xref: /linux/fs/xfs/libxfs/xfs_format.h (revision 70ab9ec9166db90ab8980aff4f7083512ecddd1f)
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 match the ondisk version below.
94  * Must be padded to 64 bit alignment.
95  */
96 typedef struct xfs_sb {
97 	uint32_t	sb_magicnum;	/* magic number == XFS_SB_MAGIC */
98 	uint32_t	sb_blocksize;	/* logical block size, bytes */
99 	xfs_rfsblock_t	sb_dblocks;	/* number of data blocks */
100 	xfs_rfsblock_t	sb_rblocks;	/* number of realtime blocks */
101 	xfs_rtbxlen_t	sb_rextents;	/* number of realtime extents */
102 	uuid_t		sb_uuid;	/* user-visible file system unique id */
103 	xfs_fsblock_t	sb_logstart;	/* starting block of log if internal */
104 	xfs_ino_t	sb_rootino;	/* root inode number */
105 	xfs_ino_t	sb_rbmino;	/* bitmap inode for realtime extents */
106 	xfs_ino_t	sb_rsumino;	/* summary inode for rt bitmap */
107 	xfs_agblock_t	sb_rextsize;	/* realtime extent size, blocks */
108 	xfs_agblock_t	sb_agblocks;	/* size of an allocation group */
109 	xfs_agnumber_t	sb_agcount;	/* number of allocation groups */
110 	xfs_extlen_t	sb_rbmblocks;	/* number of rt bitmap blocks */
111 	xfs_extlen_t	sb_logblocks;	/* number of log blocks */
112 	uint16_t	sb_versionnum;	/* header version == XFS_SB_VERSION */
113 	uint16_t	sb_sectsize;	/* volume sector size, bytes */
114 	uint16_t	sb_inodesize;	/* inode size, bytes */
115 	uint16_t	sb_inopblock;	/* inodes per block */
116 	char		sb_fname[XFSLABEL_MAX]; /* file system name */
117 	uint8_t		sb_blocklog;	/* log2 of sb_blocksize */
118 	uint8_t		sb_sectlog;	/* log2 of sb_sectsize */
119 	uint8_t		sb_inodelog;	/* log2 of sb_inodesize */
120 	uint8_t		sb_inopblog;	/* log2 of sb_inopblock */
121 	uint8_t		sb_agblklog;	/* log2 of sb_agblocks (rounded up) */
122 	uint8_t		sb_rextslog;	/* log2 of sb_rextents */
123 	uint8_t		sb_inprogress;	/* mkfs is in progress, don't mount */
124 	uint8_t		sb_imax_pct;	/* max % of fs for inode space */
125 					/* statistics */
126 	/*
127 	 * These fields must remain contiguous.  If you really
128 	 * want to change their layout, make sure you fix the
129 	 * code in xfs_trans_apply_sb_deltas().
130 	 */
131 	uint64_t	sb_icount;	/* allocated inodes */
132 	uint64_t	sb_ifree;	/* free inodes */
133 	uint64_t	sb_fdblocks;	/* free data blocks */
134 	uint64_t	sb_frextents;	/* free realtime extents */
135 	/*
136 	 * End contiguous fields.
137 	 */
138 	xfs_ino_t	sb_uquotino;	/* user quota inode */
139 	xfs_ino_t	sb_gquotino;	/* group quota inode */
140 	uint16_t	sb_qflags;	/* quota flags */
141 	uint8_t		sb_flags;	/* misc. flags */
142 	uint8_t		sb_shared_vn;	/* shared version number */
143 	xfs_extlen_t	sb_inoalignmt;	/* inode chunk alignment, fsblocks */
144 	uint32_t	sb_unit;	/* stripe or raid unit */
145 	uint32_t	sb_width;	/* stripe or raid width */
146 	uint8_t		sb_dirblklog;	/* log2 of dir block size (fsbs) */
147 	uint8_t		sb_logsectlog;	/* log2 of the log sector size */
148 	uint16_t	sb_logsectsize;	/* sector size for the log, bytes */
149 	uint32_t	sb_logsunit;	/* stripe unit size for the log */
150 	uint32_t	sb_features2;	/* additional feature bits */
151 
152 	/*
153 	 * bad features2 field as a result of failing to pad the sb structure to
154 	 * 64 bits. Some machines will be using this field for features2 bits.
155 	 * Easiest just to mark it bad and not use it for anything else.
156 	 *
157 	 * This is not kept up to date in memory; it is always overwritten by
158 	 * the value in sb_features2 when formatting the incore superblock to
159 	 * the disk buffer.
160 	 */
161 	uint32_t	sb_bad_features2;
162 
163 	/* version 5 superblock fields start here */
164 
165 	/* feature masks */
166 	uint32_t	sb_features_compat;
167 	uint32_t	sb_features_ro_compat;
168 	uint32_t	sb_features_incompat;
169 	uint32_t	sb_features_log_incompat;
170 
171 	uint32_t	sb_crc;		/* superblock crc */
172 	xfs_extlen_t	sb_spino_align;	/* sparse inode chunk alignment */
173 
174 	xfs_ino_t	sb_pquotino;	/* project quota inode */
175 	xfs_lsn_t	sb_lsn;		/* last write sequence */
176 	uuid_t		sb_meta_uuid;	/* metadata file system unique id */
177 
178 	/* must be padded to 64 bit alignment */
179 } xfs_sb_t;
180 
181 #define XFS_SB_CRC_OFF		offsetof(struct xfs_sb, sb_crc)
182 
183 /*
184  * Superblock - on disk version.  Must match the in core version above.
185  * Must be padded to 64 bit alignment.
186  */
187 struct xfs_dsb {
188 	__be32		sb_magicnum;	/* magic number == XFS_SB_MAGIC */
189 	__be32		sb_blocksize;	/* logical block size, bytes */
190 	__be64		sb_dblocks;	/* number of data blocks */
191 	__be64		sb_rblocks;	/* number of realtime blocks */
192 	__be64		sb_rextents;	/* number of realtime extents */
193 	uuid_t		sb_uuid;	/* user-visible file system unique id */
194 	__be64		sb_logstart;	/* starting block of log if internal */
195 	__be64		sb_rootino;	/* root inode number */
196 	__be64		sb_rbmino;	/* bitmap inode for realtime extents */
197 	__be64		sb_rsumino;	/* summary inode for rt bitmap */
198 	__be32		sb_rextsize;	/* realtime extent size, blocks */
199 	__be32		sb_agblocks;	/* size of an allocation group */
200 	__be32		sb_agcount;	/* number of allocation groups */
201 	__be32		sb_rbmblocks;	/* number of rt bitmap blocks */
202 	__be32		sb_logblocks;	/* number of log blocks */
203 	__be16		sb_versionnum;	/* header version == XFS_SB_VERSION */
204 	__be16		sb_sectsize;	/* volume sector size, bytes */
205 	__be16		sb_inodesize;	/* inode size, bytes */
206 	__be16		sb_inopblock;	/* inodes per block */
207 	char		sb_fname[XFSLABEL_MAX]; /* file system name */
208 	__u8		sb_blocklog;	/* log2 of sb_blocksize */
209 	__u8		sb_sectlog;	/* log2 of sb_sectsize */
210 	__u8		sb_inodelog;	/* log2 of sb_inodesize */
211 	__u8		sb_inopblog;	/* log2 of sb_inopblock */
212 	__u8		sb_agblklog;	/* log2 of sb_agblocks (rounded up) */
213 	__u8		sb_rextslog;	/* log2 of sb_rextents */
214 	__u8		sb_inprogress;	/* mkfs is in progress, don't mount */
215 	__u8		sb_imax_pct;	/* max % of fs for inode space */
216 					/* statistics */
217 	/*
218 	 * These fields must remain contiguous.  If you really
219 	 * want to change their layout, make sure you fix the
220 	 * code in xfs_trans_apply_sb_deltas().
221 	 */
222 	__be64		sb_icount;	/* allocated inodes */
223 	__be64		sb_ifree;	/* free inodes */
224 	__be64		sb_fdblocks;	/* free data blocks */
225 	__be64		sb_frextents;	/* free realtime extents */
226 	/*
227 	 * End contiguous fields.
228 	 */
229 	__be64		sb_uquotino;	/* user quota inode */
230 	__be64		sb_gquotino;	/* group quota inode */
231 	__be16		sb_qflags;	/* quota flags */
232 	__u8		sb_flags;	/* misc. flags */
233 	__u8		sb_shared_vn;	/* shared version number */
234 	__be32		sb_inoalignmt;	/* inode chunk alignment, fsblocks */
235 	__be32		sb_unit;	/* stripe or raid unit */
236 	__be32		sb_width;	/* stripe or raid width */
237 	__u8		sb_dirblklog;	/* log2 of dir block size (fsbs) */
238 	__u8		sb_logsectlog;	/* log2 of the log sector size */
239 	__be16		sb_logsectsize;	/* sector size for the log, bytes */
240 	__be32		sb_logsunit;	/* stripe unit size for the log */
241 	__be32		sb_features2;	/* additional feature bits */
242 	/*
243 	 * bad features2 field as a result of failing to pad the sb
244 	 * structure to 64 bits. Some machines will be using this field
245 	 * for features2 bits. Easiest just to mark it bad and not use
246 	 * it for anything else.
247 	 */
248 	__be32		sb_bad_features2;
249 
250 	/* version 5 superblock fields start here */
251 
252 	/* feature masks */
253 	__be32		sb_features_compat;
254 	__be32		sb_features_ro_compat;
255 	__be32		sb_features_incompat;
256 	__be32		sb_features_log_incompat;
257 
258 	__le32		sb_crc;		/* superblock crc */
259 	__be32		sb_spino_align;	/* sparse inode chunk alignment */
260 
261 	__be64		sb_pquotino;	/* project quota inode */
262 	__be64		sb_lsn;		/* last write sequence */
263 	uuid_t		sb_meta_uuid;	/* metadata file system unique id */
264 
265 	/* must be padded to 64 bit alignment */
266 };
267 
268 /*
269  * Misc. Flags - warning - these will be cleared by xfs_repair unless
270  * a feature bit is set when the flag is used.
271  */
272 #define XFS_SBF_NOFLAGS		0x00	/* no flags set */
273 #define XFS_SBF_READONLY	0x01	/* only read-only mounts allowed */
274 
275 /*
276  * define max. shared version we can interoperate with
277  */
278 #define XFS_SB_MAX_SHARED_VN	0
279 
280 #define	XFS_SB_VERSION_NUM(sbp)	((sbp)->sb_versionnum & XFS_SB_VERSION_NUMBITS)
281 
282 static inline bool xfs_sb_is_v5(struct xfs_sb *sbp)
283 {
284 	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
285 }
286 
287 /*
288  * Detect a mismatched features2 field.  Older kernels read/wrote
289  * this into the wrong slot, so to be safe we keep them in sync.
