1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * Copyright (c) 2013 Red Hat, Inc.
5  * All Rights Reserved.
6  */
7 #include "xfs.h"
8 #include "xfs_fs.h"
9 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_bit.h"
14 #include "xfs_mount.h"
15 #include "xfs_inode.h"
16 #include "xfs_dir2.h"
17 #include "xfs_dir2_priv.h"
18 #include "xfs_trans.h"
19 #include "xfs_bmap.h"
20 #include "xfs_attr_leaf.h"
21 #include "xfs_error.h"
22 #include "xfs_trace.h"
23 #include "xfs_buf_item.h"
24 #include "xfs_log.h"
25 #include "xfs_errortag.h"
26 
27 /*
28  * xfs_da_btree.c
29  *
30  * Routines to implement directories as Btrees of hashed names.
31  */
32 
33 /*========================================================================
34  * Function prototypes for the kernel.
35  *========================================================================*/
36 
37 /*
38  * Routines used for growing the Btree.
39  */
40 STATIC int xfs_da3_root_split(xfs_da_state_t *state,
41 					    xfs_da_state_blk_t *existing_root,
42 					    xfs_da_state_blk_t *new_child);
43 STATIC int xfs_da3_node_split(xfs_da_state_t *state,
44 					    xfs_da_state_blk_t *existing_blk,
45 					    xfs_da_state_blk_t *split_blk,
46 					    xfs_da_state_blk_t *blk_to_add,
47 					    int treelevel,
48 					    int *result);
49 STATIC void xfs_da3_node_rebalance(xfs_da_state_t *state,
50 					 xfs_da_state_blk_t *node_blk_1,
51 					 xfs_da_state_blk_t *node_blk_2);
52 STATIC void xfs_da3_node_add(xfs_da_state_t *state,
53 				   xfs_da_state_blk_t *old_node_blk,
54 				   xfs_da_state_blk_t *new_node_blk);
55 
56 /*
57  * Routines used for shrinking the Btree.
58  */
59 STATIC int xfs_da3_root_join(xfs_da_state_t *state,
60 					   xfs_da_state_blk_t *root_blk);
61 STATIC int xfs_da3_node_toosmall(xfs_da_state_t *state, int *retval);
62 STATIC void xfs_da3_node_remove(xfs_da_state_t *state,
63 					      xfs_da_state_blk_t *drop_blk);
64 STATIC void xfs_da3_node_unbalance(xfs_da_state_t *state,
65 					 xfs_da_state_blk_t *src_node_blk,
66 					 xfs_da_state_blk_t *dst_node_blk);
67 
68 /*
69  * Utility routines.
70  */
71 STATIC int	xfs_da3_blk_unlink(xfs_da_state_t *state,
72 				  xfs_da_state_blk_t *drop_blk,
73 				  xfs_da_state_blk_t *save_blk);
74 
75 
76 struct kmem_cache	*xfs_da_state_cache;	/* anchor for dir/attr state */
77 
78 /*
79  * Allocate a dir-state structure.
80  * We don't put them on the stack since they're large.
81  */
82 struct xfs_da_state *
xfs_da_state_alloc(struct xfs_da_args * args)83 xfs_da_state_alloc(
84 	struct xfs_da_args	*args)
85 {
86 	struct xfs_da_state	*state;
87 
88 	state = kmem_cache_zalloc(xfs_da_state_cache, GFP_NOFS | __GFP_NOFAIL);
89 	state->args = args;
90 	state->mp = args->dp->i_mount;
91 	return state;
92 }
93 
94 /*
95  * Kill the altpath contents of a da-state structure.
96  */
97 STATIC void
xfs_da_state_kill_altpath(xfs_da_state_t * state)98 xfs_da_state_kill_altpath(xfs_da_state_t *state)
99 {
100 	int	i;
101 
102 	for (i = 0; i < state->altpath.active; i++)
103 		state->altpath.blk[i].bp = NULL;
104 	state->altpath.active = 0;
105 }
106 
107 /*
108  * Free a da-state structure.
109  */
110 void
xfs_da_state_free(xfs_da_state_t * state)111 xfs_da_state_free(xfs_da_state_t *state)
112 {
113 	xfs_da_state_kill_altpath(state);
114 #ifdef DEBUG
115 	memset((char *)state, 0, sizeof(*state));
116 #endif /* DEBUG */
117 	kmem_cache_free(xfs_da_state_cache, state);
118 }
119 
120 void
xfs_da_state_reset(struct xfs_da_state * state,struct xfs_da_args * args)121 xfs_da_state_reset(
122 	struct xfs_da_state	*state,
123 	struct xfs_da_args	*args)
124 {
125 	xfs_da_state_kill_altpath(state);
126 	memset(state, 0, sizeof(struct xfs_da_state));
127 	state->args = args;
128 	state->mp = state->args->dp->i_mount;
129 }
130 
xfs_dabuf_nfsb(struct xfs_mount * mp,int whichfork)131 static inline int xfs_dabuf_nfsb(struct xfs_mount *mp, int whichfork)
132 {
133 	if (whichfork == XFS_DATA_FORK)
134 		return mp->m_dir_geo->fsbcount;
135 	return mp->m_attr_geo->fsbcount;
136 }
137 
138 void
xfs_da3_node_hdr_from_disk(struct xfs_mount * mp,struct xfs_da3_icnode_hdr * to,struct xfs_da_intnode * from)139 xfs_da3_node_hdr_from_disk(
140 	struct xfs_mount		*mp,
141 	struct xfs_da3_icnode_hdr	*to,
142 	struct xfs_da_intnode		*from)
143 {
144 	if (xfs_has_crc(mp)) {
145 		struct xfs_da3_intnode	*from3 = (struct xfs_da3_intnode *)from;
146 
147 		to->forw = be32_to_cpu(from3->hdr.info.hdr.forw);
148 		to->back = be32_to_cpu(from3->hdr.info.hdr.back);
149 		to->magic = be16_to_cpu(from3->hdr.info.hdr.magic);
150 		to->count = be16_to_cpu(from3->hdr.__count);
151 		to->level = be16_to_cpu(from3->hdr.__level);
152 		to->btree = from3->__btree;
153 		ASSERT(to->magic == XFS_DA3_NODE_MAGIC);
154 	} else {
155 		to->forw = be32_to_cpu(from->hdr.info.forw);
156 		to->back = be32_to_cpu(from->hdr.info.back);
157 		to->magic = be16_to_cpu(from->hdr.info.magic);
158 		to->count = be16_to_cpu(from->hdr.__count);
159 		to->level = be16_to_cpu(from->hdr.__level);
160 		to->btree = from->__btree;
161 		ASSERT(to->magic == XFS_DA_NODE_MAGIC);
162 	}
163 }
164 
165 void
xfs_da3_node_hdr_to_disk(struct xfs_mount * mp,struct xfs_da_intnode * to,struct xfs_da3_icnode_hdr * from)166 xfs_da3_node_hdr_to_disk(
167 	struct xfs_mount		*mp,
168 	struct xfs_da_intnode		*to,
169 	struct xfs_da3_icnode_hdr	*from)
170 {
171 	if (xfs_has_crc(mp)) {
172 		struct xfs_da3_intnode	*to3 = (struct xfs_da3_intnode *)to;
173 
174 		ASSERT(from->magic == XFS_DA3_NODE_MAGIC);
175 		to3->hdr.info.hdr.forw = cpu_to_be32(from->forw);
176 		to3->hdr.info.hdr.back = cpu_to_be32(from->back);
177 		to3->hdr.info.hdr.magic = cpu_to_be16(from->magic);
178 		to3->hdr.__count = cpu_to_be16(from->count);
179 		to3->hdr.__level = cpu_to_be16(from->level);
180 	} else {
181 		ASSERT(from->magic == XFS_DA_NODE_MAGIC);
182 		to->hdr.info.forw = cpu_to_be32(from->forw);
183 		to->hdr.info.back = cpu_to_be32(from->back);
184 		to->hdr.info.magic = cpu_to_be16(from->magic);
185 		to->hdr.__count = cpu_to_be16(from->count);
186 		to->hdr.__level = cpu_to_be16(from->level);
187 	}
188 }
189 
190 /*
191  * Verify an xfs_da3_blkinfo structure. Note that the da3 fields are only
192  * accessible on v5 filesystems. This header format is common across da node,
193  * attr leaf and dir leaf blocks.
194  */
195 xfs_failaddr_t
xfs_da3_blkinfo_verify(struct xfs_buf * bp,struct xfs_da3_blkinfo * hdr3)196 xfs_da3_blkinfo_verify(
197 	struct xfs_buf		*bp,
198 	struct xfs_da3_blkinfo	*hdr3)
199 {
200 	struct xfs_mount	*mp = bp->b_mount;
201 	struct xfs_da_blkinfo	*hdr = &hdr3->hdr;
202 
203 	if (!xfs_verify_magic16(bp, hdr->magic))
204 		return __this_address;
205 
206 	if (xfs_has_crc(mp)) {
207 		if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
208 			return __this_address;
209 		if (be64_to_cpu(hdr3->blkno) != xfs_buf_daddr(bp))
210 			return __this_address;
211 		if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
212 			return __this_address;
213 	}
214 
215 	return NULL;
216 }
217 
218 static xfs_failaddr_t
xfs_da3_node_verify(struct xfs_buf * bp)219 xfs_da3_node_verify(
220 	struct xfs_buf		*bp)
221 {
222 	struct xfs_mount	*mp = bp->b_mount;
223 	struct xfs_da_intnode	*hdr = bp->b_addr;
224 	struct xfs_da3_icnode_hdr ichdr;
225 	xfs_failaddr_t		fa;
226 
227 	xfs_da3_node_hdr_from_disk(mp, &ichdr, hdr);
228 
229 	fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
230 	if (fa)
231 		return fa;
232 
233 	if (ichdr.level == 0)
234 		return __this_address;
235 	if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
236 		return __this_address;
237 	if (ichdr.count == 0)
238 		return __this_address;
239 
240 	/*
241 	 * we don't know if the node is for and attribute or directory tree,
242 	 * so only fail if the count is outside both bounds
243 	 */
244 	if (ichdr.count > mp->m_dir_geo->node_ents &&
245 	    ichdr.count > mp->m_attr_geo->node_ents)
246 		return __this_address;
247 
248 	/* XXX: hash order check? */
249 
250 	return NULL;
251 }
252 
253 static void
xfs_da3_node_write_verify(struct xfs_buf * bp)254 xfs_da3_node_write_verify(
255 	struct xfs_buf	*bp)
256 {
257 	struct xfs_mount	*mp = bp->b_mount;
258 	struct xfs_buf_log_item	*bip = bp->b_log_item;
259 	struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
260 	xfs_failaddr_t		fa;
261 
262 	fa = xfs_da3_node_verify(bp);
263 	if (fa) {
264 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
265 		return;
266 	}
267 
268 	if (!xfs_has_crc(mp))
269 		return;
270 
271 	if (bip)
272 		hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
273 
274 	xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
275 }
276 
277 /*
278  * leaf/node format detection on trees is sketchy, so a node read can be done on
279  * leaf level blocks when detection identifies the tree as a node format tree
280  * incorrectly. In this case, we need to swap the verifier to match the correct
281  * format of the block being read.
