xref: /linux/fs/xfs/libxfs/xfs_format.h (revision c8b90d40d5bba8e6fba457b8a7c10d3c0d467e37)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #ifndef __XFS_FORMAT_H__
7 #define __XFS_FORMAT_H__
8 
9 /*
10  * XFS On Disk Format Definitions
11  *
12  * This header file defines all the on-disk format definitions for
13  * general XFS objects. Directory and attribute related objects are defined in
14  * xfs_da_format.h, which log and log item formats are defined in
15  * xfs_log_format.h. Everything else goes here.
16  */
17 
18 struct xfs_mount;
19 struct xfs_trans;
20 struct xfs_inode;
21 struct xfs_buf;
22 struct xfs_ifork;
23 
24 /*
25  * Super block
26  * Fits into a sector-sized buffer at address 0 of each allocation group.
27  * Only the first of these is ever updated except during growfs.
28  */
29 #define	XFS_SB_MAGIC		0x58465342	/* 'XFSB' */
30 #define	XFS_SB_VERSION_1	1		/* 5.3, 6.0.1, 6.1 */
31 #define	XFS_SB_VERSION_2	2		/* 6.2 - attributes */
32 #define	XFS_SB_VERSION_3	3		/* 6.2 - new inode version */
33 #define	XFS_SB_VERSION_4	4		/* 6.2+ - bitmask version */
34 #define	XFS_SB_VERSION_5	5		/* CRC enabled filesystem */
35 #define	XFS_SB_VERSION_NUMBITS		0x000f
36 #define	XFS_SB_VERSION_ALLFBITS		0xfff0
37 #define	XFS_SB_VERSION_ATTRBIT		0x0010
38 #define	XFS_SB_VERSION_NLINKBIT		0x0020
39 #define	XFS_SB_VERSION_QUOTABIT		0x0040
40 #define	XFS_SB_VERSION_ALIGNBIT		0x0080
41 #define	XFS_SB_VERSION_DALIGNBIT	0x0100
42 #define	XFS_SB_VERSION_SHAREDBIT	0x0200
43 #define XFS_SB_VERSION_LOGV2BIT		0x0400
44 #define XFS_SB_VERSION_SECTORBIT	0x0800
45 #define	XFS_SB_VERSION_EXTFLGBIT	0x1000
46 #define	XFS_SB_VERSION_DIRV2BIT		0x2000
47 #define	XFS_SB_VERSION_BORGBIT		0x4000	/* ASCII only case-insens. */
48 #define	XFS_SB_VERSION_MOREBITSBIT	0x8000
49 
50 /*
51  * The size of a single extended attribute on disk is limited by
52  * the size of index values within the attribute entries themselves.
53  * These are be16 fields, so we can only support attribute data
54  * sizes up to 2^16 bytes in length.
55  */
56 #define XFS_XATTR_SIZE_MAX (1 << 16)
57 
58 /*
59  * Supported feature bit list is just all bits in the versionnum field because
60  * we've used them all up and understand them all. Except, of course, for the
61  * shared superblock bit, which nobody knows what it does and so is unsupported.
62  */
63 #define	XFS_SB_VERSION_OKBITS		\
64 	((XFS_SB_VERSION_NUMBITS | XFS_SB_VERSION_ALLFBITS) & \
65 		~XFS_SB_VERSION_SHAREDBIT)
66 
67 /*
68  * There are two words to hold XFS "feature" bits: the original
69  * word, sb_versionnum, and sb_features2.  Whenever a bit is set in
70  * sb_features2, the feature bit XFS_SB_VERSION_MOREBITSBIT must be set.
71  *
72  * These defines represent bits in sb_features2.
73  */
74 #define XFS_SB_VERSION2_RESERVED1BIT	0x00000001
75 #define XFS_SB_VERSION2_LAZYSBCOUNTBIT	0x00000002	/* Superblk counters */
76 #define XFS_SB_VERSION2_RESERVED4BIT	0x00000004
77 #define XFS_SB_VERSION2_ATTR2BIT	0x00000008	/* Inline attr rework */
78 #define XFS_SB_VERSION2_PARENTBIT	0x00000010	/* parent pointers */
79 #define XFS_SB_VERSION2_PROJID32BIT	0x00000080	/* 32 bit project id */
80 #define XFS_SB_VERSION2_CRCBIT		0x00000100	/* metadata CRCs */
81 #define XFS_SB_VERSION2_FTYPE		0x00000200	/* inode type in dir */
82 
83 #define	XFS_SB_VERSION2_OKBITS		\
84 	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
85 	 XFS_SB_VERSION2_ATTR2BIT	| \
86 	 XFS_SB_VERSION2_PROJID32BIT	| \
87 	 XFS_SB_VERSION2_FTYPE)
88 
89 /* Maximum size of the xfs filesystem label, no terminating NULL */
90 #define XFSLABEL_MAX			12
91 
92 /*
93  * Superblock - in core version.  Must be padded to 64 bit alignment.
94  */
95 typedef struct xfs_sb {
96 	uint32_t	sb_magicnum;	/* magic number == XFS_SB_MAGIC */
97 	uint32_t	sb_blocksize;	/* logical block size, bytes */
98 	xfs_rfsblock_t	sb_dblocks;	/* number of data blocks */
99 	xfs_rfsblock_t	sb_rblocks;	/* number of realtime blocks */
100 	xfs_rtbxlen_t	sb_rextents;	/* number of realtime extents */
101 	uuid_t		sb_uuid;	/* user-visible file system unique id */
102 	xfs_fsblock_t	sb_logstart;	/* starting block of log if internal */
103 	xfs_ino_t	sb_rootino;	/* root inode number */
104 	xfs_ino_t	sb_rbmino;	/* bitmap inode for realtime extents */
105 	xfs_ino_t	sb_rsumino;	/* summary inode for rt bitmap */
106 	xfs_agblock_t	sb_rextsize;	/* realtime extent size, blocks */
107 	xfs_agblock_t	sb_agblocks;	/* size of an allocation group */
108 	xfs_agnumber_t	sb_agcount;	/* number of allocation groups */
109 	xfs_extlen_t	sb_rbmblocks;	/* number of rt bitmap blocks */
110 	xfs_extlen_t	sb_logblocks;	/* number of log blocks */
111 	uint16_t	sb_versionnum;	/* header version == XFS_SB_VERSION */
112 	uint16_t	sb_sectsize;	/* volume sector size, bytes */
113 	uint16_t	sb_inodesize;	/* inode size, bytes */
114 	uint16_t	sb_inopblock;	/* inodes per block */
115 	char		sb_fname[XFSLABEL_MAX]; /* file system name */
116 	uint8_t		sb_blocklog;	/* log2 of sb_blocksize */
117 	uint8_t		sb_sectlog;	/* log2 of sb_sectsize */
118 	uint8_t		sb_inodelog;	/* log2 of sb_inodesize */
119 	uint8_t		sb_inopblog;	/* log2 of sb_inopblock */
120 	uint8_t		sb_agblklog;	/* log2 of sb_agblocks (rounded up) */
121 	uint8_t		sb_rextslog;	/* log2 of sb_rextents */
122 	uint8_t		sb_inprogress;	/* mkfs is in progress, don't mount */
123 	uint8_t		sb_imax_pct;	/* max % of fs for inode space */
124 					/* statistics */
125 	/*
126 	 * These fields must remain contiguous.  If you really
127 	 * want to change their layout, make sure you fix the
128 	 * code in xfs_trans_apply_sb_deltas().
129 	 */
130 	uint64_t	sb_icount;	/* allocated inodes */
131 	uint64_t	sb_ifree;	/* free inodes */
132 	uint64_t	sb_fdblocks;	/* free data blocks */
133 	uint64_t	sb_frextents;	/* free realtime extents */
134 	/*
135 	 * End contiguous fields.
136 	 */
137 	xfs_ino_t	sb_uquotino;	/* user quota inode */
138 	xfs_ino_t	sb_gquotino;	/* group quota inode */
139 	uint16_t	sb_qflags;	/* quota flags */
140 	uint8_t		sb_flags;	/* misc. flags */
141 	uint8_t		sb_shared_vn;	/* shared version number */
142 	xfs_extlen_t	sb_inoalignmt;	/* inode chunk alignment, fsblocks */
143 	uint32_t	sb_unit;	/* stripe or raid unit */
144 	uint32_t	sb_width;	/* stripe or raid width */
145 	uint8_t		sb_dirblklog;	/* log2 of dir block size (fsbs) */
146 	uint8_t		sb_logsectlog;	/* log2 of the log sector size */
147 	uint16_t	sb_logsectsize;	/* sector size for the log, bytes */
148 	uint32_t	sb_logsunit;	/* stripe unit size for the log */
149 	uint32_t	sb_features2;	/* additional feature bits */
150 
151 	/*
152 	 * bad features2 field as a result of failing to pad the sb structure to
153 	 * 64 bits. Some machines will be using this field for features2 bits.
154 	 * Easiest just to mark it bad and not use it for anything else.
155 	 *
156 	 * This is not kept up to date in memory; it is always overwritten by
157 	 * the value in sb_features2 when formatting the incore superblock to
158 	 * the disk buffer.
159 	 */
160 	uint32_t	sb_bad_features2;
161 
162 	/* version 5 superblock fields start here */
163 
164 	/* feature masks */
165 	uint32_t	sb_features_compat;
166 	uint32_t	sb_features_ro_compat;
167 	uint32_t	sb_features_incompat;
168 	uint32_t	sb_features_log_incompat;
169 
170 	uint32_t	sb_crc;		/* superblock crc */
171 	xfs_extlen_t	sb_spino_align;	/* sparse inode chunk alignment */
172 
173 	xfs_ino_t	sb_pquotino;	/* project quota inode */
174 	xfs_lsn_t	sb_lsn;		/* last write sequence */
175 	uuid_t		sb_meta_uuid;	/* metadata file system unique id */
176 
177 	xfs_ino_t	sb_metadirino;	/* metadata directory tree root */
178 
179 	xfs_rgnumber_t	sb_rgcount;	/* number of realtime groups */
180 	xfs_rtxlen_t	sb_rgextents;	/* size of a realtime group in rtx */
181 
182 	uint8_t		sb_rgblklog;    /* rt group number shift */
183 	uint8_t		sb_pad[7];	/* zeroes */
184 
185 	/* must be padded to 64 bit alignment */
186 } xfs_sb_t;
187 
188 /*
189  * Superblock - on disk version.
190  * Must be padded to 64 bit alignment.
191  */
192 struct xfs_dsb {
193 	__be32		sb_magicnum;	/* magic number == XFS_SB_MAGIC */
194 	__be32		sb_blocksize;	/* logical block size, bytes */
195 	__be64		sb_dblocks;	/* number of data blocks */
196 	__be64		sb_rblocks;	/* number of realtime blocks */
197 	__be64		sb_rextents;	/* number of realtime extents */
198 	uuid_t		sb_uuid;	/* user-visible file system unique id */
199 	__be64		sb_logstart;	/* starting block of log if internal */
200 	__be64		sb_rootino;	/* root inode number */
201 	__be64		sb_rbmino;	/* bitmap inode for realtime extents */
202 	__be64		sb_rsumino;	/* summary inode for rt bitmap */
203 	__be32		sb_rextsize;	/* realtime extent size, blocks */
204 	__be32		sb_agblocks;	/* size of an allocation group */
205 	__be32		sb_agcount;	/* number of allocation groups */
206 	__be32		sb_rbmblocks;	/* number of rt bitmap blocks */
207 	__be32		sb_logblocks;	/* number of log blocks */
208 	__be16		sb_versionnum;	/* header version == XFS_SB_VERSION */
209 	__be16		sb_sectsize;	/* volume sector size, bytes */
210 	__be16		sb_inodesize;	/* inode size, bytes */
211 	__be16		sb_inopblock;	/* inodes per block */
212 	char		sb_fname[XFSLABEL_MAX]; /* file system name */
213 	__u8		sb_blocklog;	/* log2 of sb_blocksize */
214 	__u8		sb_sectlog;	/* log2 of sb_sectsize */
215 	__u8		sb_inodelog;	/* log2 of sb_inodesize */
216 	__u8		sb_inopblog;	/* log2 of sb_inopblock */
217 	__u8		sb_agblklog;	/* log2 of sb_agblocks (rounded up) */
218 	__u8		sb_rextslog;	/* log2 of sb_rextents */
219 	__u8		sb_inprogress;	/* mkfs is in progress, don't mount */
220 	__u8		sb_imax_pct;	/* max % of fs for inode space */
221 					/* statistics */
222 	/*
223 	 * These fields must remain contiguous.  If you really
224 	 * want to change their layout, make sure you fix the
225 	 * code in xfs_trans_apply_sb_deltas().