290  */
291 static inline bool xfs_sb_has_mismatched_features2(struct xfs_sb *sbp)
292 {
293 	return sbp->sb_bad_features2 != sbp->sb_features2;
294 }
295 
296 static inline bool xfs_sb_version_hasmorebits(struct xfs_sb *sbp)
297 {
298 	return xfs_sb_is_v5(sbp) ||
299 	       (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT);
300 }
301 
302 static inline void xfs_sb_version_addattr(struct xfs_sb *sbp)
303 {
304 	sbp->sb_versionnum |= XFS_SB_VERSION_ATTRBIT;
305 }
306 
307 static inline void xfs_sb_version_addquota(struct xfs_sb *sbp)
308 {
309 	sbp->sb_versionnum |= XFS_SB_VERSION_QUOTABIT;
310 }
311 
312 static inline void xfs_sb_version_addattr2(struct xfs_sb *sbp)
313 {
314 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
315 	sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT;
316 }
317 
318 static inline void xfs_sb_version_addprojid32(struct xfs_sb *sbp)
319 {
320 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
321 	sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;
322 }
323 
324 /*
325  * Extended v5 superblock feature masks. These are to be used for new v5
326  * superblock features only.
327  *
328  * Compat features are new features that old kernels will not notice or affect
329  * and so can mount read-write without issues.
330  *
331  * RO-Compat (read only) are features that old kernels can read but will break
332  * if they write. Hence only read-only mounts of such filesystems are allowed on
333  * kernels that don't support the feature bit.
334  *
335  * InCompat features are features which old kernels will not understand and so
336  * must not mount.
337  *
338  * Log-InCompat features are for changes to log formats or new transactions that
339  * can't be replayed on older kernels. The fields are set when the filesystem is
340  * mounted, and a clean unmount clears the fields.
341  */
342 #define XFS_SB_FEAT_COMPAT_ALL 0
343 #define XFS_SB_FEAT_COMPAT_UNKNOWN	~XFS_SB_FEAT_COMPAT_ALL
344 static inline bool
345 xfs_sb_has_compat_feature(
346 	struct xfs_sb	*sbp,
347 	uint32_t	feature)
348 {
349 	return (sbp->sb_features_compat & feature) != 0;
350 }
351 
352 #define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)		/* free inode btree */
353 #define XFS_SB_FEAT_RO_COMPAT_RMAPBT   (1 << 1)		/* reverse map btree */
354 #define XFS_SB_FEAT_RO_COMPAT_REFLINK  (1 << 2)		/* reflinked files */
355 #define XFS_SB_FEAT_RO_COMPAT_INOBTCNT (1 << 3)		/* inobt block counts */
356 #define XFS_SB_FEAT_RO_COMPAT_ALL \
357 		(XFS_SB_FEAT_RO_COMPAT_FINOBT | \
358 		 XFS_SB_FEAT_RO_COMPAT_RMAPBT | \
359 		 XFS_SB_FEAT_RO_COMPAT_REFLINK| \
360 		 XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
361 #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN	~XFS_SB_FEAT_RO_COMPAT_ALL
362 static inline bool
363 xfs_sb_has_ro_compat_feature(
364 	struct xfs_sb	*sbp,
365 	uint32_t	feature)
366 {
367 	return (sbp->sb_features_ro_compat & feature) != 0;
368 }
369 
370 #define XFS_SB_FEAT_INCOMPAT_FTYPE	(1 << 0)	/* filetype in dirent */
371 #define XFS_SB_FEAT_INCOMPAT_SPINODES	(1 << 1)	/* sparse inode chunks */
372 #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
373 #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)	/* large timestamps */
374 #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)	/* needs xfs_repair */
375 #define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)	/* large extent counters */
376 #define XFS_SB_FEAT_INCOMPAT_ALL \
377 		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
378 		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
379 		 XFS_SB_FEAT_INCOMPAT_META_UUID| \
380 		 XFS_SB_FEAT_INCOMPAT_BIGTIME| \
381 		 XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR| \
382 		 XFS_SB_FEAT_INCOMPAT_NREXT64)
383 
384 #define XFS_SB_FEAT_INCOMPAT_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_ALL
385 static inline bool
386 xfs_sb_has_incompat_feature(
387 	struct xfs_sb	*sbp,
388 	uint32_t	feature)
389 {
390 	return (sbp->sb_features_incompat & feature) != 0;
391 }
392 
393 #define XFS_SB_FEAT_INCOMPAT_LOG_XATTRS   (1 << 0)	/* Delayed Attributes */
394 #define XFS_SB_FEAT_INCOMPAT_LOG_ALL \
395 	(XFS_SB_FEAT_INCOMPAT_LOG_XATTRS)
396 #define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_LOG_ALL
397 static inline bool
398 xfs_sb_has_incompat_log_feature(
399 	struct xfs_sb	*sbp,
400 	uint32_t	feature)
401 {
402 	return (sbp->sb_features_log_incompat & feature) != 0;
403 }
404 
405 static inline void
406 xfs_sb_remove_incompat_log_features(
407 	struct xfs_sb	*sbp)
408 {
409 	sbp->sb_features_log_incompat &= ~XFS_SB_FEAT_INCOMPAT_LOG_ALL;
410 }
411 
412 static inline void
413 xfs_sb_add_incompat_log_features(
414 	struct xfs_sb	*sbp,
415 	unsigned int	features)
416 {
417 	sbp->sb_features_log_incompat |= features;
418 }
419 
420 static inline bool xfs_sb_version_haslogxattrs(struct xfs_sb *sbp)
421 {
422 	return xfs_sb_is_v5(sbp) && (sbp->sb_features_log_incompat &
423 		 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
424 }
425 
426 static inline bool
427 xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
428 {
429 	return (ino == sbp->sb_uquotino ||
430 		ino == sbp->sb_gquotino ||
431 		ino == sbp->sb_pquotino);
432 }
433 
434 #define XFS_SB_DADDR		((xfs_daddr_t)0) /* daddr in filesystem/ag */
435 #define	XFS_SB_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_SB_DADDR)
436 
437 #define	XFS_HDR_BLOCK(mp,d)	((xfs_agblock_t)XFS_BB_TO_FSBT(mp,d))
438 #define	XFS_DADDR_TO_FSB(mp,d)	XFS_AGB_TO_FSB(mp, \
439 			xfs_daddr_to_agno(mp,d), xfs_daddr_to_agbno(mp,d))
440 #define	XFS_FSB_TO_DADDR(mp,fsbno)	XFS_AGB_TO_DADDR(mp, \
441 			XFS_FSB_TO_AGNO(mp,fsbno), XFS_FSB_TO_AGBNO(mp,fsbno))
442 
443 /*
444  * File system sector to basic block conversions.
445  */
446 #define XFS_FSS_TO_BB(mp,sec)	((sec) << (mp)->m_sectbb_log)
447 
448 /*
449  * File system block to basic block conversions.
450  */
451 #define	XFS_FSB_TO_BB(mp,fsbno)	((fsbno) << (mp)->m_blkbb_log)
452 #define	XFS_BB_TO_FSB(mp,bb)	\
453 	(((bb) + (XFS_FSB_TO_BB(mp,1) - 1)) >> (mp)->m_blkbb_log)
454 #define	XFS_BB_TO_FSBT(mp,bb)	((bb) >> (mp)->m_blkbb_log)
455 
456 /*
457  * File system block to byte conversions.
458  */
459 #define XFS_FSB_TO_B(mp,fsbno)	((xfs_fsize_t)(fsbno) << (mp)->m_sb.sb_blocklog)
460 #define XFS_B_TO_FSB(mp,b)	\
461 	((((uint64_t)(b)) + (mp)->m_blockmask) >> (mp)->m_sb.sb_blocklog)
462 #define XFS_B_TO_FSBT(mp,b)	(((uint64_t)(b)) >> (mp)->m_sb.sb_blocklog)
463 
464 /*
465  * Allocation group header
466  *
467  * This is divided into three structures, placed in sequential 512-byte
468  * buffers after a copy of the superblock (also in a 512-byte buffer).
469  */
470 #define	XFS_AGF_MAGIC	0x58414746	/* 'XAGF' */
471 #define	XFS_AGI_MAGIC	0x58414749	/* 'XAGI' */
472 #define	XFS_AGFL_MAGIC	0x5841464c	/* 'XAFL' */
473 #define	XFS_AGF_VERSION	1
474 #define	XFS_AGI_VERSION	1
475 
476 #define	XFS_AGF_GOOD_VERSION(v)	((v) == XFS_AGF_VERSION)
477 #define	XFS_AGI_GOOD_VERSION(v)	((v) == XFS_AGI_VERSION)
478 
479 /*
480  * Btree number 0 is bno, 1 is cnt, 2 is rmap. This value gives the size of the
481  * arrays below.
482  */
483 #define	XFS_BTNUM_AGF	((int)XFS_BTNUM_RMAPi + 1)
484 
485 /*
486  * The second word of agf_levels in the first a.g. overlaps the EFS
487  * superblock's magic number.  Since the magic numbers valid for EFS
488  * are > 64k, our value cannot be confused for an EFS superblock's.
489  */
490 
491 typedef struct xfs_agf {
492 	/*
493 	 * Common allocation group header information
494 	 */
495 	__be32		agf_magicnum;	/* magic number == XFS_AGF_MAGIC */
496 	__be32		agf_versionnum;	/* header version == XFS_AGF_VERSION */
497 	__be32		agf_seqno;	/* sequence # starting from 0 */
498 	__be32		agf_length;	/* size in blocks of a.g. */
499 	/*
500 	 * Freespace and rmap information
501 	 */
502 	__be32		agf_roots[XFS_BTNUM_AGF];	/* root blocks */
503 	__be32		agf_levels[XFS_BTNUM_AGF];	/* btree levels */
504 
505 	__be32		agf_flfirst;	/* first freelist block's index */
506 	__be32		agf_fllast;	/* last freelist block's index */
507 	__be32		agf_flcount;	/* count of blocks in freelist */
508 	__be32		agf_freeblks;	/* total free blocks */
509 
510 	__be32		agf_longest;	/* longest free space */
511 	__be32		agf_btreeblks;	/* # of blocks held in AGF btrees */
512 	uuid_t		agf_uuid;	/* uuid of filesystem */
513 
514 	__be32		agf_rmap_blocks;	/* rmapbt blocks used */
515 	__be32		agf_refcount_blocks;	/* refcountbt blocks used */
516 
517 	__be32		agf_refcount_root;	/* refcount tree root block */
518 	__be32		agf_refcount_level;	/* refcount btree levels */
519 
520 	/*
521 	 * reserve some contiguous space for future logged fields before we add
522 	 * the unlogged fields. This makes the range logging via flags and
523 	 * structure offsets much simpler.
