2 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 #ifndef __XFS_DA_FORMAT_H__
20 #define __XFS_DA_FORMAT_H__
22 /*========================================================================
23 * Directory Structure when greater than XFS_LBSIZE(mp) bytes.
24 *========================================================================*/
27 * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
29 * It is used to manage a doubly linked list of all blocks at the same
30 * level in the Btree, and to identify which type of block this is.
32 #define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
33 #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
34 #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
35 #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
37 typedef struct xfs_da_blkinfo {
38 __be32 forw; /* previous block in list */
39 __be32 back; /* following block in list */
40 __be16 magic; /* validity check on block */
41 __be16 pad; /* unused */
45 * CRC enabled directory structure types
47 * The headers change size for the additional verification information, but
48 * otherwise the tree layouts and contents are unchanged. Hence the da btree
49 * code can use the struct xfs_da_blkinfo for manipulating the tree links and
50 * magic numbers without modification for both v2 and v3 nodes.
52 #define XFS_DA3_NODE_MAGIC 0x3ebe /* magic number: non-leaf blocks */
53 #define XFS_ATTR3_LEAF_MAGIC 0x3bee /* magic number: attribute leaf blks */
54 #define XFS_DIR3_LEAF1_MAGIC 0x3df1 /* magic number: v2 dirlf single blks */
55 #define XFS_DIR3_LEAFN_MAGIC 0x3dff /* magic number: v2 dirlf multi blks */
57 struct xfs_da3_blkinfo {
59 * the node link manipulation code relies on the fact that the first
60 * element of this structure is the struct xfs_da_blkinfo so it can
61 * ignore the differences in the rest of the structures.
63 struct xfs_da_blkinfo hdr;
64 __be32 crc; /* CRC of block */
65 __be64 blkno; /* first block of the buffer */
66 __be64 lsn; /* sequence number of last write */
67 uuid_t uuid; /* filesystem we belong to */
68 __be64 owner; /* inode that owns the block */
72 * This is the structure of the root and intermediate nodes in the Btree.
73 * The leaf nodes are defined above.
75 * Entries are not packed.
77 * Since we have duplicate keys, use a binary search but always follow
78 * all match in the block, not just the first match found.
80 #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
82 typedef struct xfs_da_node_hdr {
83 struct xfs_da_blkinfo info; /* block type, links, etc. */
84 __be16 __count; /* count of active entries */
85 __be16 __level; /* level above leaves (leaf == 0) */
88 struct xfs_da3_node_hdr {
89 struct xfs_da3_blkinfo info; /* block type, links, etc. */
90 __be16 __count; /* count of active entries */
91 __be16 __level; /* level above leaves (leaf == 0) */
95 #define XFS_DA3_NODE_CRC_OFF (offsetof(struct xfs_da3_node_hdr, info.crc))
97 typedef struct xfs_da_node_entry {
98 __be32 hashval; /* hash value for this descendant */
99 __be32 before; /* Btree block before this key */
100 } xfs_da_node_entry_t;
102 typedef struct xfs_da_intnode {
103 struct xfs_da_node_hdr hdr;
104 struct xfs_da_node_entry __btree[];
107 struct xfs_da3_intnode {
108 struct xfs_da3_node_hdr hdr;
109 struct xfs_da_node_entry __btree[];
113 * In-core version of the node header to abstract the differences in the v2 and
114 * v3 disk format of the headers. Callers need to convert to/from disk format as
117 struct xfs_da3_icnode_hdr {
125 #define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize
128 * Directory version 2.
130 * There are 4 possible formats:
131 * - shortform - embedded into the inode
132 * - single block - data with embedded leaf at the end
133 * - multiple data blocks, single leaf+freeindex block
134 * - data blocks, node and leaf blocks (btree), freeindex blocks
136 * Note: many node blocks structures and constants are shared with the attr
137 * code and defined in xfs_da_btree.h.
140 #define XFS_DIR2_BLOCK_MAGIC 0x58443242 /* XD2B: single block dirs */
141 #define XFS_DIR2_DATA_MAGIC 0x58443244 /* XD2D: multiblock dirs */
142 #define XFS_DIR2_FREE_MAGIC 0x58443246 /* XD2F: free index blocks */
145 * Directory Version 3 With CRCs.
