xref: /openbmc/linux/fs/xfs/libxfs/xfs_inode_fork.h (revision e368cd72)
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 	short			if_broot_bytes;	/* bytes allocated for root */
25 	int8_t			if_format;	/* format of this fork */
26 	xfs_extnum_t		if_nextents;	/* # of extents in 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  * Directory entry addition can cause the following,
44  * 1. Data block can be added/removed.
45  *    A new extent can cause extent count to increase by 1.
46  * 2. Free disk block can be added/removed.
47  *    Same behaviour as described above for Data block.
48  * 3. Dabtree blocks.
49  *    XFS_DA_NODE_MAXDEPTH blocks can be added. Each of these can be new
50  *    extents. Hence extent count can increase by XFS_DA_NODE_MAXDEPTH.
51  */
52 #define XFS_IEXT_DIR_MANIP_CNT(mp) \
53 	((XFS_DA_NODE_MAXDEPTH + 1 + 1) * (mp)->m_dir_geo->fsbcount)
54 
55 /*
56  * Adding/removing an xattr can cause XFS_DA_NODE_MAXDEPTH extents to
57  * be added. One extra extent for dabtree in case a local attr is
58  * large enough to cause a double split.  It can also cause extent
59  * count to increase proportional to the size of a remote xattr's
60  * value.
61  */
62 #define XFS_IEXT_ATTR_MANIP_CNT(rmt_blks) \
63 	(XFS_DA_NODE_MAXDEPTH + max(1, rmt_blks))
64 
65 /*
66  * A write to a sub-interval of an existing unwritten extent causes the original
67  * extent to be split into 3 extents
68  * i.e. | Unwritten | Real | Unwritten |
69  * Hence extent count can increase by 2.
70  */
71 #define XFS_IEXT_WRITE_UNWRITTEN_CNT	(2)
72 
73 
74 /*
75  * Moving an extent to data fork can cause a sub-interval of an existing extent
76  * to be unmapped. This will increase extent count by 1. Mapping in the new
77  * extent can increase the extent count by 1 again i.e.
78  * | Old extent | New extent | Old extent |
79  * Hence number of extents increases by 2.
80  */
81 #define XFS_IEXT_REFLINK_END_COW_CNT	(2)
82 
83 /*
84  * Removing an initial range of source/donor file's extent and adding a new
85  * extent (from donor/source file) in its place will cause extent count to
86  * increase by 1.
87  */
88 #define XFS_IEXT_SWAP_RMAP_CNT		(1)
89 
90 /*
91  * Fork handling.
92  */
93 
94 #define XFS_IFORK_Q(ip)			((ip)->i_forkoff != 0)
95 #define XFS_IFORK_BOFF(ip)		((int)((ip)->i_forkoff << 3))
96 
97 #define XFS_IFORK_PTR(ip,w)		\
98 	((w) == XFS_DATA_FORK ? \
99 		&(ip)->i_df : \
100 		((w) == XFS_ATTR_FORK ? \
101 			(ip)->i_afp : \
102 			(ip)->i_cowfp))
103 #define XFS_IFORK_DSIZE(ip) \
104 	(XFS_IFORK_Q(ip) ? XFS_IFORK_BOFF(ip) : XFS_LITINO((ip)->i_mount))
105 #define XFS_IFORK_ASIZE(ip) \
106 	(XFS_IFORK_Q(ip) ? XFS_LITINO((ip)->i_mount) - XFS_IFORK_BOFF(ip) : 0)
107 #define XFS_IFORK_SIZE(ip,w) \
108 	((w) == XFS_DATA_FORK ? \
109 		XFS_IFORK_DSIZE(ip) : \
110 		((w) == XFS_ATTR_FORK ? \
111 			XFS_IFORK_ASIZE(ip) : \
112 			0))
113 #define XFS_IFORK_MAXEXT(ip, w) \
114 	(XFS_IFORK_SIZE(ip, w) / sizeof(xfs_bmbt_rec_t))
115 
116 static inline bool xfs_ifork_has_extents(struct xfs_ifork *ifp)
117 {
118 	return ifp->if_format == XFS_DINODE_FMT_EXTENTS ||
119 		ifp->if_format == XFS_DINODE_FMT_BTREE;
120 }
121 
122 static inline xfs_extnum_t xfs_ifork_nextents(struct xfs_ifork *ifp)
123 {
124 	if (!ifp)
125 		return 0;
126 	return ifp->if_nextents;
127 }
128 
129 static inline int8_t xfs_ifork_format(struct xfs_ifork *ifp)
130 {
131 	if (!ifp)
132 		return XFS_DINODE_FMT_EXTENTS;
133 	return ifp->if_format;
134 }
135 
136 struct xfs_ifork *xfs_ifork_alloc(enum xfs_dinode_fmt format,
137 				xfs_extnum_t nextents);
138 struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
139 
140 int		xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