282  */
283 static void
xfs_da3_node_read_verify(struct xfs_buf * bp)284 xfs_da3_node_read_verify(
285 	struct xfs_buf		*bp)
286 {
287 	struct xfs_da_blkinfo	*info = bp->b_addr;
288 	xfs_failaddr_t		fa;
289 
290 	switch (be16_to_cpu(info->magic)) {
291 		case XFS_DA3_NODE_MAGIC:
292 			if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
293 				xfs_verifier_error(bp, -EFSBADCRC,
294 						__this_address);
295 				break;
296 			}
297 			fallthrough;
298 		case XFS_DA_NODE_MAGIC:
299 			fa = xfs_da3_node_verify(bp);
300 			if (fa)
301 				xfs_verifier_error(bp, -EFSCORRUPTED, fa);
302 			return;
303 		case XFS_ATTR_LEAF_MAGIC:
304 		case XFS_ATTR3_LEAF_MAGIC:
305 			bp->b_ops = &xfs_attr3_leaf_buf_ops;
306 			bp->b_ops->verify_read(bp);
307 			return;
308 		case XFS_DIR2_LEAFN_MAGIC:
309 		case XFS_DIR3_LEAFN_MAGIC:
310 			bp->b_ops = &xfs_dir3_leafn_buf_ops;
311 			bp->b_ops->verify_read(bp);
312 			return;
313 		default:
314 			xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
315 			break;
316 	}
317 }
318 
319 /* Verify the structure of a da3 block. */
320 static xfs_failaddr_t
xfs_da3_node_verify_struct(struct xfs_buf * bp)321 xfs_da3_node_verify_struct(
322 	struct xfs_buf		*bp)
323 {
324 	struct xfs_da_blkinfo	*info = bp->b_addr;
325 
326 	switch (be16_to_cpu(info->magic)) {
327 	case XFS_DA3_NODE_MAGIC:
328 	case XFS_DA_NODE_MAGIC:
329 		return xfs_da3_node_verify(bp);
330 	case XFS_ATTR_LEAF_MAGIC:
331 	case XFS_ATTR3_LEAF_MAGIC:
332 		bp->b_ops = &xfs_attr3_leaf_buf_ops;
333 		return bp->b_ops->verify_struct(bp);
334 	case XFS_DIR2_LEAFN_MAGIC:
335 	case XFS_DIR3_LEAFN_MAGIC:
336 		bp->b_ops = &xfs_dir3_leafn_buf_ops;
337 		return bp->b_ops->verify_struct(bp);
338 	default:
339 		return __this_address;
340 	}
341 }
342 
343 const struct xfs_buf_ops xfs_da3_node_buf_ops = {
344 	.name = "xfs_da3_node",
345 	.magic16 = { cpu_to_be16(XFS_DA_NODE_MAGIC),
346 		     cpu_to_be16(XFS_DA3_NODE_MAGIC) },
347 	.verify_read = xfs_da3_node_read_verify,
348 	.verify_write = xfs_da3_node_write_verify,
349 	.verify_struct = xfs_da3_node_verify_struct,
350 };
351 
352 static int
xfs_da3_node_set_type(struct xfs_trans * tp,struct xfs_buf * bp)353 xfs_da3_node_set_type(
354 	struct xfs_trans	*tp,
355 	struct xfs_buf		*bp)
356 {
357 	struct xfs_da_blkinfo	*info = bp->b_addr;
358 
359 	switch (be16_to_cpu(info->magic)) {
360 	case XFS_DA_NODE_MAGIC:
361 	case XFS_DA3_NODE_MAGIC:
362 		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
363 		return 0;
364 	case XFS_ATTR_LEAF_MAGIC:
365 	case XFS_ATTR3_LEAF_MAGIC:
366 		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_ATTR_LEAF_BUF);
367 		return 0;
368 	case XFS_DIR2_LEAFN_MAGIC:
369 	case XFS_DIR3_LEAFN_MAGIC:
370 		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
371 		return 0;
372 	default:
373 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, tp->t_mountp,
374 				info, sizeof(*info));
375 		xfs_trans_brelse(tp, bp);
376 		return -EFSCORRUPTED;
377 	}
378 }
379 
380 int
xfs_da3_node_read(struct xfs_trans * tp,struct xfs_inode * dp,xfs_dablk_t bno,struct xfs_buf ** bpp,int whichfork)381 xfs_da3_node_read(
382 	struct xfs_trans	*tp,
383 	struct xfs_inode	*dp,
384 	xfs_dablk_t		bno,
385 	struct xfs_buf		**bpp,
386 	int			whichfork)
387 {
388 	int			error;
389 
390 	error = xfs_da_read_buf(tp, dp, bno, 0, bpp, whichfork,
391 			&xfs_da3_node_buf_ops);
392 	if (error || !*bpp || !tp)
393 		return error;
394 	return xfs_da3_node_set_type(tp, *bpp);
395 }
396 
397 int
xfs_da3_node_read_mapped(struct xfs_trans * tp,struct xfs_inode * dp,xfs_daddr_t mappedbno,struct xfs_buf ** bpp,int whichfork)398 xfs_da3_node_read_mapped(
399 	struct xfs_trans	*tp,
400 	struct xfs_inode	*dp,
401 	xfs_daddr_t		mappedbno,
402 	struct xfs_buf		**bpp,
403 	int			whichfork)
404 {
405 	struct xfs_mount	*mp = dp->i_mount;
406 	int			error;
407 
408 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, mappedbno,
409 			XFS_FSB_TO_BB(mp, xfs_dabuf_nfsb(mp, whichfork)), 0,
410 			bpp, &xfs_da3_node_buf_ops);
411 	if (error || !*bpp)
412 		return error;
413 
414 	if (whichfork == XFS_ATTR_FORK)
415 		xfs_buf_set_ref(*bpp, XFS_ATTR_BTREE_REF);
416 	else
417 		xfs_buf_set_ref(*bpp, XFS_DIR_BTREE_REF);
418 
419 	if (!tp)
420 		return 0;
421 	return xfs_da3_node_set_type(tp, *bpp);
422 }
423 
424 /*========================================================================
425  * Routines used for growing the Btree.
426  *========================================================================*/
427 
428 /*
429  * Create the initial contents of an intermediate node.
430  */
431 int
xfs_da3_node_create(struct xfs_da_args * args,xfs_dablk_t blkno,int level,struct xfs_buf ** bpp,int whichfork)432 xfs_da3_node_create(
433 	struct xfs_da_args	*args,
434 	xfs_dablk_t		blkno,
435 	int			level,
436 	struct xfs_buf		**bpp,
437 	int			whichfork)
438 {
439 	struct xfs_da_intnode	*node;
440 	struct xfs_trans	*tp = args->trans;
441 	struct xfs_mount	*mp = tp->t_mountp;
442 	struct xfs_da3_icnode_hdr ichdr = {0};
443 	struct xfs_buf		*bp;
444 	int			error;
445 	struct xfs_inode	*dp = args->dp;
446 
447 	trace_xfs_da_node_create(args);
448 	ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
449 
450 	error = xfs_da_get_buf(tp, dp, blkno, &bp, whichfork);
451 	if (error)
452 		return error;
453 	bp->b_ops = &xfs_da3_node_buf_ops;
454 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
455 	node = bp->b_addr;
456 
457 	if (xfs_has_crc(mp)) {
458 		struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
459 
460 		memset(hdr3, 0, sizeof(struct xfs_da3_node_hdr));
461 		ichdr.magic = XFS_DA3_NODE_MAGIC;
462 		hdr3->info.blkno = cpu_to_be64(xfs_buf_daddr(bp));
463 		hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
464 		uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid);
465 	} else {
466 		ichdr.magic = XFS_DA_NODE_MAGIC;
467 	}
468 	ichdr.level = level;
469 
470 	xfs_da3_node_hdr_to_disk(dp->i_mount, node, &ichdr);
471 	xfs_trans_log_buf(tp, bp,
472 		XFS_DA_LOGRANGE(node, &node->hdr, args->geo->node_hdr_size));
473 
474 	*bpp = bp;
475 	return 0;
476 }
477 
478 /*
479  * Split a leaf node, rebalance, then possibly split
480  * intermediate nodes, rebalance, etc.
481  */
482 int							/* error */
xfs_da3_split(struct xfs_da_state * state)483 xfs_da3_split(
484 	struct xfs_da_state	*state)
485 {
486 	struct xfs_da_state_blk	*oldblk;
487 	struct xfs_da_state_blk	*newblk;
488 	struct xfs_da_state_blk	*addblk;
489 	struct xfs_da_intnode	*node;
490 	int			max;
491 	int			action = 0;
492 	int			error;
493 	int			i;
494 
495 	trace_xfs_da_split(state->args);
496 
497 	if (XFS_TEST_ERROR(false, state->mp, XFS_ERRTAG_DA_LEAF_SPLIT))
498 		return -EIO;
499 
500 	/*
501 	 * Walk back up the tree splitting/inserting/adjusting as necessary.
502 	 * If we need to insert and there isn't room, split the node, then
503 	 * decide which fragment to insert the new block from below into.
504 	 * Note that we may split the root this way, but we need more fixup.
505 	 */
506 	max = state->path.active - 1;
507 	ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
508 	ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
509 	       state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
510 
511 	addblk = &state->path.blk[max];		/* initial dummy value */
512 	for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
513 		oldblk = &state->path.blk[i];
514 		newblk = &state->altpath.blk[i];
515 
516 		/*
517 		 * If a leaf node then
518 		 *     Allocate a new leaf node, then rebalance across them.
519 		 * else if an intermediate node then
520 		 *     We split on the last layer, must we split the node?
521 		 */
522 		switch (oldblk->magic) {
523 		case XFS_ATTR_LEAF_MAGIC:
524 			error = xfs_attr3_leaf_split(state, oldblk, newblk);
525 			if ((error != 0) && (error != -ENOSPC)) {
526 				return error;	/* GROT: attr is inconsistent */
527 			}
528 			if (!error) {
529 				addblk = newblk;
530 				break;
531 			}
532 			/*
533 			 * Entry wouldn't fit, split the leaf again. The new
534 			 * extrablk will be consumed by xfs_da3_node_split if
535 			 * the node is split.
536 			 */
537 			state->extravalid = 1;
538 			if (state->inleaf) {
539 				state->extraafter = 0;	/* before newblk */
540 				trace_xfs_attr_leaf_split_before(state->args);
541 				error = xfs_attr3_leaf_split(state, oldblk,
542 							    &state->extrablk);
543 			} else {
544 				state->extraafter = 1;	/* after newblk */
545 				trace_xfs_attr_leaf_split_after(state->args);
546 				error = xfs_attr3_leaf_split(state, newblk,
547 							    &state->extrablk);
548 			}
549 			if (error)
550 				return error;	/* GROT: attr inconsistent */
551 			addblk = newblk;
552 			break;
553 		case XFS_DIR2_LEAFN_MAGIC:
554 			error = xfs_dir2_leafn_split(state, oldblk, newblk);
555 			if (error)
556 				return error;
557 			addblk = newblk;
558 			break;
559 		case XFS_DA_NODE_MAGIC:
560 			error = xfs_da3_node_split(state, oldblk, newblk, addblk,
561 							 max - i, &action);
562 			addblk->bp = NULL;
563 			if (error)
564 				return error;	/* GROT: dir is inconsistent */
565 			/*
566 			 * Record the newly split block for the next time thru?
567 			 */
568 			if (action)
569 				addblk = newblk;
570 			else
571 				addblk = NULL;
572 			break;
573 		}
574 
575 		/*
576 		 * Update the btree to show the new hashval for this child.
577 		 */
578 		xfs_da3_fixhashpath(state, &state->path);
579 	}
580 	if (!addblk)
581 		return 0;
582 
583 	/*
584 	 * xfs_da3_node_split() should have consumed any extra blocks we added
585 	 * during a double leaf split in the attr fork. This is guaranteed as
586 	 * we can't be here if the attr fork only has a single leaf block.
587 	 */
588 	ASSERT(state->extravalid == 0 ||
589 	       state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
590 
591 	/*
592 	 * Split the root node.
593 	 */
594 	ASSERT(state->path.active == 0);
595 	oldblk = &state->path.blk[0];
596 	error = xfs_da3_root_split(state, oldblk, addblk);
597 	if (error)
598 		goto out;
599 
600 	/*
601 	 * Update pointers to the node which used to be block 0 and just got
602 	 * bumped because of the addition of a new root node.  Note that the
603 	 * original block 0 could be at any position in the list of blocks in
604 	 * the tree.
605 	 *
606 	 * Note: the magic numbers and sibling pointers are in the same physical
607 	 * place for both v2 and v3 headers (by design). Hence it doesn't matter
608 	 * which version of the xfs_da_intnode structure we use here as the
609 	 * result will be the same using either structure.
610 	 */
611 	node = oldblk->bp->b_addr;
612 	if (node->hdr.info.forw) {
613 		if (be32_to_cpu(node->hdr.info.forw) != addblk->blkno) {
614 			xfs_buf_mark_corrupt(oldblk->bp);
615 			error = -EFSCORRUPTED;
616 			goto out;
617 		}
618 		node = addblk->bp->b_addr;
619 		node->hdr.info.back = cpu_to_be32(oldblk->blkno);
620 		xfs_trans_log_buf(state->args->trans, addblk->bp,
621 				  XFS_DA_LOGRANGE(node, &node->hdr.info,
622 				  sizeof(node->hdr.info)));
623 	}
624 	node = oldblk->bp->b_addr;
625 	if (node->hdr.info.back) {
626 		if (be32_to_cpu(node->hdr.info.back) != addblk->blkno) {
627 			xfs_buf_mark_corrupt(oldblk->bp);
628 			error = -EFSCORRUPTED;
629 			goto out;
630 		}
631 		node = addblk->bp->b_addr;
632 		node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
633 		xfs_trans_log_buf(state->args->trans, addblk->bp,
634 				  XFS_DA_LOGRANGE(node, &node->hdr.info,
635 				  sizeof(node->hdr.info)));
636 	}
637 out:
638 	addblk->bp = NULL;
639 	return error;
640 }
641 
642 /*
643  * Split the root.  We have to create a new root and point to the two
644  * parts (the split old root) that we just created.  Copy block zero to
645  * the EOF, extending the inode in process.