226 	 */
227 	__be64		sb_icount;	/* allocated inodes */
228 	__be64		sb_ifree;	/* free inodes */
229 	__be64		sb_fdblocks;	/* free data blocks */
230 	__be64		sb_frextents;	/* free realtime extents */
231 	/*
232 	 * End contiguous fields.
233 	 */
234 	__be64		sb_uquotino;	/* user quota inode */
235 	__be64		sb_gquotino;	/* group quota inode */
236 	__be16		sb_qflags;	/* quota flags */
237 	__u8		sb_flags;	/* misc. flags */
238 	__u8		sb_shared_vn;	/* shared version number */
239 	__be32		sb_inoalignmt;	/* inode chunk alignment, fsblocks */
240 	__be32		sb_unit;	/* stripe or raid unit */
241 	__be32		sb_width;	/* stripe or raid width */
242 	__u8		sb_dirblklog;	/* log2 of dir block size (fsbs) */
243 	__u8		sb_logsectlog;	/* log2 of the log sector size */
244 	__be16		sb_logsectsize;	/* sector size for the log, bytes */
245 	__be32		sb_logsunit;	/* stripe unit size for the log */
246 	__be32		sb_features2;	/* additional feature bits */
247 	/*
248 	 * bad features2 field as a result of failing to pad the sb
249 	 * structure to 64 bits. Some machines will be using this field
250 	 * for features2 bits. Easiest just to mark it bad and not use
251 	 * it for anything else.
252 	 */
253 	__be32		sb_bad_features2;
254 
255 	/* version 5 superblock fields start here */
256 
257 	/* feature masks */
258 	__be32		sb_features_compat;
259 	__be32		sb_features_ro_compat;
260 	__be32		sb_features_incompat;
261 	__be32		sb_features_log_incompat;
262 
263 	__le32		sb_crc;		/* superblock crc */
264 	__be32		sb_spino_align;	/* sparse inode chunk alignment */
265 
266 	__be64		sb_pquotino;	/* project quota inode */
267 	__be64		sb_lsn;		/* last write sequence */
268 	uuid_t		sb_meta_uuid;	/* metadata file system unique id */
269 
270 	__be64		sb_metadirino;	/* metadata directory tree root */
271 	__be32		sb_rgcount;	/* # of realtime groups */
272 	__be32		sb_rgextents;	/* size of rtgroup in rtx */
273 
274 	__u8		sb_rgblklog;    /* rt group number shift */
275 	__u8		sb_pad[7];	/* zeroes */
276 
277 	/*
278 	 * The size of this structure must be padded to 64 bit alignment.
279 	 *
280 	 * NOTE: Don't forget to update secondary_sb_whack in xfs_repair when
281 	 * adding new fields here.
282 	 */
283 };
284 
285 #define XFS_SB_CRC_OFF		offsetof(struct xfs_dsb, sb_crc)
286 
287 /*
288  * Misc. Flags - warning - these will be cleared by xfs_repair unless
289  * a feature bit is set when the flag is used.
290  */
291 #define XFS_SBF_NOFLAGS		0x00	/* no flags set */
292 #define XFS_SBF_READONLY	0x01	/* only read-only mounts allowed */
293 
294 /*
295  * define max. shared version we can interoperate with
296  */
297 #define XFS_SB_MAX_SHARED_VN	0
298 
299 #define	XFS_SB_VERSION_NUM(sbp)	((sbp)->sb_versionnum & XFS_SB_VERSION_NUMBITS)
300 
301 static inline bool xfs_sb_is_v5(const struct xfs_sb *sbp)
302 {
303 	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
304 }
305 
306 /*
307  * Detect a mismatched features2 field.  Older kernels read/wrote
308  * this into the wrong slot, so to be safe we keep them in sync.
309  */
310 static inline bool xfs_sb_has_mismatched_features2(const struct xfs_sb *sbp)
311 {
312 	return sbp->sb_bad_features2 != sbp->sb_features2;
313 }
314 
315 static inline bool xfs_sb_version_hasmorebits(const struct xfs_sb *sbp)
316 {
317 	return xfs_sb_is_v5(sbp) ||
318 	       (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT);
319 }
320 
321 static inline void xfs_sb_version_addattr(struct xfs_sb *sbp)
322 {
323 	sbp->sb_versionnum |= XFS_SB_VERSION_ATTRBIT;
324 }
325 
326 static inline void xfs_sb_version_addquota(struct xfs_sb *sbp)
327 {
328 	sbp->sb_versionnum |= XFS_SB_VERSION_QUOTABIT;
329 }
330 
331 static inline void xfs_sb_version_addattr2(struct xfs_sb *sbp)
332 {
333 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
334 	sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT;
335 }
336 
337 static inline void xfs_sb_version_addprojid32(struct xfs_sb *sbp)
338 {
339 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
340 	sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;
341 }
342 
343 /*
344  * Extended v5 superblock feature masks. These are to be used for new v5
345  * superblock features only.
346  *
347  * Compat features are new features that old kernels will not notice or affect
348  * and so can mount read-write without issues.
349  *
350  * RO-Compat (read only) are features that old kernels can read but will break
351  * if they write. Hence only read-only mounts of such filesystems are allowed on
352  * kernels that don't support the feature bit.
353  *
354  * InCompat features are features which old kernels will not understand and so
355  * must not mount.
356  *
357  * Log-InCompat features are for changes to log formats or new transactions that
358  * can't be replayed on older kernels. The fields are set when the filesystem is
359  * mounted, and a clean unmount clears the fields.
360  */
361 #define XFS_SB_FEAT_COMPAT_ALL 0
362 #define XFS_SB_FEAT_COMPAT_UNKNOWN	~XFS_SB_FEAT_COMPAT_ALL
363 static inline bool
364 xfs_sb_has_compat_feature(
365 	const struct xfs_sb	*sbp,
366 	uint32_t		feature)
367 {
368 	return (sbp->sb_features_compat & feature) != 0;
369 }
370 
371 #define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)		/* free inode btree */
372 #define XFS_SB_FEAT_RO_COMPAT_RMAPBT   (1 << 1)		/* reverse map btree */
373 #define XFS_SB_FEAT_RO_COMPAT_REFLINK  (1 << 2)		/* reflinked files */
374 #define XFS_SB_FEAT_RO_COMPAT_INOBTCNT (1 << 3)		/* inobt block counts */
375 #define XFS_SB_FEAT_RO_COMPAT_ALL \
376 		(XFS_SB_FEAT_RO_COMPAT_FINOBT | \
377 		 XFS_SB_FEAT_RO_COMPAT_RMAPBT | \
378 		 XFS_SB_FEAT_RO_COMPAT_REFLINK| \
379 		 XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
380 #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN	~XFS_SB_FEAT_RO_COMPAT_ALL
381 static inline bool
382 xfs_sb_has_ro_compat_feature(
383 	const struct xfs_sb	*sbp,
384 	uint32_t		feature)
385 {
386 	return (sbp->sb_features_ro_compat & feature) != 0;
387 }
388 
389 #define XFS_SB_FEAT_INCOMPAT_FTYPE	(1 << 0)  /* filetype in dirent */
390 #define XFS_SB_FEAT_INCOMPAT_SPINODES	(1 << 1)  /* sparse inode chunks */
391 #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)  /* metadata UUID */
392 #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)  /* large timestamps */
393 #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4) /* needs xfs_repair */
394 #define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)  /* large extent counters */
395 #define XFS_SB_FEAT_INCOMPAT_EXCHRANGE	(1 << 6)  /* exchangerange supported */
396 #define XFS_SB_FEAT_INCOMPAT_PARENT	(1 << 7)  /* parent pointers */
397 #define XFS_SB_FEAT_INCOMPAT_METADIR	(1 << 8)  /* metadata dir tree */
398 #define XFS_SB_FEAT_INCOMPAT_ALL \
399 		(XFS_SB_FEAT_INCOMPAT_FTYPE | \
400 		 XFS_SB_FEAT_INCOMPAT_SPINODES | \
401 		 XFS_SB_FEAT_INCOMPAT_META_UUID | \
402 		 XFS_SB_FEAT_INCOMPAT_BIGTIME | \
403 		 XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR | \
404 		 XFS_SB_FEAT_INCOMPAT_NREXT64 | \
405 		 XFS_SB_FEAT_INCOMPAT_EXCHRANGE | \
406 		 XFS_SB_FEAT_INCOMPAT_PARENT | \
407 		 XFS_SB_FEAT_INCOMPAT_METADIR)
408 
409 #define XFS_SB_FEAT_INCOMPAT_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_ALL
410 static inline bool
411 xfs_sb_has_incompat_feature(
412 	const struct xfs_sb	*sbp,
413 	uint32_t		feature)
414 {
415 	return (sbp->sb_features_incompat & feature) != 0;
416 }
417 
418 #define XFS_SB_FEAT_INCOMPAT_LOG_XATTRS   (1 << 0)	/* Delayed Attributes */
419 #define XFS_SB_FEAT_INCOMPAT_LOG_ALL \
420 	(XFS_SB_FEAT_INCOMPAT_LOG_XATTRS)
421 #define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_LOG_ALL
422 static inline bool
423 xfs_sb_has_incompat_log_feature(
424 	const struct xfs_sb	*sbp,
425 	uint32_t		feature)
426 {
427 	return (sbp->sb_features_log_incompat & feature) != 0;
428 }
429 
430 static inline void
431 xfs_sb_remove_incompat_log_features(
432 	struct xfs_sb	*sbp)
433 {
434 	sbp->sb_features_log_incompat &= ~XFS_SB_FEAT_INCOMPAT_LOG_ALL;
435 }
436 
437 static inline void
438 xfs_sb_add_incompat_log_features(
439 	struct xfs_sb	*sbp,
440 	unsigned int	features)
441 {
442 	sbp->sb_features_log_incompat |= features;
443 }
444 
445 static inline bool xfs_sb_version_haslogxattrs(const struct xfs_sb *sbp)
446 {
447 	return xfs_sb_is_v5(sbp) && (sbp->sb_features_log_incompat &
448 		 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
449 }
450 
451 static inline bool
452 xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
453 {
454 	return (ino == sbp->sb_uquotino ||
455 		ino == sbp->sb_gquotino ||
456 		ino == sbp->sb_pquotino);
457 }
458 
459 #define XFS_SB_DADDR		((xfs_daddr_t)0) /* daddr in filesystem/ag */
460 #define	XFS_SB_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_SB_DADDR)
461 
462 #define	XFS_HDR_BLOCK(mp,d)	((xfs_agblock_t)XFS_BB_TO_FSBT(mp,d))
463 #define	XFS_DADDR_TO_FSB(mp,d)	XFS_AGB_TO_FSB(mp, \
464 			xfs_daddr_to_agno(mp,d), xfs_daddr_to_agbno(mp,d))
465 #define	XFS_FSB_TO_DADDR(mp,fsbno)	XFS_AGB_TO_DADDR(mp, \
466 			XFS_FSB_TO_AGNO(mp,fsbno), XFS_FSB_TO_AGBNO(mp,fsbno))
467 
468 /*
469  * File system sector to basic block conversions.
470  */
471 #define XFS_FSS_TO_BB(mp,sec)	((sec) << (mp)->m_sectbb_log)
472 
473 /*
474  * File system block to basic block conversions.
475  */
476 #define	XFS_FSB_TO_BB(mp,fsbno)	((fsbno) << (mp)->m_blkbb_log)
477 #define	XFS_BB_TO_FSB(mp,bb)	\
478 	(((bb) + (XFS_FSB_TO_BB(mp,1) - 1)) >> (mp)->m_blkbb_log)
479 #define	XFS_BB_TO_FSBT(mp,bb)	((bb) >> (mp)->m_blkbb_log)
480 
481 /*
482  * File system block to byte conversions.
483  */
484 #define XFS_FSB_TO_B(mp,fsbno)	((xfs_fsize_t)(fsbno) << (mp)->m_sb.sb_blocklog)
485 #define XFS_B_TO_FSB(mp,b)	\
486 	((((uint64_t)(b)) + (mp)->m_blockmask) >> (mp)->m_sb.sb_blocklog)
487 #define XFS_B_TO_FSBT(mp,b)	(((uint64_t)(b)) >> (mp)->m_sb.sb_blocklog)
488 
489 /*
490  * Allocation group header
491  *
492  * This is divided into three structures, placed in sequential 512-byte
493  * buffers after a copy of the superblock (also in a 512-byte buffer).