147 * The tree formats are the same as for version 2 directories. The difference
148 * is in the block header and dirent formats. In many cases the v3 structures
149 * use v2 definitions as they are no different and this makes code sharing much
152 * Also, the xfs_dir3_*() functions handle both v2 and v3 formats - if the
153 * format is v2 then they switch to the existing v2 code, or the format is v3
154 * they implement the v3 functionality. This means the existing dir2 is a mix of
155 * xfs_dir2/xfs_dir3 calls and functions. The xfs_dir3 functions are called
156 * where there is a difference in the formats, otherwise the code is unchanged.
158 * Where it is possible, the code decides what to do based on the magic numbers
159 * in the blocks rather than feature bits in the superblock. This means the code
160 * is as independent of the external XFS code as possible as doesn't require
161 * passing struct xfs_mount pointers into places where it isn't really
164 * Version 3 includes:
166 * - a larger block header for CRC and identification purposes and so the
167 * offsets of all the structures inside the blocks are different.
169 * - new magic numbers to be able to detect the v2/v3 types on the fly.
172 #define XFS_DIR3_BLOCK_MAGIC 0x58444233 /* XDB3: single block dirs */
173 #define XFS_DIR3_DATA_MAGIC 0x58444433 /* XDD3: multiblock dirs */
174 #define XFS_DIR3_FREE_MAGIC 0x58444633 /* XDF3: free index blocks */
177 * Dirents in version 3 directories have a file type field. Additions to this
178 * list are an on-disk format change, requiring feature bits. Valid values
181 #define XFS_DIR3_FT_UNKNOWN 0
182 #define XFS_DIR3_FT_REG_FILE 1
183 #define XFS_DIR3_FT_DIR 2
184 #define XFS_DIR3_FT_CHRDEV 3
185 #define XFS_DIR3_FT_BLKDEV 4
186 #define XFS_DIR3_FT_FIFO 5
187 #define XFS_DIR3_FT_SOCK 6
188 #define XFS_DIR3_FT_SYMLINK 7
189 #define XFS_DIR3_FT_WHT 8
191 #define XFS_DIR3_FT_MAX 9
194 * Byte offset in data block and shortform entry.
196 typedef __uint16_t xfs_dir2_data_off_t;
197 #define NULLDATAOFF 0xffffU
198 typedef uint xfs_dir2_data_aoff_t; /* argument form */
201 * Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
202 * Only need 16 bits, this is the byte offset into the single block form.
204 typedef struct { __uint8_t i[2]; } __arch_pack xfs_dir2_sf_off_t;
207 * Offset in data space of a data entry.
209 typedef __uint32_t xfs_dir2_dataptr_t;
210 #define XFS_DIR2_MAX_DATAPTR ((xfs_dir2_dataptr_t)0xffffffff)
211 #define XFS_DIR2_NULL_DATAPTR ((xfs_dir2_dataptr_t)0)
214 * Byte offset in a directory.
216 typedef xfs_off_t xfs_dir2_off_t;
219 * Directory block number (logical dirblk in file)
221 typedef __uint32_t xfs_dir2_db_t;
224 * Inode number stored as 8 8-bit values.
226 typedef struct { __uint8_t i[8]; } xfs_dir2_ino8_t;
229 * Inode number stored as 4 8-bit values.
230 * Works a lot of the time, when all the inode numbers in a directory
233 typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;
239 #define XFS_DIR2_MAX_SHORT_INUM ((xfs_ino_t)0xffffffffULL)
242 * Directory layout when stored internal to an inode.
244 * Small directories are packed as tightly as possible so as to fit into the
245 * literal area of the inode. These "shortform" directories consist of a
246 * single xfs_dir2_sf_hdr header followed by zero or more xfs_dir2_sf_entry
247 * structures. Due the different inode number storage size and the variable
248 * length name field in the xfs_dir2_sf_entry all these structure are
249 * variable length, and the accessors in this file should be used to iterate
252 typedef struct xfs_dir2_sf_hdr {
253 __uint8_t count; /* count of entries */
254 __uint8_t i8count; /* count of 8-byte inode #s */
255 xfs_dir2_inou_t parent; /* parent dir inode number */
256 } __arch_pack xfs_dir2_sf_hdr_t;
258 typedef struct xfs_dir2_sf_entry {
259 __u8 namelen; /* actual name length */
260 xfs_dir2_sf_off_t offset; /* saved offset */
261 __u8 name[]; /* name, variable size */
263 * A single byte containing the file type field follows the inode
264 * number for version 3 directory entries.