646  */
647 STATIC int						/* error */
xfs_da3_root_split(struct xfs_da_state * state,struct xfs_da_state_blk * blk1,struct xfs_da_state_blk * blk2)648 xfs_da3_root_split(
649 	struct xfs_da_state	*state,
650 	struct xfs_da_state_blk	*blk1,
651 	struct xfs_da_state_blk	*blk2)
652 {
653 	struct xfs_da_intnode	*node;
654 	struct xfs_da_intnode	*oldroot;
655 	struct xfs_da_node_entry *btree;
656 	struct xfs_da3_icnode_hdr nodehdr;
657 	struct xfs_da_args	*args;
658 	struct xfs_buf		*bp;
659 	struct xfs_inode	*dp;
660 	struct xfs_trans	*tp;
661 	struct xfs_dir2_leaf	*leaf;
662 	xfs_dablk_t		blkno;
663 	int			level;
664 	int			error;
665 	int			size;
666 
667 	trace_xfs_da_root_split(state->args);
668 
669 	/*
670 	 * Copy the existing (incorrect) block from the root node position
671 	 * to a free space somewhere.
672 	 */
673 	args = state->args;
674 	error = xfs_da_grow_inode(args, &blkno);
675 	if (error)
676 		return error;
677 
678 	dp = args->dp;
679 	tp = args->trans;
680 	error = xfs_da_get_buf(tp, dp, blkno, &bp, args->whichfork);
681 	if (error)
682 		return error;
683 	node = bp->b_addr;
684 	oldroot = blk1->bp->b_addr;
685 	if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
686 	    oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
687 		struct xfs_da3_icnode_hdr icnodehdr;
688 
689 		xfs_da3_node_hdr_from_disk(dp->i_mount, &icnodehdr, oldroot);
690 		btree = icnodehdr.btree;
691 		size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
692 		level = icnodehdr.level;
693 
694 		/*
695 		 * we are about to copy oldroot to bp, so set up the type
696 		 * of bp while we know exactly what it will be.
697 		 */
698 		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
699 	} else {
700 		struct xfs_dir3_icleaf_hdr leafhdr;
701 
702 		leaf = (xfs_dir2_leaf_t *)oldroot;
703 		xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr, leaf);
704 
705 		ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
706 		       leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
707 		size = (int)((char *)&leafhdr.ents[leafhdr.count] -
708 			(char *)leaf);
709 		level = 0;
710 
711 		/*
712 		 * we are about to copy oldroot to bp, so set up the type
713 		 * of bp while we know exactly what it will be.
714 		 */
715 		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
716 	}
717 
718 	/*
719 	 * we can copy most of the information in the node from one block to
720 	 * another, but for CRC enabled headers we have to make sure that the
721 	 * block specific identifiers are kept intact. We update the buffer
722 	 * directly for this.
723 	 */
724 	memcpy(node, oldroot, size);
725 	if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
726 	    oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
727 		struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
728 
729 		node3->hdr.info.blkno = cpu_to_be64(xfs_buf_daddr(bp));
730 	}
731 	xfs_trans_log_buf(tp, bp, 0, size - 1);
732 
733 	bp->b_ops = blk1->bp->b_ops;
734 	xfs_trans_buf_copy_type(bp, blk1->bp);
735 	blk1->bp = bp;
736 	blk1->blkno = blkno;
737 
738 	/*
739 	 * Set up the new root node.
740 	 */
741 	error = xfs_da3_node_create(args,
742 		(args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
743 		level + 1, &bp, args->whichfork);
744 	if (error)
745 		return error;
746 
747 	node = bp->b_addr;
748 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
749 	btree = nodehdr.btree;
750 	btree[0].hashval = cpu_to_be32(blk1->hashval);
751 	btree[0].before = cpu_to_be32(blk1->blkno);
752 	btree[1].hashval = cpu_to_be32(blk2->hashval);
753 	btree[1].before = cpu_to_be32(blk2->blkno);
754 	nodehdr.count = 2;
755 	xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
756 
757 #ifdef DEBUG
758 	if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
759 	    oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
760 		ASSERT(blk1->blkno >= args->geo->leafblk &&
761 		       blk1->blkno < args->geo->freeblk);
762 		ASSERT(blk2->blkno >= args->geo->leafblk &&
763 		       blk2->blkno < args->geo->freeblk);
764 	}
765 #endif
766 
767 	/* Header is already logged by xfs_da_node_create */
768 	xfs_trans_log_buf(tp, bp,
769 		XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
770 
771 	return 0;
772 }
773 
774 /*
775  * Split the node, rebalance, then add the new entry.
776  */
777 STATIC int						/* error */
xfs_da3_node_split(struct xfs_da_state * state,struct xfs_da_state_blk * oldblk,struct xfs_da_state_blk * newblk,struct xfs_da_state_blk * addblk,int treelevel,int * result)778 xfs_da3_node_split(
779 	struct xfs_da_state	*state,
780 	struct xfs_da_state_blk	*oldblk,
781 	struct xfs_da_state_blk	*newblk,
782 	struct xfs_da_state_blk	*addblk,
783 	int			treelevel,
784 	int			*result)
785 {
786 	struct xfs_da_intnode	*node;
787 	struct xfs_da3_icnode_hdr nodehdr;
788 	xfs_dablk_t		blkno;
789 	int			newcount;
790 	int			error;
791 	int			useextra;
792 	struct xfs_inode	*dp = state->args->dp;
793 
794 	trace_xfs_da_node_split(state->args);
795 
796 	node = oldblk->bp->b_addr;
797 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
798 
799 	/*
800 	 * With V2 dirs the extra block is data or freespace.
801 	 */
802 	useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
803 	newcount = 1 + useextra;
804 	/*
805 	 * Do we have to split the node?
806 	 */
807 	if (nodehdr.count + newcount > state->args->geo->node_ents) {
808 		/*
809 		 * Allocate a new node, add to the doubly linked chain of
810 		 * nodes, then move some of our excess entries into it.
811 		 */
812 		error = xfs_da_grow_inode(state->args, &blkno);
813 		if (error)
814 			return error;	/* GROT: dir is inconsistent */
815 
816 		error = xfs_da3_node_create(state->args, blkno, treelevel,
817 					   &newblk->bp, state->args->whichfork);
818 		if (error)
819 			return error;	/* GROT: dir is inconsistent */
820 		newblk->blkno = blkno;
821 		newblk->magic = XFS_DA_NODE_MAGIC;
822 		xfs_da3_node_rebalance(state, oldblk, newblk);
823 		error = xfs_da3_blk_link(state, oldblk, newblk);
824 		if (error)
825 			return error;
826 		*result = 1;
827 	} else {
828 		*result = 0;
829 	}
830 
831 	/*
832 	 * Insert the new entry(s) into the correct block
833 	 * (updating last hashval in the process).
834 	 *
835 	 * xfs_da3_node_add() inserts BEFORE the given index,
836 	 * and as a result of using node_lookup_int() we always
837 	 * point to a valid entry (not after one), but a split
838 	 * operation always results in a new block whose hashvals
839 	 * FOLLOW the current block.
840 	 *
841 	 * If we had double-split op below us, then add the extra block too.
842 	 */
843 	node = oldblk->bp->b_addr;
844 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
845 	if (oldblk->index <= nodehdr.count) {
846 		oldblk->index++;
847 		xfs_da3_node_add(state, oldblk, addblk);
848 		if (useextra) {
849 			if (state->extraafter)
850 				oldblk->index++;
851 			xfs_da3_node_add(state, oldblk, &state->extrablk);
852 			state->extravalid = 0;
853 		}
854 	} else {
855 		newblk->index++;
856 		xfs_da3_node_add(state, newblk, addblk);
857 		if (useextra) {
858 			if (state->extraafter)
859 				newblk->index++;
860 			xfs_da3_node_add(state, newblk, &state->extrablk);
861 			state->extravalid = 0;
862 		}
863 	}
864 
865 	return 0;
866 }
867 
868 /*
869  * Balance the btree elements between two intermediate nodes,
870  * usually one full and one empty.
871  *
872  * NOTE: if blk2 is empty, then it will get the upper half of blk1.
873  */
874 STATIC void
xfs_da3_node_rebalance(struct xfs_da_state * state,struct xfs_da_state_blk * blk1,struct xfs_da_state_blk * blk2)875 xfs_da3_node_rebalance(
876 	struct xfs_da_state	*state,
877 	struct xfs_da_state_blk	*blk1,
878 	struct xfs_da_state_blk	*blk2)
879 {
880 	struct xfs_da_intnode	*node1;
881 	struct xfs_da_intnode	*node2;
882 	struct xfs_da_node_entry *btree1;
883 	struct xfs_da_node_entry *btree2;
884 	struct xfs_da_node_entry *btree_s;
885 	struct xfs_da_node_entry *btree_d;
886 	struct xfs_da3_icnode_hdr nodehdr1;
887 	struct xfs_da3_icnode_hdr nodehdr2;
888 	struct xfs_trans	*tp;
889 	int			count;
890 	int			tmp;
891 	int			swap = 0;
892 	struct xfs_inode	*dp = state->args->dp;
893 
894 	trace_xfs_da_node_rebalance(state->args);
895 
896 	node1 = blk1->bp->b_addr;
897 	node2 = blk2->bp->b_addr;
898 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
899 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
900 	btree1 = nodehdr1.btree;
901 	btree2 = nodehdr2.btree;
902 
903 	/*
904 	 * Figure out how many entries need to move, and in which direction.
905 	 * Swap the nodes around if that makes it simpler.
906 	 */
907 	if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
908 	    ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
909 	     (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
910 			be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
911 		swap(node1, node2);
912 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
913 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
914 		btree1 = nodehdr1.btree;
915 		btree2 = nodehdr2.btree;
916 		swap = 1;
917 	}
918 
919 	count = (nodehdr1.count - nodehdr2.count) / 2;
920 	if (count == 0)
921 		return;
922 	tp = state->args->trans;
923 	/*
924 	 * Two cases: high-to-low and low-to-high.
925 	 */
926 	if (count > 0) {
927 		/*
928 		 * Move elements in node2 up to make a hole.
929 		 */
930 		tmp = nodehdr2.count;
931 		if (tmp > 0) {
932 			tmp *= (uint)sizeof(xfs_da_node_entry_t);
933 			btree_s = &btree2[0];
934 			btree_d = &btree2[count];
935 			memmove(btree_d, btree_s, tmp);
936 		}
937 
938 		/*
939 		 * Move the req'd B-tree elements from high in node1 to
940 		 * low in node2.
941 		 */
942 		nodehdr2.count += count;
943 		tmp = count * (uint)sizeof(xfs_da_node_entry_t);
944 		btree_s = &btree1[nodehdr1.count - count];
945 		btree_d = &btree2[0];
946 		memcpy(btree_d, btree_s, tmp);
947 		nodehdr1.count -= count;
948 	} else {
949 		/*
950 		 * Move the req'd B-tree elements from low in node2 to
951 		 * high in node1.
952 		 */
953 		count = -count;
954 		tmp = count * (uint)sizeof(xfs_da_node_entry_t);
955 		btree_s = &btree2[0];
956 		btree_d = &btree1[nodehdr1.count];
957 		memcpy(btree_d, btree_s, tmp);
958 		nodehdr1.count += count;
959 
960 		xfs_trans_log_buf(tp, blk1->bp,
961 			XFS_DA_LOGRANGE(node1, btree_d, tmp));
962 
963 		/*
964 		 * Move elements in node2 down to fill the hole.
965 		 */
966 		tmp  = nodehdr2.count - count;
967 		tmp *= (uint)sizeof(xfs_da_node_entry_t);
968 		btree_s = &btree2[count];
969 		btree_d = &btree2[0];
970 		memmove(btree_d, btree_s, tmp);
971 		nodehdr2.count -= count;
972 	}
973 
974 	/*
975 	 * Log header of node 1 and all current bits of node 2.
976 	 */
977 	xfs_da3_node_hdr_to_disk(dp->i_mount, node1, &nodehdr1);
978 	xfs_trans_log_buf(tp, blk1->bp,
979 		XFS_DA_LOGRANGE(node1, &node1->hdr,
980 				state->args->geo->node_hdr_size));
981 
982 	xfs_da3_node_hdr_to_disk(dp->i_mount, node2, &nodehdr2);
983 	xfs_trans_log_buf(tp, blk2->bp,
984 		XFS_DA_LOGRANGE(node2, &node2->hdr,
985 				state->args->geo->node_hdr_size +
986 				(sizeof(btree2[0]) * nodehdr2.count)));
987 
988 	/*
989 	 * Record the last hashval from each block for upward propagation.
