1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
4 * Copyright (c) 2013 Red Hat, Inc.
5 * All Rights Reserved.
6 */
7 #ifndef __XFS_DA_FORMAT_H__
8 #define __XFS_DA_FORMAT_H__
9
10 /*
11 * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
12 *
13 * It is used to manage a doubly linked list of all blocks at the same
14 * level in the Btree, and to identify which type of block this is.
15 */
16 #define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
17 #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
18 #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
19 #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
20
21 typedef struct xfs_da_blkinfo {
22 __be32 forw; /* previous block in list */
23 __be32 back; /* following block in list */
24 __be16 magic; /* validity check on block */
25 __be16 pad; /* unused */
26 } xfs_da_blkinfo_t;
27
28 /*
29 * CRC enabled directory structure types
30 *
31 * The headers change size for the additional verification information, but
32 * otherwise the tree layouts and contents are unchanged. Hence the da btree
33 * code can use the struct xfs_da_blkinfo for manipulating the tree links and
34 * magic numbers without modification for both v2 and v3 nodes.
35 */
36 #define XFS_DA3_NODE_MAGIC 0x3ebe /* magic number: non-leaf blocks */
37 #define XFS_ATTR3_LEAF_MAGIC 0x3bee /* magic number: attribute leaf blks */
38 #define XFS_DIR3_LEAF1_MAGIC 0x3df1 /* magic number: v3 dirlf single blks */
39 #define XFS_DIR3_LEAFN_MAGIC 0x3dff /* magic number: v3 dirlf multi blks */
40
41 struct xfs_da3_blkinfo {
42 /*
43 * the node link manipulation code relies on the fact that the first
44 * element of this structure is the struct xfs_da_blkinfo so it can
45 * ignore the differences in the rest of the structures.
46 */
47 struct xfs_da_blkinfo hdr;
48 __be32 crc; /* CRC of block */
49 __be64 blkno; /* first block of the buffer */
50 __be64 lsn; /* sequence number of last write */
51 uuid_t uuid; /* filesystem we belong to */
52 __be64 owner; /* inode that owns the block */
53 };
54
55 /*
56 * This is the structure of the root and intermediate nodes in the Btree.
57 * The leaf nodes are defined above.
58 *
59 * Entries are not packed.
60 *
61 * Since we have duplicate keys, use a binary search but always follow
62 * all match in the block, not just the first match found.
63 */
64 #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
65
66 typedef struct xfs_da_node_hdr {
67 struct xfs_da_blkinfo info; /* block type, links, etc. */
68 __be16 __count; /* count of active entries */
69 __be16 __level; /* level above leaves (leaf == 0) */
70 } xfs_da_node_hdr_t;
71
72 struct xfs_da3_node_hdr {
73 struct xfs_da3_blkinfo info; /* block type, links, etc. */
74 __be16 __count; /* count of active entries */
75 __be16 __level; /* level above leaves (leaf == 0) */
76 __be32 __pad32;
77 };
78
79 #define XFS_DA3_NODE_CRC_OFF (offsetof(struct xfs_da3_node_hdr, info.crc))
80
81 typedef struct xfs_da_node_entry {
82 __be32 hashval; /* hash value for this descendant */
83 __be32 before; /* Btree block before this key */
84 } xfs_da_node_entry_t;
85
86 typedef struct xfs_da_intnode {
87 struct xfs_da_node_hdr hdr;
88 struct xfs_da_node_entry __btree[];
89 } xfs_da_intnode_t;
90
91 struct xfs_da3_intnode {
92 struct xfs_da3_node_hdr hdr;
93 struct xfs_da_node_entry __btree[];
94 };
95
96 /*
97 * Directory version 2.
98 *
99 * There are 4 possible formats:
100 * - shortform - embedded into the inode
101 * - single block - data with embedded leaf at the end
102 * - multiple data blocks, single leaf+freeindex block
103 * - data blocks, node and leaf blocks (btree), freeindex blocks
104 *
105 * Note: many node blocks structures and constants are shared with the attr
106 * code and defined in xfs_da_btree.h.