266 * A xfs_dir2_ino8_t or xfs_dir2_ino4_t follows here, at a
267 * variable offset after the name.
269 } __arch_pack xfs_dir2_sf_entry_t;
271 static inline int xfs_dir2_sf_hdr_size(int i8count)
273 return sizeof(struct xfs_dir2_sf_hdr) -
275 (sizeof(xfs_dir2_ino8_t) - sizeof(xfs_dir2_ino4_t));
278 static inline xfs_dir2_data_aoff_t
279 xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
281 return get_unaligned_be16(&sfep->offset.i);
285 xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
287 put_unaligned_be16(off, &sfep->offset.i);
290 static inline struct xfs_dir2_sf_entry *
291 xfs_dir2_sf_firstentry(struct xfs_dir2_sf_hdr *hdr)
293 return (struct xfs_dir2_sf_entry *)
294 ((char *)hdr + xfs_dir2_sf_hdr_size(hdr->i8count));
298 * Data block structures.
300 * A pure data block looks like the following drawing on disk:
302 * +-------------------------------------------------+
303 * | xfs_dir2_data_hdr_t |
304 * +-------------------------------------------------+
305 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
306 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
307 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
309 * +-------------------------------------------------+
311 * +-------------------------------------------------+
313 * As all the entries are variable size structures the accessors below should
314 * be used to iterate over them.
316 * In addition to the pure data blocks for the data and node formats,
317 * most structures are also used for the combined data/freespace "block"
321 #define XFS_DIR2_DATA_ALIGN_LOG 3 /* i.e., 8 bytes */
322 #define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
323 #define XFS_DIR2_DATA_FREE_TAG 0xffff
324 #define XFS_DIR2_DATA_FD_COUNT 3
327 * Directory address space divided into sections,
328 * spaces separated by 32GB.
330 #define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
331 #define XFS_DIR2_DATA_SPACE 0
332 #define XFS_DIR2_DATA_OFFSET (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
333 #define XFS_DIR2_DATA_FIRSTDB(mp) \
334 xfs_dir2_byte_to_db(mp, XFS_DIR2_DATA_OFFSET)
337 * Describe a free area in the data block.
339 * The freespace will be formatted as a xfs_dir2_data_unused_t.
341 typedef struct xfs_dir2_data_free {
342 __be16 offset; /* start of freespace */
343 __be16 length; /* length of freespace */
344 } xfs_dir2_data_free_t;
347 * Header for the data blocks.
349 * The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
351 typedef struct xfs_dir2_data_hdr {
352 __be32 magic; /* XFS_DIR2_DATA_MAGIC or */
353 /* XFS_DIR2_BLOCK_MAGIC */
354 xfs_dir2_data_free_t bestfree[XFS_DIR2_DATA_FD_COUNT];
355 } xfs_dir2_data_hdr_t;
358 * define a structure for all the verification fields we are adding to the
359 * directory block structures. This will be used in several structures.
360 * The magic number must be the first entry to align with all the dir2
361 * structures so we determine how to decode them just by the magic number.
363 struct xfs_dir3_blk_hdr {
364 __be32 magic; /* magic number */
365 __be32 crc; /* CRC of block */
366 __be64 blkno; /* first block of the buffer */
367 __be64 lsn; /* sequence number of last write */
368 uuid_t uuid; /* filesystem we belong to */
369 __be64 owner; /* inode that owns the block */
372 struct xfs_dir3_data_hdr {
373 struct xfs_dir3_blk_hdr hdr;
374 xfs_dir2_data_free_t best_free[XFS_DIR2_DATA_FD_COUNT];
375 __be32 pad; /* 64 bit alignment */
378 #define XFS_DIR3_DATA_CRC_OFF offsetof(struct xfs_dir3_data_hdr, hdr.crc)
381 * Active entry in a data block.
383 * Aligned to 8 bytes. After the variable length name field there is a
384 * 2 byte tag field, which can be accessed using xfs_dir3_data_entry_tag_p.
