xref: /openbmc/linux/fs/xfs/libxfs/xfs_attr_leaf.c (revision de528723)
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_sb.h"
14 #include "xfs_mount.h"
15 #include "xfs_da_format.h"
16 #include "xfs_da_btree.h"
17 #include "xfs_inode.h"
18 #include "xfs_trans.h"
19 #include "xfs_bmap_btree.h"
20 #include "xfs_bmap.h"
21 #include "xfs_attr_sf.h"
22 #include "xfs_attr_remote.h"
23 #include "xfs_attr.h"
24 #include "xfs_attr_leaf.h"
25 #include "xfs_error.h"
26 #include "xfs_trace.h"
27 #include "xfs_buf_item.h"
28 #include "xfs_dir2.h"
29 #include "xfs_log.h"
30 
31 
32 /*
33  * xfs_attr_leaf.c
34  *
35  * Routines to implement leaf blocks of attributes as Btrees of hashed names.
36  */
37 
38 /*========================================================================
39  * Function prototypes for the kernel.
40  *========================================================================*/
41 
42 /*
43  * Routines used for growing the Btree.
44  */
45 STATIC int xfs_attr3_leaf_create(struct xfs_da_args *args,
46 				 xfs_dablk_t which_block, struct xfs_buf **bpp);
47 STATIC int xfs_attr3_leaf_add_work(struct xfs_buf *leaf_buffer,
48 				   struct xfs_attr3_icleaf_hdr *ichdr,
49 				   struct xfs_da_args *args, int freemap_index);
50 STATIC void xfs_attr3_leaf_compact(struct xfs_da_args *args,
51 				   struct xfs_attr3_icleaf_hdr *ichdr,
52 				   struct xfs_buf *leaf_buffer);
53 STATIC void xfs_attr3_leaf_rebalance(xfs_da_state_t *state,
54 						   xfs_da_state_blk_t *blk1,
55 						   xfs_da_state_blk_t *blk2);
56 STATIC int xfs_attr3_leaf_figure_balance(xfs_da_state_t *state,
57 			xfs_da_state_blk_t *leaf_blk_1,
58 			struct xfs_attr3_icleaf_hdr *ichdr1,
59 			xfs_da_state_blk_t *leaf_blk_2,
60 			struct xfs_attr3_icleaf_hdr *ichdr2,
61 			int *number_entries_in_blk1,
62 			int *number_usedbytes_in_blk1);
63 
64 /*
65  * Utility routines.
66  */
67 STATIC void xfs_attr3_leaf_moveents(struct xfs_da_args *args,
68 			struct xfs_attr_leafblock *src_leaf,
69 			struct xfs_attr3_icleaf_hdr *src_ichdr, int src_start,
70 			struct xfs_attr_leafblock *dst_leaf,
71 			struct xfs_attr3_icleaf_hdr *dst_ichdr, int dst_start,
72 			int move_count);
73 STATIC int xfs_attr_leaf_entsize(xfs_attr_leafblock_t *leaf, int index);
74 
75 /*
76  * attr3 block 'firstused' conversion helpers.
77  *
78  * firstused refers to the offset of the first used byte of the nameval region
79  * of an attr leaf block. The region starts at the tail of the block and expands
80  * backwards towards the middle. As such, firstused is initialized to the block
81  * size for an empty leaf block and is reduced from there.
82  *
83  * The attr3 block size is pegged to the fsb size and the maximum fsb is 64k.
84  * The in-core firstused field is 32-bit and thus supports the maximum fsb size.
85  * The on-disk field is only 16-bit, however, and overflows at 64k. Since this
86  * only occurs at exactly 64k, we use zero as a magic on-disk value to represent
87  * the attr block size. The following helpers manage the conversion between the
88  * in-core and on-disk formats.
89  */
90 
91 static void
92 xfs_attr3_leaf_firstused_from_disk(
93 	struct xfs_da_geometry		*geo,
94 	struct xfs_attr3_icleaf_hdr	*to,
95 	struct xfs_attr_leafblock	*from)
96 {
97 	struct xfs_attr3_leaf_hdr	*hdr3;
98 
99 	if (from->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC)) {
100 		hdr3 = (struct xfs_attr3_leaf_hdr *) from;
101 		to->firstused = be16_to_cpu(hdr3->firstused);
102 	} else {
103 		to->firstused = be16_to_cpu(from->hdr.firstused);
104 	}
105 
106 	/*
107 	 * Convert from the magic fsb size value to actual blocksize. This
108 	 * should only occur for empty blocks when the block size overflows
109 	 * 16-bits.
110 	 */
111 	if (to->firstused == XFS_ATTR3_LEAF_NULLOFF) {
112 		ASSERT(!to->count && !to->usedbytes);
113 		ASSERT(geo->blksize > USHRT_MAX);
114 		to->firstused = geo->blksize;
115 	}
116 }
117 
118 static void
119 xfs_attr3_leaf_firstused_to_disk(
120 	struct xfs_da_geometry		*geo,
121 	struct xfs_attr_leafblock	*to,
122 	struct xfs_attr3_icleaf_hdr	*from)
123 {
124 	struct xfs_attr3_leaf_hdr	*hdr3;
125 	uint32_t			firstused;
126 
127 	/* magic value should only be seen on disk */
128 	ASSERT(from->firstused != XFS_ATTR3_LEAF_NULLOFF);
129 
130 	/*
131 	 * Scale down the 32-bit in-core firstused value to the 16-bit on-disk
132 	 * value. This only overflows at the max supported value of 64k. Use the
133 	 * magic on-disk value to represent block size in this case.
134 	 */
135 	firstused = from->firstused;
136 	if (firstused > USHRT_MAX) {
137 		ASSERT(from->firstused == geo->blksize);
138 		firstused = XFS_ATTR3_LEAF_NULLOFF;
139 	}
140 
141 	if (from->magic == XFS_ATTR3_LEAF_MAGIC) {
142 		hdr3 = (struct xfs_attr3_leaf_hdr *) to;
143 		hdr3->firstused = cpu_to_be16(firstused);
144 	} else {
145 		to->hdr.firstused = cpu_to_be16(firstused);
146 	}
147 }
148 
149 void
150 xfs_attr3_leaf_hdr_from_disk(
151 	struct xfs_da_geometry		*geo,
152 	struct xfs_attr3_icleaf_hdr	*to,
153 	struct xfs_attr_leafblock	*from)
154 {
155 	int	i;
156 
157 	ASSERT(from->hdr.info.magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
158 	       from->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
159 
160 	if (from->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC)) {
161 		struct xfs_attr3_leaf_hdr *hdr3 = (struct xfs_attr3_leaf_hdr *)from;
162 
163 		to->forw = be32_to_cpu(hdr3->info.hdr.forw);
164 		to->back = be32_to_cpu(hdr3->info.hdr.back);
165 		to->magic = be16_to_cpu(hdr3->info.hdr.magic);
166 		to->count = be16_to_cpu(hdr3->count);
167 		to->usedbytes = be16_to_cpu(hdr3->usedbytes);
168 		xfs_attr3_leaf_firstused_from_disk(geo, to, from);
169 		to->holes = hdr3->holes;
170 
171 		for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
172 			to->freemap[i].base = be16_to_cpu(hdr3->freemap[i].base);
173 			to->freemap[i].size = be16_to_cpu(hdr3->freemap[i].size);
174 		}
175 		return;
176 	}
177 	to->forw = be32_to_cpu(from->hdr.info.forw);
178 	to->back = be32_to_cpu(from->hdr.info.back);
179 	to->magic = be16_to_cpu(from->hdr.info.magic);
180 	to->count = be16_to_cpu(from->hdr.count);
181 	to->usedbytes = be16_to_cpu(from->hdr.usedbytes);
182 	xfs_attr3_leaf_firstused_from_disk(geo, to, from);
183 	to->holes = from->hdr.holes;
184 
185 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
186 		to->freemap[i].base = be16_to_cpu(from->hdr.freemap[i].base);
187 		to->freemap[i].size = be16_to_cpu(from->hdr.freemap[i].size);
188 	}
189 }
190 
191 void
192 xfs_attr3_leaf_hdr_to_disk(
193 	struct xfs_da_geometry		*geo,
194 	struct xfs_attr_leafblock	*to,
195 	struct xfs_attr3_icleaf_hdr	*from)
196 {
197 	int				i;
198 
199 	ASSERT(from->magic == XFS_ATTR_LEAF_MAGIC ||
200 	       from->magic == XFS_ATTR3_LEAF_MAGIC);
201 
202 	if (from->magic == XFS_ATTR3_LEAF_MAGIC) {
203 		struct xfs_attr3_leaf_hdr *hdr3 = (struct xfs_attr3_leaf_hdr *)to;
204 
205 		hdr3->info.hdr.forw = cpu_to_be32(from->forw);
206 		hdr3->info.hdr.back = cpu_to_be32(from->back);
207 		hdr3->info.hdr.magic = cpu_to_be16(from->magic);
208 		hdr3->count = cpu_to_be16(from->count);
209 		hdr3->usedbytes = cpu_to_be16(from->usedbytes);
210 		xfs_attr3_leaf_firstused_to_disk(geo, to, from);
211 		hdr3->holes = from->holes;
212 		hdr3->pad1 = 0;
213 
214 		for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
215 			hdr3->freemap[i].base = cpu_to_be16(from->freemap[i].base);
216 			hdr3->freemap[i].size = cpu_to_be16(from->freemap[i].size);
217 		}
218 		return;
219 	}
220 	to->hdr.info.forw = cpu_to_be32(from->forw);
221 	to->hdr.info.back = cpu_to_be32(from->back);
222 	to->hdr.info.magic = cpu_to_be16(from->magic);
223 	to->hdr.count = cpu_to_be16(from->count);
224 	to->hdr.usedbytes = cpu_to_be16(from->usedbytes);
225 	xfs_attr3_leaf_firstused_to_disk(geo, to, from);
226 	to->hdr.holes = from->holes;
227 	to->hdr.pad1 = 0;
228 
229 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
230 		to->hdr.freemap[i].base = cpu_to_be16(from->freemap[i].base);
231 		to->hdr.freemap[i].size = cpu_to_be16(from->freemap[i].size);
232 	}
233 }
234 
235 static xfs_failaddr_t
236 xfs_attr3_leaf_verify(
237 	struct xfs_buf			*bp)
238 {
239 	struct xfs_attr3_icleaf_hdr	ichdr;
240 	struct xfs_mount		*mp = bp->b_mount;
241 	struct xfs_attr_leafblock	*leaf = bp->b_addr;
242 	struct xfs_attr_leaf_entry	*entries;
243 	uint32_t			end;	/* must be 32bit - see below */
244 	int				i;
245 	xfs_failaddr_t			fa;
246 
247 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
248 
249 	fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
250 	if (fa)
251 		return fa;
252 
253 	/*
254 	 * In recovery there is a transient state where count == 0 is valid
255 	 * because we may have transitioned an empty shortform attr to a leaf
256 	 * if the attr didn't fit in shortform.
257 	 */
258 	if (!xfs_log_in_recovery(mp) && ichdr.count == 0)
259 		return __this_address;
260 
261 	/*
262 	 * firstused is the block offset of the first name info structure.
263 	 * Make sure it doesn't go off the block or crash into the header.
264 	 */
265 	if (ichdr.firstused > mp->m_attr_geo->blksize)
266 		return __this_address;
267 	if (ichdr.firstused < xfs_attr3_leaf_hdr_size(leaf))
268 		return __this_address;
269 
270 	/* Make sure the entries array doesn't crash into the name info. */
271 	entries = xfs_attr3_leaf_entryp(bp->b_addr);
272 	if ((char *)&entries[ichdr.count] >
273 	    (char *)bp->b_addr + ichdr.firstused)
274 		return __this_address;
275 
276 	/* XXX: need to range check rest of attr header values */
277 	/* XXX: hash order check? */
278 
279 	/*
280 	 * Quickly check the freemap information.  Attribute data has to be
281 	 * aligned to 4-byte boundaries, and likewise for the free space.
282 	 *
283 	 * Note that for 64k block size filesystems, the freemap entries cannot
284 	 * overflow as they are only be16 fields. However, when checking end
285 	 * pointer of the freemap, we have to be careful to detect overflows and
286 	 * so use uint32_t for those checks.
287 	 */
288 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
289 		if (ichdr.freemap[i].base > mp->m_attr_geo->blksize)
290 			return __this_address;
291 		if (ichdr.freemap[i].base & 0x3)
292 			return __this_address;
293 		if (ichdr.freemap[i].size > mp->m_attr_geo->blksize)
294 			return __this_address;
295 		if (ichdr.freemap[i].size & 0x3)
296 			return __this_address;
297 
298 		/* be care of 16 bit overflows here */
299 		end = (uint32_t)ichdr.freemap[i].base + ichdr.freemap[i].size;
300 		if (end < ichdr.freemap[i].base)
301 			return __this_address;
302 		if (end > mp->m_attr_geo->blksize)
303 			return __this_address;
304 	}
305 
306 	return NULL;
307 }
308 
309 static void
310 xfs_attr3_leaf_write_verify(
311 	struct xfs_buf	*bp)
312 {
313 	struct xfs_mount	*mp = bp->b_mount;
314 	struct xfs_buf_log_item	*bip = bp->b_log_item;
315 	struct xfs_attr3_leaf_hdr *hdr3 = bp->b_addr;
316 	xfs_failaddr_t		fa;
317 
318 	fa = xfs_attr3_leaf_verify(bp);
319 	if (fa) {
320 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
321 		return;
322 	}
323 
324 	if (!xfs_sb_version_hascrc(&mp->m_sb))
325 		return;
326 
327 	if (bip)
328 		hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
329 
330 	xfs_buf_update_cksum(bp, XFS_ATTR3_LEAF_CRC_OFF);
331 }
332 
333 /*
334  * leaf/node format detection on trees is sketchy, so a node read can be done on
335  * leaf level blocks when detection identifies the tree as a node format tree
336  * incorrectly. In this case, we need to swap the verifier to match the correct
337  * format of the block being read.
338  */
339 static void
340 xfs_attr3_leaf_read_verify(
341 	struct xfs_buf		*bp)
342 {
343 	struct xfs_mount	*mp = bp->b_mount;
344 	xfs_failaddr_t		fa;
345 
346 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
347 	     !xfs_buf_verify_cksum(bp, XFS_ATTR3_LEAF_CRC_OFF))
348 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
349 	else {
350 		fa = xfs_attr3_leaf_verify(bp);
351 		if (fa)
352 			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
353 	}
354 }
355 
356 const struct xfs_buf_ops xfs_attr3_leaf_buf_ops = {
357 	.name = "xfs_attr3_leaf",
358 	.magic16 = { cpu_to_be16(XFS_ATTR_LEAF_MAGIC),
359 		     cpu_to_be16(XFS_ATTR3_LEAF_MAGIC) },
360 	.verify_read = xfs_attr3_leaf_read_verify,
361 	.verify_write = xfs_attr3_leaf_write_verify,
362 	.verify_struct = xfs_attr3_leaf_verify,
363 };
364 
365 int
366 xfs_attr3_leaf_read(
367 	struct xfs_trans	*tp,
368 	struct xfs_inode	*dp,
369 	xfs_dablk_t		bno,
370 	xfs_daddr_t		mappedbno,
371 	struct xfs_buf		**bpp)
372 {
373 	int			err;
374 
375 	err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
376 				XFS_ATTR_FORK, &xfs_attr3_leaf_buf_ops);
377 	if (!err && tp && *bpp)
378 		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_ATTR_LEAF_BUF);
379 	return err;
380 }
381 
382 /*========================================================================
383  * Namespace helper routines
384  *========================================================================*/
385 
386 /*
387  * If namespace bits don't match return 0.