141 int		xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
142 void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
143 				struct xfs_inode_log_item *, int);
144 void		xfs_idestroy_fork(struct xfs_ifork *ifp);
145 void		xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
146 				int whichfork);
147 void		xfs_iroot_realloc(struct xfs_inode *, int, int);
148 int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
149 int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
150 				  int);
151 void		xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
152 				const void *data, int64_t size);
153 
154 xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
155 void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
156 			struct xfs_bmbt_irec *, int);
157 void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
158 			int);
159 void		xfs_iext_destroy(struct xfs_ifork *);
160 
161 bool		xfs_iext_lookup_extent(struct xfs_inode *ip,
162 			struct xfs_ifork *ifp, xfs_fileoff_t bno,
163 			struct xfs_iext_cursor *cur,
164 			struct xfs_bmbt_irec *gotp);
165 bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,
166 			struct xfs_ifork *ifp, xfs_fileoff_t *end,
167 			struct xfs_iext_cursor *cur,
168 			struct xfs_bmbt_irec *gotp);
169 bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
170 			struct xfs_iext_cursor *cur,
171 			struct xfs_bmbt_irec *gotp);
172 void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
173 			struct xfs_iext_cursor *cur,
174 			struct xfs_bmbt_irec *gotp);
175 
176 void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
177 void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
178 void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
179 void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
180 
181 static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
182 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
183 {
184 	xfs_iext_next(ifp, cur);
185 	return xfs_iext_get_extent(ifp, cur, gotp);
186 }
187 
188 static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
189 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
190 {
191 	xfs_iext_prev(ifp, cur);
192 	return xfs_iext_get_extent(ifp, cur, gotp);
193 }
194 
195 /*
196  * Return the extent after cur in gotp without updating the cursor.
197  */
198 static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
199 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
200 {
201 	struct xfs_iext_cursor ncur = *cur;
202 
203 	xfs_iext_next(ifp, &ncur);
204 	return xfs_iext_get_extent(ifp, &ncur, gotp);
205 }
206 
207 /*
208  * Return the extent before cur in gotp without updating the cursor.
209  */
210 static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
211 		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
212 {
213 	struct xfs_iext_cursor ncur = *cur;
214 
215 	xfs_iext_prev(ifp, &ncur);
216 	return xfs_iext_get_extent(ifp, &ncur, gotp);
217 }
218 
219 #define for_each_xfs_iext(ifp, ext, got)		\
220 	for (xfs_iext_first((ifp), (ext));		\
221 	     xfs_iext_get_extent((ifp), (ext), (got));	\
222 	     xfs_iext_next((ifp), (ext)))
223 
224 extern struct kmem_zone	*xfs_ifork_zone;
225 
226 extern void xfs_ifork_init_cow(struct xfs_inode *ip);
227 
228 int xfs_ifork_verify_local_data(struct xfs_inode *ip);
229 int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
230 int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
231 		int nr_to_add);
232 
233 /* returns true if the fork has extents but they are not read in yet. */
234 static inline bool xfs_need_iread_extents(struct xfs_ifork *ifp)
235 {
236 	return ifp->if_format == XFS_DINODE_FMT_BTREE && ifp->if_height == 0;
237 }
238 
239 #endif	/* __XFS_INODE_FORK_H__ */
240