386 * For dir3 structures, there is file type field between the name and the tag.
387 * This can only be manipulated by helper functions. It is packed hard against
388 * the end of the name so any padding for rounding is between the file type and
391 typedef struct xfs_dir2_data_entry {
392 __be64 inumber; /* inode number */
393 __u8 namelen; /* name length */
394 __u8 name[]; /* name bytes, no null */
395 /* __u8 filetype; */ /* type of inode we point to */
396 /* __be16 tag; */ /* starting offset of us */
397 } xfs_dir2_data_entry_t;
400 * Unused entry in a data block.
402 * Aligned to 8 bytes. Tag appears as the last 2 bytes and must be accessed
403 * using xfs_dir2_data_unused_tag_p.
405 typedef struct xfs_dir2_data_unused {
406 __be16 freetag; /* XFS_DIR2_DATA_FREE_TAG */
407 __be16 length; /* total free length */
408 /* variable offset */
409 __be16 tag; /* starting offset of us */
410 } xfs_dir2_data_unused_t;
413 * Pointer to a freespace's tag word.
415 static inline __be16 *
416 xfs_dir2_data_unused_tag_p(struct xfs_dir2_data_unused *dup)
418 return (__be16 *)((char *)dup +
419 be16_to_cpu(dup->length) - sizeof(__be16));
423 * Leaf block structures.
425 * A pure leaf block looks like the following drawing on disk:
427 * +---------------------------+
428 * | xfs_dir2_leaf_hdr_t |
429 * +---------------------------+
430 * | xfs_dir2_leaf_entry_t |
431 * | xfs_dir2_leaf_entry_t |
432 * | xfs_dir2_leaf_entry_t |
433 * | xfs_dir2_leaf_entry_t |
435 * +---------------------------+
436 * | xfs_dir2_data_off_t |
437 * | xfs_dir2_data_off_t |
438 * | xfs_dir2_data_off_t |
440 * +---------------------------+
441 * | xfs_dir2_leaf_tail_t |
442 * +---------------------------+
444 * The xfs_dir2_data_off_t members (bests) and tail are at the end of the block
445 * for single-leaf (magic = XFS_DIR2_LEAF1_MAGIC) blocks only, but not present
446 * for directories with separate leaf nodes and free space blocks
447 * (magic = XFS_DIR2_LEAFN_MAGIC).
449 * As all the entries are variable size structures the accessors below should
450 * be used to iterate over them.
454 * Offset of the leaf/node space. First block in this space
457 #define XFS_DIR2_LEAF_SPACE 1
458 #define XFS_DIR2_LEAF_OFFSET (XFS_DIR2_LEAF_SPACE * XFS_DIR2_SPACE_SIZE)
459 #define XFS_DIR2_LEAF_FIRSTDB(mp) \
460 xfs_dir2_byte_to_db(mp, XFS_DIR2_LEAF_OFFSET)
465 typedef struct xfs_dir2_leaf_hdr {
466 xfs_da_blkinfo_t info; /* header for da routines */
467 __be16 count; /* count of entries */
468 __be16 stale; /* count of stale entries */
469 } xfs_dir2_leaf_hdr_t;
471 struct xfs_dir3_leaf_hdr {
472 struct xfs_da3_blkinfo info; /* header for da routines */
473 __be16 count; /* count of entries */
474 __be16 stale; /* count of stale entries */
475 __be32 pad; /* 64 bit alignment */
478 struct xfs_dir3_icleaf_hdr {
489 typedef struct xfs_dir2_leaf_entry {
490 __be32 hashval; /* hash value of name */
491 __be32 address; /* address of data entry */
492 } xfs_dir2_leaf_entry_t;
497 typedef struct xfs_dir2_leaf_tail {
499 } xfs_dir2_leaf_tail_t;
504 typedef struct xfs_dir2_leaf {
505 xfs_dir2_leaf_hdr_t hdr; /* leaf header */
506 xfs_dir2_leaf_entry_t __ents[]; /* entries */
509 struct xfs_dir3_leaf {
510 struct xfs_dir3_leaf_hdr hdr; /* leaf header */
511 struct xfs_dir2_leaf_entry __ents[]; /* entries */
514 #define XFS_DIR3_LEAF_CRC_OFF offsetof(struct xfs_dir3_leaf_hdr, info.crc)
517 * Get address of the bestcount field in the single-leaf block.