524 	 */
525 	__be64		agf_spare64[14];
526 
527 	/* unlogged fields, written during buffer writeback. */
528 	__be64		agf_lsn;	/* last write sequence */
529 	__be32		agf_crc;	/* crc of agf sector */
530 	__be32		agf_spare2;
531 
532 	/* structure must be padded to 64 bit alignment */
533 } xfs_agf_t;
534 
535 #define XFS_AGF_CRC_OFF		offsetof(struct xfs_agf, agf_crc)
536 
537 #define	XFS_AGF_MAGICNUM	(1u << 0)
538 #define	XFS_AGF_VERSIONNUM	(1u << 1)
539 #define	XFS_AGF_SEQNO		(1u << 2)
540 #define	XFS_AGF_LENGTH		(1u << 3)
541 #define	XFS_AGF_ROOTS		(1u << 4)
542 #define	XFS_AGF_LEVELS		(1u << 5)
543 #define	XFS_AGF_FLFIRST		(1u << 6)
544 #define	XFS_AGF_FLLAST		(1u << 7)
545 #define	XFS_AGF_FLCOUNT		(1u << 8)
546 #define	XFS_AGF_FREEBLKS	(1u << 9)
547 #define	XFS_AGF_LONGEST		(1u << 10)
548 #define	XFS_AGF_BTREEBLKS	(1u << 11)
549 #define	XFS_AGF_UUID		(1u << 12)
550 #define	XFS_AGF_RMAP_BLOCKS	(1u << 13)
551 #define	XFS_AGF_REFCOUNT_BLOCKS	(1u << 14)
552 #define	XFS_AGF_REFCOUNT_ROOT	(1u << 15)
553 #define	XFS_AGF_REFCOUNT_LEVEL	(1u << 16)
554 #define	XFS_AGF_SPARE64		(1u << 17)
555 #define	XFS_AGF_NUM_BITS	18
556 #define	XFS_AGF_ALL_BITS	((1u << XFS_AGF_NUM_BITS) - 1)
557 
558 #define XFS_AGF_FLAGS \
559 	{ XFS_AGF_MAGICNUM,	"MAGICNUM" }, \
560 	{ XFS_AGF_VERSIONNUM,	"VERSIONNUM" }, \
561 	{ XFS_AGF_SEQNO,	"SEQNO" }, \
562 	{ XFS_AGF_LENGTH,	"LENGTH" }, \
563 	{ XFS_AGF_ROOTS,	"ROOTS" }, \
564 	{ XFS_AGF_LEVELS,	"LEVELS" }, \
565 	{ XFS_AGF_FLFIRST,	"FLFIRST" }, \
566 	{ XFS_AGF_FLLAST,	"FLLAST" }, \
567 	{ XFS_AGF_FLCOUNT,	"FLCOUNT" }, \
568 	{ XFS_AGF_FREEBLKS,	"FREEBLKS" }, \
569 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
570 	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }, \
571 	{ XFS_AGF_UUID,		"UUID" }, \
572 	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }, \
573 	{ XFS_AGF_REFCOUNT_BLOCKS,	"REFCOUNT_BLOCKS" }, \
574 	{ XFS_AGF_REFCOUNT_ROOT,	"REFCOUNT_ROOT" }, \
575 	{ XFS_AGF_REFCOUNT_LEVEL,	"REFCOUNT_LEVEL" }, \
576 	{ XFS_AGF_SPARE64,	"SPARE64" }
577 
578 /* disk block (xfs_daddr_t) in the AG */
579 #define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
580 #define	XFS_AGF_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
581 
582 /*
583  * Size of the unlinked inode hash table in the agi.
584  */
585 #define	XFS_AGI_UNLINKED_BUCKETS	64
586 
587 typedef struct xfs_agi {
588 	/*
589 	 * Common allocation group header information
590 	 */
591 	__be32		agi_magicnum;	/* magic number == XFS_AGI_MAGIC */
592 	__be32		agi_versionnum;	/* header version == XFS_AGI_VERSION */
593 	__be32		agi_seqno;	/* sequence # starting from 0 */
594 	__be32		agi_length;	/* size in blocks of a.g. */
595 	/*
596 	 * Inode information
597 	 * Inodes are mapped by interpreting the inode number, so no
598 	 * mapping data is needed here.
599 	 */
600 	__be32		agi_count;	/* count of allocated inodes */
601 	__be32		agi_root;	/* root of inode btree */
602 	__be32		agi_level;	/* levels in inode btree */
603 	__be32		agi_freecount;	/* number of free inodes */
604 
605 	__be32		agi_newino;	/* new inode just allocated */
606 	__be32		agi_dirino;	/* last directory inode chunk */
607 	/*
608 	 * Hash table of inodes which have been unlinked but are
609 	 * still being referenced.
610 	 */
611 	__be32		agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
612 	/*
613 	 * This marks the end of logging region 1 and start of logging region 2.
614 	 */
615 	uuid_t		agi_uuid;	/* uuid of filesystem */
616 	__be32		agi_crc;	/* crc of agi sector */
617 	__be32		agi_pad32;
618 	__be64		agi_lsn;	/* last write sequence */
619 
620 	__be32		agi_free_root; /* root of the free inode btree */
621 	__be32		agi_free_level;/* levels in free inode btree */
622 
623 	__be32		agi_iblocks;	/* inobt blocks used */
624 	__be32		agi_fblocks;	/* finobt blocks used */
625 
626 	/* structure must be padded to 64 bit alignment */
627 } xfs_agi_t;
628 
629 #define XFS_AGI_CRC_OFF		offsetof(struct xfs_agi, agi_crc)
630 
631 #define	XFS_AGI_MAGICNUM	(1u << 0)
632 #define	XFS_AGI_VERSIONNUM	(1u << 1)
633 #define	XFS_AGI_SEQNO		(1u << 2)
634 #define	XFS_AGI_LENGTH		(1u << 3)
635 #define	XFS_AGI_COUNT		(1u << 4)
636 #define	XFS_AGI_ROOT		(1u << 5)
637 #define	XFS_AGI_LEVEL		(1u << 6)
638 #define	XFS_AGI_FREECOUNT	(1u << 7)
639 #define	XFS_AGI_NEWINO		(1u << 8)
640 #define	XFS_AGI_DIRINO		(1u << 9)
641 #define	XFS_AGI_UNLINKED	(1u << 10)
642 #define	XFS_AGI_NUM_BITS_R1	11	/* end of the 1st agi logging region */
643 #define	XFS_AGI_ALL_BITS_R1	((1u << XFS_AGI_NUM_BITS_R1) - 1)
644 #define	XFS_AGI_FREE_ROOT	(1u << 11)
645 #define	XFS_AGI_FREE_LEVEL	(1u << 12)
646 #define	XFS_AGI_IBLOCKS		(1u << 13) /* both inobt/finobt block counters */
647 #define	XFS_AGI_NUM_BITS_R2	14
648 
649 /* disk block (xfs_daddr_t) in the AG */
650 #define XFS_AGI_DADDR(mp)	((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
651 #define	XFS_AGI_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
652 
653 /*
654  * The third a.g. block contains the a.g. freelist, an array
655  * of block pointers to blocks owned by the allocation btree code.
656  */
657 #define XFS_AGFL_DADDR(mp)	((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
658 #define	XFS_AGFL_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
659 #define	XFS_BUF_TO_AGFL(bp)	((struct xfs_agfl *)((bp)->b_addr))
660 
661 struct xfs_agfl {
662 	__be32		agfl_magicnum;
663 	__be32		agfl_seqno;
664 	uuid_t		agfl_uuid;
665 	__be64		agfl_lsn;
666 	__be32		agfl_crc;
667 } __attribute__((packed));
668 
669 #define XFS_AGFL_CRC_OFF	offsetof(struct xfs_agfl, agfl_crc)
670 
671 #define XFS_AGB_TO_FSB(mp,agno,agbno)	\
672 	(((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
673 #define	XFS_FSB_TO_AGNO(mp,fsbno)	\
674 	((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
675 #define	XFS_FSB_TO_AGBNO(mp,fsbno)	\
676 	((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
677 #define	XFS_AGB_TO_DADDR(mp,agno,agbno)	\
678 	((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
679 		(xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
680 #define	XFS_AG_DADDR(mp,agno,d)		(XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
681 
682 /*
683  * For checking for bad ranges of xfs_daddr_t's, covering multiple
684  * allocation groups or a single xfs_daddr_t that's a superblock copy.
685  */
686 #define	XFS_AG_CHECK_DADDR(mp,d,len)	\
687 	((len) == 1 ? \
688 	    ASSERT((d) == XFS_SB_DADDR || \
689 		   xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
690 	    ASSERT(xfs_daddr_to_agno(mp, d) == \
691 		   xfs_daddr_to_agno(mp, (d) + (len) - 1)))
692 
693 /*
694  * Realtime bitmap information is accessed by the word, which is currently
695  * stored in host-endian format.
696  */
697 union xfs_rtword_raw {
698 	__u32		old;
699 };
700 
701 /*
702  * Realtime summary counts are accessed by the word, which is currently
703  * stored in host-endian format.
704  */
705 union xfs_suminfo_raw {
706 	__u32		old;
707 };
708 
709 /*
710  * XFS Timestamps
711  * ==============
712  *
713  * Traditional ondisk inode timestamps consist of signed 32-bit counters for
714  * seconds and nanoseconds; time zero is the Unix epoch, Jan  1 00:00:00 UTC
715  * 1970, which means that the timestamp epoch is the same as the Unix epoch.
716  * Therefore, the ondisk min and max defined here can be used directly to
717  * constrain the incore timestamps on a Unix system.  Note that we actually
718  * encode a __be64 value on disk.
719  *
720  * When the bigtime feature is enabled, ondisk inode timestamps become an
721  * unsigned 64-bit nanoseconds counter.  This means that the bigtime inode
722  * timestamp epoch is the start of the classic timestamp range, which is
723  * Dec 13 20:45:52 UTC 1901.  Because the epochs are not the same, callers
724  * /must/ use the bigtime conversion functions when encoding and decoding raw
725  * timestamps.
726  */
727 typedef __be64 xfs_timestamp_t;
728 
729 /* Legacy timestamp encoding format. */
730 struct xfs_legacy_timestamp {
731 	__be32		t_sec;		/* timestamp seconds */
732 	__be32		t_nsec;		/* timestamp nanoseconds */
733 };
734 
735 /*
736  * Smallest possible ondisk seconds value with traditional timestamps.  This
737  * corresponds exactly with the incore timestamp Dec 13 20:45:52 UTC 1901.
738  */
739 #define XFS_LEGACY_TIME_MIN	((int64_t)S32_MIN)
740 
741 /*
742  * Largest possible ondisk seconds value with traditional timestamps.  This
743  * corresponds exactly with the incore timestamp Jan 19 03:14:07 UTC 2038.
744  */
745 #define XFS_LEGACY_TIME_MAX	((int64_t)S32_MAX)
746 
747 /*
748  * Smallest possible ondisk seconds value with bigtime timestamps.  This
749  * corresponds (after conversion to a Unix timestamp) with the traditional
750  * minimum timestamp of Dec 13 20:45:52 UTC 1901.
751  */
752 #define XFS_BIGTIME_TIME_MIN	((int64_t)0)
753 
754 /*
755  * Largest supported ondisk seconds value with bigtime timestamps.  This
756  * corresponds (after conversion to a Unix timestamp) with an incore timestamp
757  * of Jul  2 20:20:24 UTC 2486.
758  *
759  * We round down the ondisk limit so that the bigtime quota and inode max
760  * timestamps will be the same.