107 */
108
109 #define XFS_DIR2_BLOCK_MAGIC 0x58443242 /* XD2B: single block dirs */
110 #define XFS_DIR2_DATA_MAGIC 0x58443244 /* XD2D: multiblock dirs */
111 #define XFS_DIR2_FREE_MAGIC 0x58443246 /* XD2F: free index blocks */
112
113 /*
114 * Directory Version 3 With CRCs.
115 *
116 * The tree formats are the same as for version 2 directories. The difference
117 * is in the block header and dirent formats. In many cases the v3 structures
118 * use v2 definitions as they are no different and this makes code sharing much
119 * easier.
120 *
121 * Also, the xfs_dir3_*() functions handle both v2 and v3 formats - if the
122 * format is v2 then they switch to the existing v2 code, or the format is v3
123 * they implement the v3 functionality. This means the existing dir2 is a mix of
124 * xfs_dir2/xfs_dir3 calls and functions. The xfs_dir3 functions are called
125 * where there is a difference in the formats, otherwise the code is unchanged.
126 *
127 * Where it is possible, the code decides what to do based on the magic numbers
128 * in the blocks rather than feature bits in the superblock. This means the code
129 * is as independent of the external XFS code as possible as doesn't require
130 * passing struct xfs_mount pointers into places where it isn't really
131 * necessary.
132 *
133 * Version 3 includes:
134 *
135 * - a larger block header for CRC and identification purposes and so the
136 * offsets of all the structures inside the blocks are different.
137 *
138 * - new magic numbers to be able to detect the v2/v3 types on the fly.
139 */
140
141 #define XFS_DIR3_BLOCK_MAGIC 0x58444233 /* XDB3: single block dirs */
142 #define XFS_DIR3_DATA_MAGIC 0x58444433 /* XDD3: multiblock dirs */
143 #define XFS_DIR3_FREE_MAGIC 0x58444633 /* XDF3: free index blocks */
144
145 /*
146 * Dirents in version 3 directories have a file type field. Additions to this
147 * list are an on-disk format change, requiring feature bits. Valid values
148 * are as follows:
149 */
150 #define XFS_DIR3_FT_UNKNOWN 0
151 #define XFS_DIR3_FT_REG_FILE 1
152 #define XFS_DIR3_FT_DIR 2
153 #define XFS_DIR3_FT_CHRDEV 3
154 #define XFS_DIR3_FT_BLKDEV 4
155 #define XFS_DIR3_FT_FIFO 5
156 #define XFS_DIR3_FT_SOCK 6
157 #define XFS_DIR3_FT_SYMLINK 7
158 #define XFS_DIR3_FT_WHT 8
159
160 #define XFS_DIR3_FT_MAX 9
161
162 /*
163 * Byte offset in data block and shortform entry.
164 */
165 typedef uint16_t xfs_dir2_data_off_t;
166 #define NULLDATAOFF 0xffffU
167 typedef uint xfs_dir2_data_aoff_t; /* argument form */
168
169 /*
170 * Offset in data space of a data entry.
171 */
172 typedef uint32_t xfs_dir2_dataptr_t;
173 #define XFS_DIR2_MAX_DATAPTR ((xfs_dir2_dataptr_t)0xffffffff)
174 #define XFS_DIR2_NULL_DATAPTR ((xfs_dir2_dataptr_t)0)
175
176 /*
177 * Byte offset in a directory.
178 */
179 typedef xfs_off_t xfs_dir2_off_t;
180
181 /*
182 * Directory block number (logical dirblk in file)
183 */
184 typedef uint32_t xfs_dir2_db_t;
185
186 #define XFS_INO32_SIZE 4
187 #define XFS_INO64_SIZE 8
188 #define XFS_INO64_DIFF (XFS_INO64_SIZE - XFS_INO32_SIZE)
189
190 #define XFS_DIR2_MAX_SHORT_INUM ((xfs_ino_t)0xffffffffULL)
191
192 /*
193 * Directory layout when stored internal to an inode.