519 static inline struct xfs_dir2_leaf_tail *
520 xfs_dir2_leaf_tail_p(struct xfs_mount *mp, struct xfs_dir2_leaf *lp)
522 return (struct xfs_dir2_leaf_tail *)
523 ((char *)lp + mp->m_dirblksize -
524 sizeof(struct xfs_dir2_leaf_tail));
528 * Get address of the bests array in the single-leaf block.
530 static inline __be16 *
531 xfs_dir2_leaf_bests_p(struct xfs_dir2_leaf_tail *ltp)
533 return (__be16 *)ltp - be32_to_cpu(ltp->bestcount);
537 * DB blocks here are logical directory block numbers, not filesystem blocks.
541 * Convert dataptr to byte in file space
543 static inline xfs_dir2_off_t
544 xfs_dir2_dataptr_to_byte(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
546 return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
550 * Convert byte in file space to dataptr. It had better be aligned.
552 static inline xfs_dir2_dataptr_t
553 xfs_dir2_byte_to_dataptr(struct xfs_mount *mp, xfs_dir2_off_t by)
555 return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
559 * Convert byte in space to (DB) block
561 static inline xfs_dir2_db_t
562 xfs_dir2_byte_to_db(struct xfs_mount *mp, xfs_dir2_off_t by)
564 return (xfs_dir2_db_t)
565 (by >> (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog));
569 * Convert dataptr to a block number
571 static inline xfs_dir2_db_t
572 xfs_dir2_dataptr_to_db(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
574 return xfs_dir2_byte_to_db(mp, xfs_dir2_dataptr_to_byte(mp, dp));
578 * Convert byte in space to offset in a block
580 static inline xfs_dir2_data_aoff_t
581 xfs_dir2_byte_to_off(struct xfs_mount *mp, xfs_dir2_off_t by)
583 return (xfs_dir2_data_aoff_t)(by &
584 ((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) - 1));
588 * Convert dataptr to a byte offset in a block
590 static inline xfs_dir2_data_aoff_t
591 xfs_dir2_dataptr_to_off(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
593 return xfs_dir2_byte_to_off(mp, xfs_dir2_dataptr_to_byte(mp, dp));
597 * Convert block and offset to byte in space
599 static inline xfs_dir2_off_t
600 xfs_dir2_db_off_to_byte(struct xfs_mount *mp, xfs_dir2_db_t db,
601 xfs_dir2_data_aoff_t o)
603 return ((xfs_dir2_off_t)db <<
604 (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) + o;
608 * Convert block (DB) to block (dablk)
610 static inline xfs_dablk_t
611 xfs_dir2_db_to_da(struct xfs_mount *mp, xfs_dir2_db_t db)
613 return (xfs_dablk_t)(db << mp->m_sb.sb_dirblklog);
617 * Convert byte in space to (DA) block
619 static inline xfs_dablk_t
620 xfs_dir2_byte_to_da(struct xfs_mount *mp, xfs_dir2_off_t by)
622 return xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, by));
626 * Convert block and offset to dataptr
628 static inline xfs_dir2_dataptr_t
629 xfs_dir2_db_off_to_dataptr(struct xfs_mount *mp, xfs_dir2_db_t db,
630 xfs_dir2_data_aoff_t o)
632 return xfs_dir2_byte_to_dataptr(mp, xfs_dir2_db_off_to_byte(mp, db, o));
636 * Convert block (dablk) to block (DB)
638 static inline xfs_dir2_db_t
639 xfs_dir2_da_to_db(struct xfs_mount *mp, xfs_dablk_t da)
641 return (xfs_dir2_db_t)(da >> mp->m_sb.sb_dirblklog);
645 * Convert block (dablk) to byte offset in space
647 static inline xfs_dir2_off_t
648 xfs_dir2_da_to_byte(struct xfs_mount *mp, xfs_dablk_t da)
650 return xfs_dir2_db_off_to_byte(mp, xfs_dir2_da_to_db(mp, da), 0);
654 * Free space block defintions for the node format.
658 * Offset of the freespace index.
