xref: /openbmc/linux/fs/xfs/libxfs/xfs_inode_fork.h (revision da1d9caf)
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 
9 struct xfs_inode_log_item;
10 struct xfs_dinode;
11 
12 /*
13  * File incore extent information, present for each of data & attr forks.
14  */
15 struct 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 };
28 
29 /*
30  * Worst-case increase in the fork extent count when we're adding a single
31  * extent to a fork and there's no possibility of splitting an existing mapping.
32  */
33 #define XFS_IEXT_ADD_NOSPLIT_CNT	(1)
34 
35 /*
36  * Punching out an extent from the middle of an existing extent can cause the
37  * extent count to increase by 1.
38  * i.e. | Old extent | Hole | Old extent |
39  */
40 #define XFS_IEXT_PUNCH_HOLE_CNT		(1)
41 
42 /*
43  * Adding/removing an xattr can cause XFS_DA_NODE_MAXDEPTH extents to
44  * be added. One extra extent for dabtree in case a local attr is
45  * large enough to cause a double split.  It can also cause extent
46  * count to increase proportional to the size of a remote xattr's
47  * value.
48  */
49 #define XFS_IEXT_ATTR_MANIP_CNT(rmt_blks) \
50 	(XFS_DA_NODE_MAXDEPTH + max(1, rmt_blks))
51 
52 /*
53  * A write to a sub-interval of an existing unwritten extent causes the original
54  * extent to be split into 3 extents
55  * i.e. | Unwritten | Real | Unwritten |
56  * Hence extent count can increase by 2.
57  */
58 #define XFS_IEXT_WRITE_UNWRITTEN_CNT	(2)
59 
60 
61 /*
62  * Moving an extent to data fork can cause a sub-interval of an existing extent
63  * to be unmapped. This will increase extent count by 1. Mapping in the new
64  * extent can increase the extent count by 1 again i.e.
65  * | Old extent | New extent | Old extent |
66  * Hence number of extents increases by 2.
67  */
68 #define XFS_IEXT_REFLINK_END_COW_CNT	(2)
69 
70 /*
71  * Removing an initial range of source/donor file's extent and adding a new
72  * extent (from donor/source file) in its place will cause extent count to
73  * increase by 1.
74  */
75 #define XFS_IEXT_SWAP_RMAP_CNT		(1)
76 
77 /*
78  * Fork handling.
79  */
80 
81 #define XFS_IFORK_Q(ip)			((ip)->i_forkoff != 0)
82 #define XFS_IFORK_BOFF(ip)		((int)((ip)->i_forkoff << 3))
83 
84 #define XFS_IFORK_PTR(ip,w)		\
85 	((w) == XFS_DATA_FORK ? \
86 		&(ip)->i_df : \
87 		((w) == XFS_ATTR_FORK ? \
88 			(ip)->i_afp : \
89 			(ip)->i_cowfp))
90 #define XFS_IFORK_DSIZE(ip) \
91 	(XFS_IFORK_Q(ip) ? XFS_IFORK_BOFF(ip) : XFS_LITINO((ip)->i_mount))
92 #define XFS_IFORK_ASIZE(ip) \
93 	(XFS_IFORK_Q(ip) ? XFS_LITINO((ip)->i_mount) - XFS_IFORK_BOFF(ip) : 0)
94 #define XFS_IFORK_SIZE(ip,w) \
95 	((w) == XFS_DATA_FORK ? \
96 		XFS_IFORK_DSIZE(ip) : \
97 		((w) == XFS_ATTR_FORK ? \
98 			XFS_IFORK_ASIZE(ip) : \
99 			0))
100 #define XFS_IFORK_MAXEXT(ip, w) \
101 	(XFS_IFORK_SIZE(ip, w) / sizeof(xfs_bmbt_rec_t))
102 
103 static inline bool xfs_ifork_has_extents(struct xfs_ifork *ifp)
104 {
105 	return ifp->if_format == XFS_DINODE_FMT_EXTENTS ||
106 		ifp->if_format == XFS_DINODE_FMT_BTREE;
107 }
108 
109 static inline xfs_extnum_t xfs_ifork_nextents(struct xfs_ifork *ifp)
110 {
111 	if (!ifp)
112 		return 0;
113 	return ifp->if_nextents;
114 }
115 
116 static inline int8_t xfs_ifork_format(struct xfs_ifork *ifp)
117 {
118 	if (!ifp)
119 		return XFS_DINODE_FMT_EXTENTS;
120 	return ifp->if_format;
121 }
122 
123 static inline xfs_extnum_t xfs_iext_max_nextents(bool has_large_extent_counts,
124 				int whichfork)
125 {
126 	switch (whichfork) {
127 	case XFS_DATA_FORK:
128 	case XFS_COW_FORK:
129 		if (has_large_extent_counts)
130 			return XFS_MAX_EXTCNT_DATA_FORK_LARGE;
131 		return XFS_MAX_EXTCNT_DATA_FORK_SMALL;
132 
133 	case XFS_ATTR_FORK:
134 		if (has_large_extent_counts)
135 			return XFS_MAX_EXTCNT_ATTR_FORK_LARGE;
136 		return XFS_MAX_EXTCNT_ATTR_FORK_SMALL;
137 
138 	default:
139 		ASSERT(0);
140 		return 0;
141 	}
142 }
143 
144 static inline xfs_extnum_t
145 xfs_dfork_data_extents(
146 	struct xfs_dinode	*dip)
147 {
148 	if (xfs_dinode_has_large_extent_counts(dip))
149 		return be64_to_cpu(dip->di_big_nextents);
150 
151 	return be32_to_cpu(dip->di_nextents);
152 }
153 
154 static inline xfs_extnum_t
155 xfs_dfork_attr_extents(
156 	struct xfs_dinode	*dip)
157 {
158 	if (xfs_dinode_has_large_extent_counts(dip))
159 		return be32_to_cpu(dip->di_big_anextents);
160 
161 	return be16_to_cpu(dip->di_anextents);
162 }
163 