990 	 * (note: don't use the swapped node pointers)
991 	 */
992 	if (swap) {
993 		node1 = blk1->bp->b_addr;
994 		node2 = blk2->bp->b_addr;
995 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
996 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
997 		btree1 = nodehdr1.btree;
998 		btree2 = nodehdr2.btree;
999 	}
1000 	blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
1001 	blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
1002 
1003 	/*
1004 	 * Adjust the expected index for insertion.
1005 	 */
1006 	if (blk1->index >= nodehdr1.count) {
1007 		blk2->index = blk1->index - nodehdr1.count;
1008 		blk1->index = nodehdr1.count + 1;	/* make it invalid */
1009 	}
1010 }
1011 
1012 /*
1013  * Add a new entry to an intermediate node.
1014  */
1015 STATIC void
xfs_da3_node_add(struct xfs_da_state * state,struct xfs_da_state_blk * oldblk,struct xfs_da_state_blk * newblk)1016 xfs_da3_node_add(
1017 	struct xfs_da_state	*state,
1018 	struct xfs_da_state_blk	*oldblk,
1019 	struct xfs_da_state_blk	*newblk)
1020 {
1021 	struct xfs_da_intnode	*node;
1022 	struct xfs_da3_icnode_hdr nodehdr;
1023 	struct xfs_da_node_entry *btree;
1024 	int			tmp;
1025 	struct xfs_inode	*dp = state->args->dp;
1026 
1027 	trace_xfs_da_node_add(state->args);
1028 
1029 	node = oldblk->bp->b_addr;
1030 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1031 	btree = nodehdr.btree;
1032 
1033 	ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
1034 	ASSERT(newblk->blkno != 0);
1035 	if (state->args->whichfork == XFS_DATA_FORK)
1036 		ASSERT(newblk->blkno >= state->args->geo->leafblk &&
1037 		       newblk->blkno < state->args->geo->freeblk);
1038 
1039 	/*
1040 	 * We may need to make some room before we insert the new node.
1041 	 */
1042 	tmp = 0;
1043 	if (oldblk->index < nodehdr.count) {
1044 		tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
1045 		memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
1046 	}
1047 	btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
1048 	btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
1049 	xfs_trans_log_buf(state->args->trans, oldblk->bp,
1050 		XFS_DA_LOGRANGE(node, &btree[oldblk->index],
1051 				tmp + sizeof(*btree)));
1052 
1053 	nodehdr.count += 1;
1054 	xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
1055 	xfs_trans_log_buf(state->args->trans, oldblk->bp,
1056 		XFS_DA_LOGRANGE(node, &node->hdr,
1057 				state->args->geo->node_hdr_size));
1058 
1059 	/*
1060 	 * Copy the last hash value from the oldblk to propagate upwards.
1061 	 */
1062 	oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1063 }
1064 
1065 /*========================================================================
1066  * Routines used for shrinking the Btree.
1067  *========================================================================*/
1068 
1069 /*
1070  * Deallocate an empty leaf node, remove it from its parent,
1071  * possibly deallocating that block, etc...
1072  */
1073 int
xfs_da3_join(struct xfs_da_state * state)1074 xfs_da3_join(
1075 	struct xfs_da_state	*state)
1076 {
1077 	struct xfs_da_state_blk	*drop_blk;
1078 	struct xfs_da_state_blk	*save_blk;
1079 	int			action = 0;
1080 	int			error;
1081 
1082 	trace_xfs_da_join(state->args);
1083 
1084 	drop_blk = &state->path.blk[ state->path.active-1 ];
1085 	save_blk = &state->altpath.blk[ state->path.active-1 ];
1086 	ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
1087 	ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
1088 	       drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
1089 
1090 	/*
1091 	 * Walk back up the tree joining/deallocating as necessary.
1092 	 * When we stop dropping blocks, break out.
1093 	 */
1094 	for (  ; state->path.active >= 2; drop_blk--, save_blk--,
1095 		 state->path.active--) {
1096 		/*
1097 		 * See if we can combine the block with a neighbor.
1098 		 *   (action == 0) => no options, just leave
1099 		 *   (action == 1) => coalesce, then unlink
1100 		 *   (action == 2) => block empty, unlink it
1101 		 */
1102 		switch (drop_blk->magic) {
1103 		case XFS_ATTR_LEAF_MAGIC:
1104 			error = xfs_attr3_leaf_toosmall(state, &action);
1105 			if (error)
1106 				return error;
1107 			if (action == 0)
1108 				return 0;
1109 			xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
1110 			break;
1111 		case XFS_DIR2_LEAFN_MAGIC:
1112 			error = xfs_dir2_leafn_toosmall(state, &action);
1113 			if (error)
1114 				return error;
1115 			if (action == 0)
1116 				return 0;
1117 			xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
1118 			break;
1119 		case XFS_DA_NODE_MAGIC:
1120 			/*
1121 			 * Remove the offending node, fixup hashvals,
1122 			 * check for a toosmall neighbor.
1123 			 */
1124 			xfs_da3_node_remove(state, drop_blk);
1125 			xfs_da3_fixhashpath(state, &state->path);
1126 			error = xfs_da3_node_toosmall(state, &action);
1127 			if (error)
1128 				return error;
1129 			if (action == 0)
1130 				return 0;
1131 			xfs_da3_node_unbalance(state, drop_blk, save_blk);
1132 			break;
1133 		}
1134 		xfs_da3_fixhashpath(state, &state->altpath);
1135 		error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
1136 		xfs_da_state_kill_altpath(state);
1137 		if (error)
1138 			return error;
1139 		error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1140 							 drop_blk->bp);
1141 		drop_blk->bp = NULL;
1142 		if (error)
1143 			return error;
1144 	}
1145 	/*
1146 	 * We joined all the way to the top.  If it turns out that
1147 	 * we only have one entry in the root, make the child block
1148 	 * the new root.
1149 	 */
1150 	xfs_da3_node_remove(state, drop_blk);
1151 	xfs_da3_fixhashpath(state, &state->path);
1152 	error = xfs_da3_root_join(state, &state->path.blk[0]);
1153 	return error;
1154 }
1155 
1156 #ifdef	DEBUG
1157 static void
xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo * blkinfo,__u16 level)1158 xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1159 {
1160 	__be16	magic = blkinfo->magic;
1161 
1162 	if (level == 1) {
1163 		ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1164 		       magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1165 		       magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1166 		       magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1167 	} else {
1168 		ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1169 		       magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1170 	}
1171 	ASSERT(!blkinfo->forw);
1172 	ASSERT(!blkinfo->back);
1173 }
1174 #else	/* !DEBUG */
1175 #define	xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1176 #endif	/* !DEBUG */
1177 
1178 /*
1179  * We have only one entry in the root.  Copy the only remaining child of
1180  * the old root to block 0 as the new root node.
1181  */
1182 STATIC int
xfs_da3_root_join(struct xfs_da_state * state,struct xfs_da_state_blk * root_blk)1183 xfs_da3_root_join(
1184 	struct xfs_da_state	*state,
1185 	struct xfs_da_state_blk	*root_blk)
1186 {
1187 	struct xfs_da_intnode	*oldroot;
1188 	struct xfs_da_args	*args;
1189 	xfs_dablk_t		child;
1190 	struct xfs_buf		*bp;
1191 	struct xfs_da3_icnode_hdr oldroothdr;
1192 	int			error;
1193 	struct xfs_inode	*dp = state->args->dp;
1194 
1195 	trace_xfs_da_root_join(state->args);
1196 
1197 	ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1198 
1199 	args = state->args;
1200 	oldroot = root_blk->bp->b_addr;
1201 	xfs_da3_node_hdr_from_disk(dp->i_mount, &oldroothdr, oldroot);
1202 	ASSERT(oldroothdr.forw == 0);
1203 	ASSERT(oldroothdr.back == 0);
1204 
1205 	/*
1206 	 * If the root has more than one child, then don't do anything.
1207 	 */
1208 	if (oldroothdr.count > 1)
1209 		return 0;
1210 
1211 	/*
1212 	 * Read in the (only) child block, then copy those bytes into
1213 	 * the root block's buffer and free the original child block.
1214 	 */
1215 	child = be32_to_cpu(oldroothdr.btree[0].before);
1216 	ASSERT(child != 0);
1217 	error = xfs_da3_node_read(args->trans, dp, child, &bp, args->whichfork);
1218 	if (error)
1219 		return error;
1220 	xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1221 
1222 	/*
1223 	 * This could be copying a leaf back into the root block in the case of
1224 	 * there only being a single leaf block left in the tree. Hence we have
1225 	 * to update the b_ops pointer as well to match the buffer type change
1226 	 * that could occur. For dir3 blocks we also need to update the block
1227 	 * number in the buffer header.
1228 	 */
1229 	memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1230 	root_blk->bp->b_ops = bp->b_ops;
1231 	xfs_trans_buf_copy_type(root_blk->bp, bp);
1232 	if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1233 		struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1234 		da3->blkno = cpu_to_be64(xfs_buf_daddr(root_blk->bp));
1235 	}
1236 	xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1237 			  args->geo->blksize - 1);
1238 	error = xfs_da_shrink_inode(args, child, bp);
1239 	return error;
1240 }
1241 
1242 /*
1243  * Check a node block and its neighbors to see if the block should be
1244  * collapsed into one or the other neighbor.  Always keep the block
1245  * with the smaller block number.
1246  * If the current block is over 50% full, don't try to join it, return 0.
1247  * If the block is empty, fill in the state structure and return 2.
1248  * If it can be collapsed, fill in the state structure and return 1.
1249  * If nothing can be done, return 0.
1250  */
1251 STATIC int
xfs_da3_node_toosmall(struct xfs_da_state * state,int * action)1252 xfs_da3_node_toosmall(
1253 	struct xfs_da_state	*state,
1254 	int			*action)
1255 {
1256 	struct xfs_da_intnode	*node;
1257 	struct xfs_da_state_blk	*blk;
1258 	struct xfs_da_blkinfo	*info;
1259 	xfs_dablk_t		blkno;
1260 	struct xfs_buf		*bp;
1261 	struct xfs_da3_icnode_hdr nodehdr;
1262 	int			count;
1263 	int			forward;
1264 	int			error;
1265 	int			retval;
1266 	int			i;
1267 	struct xfs_inode	*dp = state->args->dp;
1268 
1269 	trace_xfs_da_node_toosmall(state->args);
1270 
1271 	/*
1272 	 * Check for the degenerate case of the block being over 50% full.
1273 	 * If so, it's not worth even looking to see if we might be able
1274 	 * to coalesce with a sibling.
1275 	 */
1276 	blk = &state->path.blk[ state->path.active-1 ];
1277 	info = blk->bp->b_addr;
1278 	node = (xfs_da_intnode_t *)info;
1279 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1280 	if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1281 		*action = 0;	/* blk over 50%, don't try to join */
1282 		return 0;	/* blk over 50%, don't try to join */
1283 	}
1284 
1285 	/*
1286 	 * Check for the degenerate case of the block being empty.
1287 	 * If the block is empty, we'll simply delete it, no need to
1288 	 * coalesce it with a sibling block.  We choose (arbitrarily)
1289 	 * to merge with the forward block unless it is NULL.
1290 	 */
1291 	if (nodehdr.count == 0) {
1292 		/*
1293 		 * Make altpath point to the block we want to keep and
1294 		 * path point to the block we want to drop (this one).
1295 		 */
1296 		forward = (info->forw != 0);
1297 		memcpy(&state->altpath, &state->path, sizeof(state->path));
1298 		error = xfs_da3_path_shift(state, &state->altpath, forward,
1299 						 0, &retval);
1300 		if (error)
1301 			return error;
1302 		if (retval) {
1303 			*action = 0;
1304 		} else {
1305 			*action = 2;
1306 		}
1307 		return 0;
1308 	}
1309 
1310 	/*
1311 	 * Examine each sibling block to see if we can coalesce with
1312 	 * at least 25% free space to spare.  We need to figure out
1313 	 * whether to merge with the forward or the backward block.
1314 	 * We prefer coalescing with the lower numbered sibling so as
1315 	 * to shrink a directory over time.
1316 	 */
1317 	count  = state->args->geo->node_ents;
1318 	count -= state->args->geo->node_ents >> 2;
1319 	count -= nodehdr.count;
1320 
1321 	/* start with smaller blk num */
1322 	forward = nodehdr.forw < nodehdr.back;
1323 	for (i = 0; i < 2; forward = !forward, i++) {
1324 		struct xfs_da3_icnode_hdr thdr;
1325 		if (forward)
1326 			blkno = nodehdr.forw;
1327 		else
1328 			blkno = nodehdr.back;
1329 		if (blkno == 0)
1330 			continue;
1331 		error = xfs_da3_node_read(state->args->trans, dp, blkno, &bp,
1332 				state->args->whichfork);
1333 		if (error)
1334 			return error;
1335 
1336 		node = bp->b_addr;
1337 		xfs_da3_node_hdr_from_disk(dp->i_mount, &thdr, node);
1338 		xfs_trans_brelse(state->args->trans, bp);
1339 
1340 		if (count - thdr.count >= 0)
1341 			break;	/* fits with at least 25% to spare */
1342 	}
1343 	if (i >= 2) {
1344 		*action = 0;
1345 		return 0;
1346 	}
1347 
1348 	/*
1349 	 * Make altpath point to the block we want to keep (the lower
1350 	 * numbered block) and path point to the block we want to drop.