660 #define XFS_DIR2_FREE_SPACE 2
661 #define XFS_DIR2_FREE_OFFSET (XFS_DIR2_FREE_SPACE * XFS_DIR2_SPACE_SIZE)
662 #define XFS_DIR2_FREE_FIRSTDB(mp) \
663 xfs_dir2_byte_to_db(mp, XFS_DIR2_FREE_OFFSET)
665 typedef struct xfs_dir2_free_hdr {
666 __be32 magic; /* XFS_DIR2_FREE_MAGIC */
667 __be32 firstdb; /* db of first entry */
668 __be32 nvalid; /* count of valid entries */
669 __be32 nused; /* count of used entries */
670 } xfs_dir2_free_hdr_t;
672 typedef struct xfs_dir2_free {
673 xfs_dir2_free_hdr_t hdr; /* block header */
674 __be16 bests[]; /* best free counts */
675 /* unused entries are -1 */
678 struct xfs_dir3_free_hdr {
679 struct xfs_dir3_blk_hdr hdr;
680 __be32 firstdb; /* db of first entry */
681 __be32 nvalid; /* count of valid entries */
682 __be32 nused; /* count of used entries */
683 __be32 pad; /* 64 bit alignment */
686 struct xfs_dir3_free {
687 struct xfs_dir3_free_hdr hdr;
688 __be16 bests[]; /* best free counts */
689 /* unused entries are -1 */
692 #define XFS_DIR3_FREE_CRC_OFF offsetof(struct xfs_dir3_free, hdr.hdr.crc)
695 * In core version of the free block header, abstracted away from on-disk format
696 * differences. Use this in the code, and convert to/from the disk version using
697 * xfs_dir3_free_hdr_from_disk/xfs_dir3_free_hdr_to_disk.
699 struct xfs_dir3_icfree_hdr {
708 xfs_dir3_free_hdr_size(struct xfs_mount *mp)
710 if (xfs_sb_version_hascrc(&mp->m_sb))
711 return sizeof(struct xfs_dir3_free_hdr);
712 return sizeof(struct xfs_dir2_free_hdr);
716 xfs_dir3_free_max_bests(struct xfs_mount *mp)
718 return (mp->m_dirblksize - xfs_dir3_free_hdr_size(mp)) /
719 sizeof(xfs_dir2_data_off_t);
722 static inline __be16 *
723 xfs_dir3_free_bests_p(struct xfs_mount *mp, struct xfs_dir2_free *free)
725 return (__be16 *)((char *)free + xfs_dir3_free_hdr_size(mp));
729 * Convert data space db to the corresponding free db.
731 static inline xfs_dir2_db_t
732 xfs_dir2_db_to_fdb(struct xfs_mount *mp, xfs_dir2_db_t db)
734 return XFS_DIR2_FREE_FIRSTDB(mp) + db / xfs_dir3_free_max_bests(mp);
738 * Convert data space db to the corresponding index in a free db.
741 xfs_dir2_db_to_fdindex(struct xfs_mount *mp, xfs_dir2_db_t db)
743 return db % xfs_dir3_free_max_bests(mp);
747 * Single block format.
749 * The single block format looks like the following drawing on disk:
751 * +-------------------------------------------------+
752 * | xfs_dir2_data_hdr_t |
753 * +-------------------------------------------------+
754 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
755 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
756 * | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t :
758 * +-------------------------------------------------+
760 * +-------------------------------------------------+
762 * | xfs_dir2_leaf_entry_t |
763 * | xfs_dir2_leaf_entry_t |
764 * +-------------------------------------------------+
765 * | xfs_dir2_block_tail_t |
766 * +-------------------------------------------------+
768 * As all the entries are variable size structures the accessors below should
769 * be used to iterate over them.