194 *
195 * Small directories are packed as tightly as possible so as to fit into the
196 * literal area of the inode. These "shortform" directories consist of a
197 * single xfs_dir2_sf_hdr header followed by zero or more xfs_dir2_sf_entry
198 * structures. Due the different inode number storage size and the variable
199 * length name field in the xfs_dir2_sf_entry all these structure are
200 * variable length, and the accessors in this file should be used to iterate
201 * over them.
202 */
203 typedef struct xfs_dir2_sf_hdr {
204 uint8_t count; /* count of entries */
205 uint8_t i8count; /* count of 8-byte inode #s */
206 uint8_t parent[8]; /* parent dir inode number */
207 } __packed xfs_dir2_sf_hdr_t;
208
209 typedef struct xfs_dir2_sf_entry {
210 __u8 namelen; /* actual name length */
211 __u8 offset[2]; /* saved offset */
212 __u8 name[]; /* name, variable size */
213 /*
214 * A single byte containing the file type field follows the inode
215 * number for version 3 directory entries.
216 *
217 * A 64-bit or 32-bit inode number follows here, at a variable offset
218 * after the name.
219 */
220 } __packed xfs_dir2_sf_entry_t;
221
xfs_dir2_sf_hdr_size(int i8count)222 static inline int xfs_dir2_sf_hdr_size(int i8count)
223 {
224 return sizeof(struct xfs_dir2_sf_hdr) -
225 (i8count == 0) * XFS_INO64_DIFF;
226 }
227
228 static inline xfs_dir2_data_aoff_t
xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t * sfep)229 xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
230 {
231 return get_unaligned_be16(sfep->offset);
232 }
233
234 static inline void
xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t * sfep,xfs_dir2_data_aoff_t off)235 xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
236 {
237 put_unaligned_be16(off, sfep->offset);
238 }
239
240 static inline struct xfs_dir2_sf_entry *
xfs_dir2_sf_firstentry(struct xfs_dir2_sf_hdr * hdr)241 xfs_dir2_sf_firstentry(struct xfs_dir2_sf_hdr *hdr)
242 {
243 return (struct xfs_dir2_sf_entry *)
244 ((char *)hdr + xfs_dir2_sf_hdr_size(hdr->i8count));
245 }
246
247 /*
248 * Data block structures.
249 *
250 * A pure data block looks like the following drawing on disk:
251 *
252 * +-------------------------------------------------+
253 * | xfs_dir2_data_hdr_t |
254 * +-------------------------------------------------+
255 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
256 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
257 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
258 * | ... |
259 * +-------------------------------------------------+
260 * | unused space |
261 * +-------------------------------------------------+
262 *
263 * As all the entries are variable size structures the accessors below should
264 * be used to iterate over them.
265 *
266 * In addition to the pure data blocks for the data and node formats,
267 * most structures are also used for the combined data/freespace "block"
268 * format below.
269 */
270
271 #define XFS_DIR2_DATA_ALIGN_LOG 3 /* i.e., 8 bytes */
272 #define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
273 #define XFS_DIR2_DATA_FREE_TAG 0xffff
274 #define XFS_DIR2_DATA_FD_COUNT 3
275
276 /*
277 * Directory address space divided into sections,
278 * spaces separated by 32GB.
279 */
280 #define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
281 #define XFS_DIR2_DATA_SPACE 0
282 #define XFS_DIR2_DATA_OFFSET (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
283
284 /*
285 * Describe a free area in the data block.
286 *
287 * The freespace will be formatted as a xfs_dir2_data_unused_t.
288 */
289 typedef struct xfs_dir2_data_free {
290 __be16 offset; /* start of freespace */
291 __be16 length; /* length of freespace */
292 } xfs_dir2_data_free_t;
293
294 /*
295 * Header for the data blocks.