761  */
762 #define XFS_BIGTIME_TIME_MAX	((int64_t)((-1ULL / NSEC_PER_SEC) & ~0x3ULL))
763 
764 /*
765  * Bigtime epoch is set exactly to the minimum time value that a traditional
766  * 32-bit timestamp can represent when using the Unix epoch as a reference.
767  * Hence the Unix epoch is at a fixed offset into the supported bigtime
768  * timestamp range.
769  *
770  * The bigtime epoch also matches the minimum value an on-disk 32-bit XFS
771  * timestamp can represent so we will not lose any fidelity in converting
772  * to/from unix and bigtime timestamps.
773  *
774  * The following conversion factor converts a seconds counter from the Unix
775  * epoch to the bigtime epoch.
776  */
777 #define XFS_BIGTIME_EPOCH_OFFSET	(-(int64_t)S32_MIN)
778 
779 /* Convert a timestamp from the Unix epoch to the bigtime epoch. */
780 static inline uint64_t xfs_unix_to_bigtime(time64_t unix_seconds)
781 {
782 	return (uint64_t)unix_seconds + XFS_BIGTIME_EPOCH_OFFSET;
783 }
784 
785 /* Convert a timestamp from the bigtime epoch to the Unix epoch. */
786 static inline time64_t xfs_bigtime_to_unix(uint64_t ondisk_seconds)
787 {
788 	return (time64_t)ondisk_seconds - XFS_BIGTIME_EPOCH_OFFSET;
789 }
790 
791 /*
792  * On-disk inode structure.
793  *
794  * This is just the header or "dinode core", the inode is expanded to fill a
795  * variable size the leftover area split into a data and an attribute fork.
796  * The format of the data and attribute fork depends on the format of the
797  * inode as indicated by di_format and di_aformat.  To access the data and
798  * attribute use the XFS_DFORK_DPTR, XFS_DFORK_APTR, and XFS_DFORK_PTR macros
799  * below.
800  *
801  * There is a very similar struct xfs_log_dinode which matches the layout of
802  * this structure, but is kept in native format instead of big endian.
803  *
804  * Note: di_flushiter is only used by v1/2 inodes - it's effectively a zeroed
805  * padding field for v3 inodes.
806  */
807 #define	XFS_DINODE_MAGIC		0x494e	/* 'IN' */
808 struct xfs_dinode {
809 	__be16		di_magic;	/* inode magic # = XFS_DINODE_MAGIC */
810 	__be16		di_mode;	/* mode and type of file */
811 	__u8		di_version;	/* inode version */
812 	__u8		di_format;	/* format of di_c data */
813 	__be16		di_onlink;	/* old number of links to file */
814 	__be32		di_uid;		/* owner's user id */
815 	__be32		di_gid;		/* owner's group id */
816 	__be32		di_nlink;	/* number of links to file */
817 	__be16		di_projid_lo;	/* lower part of owner's project id */
818 	__be16		di_projid_hi;	/* higher part owner's project id */
819 	union {
820 		/* Number of data fork extents if NREXT64 is set */
821 		__be64	di_big_nextents;
822 
823 		/* Padding for V3 inodes without NREXT64 set. */
824 		__be64	di_v3_pad;
825 
826 		/* Padding and inode flush counter for V2 inodes. */
827 		struct {
828 			__u8	di_v2_pad[6];
829 			__be16	di_flushiter;
830 		};
831 	};
832 	xfs_timestamp_t	di_atime;	/* time last accessed */
833 	xfs_timestamp_t	di_mtime;	/* time last modified */
834 	xfs_timestamp_t	di_ctime;	/* time created/inode modified */
835 	__be64		di_size;	/* number of bytes in file */
836 	__be64		di_nblocks;	/* # of direct & btree blocks used */
837 	__be32		di_extsize;	/* basic/minimum extent size for file */
838 	union {
839 		/*
840 		 * For V2 inodes and V3 inodes without NREXT64 set, this
841 		 * is the number of data and attr fork extents.
842 		 */
843 		struct {
844 			__be32	di_nextents;
845 			__be16	di_anextents;
846 		} __packed;
847 
848 		/* Number of attr fork extents if NREXT64 is set. */
849 		struct {
850 			__be32	di_big_anextents;
851 			__be16	di_nrext64_pad;
852 		} __packed;
853 	} __packed;
854 	__u8		di_forkoff;	/* attr fork offs, <<3 for 64b align */
855 	__s8		di_aformat;	/* format of attr fork's data */
856 	__be32		di_dmevmask;	/* DMIG event mask */
857 	__be16		di_dmstate;	/* DMIG state info */
858 	__be16		di_flags;	/* random flags, XFS_DIFLAG_... */
859 	__be32		di_gen;		/* generation number */
860 
861 	/* di_next_unlinked is the only non-core field in the old dinode */
862 	__be32		di_next_unlinked;/* agi unlinked list ptr */
863 
864 	/* start of the extended dinode, writable fields */
865 	__le32		di_crc;		/* CRC of the inode */
866 	__be64		di_changecount;	/* number of attribute changes */
867 	__be64		di_lsn;		/* flush sequence */
868 	__be64		di_flags2;	/* more random flags */
869 	__be32		di_cowextsize;	/* basic cow extent size for file */
870 	__u8		di_pad2[12];	/* more padding for future expansion */
871 
872 	/* fields only written to during inode creation */
873 	xfs_timestamp_t	di_crtime;	/* time created */
874 	__be64		di_ino;		/* inode number */
875 	uuid_t		di_uuid;	/* UUID of the filesystem */
876 
877 	/* structure must be padded to 64 bit alignment */
878 };
879 
880 #define XFS_DINODE_CRC_OFF	offsetof(struct xfs_dinode, di_crc)
881 
882 #define DI_MAX_FLUSH 0xffff
883 
884 /*
885  * Size of the core inode on disk.  Version 1 and 2 inodes have
886  * the same size, but version 3 has grown a few additional fields.
887  */
888 static inline uint xfs_dinode_size(int version)
889 {
890 	if (version == 3)
891 		return sizeof(struct xfs_dinode);
892 	return offsetof(struct xfs_dinode, di_crc);
893 }
894 
895 /*
896  * The 32 bit link count in the inode theoretically maxes out at UINT_MAX.
897  * Since the pathconf interface is signed, we use 2^31 - 1 instead.
898  */
899 #define	XFS_MAXLINK		((1U << 31) - 1U)
900 
901 /*
902  * Values for di_format
903  *
904  * This enum is used in string mapping in xfs_trace.h; please keep the
905  * TRACE_DEFINE_ENUMs for it up to date.
906  */
907 enum xfs_dinode_fmt {
908 	XFS_DINODE_FMT_DEV,		/* xfs_dev_t */
909 	XFS_DINODE_FMT_LOCAL,		/* bulk data */
910 	XFS_DINODE_FMT_EXTENTS,		/* struct xfs_bmbt_rec */
911 	XFS_DINODE_FMT_BTREE,		/* struct xfs_bmdr_block */
912 	XFS_DINODE_FMT_UUID		/* added long ago, but never used */
913 };
914 
915 #define XFS_INODE_FORMAT_STR \
916 	{ XFS_DINODE_FMT_DEV,		"dev" }, \
917 	{ XFS_DINODE_FMT_LOCAL,		"local" }, \
918 	{ XFS_DINODE_FMT_EXTENTS,	"extent" }, \
919 	{ XFS_DINODE_FMT_BTREE,		"btree" }, \
920 	{ XFS_DINODE_FMT_UUID,		"uuid" }
921 
922 /*
923  * Max values for extnum and aextnum.
924  *
925  * The original on-disk extent counts were held in signed fields, resulting in
926  * maximum extent counts of 2^31 and 2^15 for the data and attr forks
927  * respectively. Similarly the maximum extent length is limited to 2^21 blocks
928  * by the 21-bit wide blockcount field of a BMBT extent record.
929  *
930  * The newly introduced data fork extent counter can hold a 64-bit value,
931  * however the maximum number of extents in a file is also limited to 2^54
932  * extents by the 54-bit wide startoff field of a BMBT extent record.
933  *
934  * It is further limited by the maximum supported file size of 2^63
935  * *bytes*. This leads to a maximum extent count for maximally sized filesystem
936  * blocks (64kB) of:
937  *
938  * 2^63 bytes / 2^16 bytes per block = 2^47 blocks
939  *
940  * Rounding up 47 to the nearest multiple of bits-per-byte results in 48. Hence
941  * 2^48 was chosen as the maximum data fork extent count.
942  *
943  * The maximum file size that can be represented by the data fork extent counter
944  * in the worst case occurs when all extents are 1 block in length and each
945  * block is 1KB in size.
946  *
947  * With XFS_MAX_EXTCNT_DATA_FORK_SMALL representing maximum extent count and
948  * with 1KB sized blocks, a file can reach upto,
949  * 1KB * (2^31) = 2TB
950  *
951  * This is much larger than the theoretical maximum size of a directory
952  * i.e. XFS_DIR2_SPACE_SIZE * XFS_DIR2_MAX_SPACES = ~96GB.
953  *
954  * Hence, a directory inode can never overflow its data fork extent counter.
955  */
956 #define XFS_MAX_EXTCNT_DATA_FORK_LARGE	((xfs_extnum_t)((1ULL << 48) - 1))
957 #define XFS_MAX_EXTCNT_ATTR_FORK_LARGE	((xfs_extnum_t)((1ULL << 32) - 1))
958 #define XFS_MAX_EXTCNT_DATA_FORK_SMALL	((xfs_extnum_t)((1ULL << 31) - 1))
959 #define XFS_MAX_EXTCNT_ATTR_FORK_SMALL	((xfs_extnum_t)((1ULL << 15) - 1))
960 
961 /*
962  * When we upgrade an inode to the large extent counts, the maximum value by
963  * which the extent count can increase is bound by the change in size of the
964  * on-disk field. No upgrade operation should ever be adding more than a few
965  * tens of extents, so if we get a really large value it is a sign of a code bug
966  * or corruption.
967  */
968 #define XFS_MAX_EXTCNT_UPGRADE_NR	\
969 	min(XFS_MAX_EXTCNT_ATTR_FORK_LARGE - XFS_MAX_EXTCNT_ATTR_FORK_SMALL,	\
970 	    XFS_MAX_EXTCNT_DATA_FORK_LARGE - XFS_MAX_EXTCNT_DATA_FORK_SMALL)
971 
972 /*
973  * Inode minimum and maximum sizes.
974  */
975 #define	XFS_DINODE_MIN_LOG	8
976 #define	XFS_DINODE_MAX_LOG	11
977 #define	XFS_DINODE_MIN_SIZE	(1 << XFS_DINODE_MIN_LOG)
978 #define	XFS_DINODE_MAX_SIZE	(1 << XFS_DINODE_MAX_LOG)
979 
980 /*
981  * Inode size for given fs.
982  */
983 #define XFS_DINODE_SIZE(mp) \
984 	(xfs_has_v3inodes(mp) ? \
985 		sizeof(struct xfs_dinode) : \
986 		offsetof(struct xfs_dinode, di_crc))
987 #define XFS_LITINO(mp) \
988 	((mp)->m_sb.sb_inodesize - XFS_DINODE_SIZE(mp))
989 
990 /*
991  * Inode data & attribute fork sizes, per inode.