494  */
495 #define	XFS_AGF_MAGIC	0x58414746	/* 'XAGF' */
496 #define	XFS_AGI_MAGIC	0x58414749	/* 'XAGI' */
497 #define	XFS_AGFL_MAGIC	0x5841464c	/* 'XAFL' */
498 #define	XFS_AGF_VERSION	1
499 #define	XFS_AGI_VERSION	1
500 
501 #define	XFS_AGF_GOOD_VERSION(v)	((v) == XFS_AGF_VERSION)
502 #define	XFS_AGI_GOOD_VERSION(v)	((v) == XFS_AGI_VERSION)
503 
504 /*
505  * agf_cnt_level in the first AGF overlaps the EFS superblock's magic number.
506  * Since the magic numbers valid for EFS are > 64k, our value cannot be confused
507  * for an EFS superblock.
508  */
509 
510 typedef struct xfs_agf {
511 	/*
512 	 * Common allocation group header information
513 	 */
514 	__be32		agf_magicnum;	/* magic number == XFS_AGF_MAGIC */
515 	__be32		agf_versionnum;	/* header version == XFS_AGF_VERSION */
516 	__be32		agf_seqno;	/* sequence # starting from 0 */
517 	__be32		agf_length;	/* size in blocks of a.g. */
518 	/*
519 	 * Freespace and rmap information
520 	 */
521 	__be32		agf_bno_root;	/* bnobt root block */
522 	__be32		agf_cnt_root;	/* cntbt root block */
523 	__be32		agf_rmap_root;	/* rmapbt root block */
524 
525 	__be32		agf_bno_level;	/* bnobt btree levels */
526 	__be32		agf_cnt_level;	/* cntbt btree levels */
527 	__be32		agf_rmap_level;	/* rmapbt btree levels */
528 
529 	__be32		agf_flfirst;	/* first freelist block's index */
530 	__be32		agf_fllast;	/* last freelist block's index */
531 	__be32		agf_flcount;	/* count of blocks in freelist */
532 	__be32		agf_freeblks;	/* total free blocks */
533 
534 	__be32		agf_longest;	/* longest free space */
535 	__be32		agf_btreeblks;	/* # of blocks held in AGF btrees */
536 	uuid_t		agf_uuid;	/* uuid of filesystem */
537 
538 	__be32		agf_rmap_blocks;	/* rmapbt blocks used */
539 	__be32		agf_refcount_blocks;	/* refcountbt blocks used */
540 
541 	__be32		agf_refcount_root;	/* refcount tree root block */
542 	__be32		agf_refcount_level;	/* refcount btree levels */
543 
544 	/*
545 	 * reserve some contiguous space for future logged fields before we add
546 	 * the unlogged fields. This makes the range logging via flags and
547 	 * structure offsets much simpler.
548 	 */
549 	__be64		agf_spare64[14];
550 
551 	/* unlogged fields, written during buffer writeback. */
552 	__be64		agf_lsn;	/* last write sequence */
553 	__be32		agf_crc;	/* crc of agf sector */
554 	__be32		agf_spare2;
555 
556 	/* structure must be padded to 64 bit alignment */
557 } xfs_agf_t;
558 
559 #define XFS_AGF_CRC_OFF		offsetof(struct xfs_agf, agf_crc)
560 
561 #define	XFS_AGF_MAGICNUM	(1u << 0)
562 #define	XFS_AGF_VERSIONNUM	(1u << 1)
563 #define	XFS_AGF_SEQNO		(1u << 2)
564 #define	XFS_AGF_LENGTH		(1u << 3)
565 #define	XFS_AGF_ROOTS		(1u << 4)
566 #define	XFS_AGF_LEVELS		(1u << 5)
567 #define	XFS_AGF_FLFIRST		(1u << 6)
568 #define	XFS_AGF_FLLAST		(1u << 7)
569 #define	XFS_AGF_FLCOUNT		(1u << 8)
570 #define	XFS_AGF_FREEBLKS	(1u << 9)
571 #define	XFS_AGF_LONGEST		(1u << 10)
572 #define	XFS_AGF_BTREEBLKS	(1u << 11)
573 #define	XFS_AGF_UUID		(1u << 12)
574 #define	XFS_AGF_RMAP_BLOCKS	(1u << 13)
575 #define	XFS_AGF_REFCOUNT_BLOCKS	(1u << 14)
576 #define	XFS_AGF_REFCOUNT_ROOT	(1u << 15)
577 #define	XFS_AGF_REFCOUNT_LEVEL	(1u << 16)
578 #define	XFS_AGF_SPARE64		(1u << 17)
579 #define	XFS_AGF_NUM_BITS	18
580 #define	XFS_AGF_ALL_BITS	((1u << XFS_AGF_NUM_BITS) - 1)
581 
582 #define XFS_AGF_FLAGS \
583 	{ XFS_AGF_MAGICNUM,	"MAGICNUM" }, \
584 	{ XFS_AGF_VERSIONNUM,	"VERSIONNUM" }, \
585 	{ XFS_AGF_SEQNO,	"SEQNO" }, \
586 	{ XFS_AGF_LENGTH,	"LENGTH" }, \
587 	{ XFS_AGF_ROOTS,	"ROOTS" }, \
588 	{ XFS_AGF_LEVELS,	"LEVELS" }, \
589 	{ XFS_AGF_FLFIRST,	"FLFIRST" }, \
590 	{ XFS_AGF_FLLAST,	"FLLAST" }, \
591 	{ XFS_AGF_FLCOUNT,	"FLCOUNT" }, \
592 	{ XFS_AGF_FREEBLKS,	"FREEBLKS" }, \
593 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
594 	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }, \
595 	{ XFS_AGF_UUID,		"UUID" }, \
596 	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }, \
597 	{ XFS_AGF_REFCOUNT_BLOCKS,	"REFCOUNT_BLOCKS" }, \
598 	{ XFS_AGF_REFCOUNT_ROOT,	"REFCOUNT_ROOT" }, \
599 	{ XFS_AGF_REFCOUNT_LEVEL,	"REFCOUNT_LEVEL" }, \
600 	{ XFS_AGF_SPARE64,	"SPARE64" }
601 
602 /* disk block (xfs_daddr_t) in the AG */
603 #define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
604 #define	XFS_AGF_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
605 
606 /*
607  * Size of the unlinked inode hash table in the agi.
608  */
609 #define	XFS_AGI_UNLINKED_BUCKETS	64
610 
611 typedef struct xfs_agi {
612 	/*
613 	 * Common allocation group header information
614 	 */
615 	__be32		agi_magicnum;	/* magic number == XFS_AGI_MAGIC */
616 	__be32		agi_versionnum;	/* header version == XFS_AGI_VERSION */
617 	__be32		agi_seqno;	/* sequence # starting from 0 */
618 	__be32		agi_length;	/* size in blocks of a.g. */
619 	/*
620 	 * Inode information
621 	 * Inodes are mapped by interpreting the inode number, so no
622 	 * mapping data is needed here.
623 	 */
624 	__be32		agi_count;	/* count of allocated inodes */
625 	__be32		agi_root;	/* root of inode btree */
626 	__be32		agi_level;	/* levels in inode btree */
627 	__be32		agi_freecount;	/* number of free inodes */
628 
629 	__be32		agi_newino;	/* new inode just allocated */
630 	__be32		agi_dirino;	/* last directory inode chunk */
631 	/*
632 	 * Hash table of inodes which have been unlinked but are
633 	 * still being referenced.
634 	 */
635 	__be32		agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
636 	/*
637 	 * This marks the end of logging region 1 and start of logging region 2.
638 	 */
639 	uuid_t		agi_uuid;	/* uuid of filesystem */
640 	__be32		agi_crc;	/* crc of agi sector */
641 	__be32		agi_pad32;
642 	__be64		agi_lsn;	/* last write sequence */
643 
644 	__be32		agi_free_root; /* root of the free inode btree */
645 	__be32		agi_free_level;/* levels in free inode btree */
646 
647 	__be32		agi_iblocks;	/* inobt blocks used */
648 	__be32		agi_fblocks;	/* finobt blocks used */
649 
650 	/* structure must be padded to 64 bit alignment */
651 } xfs_agi_t;
652 
653 #define XFS_AGI_CRC_OFF		offsetof(struct xfs_agi, agi_crc)
654 
655 #define	XFS_AGI_MAGICNUM	(1u << 0)
656 #define	XFS_AGI_VERSIONNUM	(1u << 1)
657 #define	XFS_AGI_SEQNO		(1u << 2)
658 #define	XFS_AGI_LENGTH		(1u << 3)
659 #define	XFS_AGI_COUNT		(1u << 4)
660 #define	XFS_AGI_ROOT		(1u << 5)
661 #define	XFS_AGI_LEVEL		(1u << 6)
662 #define	XFS_AGI_FREECOUNT	(1u << 7)
663 #define	XFS_AGI_NEWINO		(1u << 8)
664 #define	XFS_AGI_DIRINO		(1u << 9)
665 #define	XFS_AGI_UNLINKED	(1u << 10)
666 #define	XFS_AGI_NUM_BITS_R1	11	/* end of the 1st agi logging region */
667 #define	XFS_AGI_ALL_BITS_R1	((1u << XFS_AGI_NUM_BITS_R1) - 1)
668 #define	XFS_AGI_FREE_ROOT	(1u << 11)
669 #define	XFS_AGI_FREE_LEVEL	(1u << 12)
670 #define	XFS_AGI_IBLOCKS		(1u << 13) /* both inobt/finobt block counters */
671 #define	XFS_AGI_NUM_BITS_R2	14
672 
673 /* disk block (xfs_daddr_t) in the AG */
674 #define XFS_AGI_DADDR(mp)	((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
675 #define	XFS_AGI_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
676 
677 /*
678  * The third a.g. block contains the a.g. freelist, an array
679  * of block pointers to blocks owned by the allocation btree code.
680  */
681 #define XFS_AGFL_DADDR(mp)	((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
682 #define	XFS_AGFL_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
683 #define	XFS_BUF_TO_AGFL(bp)	((struct xfs_agfl *)((bp)->b_addr))
684 
685 struct xfs_agfl {
686 	__be32		agfl_magicnum;
687 	__be32		agfl_seqno;
688 	uuid_t		agfl_uuid;
689 	__be64		agfl_lsn;
690 	__be32		agfl_crc;
691 } __attribute__((packed));
692 
693 #define XFS_AGFL_CRC_OFF	offsetof(struct xfs_agfl, agfl_crc)
694 
695 #define XFS_AGB_TO_FSB(mp,agno,agbno)	\
696 	(((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
697 #define	XFS_FSB_TO_AGNO(mp,fsbno)	\
698 	((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
699 #define	XFS_FSB_TO_AGBNO(mp,fsbno)	\
700 	((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
701 #define	XFS_AGB_TO_DADDR(mp,agno,agbno)	\
702 	((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
703 		(xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
704 #define	XFS_AG_DADDR(mp,agno,d)		(XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
705 
706 /*
707  * For checking for bad ranges of xfs_daddr_t's, covering multiple
708  * allocation groups or a single xfs_daddr_t that's a superblock copy.
709  */
710 #define	XFS_AG_CHECK_DADDR(mp,d,len)	\
711 	((len) == 1 ? \
712 	    ASSERT((d) == XFS_SB_DADDR || \
713 		   xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
714 	    ASSERT(xfs_daddr_to_agno(mp, d) == \
715 		   xfs_daddr_to_agno(mp, (d) + (len) - 1)))
716 
717 /*
718  * Realtime bitmap information is accessed by the word, which is currently
719  * stored in host-endian format.  Starting with the realtime groups feature,
720  * the words are stored in be32 ondisk.
721  */
722 union xfs_rtword_raw {
723 	__u32		old;
724 	__be32		rtg;
725 };
726 
727 /*
728  * Realtime summary counts are accessed by the word, which is currently
729  * stored in host-endian format.  Starting with the realtime groups feature,
730  * the words are stored in be32 ondisk.
731  */
732 union xfs_suminfo_raw {
733 	__u32		old;
734 	__be32		rtg;
735 };
736 
737 /*
738  * Realtime allocation groups break the rt section into multiple pieces that
739  * could be locked independently.  Realtime block group numbers are 32-bit
740  * quantities.  Block numbers within a group are also 32-bit quantities, but
741  * the upper bit must never be set.  rtgroup 0 might have a superblock in it,
742  * so the minimum size of an rtgroup is 2 rtx.