388  * If all match then return 1.
389  */
390 STATIC int
391 xfs_attr_namesp_match(int arg_flags, int ondisk_flags)
392 {
393 	return XFS_ATTR_NSP_ONDISK(ondisk_flags) == XFS_ATTR_NSP_ARGS_TO_ONDISK(arg_flags);
394 }
395 
396 static int
397 xfs_attr_copy_value(
398 	struct xfs_da_args	*args,
399 	unsigned char		*value,
400 	int			valuelen)
401 {
402 	/*
403 	 * No copy if all we have to do is get the length
404 	 */
405 	if (args->flags & ATTR_KERNOVAL) {
406 		args->valuelen = valuelen;
407 		return 0;
408 	}
409 
410 	/*
411 	 * No copy if the length of the existing buffer is too small
412 	 */
413 	if (args->valuelen < valuelen) {
414 		args->valuelen = valuelen;
415 		return -ERANGE;
416 	}
417 
418 	if (args->op_flags & XFS_DA_OP_ALLOCVAL) {
419 		args->value = kmem_alloc_large(valuelen, 0);
420 		if (!args->value)
421 			return -ENOMEM;
422 	}
423 	args->valuelen = valuelen;
424 
425 	/* remote block xattr requires IO for copy-in */
426 	if (args->rmtblkno)
427 		return xfs_attr_rmtval_get(args);
428 
429 	/*
430 	 * This is to prevent a GCC warning because the remote xattr case
431 	 * doesn't have a value to pass in. In that case, we never reach here,
432 	 * but GCC can't work that out and so throws a "passing NULL to
433 	 * memcpy" warning.
434 	 */
435 	if (!value)
436 		return -EINVAL;
437 	memcpy(args->value, value, valuelen);
438 	return 0;
439 }
440 
441 /*========================================================================
442  * External routines when attribute fork size < XFS_LITINO(mp).
443  *========================================================================*/
444 
445 /*
446  * Query whether the requested number of additional bytes of extended
447  * attribute space will be able to fit inline.
448  *
449  * Returns zero if not, else the di_forkoff fork offset to be used in the
450  * literal area for attribute data once the new bytes have been added.
451  *
452  * di_forkoff must be 8 byte aligned, hence is stored as a >>3 value;
453  * special case for dev/uuid inodes, they have fixed size data forks.
454  */
455 int
456 xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes)
457 {
458 	int offset;
459 	int minforkoff;	/* lower limit on valid forkoff locations */
460 	int maxforkoff;	/* upper limit on valid forkoff locations */
461 	int dsize;
462 	xfs_mount_t *mp = dp->i_mount;
463 
464 	/* rounded down */
465 	offset = (XFS_LITINO(mp, dp->i_d.di_version) - bytes) >> 3;
466 
467 	if (dp->i_d.di_format == XFS_DINODE_FMT_DEV) {
468 		minforkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
469 		return (offset >= minforkoff) ? minforkoff : 0;
470 	}
471 
472 	/*
473 	 * If the requested numbers of bytes is smaller or equal to the
474 	 * current attribute fork size we can always proceed.
475 	 *
476 	 * Note that if_bytes in the data fork might actually be larger than
477 	 * the current data fork size is due to delalloc extents. In that
478 	 * case either the extent count will go down when they are converted
479 	 * to real extents, or the delalloc conversion will take care of the
480 	 * literal area rebalancing.
481 	 */
482 	if (bytes <= XFS_IFORK_ASIZE(dp))
483 		return dp->i_d.di_forkoff;
484 
485 	/*
486 	 * For attr2 we can try to move the forkoff if there is space in the
487 	 * literal area, but for the old format we are done if there is no
488 	 * space in the fixed attribute fork.
489 	 */
490 	if (!(mp->m_flags & XFS_MOUNT_ATTR2))
491 		return 0;
492 
493 	dsize = dp->i_df.if_bytes;
494 
495 	switch (dp->i_d.di_format) {
496 	case XFS_DINODE_FMT_EXTENTS:
497 		/*
498 		 * If there is no attr fork and the data fork is extents,
499 		 * determine if creating the default attr fork will result
500 		 * in the extents form migrating to btree. If so, the
501 		 * minimum offset only needs to be the space required for
502 		 * the btree root.
503 		 */
504 		if (!dp->i_d.di_forkoff && dp->i_df.if_bytes >
505 		    xfs_default_attroffset(dp))
506 			dsize = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
507 		break;
508 	case XFS_DINODE_FMT_BTREE:
509 		/*
510 		 * If we have a data btree then keep forkoff if we have one,
511 		 * otherwise we are adding a new attr, so then we set
512 		 * minforkoff to where the btree root can finish so we have
513 		 * plenty of room for attrs
514 		 */
515 		if (dp->i_d.di_forkoff) {
516 			if (offset < dp->i_d.di_forkoff)
517 				return 0;
518 			return dp->i_d.di_forkoff;
519 		}
520 		dsize = XFS_BMAP_BROOT_SPACE(mp, dp->i_df.if_broot);
521 		break;
522 	}
523 
524 	/*
525 	 * A data fork btree root must have space for at least
526 	 * MINDBTPTRS key/ptr pairs if the data fork is small or empty.
527 	 */
528 	minforkoff = max(dsize, XFS_BMDR_SPACE_CALC(MINDBTPTRS));
529 	minforkoff = roundup(minforkoff, 8) >> 3;
530 
531 	/* attr fork btree root can have at least this many key/ptr pairs */
532 	maxforkoff = XFS_LITINO(mp, dp->i_d.di_version) -
533 			XFS_BMDR_SPACE_CALC(MINABTPTRS);
534 	maxforkoff = maxforkoff >> 3;	/* rounded down */
535 
536 	if (offset >= maxforkoff)
537 		return maxforkoff;
538 	if (offset >= minforkoff)
539 		return offset;
540 	return 0;
541 }
542 
543 /*
544  * Switch on the ATTR2 superblock bit (implies also FEATURES2)
545  */
546 STATIC void
547 xfs_sbversion_add_attr2(xfs_mount_t *mp, xfs_trans_t *tp)
548 {
549 	if ((mp->m_flags & XFS_MOUNT_ATTR2) &&
550 	    !(xfs_sb_version_hasattr2(&mp->m_sb))) {
551 		spin_lock(&mp->m_sb_lock);
552 		if (!xfs_sb_version_hasattr2(&mp->m_sb)) {
553 			xfs_sb_version_addattr2(&mp->m_sb);
554 			spin_unlock(&mp->m_sb_lock);
555 			xfs_log_sb(tp);
556 		} else
557 			spin_unlock(&mp->m_sb_lock);
558 	}
559 }
560 
561 /*
562  * Create the initial contents of a shortform attribute list.
563  */
564 void
565 xfs_attr_shortform_create(xfs_da_args_t *args)
566 {
567 	xfs_attr_sf_hdr_t *hdr;
568 	xfs_inode_t *dp;
569 	struct xfs_ifork *ifp;
570 
571 	trace_xfs_attr_sf_create(args);
572 
573 	dp = args->dp;
574 	ASSERT(dp != NULL);
575 	ifp = dp->i_afp;
576 	ASSERT(ifp != NULL);
577 	ASSERT(ifp->if_bytes == 0);
578 	if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS) {
579 		ifp->if_flags &= ~XFS_IFEXTENTS;	/* just in case */
580 		dp->i_d.di_aformat = XFS_DINODE_FMT_LOCAL;
581 		ifp->if_flags |= XFS_IFINLINE;
582 	} else {
583 		ASSERT(ifp->if_flags & XFS_IFINLINE);
584 	}
585 	xfs_idata_realloc(dp, sizeof(*hdr), XFS_ATTR_FORK);
586 	hdr = (xfs_attr_sf_hdr_t *)ifp->if_u1.if_data;
587 	hdr->count = 0;
588 	hdr->totsize = cpu_to_be16(sizeof(*hdr));
589 	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_ADATA);
590 }
591 
592 /*
593  * Add a name/value pair to the shortform attribute list.
594  * Overflow from the inode has already been checked for.
595  */
596 void
597 xfs_attr_shortform_add(xfs_da_args_t *args, int forkoff)
598 {
599 	xfs_attr_shortform_t *sf;
600 	xfs_attr_sf_entry_t *sfe;
601 	int i, offset, size;
602 	xfs_mount_t *mp;
603 	xfs_inode_t *dp;
604 	struct xfs_ifork *ifp;
605 
606 	trace_xfs_attr_sf_add(args);
607 
608 	dp = args->dp;
609 	mp = dp->i_mount;
610 	dp->i_d.di_forkoff = forkoff;
611 
612 	ifp = dp->i_afp;
613 	ASSERT(ifp->if_flags & XFS_IFINLINE);
614 	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
615 	sfe = &sf->list[0];
616 	for (i = 0; i < sf->hdr.count; sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
617 #ifdef DEBUG
618 		if (sfe->namelen != args->namelen)
619 			continue;
620 		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
621 			continue;
622 		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
623 			continue;
624 		ASSERT(0);
625 #endif
626 	}
627 
628 	offset = (char *)sfe - (char *)sf;
629 	size = XFS_ATTR_SF_ENTSIZE_BYNAME(args->namelen, args->valuelen);
630 	xfs_idata_realloc(dp, size, XFS_ATTR_FORK);
631 	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
632 	sfe = (xfs_attr_sf_entry_t *)((char *)sf + offset);
633 
634 	sfe->namelen = args->namelen;
635 	sfe->valuelen = args->valuelen;
636 	sfe->flags = XFS_ATTR_NSP_ARGS_TO_ONDISK(args->flags);
637 	memcpy(sfe->nameval, args->name, args->namelen);
638 	memcpy(&sfe->nameval[args->namelen], args->value, args->valuelen);
639 	sf->hdr.count++;
640 	be16_add_cpu(&sf->hdr.totsize, size);
641 	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_ADATA);
642 
643 	xfs_sbversion_add_attr2(mp, args->trans);
644 }
645 
646 /*
647  * After the last attribute is removed revert to original inode format,
648  * making all literal area available to the data fork once more.
649  */
650 void
651 xfs_attr_fork_remove(
652 	struct xfs_inode	*ip,
653 	struct xfs_trans	*tp)
654 {
655 	xfs_idestroy_fork(ip, XFS_ATTR_FORK);
656 	ip->i_d.di_forkoff = 0;
657 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
658 
659 	ASSERT(ip->i_d.di_anextents == 0);
660 	ASSERT(ip->i_afp == NULL);
661 
662 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
663 }
664 
665 /*
666  * Remove an attribute from the shortform attribute list structure.
667  */
668 int
669 xfs_attr_shortform_remove(xfs_da_args_t *args)
670 {
671 	xfs_attr_shortform_t *sf;
672 	xfs_attr_sf_entry_t *sfe;
673 	int base, size=0, end, totsize, i;
674 	xfs_mount_t *mp;
675 	xfs_inode_t *dp;
676 
677 	trace_xfs_attr_sf_remove(args);
678 
679 	dp = args->dp;
680 	mp = dp->i_mount;
681 	base = sizeof(xfs_attr_sf_hdr_t);
682 	sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
683 	sfe = &sf->list[0];
684 	end = sf->hdr.count;
685 	for (i = 0; i < end; sfe = XFS_ATTR_SF_NEXTENTRY(sfe),
686 					base += size, i++) {
687 		size = XFS_ATTR_SF_ENTSIZE(sfe);
688 		if (sfe->namelen != args->namelen)
689 			continue;
690 		if (memcmp(sfe->nameval, args->name, args->namelen) != 0)
691 			continue;
692 		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
693 			continue;
694 		break;
695 	}
696 	if (i == end)
697 		return -ENOATTR;
698 
699 	/*
700 	 * Fix up the attribute fork data, covering the hole
701 	 */
702 	end = base + size;
703 	totsize = be16_to_cpu(sf->hdr.totsize);
704 	if (end != totsize)
705 		memmove(&((char *)sf)[base], &((char *)sf)[end], totsize - end);
706 	sf->hdr.count--;
707 	be16_add_cpu(&sf->hdr.totsize, -size);
708 
709 	/*
710 	 * Fix up the start offset of the attribute fork
711 	 */
712 	totsize -= size;
713 	if (totsize == sizeof(xfs_attr_sf_hdr_t) &&
714 	    (mp->m_flags & XFS_MOUNT_ATTR2) &&
715 	    (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
716 	    !(args->op_flags & XFS_DA_OP_ADDNAME)) {
717 		xfs_attr_fork_remove(dp, args->trans);
718 	} else {
719 		xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);
720 		dp->i_d.di_forkoff = xfs_attr_shortform_bytesfit(dp, totsize);
721 		ASSERT(dp->i_d.di_forkoff);
722 		ASSERT(totsize > sizeof(xfs_attr_sf_hdr_t) ||
723 				(args->op_flags & XFS_DA_OP_ADDNAME) ||
724 				!(mp->m_flags & XFS_MOUNT_ATTR2) ||
725 				dp->i_d.di_format == XFS_DINODE_FMT_BTREE);
726 		xfs_trans_log_inode(args->trans, dp,
727 					XFS_ILOG_CORE | XFS_ILOG_ADATA);
728 	}
729 
730 	xfs_sbversion_add_attr2(mp, args->trans);
731 
732 	return 0;
733 }
734 
735 /*
736  * Look up a name in a shortform attribute list structure.
737  */
738 /*ARGSUSED*/
739 int
740 xfs_attr_shortform_lookup(xfs_da_args_t *args)
741 {
742 	xfs_attr_shortform_t *sf;
743 	xfs_attr_sf_entry_t *sfe;
744 	int i;
745 	struct xfs_ifork *ifp;
746 
747 	trace_xfs_attr_sf_lookup(args);
748 
749 	ifp = args->dp->i_afp;
750 	ASSERT(ifp->if_flags & XFS_IFINLINE);
751 	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
752 	sfe = &sf->list[0];
753 	for (i = 0; i < sf->hdr.count;
754 				sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
755 		if (sfe->namelen != args->namelen)
756 			continue;
757 		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
758 			continue;
759 		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
760 			continue;
761 		return -EEXIST;
762 	}
763 	return -ENOATTR;
764 }
765 
766 /*
767  * Retreive the attribute value and length.
768  *
769  * If ATTR_KERNOVAL is specified, only the length needs to be returned.
770  * Unlike a lookup, we only return an error if the attribute does not
771  * exist or we can't retrieve the value.