992  */
993 #define XFS_DFORK_BOFF(dip)		((int)((dip)->di_forkoff << 3))
994 
995 #define XFS_DFORK_DSIZE(dip,mp) \
996 	((dip)->di_forkoff ? XFS_DFORK_BOFF(dip) : XFS_LITINO(mp))
997 #define XFS_DFORK_ASIZE(dip,mp) \
998 	((dip)->di_forkoff ? XFS_LITINO(mp) - XFS_DFORK_BOFF(dip) : 0)
999 #define XFS_DFORK_SIZE(dip,mp,w) \
1000 	((w) == XFS_DATA_FORK ? \
1001 		XFS_DFORK_DSIZE(dip, mp) : \
1002 		XFS_DFORK_ASIZE(dip, mp))
1003 
1004 #define XFS_DFORK_MAXEXT(dip, mp, w) \
1005 	(XFS_DFORK_SIZE(dip, mp, w) / sizeof(struct xfs_bmbt_rec))
1006 
1007 /*
1008  * Return pointers to the data or attribute forks.
1009  */
1010 #define XFS_DFORK_DPTR(dip) \
1011 	((char *)dip + xfs_dinode_size(dip->di_version))
1012 #define XFS_DFORK_APTR(dip)	\
1013 	(XFS_DFORK_DPTR(dip) + XFS_DFORK_BOFF(dip))
1014 #define XFS_DFORK_PTR(dip,w)	\
1015 	((w) == XFS_DATA_FORK ? XFS_DFORK_DPTR(dip) : XFS_DFORK_APTR(dip))
1016 
1017 #define XFS_DFORK_FORMAT(dip,w) \
1018 	((w) == XFS_DATA_FORK ? \
1019 		(dip)->di_format : \
1020 		(dip)->di_aformat)
1021 
1022 /*
1023  * For block and character special files the 32bit dev_t is stored at the
1024  * beginning of the data fork.
1025  */
1026 static inline xfs_dev_t xfs_dinode_get_rdev(struct xfs_dinode *dip)
1027 {
1028 	return be32_to_cpu(*(__be32 *)XFS_DFORK_DPTR(dip));
1029 }
1030 
1031 static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
1032 {
1033 	*(__be32 *)XFS_DFORK_DPTR(dip) = cpu_to_be32(rdev);
1034 }
1035 
1036 /*
1037  * Values for di_flags
1038  */
1039 #define XFS_DIFLAG_REALTIME_BIT  0	/* file's blocks come from rt area */
1040 #define XFS_DIFLAG_PREALLOC_BIT  1	/* file space has been preallocated */
1041 #define XFS_DIFLAG_NEWRTBM_BIT   2	/* for rtbitmap inode, new format */
1042 #define XFS_DIFLAG_IMMUTABLE_BIT 3	/* inode is immutable */
1043 #define XFS_DIFLAG_APPEND_BIT    4	/* inode is append-only */
1044 #define XFS_DIFLAG_SYNC_BIT      5	/* inode is written synchronously */
1045 #define XFS_DIFLAG_NOATIME_BIT   6	/* do not update atime */
1046 #define XFS_DIFLAG_NODUMP_BIT    7	/* do not dump */
1047 #define XFS_DIFLAG_RTINHERIT_BIT 8	/* create with realtime bit set */
1048 #define XFS_DIFLAG_PROJINHERIT_BIT   9	/* create with parents projid */
1049 #define XFS_DIFLAG_NOSYMLINKS_BIT   10	/* disallow symlink creation */
1050 #define XFS_DIFLAG_EXTSIZE_BIT      11	/* inode extent size allocator hint */
1051 #define XFS_DIFLAG_EXTSZINHERIT_BIT 12	/* inherit inode extent size */
1052 #define XFS_DIFLAG_NODEFRAG_BIT     13	/* do not reorganize/defragment */
1053 #define XFS_DIFLAG_FILESTREAM_BIT   14  /* use filestream allocator */
1054 /* Do not use bit 15, di_flags is legacy and unchanging now */
1055 
1056 #define XFS_DIFLAG_REALTIME      (1 << XFS_DIFLAG_REALTIME_BIT)
1057 #define XFS_DIFLAG_PREALLOC      (1 << XFS_DIFLAG_PREALLOC_BIT)
1058 #define XFS_DIFLAG_NEWRTBM       (1 << XFS_DIFLAG_NEWRTBM_BIT)
1059 #define XFS_DIFLAG_IMMUTABLE     (1 << XFS_DIFLAG_IMMUTABLE_BIT)
1060 #define XFS_DIFLAG_APPEND        (1 << XFS_DIFLAG_APPEND_BIT)
1061 #define XFS_DIFLAG_SYNC          (1 << XFS_DIFLAG_SYNC_BIT)
1062 #define XFS_DIFLAG_NOATIME       (1 << XFS_DIFLAG_NOATIME_BIT)
1063 #define XFS_DIFLAG_NODUMP        (1 << XFS_DIFLAG_NODUMP_BIT)
1064 #define XFS_DIFLAG_RTINHERIT     (1 << XFS_DIFLAG_RTINHERIT_BIT)
1065 #define XFS_DIFLAG_PROJINHERIT   (1 << XFS_DIFLAG_PROJINHERIT_BIT)
1066 #define XFS_DIFLAG_NOSYMLINKS    (1 << XFS_DIFLAG_NOSYMLINKS_BIT)
1067 #define XFS_DIFLAG_EXTSIZE       (1 << XFS_DIFLAG_EXTSIZE_BIT)
1068 #define XFS_DIFLAG_EXTSZINHERIT  (1 << XFS_DIFLAG_EXTSZINHERIT_BIT)
1069 #define XFS_DIFLAG_NODEFRAG      (1 << XFS_DIFLAG_NODEFRAG_BIT)
1070 #define XFS_DIFLAG_FILESTREAM    (1 << XFS_DIFLAG_FILESTREAM_BIT)
1071 
1072 #define XFS_DIFLAG_ANY \
1073 	(XFS_DIFLAG_REALTIME | XFS_DIFLAG_PREALLOC | XFS_DIFLAG_NEWRTBM | \
1074 	 XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND | XFS_DIFLAG_SYNC | \
1075 	 XFS_DIFLAG_NOATIME | XFS_DIFLAG_NODUMP | XFS_DIFLAG_RTINHERIT | \
1076 	 XFS_DIFLAG_PROJINHERIT | XFS_DIFLAG_NOSYMLINKS | XFS_DIFLAG_EXTSIZE | \
1077 	 XFS_DIFLAG_EXTSZINHERIT | XFS_DIFLAG_NODEFRAG | XFS_DIFLAG_FILESTREAM)
1078 
1079 /*
1080  * Values for di_flags2 These start by being exposed to userspace in the upper
1081  * 16 bits of the XFS_XFLAG_s range.
1082  */
1083 #define XFS_DIFLAG2_DAX_BIT	0	/* use DAX for this inode */
1084 #define XFS_DIFLAG2_REFLINK_BIT	1	/* file's blocks may be shared */
1085 #define XFS_DIFLAG2_COWEXTSIZE_BIT   2  /* copy on write extent size hint */
1086 #define XFS_DIFLAG2_BIGTIME_BIT	3	/* big timestamps */
1087 #define XFS_DIFLAG2_NREXT64_BIT 4	/* large extent counters */
1088 
1089 #define XFS_DIFLAG2_DAX		(1 << XFS_DIFLAG2_DAX_BIT)
1090 #define XFS_DIFLAG2_REFLINK     (1 << XFS_DIFLAG2_REFLINK_BIT)
1091 #define XFS_DIFLAG2_COWEXTSIZE  (1 << XFS_DIFLAG2_COWEXTSIZE_BIT)
1092 #define XFS_DIFLAG2_BIGTIME	(1 << XFS_DIFLAG2_BIGTIME_BIT)
1093 #define XFS_DIFLAG2_NREXT64	(1 << XFS_DIFLAG2_NREXT64_BIT)
1094 
1095 #define XFS_DIFLAG2_ANY \
1096 	(XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE | \
1097 	 XFS_DIFLAG2_BIGTIME | XFS_DIFLAG2_NREXT64)
1098 
1099 static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip)
1100 {
1101 	return dip->di_version >= 3 &&
1102 	       (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_BIGTIME));
1103 }
1104 
1105 static inline bool xfs_dinode_has_large_extent_counts(
1106 	const struct xfs_dinode *dip)
1107 {
1108 	return dip->di_version >= 3 &&
1109 	       (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_NREXT64));
1110 }
1111 
1112 /*
1113  * Inode number format:
1114  * low inopblog bits - offset in block
1115  * next agblklog bits - block number in ag
1116  * next agno_log bits - ag number
1117  * high agno_log-agblklog-inopblog bits - 0
1118  */
1119 #define	XFS_INO_MASK(k)			(uint32_t)((1ULL << (k)) - 1)
1120 #define	XFS_INO_OFFSET_BITS(mp)		(mp)->m_sb.sb_inopblog
1121 #define	XFS_INO_AGBNO_BITS(mp)		(mp)->m_sb.sb_agblklog
1122 #define	XFS_INO_AGINO_BITS(mp)		((mp)->m_ino_geo.agino_log)
1123 #define	XFS_INO_AGNO_BITS(mp)		(mp)->m_agno_log
1124 #define	XFS_INO_BITS(mp)		\
1125 	XFS_INO_AGNO_BITS(mp) + XFS_INO_AGINO_BITS(mp)
1126 #define	XFS_INO_TO_AGNO(mp,i)		\
1127 	((xfs_agnumber_t)((i) >> XFS_INO_AGINO_BITS(mp)))
1128 #define	XFS_INO_TO_AGINO(mp,i)		\
1129 	((xfs_agino_t)(i) & XFS_INO_MASK(XFS_INO_AGINO_BITS(mp)))
1130 #define	XFS_INO_TO_AGBNO(mp,i)		\
1131 	(((xfs_agblock_t)(i) >> XFS_INO_OFFSET_BITS(mp)) & \
1132 		XFS_INO_MASK(XFS_INO_AGBNO_BITS(mp)))
1133 #define	XFS_INO_TO_OFFSET(mp,i)		\
1134 	((int)(i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
1135 #define	XFS_INO_TO_FSB(mp,i)		\
1136 	XFS_AGB_TO_FSB(mp, XFS_INO_TO_AGNO(mp,i), XFS_INO_TO_AGBNO(mp,i))
1137 #define	XFS_AGINO_TO_INO(mp,a,i)	\
1138 	(((xfs_ino_t)(a) << XFS_INO_AGINO_BITS(mp)) | (i))
1139 #define	XFS_AGINO_TO_AGBNO(mp,i)	((i) >> XFS_INO_OFFSET_BITS(mp))
1140 #define	XFS_AGINO_TO_OFFSET(mp,i)	\
1141 	((i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
1142 #define	XFS_OFFBNO_TO_AGINO(mp,b,o)	\
1143 	((xfs_agino_t)(((b) << XFS_INO_OFFSET_BITS(mp)) | (o)))
1144 #define	XFS_FSB_TO_INO(mp, b)	((xfs_ino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
1145 #define	XFS_AGB_TO_AGINO(mp, b)	((xfs_agino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
1146 
1147 #define	XFS_MAXINUMBER		((xfs_ino_t)((1ULL << 56) - 1ULL))
1148 #define	XFS_MAXINUMBER_32	((xfs_ino_t)((1ULL << 32) - 1ULL))
1149 
1150 /*
1151  * RealTime Device format definitions
1152  */
1153 
1154 /* Min and max rt extent sizes, specified in bytes */
1155 #define	XFS_MAX_RTEXTSIZE	(1024 * 1024 * 1024)	/* 1GB */
1156 #define	XFS_DFL_RTEXTSIZE	(64 * 1024)	        /* 64kB */
1157 #define	XFS_MIN_RTEXTSIZE	(4 * 1024)		/* 4kB */
1158 
1159 #define	XFS_BLOCKSIZE(mp)	((mp)->m_sb.sb_blocksize)
1160 #define	XFS_BLOCKMASK(mp)	((mp)->m_blockmask)
1161 
1162 /*
1163  * RT bit manipulation macros.