743  */
744 #define XFS_MAX_RGBLOCKS	((xfs_rgblock_t)(1U << 31) - 1)
745 #define XFS_MIN_RGEXTENTS	((xfs_rtxlen_t)2)
746 #define XFS_MAX_RGNUMBER	((xfs_rgnumber_t)(-1U))
747 
748 #define XFS_RTSB_MAGIC	0x46726F67	/* 'Frog' */
749 
750 /*
751  * Realtime superblock - on disk version.  Must be padded to 64 bit alignment.
752  * The first block of the realtime volume contains this superblock.
753  */
754 struct xfs_rtsb {
755 	__be32		rsb_magicnum;	/* magic number == XFS_RTSB_MAGIC */
756 	__le32		rsb_crc;	/* superblock crc */
757 
758 	__be32		rsb_pad;	/* zero */
759 	unsigned char	rsb_fname[XFSLABEL_MAX]; /* file system name */
760 
761 	uuid_t		rsb_uuid;	/* user-visible file system unique id */
762 	uuid_t		rsb_meta_uuid;	/* metadata file system unique id */
763 
764 	/* must be padded to 64 bit alignment */
765 };
766 
767 #define XFS_RTSB_CRC_OFF	offsetof(struct xfs_rtsb, rsb_crc)
768 #define XFS_RTSB_DADDR		((xfs_daddr_t)0) /* daddr in rt section */
769 
770 /*
771  * XFS Timestamps
772  * ==============
773  *
774  * Traditional ondisk inode timestamps consist of signed 32-bit counters for
775  * seconds and nanoseconds; time zero is the Unix epoch, Jan  1 00:00:00 UTC
776  * 1970, which means that the timestamp epoch is the same as the Unix epoch.
777  * Therefore, the ondisk min and max defined here can be used directly to
778  * constrain the incore timestamps on a Unix system.  Note that we actually
779  * encode a __be64 value on disk.
780  *
781  * When the bigtime feature is enabled, ondisk inode timestamps become an
782  * unsigned 64-bit nanoseconds counter.  This means that the bigtime inode
783  * timestamp epoch is the start of the classic timestamp range, which is
784  * Dec 13 20:45:52 UTC 1901.  Because the epochs are not the same, callers
785  * /must/ use the bigtime conversion functions when encoding and decoding raw
786  * timestamps.
787  */
788 typedef __be64 xfs_timestamp_t;
789 
790 /* Legacy timestamp encoding format. */
791 struct xfs_legacy_timestamp {
792 	__be32		t_sec;		/* timestamp seconds */
793 	__be32		t_nsec;		/* timestamp nanoseconds */
794 };
795 
796 /*
797  * Smallest possible ondisk seconds value with traditional timestamps.  This
798  * corresponds exactly with the incore timestamp Dec 13 20:45:52 UTC 1901.
799  */
800 #define XFS_LEGACY_TIME_MIN	((int64_t)S32_MIN)
801 
802 /*
803  * Largest possible ondisk seconds value with traditional timestamps.  This
804  * corresponds exactly with the incore timestamp Jan 19 03:14:07 UTC 2038.
805  */
806 #define XFS_LEGACY_TIME_MAX	((int64_t)S32_MAX)
807 
808 /*
809  * Smallest possible ondisk seconds value with bigtime timestamps.  This
810  * corresponds (after conversion to a Unix timestamp) with the traditional
811  * minimum timestamp of Dec 13 20:45:52 UTC 1901.
812  */
813 #define XFS_BIGTIME_TIME_MIN	((int64_t)0)
814 
815 /*
816  * Largest supported ondisk seconds value with bigtime timestamps.  This
817  * corresponds (after conversion to a Unix timestamp) with an incore timestamp
818  * of Jul  2 20:20:24 UTC 2486.
819  *
820  * We round down the ondisk limit so that the bigtime quota and inode max
821  * timestamps will be the same.
822  */
823 #define XFS_BIGTIME_TIME_MAX	((int64_t)((-1ULL / NSEC_PER_SEC) & ~0x3ULL))
824 
825 /*
826  * Bigtime epoch is set exactly to the minimum time value that a traditional
827  * 32-bit timestamp can represent when using the Unix epoch as a reference.
828  * Hence the Unix epoch is at a fixed offset into the supported bigtime
829  * timestamp range.
830  *
831  * The bigtime epoch also matches the minimum value an on-disk 32-bit XFS
832  * timestamp can represent so we will not lose any fidelity in converting
833  * to/from unix and bigtime timestamps.
834  *
835  * The following conversion factor converts a seconds counter from the Unix
836  * epoch to the bigtime epoch.
837  */
838 #define XFS_BIGTIME_EPOCH_OFFSET	(-(int64_t)S32_MIN)
839 
840 /* Convert a timestamp from the Unix epoch to the bigtime epoch. */
841 static inline uint64_t xfs_unix_to_bigtime(time64_t unix_seconds)
842 {
843 	return (uint64_t)unix_seconds + XFS_BIGTIME_EPOCH_OFFSET;
844 }
845 
846 /* Convert a timestamp from the bigtime epoch to the Unix epoch. */
847 static inline time64_t xfs_bigtime_to_unix(uint64_t ondisk_seconds)
848 {
849 	return (time64_t)ondisk_seconds - XFS_BIGTIME_EPOCH_OFFSET;
850 }
851 
852 enum xfs_metafile_type {
853 	XFS_METAFILE_UNKNOWN,		/* unknown */
854 	XFS_METAFILE_DIR,		/* metadir directory */
855 	XFS_METAFILE_USRQUOTA,		/* user quota */
856 	XFS_METAFILE_GRPQUOTA,		/* group quota */
857 	XFS_METAFILE_PRJQUOTA,		/* project quota */
858 	XFS_METAFILE_RTBITMAP,		/* rt bitmap */
859 	XFS_METAFILE_RTSUMMARY,		/* rt summary */
860 
861 	XFS_METAFILE_MAX
862 } __packed;
863 
864 #define XFS_METAFILE_TYPE_STR \
865 	{ XFS_METAFILE_UNKNOWN,		"unknown" }, \
866 	{ XFS_METAFILE_DIR,		"dir" }, \
867 	{ XFS_METAFILE_USRQUOTA,	"usrquota" }, \
868 	{ XFS_METAFILE_GRPQUOTA,	"grpquota" }, \
869 	{ XFS_METAFILE_PRJQUOTA,	"prjquota" }, \
870 	{ XFS_METAFILE_RTBITMAP,	"rtbitmap" }, \
871 	{ XFS_METAFILE_RTSUMMARY,	"rtsummary" }
872 
873 /*
874  * On-disk inode structure.
875  *
876  * This is just the header or "dinode core", the inode is expanded to fill a
877  * variable size the leftover area split into a data and an attribute fork.
878  * The format of the data and attribute fork depends on the format of the
879  * inode as indicated by di_format and di_aformat.  To access the data and
880  * attribute use the XFS_DFORK_DPTR, XFS_DFORK_APTR, and XFS_DFORK_PTR macros
881  * below.
882  *
883  * There is a very similar struct xfs_log_dinode which matches the layout of
884  * this structure, but is kept in native format instead of big endian.
885  *
886  * Note: di_flushiter is only used by v1/2 inodes - it's effectively a zeroed
887  * padding field for v3 inodes.
888  */
889 #define	XFS_DINODE_MAGIC		0x494e	/* 'IN' */
890 struct xfs_dinode {
891 	__be16		di_magic;	/* inode magic # = XFS_DINODE_MAGIC */
892 	__be16		di_mode;	/* mode and type of file */
893 	__u8		di_version;	/* inode version */
894 	__u8		di_format;	/* format of di_c data */
895 	__be16		di_metatype;	/* XFS_METAFILE_*; was di_onlink */
896 	__be32		di_uid;		/* owner's user id */
897 	__be32		di_gid;		/* owner's group id */
898 	__be32		di_nlink;	/* number of links to file */
899 	__be16		di_projid_lo;	/* lower part of owner's project id */
900 	__be16		di_projid_hi;	/* higher part owner's project id */
901 	union {
902 		/* Number of data fork extents if NREXT64 is set */
903 		__be64	di_big_nextents;
904 
905 		/* Padding for V3 inodes without NREXT64 set. */
906 		__be64	di_v3_pad;
907 
908 		/* Padding and inode flush counter for V2 inodes. */
909 		struct {
910 			__u8	di_v2_pad[6];
911 			__be16	di_flushiter;
912 		};
913 	};
914 	xfs_timestamp_t	di_atime;	/* time last accessed */
915 	xfs_timestamp_t	di_mtime;	/* time last modified */
916 	xfs_timestamp_t	di_ctime;	/* time created/inode modified */
917 	__be64		di_size;	/* number of bytes in file */
918 	__be64		di_nblocks;	/* # of direct & btree blocks used */
919 	__be32		di_extsize;	/* basic/minimum extent size for file */
920 	union {
921 		/*
922 		 * For V2 inodes and V3 inodes without NREXT64 set, this
923 		 * is the number of data and attr fork extents.
924 		 */
925 		struct {
926 			__be32	di_nextents;
927 			__be16	di_anextents;
928 		} __packed;
929 
930 		/* Number of attr fork extents if NREXT64 is set. */
931 		struct {
932 			__be32	di_big_anextents;
933 			__be16	di_nrext64_pad;
934 		} __packed;
935 	} __packed;
936 	__u8		di_forkoff;	/* attr fork offs, <<3 for 64b align */
937 	__s8		di_aformat;	/* format of attr fork's data */
938 	__be32		di_dmevmask;	/* DMIG event mask */
939 	__be16		di_dmstate;	/* DMIG state info */
940 	__be16		di_flags;	/* random flags, XFS_DIFLAG_... */
941 	__be32		di_gen;		/* generation number */
942 
943 	/* di_next_unlinked is the only non-core field in the old dinode */
944 	__be32		di_next_unlinked;/* agi unlinked list ptr */
945 
946 	/* start of the extended dinode, writable fields */
947 	__le32		di_crc;		/* CRC of the inode */
948 	__be64		di_changecount;	/* number of attribute changes */
949 	__be64		di_lsn;		/* flush sequence */
950 	__be64		di_flags2;	/* more random flags */
951 	__be32		di_cowextsize;	/* basic cow extent size for file */
952 	__u8		di_pad2[12];	/* more padding for future expansion */
953 
954 	/* fields only written to during inode creation */
955 	xfs_timestamp_t	di_crtime;	/* time created */
956 	__be64		di_ino;		/* inode number */
957 	uuid_t		di_uuid;	/* UUID of the filesystem */
958 
959 	/* structure must be padded to 64 bit alignment */
960 };
961 
962 #define XFS_DINODE_CRC_OFF	offsetof(struct xfs_dinode, di_crc)
963 
964 #define DI_MAX_FLUSH 0xffff
965 
966 /*
967  * Size of the core inode on disk.  Version 1 and 2 inodes have
968  * the same size, but version 3 has grown a few additional fields.
969  */
970 static inline uint xfs_dinode_size(int version)
971 {
972 	if (version == 3)
973 		return sizeof(struct xfs_dinode);
974 	return offsetof(struct xfs_dinode, di_crc);
975 }
976 
977 /*
978  * The 32 bit link count in the inode theoretically maxes out at UINT_MAX.
979  * Since the pathconf interface is signed, we use 2^31 - 1 instead.
980  */
981 #define	XFS_MAXLINK		((1U << 31) - 1U)
982 
983 /*
984  * Any file that hits the maximum ondisk link count should be pinned to avoid
985  * a use-after-free situation.
986  */
987 #define	XFS_NLINK_PINNED	(~0U)
988 
989 /*
990  * Values for di_format
991  *
992  * This enum is used in string mapping in xfs_trace.h; please keep the
993  * TRACE_DEFINE_ENUMs for it up to date.
994  */
995 enum xfs_dinode_fmt {
996 	XFS_DINODE_FMT_DEV,		/* xfs_dev_t */
997 	XFS_DINODE_FMT_LOCAL,		/* bulk data */
998 	XFS_DINODE_FMT_EXTENTS,		/* struct xfs_bmbt_rec */
999 	XFS_DINODE_FMT_BTREE,		/* struct xfs_bmdr_block */
1000 	XFS_DINODE_FMT_UUID		/* added long ago, but never used */
1001 };
1002 
1003 #define XFS_INODE_FORMAT_STR \
1004 	{ XFS_DINODE_FMT_DEV,		"dev" }, \
1005 	{ XFS_DINODE_FMT_LOCAL,		"local" }, \
1006 	{ XFS_DINODE_FMT_EXTENTS,	"extent" }, \
1007 	{ XFS_DINODE_FMT_BTREE,		"btree" }, \
1008 	{ XFS_DINODE_FMT_UUID,		"uuid" }
1009 
1010 /*
1011  * Max values for extnum and aextnum.