296 *
297 * The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
298 */
299 typedef struct xfs_dir2_data_hdr {
300 __be32 magic; /* XFS_DIR2_DATA_MAGIC or */
301 /* XFS_DIR2_BLOCK_MAGIC */
302 xfs_dir2_data_free_t bestfree[XFS_DIR2_DATA_FD_COUNT];
303 } xfs_dir2_data_hdr_t;
304
305 /*
306 * define a structure for all the verification fields we are adding to the
307 * directory block structures. This will be used in several structures.
308 * The magic number must be the first entry to align with all the dir2
309 * structures so we determine how to decode them just by the magic number.
310 */
311 struct xfs_dir3_blk_hdr {
312 __be32 magic; /* magic number */
313 __be32 crc; /* CRC of block */
314 __be64 blkno; /* first block of the buffer */
315 __be64 lsn; /* sequence number of last write */
316 uuid_t uuid; /* filesystem we belong to */
317 __be64 owner; /* inode that owns the block */
318 };
319
320 struct xfs_dir3_data_hdr {
321 struct xfs_dir3_blk_hdr hdr;
322 xfs_dir2_data_free_t best_free[XFS_DIR2_DATA_FD_COUNT];
323 __be32 pad; /* 64 bit alignment */
324 };
325
326 #define XFS_DIR3_DATA_CRC_OFF offsetof(struct xfs_dir3_data_hdr, hdr.crc)
327
328 /*
329 * Active entry in a data block.
330 *
331 * Aligned to 8 bytes. After the variable length name field there is a
332 * 2 byte tag field, which can be accessed using xfs_dir3_data_entry_tag_p.
333 *
334 * For dir3 structures, there is file type field between the name and the tag.
335 * This can only be manipulated by helper functions. It is packed hard against
336 * the end of the name so any padding for rounding is between the file type and
337 * the tag.
338 */
339 typedef struct xfs_dir2_data_entry {
340 __be64 inumber; /* inode number */
341 __u8 namelen; /* name length */
342 __u8 name[]; /* name bytes, no null */
343 /* __u8 filetype; */ /* type of inode we point to */
344 /* __be16 tag; */ /* starting offset of us */
345 } xfs_dir2_data_entry_t;
346
347 /*
348 * Unused entry in a data block.
349 *
350 * Aligned to 8 bytes. Tag appears as the last 2 bytes and must be accessed
351 * using xfs_dir2_data_unused_tag_p.
352 */
353 typedef struct xfs_dir2_data_unused {
354 __be16 freetag; /* XFS_DIR2_DATA_FREE_TAG */
355 __be16 length; /* total free length */
356 /* variable offset */
357 __be16 tag; /* starting offset of us */
358 } xfs_dir2_data_unused_t;
359
360 /*
361 * Pointer to a freespace's tag word.
362 */
363 static inline __be16 *
xfs_dir2_data_unused_tag_p(struct xfs_dir2_data_unused * dup)364 xfs_dir2_data_unused_tag_p(struct xfs_dir2_data_unused *dup)
365 {
366 return (__be16 *)((char *)dup +
367 be16_to_cpu(dup->length) - sizeof(__be16));
368 }
369
370 /*
371 * Leaf block structures.
372 *
373 * A pure leaf block looks like the following drawing on disk:
374 *
375 * +---------------------------+
376 * | xfs_dir2_leaf_hdr_t |
377 * +---------------------------+
378 * | xfs_dir2_leaf_entry_t |
379 * | xfs_dir2_leaf_entry_t |
380 * | xfs_dir2_leaf_entry_t |
381 * | xfs_dir2_leaf_entry_t |
382 * | ... |
383 * +---------------------------+
384 * | xfs_dir2_data_off_t |
385 * | xfs_dir2_data_off_t |
386 * | xfs_dir2_data_off_t |
387 * | ... |
388 * +---------------------------+
389 * | xfs_dir2_leaf_tail_t |
390 * +---------------------------+
391 *
392 * The xfs_dir2_data_off_t members (bests) and tail are at the end of the block
393 * for single-leaf (magic = XFS_DIR2_LEAF1_MAGIC) blocks only, but not present
394 * for directories with separate leaf nodes and free space blocks
395 * (magic = XFS_DIR2_LEAFN_MAGIC).
