1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#ifndef	__XFS_INODE_FORK_H__
7#define	__XFS_INODE_FORK_H__
8
9struct xfs_inode_log_item;
10struct xfs_dinode;
11
12/*
13 * File incore extent information, present for each of data & attr forks.
14 */
15struct xfs_ifork {
16	int64_t			if_bytes;	/* bytes in if_u1 */
17	struct xfs_btree_block	*if_broot;	/* file's incore btree root */
18	unsigned int		if_seq;		/* fork mod counter */
19	int			if_height;	/* height of the extent tree */
20	union {
21		void		*if_root;	/* extent tree root */
22		char		*if_data;	/* inline file data */
23	} if_u1;
24	xfs_extnum_t		if_nextents;	/* # of extents in this fork */
25	short			if_broot_bytes;	/* bytes allocated for root */
26	int8_t			if_format;	/* format of this fork */
27	uint8_t			if_needextents;	/* extents have not been read */
28};
29
30/*
31 * Worst-case increase in the fork extent count when we're adding a single
32 * extent to a fork and there's no possibility of splitting an existing mapping.
33 */
34#define XFS_IEXT_ADD_NOSPLIT_CNT	(1)
35
36/*
37 * Punching out an extent from the middle of an existing extent can cause the
38 * extent count to increase by 1.
39 * i.e. | Old extent | Hole | Old extent |
40 */
41#define XFS_IEXT_PUNCH_HOLE_CNT		(1)
42
43/*
44 * Adding/removing an xattr can cause XFS_DA_NODE_MAXDEPTH extents to
45 * be added. One extra extent for dabtree in case a local attr is
46 * large enough to cause a double split.  It can also cause extent
47 * count to increase proportional to the size of a remote xattr's
48 * value.
49 */
50#define XFS_IEXT_ATTR_MANIP_CNT(rmt_blks) \
51	(XFS_DA_NODE_MAXDEPTH + max(1, rmt_blks))
52
53/*
54 * A write to a sub-interval of an existing unwritten extent causes the original
55 * extent to be split into 3 extents
56 * i.e. | Unwritten | Real | Unwritten |
57 * Hence extent count can increase by 2.
58 */
59#define XFS_IEXT_WRITE_UNWRITTEN_CNT	(2)
60
61
62/*
63 * Moving an extent to data fork can cause a sub-interval of an existing extent
64 * to be unmapped. This will increase extent count by 1. Mapping in the new
65 * extent can increase the extent count by 1 again i.e.
66 * | Old extent | New extent | Old extent |
67 * Hence number of extents increases by 2.
68 */
69#define XFS_IEXT_REFLINK_END_COW_CNT	(2)
70
71/*
72 * Removing an initial range of source/donor file's extent and adding a new
73 * extent (from donor/source file) in its place will cause extent count to
74 * increase by 1.
75 */
76#define XFS_IEXT_SWAP_RMAP_CNT		(1)
77
78/*
79 * Fork handling.
80 */
81#define XFS_IFORK_MAXEXT(ip, w) \
82	(xfs_inode_fork_size(ip, w) / sizeof(xfs_bmbt_rec_t))
83
84static inline bool xfs_ifork_has_extents(struct xfs_ifork *ifp)
85{
86	return ifp->if_format == XFS_DINODE_FMT_EXTENTS ||
87		ifp->if_format == XFS_DINODE_FMT_BTREE;
88}
89
90static inline xfs_extnum_t xfs_ifork_nextents(struct xfs_ifork *ifp)
91{
92	if (!ifp)
93		return 0;
94	return ifp->if_nextents;
95}
96
97static inline int8_t xfs_ifork_format(struct xfs_ifork *ifp)
98{
99	if (!ifp)
100		return XFS_DINODE_FMT_EXTENTS;
101	return ifp->if_format;
102}
103
104static inline xfs_extnum_t xfs_iext_max_nextents(bool has_large_extent_counts,
105				int whichfork)
106{
107	switch (whichfork) {
108	case XFS_DATA_FORK:
109	case XFS_COW_FORK:
110		if (has_large_extent_counts)
111			return XFS_MAX_EXTCNT_DATA_FORK_LARGE;
112		return XFS_MAX_EXTCNT_DATA_FORK_SMALL;
113
114	case XFS_ATTR_FORK:
115		if (has_large_extent_counts)
116			return XFS_MAX_EXTCNT_ATTR_FORK_LARGE;
117		return XFS_MAX_EXTCNT_ATTR_FORK_SMALL;
118
119	default:
120		ASSERT(0);
121		return 0;
122	}
123}
124
125static inline xfs_extnum_t
126xfs_dfork_data_extents(
127	struct xfs_dinode	*dip)
128{
129	if (xfs_dinode_has_large_extent_counts(dip))
130		return be64_to_cpu(dip->di_big_nextents);
131
132	return be32_to_cpu(dip->di_nextents);
133}
134
135static inline xfs_extnum_t
136xfs_dfork_attr_extents(
137	struct xfs_dinode	*dip)
138{
139	if (xfs_dinode_has_large_extent_counts(dip))
140		return be32_to_cpu(dip->di_big_anextents);
141
142	return be16_to_cpu(dip->di_anextents);
143}
144
145static inline xfs_extnum_t
146xfs_dfork_nextents(
147	struct xfs_dinode	*dip,
148	int			whichfork)
149{
150	switch (whichfork) {
151	case XFS_DATA_FORK:
152		return xfs_dfork_data_extents(dip);
153	case XFS_ATTR_FORK:
154		return xfs_dfork_attr_extents(dip);
155	default:
156		ASSERT(0);
157		break;
158	}
159
160	return 0;
161}
162
163void xfs_ifork_zap_attr(struct xfs_inode *ip);
164void xfs_ifork_init_attr(struct xfs_inode *ip, enum xfs_dinode_fmt format,
165		xfs_extnum_t nextents);
166struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
167
168int		xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
169int		xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
170void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
171				struct xfs_inode_log_item *, int);
172void		xfs_idestroy_fork(struct xfs_ifork *ifp);
173void		xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
174				int whichfork);
175void		xfs_iroot_realloc(struct xfs_inode *, int, int);
176int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
177int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
178				  int);
179void		xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
180				const void *data, int64_t size);
181
182xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
183void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
184			struct xfs_bmbt_irec *, int);
185void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
186			int);
187void		xfs_iext_destroy(struct xfs_ifork *);
188
189bool		xfs_iext_lookup_extent(struct xfs_inode *ip,
190			struct xfs_ifork *ifp, xfs_fileoff_t bno,
191			struct xfs_iext_cursor *cur,
192			struct xfs_bmbt_irec *gotp);
193bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,
194			struct xfs_ifork *ifp, xfs_fileoff_t *end,
195			struct xfs_iext_cursor *cur,
196			struct xfs_bmbt_irec *gotp);
197bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
198			struct xfs_iext_cursor *cur,
199			struct xfs_bmbt_irec *gotp);
200void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
201			struct xfs_iext_cursor *cur,
202			struct xfs_bmbt_irec *gotp);
203
204void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
205void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
206void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
207void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
208
209static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
210		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
211{
212	xfs_iext_next(ifp, cur);
213	return xfs_iext_get_extent(ifp, cur, gotp);
214}
215
216static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
217		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
218{
219	xfs_iext_prev(ifp, cur);
220	return xfs_iext_get_extent(ifp, cur, gotp);
221}
222
223/*
224 * Return the extent after cur in gotp without updating the cursor.
225 */
226static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
227		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
228{
229	struct xfs_iext_cursor ncur = *cur;
230
231	xfs_iext_next(ifp, &ncur);
232	return xfs_iext_get_extent(ifp, &ncur, gotp);
233}
234
235/*
236 * Return the extent before cur in gotp without updating the cursor.
237 */
238static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
239		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
240{
241	struct xfs_iext_cursor ncur = *cur;
242
243	xfs_iext_prev(ifp, &ncur);
244	return xfs_iext_get_extent(ifp, &ncur, gotp);
245}
246
247#define for_each_xfs_iext(ifp, ext, got)		\
248	for (xfs_iext_first((ifp), (ext));		\
249	     xfs_iext_get_extent((ifp), (ext), (got));	\
250	     xfs_iext_next((ifp), (ext)))
251
252extern struct kmem_cache	*xfs_ifork_cache;
253
254extern void xfs_ifork_init_cow(struct xfs_inode *ip);
255
256int xfs_ifork_verify_local_data(struct xfs_inode *ip);
257int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
258int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
259		int nr_to_add);
260int xfs_iext_count_upgrade(struct xfs_trans *tp, struct xfs_inode *ip,
261		uint nr_to_add);
262
263/* returns true if the fork has extents but they are not read in yet. */
264static inline bool xfs_need_iread_extents(const struct xfs_ifork *ifp)
265{
266	/* see xfs_iformat_{data,attr}_fork() for needextents semantics */
267	return smp_load_acquire(&ifp->if_needextents) != 0;
268}
269
270#endif	/* __XFS_INODE_FORK_H__ */
271