1012  *
1013  * The original on-disk extent counts were held in signed fields, resulting in
1014  * maximum extent counts of 2^31 and 2^15 for the data and attr forks
1015  * respectively. Similarly the maximum extent length is limited to 2^21 blocks
1016  * by the 21-bit wide blockcount field of a BMBT extent record.
1017  *
1018  * The newly introduced data fork extent counter can hold a 64-bit value,
1019  * however the maximum number of extents in a file is also limited to 2^54
1020  * extents by the 54-bit wide startoff field of a BMBT extent record.
1021  *
1022  * It is further limited by the maximum supported file size of 2^63
1023  * *bytes*. This leads to a maximum extent count for maximally sized filesystem
1024  * blocks (64kB) of:
1025  *
1026  * 2^63 bytes / 2^16 bytes per block = 2^47 blocks
1027  *
1028  * Rounding up 47 to the nearest multiple of bits-per-byte results in 48. Hence
1029  * 2^48 was chosen as the maximum data fork extent count.
1030  *
1031  * The maximum file size that can be represented by the data fork extent counter
1032  * in the worst case occurs when all extents are 1 block in length and each
1033  * block is 1KB in size.
1034  *
1035  * With XFS_MAX_EXTCNT_DATA_FORK_SMALL representing maximum extent count and
1036  * with 1KB sized blocks, a file can reach upto,
1037  * 1KB * (2^31) = 2TB
1038  *
1039  * This is much larger than the theoretical maximum size of a directory
1040  * i.e. XFS_DIR2_SPACE_SIZE * XFS_DIR2_MAX_SPACES = ~96GB.
1041  *
1042  * Hence, a directory inode can never overflow its data fork extent counter.
1043  */
1044 #define XFS_MAX_EXTCNT_DATA_FORK_LARGE	((xfs_extnum_t)((1ULL << 48) - 1))
1045 #define XFS_MAX_EXTCNT_ATTR_FORK_LARGE	((xfs_extnum_t)((1ULL << 32) - 1))
1046 #define XFS_MAX_EXTCNT_DATA_FORK_SMALL	((xfs_extnum_t)((1ULL << 31) - 1))
1047 #define XFS_MAX_EXTCNT_ATTR_FORK_SMALL	((xfs_extnum_t)((1ULL << 15) - 1))
1048 
1049 /*
1050  * When we upgrade an inode to the large extent counts, the maximum value by
1051  * which the extent count can increase is bound by the change in size of the
1052  * on-disk field. No upgrade operation should ever be adding more than a few
1053  * tens of extents, so if we get a really large value it is a sign of a code bug
1054  * or corruption.
1055  */
1056 #define XFS_MAX_EXTCNT_UPGRADE_NR	\
1057 	min(XFS_MAX_EXTCNT_ATTR_FORK_LARGE - XFS_MAX_EXTCNT_ATTR_FORK_SMALL,	\
1058 	    XFS_MAX_EXTCNT_DATA_FORK_LARGE - XFS_MAX_EXTCNT_DATA_FORK_SMALL)
1059 
1060 /*
1061  * Inode minimum and maximum sizes.
1062  */
1063 #define	XFS_DINODE_MIN_LOG	8
1064 #define	XFS_DINODE_MAX_LOG	11
1065 #define	XFS_DINODE_MIN_SIZE	(1 << XFS_DINODE_MIN_LOG)
1066 #define	XFS_DINODE_MAX_SIZE	(1 << XFS_DINODE_MAX_LOG)
1067 
1068 /*
1069  * Inode size for given fs.
1070  */
1071 #define XFS_DINODE_SIZE(mp) \
1072 	(xfs_has_v3inodes(mp) ? \
1073 		sizeof(struct xfs_dinode) : \
1074 		offsetof(struct xfs_dinode, di_crc))
1075 #define XFS_LITINO(mp) \
1076 	((mp)->m_sb.sb_inodesize - XFS_DINODE_SIZE(mp))
1077 
1078 /*
1079  * Inode data & attribute fork sizes, per inode.
1080  */
1081 #define XFS_DFORK_BOFF(dip)		((int)((dip)->di_forkoff << 3))
1082 
1083 #define XFS_DFORK_DSIZE(dip,mp) \
1084 	((dip)->di_forkoff ? XFS_DFORK_BOFF(dip) : XFS_LITINO(mp))
1085 #define XFS_DFORK_ASIZE(dip,mp) \
1086 	((dip)->di_forkoff ? XFS_LITINO(mp) - XFS_DFORK_BOFF(dip) : 0)
1087 #define XFS_DFORK_SIZE(dip,mp,w) \
1088 	((w) == XFS_DATA_FORK ? \
1089 		XFS_DFORK_DSIZE(dip, mp) : \
1090 		XFS_DFORK_ASIZE(dip, mp))
1091 
1092 #define XFS_DFORK_MAXEXT(dip, mp, w) \
1093 	(XFS_DFORK_SIZE(dip, mp, w) / sizeof(struct xfs_bmbt_rec))
1094 
1095 /*
1096  * Return pointers to the data or attribute forks.
1097  */
1098 #define XFS_DFORK_DPTR(dip) \
1099 	((void *)dip + xfs_dinode_size(dip->di_version))
1100 #define XFS_DFORK_APTR(dip)	\
1101 	(XFS_DFORK_DPTR(dip) + XFS_DFORK_BOFF(dip))
1102 #define XFS_DFORK_PTR(dip,w)	\
1103 	((w) == XFS_DATA_FORK ? XFS_DFORK_DPTR(dip) : XFS_DFORK_APTR(dip))
1104 
1105 #define XFS_DFORK_FORMAT(dip,w) \
1106 	((w) == XFS_DATA_FORK ? \
1107 		(dip)->di_format : \
1108 		(dip)->di_aformat)
1109 
1110 /*
1111  * For block and character special files the 32bit dev_t is stored at the
1112  * beginning of the data fork.
1113  */
1114 static inline xfs_dev_t xfs_dinode_get_rdev(struct xfs_dinode *dip)
1115 {
1116 	return be32_to_cpu(*(__be32 *)XFS_DFORK_DPTR(dip));
1117 }
1118 
1119 static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
1120 {
1121 	*(__be32 *)XFS_DFORK_DPTR(dip) = cpu_to_be32(rdev);
1122 }
1123 
1124 /*
1125  * Values for di_flags
1126  */
1127 #define XFS_DIFLAG_REALTIME_BIT  0	/* file's blocks come from rt area */
1128 #define XFS_DIFLAG_PREALLOC_BIT  1	/* file space has been preallocated */
1129 #define XFS_DIFLAG_NEWRTBM_BIT   2	/* for rtbitmap inode, new format */
1130 #define XFS_DIFLAG_IMMUTABLE_BIT 3	/* inode is immutable */
1131 #define XFS_DIFLAG_APPEND_BIT    4	/* inode is append-only */
1132 #define XFS_DIFLAG_SYNC_BIT      5	/* inode is written synchronously */
1133 #define XFS_DIFLAG_NOATIME_BIT   6	/* do not update atime */
1134 #define XFS_DIFLAG_NODUMP_BIT    7	/* do not dump */
1135 #define XFS_DIFLAG_RTINHERIT_BIT 8	/* create with realtime bit set */
1136 #define XFS_DIFLAG_PROJINHERIT_BIT   9	/* create with parents projid */
1137 #define XFS_DIFLAG_NOSYMLINKS_BIT   10	/* disallow symlink creation */
1138 #define XFS_DIFLAG_EXTSIZE_BIT      11	/* inode extent size allocator hint */
1139 #define XFS_DIFLAG_EXTSZINHERIT_BIT 12	/* inherit inode extent size */
1140 #define XFS_DIFLAG_NODEFRAG_BIT     13	/* do not reorganize/defragment */
1141 #define XFS_DIFLAG_FILESTREAM_BIT   14  /* use filestream allocator */
1142 /* Do not use bit 15, di_flags is legacy and unchanging now */
1143 
1144 #define XFS_DIFLAG_REALTIME      (1 << XFS_DIFLAG_REALTIME_BIT)
1145 #define XFS_DIFLAG_PREALLOC      (1 << XFS_DIFLAG_PREALLOC_BIT)
1146 #define XFS_DIFLAG_NEWRTBM       (1 << XFS_DIFLAG_NEWRTBM_BIT)
1147 #define XFS_DIFLAG_IMMUTABLE     (1 << XFS_DIFLAG_IMMUTABLE_BIT)
1148 #define XFS_DIFLAG_APPEND        (1 << XFS_DIFLAG_APPEND_BIT)
1149 #define XFS_DIFLAG_SYNC          (1 << XFS_DIFLAG_SYNC_BIT)
1150 #define XFS_DIFLAG_NOATIME       (1 << XFS_DIFLAG_NOATIME_BIT)
1151 #define XFS_DIFLAG_NODUMP        (1 << XFS_DIFLAG_NODUMP_BIT)
1152 #define XFS_DIFLAG_RTINHERIT     (1 << XFS_DIFLAG_RTINHERIT_BIT)
1153 #define XFS_DIFLAG_PROJINHERIT   (1 << XFS_DIFLAG_PROJINHERIT_BIT)
1154 #define XFS_DIFLAG_NOSYMLINKS    (1 << XFS_DIFLAG_NOSYMLINKS_BIT)
1155 #define XFS_DIFLAG_EXTSIZE       (1 << XFS_DIFLAG_EXTSIZE_BIT)
1156 #define XFS_DIFLAG_EXTSZINHERIT  (1 << XFS_DIFLAG_EXTSZINHERIT_BIT)
1157 #define XFS_DIFLAG_NODEFRAG      (1 << XFS_DIFLAG_NODEFRAG_BIT)
1158 #define XFS_DIFLAG_FILESTREAM    (1 << XFS_DIFLAG_FILESTREAM_BIT)
1159 
1160 #define XFS_DIFLAG_ANY \
1161 	(XFS_DIFLAG_REALTIME | XFS_DIFLAG_PREALLOC | XFS_DIFLAG_NEWRTBM | \
1162 	 XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND | XFS_DIFLAG_SYNC | \
1163 	 XFS_DIFLAG_NOATIME | XFS_DIFLAG_NODUMP | XFS_DIFLAG_RTINHERIT | \
1164 	 XFS_DIFLAG_PROJINHERIT | XFS_DIFLAG_NOSYMLINKS | XFS_DIFLAG_EXTSIZE | \
1165 	 XFS_DIFLAG_EXTSZINHERIT | XFS_DIFLAG_NODEFRAG | XFS_DIFLAG_FILESTREAM)
1166 
1167 /*
1168  * Values for di_flags2 These start by being exposed to userspace in the upper
1169  * 16 bits of the XFS_XFLAG_s range.
1170  */
1171 /* use DAX for this inode */
1172 #define XFS_DIFLAG2_DAX_BIT		0
1173 
1174 /* file's blocks may be shared */
1175 #define XFS_DIFLAG2_REFLINK_BIT		1
1176 
1177 /* copy on write extent size hint */
1178 #define XFS_DIFLAG2_COWEXTSIZE_BIT	2
1179 
1180 /* big timestamps */
1181 #define XFS_DIFLAG2_BIGTIME_BIT		3
1182 
1183 /* large extent counters */
1184 #define XFS_DIFLAG2_NREXT64_BIT		4
1185 
1186 /*
1187  * The inode contains filesystem metadata and can be found through the metadata
1188  * directory tree.  Metadata inodes must satisfy the following constraints:
1189  *
1190  * - V5 filesystem (and ftype) are enabled;
1191  * - The only valid modes are regular files and directories;
1192  * - The access bits must be zero;
1193  * - DMAPI event and state masks are zero;
1194  * - The user and group IDs must be zero;
1195  * - The project ID can be used as a u32 annotation;
1196  * - The immutable, sync, noatime, nodump, nodefrag flags must be set.
1197  * - The dax flag must not be set.
1198  * - Directories must have nosymlinks set.
1199  *
1200  * These requirements are chosen defensively to minimize the ability of
1201  * userspace to read or modify the contents, should a metadata file ever
1202  * escape to userspace.
1203  *
1204  * There are further constraints on the directory tree itself:
1205  *
1206  * - Metadata inodes must never be resolvable through the root directory;
1207  * - They must never be accessed by userspace;
1208  * - Metadata directory entries must have correct ftype.