1164  */
1165 #define	XFS_RTMIN(a,b)	((a) < (b) ? (a) : (b))
1166 #define	XFS_RTMAX(a,b)	((a) > (b) ? (a) : (b))
1167 
1168 #define	XFS_RTLOBIT(w)	xfs_lowbit32(w)
1169 #define	XFS_RTHIBIT(w)	xfs_highbit32(w)
1170 
1171 #define	XFS_RTBLOCKLOG(b)	xfs_highbit64(b)
1172 
1173 /*
1174  * Dquot and dquot block format definitions
1175  */
1176 #define XFS_DQUOT_MAGIC		0x4451		/* 'DQ' */
1177 #define XFS_DQUOT_VERSION	(uint8_t)0x01	/* latest version number */
1178 
1179 #define XFS_DQTYPE_USER		(1u << 0)	/* user dquot record */
1180 #define XFS_DQTYPE_PROJ		(1u << 1)	/* project dquot record */
1181 #define XFS_DQTYPE_GROUP	(1u << 2)	/* group dquot record */
1182 #define XFS_DQTYPE_BIGTIME	(1u << 7)	/* large expiry timestamps */
1183 
1184 /* bitmask to determine if this is a user/group/project dquot */
1185 #define XFS_DQTYPE_REC_MASK	(XFS_DQTYPE_USER | \
1186 				 XFS_DQTYPE_PROJ | \
1187 				 XFS_DQTYPE_GROUP)
1188 
1189 #define XFS_DQTYPE_ANY		(XFS_DQTYPE_REC_MASK | \
1190 				 XFS_DQTYPE_BIGTIME)
1191 
1192 /*
1193  * XFS Quota Timers
1194  * ================
1195  *
1196  * Traditional quota grace period expiration timers are an unsigned 32-bit
1197  * seconds counter; time zero is the Unix epoch, Jan  1 00:00:01 UTC 1970.
1198  * Note that an expiration value of zero means that the quota limit has not
1199  * been reached, and therefore no expiration has been set.  Therefore, the
1200  * ondisk min and max defined here can be used directly to constrain the incore
1201  * quota expiration timestamps on a Unix system.
1202  *
1203  * When bigtime is enabled, we trade two bits of precision to expand the
1204  * expiration timeout range to match that of big inode timestamps.  The min and
1205  * max recorded here are the on-disk limits, not a Unix timestamp.
1206  *
1207  * The grace period for each quota type is stored in the root dquot (id = 0)
1208  * and is applied to a non-root dquot when it exceeds the soft or hard limits.
1209  * The length of quota grace periods are unsigned 32-bit quantities measured in
1210  * units of seconds.  A value of zero means to use the default period.
1211  */
1212 
1213 /*
1214  * Smallest possible ondisk quota expiration value with traditional timestamps.
1215  * This corresponds exactly with the incore expiration Jan  1 00:00:01 UTC 1970.
1216  */
1217 #define XFS_DQ_LEGACY_EXPIRY_MIN	((int64_t)1)
1218 
1219 /*
1220  * Largest possible ondisk quota expiration value with traditional timestamps.
1221  * This corresponds exactly with the incore expiration Feb  7 06:28:15 UTC 2106.
1222  */
1223 #define XFS_DQ_LEGACY_EXPIRY_MAX	((int64_t)U32_MAX)
1224 
1225 /*
1226  * Smallest possible ondisk quota expiration value with bigtime timestamps.
1227  * This corresponds (after conversion to a Unix timestamp) with the incore
1228  * expiration of Jan  1 00:00:04 UTC 1970.
1229  */
1230 #define XFS_DQ_BIGTIME_EXPIRY_MIN	(XFS_DQ_LEGACY_EXPIRY_MIN)
1231 
1232 /*
1233  * Largest supported ondisk quota expiration value with bigtime timestamps.
1234  * This corresponds (after conversion to a Unix timestamp) with an incore
1235  * expiration of Jul  2 20:20:24 UTC 2486.
1236  *
1237  * The ondisk field supports values up to -1U, which corresponds to an incore
1238  * expiration in 2514.  This is beyond the maximum the bigtime inode timestamp,
1239  * so we cap the maximum bigtime quota expiration to the max inode timestamp.
1240  */
1241 #define XFS_DQ_BIGTIME_EXPIRY_MAX	((int64_t)4074815106U)
1242 
1243 /*
1244  * The following conversion factors assist in converting a quota expiration
1245  * timestamp between the incore and ondisk formats.
1246  */
1247 #define XFS_DQ_BIGTIME_SHIFT	(2)
1248 #define XFS_DQ_BIGTIME_SLACK	((int64_t)(1ULL << XFS_DQ_BIGTIME_SHIFT) - 1)
1249 
1250 /* Convert an incore quota expiration timestamp to an ondisk bigtime value. */
1251 static inline uint32_t xfs_dq_unix_to_bigtime(time64_t unix_seconds)
1252 {
1253 	/*
1254 	 * Round the expiration timestamp up to the nearest bigtime timestamp
1255 	 * that we can store, to give users the most time to fix problems.
1256 	 */
1257 	return ((uint64_t)unix_seconds + XFS_DQ_BIGTIME_SLACK) >>
1258 			XFS_DQ_BIGTIME_SHIFT;
1259 }
1260 
1261 /* Convert an ondisk bigtime quota expiration value to an incore timestamp. */
1262 static inline time64_t xfs_dq_bigtime_to_unix(uint32_t ondisk_seconds)
1263 {
1264 	return (time64_t)ondisk_seconds << XFS_DQ_BIGTIME_SHIFT;
1265 }
1266 
1267 /*
1268  * Default quota grace periods, ranging from zero (use the compiled defaults)
1269  * to ~136 years.  These are applied to a non-root dquot that has exceeded
1270  * either limit.
1271  */
1272 #define XFS_DQ_GRACE_MIN		((int64_t)0)
1273 #define XFS_DQ_GRACE_MAX		((int64_t)U32_MAX)
1274 
1275 /*
1276  * This is the main portion of the on-disk representation of quota information
1277  * for a user.  We pad this with some more expansion room to construct the on
1278  * disk structure.
1279  */
1280 struct xfs_disk_dquot {
1281 	__be16		d_magic;	/* dquot magic = XFS_DQUOT_MAGIC */
1282 	__u8		d_version;	/* dquot version */
1283 	__u8		d_type;		/* XFS_DQTYPE_USER/PROJ/GROUP */
1284 	__be32		d_id;		/* user,project,group id */
1285 	__be64		d_blk_hardlimit;/* absolute limit on disk blks */
1286 	__be64		d_blk_softlimit;/* preferred limit on disk blks */
1287 	__be64		d_ino_hardlimit;/* maximum # allocated inodes */
1288 	__be64		d_ino_softlimit;/* preferred inode limit */
1289 	__be64		d_bcount;	/* disk blocks owned by the user */
1290 	__be64		d_icount;	/* inodes owned by the user */
1291 	__be32		d_itimer;	/* zero if within inode limits if not,
1292 					   this is when we refuse service */
1293 	__be32		d_btimer;	/* similar to above; for disk blocks */
1294 	__be16		d_iwarns;	/* warnings issued wrt num inodes */
1295 	__be16		d_bwarns;	/* warnings issued wrt disk blocks */
1296 	__be32		d_pad0;		/* 64 bit align */
1297 	__be64		d_rtb_hardlimit;/* absolute limit on realtime blks */
1298 	__be64		d_rtb_softlimit;/* preferred limit on RT disk blks */
1299 	__be64		d_rtbcount;	/* realtime blocks owned */
1300 	__be32		d_rtbtimer;	/* similar to above; for RT disk blocks */
1301 	__be16		d_rtbwarns;	/* warnings issued wrt RT disk blocks */
1302 	__be16		d_pad;
1303 };
1304 
1305 /*
1306  * This is what goes on disk. This is separated from the xfs_disk_dquot because
1307  * carrying the unnecessary padding would be a waste of memory.
1308  */
1309 struct xfs_dqblk {
1310 	struct xfs_disk_dquot	dd_diskdq; /* portion living incore as well */
1311 	char			dd_fill[4];/* filling for posterity */
1312 
1313 	/*
1314 	 * These two are only present on filesystems with the CRC bits set.
1315 	 */
1316 	__be32		  dd_crc;	/* checksum */
1317 	__be64		  dd_lsn;	/* last modification in log */
1318 	uuid_t		  dd_uuid;	/* location information */
1319 };
1320 
1321 #define XFS_DQUOT_CRC_OFF	offsetof(struct xfs_dqblk, dd_crc)
1322 
1323 /*
1324  * This defines the unit of allocation of dquots.
1325  *
1326  * Currently, it is just one file system block, and a 4K blk contains 30
1327  * (136 * 30 = 4080) dquots. It's probably not worth trying to make
1328  * this more dynamic.
1329  *
1330  * However, if this number is changed, we have to make sure that we don't
1331  * implicitly assume that we do allocations in chunks of a single filesystem
1332  * block in the dquot/xqm code.
1333  *
1334  * This is part of the ondisk format because the structure size is not a power
1335  * of two, which leaves slack at the end of the disk block.
1336  */
1337 #define XFS_DQUOT_CLUSTER_SIZE_FSB	(xfs_filblks_t)1
1338 
1339 /*
1340  * Remote symlink format and access functions.
1341  */
1342 #define XFS_SYMLINK_MAGIC	0x58534c4d	/* XSLM */
1343 
1344 struct xfs_dsymlink_hdr {
1345 	__be32	sl_magic;
1346 	__be32	sl_offset;
1347 	__be32	sl_bytes;
1348 	__be32	sl_crc;
1349 	uuid_t	sl_uuid;
1350 	__be64	sl_owner;
1351 	__be64	sl_blkno;
1352 	__be64	sl_lsn;
1353 };
1354 
1355 #define XFS_SYMLINK_CRC_OFF	offsetof(struct xfs_dsymlink_hdr, sl_crc)
1356 
1357 #define XFS_SYMLINK_MAXLEN	1024
1358 /*
1359  * The maximum pathlen is 1024 bytes. Since the minimum file system
1360  * blocksize is 512 bytes, we can get a max of 3 extents back from
1361  * bmapi when crc headers are taken into account.