772  */
773 int
774 xfs_attr_shortform_getvalue(
775 	struct xfs_da_args	*args)
776 {
777 	struct xfs_attr_shortform *sf;
778 	struct xfs_attr_sf_entry *sfe;
779 	int			i;
780 
781 	ASSERT(args->dp->i_afp->if_flags == XFS_IFINLINE);
782 	sf = (xfs_attr_shortform_t *)args->dp->i_afp->if_u1.if_data;
783 	sfe = &sf->list[0];
784 	for (i = 0; i < sf->hdr.count;
785 				sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
786 		if (sfe->namelen != args->namelen)
787 			continue;
788 		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
789 			continue;
790 		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
791 			continue;
792 		return xfs_attr_copy_value(args, &sfe->nameval[args->namelen],
793 						sfe->valuelen);
794 	}
795 	return -ENOATTR;
796 }
797 
798 /*
799  * Convert from using the shortform to the leaf.  On success, return the
800  * buffer so that we can keep it locked until we're totally done with it.
801  */
802 int
803 xfs_attr_shortform_to_leaf(
804 	struct xfs_da_args		*args,
805 	struct xfs_buf			**leaf_bp)
806 {
807 	struct xfs_inode		*dp;
808 	struct xfs_attr_shortform	*sf;
809 	struct xfs_attr_sf_entry	*sfe;
810 	struct xfs_da_args		nargs;
811 	char				*tmpbuffer;
812 	int				error, i, size;
813 	xfs_dablk_t			blkno;
814 	struct xfs_buf			*bp;
815 	struct xfs_ifork		*ifp;
816 
817 	trace_xfs_attr_sf_to_leaf(args);
818 
819 	dp = args->dp;
820 	ifp = dp->i_afp;
821 	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
822 	size = be16_to_cpu(sf->hdr.totsize);
823 	tmpbuffer = kmem_alloc(size, 0);
824 	ASSERT(tmpbuffer != NULL);
825 	memcpy(tmpbuffer, ifp->if_u1.if_data, size);
826 	sf = (xfs_attr_shortform_t *)tmpbuffer;
827 
828 	xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);
829 	xfs_bmap_local_to_extents_empty(args->trans, dp, XFS_ATTR_FORK);
830 
831 	bp = NULL;
832 	error = xfs_da_grow_inode(args, &blkno);
833 	if (error)
834 		goto out;
835 
836 	ASSERT(blkno == 0);
837 	error = xfs_attr3_leaf_create(args, blkno, &bp);
838 	if (error)
839 		goto out;
840 
841 	memset((char *)&nargs, 0, sizeof(nargs));
842 	nargs.dp = dp;
843 	nargs.geo = args->geo;
844 	nargs.total = args->total;
845 	nargs.whichfork = XFS_ATTR_FORK;
846 	nargs.trans = args->trans;
847 	nargs.op_flags = XFS_DA_OP_OKNOENT;
848 
849 	sfe = &sf->list[0];
850 	for (i = 0; i < sf->hdr.count; i++) {
851 		nargs.name = sfe->nameval;
852 		nargs.namelen = sfe->namelen;
853 		nargs.value = &sfe->nameval[nargs.namelen];
854 		nargs.valuelen = sfe->valuelen;
855 		nargs.hashval = xfs_da_hashname(sfe->nameval,
856 						sfe->namelen);
857 		nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(sfe->flags);
858 		error = xfs_attr3_leaf_lookup_int(bp, &nargs); /* set a->index */
859 		ASSERT(error == -ENOATTR);
860 		error = xfs_attr3_leaf_add(bp, &nargs);
861 		ASSERT(error != -ENOSPC);
862 		if (error)
863 			goto out;
864 		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
865 	}
866 	error = 0;
867 	*leaf_bp = bp;
868 out:
869 	kmem_free(tmpbuffer);
870 	return error;
871 }
872 
873 /*
874  * Check a leaf attribute block to see if all the entries would fit into
875  * a shortform attribute list.
876  */
877 int
878 xfs_attr_shortform_allfit(
879 	struct xfs_buf		*bp,
880 	struct xfs_inode	*dp)
881 {
882 	struct xfs_attr_leafblock *leaf;
883 	struct xfs_attr_leaf_entry *entry;
884 	xfs_attr_leaf_name_local_t *name_loc;
885 	struct xfs_attr3_icleaf_hdr leafhdr;
886 	int			bytes;
887 	int			i;
888 	struct xfs_mount	*mp = bp->b_mount;
889 
890 	leaf = bp->b_addr;
891 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
892 	entry = xfs_attr3_leaf_entryp(leaf);
893 
894 	bytes = sizeof(struct xfs_attr_sf_hdr);
895 	for (i = 0; i < leafhdr.count; entry++, i++) {
896 		if (entry->flags & XFS_ATTR_INCOMPLETE)
897 			continue;		/* don't copy partial entries */
898 		if (!(entry->flags & XFS_ATTR_LOCAL))
899 			return 0;
900 		name_loc = xfs_attr3_leaf_name_local(leaf, i);
901 		if (name_loc->namelen >= XFS_ATTR_SF_ENTSIZE_MAX)
902 			return 0;
903 		if (be16_to_cpu(name_loc->valuelen) >= XFS_ATTR_SF_ENTSIZE_MAX)
904 			return 0;
905 		bytes += sizeof(struct xfs_attr_sf_entry) - 1
906 				+ name_loc->namelen
907 				+ be16_to_cpu(name_loc->valuelen);
908 	}
909 	if ((dp->i_mount->m_flags & XFS_MOUNT_ATTR2) &&
910 	    (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
911 	    (bytes == sizeof(struct xfs_attr_sf_hdr)))
912 		return -1;
913 	return xfs_attr_shortform_bytesfit(dp, bytes);
914 }
915 
916 /* Verify the consistency of an inline attribute fork. */
917 xfs_failaddr_t
918 xfs_attr_shortform_verify(
919 	struct xfs_inode		*ip)
920 {
921 	struct xfs_attr_shortform	*sfp;
922 	struct xfs_attr_sf_entry	*sfep;
923 	struct xfs_attr_sf_entry	*next_sfep;
924 	char				*endp;
925 	struct xfs_ifork		*ifp;
926 	int				i;
927 	int				size;
928 
929 	ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL);
930 	ifp = XFS_IFORK_PTR(ip, XFS_ATTR_FORK);
931 	sfp = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
932 	size = ifp->if_bytes;
933 
934 	/*
935 	 * Give up if the attribute is way too short.
936 	 */
937 	if (size < sizeof(struct xfs_attr_sf_hdr))
938 		return __this_address;
939 
940 	endp = (char *)sfp + size;
941 
942 	/* Check all reported entries */
943 	sfep = &sfp->list[0];
944 	for (i = 0; i < sfp->hdr.count; i++) {
945 		/*
946 		 * struct xfs_attr_sf_entry has a variable length.
947 		 * Check the fixed-offset parts of the structure are
948 		 * within the data buffer.
949 		 */
950 		if (((char *)sfep + sizeof(*sfep)) >= endp)
951 			return __this_address;
952 
953 		/* Don't allow names with known bad length. */
954 		if (sfep->namelen == 0)
955 			return __this_address;
956 
957 		/*
958 		 * Check that the variable-length part of the structure is
959 		 * within the data buffer.  The next entry starts after the
960 		 * name component, so nextentry is an acceptable test.
961 		 */
962 		next_sfep = XFS_ATTR_SF_NEXTENTRY(sfep);
963 		if ((char *)next_sfep > endp)
964 			return __this_address;
965 
966 		/*
967 		 * Check for unknown flags.  Short form doesn't support
968 		 * the incomplete or local bits, so we can use the namespace
969 		 * mask here.
970 		 */
971 		if (sfep->flags & ~XFS_ATTR_NSP_ONDISK_MASK)
972 			return __this_address;
973 
974 		/*
975 		 * Check for invalid namespace combinations.  We only allow
976 		 * one namespace flag per xattr, so we can just count the
977 		 * bits (i.e. hweight) here.
978 		 */
979 		if (hweight8(sfep->flags & XFS_ATTR_NSP_ONDISK_MASK) > 1)
980 			return __this_address;
981 
982 		sfep = next_sfep;
983 	}
984 	if ((void *)sfep != (void *)endp)
985 		return __this_address;
986 
987 	return NULL;
988 }
989 
990 /*
991  * Convert a leaf attribute list to shortform attribute list
992  */
993 int
994 xfs_attr3_leaf_to_shortform(
995 	struct xfs_buf		*bp,
996 	struct xfs_da_args	*args,
997 	int			forkoff)
998 {
999 	struct xfs_attr_leafblock *leaf;
1000 	struct xfs_attr3_icleaf_hdr ichdr;
1001 	struct xfs_attr_leaf_entry *entry;
1002 	struct xfs_attr_leaf_name_local *name_loc;
1003 	struct xfs_da_args	nargs;
1004 	struct xfs_inode	*dp = args->dp;
1005 	char			*tmpbuffer;
1006 	int			error;
1007 	int			i;
1008 
1009 	trace_xfs_attr_leaf_to_sf(args);
1010 
1011 	tmpbuffer = kmem_alloc(args->geo->blksize, 0);
1012 	if (!tmpbuffer)
1013 		return -ENOMEM;
1014 
1015 	memcpy(tmpbuffer, bp->b_addr, args->geo->blksize);
1016 
1017 	leaf = (xfs_attr_leafblock_t *)tmpbuffer;
1018 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
1019 	entry = xfs_attr3_leaf_entryp(leaf);
1020 
1021 	/* XXX (dgc): buffer is about to be marked stale - why zero it? */
1022 	memset(bp->b_addr, 0, args->geo->blksize);
1023 
1024 	/*
1025 	 * Clean out the prior contents of the attribute list.
1026 	 */
1027 	error = xfs_da_shrink_inode(args, 0, bp);
1028 	if (error)
1029 		goto out;
1030 
1031 	if (forkoff == -1) {
1032 		ASSERT(dp->i_mount->m_flags & XFS_MOUNT_ATTR2);
1033 		ASSERT(dp->i_d.di_format != XFS_DINODE_FMT_BTREE);
1034 		xfs_attr_fork_remove(dp, args->trans);
1035 		goto out;
1036 	}
1037 
1038 	xfs_attr_shortform_create(args);
1039 
1040 	/*
1041 	 * Copy the attributes
1042 	 */
1043 	memset((char *)&nargs, 0, sizeof(nargs));
1044 	nargs.geo = args->geo;
1045 	nargs.dp = dp;
1046 	nargs.total = args->total;
1047 	nargs.whichfork = XFS_ATTR_FORK;
1048 	nargs.trans = args->trans;
1049 	nargs.op_flags = XFS_DA_OP_OKNOENT;
1050 
1051 	for (i = 0; i < ichdr.count; entry++, i++) {
1052 		if (entry->flags & XFS_ATTR_INCOMPLETE)
1053 			continue;	/* don't copy partial entries */
1054 		if (!entry->nameidx)
1055 			continue;
1056 		ASSERT(entry->flags & XFS_ATTR_LOCAL);
1057 		name_loc = xfs_attr3_leaf_name_local(leaf, i);
1058 		nargs.name = name_loc->nameval;
1059 		nargs.namelen = name_loc->namelen;
1060 		nargs.value = &name_loc->nameval[nargs.namelen];
1061 		nargs.valuelen = be16_to_cpu(name_loc->valuelen);
1062 		nargs.hashval = be32_to_cpu(entry->hashval);
1063 		nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(entry->flags);
1064 		xfs_attr_shortform_add(&nargs, forkoff);
1065 	}
1066 	error = 0;
1067 
1068 out:
1069 	kmem_free(tmpbuffer);
1070 	return error;
1071 }
1072 
1073 /*
1074  * Convert from using a single leaf to a root node and a leaf.
1075  */
1076 int
1077 xfs_attr3_leaf_to_node(
1078 	struct xfs_da_args	*args)
1079 {
1080 	struct xfs_attr_leafblock *leaf;
1081 	struct xfs_attr3_icleaf_hdr icleafhdr;
1082 	struct xfs_attr_leaf_entry *entries;
1083 	struct xfs_da_node_entry *btree;
1084 	struct xfs_da3_icnode_hdr icnodehdr;
1085 	struct xfs_da_intnode	*node;
1086 	struct xfs_inode	*dp = args->dp;
1087 	struct xfs_mount	*mp = dp->i_mount;
1088 	struct xfs_buf		*bp1 = NULL;
1089 	struct xfs_buf		*bp2 = NULL;
1090 	xfs_dablk_t		blkno;
1091 	int			error;
1092 
1093 	trace_xfs_attr_leaf_to_node(args);
1094 
1095 	error = xfs_da_grow_inode(args, &blkno);
1096 	if (error)
1097 		goto out;
1098 	error = xfs_attr3_leaf_read(args->trans, dp, 0, -1, &bp1);
1099 	if (error)
1100 		goto out;
1101 
1102 	error = xfs_da_get_buf(args->trans, dp, blkno, -1, &bp2, XFS_ATTR_FORK);
1103 	if (error)
1104 		goto out;
1105 
1106 	/* copy leaf to new buffer, update identifiers */
1107 	xfs_trans_buf_set_type(args->trans, bp2, XFS_BLFT_ATTR_LEAF_BUF);
1108 	bp2->b_ops = bp1->b_ops;
1109 	memcpy(bp2->b_addr, bp1->b_addr, args->geo->blksize);
1110 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
1111 		struct xfs_da3_blkinfo *hdr3 = bp2->b_addr;
1112 		hdr3->blkno = cpu_to_be64(bp2->b_bn);
1113 	}
1114 	xfs_trans_log_buf(args->trans, bp2, 0, args->geo->blksize - 1);
1115 
1116 	/*
1117 	 * Set up the new root node.
1118 	 */
1119 	error = xfs_da3_node_create(args, 0, 1, &bp1, XFS_ATTR_FORK);
1120 	if (error)
1121 		goto out;
1122 	node = bp1->b_addr;
1123 	dp->d_ops->node_hdr_from_disk(&icnodehdr, node);
1124 	btree = dp->d_ops->node_tree_p(node);
1125 
1126 	leaf = bp2->b_addr;
1127 	xfs_attr3_leaf_hdr_from_disk(args->geo, &icleafhdr, leaf);
1128 	entries = xfs_attr3_leaf_entryp(leaf);
1129 
1130 	/* both on-disk, don't endian-flip twice */
1131 	btree[0].hashval = entries[icleafhdr.count - 1].hashval;
1132 	btree[0].before = cpu_to_be32(blkno);
1133 	icnodehdr.count = 1;
1134 	dp->d_ops->node_hdr_to_disk(node, &icnodehdr);
1135 	xfs_trans_log_buf(args->trans, bp1, 0, args->geo->blksize - 1);
1136 	error = 0;
1137 out:
1138 	return error;
1139 }
1140 
1141 /*========================================================================
1142  * Routines used for growing the Btree.
1143  *========================================================================*/
1144 
1145 /*
1146  * Create the initial contents of a leaf attribute list
1147  * or a leaf in a node attribute list.