1209  *
1210  * Superblock-rooted metadata files must have the METADATA iflag set even
1211  * though they do not have a parent directory.
1212  */
1213 #define XFS_DIFLAG2_METADATA_BIT	5
1214 
1215 #define XFS_DIFLAG2_DAX		(1ULL << XFS_DIFLAG2_DAX_BIT)
1216 #define XFS_DIFLAG2_REFLINK	(1ULL << XFS_DIFLAG2_REFLINK_BIT)
1217 #define XFS_DIFLAG2_COWEXTSIZE	(1ULL << XFS_DIFLAG2_COWEXTSIZE_BIT)
1218 #define XFS_DIFLAG2_BIGTIME	(1ULL << XFS_DIFLAG2_BIGTIME_BIT)
1219 #define XFS_DIFLAG2_NREXT64	(1ULL << XFS_DIFLAG2_NREXT64_BIT)
1220 #define XFS_DIFLAG2_METADATA	(1ULL << XFS_DIFLAG2_METADATA_BIT)
1221 
1222 #define XFS_DIFLAG2_ANY \
1223 	(XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE | \
1224 	 XFS_DIFLAG2_BIGTIME | XFS_DIFLAG2_NREXT64 | XFS_DIFLAG2_METADATA)
1225 
1226 static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip)
1227 {
1228 	return dip->di_version >= 3 &&
1229 	       (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_BIGTIME));
1230 }
1231 
1232 static inline bool xfs_dinode_has_large_extent_counts(
1233 	const struct xfs_dinode *dip)
1234 {
1235 	return dip->di_version >= 3 &&
1236 	       (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_NREXT64));
1237 }
1238 
1239 static inline bool xfs_dinode_is_metadir(const struct xfs_dinode *dip)
1240 {
1241 	return dip->di_version >= 3 &&
1242 	       (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_METADATA));
1243 }
1244 
1245 /*
1246  * Inode number format:
1247  * low inopblog bits - offset in block
1248  * next agblklog bits - block number in ag
1249  * next agno_log bits - ag number
1250  * high agno_log-agblklog-inopblog bits - 0
1251  */
1252 #define	XFS_INO_MASK(k)			(uint32_t)((1ULL << (k)) - 1)
1253 #define	XFS_INO_OFFSET_BITS(mp)		(mp)->m_sb.sb_inopblog
1254 #define	XFS_INO_AGBNO_BITS(mp)		(mp)->m_sb.sb_agblklog
1255 #define	XFS_INO_AGINO_BITS(mp)		((mp)->m_ino_geo.agino_log)
1256 #define	XFS_INO_AGNO_BITS(mp)		(mp)->m_agno_log
1257 #define	XFS_INO_BITS(mp)		\
1258 	XFS_INO_AGNO_BITS(mp) + XFS_INO_AGINO_BITS(mp)
1259 #define	XFS_INO_TO_AGNO(mp,i)		\
1260 	((xfs_agnumber_t)((i) >> XFS_INO_AGINO_BITS(mp)))
1261 #define	XFS_INO_TO_AGINO(mp,i)		\
1262 	((xfs_agino_t)(i) & XFS_INO_MASK(XFS_INO_AGINO_BITS(mp)))
1263 #define	XFS_INO_TO_AGBNO(mp,i)		\
1264 	(((xfs_agblock_t)(i) >> XFS_INO_OFFSET_BITS(mp)) & \
1265 		XFS_INO_MASK(XFS_INO_AGBNO_BITS(mp)))
1266 #define	XFS_INO_TO_OFFSET(mp,i)		\
1267 	((int)(i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
1268 #define	XFS_INO_TO_FSB(mp,i)		\
1269 	XFS_AGB_TO_FSB(mp, XFS_INO_TO_AGNO(mp,i), XFS_INO_TO_AGBNO(mp,i))
1270 #define	XFS_AGINO_TO_INO(mp,a,i)	\
1271 	(((xfs_ino_t)(a) << XFS_INO_AGINO_BITS(mp)) | (i))
1272 #define	XFS_AGINO_TO_AGBNO(mp,i)	((i) >> XFS_INO_OFFSET_BITS(mp))
1273 #define	XFS_AGINO_TO_OFFSET(mp,i)	\
1274 	((i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
1275 #define	XFS_OFFBNO_TO_AGINO(mp,b,o)	\
1276 	((xfs_agino_t)(((b) << XFS_INO_OFFSET_BITS(mp)) | (o)))
1277 #define	XFS_FSB_TO_INO(mp, b)	((xfs_ino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
1278 #define	XFS_AGB_TO_AGINO(mp, b)	((xfs_agino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
1279 
1280 #define	XFS_MAXINUMBER		((xfs_ino_t)((1ULL << 56) - 1ULL))
1281 #define	XFS_MAXINUMBER_32	((xfs_ino_t)((1ULL << 32) - 1ULL))
1282 
1283 /*
1284  * RealTime Device format definitions
1285  */
1286 
1287 /* Min and max rt extent sizes, specified in bytes */
1288 #define	XFS_MAX_RTEXTSIZE	(1024 * 1024 * 1024)	/* 1GB */
1289 #define	XFS_DFL_RTEXTSIZE	(64 * 1024)	        /* 64kB */
1290 #define	XFS_MIN_RTEXTSIZE	(4 * 1024)		/* 4kB */
1291 
1292 /*
1293  * RT bit manipulation macros.
1294  */
1295 #define XFS_RTBITMAP_MAGIC	0x424D505A	/* BMPZ */
1296 #define XFS_RTSUMMARY_MAGIC	0x53554D59	/* SUMY */
1297 
1298 struct xfs_rtbuf_blkinfo {
1299 	__be32		rt_magic;	/* validity check on block */
1300 	__be32		rt_crc;		/* CRC of block */
1301 	__be64		rt_owner;	/* inode that owns the block */
1302 	__be64		rt_blkno;	/* first block of the buffer */
1303 	__be64		rt_lsn;		/* sequence number of last write */
1304 	uuid_t		rt_uuid;	/* filesystem we belong to */
1305 };
1306 
1307 #define XFS_RTBUF_CRC_OFF \
1308 	offsetof(struct xfs_rtbuf_blkinfo, rt_crc)
1309 
1310 /*
1311  * Dquot and dquot block format definitions
1312  */
1313 #define XFS_DQUOT_MAGIC		0x4451		/* 'DQ' */
1314 #define XFS_DQUOT_VERSION	(uint8_t)0x01	/* latest version number */
1315 
1316 #define XFS_DQTYPE_USER		(1u << 0)	/* user dquot record */
1317 #define XFS_DQTYPE_PROJ		(1u << 1)	/* project dquot record */
1318 #define XFS_DQTYPE_GROUP	(1u << 2)	/* group dquot record */
1319 #define XFS_DQTYPE_BIGTIME	(1u << 7)	/* large expiry timestamps */
1320 
1321 /* bitmask to determine if this is a user/group/project dquot */
1322 #define XFS_DQTYPE_REC_MASK	(XFS_DQTYPE_USER | \
1323 				 XFS_DQTYPE_PROJ | \
1324 				 XFS_DQTYPE_GROUP)
1325 
1326 #define XFS_DQTYPE_ANY		(XFS_DQTYPE_REC_MASK | \
1327 				 XFS_DQTYPE_BIGTIME)
1328 
1329 /*
1330  * XFS Quota Timers
1331  * ================
1332  *
1333  * Traditional quota grace period expiration timers are an unsigned 32-bit
1334  * seconds counter; time zero is the Unix epoch, Jan  1 00:00:01 UTC 1970.
1335  * Note that an expiration value of zero means that the quota limit has not
1336  * been reached, and therefore no expiration has been set.  Therefore, the
1337  * ondisk min and max defined here can be used directly to constrain the incore
1338  * quota expiration timestamps on a Unix system.
1339  *
1340  * When bigtime is enabled, we trade two bits of precision to expand the
1341  * expiration timeout range to match that of big inode timestamps.  The min and
1342  * max recorded here are the on-disk limits, not a Unix timestamp.
1343  *
1344  * The grace period for each quota type is stored in the root dquot (id = 0)
1345  * and is applied to a non-root dquot when it exceeds the soft or hard limits.
1346  * The length of quota grace periods are unsigned 32-bit quantities measured in
1347  * units of seconds.  A value of zero means to use the default period.
1348  */
1349 
1350 /*
1351  * Smallest possible ondisk quota expiration value with traditional timestamps.
1352  * This corresponds exactly with the incore expiration Jan  1 00:00:01 UTC 1970.
1353  */
1354 #define XFS_DQ_LEGACY_EXPIRY_MIN	((int64_t)1)
1355 
1356 /*
1357  * Largest possible ondisk quota expiration value with traditional timestamps.
1358  * This corresponds exactly with the incore expiration Feb  7 06:28:15 UTC 2106.
1359  */
1360 #define XFS_DQ_LEGACY_EXPIRY_MAX	((int64_t)U32_MAX)
1361 
1362 /*
1363  * Smallest possible ondisk quota expiration value with bigtime timestamps.
1364  * This corresponds (after conversion to a Unix timestamp) with the incore
1365  * expiration of Jan  1 00:00:04 UTC 1970.
1366  */
1367 #define XFS_DQ_BIGTIME_EXPIRY_MIN	(XFS_DQ_LEGACY_EXPIRY_MIN)
1368 
1369 /*
1370  * Largest supported ondisk quota expiration value with bigtime timestamps.
1371  * This corresponds (after conversion to a Unix timestamp) with an incore
1372  * expiration of Jul  2 20:20:24 UTC 2486.
1373  *
1374  * The ondisk field supports values up to -1U, which corresponds to an incore
1375  * expiration in 2514.  This is beyond the maximum the bigtime inode timestamp,
1376  * so we cap the maximum bigtime quota expiration to the max inode timestamp.
1377  */
1378 #define XFS_DQ_BIGTIME_EXPIRY_MAX	((int64_t)4074815106U)
1379 
1380 /*
1381  * The following conversion factors assist in converting a quota expiration
1382  * timestamp between the incore and ondisk formats.
1383  */
1384 #define XFS_DQ_BIGTIME_SHIFT	(2)
1385 #define XFS_DQ_BIGTIME_SLACK	((int64_t)(1ULL << XFS_DQ_BIGTIME_SHIFT) - 1)
1386 
1387 /* Convert an incore quota expiration timestamp to an ondisk bigtime value. */
1388 static inline uint32_t xfs_dq_unix_to_bigtime(time64_t unix_seconds)
1389 {
1390 	/*
1391 	 * Round the expiration timestamp up to the nearest bigtime timestamp
1392 	 * that we can store, to give users the most time to fix problems.
1393 	 */
1394 	return ((uint64_t)unix_seconds + XFS_DQ_BIGTIME_SLACK) >>
1395 			XFS_DQ_BIGTIME_SHIFT;
1396 }
1397 
1398 /* Convert an ondisk bigtime quota expiration value to an incore timestamp. */
1399 static inline time64_t xfs_dq_bigtime_to_unix(uint32_t ondisk_seconds)
1400 {
1401 	return (time64_t)ondisk_seconds << XFS_DQ_BIGTIME_SHIFT;
1402 }
1403 
1404 /*
1405  * Default quota grace periods, ranging from zero (use the compiled defaults)
1406  * to ~136 years.  These are applied to a non-root dquot that has exceeded
1407  * either limit.
1408  */
1409 #define XFS_DQ_GRACE_MIN		((int64_t)0)
1410 #define XFS_DQ_GRACE_MAX		((int64_t)U32_MAX)
1411 
1412 /* Maximum id value for a quota record */
1413 #define XFS_DQ_ID_MAX			(U32_MAX)
1414 
1415 /*
1416  * This is the main portion of the on-disk representation of quota information
1417  * for a user.  We pad this with some more expansion room to construct the on
1418  * disk structure.