396 *
397 * As all the entries are variable size structures the accessors below should
398 * be used to iterate over them.
399 */
400
401 /*
402 * Offset of the leaf/node space. First block in this space
403 * is the btree root.
404 */
405 #define XFS_DIR2_LEAF_SPACE 1
406 #define XFS_DIR2_LEAF_OFFSET (XFS_DIR2_LEAF_SPACE * XFS_DIR2_SPACE_SIZE)
407
408 /*
409 * Leaf block header.
410 */
411 typedef struct xfs_dir2_leaf_hdr {
412 xfs_da_blkinfo_t info; /* header for da routines */
413 __be16 count; /* count of entries */
414 __be16 stale; /* count of stale entries */
415 } xfs_dir2_leaf_hdr_t;
416
417 struct xfs_dir3_leaf_hdr {
418 struct xfs_da3_blkinfo info; /* header for da routines */
419 __be16 count; /* count of entries */
420 __be16 stale; /* count of stale entries */
421 __be32 pad; /* 64 bit alignment */
422 };
423
424 /*
425 * Leaf block entry.
426 */
427 typedef struct xfs_dir2_leaf_entry {
428 __be32 hashval; /* hash value of name */
429 __be32 address; /* address of data entry */
430 } xfs_dir2_leaf_entry_t;
431
432 /*
433 * Leaf block tail.
434 */
435 typedef struct xfs_dir2_leaf_tail {
436 __be32 bestcount;
437 } xfs_dir2_leaf_tail_t;
438
439 /*
440 * Leaf block.
441 */
442 typedef struct xfs_dir2_leaf {
443 xfs_dir2_leaf_hdr_t hdr; /* leaf header */
444 xfs_dir2_leaf_entry_t __ents[]; /* entries */
445 } xfs_dir2_leaf_t;
446
447 struct xfs_dir3_leaf {
448 struct xfs_dir3_leaf_hdr hdr; /* leaf header */
449 struct xfs_dir2_leaf_entry __ents[]; /* entries */
450 };
451
452 #define XFS_DIR3_LEAF_CRC_OFF offsetof(struct xfs_dir3_leaf_hdr, info.crc)
453
454 /*
455 * Get address of the bests array in the single-leaf block.
456 */
457 static inline __be16 *
xfs_dir2_leaf_bests_p(struct xfs_dir2_leaf_tail * ltp)458 xfs_dir2_leaf_bests_p(struct xfs_dir2_leaf_tail *ltp)
459 {
460 return (__be16 *)ltp - be32_to_cpu(ltp->bestcount);
461 }
462
463 /*
464 * Free space block definitions for the node format.
465 */
466
467 /*
468 * Offset of the freespace index.
469 */
470 #define XFS_DIR2_FREE_SPACE 2
471 #define XFS_DIR2_FREE_OFFSET (XFS_DIR2_FREE_SPACE * XFS_DIR2_SPACE_SIZE)
472
473 typedef struct xfs_dir2_free_hdr {
474 __be32 magic; /* XFS_DIR2_FREE_MAGIC */
475 __be32 firstdb; /* db of first entry */
476 __be32 nvalid; /* count of valid entries */
477 __be32 nused; /* count of used entries */
478 } xfs_dir2_free_hdr_t;
479
480 typedef struct xfs_dir2_free {
481 xfs_dir2_free_hdr_t hdr; /* block header */
482 __be16 bests[]; /* best free counts */
483 /* unused entries are -1 */
484 } xfs_dir2_free_t;
485
486 struct xfs_dir3_free_hdr {
487 struct xfs_dir3_blk_hdr hdr;
488 __be32 firstdb; /* db of first entry */
489 __be32 nvalid; /* count of valid entries */
490 __be32 nused; /* count of used entries */
491 __be32 pad; /* 64 bit alignment */
492 };
493
494 struct xfs_dir3_free {
495 struct xfs_dir3_free_hdr hdr;
496 __be16 bests[]; /* best free counts */
497 /* unused entries are -1 */
498 };
499
500 #define XFS_DIR3_FREE_CRC_OFF offsetof(struct xfs_dir3_free, hdr.hdr.crc)
501
502 /*
503 * Single block format.