772 typedef struct xfs_dir2_block_tail {
773 __be32 count; /* count of leaf entries */
774 __be32 stale; /* count of stale lf entries */
775 } xfs_dir2_block_tail_t;
778 * Pointer to the leaf header embedded in a data block (1-block format)
780 static inline struct xfs_dir2_block_tail *
781 xfs_dir2_block_tail_p(struct xfs_mount *mp, struct xfs_dir2_data_hdr *hdr)
783 return ((struct xfs_dir2_block_tail *)
784 ((char *)hdr + mp->m_dirblksize)) - 1;
788 * Pointer to the leaf entries embedded in a data block (1-block format)
790 static inline struct xfs_dir2_leaf_entry *
791 xfs_dir2_block_leaf_p(struct xfs_dir2_block_tail *btp)
793 return ((struct xfs_dir2_leaf_entry *)btp) - be32_to_cpu(btp->count);
798 * Attribute storage layout
800 * Attribute lists are structured around Btrees where all the data
801 * elements are in the leaf nodes. Attribute names are hashed into an int,
802 * then that int is used as the index into the Btree. Since the hashval
803 * of an attribute name may not be unique, we may have duplicate keys. The
804 * internal links in the Btree are logical block offsets into the file.
806 *========================================================================
807 * Attribute structure when equal to XFS_LBSIZE(mp) bytes.
808 *========================================================================
810 * Struct leaf_entry's are packed from the top. Name/values grow from the
811 * bottom but are not packed. The freemap contains run-length-encoded entries
812 * for the free bytes after the leaf_entry's, but only the N largest such,
813 * smaller runs are dropped. When the freemap doesn't show enough space
814 * for an allocation, we compact the name/value area and try again. If we
815 * still don't have enough space, then we have to split the block. The
816 * name/value structs (both local and remote versions) must be 32bit aligned.
818 * Since we have duplicate hash keys, for each key that matches, compare
819 * the actual name string. The root and intermediate node search always
820 * takes the first-in-the-block key match found, so we should only have
821 * to work "forw"ard. If none matches, continue with the "forw"ard leaf
822 * nodes until the hash key changes or the attribute name is found.
824 * We store the fact that an attribute is a ROOT/USER/SECURE attribute in
825 * the leaf_entry. The namespaces are independent only because we also look
826 * at the namespace bit when we are looking for a matching attribute name.
828 * We also store an "incomplete" bit in the leaf_entry. It shows that an
829 * attribute is in the middle of being created and should not be shown to
830 * the user if we crash during the time that the bit is set. We clear the
831 * bit when we have finished setting up the attribute. We do this because
832 * we cannot create some large attributes inside a single transaction, and we
833 * need some indication that we weren't finished if we crash in the middle.
835 #define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */
837 typedef struct xfs_attr_leaf_map { /* RLE map of free bytes */
838 __be16 base; /* base of free region */
839 __be16 size; /* length of free region */
840 } xfs_attr_leaf_map_t;
842 typedef struct xfs_attr_leaf_hdr { /* constant-structure header block */
843 xfs_da_blkinfo_t info; /* block type, links, etc. */
844 __be16 count; /* count of active leaf_entry's */
845 __be16 usedbytes; /* num bytes of names/values stored */
846 __be16 firstused; /* first used byte in name area */
847 __u8 holes; /* != 0 if blk needs compaction */
849 xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE];
850 /* N largest free regions */
851 } xfs_attr_leaf_hdr_t;
853 typedef struct xfs_attr_leaf_entry { /* sorted on key, not name */
854 __be32 hashval; /* hash value of name */
855 __be16 nameidx; /* index into buffer of name/value */
856 __u8 flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
857 __u8 pad2; /* unused pad byte */
858 } xfs_attr_leaf_entry_t;
860 typedef struct xfs_attr_leaf_name_local {
861 __be16 valuelen; /* number of bytes in value */
862 __u8 namelen; /* length of name bytes */
863 __u8 nameval[1]; /* name/value bytes */
864 } xfs_attr_leaf_name_local_t;
866 typedef struct xfs_attr_leaf_name_remote {
867 __be32 valueblk; /* block number of value bytes */
868 __be32 valuelen; /* number of bytes in value */
869 __u8 namelen; /* length of name bytes */
870 __u8 name[1]; /* name bytes */
871 } xfs_attr_leaf_name_remote_t;
873 typedef struct xfs_attr_leafblock {
874 xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */
875 xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */
876 xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */
877 xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */
878 } xfs_attr_leafblock_t;
881 * CRC enabled leaf structures. Called "version 3" structures to match the
882 * version number of the directory and dablk structures for this feature, and
883 * attr2 is already taken by the variable inode attribute fork size feature.