1148  */
1149 STATIC int
1150 xfs_attr3_leaf_create(
1151 	struct xfs_da_args	*args,
1152 	xfs_dablk_t		blkno,
1153 	struct xfs_buf		**bpp)
1154 {
1155 	struct xfs_attr_leafblock *leaf;
1156 	struct xfs_attr3_icleaf_hdr ichdr;
1157 	struct xfs_inode	*dp = args->dp;
1158 	struct xfs_mount	*mp = dp->i_mount;
1159 	struct xfs_buf		*bp;
1160 	int			error;
1161 
1162 	trace_xfs_attr_leaf_create(args);
1163 
1164 	error = xfs_da_get_buf(args->trans, args->dp, blkno, -1, &bp,
1165 					    XFS_ATTR_FORK);
1166 	if (error)
1167 		return error;
1168 	bp->b_ops = &xfs_attr3_leaf_buf_ops;
1169 	xfs_trans_buf_set_type(args->trans, bp, XFS_BLFT_ATTR_LEAF_BUF);
1170 	leaf = bp->b_addr;
1171 	memset(leaf, 0, args->geo->blksize);
1172 
1173 	memset(&ichdr, 0, sizeof(ichdr));
1174 	ichdr.firstused = args->geo->blksize;
1175 
1176 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
1177 		struct xfs_da3_blkinfo *hdr3 = bp->b_addr;
1178 
1179 		ichdr.magic = XFS_ATTR3_LEAF_MAGIC;
1180 
1181 		hdr3->blkno = cpu_to_be64(bp->b_bn);
1182 		hdr3->owner = cpu_to_be64(dp->i_ino);
1183 		uuid_copy(&hdr3->uuid, &mp->m_sb.sb_meta_uuid);
1184 
1185 		ichdr.freemap[0].base = sizeof(struct xfs_attr3_leaf_hdr);
1186 	} else {
1187 		ichdr.magic = XFS_ATTR_LEAF_MAGIC;
1188 		ichdr.freemap[0].base = sizeof(struct xfs_attr_leaf_hdr);
1189 	}
1190 	ichdr.freemap[0].size = ichdr.firstused - ichdr.freemap[0].base;
1191 
1192 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf, &ichdr);
1193 	xfs_trans_log_buf(args->trans, bp, 0, args->geo->blksize - 1);
1194 
1195 	*bpp = bp;
1196 	return 0;
1197 }
1198 
1199 /*
1200  * Split the leaf node, rebalance, then add the new entry.
1201  */
1202 int
1203 xfs_attr3_leaf_split(
1204 	struct xfs_da_state	*state,
1205 	struct xfs_da_state_blk	*oldblk,
1206 	struct xfs_da_state_blk	*newblk)
1207 {
1208 	xfs_dablk_t blkno;
1209 	int error;
1210 
1211 	trace_xfs_attr_leaf_split(state->args);
1212 
1213 	/*
1214 	 * Allocate space for a new leaf node.
1215 	 */
1216 	ASSERT(oldblk->magic == XFS_ATTR_LEAF_MAGIC);
1217 	error = xfs_da_grow_inode(state->args, &blkno);
1218 	if (error)
1219 		return error;
1220 	error = xfs_attr3_leaf_create(state->args, blkno, &newblk->bp);
1221 	if (error)
1222 		return error;
1223 	newblk->blkno = blkno;
1224 	newblk->magic = XFS_ATTR_LEAF_MAGIC;
1225 
1226 	/*
1227 	 * Rebalance the entries across the two leaves.
1228 	 * NOTE: rebalance() currently depends on the 2nd block being empty.
1229 	 */
1230 	xfs_attr3_leaf_rebalance(state, oldblk, newblk);
1231 	error = xfs_da3_blk_link(state, oldblk, newblk);
1232 	if (error)
1233 		return error;
1234 
1235 	/*
1236 	 * Save info on "old" attribute for "atomic rename" ops, leaf_add()
1237 	 * modifies the index/blkno/rmtblk/rmtblkcnt fields to show the
1238 	 * "new" attrs info.  Will need the "old" info to remove it later.
1239 	 *
1240 	 * Insert the "new" entry in the correct block.
1241 	 */
1242 	if (state->inleaf) {
1243 		trace_xfs_attr_leaf_add_old(state->args);
1244 		error = xfs_attr3_leaf_add(oldblk->bp, state->args);
1245 	} else {
1246 		trace_xfs_attr_leaf_add_new(state->args);
1247 		error = xfs_attr3_leaf_add(newblk->bp, state->args);
1248 	}
1249 
1250 	/*
1251 	 * Update last hashval in each block since we added the name.
1252 	 */
1253 	oldblk->hashval = xfs_attr_leaf_lasthash(oldblk->bp, NULL);
1254 	newblk->hashval = xfs_attr_leaf_lasthash(newblk->bp, NULL);
1255 	return error;
1256 }
1257 
1258 /*
1259  * Add a name to the leaf attribute list structure.
1260  */
1261 int
1262 xfs_attr3_leaf_add(
1263 	struct xfs_buf		*bp,
1264 	struct xfs_da_args	*args)
1265 {
1266 	struct xfs_attr_leafblock *leaf;
1267 	struct xfs_attr3_icleaf_hdr ichdr;
1268 	int			tablesize;
1269 	int			entsize;
1270 	int			sum;
1271 	int			tmp;
1272 	int			i;
1273 
1274 	trace_xfs_attr_leaf_add(args);
1275 
1276 	leaf = bp->b_addr;
1277 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
1278 	ASSERT(args->index >= 0 && args->index <= ichdr.count);
1279 	entsize = xfs_attr_leaf_newentsize(args, NULL);
1280 
1281 	/*
1282 	 * Search through freemap for first-fit on new name length.
1283 	 * (may need to figure in size of entry struct too)
1284 	 */
1285 	tablesize = (ichdr.count + 1) * sizeof(xfs_attr_leaf_entry_t)
1286 					+ xfs_attr3_leaf_hdr_size(leaf);
1287 	for (sum = 0, i = XFS_ATTR_LEAF_MAPSIZE - 1; i >= 0; i--) {
1288 		if (tablesize > ichdr.firstused) {
1289 			sum += ichdr.freemap[i].size;
1290 			continue;
1291 		}
1292 		if (!ichdr.freemap[i].size)
1293 			continue;	/* no space in this map */
1294 		tmp = entsize;
1295 		if (ichdr.freemap[i].base < ichdr.firstused)
1296 			tmp += sizeof(xfs_attr_leaf_entry_t);
1297 		if (ichdr.freemap[i].size >= tmp) {
1298 			tmp = xfs_attr3_leaf_add_work(bp, &ichdr, args, i);
1299 			goto out_log_hdr;
1300 		}
1301 		sum += ichdr.freemap[i].size;
1302 	}
1303 
1304 	/*
1305 	 * If there are no holes in the address space of the block,
1306 	 * and we don't have enough freespace, then compaction will do us
1307 	 * no good and we should just give up.
1308 	 */
1309 	if (!ichdr.holes && sum < entsize)
1310 		return -ENOSPC;
1311 
1312 	/*
1313 	 * Compact the entries to coalesce free space.
1314 	 * This may change the hdr->count via dropping INCOMPLETE entries.
1315 	 */
1316 	xfs_attr3_leaf_compact(args, &ichdr, bp);
1317 
1318 	/*
1319 	 * After compaction, the block is guaranteed to have only one
1320 	 * free region, in freemap[0].  If it is not big enough, give up.
1321 	 */
1322 	if (ichdr.freemap[0].size < (entsize + sizeof(xfs_attr_leaf_entry_t))) {
1323 		tmp = -ENOSPC;
1324 		goto out_log_hdr;
1325 	}
1326 
1327 	tmp = xfs_attr3_leaf_add_work(bp, &ichdr, args, 0);
1328 
1329 out_log_hdr:
1330 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf, &ichdr);
1331 	xfs_trans_log_buf(args->trans, bp,
1332 		XFS_DA_LOGRANGE(leaf, &leaf->hdr,
1333 				xfs_attr3_leaf_hdr_size(leaf)));
1334 	return tmp;
1335 }
1336 
1337 /*
1338  * Add a name to a leaf attribute list structure.
1339  */
1340 STATIC int
1341 xfs_attr3_leaf_add_work(
1342 	struct xfs_buf		*bp,
1343 	struct xfs_attr3_icleaf_hdr *ichdr,
1344 	struct xfs_da_args	*args,
1345 	int			mapindex)
1346 {
1347 	struct xfs_attr_leafblock *leaf;
1348 	struct xfs_attr_leaf_entry *entry;
1349 	struct xfs_attr_leaf_name_local *name_loc;
1350 	struct xfs_attr_leaf_name_remote *name_rmt;
1351 	struct xfs_mount	*mp;
1352 	int			tmp;
1353 	int			i;
1354 
1355 	trace_xfs_attr_leaf_add_work(args);
1356 
1357 	leaf = bp->b_addr;
1358 	ASSERT(mapindex >= 0 && mapindex < XFS_ATTR_LEAF_MAPSIZE);
1359 	ASSERT(args->index >= 0 && args->index <= ichdr->count);
1360 
1361 	/*
1362 	 * Force open some space in the entry array and fill it in.
1363 	 */
1364 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
1365 	if (args->index < ichdr->count) {
1366 		tmp  = ichdr->count - args->index;
1367 		tmp *= sizeof(xfs_attr_leaf_entry_t);
1368 		memmove(entry + 1, entry, tmp);
1369 		xfs_trans_log_buf(args->trans, bp,
1370 		    XFS_DA_LOGRANGE(leaf, entry, tmp + sizeof(*entry)));
1371 	}
1372 	ichdr->count++;
1373 
1374 	/*
1375 	 * Allocate space for the new string (at the end of the run).
1376 	 */
1377 	mp = args->trans->t_mountp;
1378 	ASSERT(ichdr->freemap[mapindex].base < args->geo->blksize);
1379 	ASSERT((ichdr->freemap[mapindex].base & 0x3) == 0);
1380 	ASSERT(ichdr->freemap[mapindex].size >=
1381 		xfs_attr_leaf_newentsize(args, NULL));
1382 	ASSERT(ichdr->freemap[mapindex].size < args->geo->blksize);
1383 	ASSERT((ichdr->freemap[mapindex].size & 0x3) == 0);
1384 
1385 	ichdr->freemap[mapindex].size -= xfs_attr_leaf_newentsize(args, &tmp);
1386 
1387 	entry->nameidx = cpu_to_be16(ichdr->freemap[mapindex].base +
1388 				     ichdr->freemap[mapindex].size);
1389 	entry->hashval = cpu_to_be32(args->hashval);
1390 	entry->flags = tmp ? XFS_ATTR_LOCAL : 0;
1391 	entry->flags |= XFS_ATTR_NSP_ARGS_TO_ONDISK(args->flags);
1392 	if (args->op_flags & XFS_DA_OP_RENAME) {
1393 		entry->flags |= XFS_ATTR_INCOMPLETE;
1394 		if ((args->blkno2 == args->blkno) &&
1395 		    (args->index2 <= args->index)) {
1396 			args->index2++;
1397 		}
1398 	}
1399 	xfs_trans_log_buf(args->trans, bp,
1400 			  XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
1401 	ASSERT((args->index == 0) ||
1402 	       (be32_to_cpu(entry->hashval) >= be32_to_cpu((entry-1)->hashval)));
1403 	ASSERT((args->index == ichdr->count - 1) ||
1404 	       (be32_to_cpu(entry->hashval) <= be32_to_cpu((entry+1)->hashval)));
1405 
1406 	/*
1407 	 * For "remote" attribute values, simply note that we need to
1408 	 * allocate space for the "remote" value.  We can't actually
1409 	 * allocate the extents in this transaction, and we can't decide
1410 	 * which blocks they should be as we might allocate more blocks
1411 	 * as part of this transaction (a split operation for example).
1412 	 */
1413 	if (entry->flags & XFS_ATTR_LOCAL) {
1414 		name_loc = xfs_attr3_leaf_name_local(leaf, args->index);
1415 		name_loc->namelen = args->namelen;
1416 		name_loc->valuelen = cpu_to_be16(args->valuelen);
1417 		memcpy((char *)name_loc->nameval, args->name, args->namelen);
1418 		memcpy((char *)&name_loc->nameval[args->namelen], args->value,
1419 				   be16_to_cpu(name_loc->valuelen));
1420 	} else {
1421 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
1422 		name_rmt->namelen = args->namelen;
1423 		memcpy((char *)name_rmt->name, args->name, args->namelen);
1424 		entry->flags |= XFS_ATTR_INCOMPLETE;
1425 		/* just in case */
1426 		name_rmt->valuelen = 0;
1427 		name_rmt->valueblk = 0;
1428 		args->rmtblkno = 1;
1429 		args->rmtblkcnt = xfs_attr3_rmt_blocks(mp, args->valuelen);
1430 		args->rmtvaluelen = args->valuelen;
1431 	}
1432 	xfs_trans_log_buf(args->trans, bp,
1433 	     XFS_DA_LOGRANGE(leaf, xfs_attr3_leaf_name(leaf, args->index),
1434 				   xfs_attr_leaf_entsize(leaf, args->index)));
1435 
1436 	/*
1437 	 * Update the control info for this leaf node
1438 	 */
1439 	if (be16_to_cpu(entry->nameidx) < ichdr->firstused)
1440 		ichdr->firstused = be16_to_cpu(entry->nameidx);
1441 
1442 	ASSERT(ichdr->firstused >= ichdr->count * sizeof(xfs_attr_leaf_entry_t)
1443 					+ xfs_attr3_leaf_hdr_size(leaf));
1444 	tmp = (ichdr->count - 1) * sizeof(xfs_attr_leaf_entry_t)
1445 					+ xfs_attr3_leaf_hdr_size(leaf);
1446 
1447 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
1448 		if (ichdr->freemap[i].base == tmp) {
1449 			ichdr->freemap[i].base += sizeof(xfs_attr_leaf_entry_t);
1450 			ichdr->freemap[i].size -= sizeof(xfs_attr_leaf_entry_t);
1451 		}
1452 	}
1453 	ichdr->usedbytes += xfs_attr_leaf_entsize(leaf, args->index);
1454 	return 0;
1455 }
1456 
1457 /*
1458  * Garbage collect a leaf attribute list block by copying it to a new buffer.
1459  */
1460 STATIC void
1461 xfs_attr3_leaf_compact(
1462 	struct xfs_da_args	*args,
1463 	struct xfs_attr3_icleaf_hdr *ichdr_dst,
1464 	struct xfs_buf		*bp)
1465 {
1466 	struct xfs_attr_leafblock *leaf_src;
1467 	struct xfs_attr_leafblock *leaf_dst;
1468 	struct xfs_attr3_icleaf_hdr ichdr_src;
1469 	struct xfs_trans	*trans = args->trans;
1470 	char			*tmpbuffer;
1471 
1472 	trace_xfs_attr_leaf_compact(args);
1473 
1474 	tmpbuffer = kmem_alloc(args->geo->blksize, 0);
1475 	memcpy(tmpbuffer, bp->b_addr, args->geo->blksize);
1476 	memset(bp->b_addr, 0, args->geo->blksize);
1477 	leaf_src = (xfs_attr_leafblock_t *)tmpbuffer;
1478 	leaf_dst = bp->b_addr;
1479 
1480 	/*
1481 	 * Copy the on-disk header back into the destination buffer to ensure
1482 	 * all the information in the header that is not part of the incore
1483 	 * header structure is preserved.
