xfs_inode_fork.h

  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
  9struct xfs_inode_log_item;
 10struct xfs_dinode;
 11
 12/*
 13 * File incore extent information, present for each of data & attr forks.
 14 */
 15struct 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
 82static 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
 88static 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
 95static 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
102static 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
123static inline xfs_extnum_t
124xfs_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
133static inline xfs_extnum_t
134xfs_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
143static inline xfs_extnum_t
144xfs_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
161void xfs_ifork_zap_attr(struct xfs_inode *ip);
162void xfs_ifork_init_attr(struct xfs_inode *ip, enum xfs_dinode_fmt format,
163		xfs_extnum_t nextents);
164struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
165
166int		xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
167int		xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
168void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
169				struct xfs_inode_log_item *, int);
170void		xfs_idestroy_fork(struct xfs_ifork *ifp);
171void *		xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
172				int whichfork);
173struct xfs_btree_block *xfs_broot_alloc(struct xfs_ifork *ifp,
174				size_t new_size);
175struct xfs_btree_block *xfs_broot_realloc(struct xfs_ifork *ifp,
176				size_t new_size);
177
178int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
179int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
180				  int);
181void		xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
182				const void *data, int64_t size);
183
184xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
185void		xfs_iext_insert_raw(struct xfs_ifork *ifp,
186			struct xfs_iext_cursor *cur,
187			struct xfs_bmbt_irec *irec);
188void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
189			struct xfs_bmbt_irec *, int);
190void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
191			int);
192void		xfs_iext_destroy(struct xfs_ifork *);
193
194bool		xfs_iext_lookup_extent(struct xfs_inode *ip,
195			struct xfs_ifork *ifp, xfs_fileoff_t bno,
196			struct xfs_iext_cursor *cur,
197			struct xfs_bmbt_irec *gotp);
198bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,
199			struct xfs_ifork *ifp, xfs_fileoff_t *end,
200			struct xfs_iext_cursor *cur,
201			struct xfs_bmbt_irec *gotp);
202bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
203			struct xfs_iext_cursor *cur,
204			struct xfs_bmbt_irec *gotp);
205void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
206			struct xfs_iext_cursor *cur,
207			struct xfs_bmbt_irec *gotp);
208
209void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
210void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
211void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
212void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
213
214static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
215		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
216{
217	xfs_iext_next(ifp, cur);
218	return xfs_iext_get_extent(ifp, cur, gotp);
219}
220
221static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
222		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
223{
224	xfs_iext_prev(ifp, cur);
225	return xfs_iext_get_extent(ifp, cur, gotp);
226}
227
228/*
229 * Return the extent after cur in gotp without updating the cursor.
230 */
231static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
232		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
233{
234	struct xfs_iext_cursor ncur = *cur;
235
236	xfs_iext_next(ifp, &ncur);
237	return xfs_iext_get_extent(ifp, &ncur, gotp);
238}
239
240/*
241 * Return the extent before cur in gotp without updating the cursor.
242 */
243static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
244		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
245{
246	struct xfs_iext_cursor ncur = *cur;
247
248	xfs_iext_prev(ifp, &ncur);
249	return xfs_iext_get_extent(ifp, &ncur, gotp);
250}
251
252#define for_each_xfs_iext(ifp, ext, got)		\
253	for (xfs_iext_first((ifp), (ext));		\
254	     xfs_iext_get_extent((ifp), (ext), (got));	\
255	     xfs_iext_next((ifp), (ext)))
256
257extern struct kmem_cache	*xfs_ifork_cache;
258
259extern void xfs_ifork_init_cow(struct xfs_inode *ip);
260
261int xfs_ifork_verify_local_data(struct xfs_inode *ip);
262int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
263int xfs_iext_count_extend(struct xfs_trans *tp, struct xfs_inode *ip,
264		int whichfork, uint nr_to_add);
265bool xfs_ifork_is_realtime(struct xfs_inode *ip, int whichfork);
266
267/* returns true if the fork has extents but they are not read in yet. */
268static inline bool xfs_need_iread_extents(const struct xfs_ifork *ifp)
269{
270	/* see xfs_iformat_{data,attr}_fork() for needextents semantics */
271	return smp_load_acquire(&ifp->if_needextents) != 0;
272}
273
274#endif	/* __XFS_INODE_FORK_H__ */