504 *
505 * The single block format looks like the following drawing on disk:
506 *
507 * +-------------------------------------------------+
508 * | xfs_dir2_data_hdr_t |
509 * +-------------------------------------------------+
510 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
511 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
512 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t :
513 * | ... |
514 * +-------------------------------------------------+
515 * | unused space |
516 * +-------------------------------------------------+
517 * | ... |
518 * | xfs_dir2_leaf_entry_t |
519 * | xfs_dir2_leaf_entry_t |
520 * +-------------------------------------------------+
521 * | xfs_dir2_block_tail_t |
522 * +-------------------------------------------------+
523 *
524 * As all the entries are variable size structures the accessors below should
525 * be used to iterate over them.
526 */
527
528 typedef struct xfs_dir2_block_tail {
529 __be32 count; /* count of leaf entries */
530 __be32 stale; /* count of stale lf entries */
531 } xfs_dir2_block_tail_t;
532
533 /*
534 * Pointer to the leaf entries embedded in a data block (1-block format)
535 */
536 static inline struct xfs_dir2_leaf_entry *
xfs_dir2_block_leaf_p(struct xfs_dir2_block_tail * btp)537 xfs_dir2_block_leaf_p(struct xfs_dir2_block_tail *btp)
538 {
539 return ((struct xfs_dir2_leaf_entry *)btp) - be32_to_cpu(btp->count);
540 }
541
542
543 /*
544 * Attribute storage layout
545 *
546 * Attribute lists are structured around Btrees where all the data
547 * elements are in the leaf nodes. Attribute names are hashed into an int,
548 * then that int is used as the index into the Btree. Since the hashval
549 * of an attribute name may not be unique, we may have duplicate keys. The
550 * internal links in the Btree are logical block offsets into the file.
551 *
552 * Struct leaf_entry's are packed from the top. Name/values grow from the
553 * bottom but are not packed. The freemap contains run-length-encoded entries
554 * for the free bytes after the leaf_entry's, but only the N largest such,
555 * smaller runs are dropped. When the freemap doesn't show enough space
556 * for an allocation, we compact the name/value area and try again. If we
557 * still don't have enough space, then we have to split the block. The
558 * name/value structs (both local and remote versions) must be 32bit aligned.
559 *
560 * Since we have duplicate hash keys, for each key that matches, compare
561 * the actual name string. The root and intermediate node search always
562 * takes the first-in-the-block key match found, so we should only have
563 * to work "forw"ard. If none matches, continue with the "forw"ard leaf
564 * nodes until the hash key changes or the attribute name is found.
565 *
566 * We store the fact that an attribute is a ROOT/USER/SECURE attribute in
567 * the leaf_entry. The namespaces are independent only because we also look
568 * at the namespace bit when we are looking for a matching attribute name.
569 *
570 * We also store an "incomplete" bit in the leaf_entry. It shows that an
571 * attribute is in the middle of being created and should not be shown to
572 * the user if we crash during the time that the bit is set. We clear the
573 * bit when we have finished setting up the attribute. We do this because
574 * we cannot create some large attributes inside a single transaction, and we
575 * need some indication that we weren't finished if we crash in the middle.
576 */
577 #define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */
578
579 /*
580 * Entries are packed toward the top as tight as possible.