1351 	 */
1352 	memcpy(&state->altpath, &state->path, sizeof(state->path));
1353 	if (blkno < blk->blkno) {
1354 		error = xfs_da3_path_shift(state, &state->altpath, forward,
1355 						 0, &retval);
1356 	} else {
1357 		error = xfs_da3_path_shift(state, &state->path, forward,
1358 						 0, &retval);
1359 	}
1360 	if (error)
1361 		return error;
1362 	if (retval) {
1363 		*action = 0;
1364 		return 0;
1365 	}
1366 	*action = 1;
1367 	return 0;
1368 }
1369 
1370 /*
1371  * Pick up the last hashvalue from an intermediate node.
1372  */
1373 STATIC uint
xfs_da3_node_lasthash(struct xfs_inode * dp,struct xfs_buf * bp,int * count)1374 xfs_da3_node_lasthash(
1375 	struct xfs_inode	*dp,
1376 	struct xfs_buf		*bp,
1377 	int			*count)
1378 {
1379 	struct xfs_da3_icnode_hdr nodehdr;
1380 
1381 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, bp->b_addr);
1382 	if (count)
1383 		*count = nodehdr.count;
1384 	if (!nodehdr.count)
1385 		return 0;
1386 	return be32_to_cpu(nodehdr.btree[nodehdr.count - 1].hashval);
1387 }
1388 
1389 /*
1390  * Walk back up the tree adjusting hash values as necessary,
1391  * when we stop making changes, return.
1392  */
1393 void
xfs_da3_fixhashpath(struct xfs_da_state * state,struct xfs_da_state_path * path)1394 xfs_da3_fixhashpath(
1395 	struct xfs_da_state	*state,
1396 	struct xfs_da_state_path *path)
1397 {
1398 	struct xfs_da_state_blk	*blk;
1399 	struct xfs_da_intnode	*node;
1400 	struct xfs_da_node_entry *btree;
1401 	xfs_dahash_t		lasthash=0;
1402 	int			level;
1403 	int			count;
1404 	struct xfs_inode	*dp = state->args->dp;
1405 
1406 	trace_xfs_da_fixhashpath(state->args);
1407 
1408 	level = path->active-1;
1409 	blk = &path->blk[ level ];
1410 	switch (blk->magic) {
1411 	case XFS_ATTR_LEAF_MAGIC:
1412 		lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1413 		if (count == 0)
1414 			return;
1415 		break;
1416 	case XFS_DIR2_LEAFN_MAGIC:
1417 		lasthash = xfs_dir2_leaf_lasthash(dp, blk->bp, &count);
1418 		if (count == 0)
1419 			return;
1420 		break;
1421 	case XFS_DA_NODE_MAGIC:
1422 		lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1423 		if (count == 0)
1424 			return;
1425 		break;
1426 	}
1427 	for (blk--, level--; level >= 0; blk--, level--) {
1428 		struct xfs_da3_icnode_hdr nodehdr;
1429 
1430 		node = blk->bp->b_addr;
1431 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1432 		btree = nodehdr.btree;
1433 		if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1434 			break;
1435 		blk->hashval = lasthash;
1436 		btree[blk->index].hashval = cpu_to_be32(lasthash);
1437 		xfs_trans_log_buf(state->args->trans, blk->bp,
1438 				  XFS_DA_LOGRANGE(node, &btree[blk->index],
1439 						  sizeof(*btree)));
1440 
1441 		lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1442 	}
1443 }
1444 
1445 /*
1446  * Remove an entry from an intermediate node.
1447  */
1448 STATIC void
xfs_da3_node_remove(struct xfs_da_state * state,struct xfs_da_state_blk * drop_blk)1449 xfs_da3_node_remove(
1450 	struct xfs_da_state	*state,
1451 	struct xfs_da_state_blk	*drop_blk)
1452 {
1453 	struct xfs_da_intnode	*node;
1454 	struct xfs_da3_icnode_hdr nodehdr;
1455 	struct xfs_da_node_entry *btree;
1456 	int			index;
1457 	int			tmp;
1458 	struct xfs_inode	*dp = state->args->dp;
1459 
1460 	trace_xfs_da_node_remove(state->args);
1461 
1462 	node = drop_blk->bp->b_addr;
1463 	xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1464 	ASSERT(drop_blk->index < nodehdr.count);
1465 	ASSERT(drop_blk->index >= 0);
1466 
1467 	/*
1468 	 * Copy over the offending entry, or just zero it out.
1469 	 */
1470 	index = drop_blk->index;
1471 	btree = nodehdr.btree;
1472 	if (index < nodehdr.count - 1) {
1473 		tmp  = nodehdr.count - index - 1;
1474 		tmp *= (uint)sizeof(xfs_da_node_entry_t);
1475 		memmove(&btree[index], &btree[index + 1], tmp);
1476 		xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1477 		    XFS_DA_LOGRANGE(node, &btree[index], tmp));
1478 		index = nodehdr.count - 1;
1479 	}
1480 	memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1481 	xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1482 	    XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1483 	nodehdr.count -= 1;
1484 	xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
1485 	xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1486 	    XFS_DA_LOGRANGE(node, &node->hdr, state->args->geo->node_hdr_size));
1487 
1488 	/*
1489 	 * Copy the last hash value from the block to propagate upwards.
1490 	 */
1491 	drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1492 }
1493 
1494 /*
1495  * Unbalance the elements between two intermediate nodes,
1496  * move all Btree elements from one node into another.
1497  */
1498 STATIC void
xfs_da3_node_unbalance(struct xfs_da_state * state,struct xfs_da_state_blk * drop_blk,struct xfs_da_state_blk * save_blk)1499 xfs_da3_node_unbalance(
1500 	struct xfs_da_state	*state,
1501 	struct xfs_da_state_blk	*drop_blk,
1502 	struct xfs_da_state_blk	*save_blk)
1503 {
1504 	struct xfs_da_intnode	*drop_node;
1505 	struct xfs_da_intnode	*save_node;
1506 	struct xfs_da_node_entry *drop_btree;
1507 	struct xfs_da_node_entry *save_btree;
1508 	struct xfs_da3_icnode_hdr drop_hdr;
1509 	struct xfs_da3_icnode_hdr save_hdr;
1510 	struct xfs_trans	*tp;
1511 	int			sindex;
1512 	int			tmp;
1513 	struct xfs_inode	*dp = state->args->dp;
1514 
1515 	trace_xfs_da_node_unbalance(state->args);
1516 
1517 	drop_node = drop_blk->bp->b_addr;
1518 	save_node = save_blk->bp->b_addr;
1519 	xfs_da3_node_hdr_from_disk(dp->i_mount, &drop_hdr, drop_node);
1520 	xfs_da3_node_hdr_from_disk(dp->i_mount, &save_hdr, save_node);
1521 	drop_btree = drop_hdr.btree;
1522 	save_btree = save_hdr.btree;
1523 	tp = state->args->trans;
1524 
1525 	/*
1526 	 * If the dying block has lower hashvals, then move all the
1527 	 * elements in the remaining block up to make a hole.
1528 	 */
1529 	if ((be32_to_cpu(drop_btree[0].hashval) <
1530 			be32_to_cpu(save_btree[0].hashval)) ||
1531 	    (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1532 			be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1533 		/* XXX: check this - is memmove dst correct? */
1534 		tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1535 		memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1536 
1537 		sindex = 0;
1538 		xfs_trans_log_buf(tp, save_blk->bp,
1539 			XFS_DA_LOGRANGE(save_node, &save_btree[0],
1540 				(save_hdr.count + drop_hdr.count) *
1541 						sizeof(xfs_da_node_entry_t)));
1542 	} else {
1543 		sindex = save_hdr.count;
1544 		xfs_trans_log_buf(tp, save_blk->bp,
1545 			XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1546 				drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1547 	}
1548 
1549 	/*
1550 	 * Move all the B-tree elements from drop_blk to save_blk.
1551 	 */
1552 	tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1553 	memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1554 	save_hdr.count += drop_hdr.count;
1555 
1556 	xfs_da3_node_hdr_to_disk(dp->i_mount, save_node, &save_hdr);
1557 	xfs_trans_log_buf(tp, save_blk->bp,
1558 		XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1559 				state->args->geo->node_hdr_size));
1560 
1561 	/*
1562 	 * Save the last hashval in the remaining block for upward propagation.
1563 	 */
1564 	save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1565 }
1566 
1567 /*========================================================================
1568  * Routines used for finding things in the Btree.
1569  *========================================================================*/
1570 
1571 /*
1572  * Walk down the Btree looking for a particular filename, filling
1573  * in the state structure as we go.
1574  *
1575  * We will set the state structure to point to each of the elements
1576  * in each of the nodes where either the hashval is or should be.
1577  *
1578  * We support duplicate hashval's so for each entry in the current
1579  * node that could contain the desired hashval, descend.  This is a
1580  * pruned depth-first tree search.
1581  */
1582 int							/* error */
xfs_da3_node_lookup_int(struct xfs_da_state * state,int * result)1583 xfs_da3_node_lookup_int(
1584 	struct xfs_da_state	*state,
1585 	int			*result)
1586 {
1587 	struct xfs_da_state_blk	*blk;
1588 	struct xfs_da_blkinfo	*curr;
1589 	struct xfs_da_intnode	*node;
1590 	struct xfs_da_node_entry *btree;
1591 	struct xfs_da3_icnode_hdr nodehdr;
1592 	struct xfs_da_args	*args;
1593 	xfs_dablk_t		blkno;
1594 	xfs_dahash_t		hashval;
1595 	xfs_dahash_t		btreehashval;
1596 	int			probe;
1597 	int			span;
1598 	int			max;
1599 	int			error;
1600 	int			retval;
1601 	unsigned int		expected_level = 0;
1602 	uint16_t		magic;
1603 	struct xfs_inode	*dp = state->args->dp;
1604 
1605 	args = state->args;
1606 
1607 	/*
1608 	 * Descend thru the B-tree searching each level for the right
1609 	 * node to use, until the right hashval is found.
1610 	 */
1611 	blkno = args->geo->leafblk;
1612 	for (blk = &state->path.blk[0], state->path.active = 1;
1613 			 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1614 			 blk++, state->path.active++) {
1615 		/*
1616 		 * Read the next node down in the tree.
1617 		 */
1618 		blk->blkno = blkno;
1619 		error = xfs_da3_node_read(args->trans, args->dp, blkno,
1620 					&blk->bp, args->whichfork);
1621 		if (error) {
1622 			blk->blkno = 0;
1623 			state->path.active--;
1624 			return error;
1625 		}
1626 		curr = blk->bp->b_addr;
1627 		magic = be16_to_cpu(curr->magic);
1628 
1629 		if (magic == XFS_ATTR_LEAF_MAGIC ||
1630 		    magic == XFS_ATTR3_LEAF_MAGIC) {
1631 			blk->magic = XFS_ATTR_LEAF_MAGIC;
1632 			blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1633 			break;
1634 		}
1635 
1636 		if (magic == XFS_DIR2_LEAFN_MAGIC ||
1637 		    magic == XFS_DIR3_LEAFN_MAGIC) {
1638 			blk->magic = XFS_DIR2_LEAFN_MAGIC;
1639 			blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
1640 							      blk->bp, NULL);
1641 			break;
1642 		}
1643 
1644 		if (magic != XFS_DA_NODE_MAGIC && magic != XFS_DA3_NODE_MAGIC) {
1645 			xfs_buf_mark_corrupt(blk->bp);
1646 			return -EFSCORRUPTED;
1647 		}
1648 
1649 		blk->magic = XFS_DA_NODE_MAGIC;
1650 
1651 		/*
1652 		 * Search an intermediate node for a match.