164 static inline xfs_extnum_t
165 xfs_dfork_nextents(
166 	struct xfs_dinode	*dip,
167 	int			whichfork)
168 {
169 	switch (whichfork) {
170 	case XFS_DATA_FORK:
171 		return xfs_dfork_data_extents(dip);
172 	case XFS_ATTR_FORK:
173 		return xfs_dfork_attr_extents(dip);
174 	default:
175 		ASSERT(0);
176 		break;
177 	}
178 
179 	return 0;
180 }
181 
182 struct xfs_ifork *xfs_ifork_alloc(enum xfs_dinode_fmt format,
183 				xfs_extnum_t nextents);
184 struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
185 
186 int		xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
187 int		xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
188 void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
189 				struct xfs_inode_log_item *, int);
190 void		xfs_idestroy_fork(struct xfs_ifork *ifp);
191 void		xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
192 				int whichfork);
193 void		xfs_iroot_realloc(struct xfs_inode *, int, int);
194 int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
195 int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
196 				  int);
197 void		xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
198 				const void *data, int64_t size);
199 
200 xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
201 void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
202 			struct xfs_bmbt_irec *, int);
203 void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
204 			int);
205 void		xfs_iext_destroy(struct xfs_ifork *);
206 
207 bool		xfs_iext_lookup_extent(struct xfs_inode *ip,
208 			struct xfs_ifork *ifp, xfs_fileoff_t bno,
209 			struct xfs_iext_cursor *cur,
210 			struct xfs_bmbt_irec *gotp);
211 bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,
212 			struct xfs_ifork *ifp, xfs_fileoff_t *end,
213 			struct xfs_iext_cursor *cur,
214 			struct xfs_bmbt_irec *gotp);
215 bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
216 			struct xfs_iext_cursor *cur,
217 			struct xfs_bmbt_irec *gotp);
218 void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
219 			struct xfs_iext_cursor *cur,
220 			struct xfs_bmbt_irec *gotp);
221 
222 void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
223 void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
224 void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
225 void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
226 
227 static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
228 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
229 {
230 	xfs_iext_next(ifp, cur);
231 	return xfs_iext_get_extent(ifp, cur, gotp);
232 }
233 
234 static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
235 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
236 {
237 	xfs_iext_prev(ifp, cur);
238 	return xfs_iext_get_extent(ifp, cur, gotp);
239 }
240 
241 /*
242  * Return the extent after cur in gotp without updating the cursor.
243  */
244 static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
245 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
246 {
247 	struct xfs_iext_cursor ncur = *cur;
248 
249 	xfs_iext_next(ifp, &ncur);
250 	return xfs_iext_get_extent(ifp, &ncur, gotp);
251 }
252 
253 /*
254  * Return the extent before cur in gotp without updating the cursor.
255  */
256 static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
257 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
258 {
259 	struct xfs_iext_cursor ncur = *cur;
260 
261 	xfs_iext_prev(ifp, &ncur);
262 	return xfs_iext_get_extent(ifp, &ncur, gotp);
263 }
264 
265 #define for_each_xfs_iext(ifp, ext, got)		\
266 	for (xfs_iext_first((ifp), (ext));		\
267 	     xfs_iext_get_extent((ifp), (ext), (got));	\
268 	     xfs_iext_next((ifp), (ext)))
269 
270 extern struct kmem_cache	*xfs_ifork_cache;
271 
272 extern void xfs_ifork_init_cow(struct xfs_inode *ip);
273 
274 int xfs_ifork_verify_local_data(struct xfs_inode *ip);
275 int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
276 int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
277 		int nr_to_add);
278 int xfs_iext_count_upgrade(struct xfs_trans *tp, struct xfs_inode *ip,
279 		uint nr_to_add);
280 
281 /* returns true if the fork has extents but they are not read in yet. */
282 static inline bool xfs_need_iread_extents(struct xfs_ifork *ifp)
283 {
284 	return ifp->if_format == XFS_DINODE_FMT_BTREE && ifp->if_height == 0;
285 }
286 
287 #endif	/* __XFS_INODE_FORK_H__ */
288