1484 	 */
1485 	memcpy(bp->b_addr, tmpbuffer, xfs_attr3_leaf_hdr_size(leaf_src));
1486 
1487 	/* Initialise the incore headers */
1488 	ichdr_src = *ichdr_dst;	/* struct copy */
1489 	ichdr_dst->firstused = args->geo->blksize;
1490 	ichdr_dst->usedbytes = 0;
1491 	ichdr_dst->count = 0;
1492 	ichdr_dst->holes = 0;
1493 	ichdr_dst->freemap[0].base = xfs_attr3_leaf_hdr_size(leaf_src);
1494 	ichdr_dst->freemap[0].size = ichdr_dst->firstused -
1495 						ichdr_dst->freemap[0].base;
1496 
1497 	/* write the header back to initialise the underlying buffer */
1498 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf_dst, ichdr_dst);
1499 
1500 	/*
1501 	 * Copy all entry's in the same (sorted) order,
1502 	 * but allocate name/value pairs packed and in sequence.
1503 	 */
1504 	xfs_attr3_leaf_moveents(args, leaf_src, &ichdr_src, 0,
1505 				leaf_dst, ichdr_dst, 0, ichdr_src.count);
1506 	/*
1507 	 * this logs the entire buffer, but the caller must write the header
1508 	 * back to the buffer when it is finished modifying it.
1509 	 */
1510 	xfs_trans_log_buf(trans, bp, 0, args->geo->blksize - 1);
1511 
1512 	kmem_free(tmpbuffer);
1513 }
1514 
1515 /*
1516  * Compare two leaf blocks "order".
1517  * Return 0 unless leaf2 should go before leaf1.
1518  */
1519 static int
1520 xfs_attr3_leaf_order(
1521 	struct xfs_buf	*leaf1_bp,
1522 	struct xfs_attr3_icleaf_hdr *leaf1hdr,
1523 	struct xfs_buf	*leaf2_bp,
1524 	struct xfs_attr3_icleaf_hdr *leaf2hdr)
1525 {
1526 	struct xfs_attr_leaf_entry *entries1;
1527 	struct xfs_attr_leaf_entry *entries2;
1528 
1529 	entries1 = xfs_attr3_leaf_entryp(leaf1_bp->b_addr);
1530 	entries2 = xfs_attr3_leaf_entryp(leaf2_bp->b_addr);
1531 	if (leaf1hdr->count > 0 && leaf2hdr->count > 0 &&
1532 	    ((be32_to_cpu(entries2[0].hashval) <
1533 	      be32_to_cpu(entries1[0].hashval)) ||
1534 	     (be32_to_cpu(entries2[leaf2hdr->count - 1].hashval) <
1535 	      be32_to_cpu(entries1[leaf1hdr->count - 1].hashval)))) {
1536 		return 1;
1537 	}
1538 	return 0;
1539 }
1540 
1541 int
1542 xfs_attr_leaf_order(
1543 	struct xfs_buf	*leaf1_bp,
1544 	struct xfs_buf	*leaf2_bp)
1545 {
1546 	struct xfs_attr3_icleaf_hdr ichdr1;
1547 	struct xfs_attr3_icleaf_hdr ichdr2;
1548 	struct xfs_mount *mp = leaf1_bp->b_mount;
1549 
1550 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr1, leaf1_bp->b_addr);
1551 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr2, leaf2_bp->b_addr);
1552 	return xfs_attr3_leaf_order(leaf1_bp, &ichdr1, leaf2_bp, &ichdr2);
1553 }
1554 
1555 /*
1556  * Redistribute the attribute list entries between two leaf nodes,
1557  * taking into account the size of the new entry.
1558  *
1559  * NOTE: if new block is empty, then it will get the upper half of the
1560  * old block.  At present, all (one) callers pass in an empty second block.
1561  *
1562  * This code adjusts the args->index/blkno and args->index2/blkno2 fields
1563  * to match what it is doing in splitting the attribute leaf block.  Those
1564  * values are used in "atomic rename" operations on attributes.  Note that
1565  * the "new" and "old" values can end up in different blocks.
1566  */
1567 STATIC void
1568 xfs_attr3_leaf_rebalance(
1569 	struct xfs_da_state	*state,
1570 	struct xfs_da_state_blk	*blk1,
1571 	struct xfs_da_state_blk	*blk2)
1572 {
1573 	struct xfs_da_args	*args;
1574 	struct xfs_attr_leafblock *leaf1;
1575 	struct xfs_attr_leafblock *leaf2;
1576 	struct xfs_attr3_icleaf_hdr ichdr1;
1577 	struct xfs_attr3_icleaf_hdr ichdr2;
1578 	struct xfs_attr_leaf_entry *entries1;
1579 	struct xfs_attr_leaf_entry *entries2;
1580 	int			count;
1581 	int			totallen;
1582 	int			max;
1583 	int			space;
1584 	int			swap;
1585 
1586 	/*
1587 	 * Set up environment.
1588 	 */
1589 	ASSERT(blk1->magic == XFS_ATTR_LEAF_MAGIC);
1590 	ASSERT(blk2->magic == XFS_ATTR_LEAF_MAGIC);
1591 	leaf1 = blk1->bp->b_addr;
1592 	leaf2 = blk2->bp->b_addr;
1593 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr1, leaf1);
1594 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr2, leaf2);
1595 	ASSERT(ichdr2.count == 0);
1596 	args = state->args;
1597 
1598 	trace_xfs_attr_leaf_rebalance(args);
1599 
1600 	/*
1601 	 * Check ordering of blocks, reverse if it makes things simpler.
1602 	 *
1603 	 * NOTE: Given that all (current) callers pass in an empty
1604 	 * second block, this code should never set "swap".
1605 	 */
1606 	swap = 0;
1607 	if (xfs_attr3_leaf_order(blk1->bp, &ichdr1, blk2->bp, &ichdr2)) {
1608 		swap(blk1, blk2);
1609 
1610 		/* swap structures rather than reconverting them */
1611 		swap(ichdr1, ichdr2);
1612 
1613 		leaf1 = blk1->bp->b_addr;
1614 		leaf2 = blk2->bp->b_addr;
1615 		swap = 1;
1616 	}
1617 
1618 	/*
1619 	 * Examine entries until we reduce the absolute difference in
1620 	 * byte usage between the two blocks to a minimum.  Then get
1621 	 * the direction to copy and the number of elements to move.
1622 	 *
1623 	 * "inleaf" is true if the new entry should be inserted into blk1.
1624 	 * If "swap" is also true, then reverse the sense of "inleaf".
1625 	 */
1626 	state->inleaf = xfs_attr3_leaf_figure_balance(state, blk1, &ichdr1,
1627 						      blk2, &ichdr2,
1628 						      &count, &totallen);
1629 	if (swap)
1630 		state->inleaf = !state->inleaf;
1631 
1632 	/*
1633 	 * Move any entries required from leaf to leaf:
1634 	 */
1635 	if (count < ichdr1.count) {
1636 		/*
1637 		 * Figure the total bytes to be added to the destination leaf.
1638 		 */
1639 		/* number entries being moved */
1640 		count = ichdr1.count - count;
1641 		space  = ichdr1.usedbytes - totallen;
1642 		space += count * sizeof(xfs_attr_leaf_entry_t);
1643 
1644 		/*
1645 		 * leaf2 is the destination, compact it if it looks tight.
1646 		 */
1647 		max  = ichdr2.firstused - xfs_attr3_leaf_hdr_size(leaf1);
1648 		max -= ichdr2.count * sizeof(xfs_attr_leaf_entry_t);
1649 		if (space > max)
1650 			xfs_attr3_leaf_compact(args, &ichdr2, blk2->bp);
1651 
1652 		/*
1653 		 * Move high entries from leaf1 to low end of leaf2.
1654 		 */
1655 		xfs_attr3_leaf_moveents(args, leaf1, &ichdr1,
1656 				ichdr1.count - count, leaf2, &ichdr2, 0, count);
1657 
1658 	} else if (count > ichdr1.count) {
1659 		/*
1660 		 * I assert that since all callers pass in an empty
1661 		 * second buffer, this code should never execute.
1662 		 */
1663 		ASSERT(0);
1664 
1665 		/*
1666 		 * Figure the total bytes to be added to the destination leaf.
1667 		 */
1668 		/* number entries being moved */
1669 		count -= ichdr1.count;
1670 		space  = totallen - ichdr1.usedbytes;
1671 		space += count * sizeof(xfs_attr_leaf_entry_t);
1672 
1673 		/*
1674 		 * leaf1 is the destination, compact it if it looks tight.
1675 		 */
1676 		max  = ichdr1.firstused - xfs_attr3_leaf_hdr_size(leaf1);
1677 		max -= ichdr1.count * sizeof(xfs_attr_leaf_entry_t);
1678 		if (space > max)
1679 			xfs_attr3_leaf_compact(args, &ichdr1, blk1->bp);
1680 
1681 		/*
1682 		 * Move low entries from leaf2 to high end of leaf1.
1683 		 */
1684 		xfs_attr3_leaf_moveents(args, leaf2, &ichdr2, 0, leaf1, &ichdr1,
1685 					ichdr1.count, count);
1686 	}
1687 
1688 	xfs_attr3_leaf_hdr_to_disk(state->args->geo, leaf1, &ichdr1);
1689 	xfs_attr3_leaf_hdr_to_disk(state->args->geo, leaf2, &ichdr2);
1690 	xfs_trans_log_buf(args->trans, blk1->bp, 0, args->geo->blksize - 1);
1691 	xfs_trans_log_buf(args->trans, blk2->bp, 0, args->geo->blksize - 1);
1692 
1693 	/*
1694 	 * Copy out last hashval in each block for B-tree code.
1695 	 */
1696 	entries1 = xfs_attr3_leaf_entryp(leaf1);
1697 	entries2 = xfs_attr3_leaf_entryp(leaf2);
1698 	blk1->hashval = be32_to_cpu(entries1[ichdr1.count - 1].hashval);
1699 	blk2->hashval = be32_to_cpu(entries2[ichdr2.count - 1].hashval);
1700 
1701 	/*
1702 	 * Adjust the expected index for insertion.
1703 	 * NOTE: this code depends on the (current) situation that the
1704 	 * second block was originally empty.
1705 	 *
1706 	 * If the insertion point moved to the 2nd block, we must adjust
1707 	 * the index.  We must also track the entry just following the
1708 	 * new entry for use in an "atomic rename" operation, that entry
1709 	 * is always the "old" entry and the "new" entry is what we are
1710 	 * inserting.  The index/blkno fields refer to the "old" entry,
1711 	 * while the index2/blkno2 fields refer to the "new" entry.
1712 	 */
1713 	if (blk1->index > ichdr1.count) {
1714 		ASSERT(state->inleaf == 0);
1715 		blk2->index = blk1->index - ichdr1.count;
1716 		args->index = args->index2 = blk2->index;
1717 		args->blkno = args->blkno2 = blk2->blkno;
1718 	} else if (blk1->index == ichdr1.count) {
1719 		if (state->inleaf) {
1720 			args->index = blk1->index;
1721 			args->blkno = blk1->blkno;
1722 			args->index2 = 0;
1723 			args->blkno2 = blk2->blkno;
1724 		} else {
1725 			/*
1726 			 * On a double leaf split, the original attr location
1727 			 * is already stored in blkno2/index2, so don't
1728 			 * overwrite it overwise we corrupt the tree.
1729 			 */
1730 			blk2->index = blk1->index - ichdr1.count;
1731 			args->index = blk2->index;
1732 			args->blkno = blk2->blkno;
1733 			if (!state->extravalid) {
1734 				/*
1735 				 * set the new attr location to match the old
1736 				 * one and let the higher level split code
1737 				 * decide where in the leaf to place it.
1738 				 */
1739 				args->index2 = blk2->index;
1740 				args->blkno2 = blk2->blkno;
1741 			}
1742 		}
1743 	} else {
1744 		ASSERT(state->inleaf == 1);
1745 		args->index = args->index2 = blk1->index;
1746 		args->blkno = args->blkno2 = blk1->blkno;
1747 	}
1748 }
1749 
1750 /*
1751  * Examine entries until we reduce the absolute difference in
1752  * byte usage between the two blocks to a minimum.
1753  * GROT: Is this really necessary?  With other than a 512 byte blocksize,
1754  * GROT: there will always be enough room in either block for a new entry.
1755  * GROT: Do a double-split for this case?
1756  */
1757 STATIC int
1758 xfs_attr3_leaf_figure_balance(
1759 	struct xfs_da_state		*state,
1760 	struct xfs_da_state_blk		*blk1,
1761 	struct xfs_attr3_icleaf_hdr	*ichdr1,
1762 	struct xfs_da_state_blk		*blk2,
1763 	struct xfs_attr3_icleaf_hdr	*ichdr2,
1764 	int				*countarg,
1765 	int				*usedbytesarg)
1766 {
1767 	struct xfs_attr_leafblock	*leaf1 = blk1->bp->b_addr;
1768 	struct xfs_attr_leafblock	*leaf2 = blk2->bp->b_addr;
1769 	struct xfs_attr_leaf_entry	*entry;
1770 	int				count;
1771 	int				max;
1772 	int				index;
1773 	int				totallen = 0;
1774 	int				half;
1775 	int				lastdelta;
1776 	int				foundit = 0;
1777 	int				tmp;
1778 
1779 	/*
1780 	 * Examine entries until we reduce the absolute difference in
1781 	 * byte usage between the two blocks to a minimum.
1782 	 */
1783 	max = ichdr1->count + ichdr2->count;
1784 	half = (max + 1) * sizeof(*entry);
1785 	half += ichdr1->usedbytes + ichdr2->usedbytes +
1786 			xfs_attr_leaf_newentsize(state->args, NULL);
1787 	half /= 2;
1788 	lastdelta = state->args->geo->blksize;
1789 	entry = xfs_attr3_leaf_entryp(leaf1);
1790 	for (count = index = 0; count < max; entry++, index++, count++) {
1791 
1792 #define XFS_ATTR_ABS(A)	(((A) < 0) ? -(A) : (A))
1793 		/*
1794 		 * The new entry is in the first block, account for it.
1795 		 */
1796 		if (count == blk1->index) {
1797 			tmp = totallen + sizeof(*entry) +
1798 				xfs_attr_leaf_newentsize(state->args, NULL);
1799 			if (XFS_ATTR_ABS(half - tmp) > lastdelta)
1800 				break;
1801 			lastdelta = XFS_ATTR_ABS(half - tmp);
1802 			totallen = tmp;
1803 			foundit = 1;
1804 		}
1805 
1806 		/*
1807 		 * Wrap around into the second block if necessary.
1808 		 */
1809 		if (count == ichdr1->count) {
1810 			leaf1 = leaf2;
1811 			entry = xfs_attr3_leaf_entryp(leaf1);
1812 			index = 0;
1813 		}
1814 
1815 		/*
1816 		 * Figure out if next leaf entry would be too much.
1817 		 */
1818 		tmp = totallen + sizeof(*entry) + xfs_attr_leaf_entsize(leaf1,
1819 									index);
1820 		if (XFS_ATTR_ABS(half - tmp) > lastdelta)
1821 			break;
1822 		lastdelta = XFS_ATTR_ABS(half - tmp);
1823 		totallen = tmp;
1824 #undef XFS_ATTR_ABS
1825 	}
1826 
1827 	/*
1828 	 * Calculate the number of usedbytes that will end up in lower block.
1829 	 * If new entry not in lower block, fix up the count.