581 */
582 struct xfs_attr_shortform {
583 struct xfs_attr_sf_hdr { /* constant-structure header block */
584 __be16 totsize; /* total bytes in shortform list */
585 __u8 count; /* count of active entries */
586 __u8 padding;
587 } hdr;
588 struct xfs_attr_sf_entry {
589 uint8_t namelen; /* actual length of name (no NULL) */
590 uint8_t valuelen; /* actual length of value (no NULL) */
591 uint8_t flags; /* flags bits (see xfs_attr_leaf.h) */
592 uint8_t nameval[]; /* name & value bytes concatenated */
593 } list[1]; /* variable sized array */
594 };
595
596 typedef struct xfs_attr_leaf_map { /* RLE map of free bytes */
597 __be16 base; /* base of free region */
598 __be16 size; /* length of free region */
599 } xfs_attr_leaf_map_t;
600
601 typedef struct xfs_attr_leaf_hdr { /* constant-structure header block */
602 xfs_da_blkinfo_t info; /* block type, links, etc. */
603 __be16 count; /* count of active leaf_entry's */
604 __be16 usedbytes; /* num bytes of names/values stored */
605 __be16 firstused; /* first used byte in name area */
606 __u8 holes; /* != 0 if blk needs compaction */
607 __u8 pad1;
608 xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE];
609 /* N largest free regions */
610 } xfs_attr_leaf_hdr_t;
611
612 typedef struct xfs_attr_leaf_entry { /* sorted on key, not name */
613 __be32 hashval; /* hash value of name */
614 __be16 nameidx; /* index into buffer of name/value */
615 __u8 flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
616 __u8 pad2; /* unused pad byte */
617 } xfs_attr_leaf_entry_t;
618
619 typedef struct xfs_attr_leaf_name_local {
620 __be16 valuelen; /* number of bytes in value */
621 __u8 namelen; /* length of name bytes */
622 __u8 nameval[1]; /* name/value bytes */
623 } xfs_attr_leaf_name_local_t;
624
625 typedef struct xfs_attr_leaf_name_remote {
626 __be32 valueblk; /* block number of value bytes */
627 __be32 valuelen; /* number of bytes in value */
628 __u8 namelen; /* length of name bytes */
629 __u8 name[1]; /* name bytes */
630 } xfs_attr_leaf_name_remote_t;
631
632 typedef struct xfs_attr_leafblock {
633 xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */
634 xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */
635 /*
636 * The rest of the block contains the following structures after the
637 * leaf entries, growing from the bottom up. The variables are never
638 * referenced and definining them can actually make gcc optimize away
639 * accesses to the 'entries' array above index 0 so don't do that.
640 *
641 * xfs_attr_leaf_name_local_t namelist;
642 * xfs_attr_leaf_name_remote_t valuelist;
643 */
644 } xfs_attr_leafblock_t;
645
646 /*
647 * CRC enabled leaf structures. Called "version 3" structures to match the
648 * version number of the directory and dablk structures for this feature, and
649 * attr2 is already taken by the variable inode attribute fork size feature.
650 */
651 struct xfs_attr3_leaf_hdr {
652 struct xfs_da3_blkinfo info;
653 __be16 count;
654 __be16 usedbytes;
655 __be16 firstused;
656 __u8 holes;
657 __u8 pad1;
658 struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE];
659 __be32 pad2; /* 64 bit alignment */
660 };
661
662 #define XFS_ATTR3_LEAF_CRC_OFF (offsetof(struct xfs_attr3_leaf_hdr, info.crc))
663
664 struct xfs_attr3_leafblock {
665 struct xfs_attr3_leaf_hdr hdr;
666 struct xfs_attr_leaf_entry entries[1];
667
668 /*
669 * The rest of the block contains the following structures after the
670 * leaf entries, growing from the bottom up. The variables are never
671 * referenced, the locations accessed purely from helper functions.
672 *
673 * struct xfs_attr_leaf_name_local
674 * struct xfs_attr_leaf_name_remote
675 */
676 };
677
678 /*
679 * Special value to represent fs block size in the leaf header firstused field.
680 * Only used when block size overflows the 2-bytes available on disk.
681 */
682 #define XFS_ATTR3_LEAF_NULLOFF 0
683
684 /*
685 * Flags used in the leaf_entry[i].flags field.
