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