1362  */
1363 #define XFS_SYMLINK_MAPS 3
1364 
1365 #define XFS_SYMLINK_BUF_SPACE(mp, bufsize)	\
1366 	((bufsize) - (xfs_has_crc((mp)) ? \
1367 			sizeof(struct xfs_dsymlink_hdr) : 0))
1368 
1369 
1370 /*
1371  * Allocation Btree format definitions
1372  *
1373  * There are two on-disk btrees, one sorted by blockno and one sorted
1374  * by blockcount and blockno.  All blocks look the same to make the code
1375  * simpler; if we have time later, we'll make the optimizations.
1376  */
1377 #define	XFS_ABTB_MAGIC		0x41425442	/* 'ABTB' for bno tree */
1378 #define	XFS_ABTB_CRC_MAGIC	0x41423342	/* 'AB3B' */
1379 #define	XFS_ABTC_MAGIC		0x41425443	/* 'ABTC' for cnt tree */
1380 #define	XFS_ABTC_CRC_MAGIC	0x41423343	/* 'AB3C' */
1381 
1382 /*
1383  * Data record/key structure
1384  */
1385 typedef struct xfs_alloc_rec {
1386 	__be32		ar_startblock;	/* starting block number */
1387 	__be32		ar_blockcount;	/* count of free blocks */
1388 } xfs_alloc_rec_t, xfs_alloc_key_t;
1389 
1390 typedef struct xfs_alloc_rec_incore {
1391 	xfs_agblock_t	ar_startblock;	/* starting block number */
1392 	xfs_extlen_t	ar_blockcount;	/* count of free blocks */
1393 } xfs_alloc_rec_incore_t;
1394 
1395 /* btree pointer type */
1396 typedef __be32 xfs_alloc_ptr_t;
1397 
1398 /*
1399  * Block numbers in the AG:
1400  * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
1401  */
1402 #define	XFS_BNO_BLOCK(mp)	((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
1403 #define	XFS_CNT_BLOCK(mp)	((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
1404 
1405 
1406 /*
1407  * Inode Allocation Btree format definitions
1408  *
1409  * There is a btree for the inode map per allocation group.
1410  */
1411 #define	XFS_IBT_MAGIC		0x49414254	/* 'IABT' */
1412 #define	XFS_IBT_CRC_MAGIC	0x49414233	/* 'IAB3' */
1413 #define	XFS_FIBT_MAGIC		0x46494254	/* 'FIBT' */
1414 #define	XFS_FIBT_CRC_MAGIC	0x46494233	/* 'FIB3' */
1415 
1416 typedef uint64_t	xfs_inofree_t;
1417 #define	XFS_INODES_PER_CHUNK		(NBBY * sizeof(xfs_inofree_t))
1418 #define	XFS_INODES_PER_CHUNK_LOG	(XFS_NBBYLOG + 3)
1419 #define	XFS_INOBT_ALL_FREE		((xfs_inofree_t)-1)
1420 #define	XFS_INOBT_MASK(i)		((xfs_inofree_t)1 << (i))
1421 
1422 #define XFS_INOBT_HOLEMASK_FULL		0	/* holemask for full chunk */
1423 #define XFS_INOBT_HOLEMASK_BITS		(NBBY * sizeof(uint16_t))
1424 #define XFS_INODES_PER_HOLEMASK_BIT	\
1425 	(XFS_INODES_PER_CHUNK / (NBBY * sizeof(uint16_t)))
1426 
1427 static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
1428 {
1429 	return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
1430 }
1431 
1432 /*
1433  * The on-disk inode record structure has two formats. The original "full"
1434  * format uses a 4-byte freecount. The "sparse" format uses a 1-byte freecount
1435  * and replaces the 3 high-order freecount bytes wth the holemask and inode
1436  * count.
1437  *
1438  * The holemask of the sparse record format allows an inode chunk to have holes
1439  * that refer to blocks not owned by the inode record. This facilitates inode
1440  * allocation in the event of severe free space fragmentation.
1441  */
1442 typedef struct xfs_inobt_rec {
1443 	__be32		ir_startino;	/* starting inode number */
1444 	union {
1445 		struct {
1446 			__be32	ir_freecount;	/* count of free inodes */
1447 		} f;
1448 		struct {
1449 			__be16	ir_holemask;/* hole mask for sparse chunks */
1450 			__u8	ir_count;	/* total inode count */
1451 			__u8	ir_freecount;	/* count of free inodes */
1452 		} sp;
1453 	} ir_u;
1454 	__be64		ir_free;	/* free inode mask */
1455 } xfs_inobt_rec_t;
1456 
1457 typedef struct xfs_inobt_rec_incore {
1458 	xfs_agino_t	ir_startino;	/* starting inode number */
1459 	uint16_t	ir_holemask;	/* hole mask for sparse chunks */
1460 	uint8_t		ir_count;	/* total inode count */
1461 	uint8_t		ir_freecount;	/* count of free inodes (set bits) */
1462 	xfs_inofree_t	ir_free;	/* free inode mask */
1463 } xfs_inobt_rec_incore_t;
1464 
1465 static inline bool xfs_inobt_issparse(uint16_t holemask)
1466 {
1467 	/* non-zero holemask represents a sparse rec. */
1468 	return holemask;
1469 }
1470 
1471 /*
1472  * Key structure
1473  */
1474 typedef struct xfs_inobt_key {
1475 	__be32		ir_startino;	/* starting inode number */
1476 } xfs_inobt_key_t;
1477 
1478 /* btree pointer type */
1479 typedef __be32 xfs_inobt_ptr_t;
1480 
1481 /*
1482  * block numbers in the AG.
1483  */
1484 #define	XFS_IBT_BLOCK(mp)		((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))
1485 #define	XFS_FIBT_BLOCK(mp)		((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
1486 
1487 /*
1488  * Reverse mapping btree format definitions
1489  *
1490  * There is a btree for the reverse map per allocation group
1491  */
1492 #define	XFS_RMAP_CRC_MAGIC	0x524d4233	/* 'RMB3' */
1493 
1494 /*
1495  * Ownership info for an extent.  This is used to create reverse-mapping
1496  * entries.
1497  */
1498 #define XFS_OWNER_INFO_ATTR_FORK	(1 << 0)
1499 #define XFS_OWNER_INFO_BMBT_BLOCK	(1 << 1)
1500 struct xfs_owner_info {
1501 	uint64_t		oi_owner;
1502 	xfs_fileoff_t		oi_offset;
1503 	unsigned int		oi_flags;
1504 };
1505 
1506 /*
1507  * Special owner types.
1508  *
1509  * Seeing as we only support up to 8EB, we have the upper bit of the owner field
1510  * to tell us we have a special owner value. We use these for static metadata
1511  * allocated at mkfs/growfs time, as well as for freespace management metadata.
1512  */
1513 #define XFS_RMAP_OWN_NULL	(-1ULL)	/* No owner, for growfs */
1514 #define XFS_RMAP_OWN_UNKNOWN	(-2ULL)	/* Unknown owner, for EFI recovery */
1515 #define XFS_RMAP_OWN_FS		(-3ULL)	/* static fs metadata */
1516 #define XFS_RMAP_OWN_LOG	(-4ULL)	/* static fs metadata */
1517 #define XFS_RMAP_OWN_AG		(-5ULL)	/* AG freespace btree blocks */
1518 #define XFS_RMAP_OWN_INOBT	(-6ULL)	/* Inode btree blocks */
1519 #define XFS_RMAP_OWN_INODES	(-7ULL)	/* Inode chunk */
1520 #define XFS_RMAP_OWN_REFC	(-8ULL) /* refcount tree */
1521 #define XFS_RMAP_OWN_COW	(-9ULL) /* cow allocations */
1522 #define XFS_RMAP_OWN_MIN	(-10ULL) /* guard */
1523 
1524 #define XFS_RMAP_NON_INODE_OWNER(owner)	(!!((owner) & (1ULL << 63)))
1525 
1526 /*
1527  * Data record structure
1528  */
1529 struct xfs_rmap_rec {
1530 	__be32		rm_startblock;	/* extent start block */
1531 	__be32		rm_blockcount;	/* extent length */
1532 	__be64		rm_owner;	/* extent owner */
1533 	__be64		rm_offset;	/* offset within the owner */
1534 };
1535 
1536 /*
1537  * rmap btree record
1538  *  rm_offset:63 is the attribute fork flag
1539  *  rm_offset:62 is the bmbt block flag
1540  *  rm_offset:61 is the unwritten extent flag (same as l0:63 in bmbt)
1541  *  rm_offset:54-60 aren't used and should be zero
1542  *  rm_offset:0-53 is the block offset within the inode
1543  */
1544 #define XFS_RMAP_OFF_ATTR_FORK	((uint64_t)1ULL << 63)
1545 #define XFS_RMAP_OFF_BMBT_BLOCK	((uint64_t)1ULL << 62)
1546 #define XFS_RMAP_OFF_UNWRITTEN	((uint64_t)1ULL << 61)
1547 
1548 #define XFS_RMAP_LEN_MAX	((uint32_t)~0U)
1549 #define XFS_RMAP_OFF_FLAGS	(XFS_RMAP_OFF_ATTR_FORK | \
1550 				 XFS_RMAP_OFF_BMBT_BLOCK | \
1551 				 XFS_RMAP_OFF_UNWRITTEN)
1552 #define XFS_RMAP_OFF_MASK	((uint64_t)0x3FFFFFFFFFFFFFULL)
1553 
1554 #define XFS_RMAP_OFF(off)		((off) & XFS_RMAP_OFF_MASK)
1555 
1556 #define XFS_RMAP_IS_BMBT_BLOCK(off)	(!!((off) & XFS_RMAP_OFF_BMBT_BLOCK))
1557 #define XFS_RMAP_IS_ATTR_FORK(off)	(!!((off) & XFS_RMAP_OFF_ATTR_FORK))
1558 #define XFS_RMAP_IS_UNWRITTEN(len)	(!!((off) & XFS_RMAP_OFF_UNWRITTEN))
1559 
1560 #define RMAPBT_STARTBLOCK_BITLEN	32
1561 #define RMAPBT_BLOCKCOUNT_BITLEN	32
1562 #define RMAPBT_OWNER_BITLEN		64
1563 #define RMAPBT_ATTRFLAG_BITLEN		1
1564 #define RMAPBT_BMBTFLAG_BITLEN		1
1565 #define RMAPBT_EXNTFLAG_BITLEN		1
1566 #define RMAPBT_UNUSED_OFFSET_BITLEN	7
1567 #define RMAPBT_OFFSET_BITLEN		54
1568 
1569 /*
1570  * Key structure
1571  *
1572  * We don't use the length for lookups
1573  */
1574 struct xfs_rmap_key {
1575 	__be32		rm_startblock;	/* extent start block */
1576 	__be64		rm_owner;	/* extent owner */
1577 	__be64		rm_offset;	/* offset within the owner */
1578 } __attribute__((packed));
1579 
1580 /* btree pointer type */
1581 typedef __be32 xfs_rmap_ptr_t;
1582 
1583 #define	XFS_RMAP_BLOCK(mp) \
1584 	(xfs_has_finobt(((mp))) ? \
1585 	 XFS_FIBT_BLOCK(mp) + 1 : \
1586 	 XFS_IBT_BLOCK(mp) + 1)
1587 
1588 /*
1589  * Reference Count Btree format definitions
1590  *
1591  */
1592 #define	XFS_REFC_CRC_MAGIC	0x52334643	/* 'R3FC' */
1593 
1594 unsigned int xfs_refc_block(struct xfs_mount *mp);
1595 
1596 /*
1597  * Data record/key structure
1598  *
1599  * Each record associates a range of physical blocks (starting at
1600  * rc_startblock and ending rc_blockcount blocks later) with a reference
1601  * count (rc_refcount).  Extents that are being used to stage a copy on
1602  * write (CoW) operation are recorded in the refcount btree with a
1603  * refcount of 1.  All other records must have a refcount > 1 and must
1604  * track an extent mapped only by file data forks.