686 */
687 #define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */
688 #define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */
689 #define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */
690 #define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
691 #define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT)
692 #define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
693 #define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
694 #define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
695 #define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE)
696
697 /*
698 * Alignment for namelist and valuelist entries (since they are mixed
699 * there can be only one alignment value)
700 */
701 #define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t))
702
703 static inline int
xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock * leafp)704 xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp)
705 {
706 if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
707 return sizeof(struct xfs_attr3_leaf_hdr);
708 return sizeof(struct xfs_attr_leaf_hdr);
709 }
710
711 static inline struct xfs_attr_leaf_entry *
xfs_attr3_leaf_entryp(xfs_attr_leafblock_t * leafp)712 xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp)
713 {
714 if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
715 return &((struct xfs_attr3_leafblock *)leafp)->entries[0];
716 return &leafp->entries[0];
717 }
718
719 /*
720 * Cast typed pointers for "local" and "remote" name/value structs.
721 */
722 static inline char *
xfs_attr3_leaf_name(xfs_attr_leafblock_t * leafp,int idx)723 xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
724 {
725 struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp);
726
727 return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)];
728 }
729
730 static inline xfs_attr_leaf_name_remote_t *
xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t * leafp,int idx)731 xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
732 {
733 return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx);
734 }
735
736 static inline xfs_attr_leaf_name_local_t *
xfs_attr3_leaf_name_local(xfs_attr_leafblock_t * leafp,int idx)737 xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
738 {
739 return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx);
740 }
741
742 /*
743 * Calculate total bytes used (including trailing pad for alignment) for
744 * a "local" name/value structure, a "remote" name/value structure, and
745 * a pointer which might be either.
746 */
xfs_attr_leaf_entsize_remote(int nlen)747 static inline int xfs_attr_leaf_entsize_remote(int nlen)
748 {
749 return round_up(sizeof(struct xfs_attr_leaf_name_remote) - 1 +
750 nlen, XFS_ATTR_LEAF_NAME_ALIGN);
751 }
752
xfs_attr_leaf_entsize_local(int nlen,int vlen)753 static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
754 {
755 return round_up(sizeof(struct xfs_attr_leaf_name_local) - 1 +
756 nlen + vlen, XFS_ATTR_LEAF_NAME_ALIGN);
757 }
758
xfs_attr_leaf_entsize_local_max(int bsize)759 static inline int xfs_attr_leaf_entsize_local_max(int bsize)
760 {
761 return (((bsize) >> 1) + ((bsize) >> 2));
762 }
763
764
765
766 /*
767 * Remote attribute block format definition
768 *
769 * There is one of these headers per filesystem block in a remote attribute.
770 * This is done to ensure there is a 1:1 mapping between the attribute value
771 * length and the number of blocks needed to store the attribute. This makes the
772 * verification of a buffer a little more complex, but greatly simplifies the
773 * allocation, reading and writing of these attributes as we don't have to guess
774 * the number of blocks needed to store the attribute data.
775 */
776 #define XFS_ATTR3_RMT_MAGIC 0x5841524d /* XARM */
777
778 struct xfs_attr3_rmt_hdr {
779 __be32 rm_magic;
780 __be32 rm_offset;
781 __be32 rm_bytes;
782 __be32 rm_crc;
783 uuid_t rm_uuid;
784 __be64 rm_owner;
785 __be64 rm_blkno;
786 __be64 rm_lsn;
787 };
788
789 #define XFS_ATTR3_RMT_CRC_OFF offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
790
791 #define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize) \
792 ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
793 sizeof(struct xfs_attr3_rmt_hdr) : 0))
794
795 /* Number of bytes in a directory block. */
xfs_dir2_dirblock_bytes(struct xfs_sb * sbp)796 static inline unsigned int xfs_dir2_dirblock_bytes(struct xfs_sb *sbp)
797 {
798 return 1 << (sbp->sb_blocklog + sbp->sb_dirblklog);
799 }
800
801 xfs_failaddr_t xfs_da3_blkinfo_verify(struct xfs_buf *bp,
802 struct xfs_da3_blkinfo *hdr3);
803
804 #endif /* __XFS_DA_FORMAT_H__ */
805