1419  */
1420 struct xfs_disk_dquot {
1421 	__be16		d_magic;	/* dquot magic = XFS_DQUOT_MAGIC */
1422 	__u8		d_version;	/* dquot version */
1423 	__u8		d_type;		/* XFS_DQTYPE_USER/PROJ/GROUP */
1424 	__be32		d_id;		/* user,project,group id */
1425 	__be64		d_blk_hardlimit;/* absolute limit on disk blks */
1426 	__be64		d_blk_softlimit;/* preferred limit on disk blks */
1427 	__be64		d_ino_hardlimit;/* maximum # allocated inodes */
1428 	__be64		d_ino_softlimit;/* preferred inode limit */
1429 	__be64		d_bcount;	/* disk blocks owned by the user */
1430 	__be64		d_icount;	/* inodes owned by the user */
1431 	__be32		d_itimer;	/* zero if within inode limits if not,
1432 					   this is when we refuse service */
1433 	__be32		d_btimer;	/* similar to above; for disk blocks */
1434 	__be16		d_iwarns;	/* warnings issued wrt num inodes */
1435 	__be16		d_bwarns;	/* warnings issued wrt disk blocks */
1436 	__be32		d_pad0;		/* 64 bit align */
1437 	__be64		d_rtb_hardlimit;/* absolute limit on realtime blks */
1438 	__be64		d_rtb_softlimit;/* preferred limit on RT disk blks */
1439 	__be64		d_rtbcount;	/* realtime blocks owned */
1440 	__be32		d_rtbtimer;	/* similar to above; for RT disk blocks */
1441 	__be16		d_rtbwarns;	/* warnings issued wrt RT disk blocks */
1442 	__be16		d_pad;
1443 };
1444 
1445 /*
1446  * This is what goes on disk. This is separated from the xfs_disk_dquot because
1447  * carrying the unnecessary padding would be a waste of memory.
1448  */
1449 struct xfs_dqblk {
1450 	struct xfs_disk_dquot	dd_diskdq; /* portion living incore as well */
1451 	char			dd_fill[4];/* filling for posterity */
1452 
1453 	/*
1454 	 * These two are only present on filesystems with the CRC bits set.
1455 	 */
1456 	__be32		  dd_crc;	/* checksum */
1457 	__be64		  dd_lsn;	/* last modification in log */
1458 	uuid_t		  dd_uuid;	/* location information */
1459 };
1460 
1461 #define XFS_DQUOT_CRC_OFF	offsetof(struct xfs_dqblk, dd_crc)
1462 
1463 /*
1464  * This defines the unit of allocation of dquots.
1465  *
1466  * Currently, it is just one file system block, and a 4K blk contains 30
1467  * (136 * 30 = 4080) dquots. It's probably not worth trying to make
1468  * this more dynamic.
1469  *
1470  * However, if this number is changed, we have to make sure that we don't
1471  * implicitly assume that we do allocations in chunks of a single filesystem
1472  * block in the dquot/xqm code.
1473  *
1474  * This is part of the ondisk format because the structure size is not a power
1475  * of two, which leaves slack at the end of the disk block.
1476  */
1477 #define XFS_DQUOT_CLUSTER_SIZE_FSB	(xfs_filblks_t)1
1478 
1479 /*
1480  * Remote symlink format and access functions.
1481  */
1482 #define XFS_SYMLINK_MAGIC	0x58534c4d	/* XSLM */
1483 
1484 struct xfs_dsymlink_hdr {
1485 	__be32	sl_magic;
1486 	__be32	sl_offset;
1487 	__be32	sl_bytes;
1488 	__be32	sl_crc;
1489 	uuid_t	sl_uuid;
1490 	__be64	sl_owner;
1491 	__be64	sl_blkno;
1492 	__be64	sl_lsn;
1493 };
1494 
1495 #define XFS_SYMLINK_CRC_OFF	offsetof(struct xfs_dsymlink_hdr, sl_crc)
1496 
1497 #define XFS_SYMLINK_MAXLEN	1024
1498 /*
1499  * The maximum pathlen is 1024 bytes. Since the minimum file system
1500  * blocksize is 512 bytes, we can get a max of 3 extents back from
1501  * bmapi when crc headers are taken into account.
1502  */
1503 #define XFS_SYMLINK_MAPS 3
1504 
1505 #define XFS_SYMLINK_BUF_SPACE(mp, bufsize)	\
1506 	((bufsize) - (xfs_has_crc((mp)) ? \
1507 			sizeof(struct xfs_dsymlink_hdr) : 0))
1508 
1509 
1510 /*
1511  * Allocation Btree format definitions
1512  *
1513  * There are two on-disk btrees, one sorted by blockno and one sorted
1514  * by blockcount and blockno.  All blocks look the same to make the code
1515  * simpler; if we have time later, we'll make the optimizations.
1516  */
1517 #define	XFS_ABTB_MAGIC		0x41425442	/* 'ABTB' for bno tree */
1518 #define	XFS_ABTB_CRC_MAGIC	0x41423342	/* 'AB3B' */
1519 #define	XFS_ABTC_MAGIC		0x41425443	/* 'ABTC' for cnt tree */
1520 #define	XFS_ABTC_CRC_MAGIC	0x41423343	/* 'AB3C' */
1521 
1522 /*
1523  * Data record/key structure
1524  */
1525 typedef struct xfs_alloc_rec {
1526 	__be32		ar_startblock;	/* starting block number */
1527 	__be32		ar_blockcount;	/* count of free blocks */
1528 } xfs_alloc_rec_t, xfs_alloc_key_t;
1529 
1530 typedef struct xfs_alloc_rec_incore {
1531 	xfs_agblock_t	ar_startblock;	/* starting block number */
1532 	xfs_extlen_t	ar_blockcount;	/* count of free blocks */
1533 } xfs_alloc_rec_incore_t;
1534 
1535 /* btree pointer type */
1536 typedef __be32 xfs_alloc_ptr_t;
1537 
1538 /*
1539  * Block numbers in the AG:
1540  * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
1541  */
1542 #define	XFS_BNO_BLOCK(mp)	((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
1543 #define	XFS_CNT_BLOCK(mp)	((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
1544 
1545 
1546 /*
1547  * Inode Allocation Btree format definitions
1548  *
1549  * There is a btree for the inode map per allocation group.
1550  */
1551 #define	XFS_IBT_MAGIC		0x49414254	/* 'IABT' */
1552 #define	XFS_IBT_CRC_MAGIC	0x49414233	/* 'IAB3' */
1553 #define	XFS_FIBT_MAGIC		0x46494254	/* 'FIBT' */
1554 #define	XFS_FIBT_CRC_MAGIC	0x46494233	/* 'FIB3' */
1555 
1556 typedef uint64_t	xfs_inofree_t;
1557 #define	XFS_INODES_PER_CHUNK		(NBBY * sizeof(xfs_inofree_t))
1558 #define	XFS_INODES_PER_CHUNK_LOG	(XFS_NBBYLOG + 3)
1559 #define	XFS_INOBT_ALL_FREE		((xfs_inofree_t)-1)
1560 #define	XFS_INOBT_MASK(i)		((xfs_inofree_t)1 << (i))
1561 
1562 #define XFS_INOBT_HOLEMASK_FULL		0	/* holemask for full chunk */
1563 #define XFS_INOBT_HOLEMASK_BITS		(NBBY * sizeof(uint16_t))
1564 #define XFS_INODES_PER_HOLEMASK_BIT	\
1565 	(XFS_INODES_PER_CHUNK / (NBBY * sizeof(uint16_t)))
1566 
1567 static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
1568 {
1569 	return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
1570 }
1571 
1572 /*
1573  * The on-disk inode record structure has two formats. The original "full"
1574  * format uses a 4-byte freecount. The "sparse" format uses a 1-byte freecount
1575  * and replaces the 3 high-order freecount bytes wth the holemask and inode
1576  * count.
1577  *
1578  * The holemask of the sparse record format allows an inode chunk to have holes
1579  * that refer to blocks not owned by the inode record. This facilitates inode
1580  * allocation in the event of severe free space fragmentation.
1581  */
1582 typedef struct xfs_inobt_rec {
1583 	__be32		ir_startino;	/* starting inode number */
1584 	union {
1585 		struct {
1586 			__be32	ir_freecount;	/* count of free inodes */
1587 		} f;
1588 		struct {
1589 			__be16	ir_holemask;/* hole mask for sparse chunks */
1590 			__u8	ir_count;	/* total inode count */
1591 			__u8	ir_freecount;	/* count of free inodes */
1592 		} sp;
1593 	} ir_u;
1594 	__be64		ir_free;	/* free inode mask */
1595 } xfs_inobt_rec_t;
1596 
1597 typedef struct xfs_inobt_rec_incore {
1598 	xfs_agino_t	ir_startino;	/* starting inode number */
1599 	uint16_t	ir_holemask;	/* hole mask for sparse chunks */
1600 	uint8_t		ir_count;	/* total inode count */
1601 	uint8_t		ir_freecount;	/* count of free inodes (set bits) */
1602 	xfs_inofree_t	ir_free;	/* free inode mask */
1603 } xfs_inobt_rec_incore_t;
1604 
1605 static inline bool xfs_inobt_issparse(uint16_t holemask)
1606 {
1607 	/* non-zero holemask represents a sparse rec. */
1608 	return holemask;
1609 }
1610 
1611 /*
1612  * Key structure
1613  */
1614 typedef struct xfs_inobt_key {
1615 	__be32		ir_startino;	/* starting inode number */
1616 } xfs_inobt_key_t;
1617 
1618 /* btree pointer type */
1619 typedef __be32 xfs_inobt_ptr_t;
1620 
1621 /*
1622  * block numbers in the AG.
1623  */
1624 #define	XFS_IBT_BLOCK(mp)		((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))
1625 #define	XFS_FIBT_BLOCK(mp)		((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
1626 
1627 /*
1628  * Reverse mapping btree format definitions
1629  *
1630  * There is a btree for the reverse map per allocation group
1631  */
1632 #define	XFS_RMAP_CRC_MAGIC	0x524d4233	/* 'RMB3' */
1633 
1634 /*
1635  * Ownership info for an extent.  This is used to create reverse-mapping
1636  * entries.
1637  */
1638 #define XFS_OWNER_INFO_ATTR_FORK	(1 << 0)
1639 #define XFS_OWNER_INFO_BMBT_BLOCK	(1 << 1)
1640 struct xfs_owner_info {
1641 	uint64_t		oi_owner;
1642 	xfs_fileoff_t		oi_offset;
1643 	unsigned int		oi_flags;
1644 };
1645 
1646 /*
1647  * Special owner types.
1648  *
1649  * Seeing as we only support up to 8EB, we have the upper bit of the owner field
1650  * to tell us we have a special owner value. We use these for static metadata
1651  * allocated at mkfs/growfs time, as well as for freespace management metadata.