1605  *
1606  * Extents with a single owner (attributes, metadata, non-shared file
1607  * data) are not tracked here.  Free space is also not tracked here.
1608  * This is consistent with pre-reflink XFS.
1609  */
1610 
1611 /*
1612  * Extents that are being used to stage a copy on write are stored
1613  * in the refcount btree with a refcount of 1 and the upper bit set
1614  * on the startblock.  This speeds up mount time deletion of stale
1615  * staging extents because they're all at the right side of the tree.
1616  */
1617 #define XFS_REFC_COWFLAG		(1U << 31)
1618 #define REFCNTBT_COWFLAG_BITLEN		1
1619 #define REFCNTBT_AGBLOCK_BITLEN		31
1620 
1621 struct xfs_refcount_rec {
1622 	__be32		rc_startblock;	/* starting block number */
1623 	__be32		rc_blockcount;	/* count of blocks */
1624 	__be32		rc_refcount;	/* number of inodes linked here */
1625 };
1626 
1627 struct xfs_refcount_key {
1628 	__be32		rc_startblock;	/* starting block number */
1629 };
1630 
1631 #define MAXREFCOUNT	((xfs_nlink_t)~0U)
1632 #define MAXREFCEXTLEN	((xfs_extlen_t)~0U)
1633 
1634 /* btree pointer type */
1635 typedef __be32 xfs_refcount_ptr_t;
1636 
1637 
1638 /*
1639  * BMAP Btree format definitions
1640  *
1641  * This includes both the root block definition that sits inside an inode fork
1642  * and the record/pointer formats for the leaf/node in the blocks.
1643  */
1644 #define XFS_BMAP_MAGIC		0x424d4150	/* 'BMAP' */
1645 #define XFS_BMAP_CRC_MAGIC	0x424d4133	/* 'BMA3' */
1646 
1647 /*
1648  * Bmap root header, on-disk form only.
1649  */
1650 typedef struct xfs_bmdr_block {
1651 	__be16		bb_level;	/* 0 is a leaf */
1652 	__be16		bb_numrecs;	/* current # of data records */
1653 } xfs_bmdr_block_t;
1654 
1655 /*
1656  * Bmap btree record and extent descriptor.
1657  *  l0:63 is an extent flag (value 1 indicates non-normal).
1658  *  l0:9-62 are startoff.
1659  *  l0:0-8 and l1:21-63 are startblock.
1660  *  l1:0-20 are blockcount.
1661  */
1662 #define BMBT_EXNTFLAG_BITLEN	1
1663 #define BMBT_STARTOFF_BITLEN	54
1664 #define BMBT_STARTBLOCK_BITLEN	52
1665 #define BMBT_BLOCKCOUNT_BITLEN	21
1666 
1667 #define BMBT_STARTOFF_MASK	((1ULL << BMBT_STARTOFF_BITLEN) - 1)
1668 #define BMBT_BLOCKCOUNT_MASK	((1ULL << BMBT_BLOCKCOUNT_BITLEN) - 1)
1669 
1670 #define XFS_MAX_BMBT_EXTLEN	((xfs_extlen_t)(BMBT_BLOCKCOUNT_MASK))
1671 
1672 /*
1673  * bmbt records have a file offset (block) field that is 54 bits wide, so this
1674  * is the largest xfs_fileoff_t that we ever expect to see.
1675  */
1676 #define XFS_MAX_FILEOFF		(BMBT_STARTOFF_MASK + BMBT_BLOCKCOUNT_MASK)
1677 
1678 typedef struct xfs_bmbt_rec {
1679 	__be64			l0, l1;
1680 } xfs_bmbt_rec_t;
1681 
1682 typedef uint64_t	xfs_bmbt_rec_base_t;	/* use this for casts */
1683 typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
1684 
1685 /*
1686  * Values and macros for delayed-allocation startblock fields.
1687  */
1688 #define STARTBLOCKVALBITS	17
1689 #define STARTBLOCKMASKBITS	(15 + 20)
1690 #define STARTBLOCKMASK		\
1691 	(((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
1692 
1693 static inline int isnullstartblock(xfs_fsblock_t x)
1694 {
1695 	return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
1696 }
1697 
1698 static inline xfs_fsblock_t nullstartblock(int k)
1699 {
1700 	ASSERT(k < (1 << STARTBLOCKVALBITS));
1701 	return STARTBLOCKMASK | (k);
1702 }
1703 
1704 static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
1705 {
1706 	return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
1707 }
1708 
1709 /*
1710  * Key structure for non-leaf levels of the tree.
1711  */
1712 typedef struct xfs_bmbt_key {
1713 	__be64		br_startoff;	/* starting file offset */
1714 } xfs_bmbt_key_t, xfs_bmdr_key_t;
1715 
1716 /* btree pointer type */
1717 typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
1718 
1719 
1720 /*
1721  * Generic Btree block format definitions
1722  *
1723  * This is a combination of the actual format used on disk for short and long
1724  * format btrees.  The first three fields are shared by both format, but the
1725  * pointers are different and should be used with care.
1726  *
1727  * To get the size of the actual short or long form headers please use the size
1728  * macros below.  Never use sizeof(xfs_btree_block).
1729  *
1730  * The blkno, crc, lsn, owner and uuid fields are only available in filesystems
1731  * with the crc feature bit, and all accesses to them must be conditional on
1732  * that flag.
1733  */
1734 /* short form block header */
1735 struct xfs_btree_block_shdr {
1736 	__be32		bb_leftsib;
1737 	__be32		bb_rightsib;
1738 
1739 	__be64		bb_blkno;
1740 	__be64		bb_lsn;
1741 	uuid_t		bb_uuid;
1742 	__be32		bb_owner;
1743 	__le32		bb_crc;
1744 };
1745 
1746 /* long form block header */
1747 struct xfs_btree_block_lhdr {
1748 	__be64		bb_leftsib;
1749 	__be64		bb_rightsib;
1750 
1751 	__be64		bb_blkno;
1752 	__be64		bb_lsn;
1753 	uuid_t		bb_uuid;
1754 	__be64		bb_owner;
1755 	__le32		bb_crc;
1756 	__be32		bb_pad; /* padding for alignment */
1757 };
1758 
1759 struct xfs_btree_block {
1760 	__be32		bb_magic;	/* magic number for block type */
1761 	__be16		bb_level;	/* 0 is a leaf */
1762 	__be16		bb_numrecs;	/* current # of data records */
1763 	union {
1764 		struct xfs_btree_block_shdr s;
1765 		struct xfs_btree_block_lhdr l;
1766 	} bb_u;				/* rest */
1767 };
1768 
1769 /* size of a short form block */
1770 #define XFS_BTREE_SBLOCK_LEN \
1771 	(offsetof(struct xfs_btree_block, bb_u) + \
1772 	 offsetof(struct xfs_btree_block_shdr, bb_blkno))
1773 /* size of a long form block */
1774 #define XFS_BTREE_LBLOCK_LEN \
1775 	(offsetof(struct xfs_btree_block, bb_u) + \
1776 	 offsetof(struct xfs_btree_block_lhdr, bb_blkno))
1777 
1778 /* sizes of CRC enabled btree blocks */
1779 #define XFS_BTREE_SBLOCK_CRC_LEN \
1780 	(offsetof(struct xfs_btree_block, bb_u) + \
1781 	 sizeof(struct xfs_btree_block_shdr))
1782 #define XFS_BTREE_LBLOCK_CRC_LEN \
1783 	(offsetof(struct xfs_btree_block, bb_u) + \
1784 	 sizeof(struct xfs_btree_block_lhdr))
1785 
1786 #define XFS_BTREE_SBLOCK_CRC_OFF \
1787 	offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
1788 #define XFS_BTREE_LBLOCK_CRC_OFF \
1789 	offsetof(struct xfs_btree_block, bb_u.l.bb_crc)
1790 
1791 /*
1792  * On-disk XFS access control list structure.
1793  */
1794 struct xfs_acl_entry {
1795 	__be32	ae_tag;
1796 	__be32	ae_id;
1797 	__be16	ae_perm;
1798 	__be16	ae_pad;		/* fill the implicit hole in the structure */
1799 };
1800 
1801 struct xfs_acl {
1802 	__be32			acl_cnt;
1803 	struct xfs_acl_entry	acl_entry[];
1804 };
1805 
1806 /*
1807  * The number of ACL entries allowed is defined by the on-disk format.
1808  * For v4 superblocks, that is limited to 25 entries. For v5 superblocks, it is
1809  * limited only by the maximum size of the xattr that stores the information.
1810  */
1811 #define XFS_ACL_MAX_ENTRIES(mp)	\
1812 	(xfs_has_crc(mp) \
1813 		?  (XFS_XATTR_SIZE_MAX - sizeof(struct xfs_acl)) / \
1814 						sizeof(struct xfs_acl_entry) \
1815 		: 25)
1816 
1817 #define XFS_ACL_SIZE(cnt) \
1818 	(sizeof(struct xfs_acl) + \
1819 		sizeof(struct xfs_acl_entry) * cnt)
1820 
1821 #define XFS_ACL_MAX_SIZE(mp) \
1822 	XFS_ACL_SIZE(XFS_ACL_MAX_ENTRIES((mp)))
1823 
1824 
1825 /* On-disk XFS extended attribute names */
1826 #define SGI_ACL_FILE		"SGI_ACL_FILE"
1827 #define SGI_ACL_DEFAULT		"SGI_ACL_DEFAULT"
1828 #define SGI_ACL_FILE_SIZE	(sizeof(SGI_ACL_FILE)-1)
1829 #define SGI_ACL_DEFAULT_SIZE	(sizeof(SGI_ACL_DEFAULT)-1)
1830 
1831 #endif /* __XFS_FORMAT_H__ */
1832