1653 		 */
1654 		node = blk->bp->b_addr;
1655 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1656 		btree = nodehdr.btree;
1657 
1658 		/* Tree taller than we can handle; bail out! */
1659 		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH) {
1660 			xfs_buf_mark_corrupt(blk->bp);
1661 			return -EFSCORRUPTED;
1662 		}
1663 
1664 		/* Check the level from the root. */
1665 		if (blkno == args->geo->leafblk)
1666 			expected_level = nodehdr.level - 1;
1667 		else if (expected_level != nodehdr.level) {
1668 			xfs_buf_mark_corrupt(blk->bp);
1669 			return -EFSCORRUPTED;
1670 		} else
1671 			expected_level--;
1672 
1673 		max = nodehdr.count;
1674 		blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1675 
1676 		/*
1677 		 * Binary search.  (note: small blocks will skip loop)
1678 		 */
1679 		probe = span = max / 2;
1680 		hashval = args->hashval;
1681 		while (span > 4) {
1682 			span /= 2;
1683 			btreehashval = be32_to_cpu(btree[probe].hashval);
1684 			if (btreehashval < hashval)
1685 				probe += span;
1686 			else if (btreehashval > hashval)
1687 				probe -= span;
1688 			else
1689 				break;
1690 		}
1691 		ASSERT((probe >= 0) && (probe < max));
1692 		ASSERT((span <= 4) ||
1693 			(be32_to_cpu(btree[probe].hashval) == hashval));
1694 
1695 		/*
1696 		 * Since we may have duplicate hashval's, find the first
1697 		 * matching hashval in the node.
1698 		 */
1699 		while (probe > 0 &&
1700 		       be32_to_cpu(btree[probe].hashval) >= hashval) {
1701 			probe--;
1702 		}
1703 		while (probe < max &&
1704 		       be32_to_cpu(btree[probe].hashval) < hashval) {
1705 			probe++;
1706 		}
1707 
1708 		/*
1709 		 * Pick the right block to descend on.
1710 		 */
1711 		if (probe == max) {
1712 			blk->index = max - 1;
1713 			blkno = be32_to_cpu(btree[max - 1].before);
1714 		} else {
1715 			blk->index = probe;
1716 			blkno = be32_to_cpu(btree[probe].before);
1717 		}
1718 
1719 		/* We can't point back to the root. */
1720 		if (XFS_IS_CORRUPT(dp->i_mount, blkno == args->geo->leafblk))
1721 			return -EFSCORRUPTED;
1722 	}
1723 
1724 	if (XFS_IS_CORRUPT(dp->i_mount, expected_level != 0))
1725 		return -EFSCORRUPTED;
1726 
1727 	/*
1728 	 * A leaf block that ends in the hashval that we are interested in
1729 	 * (final hashval == search hashval) means that the next block may
1730 	 * contain more entries with the same hashval, shift upward to the
1731 	 * next leaf and keep searching.
1732 	 */
1733 	for (;;) {
1734 		if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1735 			retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1736 							&blk->index, state);
1737 		} else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1738 			retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1739 			blk->index = args->index;
1740 			args->blkno = blk->blkno;
1741 		} else {
1742 			ASSERT(0);
1743 			return -EFSCORRUPTED;
1744 		}
1745 		if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1746 		    (blk->hashval == args->hashval)) {
1747 			error = xfs_da3_path_shift(state, &state->path, 1, 1,
1748 							 &retval);
1749 			if (error)
1750 				return error;
1751 			if (retval == 0) {
1752 				continue;
1753 			} else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1754 				/* path_shift() gives ENOENT */
1755 				retval = -ENOATTR;
1756 			}
1757 		}
1758 		break;
1759 	}
1760 	*result = retval;
1761 	return 0;
1762 }
1763 
1764 /*========================================================================
1765  * Utility routines.
1766  *========================================================================*/
1767 
1768 /*
1769  * Compare two intermediate nodes for "order".
1770  */
1771 STATIC int
xfs_da3_node_order(struct xfs_inode * dp,struct xfs_buf * node1_bp,struct xfs_buf * node2_bp)1772 xfs_da3_node_order(
1773 	struct xfs_inode *dp,
1774 	struct xfs_buf	*node1_bp,
1775 	struct xfs_buf	*node2_bp)
1776 {
1777 	struct xfs_da_intnode	*node1;
1778 	struct xfs_da_intnode	*node2;
1779 	struct xfs_da_node_entry *btree1;
1780 	struct xfs_da_node_entry *btree2;
1781 	struct xfs_da3_icnode_hdr node1hdr;
1782 	struct xfs_da3_icnode_hdr node2hdr;
1783 
1784 	node1 = node1_bp->b_addr;
1785 	node2 = node2_bp->b_addr;
1786 	xfs_da3_node_hdr_from_disk(dp->i_mount, &node1hdr, node1);
1787 	xfs_da3_node_hdr_from_disk(dp->i_mount, &node2hdr, node2);
1788 	btree1 = node1hdr.btree;
1789 	btree2 = node2hdr.btree;
1790 
1791 	if (node1hdr.count > 0 && node2hdr.count > 0 &&
1792 	    ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1793 	     (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1794 	      be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1795 		return 1;
1796 	}
1797 	return 0;
1798 }
1799 
1800 /*
1801  * Link a new block into a doubly linked list of blocks (of whatever type).
1802  */
1803 int							/* error */
xfs_da3_blk_link(struct xfs_da_state * state,struct xfs_da_state_blk * old_blk,struct xfs_da_state_blk * new_blk)1804 xfs_da3_blk_link(
1805 	struct xfs_da_state	*state,
1806 	struct xfs_da_state_blk	*old_blk,
1807 	struct xfs_da_state_blk	*new_blk)
1808 {
1809 	struct xfs_da_blkinfo	*old_info;
1810 	struct xfs_da_blkinfo	*new_info;
1811 	struct xfs_da_blkinfo	*tmp_info;
1812 	struct xfs_da_args	*args;
1813 	struct xfs_buf		*bp;
1814 	int			before = 0;
1815 	int			error;
1816 	struct xfs_inode	*dp = state->args->dp;
1817 
1818 	/*
1819 	 * Set up environment.
1820 	 */
1821 	args = state->args;
1822 	ASSERT(args != NULL);
1823 	old_info = old_blk->bp->b_addr;
1824 	new_info = new_blk->bp->b_addr;
1825 	ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1826 	       old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1827 	       old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1828 
1829 	switch (old_blk->magic) {
1830 	case XFS_ATTR_LEAF_MAGIC:
1831 		before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1832 		break;
1833 	case XFS_DIR2_LEAFN_MAGIC:
1834 		before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1835 		break;
1836 	case XFS_DA_NODE_MAGIC:
1837 		before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1838 		break;
1839 	}
1840 
1841 	/*
1842 	 * Link blocks in appropriate order.
1843 	 */
1844 	if (before) {
1845 		/*
1846 		 * Link new block in before existing block.
1847 		 */
1848 		trace_xfs_da_link_before(args);
1849 		new_info->forw = cpu_to_be32(old_blk->blkno);
1850 		new_info->back = old_info->back;
1851 		if (old_info->back) {
1852 			error = xfs_da3_node_read(args->trans, dp,
1853 						be32_to_cpu(old_info->back),
1854 						&bp, args->whichfork);
1855 			if (error)
1856 				return error;
1857 			ASSERT(bp != NULL);
1858 			tmp_info = bp->b_addr;
1859 			ASSERT(tmp_info->magic == old_info->magic);
1860 			ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1861 			tmp_info->forw = cpu_to_be32(new_blk->blkno);
1862 			xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1863 		}
1864 		old_info->back = cpu_to_be32(new_blk->blkno);
1865 	} else {
1866 		/*
1867 		 * Link new block in after existing block.
1868 		 */
1869 		trace_xfs_da_link_after(args);
1870 		new_info->forw = old_info->forw;
1871 		new_info->back = cpu_to_be32(old_blk->blkno);
1872 		if (old_info->forw) {
1873 			error = xfs_da3_node_read(args->trans, dp,
1874 						be32_to_cpu(old_info->forw),
1875 						&bp, args->whichfork);
1876 			if (error)
1877 				return error;
1878 			ASSERT(bp != NULL);
1879 			tmp_info = bp->b_addr;
1880 			ASSERT(tmp_info->magic == old_info->magic);
1881 			ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1882 			tmp_info->back = cpu_to_be32(new_blk->blkno);
1883 			xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1884 		}
1885 		old_info->forw = cpu_to_be32(new_blk->blkno);
1886 	}
1887 
1888 	xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1889 	xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1890 	return 0;
1891 }
1892 
1893 /*
1894  * Unlink a block from a doubly linked list of blocks.
1895  */
1896 STATIC int						/* error */
xfs_da3_blk_unlink(struct xfs_da_state * state,struct xfs_da_state_blk * drop_blk,struct xfs_da_state_blk * save_blk)1897 xfs_da3_blk_unlink(
1898 	struct xfs_da_state	*state,
1899 	struct xfs_da_state_blk	*drop_blk,
1900 	struct xfs_da_state_blk	*save_blk)
1901 {
1902 	struct xfs_da_blkinfo	*drop_info;
1903 	struct xfs_da_blkinfo	*save_info;
1904 	struct xfs_da_blkinfo	*tmp_info;
1905 	struct xfs_da_args	*args;
1906 	struct xfs_buf		*bp;
1907 	int			error;
1908 
1909 	/*
1910 	 * Set up environment.
1911 	 */
1912 	args = state->args;
1913 	ASSERT(args != NULL);
1914 	save_info = save_blk->bp->b_addr;
1915 	drop_info = drop_blk->bp->b_addr;
1916 	ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1917 	       save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1918 	       save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1919 	ASSERT(save_blk->magic == drop_blk->magic);
1920 	ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1921 	       (be32_to_cpu(save_info->back) == drop_blk->blkno));
1922 	ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1923 	       (be32_to_cpu(drop_info->back) == save_blk->blkno));
1924 
1925 	/*
1926 	 * Unlink the leaf block from the doubly linked chain of leaves.
1927 	 */
1928 	if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1929 		trace_xfs_da_unlink_back(args);
1930 		save_info->back = drop_info->back;
1931 		if (drop_info->back) {
1932 			error = xfs_da3_node_read(args->trans, args->dp,
1933 						be32_to_cpu(drop_info->back),
1934 						&bp, args->whichfork);
1935 			if (error)
1936 				return error;
1937 			ASSERT(bp != NULL);
1938 			tmp_info = bp->b_addr;
1939 			ASSERT(tmp_info->magic == save_info->magic);
1940 			ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1941 			tmp_info->forw = cpu_to_be32(save_blk->blkno);
1942 			xfs_trans_log_buf(args->trans, bp, 0,
1943 						    sizeof(*tmp_info) - 1);
1944 		}
1945 	} else {
1946 		trace_xfs_da_unlink_forward(args);
1947 		save_info->forw = drop_info->forw;
1948 		if (drop_info->forw) {
1949 			error = xfs_da3_node_read(args->trans, args->dp,
1950 						be32_to_cpu(drop_info->forw),
1951 						&bp, args->whichfork);
1952 			if (error)
1953 				return error;
1954 			ASSERT(bp != NULL);
1955 			tmp_info = bp->b_addr;
1956 			ASSERT(tmp_info->magic == save_info->magic);
1957 			ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1958 			tmp_info->back = cpu_to_be32(save_blk->blkno);
1959 			xfs_trans_log_buf(args->trans, bp, 0,
1960 						    sizeof(*tmp_info) - 1);
1961 		}
1962 	}
1963 
1964 	xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1965 	return 0;
1966 }
1967 
1968 /*
1969  * Move a path "forward" or "!forward" one block at the current level.
1970  *
1971  * This routine will adjust a "path" to point to the next block
1972  * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1973  * Btree, including updating pointers to the intermediate nodes between
1974  * the new bottom and the root.
1975  */
1976 int							/* error */
xfs_da3_path_shift(struct xfs_da_state * state,struct xfs_da_state_path * path,int forward,int release,int * result)1977 xfs_da3_path_shift(
1978 	struct xfs_da_state	*state,
1979 	struct xfs_da_state_path *path,
1980 	int			forward,
1981 	int			release,
1982 	int			*result)
1983 {
1984 	struct xfs_da_state_blk	*blk;
1985 	struct xfs_da_blkinfo	*info;
1986 	struct xfs_da_args	*args;
1987 	struct xfs_da_node_entry *btree;
1988 	struct xfs_da3_icnode_hdr nodehdr;
1989 	struct xfs_buf		*bp;
1990 	xfs_dablk_t		blkno = 0;
1991 	int			level;
1992 	int			error;
1993 	struct xfs_inode	*dp = state->args->dp;
1994 
1995 	trace_xfs_da_path_shift(state->args);
1996 
1997 	/*
1998 	 * Roll up the Btree looking for the first block where our
1999 	 * current index is not at the edge of the block.  Note that
2000 	 * we skip the bottom layer because we want the sibling block.