1830 	 */
1831 	totallen -= count * sizeof(*entry);
1832 	if (foundit) {
1833 		totallen -= sizeof(*entry) +
1834 				xfs_attr_leaf_newentsize(state->args, NULL);
1835 	}
1836 
1837 	*countarg = count;
1838 	*usedbytesarg = totallen;
1839 	return foundit;
1840 }
1841 
1842 /*========================================================================
1843  * Routines used for shrinking the Btree.
1844  *========================================================================*/
1845 
1846 /*
1847  * Check a leaf block and its neighbors to see if the block should be
1848  * collapsed into one or the other neighbor.  Always keep the block
1849  * with the smaller block number.
1850  * If the current block is over 50% full, don't try to join it, return 0.
1851  * If the block is empty, fill in the state structure and return 2.
1852  * If it can be collapsed, fill in the state structure and return 1.
1853  * If nothing can be done, return 0.
1854  *
1855  * GROT: allow for INCOMPLETE entries in calculation.
1856  */
1857 int
1858 xfs_attr3_leaf_toosmall(
1859 	struct xfs_da_state	*state,
1860 	int			*action)
1861 {
1862 	struct xfs_attr_leafblock *leaf;
1863 	struct xfs_da_state_blk	*blk;
1864 	struct xfs_attr3_icleaf_hdr ichdr;
1865 	struct xfs_buf		*bp;
1866 	xfs_dablk_t		blkno;
1867 	int			bytes;
1868 	int			forward;
1869 	int			error;
1870 	int			retval;
1871 	int			i;
1872 
1873 	trace_xfs_attr_leaf_toosmall(state->args);
1874 
1875 	/*
1876 	 * Check for the degenerate case of the block being over 50% full.
1877 	 * If so, it's not worth even looking to see if we might be able
1878 	 * to coalesce with a sibling.
1879 	 */
1880 	blk = &state->path.blk[ state->path.active-1 ];
1881 	leaf = blk->bp->b_addr;
1882 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr, leaf);
1883 	bytes = xfs_attr3_leaf_hdr_size(leaf) +
1884 		ichdr.count * sizeof(xfs_attr_leaf_entry_t) +
1885 		ichdr.usedbytes;
1886 	if (bytes > (state->args->geo->blksize >> 1)) {
1887 		*action = 0;	/* blk over 50%, don't try to join */
1888 		return 0;
1889 	}
1890 
1891 	/*
1892 	 * Check for the degenerate case of the block being empty.
1893 	 * If the block is empty, we'll simply delete it, no need to
1894 	 * coalesce it with a sibling block.  We choose (arbitrarily)
1895 	 * to merge with the forward block unless it is NULL.
1896 	 */
1897 	if (ichdr.count == 0) {
1898 		/*
1899 		 * Make altpath point to the block we want to keep and
1900 		 * path point to the block we want to drop (this one).
1901 		 */
1902 		forward = (ichdr.forw != 0);
1903 		memcpy(&state->altpath, &state->path, sizeof(state->path));
1904 		error = xfs_da3_path_shift(state, &state->altpath, forward,
1905 						 0, &retval);
1906 		if (error)
1907 			return error;
1908 		if (retval) {
1909 			*action = 0;
1910 		} else {
1911 			*action = 2;
1912 		}
1913 		return 0;
1914 	}
1915 
1916 	/*
1917 	 * Examine each sibling block to see if we can coalesce with
1918 	 * at least 25% free space to spare.  We need to figure out
1919 	 * whether to merge with the forward or the backward block.
1920 	 * We prefer coalescing with the lower numbered sibling so as
1921 	 * to shrink an attribute list over time.
1922 	 */
1923 	/* start with smaller blk num */
1924 	forward = ichdr.forw < ichdr.back;
1925 	for (i = 0; i < 2; forward = !forward, i++) {
1926 		struct xfs_attr3_icleaf_hdr ichdr2;
1927 		if (forward)
1928 			blkno = ichdr.forw;
1929 		else
1930 			blkno = ichdr.back;
1931 		if (blkno == 0)
1932 			continue;
1933 		error = xfs_attr3_leaf_read(state->args->trans, state->args->dp,
1934 					blkno, -1, &bp);
1935 		if (error)
1936 			return error;
1937 
1938 		xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr2, bp->b_addr);
1939 
1940 		bytes = state->args->geo->blksize -
1941 			(state->args->geo->blksize >> 2) -
1942 			ichdr.usedbytes - ichdr2.usedbytes -
1943 			((ichdr.count + ichdr2.count) *
1944 					sizeof(xfs_attr_leaf_entry_t)) -
1945 			xfs_attr3_leaf_hdr_size(leaf);
1946 
1947 		xfs_trans_brelse(state->args->trans, bp);
1948 		if (bytes >= 0)
1949 			break;	/* fits with at least 25% to spare */
1950 	}
1951 	if (i >= 2) {
1952 		*action = 0;
1953 		return 0;
1954 	}
1955 
1956 	/*
1957 	 * Make altpath point to the block we want to keep (the lower
1958 	 * numbered block) and path point to the block we want to drop.
1959 	 */
1960 	memcpy(&state->altpath, &state->path, sizeof(state->path));
1961 	if (blkno < blk->blkno) {
1962 		error = xfs_da3_path_shift(state, &state->altpath, forward,
1963 						 0, &retval);
1964 	} else {
1965 		error = xfs_da3_path_shift(state, &state->path, forward,
1966 						 0, &retval);
1967 	}
1968 	if (error)
1969 		return error;
1970 	if (retval) {
1971 		*action = 0;
1972 	} else {
1973 		*action = 1;
1974 	}
1975 	return 0;
1976 }
1977 
1978 /*
1979  * Remove a name from the leaf attribute list structure.
1980  *
1981  * Return 1 if leaf is less than 37% full, 0 if >= 37% full.
1982  * If two leaves are 37% full, when combined they will leave 25% free.
1983  */
1984 int
1985 xfs_attr3_leaf_remove(
1986 	struct xfs_buf		*bp,
1987 	struct xfs_da_args	*args)
1988 {
1989 	struct xfs_attr_leafblock *leaf;
1990 	struct xfs_attr3_icleaf_hdr ichdr;
1991 	struct xfs_attr_leaf_entry *entry;
1992 	int			before;
1993 	int			after;
1994 	int			smallest;
1995 	int			entsize;
1996 	int			tablesize;
1997 	int			tmp;
1998 	int			i;
1999 
2000 	trace_xfs_attr_leaf_remove(args);
2001 
2002 	leaf = bp->b_addr;
2003 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
2004 
2005 	ASSERT(ichdr.count > 0 && ichdr.count < args->geo->blksize / 8);
2006 	ASSERT(args->index >= 0 && args->index < ichdr.count);
2007 	ASSERT(ichdr.firstused >= ichdr.count * sizeof(*entry) +
2008 					xfs_attr3_leaf_hdr_size(leaf));
2009 
2010 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
2011 
2012 	ASSERT(be16_to_cpu(entry->nameidx) >= ichdr.firstused);
2013 	ASSERT(be16_to_cpu(entry->nameidx) < args->geo->blksize);
2014 
2015 	/*
2016 	 * Scan through free region table:
2017 	 *    check for adjacency of free'd entry with an existing one,
2018 	 *    find smallest free region in case we need to replace it,
2019 	 *    adjust any map that borders the entry table,
2020 	 */
2021 	tablesize = ichdr.count * sizeof(xfs_attr_leaf_entry_t)
2022 					+ xfs_attr3_leaf_hdr_size(leaf);
2023 	tmp = ichdr.freemap[0].size;
2024 	before = after = -1;
2025 	smallest = XFS_ATTR_LEAF_MAPSIZE - 1;
2026 	entsize = xfs_attr_leaf_entsize(leaf, args->index);
2027 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
2028 		ASSERT(ichdr.freemap[i].base < args->geo->blksize);
2029 		ASSERT(ichdr.freemap[i].size < args->geo->blksize);
2030 		if (ichdr.freemap[i].base == tablesize) {
2031 			ichdr.freemap[i].base -= sizeof(xfs_attr_leaf_entry_t);
2032 			ichdr.freemap[i].size += sizeof(xfs_attr_leaf_entry_t);
2033 		}
2034 
2035 		if (ichdr.freemap[i].base + ichdr.freemap[i].size ==
2036 				be16_to_cpu(entry->nameidx)) {
2037 			before = i;
2038 		} else if (ichdr.freemap[i].base ==
2039 				(be16_to_cpu(entry->nameidx) + entsize)) {
2040 			after = i;
2041 		} else if (ichdr.freemap[i].size < tmp) {
2042 			tmp = ichdr.freemap[i].size;
2043 			smallest = i;
2044 		}
2045 	}
2046 
2047 	/*
2048 	 * Coalesce adjacent freemap regions,
2049 	 * or replace the smallest region.
2050 	 */
2051 	if ((before >= 0) || (after >= 0)) {
2052 		if ((before >= 0) && (after >= 0)) {
2053 			ichdr.freemap[before].size += entsize;
2054 			ichdr.freemap[before].size += ichdr.freemap[after].size;
2055 			ichdr.freemap[after].base = 0;
2056 			ichdr.freemap[after].size = 0;
2057 		} else if (before >= 0) {
2058 			ichdr.freemap[before].size += entsize;
2059 		} else {
2060 			ichdr.freemap[after].base = be16_to_cpu(entry->nameidx);
2061 			ichdr.freemap[after].size += entsize;
2062 		}
2063 	} else {
2064 		/*
2065 		 * Replace smallest region (if it is smaller than free'd entry)
2066 		 */
2067 		if (ichdr.freemap[smallest].size < entsize) {
2068 			ichdr.freemap[smallest].base = be16_to_cpu(entry->nameidx);
2069 			ichdr.freemap[smallest].size = entsize;
2070 		}
2071 	}
2072 
2073 	/*
2074 	 * Did we remove the first entry?
2075 	 */
2076 	if (be16_to_cpu(entry->nameidx) == ichdr.firstused)
2077 		smallest = 1;
2078 	else
2079 		smallest = 0;
2080 
2081 	/*
2082 	 * Compress the remaining entries and zero out the removed stuff.
2083 	 */
2084 	memset(xfs_attr3_leaf_name(leaf, args->index), 0, entsize);
2085 	ichdr.usedbytes -= entsize;
2086 	xfs_trans_log_buf(args->trans, bp,
2087 	     XFS_DA_LOGRANGE(leaf, xfs_attr3_leaf_name(leaf, args->index),
2088 				   entsize));
2089 
2090 	tmp = (ichdr.count - args->index) * sizeof(xfs_attr_leaf_entry_t);
2091 	memmove(entry, entry + 1, tmp);
2092 	ichdr.count--;
2093 	xfs_trans_log_buf(args->trans, bp,
2094 	    XFS_DA_LOGRANGE(leaf, entry, tmp + sizeof(xfs_attr_leaf_entry_t)));
2095 
2096 	entry = &xfs_attr3_leaf_entryp(leaf)[ichdr.count];
2097 	memset(entry, 0, sizeof(xfs_attr_leaf_entry_t));
2098 
2099 	/*
2100 	 * If we removed the first entry, re-find the first used byte
2101 	 * in the name area.  Note that if the entry was the "firstused",
2102 	 * then we don't have a "hole" in our block resulting from
2103 	 * removing the name.
2104 	 */
2105 	if (smallest) {
2106 		tmp = args->geo->blksize;
2107 		entry = xfs_attr3_leaf_entryp(leaf);
2108 		for (i = ichdr.count - 1; i >= 0; entry++, i--) {
2109 			ASSERT(be16_to_cpu(entry->nameidx) >= ichdr.firstused);
2110 			ASSERT(be16_to_cpu(entry->nameidx) < args->geo->blksize);
2111 
2112 			if (be16_to_cpu(entry->nameidx) < tmp)
2113 				tmp = be16_to_cpu(entry->nameidx);
2114 		}
2115 		ichdr.firstused = tmp;
2116 		ASSERT(ichdr.firstused != 0);
2117 	} else {
2118 		ichdr.holes = 1;	/* mark as needing compaction */
2119 	}
2120 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf, &ichdr);
2121 	xfs_trans_log_buf(args->trans, bp,
2122 			  XFS_DA_LOGRANGE(leaf, &leaf->hdr,
2123 					  xfs_attr3_leaf_hdr_size(leaf)));
2124 
2125 	/*
2126 	 * Check if leaf is less than 50% full, caller may want to
2127 	 * "join" the leaf with a sibling if so.
2128 	 */
2129 	tmp = ichdr.usedbytes + xfs_attr3_leaf_hdr_size(leaf) +
2130 	      ichdr.count * sizeof(xfs_attr_leaf_entry_t);
2131 
2132 	return tmp < args->geo->magicpct; /* leaf is < 37% full */
2133 }
2134 
2135 /*
2136  * Move all the attribute list entries from drop_leaf into save_leaf.
2137  */
2138 void
2139 xfs_attr3_leaf_unbalance(
2140 	struct xfs_da_state	*state,
2141 	struct xfs_da_state_blk	*drop_blk,
2142 	struct xfs_da_state_blk	*save_blk)
2143 {
2144 	struct xfs_attr_leafblock *drop_leaf = drop_blk->bp->b_addr;
2145 	struct xfs_attr_leafblock *save_leaf = save_blk->bp->b_addr;
2146 	struct xfs_attr3_icleaf_hdr drophdr;
2147 	struct xfs_attr3_icleaf_hdr savehdr;
2148 	struct xfs_attr_leaf_entry *entry;
2149 
2150 	trace_xfs_attr_leaf_unbalance(state->args);
2151 
2152 	drop_leaf = drop_blk->bp->b_addr;
2153 	save_leaf = save_blk->bp->b_addr;
2154 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &drophdr, drop_leaf);
2155 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &savehdr, save_leaf);
2156 	entry = xfs_attr3_leaf_entryp(drop_leaf);
2157 
2158 	/*
2159 	 * Save last hashval from dying block for later Btree fixup.
2160 	 */
2161 	drop_blk->hashval = be32_to_cpu(entry[drophdr.count - 1].hashval);
2162 
2163 	/*
2164 	 * Check if we need a temp buffer, or can we do it in place.
2165 	 * Note that we don't check "leaf" for holes because we will
2166 	 * always be dropping it, toosmall() decided that for us already.
2167 	 */
2168 	if (savehdr.holes == 0) {
2169 		/*
2170 		 * dest leaf has no holes, so we add there.  May need
2171 		 * to make some room in the entry array.
2172 		 */
2173 		if (xfs_attr3_leaf_order(save_blk->bp, &savehdr,
2174 					 drop_blk->bp, &drophdr)) {
2175 			xfs_attr3_leaf_moveents(state->args,
2176 						drop_leaf, &drophdr, 0,
2177 						save_leaf, &savehdr, 0,
2178 						drophdr.count);
2179 		} else {
2180 			xfs_attr3_leaf_moveents(state->args,
2181 						drop_leaf, &drophdr, 0,
2182 						save_leaf, &savehdr,
2183 						savehdr.count, drophdr.count);
2184 		}
2185 	} else {
2186 		/*
2187 		 * Destination has holes, so we make a temporary copy
2188 		 * of the leaf and add them both to that.
2189 		 */
2190 		struct xfs_attr_leafblock *tmp_leaf;
2191 		struct xfs_attr3_icleaf_hdr tmphdr;
2192 
2193 		tmp_leaf = kmem_zalloc(state->args->geo->blksize, 0);
2194 
2195 		/*
2196 		 * Copy the header into the temp leaf so that all the stuff
2197 		 * not in the incore header is present and gets copied back in
2198 		 * once we've moved all the entries.