885 struct xfs_attr3_leaf_hdr {
886 struct xfs_da3_blkinfo info;
892 struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE];
893 __be32 pad2; /* 64 bit alignment */
896 #define XFS_ATTR3_LEAF_CRC_OFF (offsetof(struct xfs_attr3_leaf_hdr, info.crc))
898 struct xfs_attr3_leafblock {
899 struct xfs_attr3_leaf_hdr hdr;
900 struct xfs_attr_leaf_entry entries[1];
903 * The rest of the block contains the following structures after the
904 * leaf entries, growing from the bottom up. The variables are never
905 * referenced, the locations accessed purely from helper functions.
907 * struct xfs_attr_leaf_name_local
908 * struct xfs_attr_leaf_name_remote
913 * incore, neutral version of the attribute leaf header
915 struct xfs_attr3_icleaf_hdr {
920 __uint16_t usedbytes;
921 __uint16_t firstused;
926 } freemap[XFS_ATTR_LEAF_MAPSIZE];
930 * Flags used in the leaf_entry[i].flags field.
931 * NOTE: the INCOMPLETE bit must not collide with the flags bits specified
932 * on the system call, they are "or"ed together for various operations.
934 #define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */
935 #define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */
936 #define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */
937 #define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
938 #define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT)
939 #define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
940 #define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
941 #define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
944 * Conversion macros for converting namespace bits from argument flags
947 #define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE)
948 #define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE)
949 #define XFS_ATTR_NSP_ONDISK(flags) ((flags) & XFS_ATTR_NSP_ONDISK_MASK)
950 #define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK)
951 #define XFS_ATTR_NSP_ARGS_TO_ONDISK(x) (((x) & ATTR_ROOT ? XFS_ATTR_ROOT : 0) |\
952 ((x) & ATTR_SECURE ? XFS_ATTR_SECURE : 0))
953 #define XFS_ATTR_NSP_ONDISK_TO_ARGS(x) (((x) & XFS_ATTR_ROOT ? ATTR_ROOT : 0) |\
954 ((x) & XFS_ATTR_SECURE ? ATTR_SECURE : 0))
957 * Alignment for namelist and valuelist entries (since they are mixed
958 * there can be only one alignment value)
960 #define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t))
963 xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp)
965 if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
966 return sizeof(struct xfs_attr3_leaf_hdr);
967 return sizeof(struct xfs_attr_leaf_hdr);
970 static inline struct xfs_attr_leaf_entry *
971 xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp)
973 if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
974 return &((struct xfs_attr3_leafblock *)leafp)->entries[0];
975 return &leafp->entries[0];
979 * Cast typed pointers for "local" and "remote" name/value structs.
982 xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
984 struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp);
986 return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)];
989 static inline xfs_attr_leaf_name_remote_t *
990 xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
992 return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx);
995 static inline xfs_attr_leaf_name_local_t *
996 xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
998 return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx);
1002 * Calculate total bytes used (including trailing pad for alignment) for
1003 * a "local" name/value structure, a "remote" name/value structure, and
1004 * a pointer which might be either.
1006 static inline int xfs_attr_leaf_entsize_remote(int nlen)
1008 return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \
1009 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
1012 static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
1014 return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) +
1015 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
1018 static inline int xfs_attr_leaf_entsize_local_max(int bsize)
1020 return (((bsize) >> 1) + ((bsize) >> 2));
1026 * Remote attribute block format definition
1028 * There is one of these headers per filesystem block in a remote attribute.
1029 * This is done to ensure there is a 1:1 mapping between the attribute value
1030 * length and the number of blocks needed to store the attribute. This makes the
1031 * verification of a buffer a little more complex, but greatly simplifies the
1032 * allocation, reading and writing of these attributes as we don't have to guess
1033 * the number of blocks needed to store the attribute data.
1035 #define XFS_ATTR3_RMT_MAGIC 0x5841524d /* XARM */
1037 struct xfs_attr3_rmt_hdr {
1048 #define XFS_ATTR3_RMT_CRC_OFF offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
1050 #define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize) \
1051 ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
1052 sizeof(struct xfs_attr3_rmt_hdr) : 0))
1054 #endif /* __XFS_DA_FORMAT_H__ */