2001 	 */
2002 	args = state->args;
2003 	ASSERT(args != NULL);
2004 	ASSERT(path != NULL);
2005 	ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
2006 	level = (path->active-1) - 1;	/* skip bottom layer in path */
2007 	for (; level >= 0; level--) {
2008 		blk = &path->blk[level];
2009 		xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr,
2010 					   blk->bp->b_addr);
2011 
2012 		if (forward && (blk->index < nodehdr.count - 1)) {
2013 			blk->index++;
2014 			blkno = be32_to_cpu(nodehdr.btree[blk->index].before);
2015 			break;
2016 		} else if (!forward && (blk->index > 0)) {
2017 			blk->index--;
2018 			blkno = be32_to_cpu(nodehdr.btree[blk->index].before);
2019 			break;
2020 		}
2021 	}
2022 	if (level < 0) {
2023 		*result = -ENOENT;	/* we're out of our tree */
2024 		ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
2025 		return 0;
2026 	}
2027 
2028 	/*
2029 	 * Roll down the edge of the subtree until we reach the
2030 	 * same depth we were at originally.
2031 	 */
2032 	for (blk++, level++; level < path->active; blk++, level++) {
2033 		/*
2034 		 * Read the next child block into a local buffer.
2035 		 */
2036 		error = xfs_da3_node_read(args->trans, dp, blkno, &bp,
2037 					  args->whichfork);
2038 		if (error)
2039 			return error;
2040 
2041 		/*
2042 		 * Release the old block (if it's dirty, the trans doesn't
2043 		 * actually let go) and swap the local buffer into the path
2044 		 * structure. This ensures failure of the above read doesn't set
2045 		 * a NULL buffer in an active slot in the path.
2046 		 */
2047 		if (release)
2048 			xfs_trans_brelse(args->trans, blk->bp);
2049 		blk->blkno = blkno;
2050 		blk->bp = bp;
2051 
2052 		info = blk->bp->b_addr;
2053 		ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
2054 		       info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
2055 		       info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2056 		       info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
2057 		       info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
2058 		       info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
2059 
2060 
2061 		/*
2062 		 * Note: we flatten the magic number to a single type so we
2063 		 * don't have to compare against crc/non-crc types elsewhere.
2064 		 */
2065 		switch (be16_to_cpu(info->magic)) {
2066 		case XFS_DA_NODE_MAGIC:
2067 		case XFS_DA3_NODE_MAGIC:
2068 			blk->magic = XFS_DA_NODE_MAGIC;
2069 			xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr,
2070 						   bp->b_addr);
2071 			btree = nodehdr.btree;
2072 			blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
2073 			if (forward)
2074 				blk->index = 0;
2075 			else
2076 				blk->index = nodehdr.count - 1;
2077 			blkno = be32_to_cpu(btree[blk->index].before);
2078 			break;
2079 		case XFS_ATTR_LEAF_MAGIC:
2080 		case XFS_ATTR3_LEAF_MAGIC:
2081 			blk->magic = XFS_ATTR_LEAF_MAGIC;
2082 			ASSERT(level == path->active-1);
2083 			blk->index = 0;
2084 			blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
2085 			break;
2086 		case XFS_DIR2_LEAFN_MAGIC:
2087 		case XFS_DIR3_LEAFN_MAGIC:
2088 			blk->magic = XFS_DIR2_LEAFN_MAGIC;
2089 			ASSERT(level == path->active-1);
2090 			blk->index = 0;
2091 			blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
2092 							      blk->bp, NULL);
2093 			break;
2094 		default:
2095 			ASSERT(0);
2096 			break;
2097 		}
2098 	}
2099 	*result = 0;
2100 	return 0;
2101 }
2102 
2103 
2104 /*========================================================================
2105  * Utility routines.
2106  *========================================================================*/
2107 
2108 /*
2109  * Implement a simple hash on a character string.
2110  * Rotate the hash value by 7 bits, then XOR each character in.
2111  * This is implemented with some source-level loop unrolling.
2112  */
2113 xfs_dahash_t
xfs_da_hashname(const uint8_t * name,int namelen)2114 xfs_da_hashname(const uint8_t *name, int namelen)
2115 {
2116 	xfs_dahash_t hash;
2117 
2118 	/*
2119 	 * Do four characters at a time as long as we can.
2120 	 */
2121 	for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
2122 		hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
2123 		       (name[3] << 0) ^ rol32(hash, 7 * 4);
2124 
2125 	/*
2126 	 * Now do the rest of the characters.
2127 	 */
2128 	switch (namelen) {
2129 	case 3:
2130 		return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
2131 		       rol32(hash, 7 * 3);
2132 	case 2:
2133 		return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
2134 	case 1:
2135 		return (name[0] << 0) ^ rol32(hash, 7 * 1);
2136 	default: /* case 0: */
2137 		return hash;
2138 	}
2139 }
2140 
2141 enum xfs_dacmp
xfs_da_compname(struct xfs_da_args * args,const unsigned char * name,int len)2142 xfs_da_compname(
2143 	struct xfs_da_args *args,
2144 	const unsigned char *name,
2145 	int		len)
2146 {
2147 	return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
2148 					XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
2149 }
2150 
2151 int
xfs_da_grow_inode_int(struct xfs_da_args * args,xfs_fileoff_t * bno,int count)2152 xfs_da_grow_inode_int(
2153 	struct xfs_da_args	*args,
2154 	xfs_fileoff_t		*bno,
2155 	int			count)
2156 {
2157 	struct xfs_trans	*tp = args->trans;
2158 	struct xfs_inode	*dp = args->dp;
2159 	int			w = args->whichfork;
2160 	xfs_rfsblock_t		nblks = dp->i_nblocks;
2161 	struct xfs_bmbt_irec	map, *mapp;
2162 	int			nmap, error, got, i, mapi;
2163 
2164 	/*
2165 	 * Find a spot in the file space to put the new block.
2166 	 */
2167 	error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2168 	if (error)
2169 		return error;
2170 
2171 	/*
2172 	 * Try mapping it in one filesystem block.
2173 	 */
2174 	nmap = 1;
2175 	error = xfs_bmapi_write(tp, dp, *bno, count,
2176 			xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2177 			args->total, &map, &nmap);
2178 	if (error)
2179 		return error;
2180 
2181 	ASSERT(nmap <= 1);
2182 	if (nmap == 1) {
2183 		mapp = &map;
2184 		mapi = 1;
2185 	} else if (nmap == 0 && count > 1) {
2186 		xfs_fileoff_t		b;
2187 		int			c;
2188 
2189 		/*
2190 		 * If we didn't get it and the block might work if fragmented,
2191 		 * try without the CONTIG flag.  Loop until we get it all.
2192 		 */
2193 		mapp = kmem_alloc(sizeof(*mapp) * count, 0);
2194 		for (b = *bno, mapi = 0; b < *bno + count; ) {
2195 			nmap = min(XFS_BMAP_MAX_NMAP, count);
2196 			c = (int)(*bno + count - b);
2197 			error = xfs_bmapi_write(tp, dp, b, c,
2198 					xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2199 					args->total, &mapp[mapi], &nmap);
2200 			if (error)
2201 				goto out_free_map;
2202 			if (nmap < 1)
2203 				break;
2204 			mapi += nmap;
2205 			b = mapp[mapi - 1].br_startoff +
2206 			    mapp[mapi - 1].br_blockcount;
2207 		}
2208 	} else {
2209 		mapi = 0;
2210 		mapp = NULL;
2211 	}
2212 
2213 	/*
2214 	 * Count the blocks we got, make sure it matches the total.
2215 	 */
2216 	for (i = 0, got = 0; i < mapi; i++)
2217 		got += mapp[i].br_blockcount;
2218 	if (got != count || mapp[0].br_startoff != *bno ||
2219 	    mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2220 	    *bno + count) {
2221 		error = -ENOSPC;
2222 		goto out_free_map;
2223 	}
2224 
2225 	/* account for newly allocated blocks in reserved blocks total */
2226 	args->total -= dp->i_nblocks - nblks;
2227 
2228 out_free_map:
2229 	if (mapp != &map)
2230 		kmem_free(mapp);
2231 	return error;
2232 }
2233 
2234 /*
2235  * Add a block to the btree ahead of the file.
2236  * Return the new block number to the caller.
2237  */
2238 int
xfs_da_grow_inode(struct xfs_da_args * args,xfs_dablk_t * new_blkno)2239 xfs_da_grow_inode(
2240 	struct xfs_da_args	*args,
2241 	xfs_dablk_t		*new_blkno)
2242 {
2243 	xfs_fileoff_t		bno;
2244 	int			error;
2245 
2246 	trace_xfs_da_grow_inode(args);
2247 
2248 	bno = args->geo->leafblk;
2249 	error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2250 	if (!error)
2251 		*new_blkno = (xfs_dablk_t)bno;
2252 	return error;
2253 }
2254 
2255 /*
2256  * Ick.  We need to always be able to remove a btree block, even
2257  * if there's no space reservation because the filesystem is full.
2258  * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2259  * It swaps the target block with the last block in the file.  The
2260  * last block in the file can always be removed since it can't cause
2261  * a bmap btree split to do that.
2262  */
2263 STATIC int
xfs_da3_swap_lastblock(struct xfs_da_args * args,xfs_dablk_t * dead_blknop,struct xfs_buf ** dead_bufp)2264 xfs_da3_swap_lastblock(
2265 	struct xfs_da_args	*args,
2266 	xfs_dablk_t		*dead_blknop,
2267 	struct xfs_buf		**dead_bufp)
2268 {
2269 	struct xfs_da_blkinfo	*dead_info;
2270 	struct xfs_da_blkinfo	*sib_info;
2271 	struct xfs_da_intnode	*par_node;
2272 	struct xfs_da_intnode	*dead_node;
2273 	struct xfs_dir2_leaf	*dead_leaf2;
2274 	struct xfs_da_node_entry *btree;
2275 	struct xfs_da3_icnode_hdr par_hdr;
2276 	struct xfs_inode	*dp;
2277 	struct xfs_trans	*tp;
2278 	struct xfs_mount	*mp;
2279 	struct xfs_buf		*dead_buf;
2280 	struct xfs_buf		*last_buf;
2281 	struct xfs_buf		*sib_buf;
2282 	struct xfs_buf		*par_buf;
2283 	xfs_dahash_t		dead_hash;
2284 	xfs_fileoff_t		lastoff;
2285 	xfs_dablk_t		dead_blkno;
2286 	xfs_dablk_t		last_blkno;
2287 	xfs_dablk_t		sib_blkno;
2288 	xfs_dablk_t		par_blkno;
2289 	int			error;
2290 	int			w;
2291 	int			entno;
2292 	int			level;
2293 	int			dead_level;
2294 
2295 	trace_xfs_da_swap_lastblock(args);
2296 
2297 	dead_buf = *dead_bufp;
2298 	dead_blkno = *dead_blknop;
2299 	tp = args->trans;
2300 	dp = args->dp;
2301 	w = args->whichfork;
2302 	ASSERT(w == XFS_DATA_FORK);
2303 	mp = dp->i_mount;
2304 	lastoff = args->geo->freeblk;
2305 	error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2306 	if (error)
2307 		return error;
2308 	if (XFS_IS_CORRUPT(mp, lastoff == 0))
2309 		return -EFSCORRUPTED;
2310 	/*
2311 	 * Read the last block in the btree space.
2312 	 */
2313 	last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2314 	error = xfs_da3_node_read(tp, dp, last_blkno, &last_buf, w);
2315 	if (error)
2316 		return error;
2317 	/*
2318 	 * Copy the last block into the dead buffer and log it.
2319 	 */
2320 	memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2321 	xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2322 	dead_info = dead_buf->b_addr;
2323 	/*
2324 	 * Get values from the moved block.
2325 	 */
2326 	if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2327 	    dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2328 		struct xfs_dir3_icleaf_hdr leafhdr;
2329 		struct xfs_dir2_leaf_entry *ents;
2330 
2331 		dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2332 		xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr,
2333 					    dead_leaf2);
2334 		ents = leafhdr.ents;
2335 		dead_level = 0;
2336 		dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2337 	} else {
2338 		struct xfs_da3_icnode_hdr deadhdr;
2339 
2340 		dead_node = (xfs_da_intnode_t *)dead_info;
2341 		xfs_da3_node_hdr_from_disk(dp->i_mount, &deadhdr, dead_node);
2342 		btree = deadhdr.btree;
2343 		dead_level = deadhdr.level;
2344 		dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2345 	}
2346 	sib_buf = par_buf = NULL;
2347 	/*
2348 	 * If the moved block has a left sibling, fix up the pointers.
2349 	 */
2350 	if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2351 		error = xfs_da3_node_read(tp, dp, sib_blkno, &sib_buf, w);
2352 		if (error)
2353 			goto done;
2354 		sib_info = sib_buf->b_addr;
2355 		if (XFS_IS_CORRUPT(mp,
2356 				   be32_to_cpu(sib_info->forw) != last_blkno ||
2357 				   sib_info->magic != dead_info->magic)) {
2358 			error = -EFSCORRUPTED;
2359 			goto done;
2360 		}
2361 		sib_info->forw = cpu_to_be32(dead_blkno);
2362 		xfs_trans_log_buf(tp, sib_buf,
2363 			XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2364 					sizeof(sib_info->forw)));
2365 		sib_buf = NULL;
2366 	}
2367 	/*
2368 	 * If the moved block has a right sibling, fix up the pointers.