2199 		 */
2200 		memcpy(tmp_leaf, save_leaf, xfs_attr3_leaf_hdr_size(save_leaf));
2201 
2202 		memset(&tmphdr, 0, sizeof(tmphdr));
2203 		tmphdr.magic = savehdr.magic;
2204 		tmphdr.forw = savehdr.forw;
2205 		tmphdr.back = savehdr.back;
2206 		tmphdr.firstused = state->args->geo->blksize;
2207 
2208 		/* write the header to the temp buffer to initialise it */
2209 		xfs_attr3_leaf_hdr_to_disk(state->args->geo, tmp_leaf, &tmphdr);
2210 
2211 		if (xfs_attr3_leaf_order(save_blk->bp, &savehdr,
2212 					 drop_blk->bp, &drophdr)) {
2213 			xfs_attr3_leaf_moveents(state->args,
2214 						drop_leaf, &drophdr, 0,
2215 						tmp_leaf, &tmphdr, 0,
2216 						drophdr.count);
2217 			xfs_attr3_leaf_moveents(state->args,
2218 						save_leaf, &savehdr, 0,
2219 						tmp_leaf, &tmphdr, tmphdr.count,
2220 						savehdr.count);
2221 		} else {
2222 			xfs_attr3_leaf_moveents(state->args,
2223 						save_leaf, &savehdr, 0,
2224 						tmp_leaf, &tmphdr, 0,
2225 						savehdr.count);
2226 			xfs_attr3_leaf_moveents(state->args,
2227 						drop_leaf, &drophdr, 0,
2228 						tmp_leaf, &tmphdr, tmphdr.count,
2229 						drophdr.count);
2230 		}
2231 		memcpy(save_leaf, tmp_leaf, state->args->geo->blksize);
2232 		savehdr = tmphdr; /* struct copy */
2233 		kmem_free(tmp_leaf);
2234 	}
2235 
2236 	xfs_attr3_leaf_hdr_to_disk(state->args->geo, save_leaf, &savehdr);
2237 	xfs_trans_log_buf(state->args->trans, save_blk->bp, 0,
2238 					   state->args->geo->blksize - 1);
2239 
2240 	/*
2241 	 * Copy out last hashval in each block for B-tree code.
2242 	 */
2243 	entry = xfs_attr3_leaf_entryp(save_leaf);
2244 	save_blk->hashval = be32_to_cpu(entry[savehdr.count - 1].hashval);
2245 }
2246 
2247 /*========================================================================
2248  * Routines used for finding things in the Btree.
2249  *========================================================================*/
2250 
2251 /*
2252  * Look up a name in a leaf attribute list structure.
2253  * This is the internal routine, it uses the caller's buffer.
2254  *
2255  * Note that duplicate keys are allowed, but only check within the
2256  * current leaf node.  The Btree code must check in adjacent leaf nodes.
2257  *
2258  * Return in args->index the index into the entry[] array of either
2259  * the found entry, or where the entry should have been (insert before
2260  * that entry).
2261  *
2262  * Don't change the args->value unless we find the attribute.
2263  */
2264 int
2265 xfs_attr3_leaf_lookup_int(
2266 	struct xfs_buf		*bp,
2267 	struct xfs_da_args	*args)
2268 {
2269 	struct xfs_attr_leafblock *leaf;
2270 	struct xfs_attr3_icleaf_hdr ichdr;
2271 	struct xfs_attr_leaf_entry *entry;
2272 	struct xfs_attr_leaf_entry *entries;
2273 	struct xfs_attr_leaf_name_local *name_loc;
2274 	struct xfs_attr_leaf_name_remote *name_rmt;
2275 	xfs_dahash_t		hashval;
2276 	int			probe;
2277 	int			span;
2278 
2279 	trace_xfs_attr_leaf_lookup(args);
2280 
2281 	leaf = bp->b_addr;
2282 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
2283 	entries = xfs_attr3_leaf_entryp(leaf);
2284 	if (ichdr.count >= args->geo->blksize / 8)
2285 		return -EFSCORRUPTED;
2286 
2287 	/*
2288 	 * Binary search.  (note: small blocks will skip this loop)
2289 	 */
2290 	hashval = args->hashval;
2291 	probe = span = ichdr.count / 2;
2292 	for (entry = &entries[probe]; span > 4; entry = &entries[probe]) {
2293 		span /= 2;
2294 		if (be32_to_cpu(entry->hashval) < hashval)
2295 			probe += span;
2296 		else if (be32_to_cpu(entry->hashval) > hashval)
2297 			probe -= span;
2298 		else
2299 			break;
2300 	}
2301 	if (!(probe >= 0 && (!ichdr.count || probe < ichdr.count)))
2302 		return -EFSCORRUPTED;
2303 	if (!(span <= 4 || be32_to_cpu(entry->hashval) == hashval))
2304 		return -EFSCORRUPTED;
2305 
2306 	/*
2307 	 * Since we may have duplicate hashval's, find the first matching
2308 	 * hashval in the leaf.
2309 	 */
2310 	while (probe > 0 && be32_to_cpu(entry->hashval) >= hashval) {
2311 		entry--;
2312 		probe--;
2313 	}
2314 	while (probe < ichdr.count &&
2315 	       be32_to_cpu(entry->hashval) < hashval) {
2316 		entry++;
2317 		probe++;
2318 	}
2319 	if (probe == ichdr.count || be32_to_cpu(entry->hashval) != hashval) {
2320 		args->index = probe;
2321 		return -ENOATTR;
2322 	}
2323 
2324 	/*
2325 	 * Duplicate keys may be present, so search all of them for a match.
2326 	 */
2327 	for (; probe < ichdr.count && (be32_to_cpu(entry->hashval) == hashval);
2328 			entry++, probe++) {
2329 /*
2330  * GROT: Add code to remove incomplete entries.
2331  */
2332 		/*
2333 		 * If we are looking for INCOMPLETE entries, show only those.
2334 		 * If we are looking for complete entries, show only those.
2335 		 */
2336 		if ((args->flags & XFS_ATTR_INCOMPLETE) !=
2337 		    (entry->flags & XFS_ATTR_INCOMPLETE)) {
2338 			continue;
2339 		}
2340 		if (entry->flags & XFS_ATTR_LOCAL) {
2341 			name_loc = xfs_attr3_leaf_name_local(leaf, probe);
2342 			if (name_loc->namelen != args->namelen)
2343 				continue;
2344 			if (memcmp(args->name, name_loc->nameval,
2345 							args->namelen) != 0)
2346 				continue;
2347 			if (!xfs_attr_namesp_match(args->flags, entry->flags))
2348 				continue;
2349 			args->index = probe;
2350 			return -EEXIST;
2351 		} else {
2352 			name_rmt = xfs_attr3_leaf_name_remote(leaf, probe);
2353 			if (name_rmt->namelen != args->namelen)
2354 				continue;
2355 			if (memcmp(args->name, name_rmt->name,
2356 							args->namelen) != 0)
2357 				continue;
2358 			if (!xfs_attr_namesp_match(args->flags, entry->flags))
2359 				continue;
2360 			args->index = probe;
2361 			args->rmtvaluelen = be32_to_cpu(name_rmt->valuelen);
2362 			args->rmtblkno = be32_to_cpu(name_rmt->valueblk);
2363 			args->rmtblkcnt = xfs_attr3_rmt_blocks(
2364 							args->dp->i_mount,
2365 							args->rmtvaluelen);
2366 			return -EEXIST;
2367 		}
2368 	}
2369 	args->index = probe;
2370 	return -ENOATTR;
2371 }
2372 
2373 /*
2374  * Get the value associated with an attribute name from a leaf attribute
2375  * list structure.
2376  *
2377  * If ATTR_KERNOVAL is specified, only the length needs to be returned.
2378  * Unlike a lookup, we only return an error if the attribute does not
2379  * exist or we can't retrieve the value.
2380  */
2381 int
2382 xfs_attr3_leaf_getvalue(
2383 	struct xfs_buf		*bp,
2384 	struct xfs_da_args	*args)
2385 {
2386 	struct xfs_attr_leafblock *leaf;
2387 	struct xfs_attr3_icleaf_hdr ichdr;
2388 	struct xfs_attr_leaf_entry *entry;
2389 	struct xfs_attr_leaf_name_local *name_loc;
2390 	struct xfs_attr_leaf_name_remote *name_rmt;
2391 
2392 	leaf = bp->b_addr;
2393 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
2394 	ASSERT(ichdr.count < args->geo->blksize / 8);
2395 	ASSERT(args->index < ichdr.count);
2396 
2397 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
2398 	if (entry->flags & XFS_ATTR_LOCAL) {
2399 		name_loc = xfs_attr3_leaf_name_local(leaf, args->index);
2400 		ASSERT(name_loc->namelen == args->namelen);
2401 		ASSERT(memcmp(args->name, name_loc->nameval, args->namelen) == 0);
2402 		return xfs_attr_copy_value(args,
2403 					&name_loc->nameval[args->namelen],
2404 					be16_to_cpu(name_loc->valuelen));
2405 	}
2406 
2407 	name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
2408 	ASSERT(name_rmt->namelen == args->namelen);
2409 	ASSERT(memcmp(args->name, name_rmt->name, args->namelen) == 0);
2410 	args->rmtvaluelen = be32_to_cpu(name_rmt->valuelen);
2411 	args->rmtblkno = be32_to_cpu(name_rmt->valueblk);
2412 	args->rmtblkcnt = xfs_attr3_rmt_blocks(args->dp->i_mount,
2413 					       args->rmtvaluelen);
2414 	return xfs_attr_copy_value(args, NULL, args->rmtvaluelen);
2415 }
2416 
2417 /*========================================================================
2418  * Utility routines.
2419  *========================================================================*/
2420 
2421 /*
2422  * Move the indicated entries from one leaf to another.
2423  * NOTE: this routine modifies both source and destination leaves.
2424  */
2425 /*ARGSUSED*/
2426 STATIC void
2427 xfs_attr3_leaf_moveents(
2428 	struct xfs_da_args		*args,
2429 	struct xfs_attr_leafblock	*leaf_s,
2430 	struct xfs_attr3_icleaf_hdr	*ichdr_s,
2431 	int				start_s,
2432 	struct xfs_attr_leafblock	*leaf_d,
2433 	struct xfs_attr3_icleaf_hdr	*ichdr_d,
2434 	int				start_d,
2435 	int				count)
2436 {
2437 	struct xfs_attr_leaf_entry	*entry_s;
2438 	struct xfs_attr_leaf_entry	*entry_d;
2439 	int				desti;
2440 	int				tmp;
2441 	int				i;
2442 
2443 	/*
2444 	 * Check for nothing to do.
2445 	 */
2446 	if (count == 0)
2447 		return;
2448 
2449 	/*
2450 	 * Set up environment.
2451 	 */
2452 	ASSERT(ichdr_s->magic == XFS_ATTR_LEAF_MAGIC ||
2453 	       ichdr_s->magic == XFS_ATTR3_LEAF_MAGIC);
2454 	ASSERT(ichdr_s->magic == ichdr_d->magic);
2455 	ASSERT(ichdr_s->count > 0 && ichdr_s->count < args->geo->blksize / 8);
2456 	ASSERT(ichdr_s->firstused >= (ichdr_s->count * sizeof(*entry_s))
2457 					+ xfs_attr3_leaf_hdr_size(leaf_s));
2458 	ASSERT(ichdr_d->count < args->geo->blksize / 8);
2459 	ASSERT(ichdr_d->firstused >= (ichdr_d->count * sizeof(*entry_d))
2460 					+ xfs_attr3_leaf_hdr_size(leaf_d));
2461 
2462 	ASSERT(start_s < ichdr_s->count);
2463 	ASSERT(start_d <= ichdr_d->count);
2464 	ASSERT(count <= ichdr_s->count);
2465 
2466 
2467 	/*
2468 	 * Move the entries in the destination leaf up to make a hole?
2469 	 */
2470 	if (start_d < ichdr_d->count) {
2471 		tmp  = ichdr_d->count - start_d;
2472 		tmp *= sizeof(xfs_attr_leaf_entry_t);
2473 		entry_s = &xfs_attr3_leaf_entryp(leaf_d)[start_d];
2474 		entry_d = &xfs_attr3_leaf_entryp(leaf_d)[start_d + count];
2475 		memmove(entry_d, entry_s, tmp);
2476 	}
2477 
2478 	/*
2479 	 * Copy all entry's in the same (sorted) order,
2480 	 * but allocate attribute info packed and in sequence.
2481 	 */
2482 	entry_s = &xfs_attr3_leaf_entryp(leaf_s)[start_s];
2483 	entry_d = &xfs_attr3_leaf_entryp(leaf_d)[start_d];
2484 	desti = start_d;
2485 	for (i = 0; i < count; entry_s++, entry_d++, desti++, i++) {
2486 		ASSERT(be16_to_cpu(entry_s->nameidx) >= ichdr_s->firstused);
2487 		tmp = xfs_attr_leaf_entsize(leaf_s, start_s + i);
2488 #ifdef GROT
2489 		/*
2490 		 * Code to drop INCOMPLETE entries.  Difficult to use as we
2491 		 * may also need to change the insertion index.  Code turned
2492 		 * off for 6.2, should be revisited later.
2493 		 */
2494 		if (entry_s->flags & XFS_ATTR_INCOMPLETE) { /* skip partials? */
2495 			memset(xfs_attr3_leaf_name(leaf_s, start_s + i), 0, tmp);
2496 			ichdr_s->usedbytes -= tmp;
2497 			ichdr_s->count -= 1;
2498 			entry_d--;	/* to compensate for ++ in loop hdr */
2499 			desti--;
2500 			if ((start_s + i) < offset)
2501 				result++;	/* insertion index adjustment */
2502 		} else {
2503 #endif /* GROT */
2504 			ichdr_d->firstused -= tmp;
2505 			/* both on-disk, don't endian flip twice */
2506 			entry_d->hashval = entry_s->hashval;
2507 			entry_d->nameidx = cpu_to_be16(ichdr_d->firstused);
2508 			entry_d->flags = entry_s->flags;
2509 			ASSERT(be16_to_cpu(entry_d->nameidx) + tmp
2510 							<= args->geo->blksize);
2511 			memmove(xfs_attr3_leaf_name(leaf_d, desti),
2512 				xfs_attr3_leaf_name(leaf_s, start_s + i), tmp);
2513 			ASSERT(be16_to_cpu(entry_s->nameidx) + tmp
2514 							<= args->geo->blksize);
2515 			memset(xfs_attr3_leaf_name(leaf_s, start_s + i), 0, tmp);
2516 			ichdr_s->usedbytes -= tmp;
2517 			ichdr_d->usedbytes += tmp;
2518 			ichdr_s->count -= 1;
2519 			ichdr_d->count += 1;
2520 			tmp = ichdr_d->count * sizeof(xfs_attr_leaf_entry_t)
2521 					+ xfs_attr3_leaf_hdr_size(leaf_d);
2522 			ASSERT(ichdr_d->firstused >= tmp);
2523 #ifdef GROT
2524 		}
2525 #endif /* GROT */
2526 	}
2527 
2528 	/*
2529 	 * Zero out the entries we just copied.
