xref: /openbmc/linux/fs/xfs/libxfs/xfs_inode_fork.h (revision be2b81b5)
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 #define XFS_IFORK_MAXEXT(ip, w) \
81 	(xfs_inode_fork_size(ip, w) / sizeof(xfs_bmbt_rec_t))
82 
83 static inline bool xfs_ifork_has_extents(struct xfs_ifork *ifp)
84 {
85 	return ifp->if_format == XFS_DINODE_FMT_EXTENTS ||
86 		ifp->if_format == XFS_DINODE_FMT_BTREE;
87 }
88 
89 static inline xfs_extnum_t xfs_ifork_nextents(struct xfs_ifork *ifp)
90 {
91 	if (!ifp)
92 		return 0;
93 	return ifp->if_nextents;
94 }
95 
96 static inline int8_t xfs_ifork_format(struct xfs_ifork *ifp)
97 {
98 	if (!ifp)
99 		return XFS_DINODE_FMT_EXTENTS;
100 	return ifp->if_format;
101 }
102 
103 static inline xfs_extnum_t xfs_iext_max_nextents(bool has_large_extent_counts,
104 				int whichfork)
105 {
106 	switch (whichfork) {
107 	case XFS_DATA_FORK:
108 	case XFS_COW_FORK:
109 		if (has_large_extent_counts)
110 			return XFS_MAX_EXTCNT_DATA_FORK_LARGE;
111 		return XFS_MAX_EXTCNT_DATA_FORK_SMALL;
112 
113 	case XFS_ATTR_FORK:
114 		if (has_large_extent_counts)
115 			return XFS_MAX_EXTCNT_ATTR_FORK_LARGE;
116 		return XFS_MAX_EXTCNT_ATTR_FORK_SMALL;
117 
118 	default:
119 		ASSERT(0);
120 		return 0;
121 	}
122 }
123 
124 static inline xfs_extnum_t
125 xfs_dfork_data_extents(
126 	struct xfs_dinode	*dip)
127 {
128 	if (xfs_dinode_has_large_extent_counts(dip))
129 		return be64_to_cpu(dip->di_big_nextents);
130 
131 	return be32_to_cpu(dip->di_nextents);
132 }
133 
134 static inline xfs_extnum_t
135 xfs_dfork_attr_extents(
136 	struct xfs_dinode	*dip)
137 {
138 	if (xfs_dinode_has_large_extent_counts(dip))
139 		return be32_to_cpu(dip->di_big_anextents);
140 
141 	return be16_to_cpu(dip->di_anextents);
142 }
143 
144 static inline xfs_extnum_t
145 xfs_dfork_nextents(
146 	struct xfs_dinode	*dip,
147 	int			whichfork)
148 {
149 	switch (whichfork) {
150 	case XFS_DATA_FORK:
151 		return xfs_dfork_data_extents(dip);
152 	case XFS_ATTR_FORK:
153 		return xfs_dfork_attr_extents(dip);
154 	default:
155 		ASSERT(0);
156 		break;
157 	}
158 
159 	return 0;
160 }
161 
162 void xfs_ifork_zap_attr(struct xfs_inode *ip);
163 void xfs_ifork_init_attr(struct xfs_inode *ip, enum xfs_dinode_fmt format,
164 		xfs_extnum_t nextents);
165 struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
166 
167 int		xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
168 int		xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
169 void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
170 				struct xfs_inode_log_item *, int);
171 void		xfs_idestroy_fork(struct xfs_ifork *ifp);
172 void		xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
173 				int whichfork);
174 void		xfs_iroot_realloc(struct xfs_inode *, int, int);
175 int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
176 int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
177 				  int);
178 void		xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
179 				const void *data, int64_t size);
180 
181 xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
182 void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
183 			struct xfs_bmbt_irec *, int);
184 void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
185 			int);
186 void		xfs_iext_destroy(struct xfs_ifork *);
187 
188 bool		xfs_iext_lookup_extent(struct xfs_inode *ip,
189 			struct xfs_ifork *ifp, xfs_fileoff_t bno,
190 			struct xfs_iext_cursor *cur,
191 			struct xfs_bmbt_irec *gotp);
192 bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,
193 			struct xfs_ifork *ifp, xfs_fileoff_t *end,
194 			struct xfs_iext_cursor *cur,
195 			struct xfs_bmbt_irec *gotp);
196 bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
197 			struct xfs_iext_cursor *cur,
198 			struct xfs_bmbt_irec *gotp);
199 void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
200 			struct xfs_iext_cursor *cur,
201 			struct xfs_bmbt_irec *gotp);
202 
203 void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
204 void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
205 void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
206 void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
207 
208 static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
209 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
210 {
211 	xfs_iext_next(ifp, cur);
212 	return xfs_iext_get_extent(ifp, cur, gotp);
213 }
214 
215 static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
216 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
217 {
218 	xfs_iext_prev(ifp, cur);
219 	return xfs_iext_get_extent(ifp, cur, gotp);
220 }
221 
222 /*
223  * Return the extent after cur in gotp without updating the cursor.
224  */
225 static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
226 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
227 {
228 	struct xfs_iext_cursor ncur = *cur;
229 
230 	xfs_iext_next(ifp, &ncur);
231 	return xfs_iext_get_extent(ifp, &ncur, gotp);
232 }
233 
234 /*
235  * Return the extent before cur in gotp without updating the cursor.
236  */
237 static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
238 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
239 {
240 	struct xfs_iext_cursor ncur = *cur;
241 
242 	xfs_iext_prev(ifp, &ncur);
243 	return xfs_iext_get_extent(ifp, &ncur, gotp);
244 }
245 
246 #define for_each_xfs_iext(ifp, ext, got)		\
247 	for (xfs_iext_first((ifp), (ext));		\
248 	     xfs_iext_get_extent((ifp), (ext), (got));	\
249 	     xfs_iext_next((ifp), (ext)))
250 
251 extern struct kmem_cache	*xfs_ifork_cache;
252 
253 extern void xfs_ifork_init_cow(struct xfs_inode *ip);
254 
255 int xfs_ifork_verify_local_data(struct xfs_inode *ip);
256 int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
257 int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
258 		int nr_to_add);
259 int xfs_iext_count_upgrade(struct xfs_trans *tp, struct xfs_inode *ip,
260 		uint nr_to_add);
261 
262 /* returns true if the fork has extents but they are not read in yet. */
263 static inline bool xfs_need_iread_extents(struct xfs_ifork *ifp)
264 {
265 	return ifp->if_format == XFS_DINODE_FMT_BTREE && ifp->if_height == 0;
266 }
267 
268 #endif	/* __XFS_INODE_FORK_H__ */
269