1652  */
1653 #define XFS_RMAP_OWN_NULL	(-1ULL)	/* No owner, for growfs */
1654 #define XFS_RMAP_OWN_UNKNOWN	(-2ULL)	/* Unknown owner, for EFI recovery */
1655 #define XFS_RMAP_OWN_FS		(-3ULL)	/* static fs metadata */
1656 #define XFS_RMAP_OWN_LOG	(-4ULL)	/* static fs metadata */
1657 #define XFS_RMAP_OWN_AG		(-5ULL)	/* AG freespace btree blocks */
1658 #define XFS_RMAP_OWN_INOBT	(-6ULL)	/* Inode btree blocks */
1659 #define XFS_RMAP_OWN_INODES	(-7ULL)	/* Inode chunk */
1660 #define XFS_RMAP_OWN_REFC	(-8ULL) /* refcount tree */
1661 #define XFS_RMAP_OWN_COW	(-9ULL) /* cow allocations */
1662 #define XFS_RMAP_OWN_MIN	(-10ULL) /* guard */
1663 
1664 #define XFS_RMAP_NON_INODE_OWNER(owner)	(!!((owner) & (1ULL << 63)))
1665 
1666 /*
1667  * Data record structure
1668  */
1669 struct xfs_rmap_rec {
1670 	__be32		rm_startblock;	/* extent start block */
1671 	__be32		rm_blockcount;	/* extent length */
1672 	__be64		rm_owner;	/* extent owner */
1673 	__be64		rm_offset;	/* offset within the owner */
1674 };
1675 
1676 /*
1677  * rmap btree record
1678  *  rm_offset:63 is the attribute fork flag
1679  *  rm_offset:62 is the bmbt block flag
1680  *  rm_offset:61 is the unwritten extent flag (same as l0:63 in bmbt)
1681  *  rm_offset:54-60 aren't used and should be zero
1682  *  rm_offset:0-53 is the block offset within the inode
1683  */
1684 #define XFS_RMAP_OFF_ATTR_FORK	((uint64_t)1ULL << 63)
1685 #define XFS_RMAP_OFF_BMBT_BLOCK	((uint64_t)1ULL << 62)
1686 #define XFS_RMAP_OFF_UNWRITTEN	((uint64_t)1ULL << 61)
1687 
1688 #define XFS_RMAP_LEN_MAX	((uint32_t)~0U)
1689 #define XFS_RMAP_OFF_FLAGS	(XFS_RMAP_OFF_ATTR_FORK | \
1690 				 XFS_RMAP_OFF_BMBT_BLOCK | \
1691 				 XFS_RMAP_OFF_UNWRITTEN)
1692 #define XFS_RMAP_OFF_MASK	((uint64_t)0x3FFFFFFFFFFFFFULL)
1693 
1694 #define XFS_RMAP_OFF(off)		((off) & XFS_RMAP_OFF_MASK)
1695 
1696 #define XFS_RMAP_IS_BMBT_BLOCK(off)	(!!((off) & XFS_RMAP_OFF_BMBT_BLOCK))
1697 #define XFS_RMAP_IS_ATTR_FORK(off)	(!!((off) & XFS_RMAP_OFF_ATTR_FORK))
1698 #define XFS_RMAP_IS_UNWRITTEN(len)	(!!((off) & XFS_RMAP_OFF_UNWRITTEN))
1699 
1700 #define RMAPBT_STARTBLOCK_BITLEN	32
1701 #define RMAPBT_BLOCKCOUNT_BITLEN	32
1702 #define RMAPBT_OWNER_BITLEN		64
1703 #define RMAPBT_ATTRFLAG_BITLEN		1
1704 #define RMAPBT_BMBTFLAG_BITLEN		1
1705 #define RMAPBT_EXNTFLAG_BITLEN		1
1706 #define RMAPBT_UNUSED_OFFSET_BITLEN	7
1707 #define RMAPBT_OFFSET_BITLEN		54
1708 
1709 /*
1710  * Key structure
1711  *
1712  * We don't use the length for lookups
1713  */
1714 struct xfs_rmap_key {
1715 	__be32		rm_startblock;	/* extent start block */
1716 	__be64		rm_owner;	/* extent owner */
1717 	__be64		rm_offset;	/* offset within the owner */
1718 } __attribute__((packed));
1719 
1720 /* btree pointer type */
1721 typedef __be32 xfs_rmap_ptr_t;
1722 
1723 #define	XFS_RMAP_BLOCK(mp) \
1724 	(xfs_has_finobt(((mp))) ? \
1725 	 XFS_FIBT_BLOCK(mp) + 1 : \
1726 	 XFS_IBT_BLOCK(mp) + 1)
1727 
1728 /*
1729  * Reference Count Btree format definitions
1730  *
1731  */
1732 #define	XFS_REFC_CRC_MAGIC	0x52334643	/* 'R3FC' */
1733 
1734 unsigned int xfs_refc_block(struct xfs_mount *mp);
1735 
1736 /*
1737  * Data record/key structure
1738  *
1739  * Each record associates a range of physical blocks (starting at
1740  * rc_startblock and ending rc_blockcount blocks later) with a reference
1741  * count (rc_refcount).  Extents that are being used to stage a copy on
1742  * write (CoW) operation are recorded in the refcount btree with a
1743  * refcount of 1.  All other records must have a refcount > 1 and must
1744  * track an extent mapped only by file data forks.
1745  *
1746  * Extents with a single owner (attributes, metadata, non-shared file
1747  * data) are not tracked here.  Free space is also not tracked here.
1748  * This is consistent with pre-reflink XFS.
1749  */
1750 
1751 /*
1752  * Extents that are being used to stage a copy on write are stored
1753  * in the refcount btree with a refcount of 1 and the upper bit set
1754  * on the startblock.  This speeds up mount time deletion of stale
1755  * staging extents because they're all at the right side of the tree.
1756  */
1757 #define XFS_REFC_COWFLAG		(1U << 31)
1758 #define REFCNTBT_COWFLAG_BITLEN		1
1759 #define REFCNTBT_AGBLOCK_BITLEN		31
1760 
1761 struct xfs_refcount_rec {
1762 	__be32		rc_startblock;	/* starting block number */
1763 	__be32		rc_blockcount;	/* count of blocks */
1764 	__be32		rc_refcount;	/* number of inodes linked here */
1765 };
1766 
1767 struct xfs_refcount_key {
1768 	__be32		rc_startblock;	/* starting block number */
1769 };
1770 
1771 #define MAXREFCOUNT	((xfs_nlink_t)~0U)
1772 #define MAXREFCEXTLEN	((xfs_extlen_t)~0U)
1773 
1774 /* btree pointer type */
1775 typedef __be32 xfs_refcount_ptr_t;
1776 
1777 
1778 /*
1779  * BMAP Btree format definitions
1780  *
1781  * This includes both the root block definition that sits inside an inode fork
1782  * and the record/pointer formats for the leaf/node in the blocks.
1783  */
1784 #define XFS_BMAP_MAGIC		0x424d4150	/* 'BMAP' */
1785 #define XFS_BMAP_CRC_MAGIC	0x424d4133	/* 'BMA3' */
1786 
1787 /*
1788  * Bmap root header, on-disk form only.
1789  */
1790 typedef struct xfs_bmdr_block {
1791 	__be16		bb_level;	/* 0 is a leaf */
1792 	__be16		bb_numrecs;	/* current # of data records */
1793 } xfs_bmdr_block_t;
1794 
1795 /*
1796  * Bmap btree record and extent descriptor.
1797  *  l0:63 is an extent flag (value 1 indicates non-normal).
1798  *  l0:9-62 are startoff.
1799  *  l0:0-8 and l1:21-63 are startblock.
1800  *  l1:0-20 are blockcount.
1801  */
1802 #define BMBT_EXNTFLAG_BITLEN	1
1803 #define BMBT_STARTOFF_BITLEN	54
1804 #define BMBT_STARTBLOCK_BITLEN	52
1805 #define BMBT_BLOCKCOUNT_BITLEN	21
1806 
1807 #define BMBT_STARTOFF_MASK	((1ULL << BMBT_STARTOFF_BITLEN) - 1)
1808 #define BMBT_BLOCKCOUNT_MASK	((1ULL << BMBT_BLOCKCOUNT_BITLEN) - 1)
1809 
1810 #define XFS_MAX_BMBT_EXTLEN	((xfs_extlen_t)(BMBT_BLOCKCOUNT_MASK))
1811 
1812 /*
1813  * bmbt records have a file offset (block) field that is 54 bits wide, so this
1814  * is the largest xfs_fileoff_t that we ever expect to see.
1815  */
1816 #define XFS_MAX_FILEOFF		(BMBT_STARTOFF_MASK + BMBT_BLOCKCOUNT_MASK)
1817 
1818 typedef struct xfs_bmbt_rec {
1819 	__be64			l0, l1;
1820 } xfs_bmbt_rec_t;
1821 
1822 typedef uint64_t	xfs_bmbt_rec_base_t;	/* use this for casts */
1823 typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
1824 
1825 /*
1826  * Values and macros for delayed-allocation startblock fields.
1827  */
1828 #define STARTBLOCKVALBITS	17
1829 #define STARTBLOCKMASKBITS	(15 + 20)
1830 #define STARTBLOCKMASK		\
1831 	(((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
1832 
1833 static inline int isnullstartblock(xfs_fsblock_t x)
1834 {
1835 	return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
1836 }
1837 
1838 static inline xfs_fsblock_t nullstartblock(int k)
1839 {
1840 	ASSERT(k < (1 << STARTBLOCKVALBITS));
1841 	return STARTBLOCKMASK | (k);
1842 }
1843 
1844 static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
1845 {
1846 	return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
1847 }
1848 
1849 /*
1850  * Key structure for non-leaf levels of the tree.
1851  */
1852 typedef struct xfs_bmbt_key {
1853 	__be64		br_startoff;	/* starting file offset */
1854 } xfs_bmbt_key_t, xfs_bmdr_key_t;
1855 
1856 /* btree pointer type */
1857 typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
1858 
1859 
1860 /*
1861  * Generic Btree block format definitions
1862  *
1863  * This is a combination of the actual format used on disk for short and long
1864  * format btrees.  The first three fields are shared by both format, but the
1865  * pointers are different and should be used with care.
1866  *
1867  * To get the size of the actual short or long form headers please use the size
1868  * macros below.  Never use sizeof(xfs_btree_block).
1869  *
1870  * The blkno, crc, lsn, owner and uuid fields are only available in filesystems
1871  * with the crc feature bit, and all accesses to them must be conditional on
1872  * that flag.
1873  */
1874 /* short form block header */
1875 struct xfs_btree_block_shdr {
1876 	__be32		bb_leftsib;
1877 	__be32		bb_rightsib;
1878 
1879 	__be64		bb_blkno;
1880 	__be64		bb_lsn;
1881 	uuid_t		bb_uuid;
1882 	__be32		bb_owner;
1883 	__le32		bb_crc;
1884 };
1885 
1886 /* long form block header */
1887 struct xfs_btree_block_lhdr {
1888 	__be64		bb_leftsib;
1889 	__be64		bb_rightsib;
1890 
1891 	__be64		bb_blkno;
1892 	__be64		bb_lsn;
1893 	uuid_t		bb_uuid;
1894 	__be64		bb_owner;
1895 	__le32		bb_crc;
1896 	__be32		bb_pad; /* padding for alignment */
1897 };
1898 
1899 struct xfs_btree_block {
1900 	__be32		bb_magic;	/* magic number for block type */
1901 	__be16		bb_level;	/* 0 is a leaf */
1902 	__be16		bb_numrecs;	/* current # of data records */
1903 	union {
1904 		struct xfs_btree_block_shdr s;
1905 		struct xfs_btree_block_lhdr l;
1906 	} bb_u;				/* rest */
1907 };
1908 
1909 /* size of a short form block */
1910 #define XFS_BTREE_SBLOCK_LEN \
1911 	(offsetof(struct xfs_btree_block, bb_u) + \
1912 	 offsetof(struct xfs_btree_block_shdr, bb_blkno))
1913 /* size of a long form block */
1914 #define XFS_BTREE_LBLOCK_LEN \
1915 	(offsetof(struct xfs_btree_block, bb_u) + \
1916 	 offsetof(struct xfs_btree_block_lhdr, bb_blkno))
1917 
1918 /* sizes of CRC enabled btree blocks */
1919 #define XFS_BTREE_SBLOCK_CRC_LEN \
1920 	(offsetof(struct xfs_btree_block, bb_u) + \
1921 	 sizeof(struct xfs_btree_block_shdr))
1922 #define XFS_BTREE_LBLOCK_CRC_LEN \
1923 	(offsetof(struct xfs_btree_block, bb_u) + \
1924 	 sizeof(struct xfs_btree_block_lhdr))
1925 
1926 #define XFS_BTREE_SBLOCK_CRC_OFF \
1927 	offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
1928 #define XFS_BTREE_LBLOCK_CRC_OFF \
1929 	offsetof(struct xfs_btree_block, bb_u.l.bb_crc)
1930 
1931 /*
1932  * On-disk XFS access control list structure.
1933  */
1934 struct xfs_acl_entry {
1935 	__be32	ae_tag;
1936 	__be32	ae_id;
1937 	__be16	ae_perm;
1938 	__be16	ae_pad;		/* fill the implicit hole in the structure */
1939 };
1940 
1941 struct xfs_acl {
1942 	__be32			acl_cnt;
1943 	struct xfs_acl_entry	acl_entry[];
1944 };
1945 
1946 /*
1947  * The number of ACL entries allowed is defined by the on-disk format.
1948  * For v4 superblocks, that is limited to 25 entries. For v5 superblocks, it is
1949  * limited only by the maximum size of the xattr that stores the information.
1950  */
1951 #define XFS_ACL_MAX_ENTRIES(mp)	\
1952 	(xfs_has_crc(mp) \
1953 		?  (XFS_XATTR_SIZE_MAX - sizeof(struct xfs_acl)) / \
1954 						sizeof(struct xfs_acl_entry) \
1955 		: 25)
1956 
1957 #define XFS_ACL_SIZE(cnt) \
1958 	(sizeof(struct xfs_acl) + \
1959 		sizeof(struct xfs_acl_entry) * cnt)
1960 
1961 #define XFS_ACL_MAX_SIZE(mp) \
1962 	XFS_ACL_SIZE(XFS_ACL_MAX_ENTRIES((mp)))
1963 
1964 
1965 /* On-disk XFS extended attribute names */
1966 #define SGI_ACL_FILE		"SGI_ACL_FILE"
1967 #define SGI_ACL_DEFAULT		"SGI_ACL_DEFAULT"
1968 #define SGI_ACL_FILE_SIZE	(sizeof(SGI_ACL_FILE)-1)
1969 #define SGI_ACL_DEFAULT_SIZE	(sizeof(SGI_ACL_DEFAULT)-1)
1970 
1971 #endif /* __XFS_FORMAT_H__ */
1972