2530 	 */
2531 	if (start_s == ichdr_s->count) {
2532 		tmp = count * sizeof(xfs_attr_leaf_entry_t);
2533 		entry_s = &xfs_attr3_leaf_entryp(leaf_s)[start_s];
2534 		ASSERT(((char *)entry_s + tmp) <=
2535 		       ((char *)leaf_s + args->geo->blksize));
2536 		memset(entry_s, 0, tmp);
2537 	} else {
2538 		/*
2539 		 * Move the remaining entries down to fill the hole,
2540 		 * then zero the entries at the top.
2541 		 */
2542 		tmp  = (ichdr_s->count - count) * sizeof(xfs_attr_leaf_entry_t);
2543 		entry_s = &xfs_attr3_leaf_entryp(leaf_s)[start_s + count];
2544 		entry_d = &xfs_attr3_leaf_entryp(leaf_s)[start_s];
2545 		memmove(entry_d, entry_s, tmp);
2546 
2547 		tmp = count * sizeof(xfs_attr_leaf_entry_t);
2548 		entry_s = &xfs_attr3_leaf_entryp(leaf_s)[ichdr_s->count];
2549 		ASSERT(((char *)entry_s + tmp) <=
2550 		       ((char *)leaf_s + args->geo->blksize));
2551 		memset(entry_s, 0, tmp);
2552 	}
2553 
2554 	/*
2555 	 * Fill in the freemap information
2556 	 */
2557 	ichdr_d->freemap[0].base = xfs_attr3_leaf_hdr_size(leaf_d);
2558 	ichdr_d->freemap[0].base += ichdr_d->count * sizeof(xfs_attr_leaf_entry_t);
2559 	ichdr_d->freemap[0].size = ichdr_d->firstused - ichdr_d->freemap[0].base;
2560 	ichdr_d->freemap[1].base = 0;
2561 	ichdr_d->freemap[2].base = 0;
2562 	ichdr_d->freemap[1].size = 0;
2563 	ichdr_d->freemap[2].size = 0;
2564 	ichdr_s->holes = 1;	/* leaf may not be compact */
2565 }
2566 
2567 /*
2568  * Pick up the last hashvalue from a leaf block.
2569  */
2570 xfs_dahash_t
2571 xfs_attr_leaf_lasthash(
2572 	struct xfs_buf	*bp,
2573 	int		*count)
2574 {
2575 	struct xfs_attr3_icleaf_hdr ichdr;
2576 	struct xfs_attr_leaf_entry *entries;
2577 	struct xfs_mount *mp = bp->b_mount;
2578 
2579 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, bp->b_addr);
2580 	entries = xfs_attr3_leaf_entryp(bp->b_addr);
2581 	if (count)
2582 		*count = ichdr.count;
2583 	if (!ichdr.count)
2584 		return 0;
2585 	return be32_to_cpu(entries[ichdr.count - 1].hashval);
2586 }
2587 
2588 /*
2589  * Calculate the number of bytes used to store the indicated attribute
2590  * (whether local or remote only calculate bytes in this block).
2591  */
2592 STATIC int
2593 xfs_attr_leaf_entsize(xfs_attr_leafblock_t *leaf, int index)
2594 {
2595 	struct xfs_attr_leaf_entry *entries;
2596 	xfs_attr_leaf_name_local_t *name_loc;
2597 	xfs_attr_leaf_name_remote_t *name_rmt;
2598 	int size;
2599 
2600 	entries = xfs_attr3_leaf_entryp(leaf);
2601 	if (entries[index].flags & XFS_ATTR_LOCAL) {
2602 		name_loc = xfs_attr3_leaf_name_local(leaf, index);
2603 		size = xfs_attr_leaf_entsize_local(name_loc->namelen,
2604 						   be16_to_cpu(name_loc->valuelen));
2605 	} else {
2606 		name_rmt = xfs_attr3_leaf_name_remote(leaf, index);
2607 		size = xfs_attr_leaf_entsize_remote(name_rmt->namelen);
2608 	}
2609 	return size;
2610 }
2611 
2612 /*
2613  * Calculate the number of bytes that would be required to store the new
2614  * attribute (whether local or remote only calculate bytes in this block).
2615  * This routine decides as a side effect whether the attribute will be
2616  * a "local" or a "remote" attribute.
2617  */
2618 int
2619 xfs_attr_leaf_newentsize(
2620 	struct xfs_da_args	*args,
2621 	int			*local)
2622 {
2623 	int			size;
2624 
2625 	size = xfs_attr_leaf_entsize_local(args->namelen, args->valuelen);
2626 	if (size < xfs_attr_leaf_entsize_local_max(args->geo->blksize)) {
2627 		if (local)
2628 			*local = 1;
2629 		return size;
2630 	}
2631 	if (local)
2632 		*local = 0;
2633 	return xfs_attr_leaf_entsize_remote(args->namelen);
2634 }
2635 
2636 
2637 /*========================================================================
2638  * Manage the INCOMPLETE flag in a leaf entry
2639  *========================================================================*/
2640 
2641 /*
2642  * Clear the INCOMPLETE flag on an entry in a leaf block.
2643  */
2644 int
2645 xfs_attr3_leaf_clearflag(
2646 	struct xfs_da_args	*args)
2647 {
2648 	struct xfs_attr_leafblock *leaf;
2649 	struct xfs_attr_leaf_entry *entry;
2650 	struct xfs_attr_leaf_name_remote *name_rmt;
2651 	struct xfs_buf		*bp;
2652 	int			error;
2653 #ifdef DEBUG
2654 	struct xfs_attr3_icleaf_hdr ichdr;
2655 	xfs_attr_leaf_name_local_t *name_loc;
2656 	int namelen;
2657 	char *name;
2658 #endif /* DEBUG */
2659 
2660 	trace_xfs_attr_leaf_clearflag(args);
2661 	/*
2662 	 * Set up the operation.
2663 	 */
2664 	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
2665 	if (error)
2666 		return error;
2667 
2668 	leaf = bp->b_addr;
2669 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
2670 	ASSERT(entry->flags & XFS_ATTR_INCOMPLETE);
2671 
2672 #ifdef DEBUG
2673 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
2674 	ASSERT(args->index < ichdr.count);
2675 	ASSERT(args->index >= 0);
2676 
2677 	if (entry->flags & XFS_ATTR_LOCAL) {
2678 		name_loc = xfs_attr3_leaf_name_local(leaf, args->index);
2679 		namelen = name_loc->namelen;
2680 		name = (char *)name_loc->nameval;
2681 	} else {
2682 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
2683 		namelen = name_rmt->namelen;
2684 		name = (char *)name_rmt->name;
2685 	}
2686 	ASSERT(be32_to_cpu(entry->hashval) == args->hashval);
2687 	ASSERT(namelen == args->namelen);
2688 	ASSERT(memcmp(name, args->name, namelen) == 0);
2689 #endif /* DEBUG */
2690 
2691 	entry->flags &= ~XFS_ATTR_INCOMPLETE;
2692 	xfs_trans_log_buf(args->trans, bp,
2693 			 XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
2694 
2695 	if (args->rmtblkno) {
2696 		ASSERT((entry->flags & XFS_ATTR_LOCAL) == 0);
2697 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
2698 		name_rmt->valueblk = cpu_to_be32(args->rmtblkno);
2699 		name_rmt->valuelen = cpu_to_be32(args->rmtvaluelen);
2700 		xfs_trans_log_buf(args->trans, bp,
2701 			 XFS_DA_LOGRANGE(leaf, name_rmt, sizeof(*name_rmt)));
2702 	}
2703 
2704 	/*
2705 	 * Commit the flag value change and start the next trans in series.
2706 	 */
2707 	return xfs_trans_roll_inode(&args->trans, args->dp);
2708 }
2709 
2710 /*
2711  * Set the INCOMPLETE flag on an entry in a leaf block.
2712  */
2713 int
2714 xfs_attr3_leaf_setflag(
2715 	struct xfs_da_args	*args)
2716 {
2717 	struct xfs_attr_leafblock *leaf;
2718 	struct xfs_attr_leaf_entry *entry;
2719 	struct xfs_attr_leaf_name_remote *name_rmt;
2720 	struct xfs_buf		*bp;
2721 	int error;
2722 #ifdef DEBUG
2723 	struct xfs_attr3_icleaf_hdr ichdr;
2724 #endif
2725 
2726 	trace_xfs_attr_leaf_setflag(args);
2727 
2728 	/*
2729 	 * Set up the operation.
2730 	 */
2731 	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
2732 	if (error)
2733 		return error;
2734 
2735 	leaf = bp->b_addr;
2736 #ifdef DEBUG
2737 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
2738 	ASSERT(args->index < ichdr.count);
2739 	ASSERT(args->index >= 0);
2740 #endif
2741 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
2742 
2743 	ASSERT((entry->flags & XFS_ATTR_INCOMPLETE) == 0);
2744 	entry->flags |= XFS_ATTR_INCOMPLETE;
2745 	xfs_trans_log_buf(args->trans, bp,
2746 			XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
2747 	if ((entry->flags & XFS_ATTR_LOCAL) == 0) {
2748 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
2749 		name_rmt->valueblk = 0;
2750 		name_rmt->valuelen = 0;
2751 		xfs_trans_log_buf(args->trans, bp,
2752 			 XFS_DA_LOGRANGE(leaf, name_rmt, sizeof(*name_rmt)));
2753 	}
2754 
2755 	/*
2756 	 * Commit the flag value change and start the next trans in series.
2757 	 */
2758 	return xfs_trans_roll_inode(&args->trans, args->dp);
2759 }
2760 
2761 /*
2762  * In a single transaction, clear the INCOMPLETE flag on the leaf entry
2763  * given by args->blkno/index and set the INCOMPLETE flag on the leaf
2764  * entry given by args->blkno2/index2.
2765  *
2766  * Note that they could be in different blocks, or in the same block.
2767  */
2768 int
2769 xfs_attr3_leaf_flipflags(
2770 	struct xfs_da_args	*args)
2771 {
2772 	struct xfs_attr_leafblock *leaf1;
2773 	struct xfs_attr_leafblock *leaf2;
2774 	struct xfs_attr_leaf_entry *entry1;
2775 	struct xfs_attr_leaf_entry *entry2;
2776 	struct xfs_attr_leaf_name_remote *name_rmt;
2777 	struct xfs_buf		*bp1;
2778 	struct xfs_buf		*bp2;
2779 	int error;
2780 #ifdef DEBUG
2781 	struct xfs_attr3_icleaf_hdr ichdr1;
2782 	struct xfs_attr3_icleaf_hdr ichdr2;
2783 	xfs_attr_leaf_name_local_t *name_loc;
2784 	int namelen1, namelen2;
2785 	char *name1, *name2;
2786 #endif /* DEBUG */
2787 
2788 	trace_xfs_attr_leaf_flipflags(args);
2789 
2790 	/*
2791 	 * Read the block containing the "old" attr
2792 	 */
2793 	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp1);
2794 	if (error)
2795 		return error;
2796 
2797 	/*
2798 	 * Read the block containing the "new" attr, if it is different
2799 	 */
2800 	if (args->blkno2 != args->blkno) {
2801 		error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno2,
2802 					   -1, &bp2);
2803 		if (error)
2804 			return error;
2805 	} else {
2806 		bp2 = bp1;
2807 	}
2808 
2809 	leaf1 = bp1->b_addr;
2810 	entry1 = &xfs_attr3_leaf_entryp(leaf1)[args->index];
2811 
2812 	leaf2 = bp2->b_addr;
2813 	entry2 = &xfs_attr3_leaf_entryp(leaf2)[args->index2];
2814 
2815 #ifdef DEBUG
2816 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr1, leaf1);
2817 	ASSERT(args->index < ichdr1.count);
2818 	ASSERT(args->index >= 0);
2819 
2820 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr2, leaf2);
2821 	ASSERT(args->index2 < ichdr2.count);
2822 	ASSERT(args->index2 >= 0);
2823 
2824 	if (entry1->flags & XFS_ATTR_LOCAL) {
2825 		name_loc = xfs_attr3_leaf_name_local(leaf1, args->index);
2826 		namelen1 = name_loc->namelen;
2827 		name1 = (char *)name_loc->nameval;
2828 	} else {
2829 		name_rmt = xfs_attr3_leaf_name_remote(leaf1, args->index);
2830 		namelen1 = name_rmt->namelen;
2831 		name1 = (char *)name_rmt->name;
2832 	}
2833 	if (entry2->flags & XFS_ATTR_LOCAL) {
2834 		name_loc = xfs_attr3_leaf_name_local(leaf2, args->index2);
2835 		namelen2 = name_loc->namelen;
2836 		name2 = (char *)name_loc->nameval;
2837 	} else {
2838 		name_rmt = xfs_attr3_leaf_name_remote(leaf2, args->index2);
2839 		namelen2 = name_rmt->namelen;
2840 		name2 = (char *)name_rmt->name;
2841 	}
2842 	ASSERT(be32_to_cpu(entry1->hashval) == be32_to_cpu(entry2->hashval));
2843 	ASSERT(namelen1 == namelen2);
2844 	ASSERT(memcmp(name1, name2, namelen1) == 0);
2845 #endif /* DEBUG */
2846 
2847 	ASSERT(entry1->flags & XFS_ATTR_INCOMPLETE);
2848 	ASSERT((entry2->flags & XFS_ATTR_INCOMPLETE) == 0);
2849 
2850 	entry1->flags &= ~XFS_ATTR_INCOMPLETE;
2851 	xfs_trans_log_buf(args->trans, bp1,
2852 			  XFS_DA_LOGRANGE(leaf1, entry1, sizeof(*entry1)));
2853 	if (args->rmtblkno) {
2854 		ASSERT((entry1->flags & XFS_ATTR_LOCAL) == 0);
2855 		name_rmt = xfs_attr3_leaf_name_remote(leaf1, args->index);
2856 		name_rmt->valueblk = cpu_to_be32(args->rmtblkno);
2857 		name_rmt->valuelen = cpu_to_be32(args->rmtvaluelen);
2858 		xfs_trans_log_buf(args->trans, bp1,
2859 			 XFS_DA_LOGRANGE(leaf1, name_rmt, sizeof(*name_rmt)));
2860 	}
2861 
2862 	entry2->flags |= XFS_ATTR_INCOMPLETE;
2863 	xfs_trans_log_buf(args->trans, bp2,
2864 			  XFS_DA_LOGRANGE(leaf2, entry2, sizeof(*entry2)));
2865 	if ((entry2->flags & XFS_ATTR_LOCAL) == 0) {
2866 		name_rmt = xfs_attr3_leaf_name_remote(leaf2, args->index2);
2867 		name_rmt->valueblk = 0;
2868 		name_rmt->valuelen = 0;
2869 		xfs_trans_log_buf(args->trans, bp2,
2870 			 XFS_DA_LOGRANGE(leaf2, name_rmt, sizeof(*name_rmt)));
2871 	}
2872 
2873 	/*
2874 	 * Commit the flag value change and start the next trans in series.
2875 	 */
2876 	error = xfs_trans_roll_inode(&args->trans, args->dp);
2877 
2878 	return error;
2879 }
2880