btree buffers are unpinned and writes can occur
651  * again.
652  *
653  * For recovery based ownership change, there is no transactional context and
654  * so a buffer list must be supplied so that we can record the buffers that we
655  * modified for the caller to issue IO on.
656  */
657 int
xfs_bmbt_change_owner(struct xfs_trans * tp,struct xfs_inode * ip,int whichfork,xfs_ino_t new_owner,struct list_head * buffer_list)658 xfs_bmbt_change_owner(
659 	struct xfs_trans	*tp,
660 	struct xfs_inode	*ip,
661 	int			whichfork,
662 	xfs_ino_t		new_owner,
663 	struct list_head	*buffer_list)
664 {
665 	struct xfs_btree_cur	*cur;
666 	int			error;
667 
668 	ASSERT(tp || buffer_list);
669 	ASSERT(!(tp && buffer_list));
670 	ASSERT(xfs_ifork_ptr(ip, whichfork)->if_format == XFS_DINODE_FMT_BTREE);
671 
672 	cur = xfs_bmbt_init_cursor(ip->i_mount, tp, ip, whichfork);
673 	cur->bc_ino.flags |= XFS_BTCUR_BMBT_INVALID_OWNER;
674 
675 	error = xfs_btree_change_owner(cur, new_owner, buffer_list);
676 	xfs_btree_del_cursor(cur, error);
677 	return error;
678 }
679 
680 /* Calculate the bmap btree size for some records. */
681 unsigned long long
xfs_bmbt_calc_size(struct xfs_mount * mp,unsigned long long len)682 xfs_bmbt_calc_size(
683 	struct xfs_mount	*mp,
684 	unsigned long long	len)
685 {
686 	return xfs_btree_calc_size(mp->m_bmap_dmnr, len);
687 }
688 
689 int __init
xfs_bmbt_init_cur_cache(void)690 xfs_bmbt_init_cur_cache(void)
691 {
692 	xfs_bmbt_cur_cache = kmem_cache_create("xfs_bmbt_cur",
693 			xfs_btree_cur_sizeof(xfs_bmbt_maxlevels_ondisk()),
694 			0, 0, NULL);
695 
696 	if (!xfs_bmbt_cur_cache)
697 		return -ENOMEM;
698 	return 0;
699 }
700 
701 void
xfs_bmbt_destroy_cur_cache(void)702 xfs_bmbt_destroy_cur_cache(void)
703 {
704 	kmem_cache_destroy(xfs_bmbt_cur_cache);
705 	xfs_bmbt_cur_cache = NULL;
706 }
707