xref: /linux/fs/xfs/libxfs/xfs_inode_fork.h (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
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 	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 
84 static 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 
90 static 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 
97 static 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 
104 static 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 
125 static inline xfs_extnum_t
126 xfs_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 
135 static inline xfs_extnum_t
136 xfs_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 
145 static inline xfs_extnum_t
146 xfs_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 
163 void xfs_ifork_zap_attr(struct xfs_inode *ip);
164 void xfs_ifork_init_attr(struct xfs_inode *ip, enum xfs_dinode_fmt format,
165 		xfs_extnum_t nextents);
166 struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
167 
168 int		xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
169 int		xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
170 void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
171 				struct xfs_inode_log_item *, int);
172 void		xfs_idestroy_fork(struct xfs_ifork *ifp);
173 void		xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
174 				int whichfork);
175 void		xfs_iroot_realloc(struct xfs_inode *, int, int);
176 int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
177 int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
178 				  int);
179 void		xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
180 				const void *data, int64_t size);
181 
182 xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
183 void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
184 			struct xfs_bmbt_irec *, int);
185 void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
186 			int);
187 void		xfs_iext_destroy(struct xfs_ifork *);
188 
189 bool		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);
193 bool		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);
197 bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
198 			struct xfs_iext_cursor *cur,
199 			struct xfs_bmbt_irec *gotp);
200 void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
201 			struct xfs_iext_cursor *cur,
202 			struct xfs_bmbt_irec *gotp);
203 
204 void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
205 void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
206 void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
207 void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
208 
209 static 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 
216 static 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  */
226 static 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  */
238 static 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 
252 extern struct kmem_cache	*xfs_ifork_cache;
253 
254 extern void xfs_ifork_init_cow(struct xfs_inode *ip);
255 
256 int xfs_ifork_verify_local_data(struct xfs_inode *ip);
257 int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
258 int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
259 		int nr_to_add);
260 int 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. */
264 static 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