2369 	 */
2370 	if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2371 		error = xfs_da3_node_read(tp, dp, sib_blkno, &sib_buf, w);
2372 		if (error)
2373 			goto done;
2374 		sib_info = sib_buf->b_addr;
2375 		if (XFS_IS_CORRUPT(mp,
2376 				   be32_to_cpu(sib_info->back) != last_blkno ||
2377 				   sib_info->magic != dead_info->magic)) {
2378 			error = -EFSCORRUPTED;
2379 			goto done;
2380 		}
2381 		sib_info->back = cpu_to_be32(dead_blkno);
2382 		xfs_trans_log_buf(tp, sib_buf,
2383 			XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2384 					sizeof(sib_info->back)));
2385 		sib_buf = NULL;
2386 	}
2387 	par_blkno = args->geo->leafblk;
2388 	level = -1;
2389 	/*
2390 	 * Walk down the tree looking for the parent of the moved block.
2391 	 */
2392 	for (;;) {
2393 		error = xfs_da3_node_read(tp, dp, par_blkno, &par_buf, w);
2394 		if (error)
2395 			goto done;
2396 		par_node = par_buf->b_addr;
2397 		xfs_da3_node_hdr_from_disk(dp->i_mount, &par_hdr, par_node);
2398 		if (XFS_IS_CORRUPT(mp,
2399 				   level >= 0 && level != par_hdr.level + 1)) {
2400 			error = -EFSCORRUPTED;
2401 			goto done;
2402 		}
2403 		level = par_hdr.level;
2404 		btree = par_hdr.btree;
2405 		for (entno = 0;
2406 		     entno < par_hdr.count &&
2407 		     be32_to_cpu(btree[entno].hashval) < dead_hash;
2408 		     entno++)
2409 			continue;
2410 		if (XFS_IS_CORRUPT(mp, entno == par_hdr.count)) {
2411 			error = -EFSCORRUPTED;
2412 			goto done;
2413 		}
2414 		par_blkno = be32_to_cpu(btree[entno].before);
2415 		if (level == dead_level + 1)
2416 			break;
2417 		xfs_trans_brelse(tp, par_buf);
2418 		par_buf = NULL;
2419 	}
2420 	/*
2421 	 * We're in the right parent block.
2422 	 * Look for the right entry.
2423 	 */
2424 	for (;;) {
2425 		for (;
2426 		     entno < par_hdr.count &&
2427 		     be32_to_cpu(btree[entno].before) != last_blkno;
2428 		     entno++)
2429 			continue;
2430 		if (entno < par_hdr.count)
2431 			break;
2432 		par_blkno = par_hdr.forw;
2433 		xfs_trans_brelse(tp, par_buf);
2434 		par_buf = NULL;
2435 		if (XFS_IS_CORRUPT(mp, par_blkno == 0)) {
2436 			error = -EFSCORRUPTED;
2437 			goto done;
2438 		}
2439 		error = xfs_da3_node_read(tp, dp, par_blkno, &par_buf, w);
2440 		if (error)
2441 			goto done;
2442 		par_node = par_buf->b_addr;
2443 		xfs_da3_node_hdr_from_disk(dp->i_mount, &par_hdr, par_node);
2444 		if (XFS_IS_CORRUPT(mp, par_hdr.level != level)) {
2445 			error = -EFSCORRUPTED;
2446 			goto done;
2447 		}
2448 		btree = par_hdr.btree;
2449 		entno = 0;
2450 	}
2451 	/*
2452 	 * Update the parent entry pointing to the moved block.
2453 	 */
2454 	btree[entno].before = cpu_to_be32(dead_blkno);
2455 	xfs_trans_log_buf(tp, par_buf,
2456 		XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2457 				sizeof(btree[entno].before)));
2458 	*dead_blknop = last_blkno;
2459 	*dead_bufp = last_buf;
2460 	return 0;
2461 done:
2462 	if (par_buf)
2463 		xfs_trans_brelse(tp, par_buf);
2464 	if (sib_buf)
2465 		xfs_trans_brelse(tp, sib_buf);
2466 	xfs_trans_brelse(tp, last_buf);
2467 	return error;
2468 }
2469 
2470 /*
2471  * Remove a btree block from a directory or attribute.
2472  */
2473 int
xfs_da_shrink_inode(struct xfs_da_args * args,xfs_dablk_t dead_blkno,struct xfs_buf * dead_buf)2474 xfs_da_shrink_inode(
2475 	struct xfs_da_args	*args,
2476 	xfs_dablk_t		dead_blkno,
2477 	struct xfs_buf		*dead_buf)
2478 {
2479 	struct xfs_inode	*dp;
2480 	int			done, error, w, count;
2481 	struct xfs_trans	*tp;
2482 
2483 	trace_xfs_da_shrink_inode(args);
2484 
2485 	dp = args->dp;
2486 	w = args->whichfork;
2487 	tp = args->trans;
2488 	count = args->geo->fsbcount;
2489 	for (;;) {
2490 		/*
2491 		 * Remove extents.  If we get ENOSPC for a dir we have to move
2492 		 * the last block to the place we want to kill.
2493 		 */
2494 		error = xfs_bunmapi(tp, dp, dead_blkno, count,
2495 				    xfs_bmapi_aflag(w), 0, &done);
2496 		if (error == -ENOSPC) {
2497 			if (w != XFS_DATA_FORK)
2498 				break;
2499 			error = xfs_da3_swap_lastblock(args, &dead_blkno,
2500 						      &dead_buf);
2501 			if (error)
2502 				break;
2503 		} else {
2504 			break;
2505 		}
2506 	}
2507 	xfs_trans_binval(tp, dead_buf);
2508 	return error;
2509 }
2510 
2511 static int
xfs_dabuf_map(struct xfs_inode * dp,xfs_dablk_t bno,unsigned int flags,int whichfork,struct xfs_buf_map ** mapp,int * nmaps)2512 xfs_dabuf_map(
2513 	struct xfs_inode	*dp,
2514 	xfs_dablk_t		bno,
2515 	unsigned int		flags,
2516 	int			whichfork,
2517 	struct xfs_buf_map	**mapp,
2518 	int			*nmaps)
2519 {
2520 	struct xfs_mount	*mp = dp->i_mount;
2521 	int			nfsb = xfs_dabuf_nfsb(mp, whichfork);
2522 	struct xfs_bmbt_irec	irec, *irecs = &irec;
2523 	struct xfs_buf_map	*map = *mapp;
2524 	xfs_fileoff_t		off = bno;
2525 	int			error = 0, nirecs, i;
2526 
2527 	if (nfsb > 1)
2528 		irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_NOFS);
2529 
2530 	nirecs = nfsb;
2531 	error = xfs_bmapi_read(dp, bno, nfsb, irecs, &nirecs,
2532 			xfs_bmapi_aflag(whichfork));
2533 	if (error)
2534 		goto out_free_irecs;
2535 
2536 	/*
2537 	 * Use the caller provided map for the single map case, else allocate a
2538 	 * larger one that needs to be free by the caller.
2539 	 */
2540 	if (nirecs > 1) {
2541 		map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_NOFS);
2542 		if (!map) {
2543 			error = -ENOMEM;
2544 			goto out_free_irecs;
2545 		}
2546 		*mapp = map;
2547 	}
2548 
2549 	for (i = 0; i < nirecs; i++) {
2550 		if (irecs[i].br_startblock == HOLESTARTBLOCK ||
2551 		    irecs[i].br_startblock == DELAYSTARTBLOCK)
2552 			goto invalid_mapping;
2553 		if (off != irecs[i].br_startoff)
2554 			goto invalid_mapping;
2555 
2556 		map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2557 		map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2558 		off += irecs[i].br_blockcount;
2559 	}
2560 
2561 	if (off != bno + nfsb)
2562 		goto invalid_mapping;
2563 
2564 	*nmaps = nirecs;
2565 out_free_irecs:
2566 	if (irecs != &irec)
2567 		kmem_free(irecs);
2568 	return error;
2569 
2570 invalid_mapping:
2571 	/* Caller ok with no mapping. */
2572 	if (XFS_IS_CORRUPT(mp, !(flags & XFS_DABUF_MAP_HOLE_OK))) {
2573 		error = -EFSCORRUPTED;
2574 		if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2575 			xfs_alert(mp, "%s: bno %u inode %llu",
2576 					__func__, bno, dp->i_ino);
2577 
2578 			for (i = 0; i < nirecs; i++) {
2579 				xfs_alert(mp,
2580 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2581 					i, irecs[i].br_startoff,
2582 					irecs[i].br_startblock,
2583 					irecs[i].br_blockcount,
2584 					irecs[i].br_state);
2585 			}
2586 		}
2587 	} else {
2588 		*nmaps = 0;
2589 	}
2590 	goto out_free_irecs;
2591 }
2592 
2593 /*
2594  * Get a buffer for the dir/attr block.
2595  */
2596 int
xfs_da_get_buf(struct xfs_trans * tp,struct xfs_inode * dp,xfs_dablk_t bno,struct xfs_buf ** bpp,int whichfork)2597 xfs_da_get_buf(
2598 	struct xfs_trans	*tp,
2599 	struct xfs_inode	*dp,
2600 	xfs_dablk_t		bno,
2601 	struct xfs_buf		**bpp,
2602 	int			whichfork)
2603 {
2604 	struct xfs_mount	*mp = dp->i_mount;
2605 	struct xfs_buf		*bp;
2606 	struct xfs_buf_map	map, *mapp = &map;
2607 	int			nmap = 1;
2608 	int			error;
2609 
2610 	*bpp = NULL;
2611 	error = xfs_dabuf_map(dp, bno, 0, whichfork, &mapp, &nmap);
2612 	if (error || nmap == 0)
2613 		goto out_free;
2614 
2615 	error = xfs_trans_get_buf_map(tp, mp->m_ddev_targp, mapp, nmap, 0, &bp);
2616 	if (error)
2617 		goto out_free;
2618 
2619 	*bpp = bp;
2620 
2621 out_free:
2622 	if (mapp != &map)
2623 		kmem_free(mapp);
2624 
2625 	return error;
2626 }
2627 
2628 /*
2629  * Get a buffer for the dir/attr block, fill in the contents.
2630  */
2631 int
xfs_da_read_buf(struct xfs_trans * tp,struct xfs_inode * dp,xfs_dablk_t bno,unsigned int flags,struct xfs_buf ** bpp,int whichfork,const struct xfs_buf_ops * ops)2632 xfs_da_read_buf(
2633 	struct xfs_trans	*tp,
2634 	struct xfs_inode	*dp,
2635 	xfs_dablk_t		bno,
2636 	unsigned int		flags,
2637 	struct xfs_buf		**bpp,
2638 	int			whichfork,
2639 	const struct xfs_buf_ops *ops)
2640 {
2641 	struct xfs_mount	*mp = dp->i_mount;
2642 	struct xfs_buf		*bp;
2643 	struct xfs_buf_map	map, *mapp = &map;
2644 	int			nmap = 1;
2645 	int			error;
2646 
2647 	*bpp = NULL;
2648 	error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap);
2649 	if (error || !nmap)
2650 		goto out_free;
2651 
2652 	error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0,
2653 			&bp, ops);
2654 	if (error)
2655 		goto out_free;
2656 
2657 	if (whichfork == XFS_ATTR_FORK)
2658 		xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2659 	else
2660 		xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2661 	*bpp = bp;
2662 out_free:
2663 	if (mapp != &map)
2664 		kmem_free(mapp);
2665 
2666 	return error;
2667 }
2668 
2669 /*
2670  * Readahead the dir/attr block.
2671  */
2672 int
xfs_da_reada_buf(struct xfs_inode * dp,xfs_dablk_t bno,unsigned int flags,int whichfork,const struct xfs_buf_ops * ops)2673 xfs_da_reada_buf(
2674 	struct xfs_inode	*dp,
2675 	xfs_dablk_t		bno,
2676 	unsigned int		flags,
2677 	int			whichfork,
2678 	const struct xfs_buf_ops *ops)
2679 {
2680 	struct xfs_buf_map	map;
2681 	struct xfs_buf_map	*mapp;
2682 	int			nmap;
2683 	int			error;
2684 
2685 	mapp = &map;
2686 	nmap = 1;
2687 	error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap);
2688 	if (error || !nmap)
2689 		goto out_free;
2690 
2691 	xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2692 
2693 out_free:
2694 	if (mapp != &map)
2695 		kmem_free(mapp);
2696 
2697 	return error;
2698 }
2699