xref: /linux/fs/xfs/libxfs/xfs_bmap.h (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
1 /*
2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #ifndef __XFS_BMAP_H__
19 #define	__XFS_BMAP_H__
20 
21 struct getbmap;
22 struct xfs_bmbt_irec;
23 struct xfs_ifork;
24 struct xfs_inode;
25 struct xfs_mount;
26 struct xfs_trans;
27 
28 extern kmem_zone_t	*xfs_bmap_free_item_zone;
29 
30 /*
31  * Argument structure for xfs_bmap_alloc.
32  */
33 struct xfs_bmalloca {
34 	xfs_fsblock_t		*firstblock; /* i/o first block allocated */
35 	struct xfs_defer_ops	*dfops;	/* bmap freelist */
36 	struct xfs_trans	*tp;	/* transaction pointer */
37 	struct xfs_inode	*ip;	/* incore inode pointer */
38 	struct xfs_bmbt_irec	prev;	/* extent before the new one */
39 	struct xfs_bmbt_irec	got;	/* extent after, or delayed */
40 
41 	xfs_fileoff_t		offset;	/* offset in file filling in */
42 	xfs_extlen_t		length;	/* i/o length asked/allocated */
43 	xfs_fsblock_t		blkno;	/* starting block of new extent */
44 
45 	struct xfs_btree_cur	*cur;	/* btree cursor */
46 	xfs_extnum_t		idx;	/* current extent index */
47 	int			nallocs;/* number of extents alloc'd */
48 	int			logflags;/* flags for transaction logging */
49 
50 	xfs_extlen_t		total;	/* total blocks needed for xaction */
51 	xfs_extlen_t		minlen;	/* minimum allocation size (blocks) */
52 	xfs_extlen_t		minleft; /* amount must be left after alloc */
53 	bool			eof;	/* set if allocating past last extent */
54 	bool			wasdel;	/* replacing a delayed allocation */
55 	bool			aeof;	/* allocated space at eof */
56 	bool			conv;	/* overwriting unwritten extents */
57 	int			datatype;/* data type being allocated */
58 	int			flags;
59 };
60 
61 /*
62  * List of extents to be free "later".
63  * The list is kept sorted on xbf_startblock.
64  */
65 struct xfs_extent_free_item
66 {
67 	xfs_fsblock_t		xefi_startblock;/* starting fs block number */
68 	xfs_extlen_t		xefi_blockcount;/* number of blocks in extent */
69 	struct list_head	xefi_list;
70 	struct xfs_owner_info	xefi_oinfo;	/* extent owner */
71 };
72 
73 #define	XFS_BMAP_MAX_NMAP	4
74 
75 /*
76  * Flags for xfs_bmapi_*
77  */
78 #define XFS_BMAPI_ENTIRE	0x001	/* return entire extent, not trimmed */
79 #define XFS_BMAPI_METADATA	0x002	/* mapping metadata not user data */
80 #define XFS_BMAPI_ATTRFORK	0x004	/* use attribute fork not data */
81 #define XFS_BMAPI_PREALLOC	0x008	/* preallocation op: unwritten space */
82 #define XFS_BMAPI_IGSTATE	0x010	/* Ignore state - */
83 					/* combine contig. space */
84 #define XFS_BMAPI_CONTIG	0x020	/* must allocate only one extent */
85 /*
86  * unwritten extent conversion - this needs write cache flushing and no additional
87  * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
88  * from written to unwritten, otherwise convert from unwritten to written.
89  */
90 #define XFS_BMAPI_CONVERT	0x040
91 
92 /*
93  * allocate zeroed extents - this requires all newly allocated user data extents
94  * to be initialised to zero. It will be ignored if XFS_BMAPI_METADATA is set.
95  * Use in conjunction with XFS_BMAPI_CONVERT to convert unwritten extents found
96  * during the allocation range to zeroed written extents.
97  */
98 #define XFS_BMAPI_ZERO		0x080
99 
100 /*
101  * Map the inode offset to the block given in ap->firstblock.  Primarily
102  * used for reflink.  The range must be in a hole, and this flag cannot be
103  * turned on with PREALLOC or CONVERT, and cannot be used on the attr fork.
104  *
105  * For bunmapi, this flag unmaps the range without adjusting quota, reducing
106  * refcount, or freeing the blocks.
107  */
108 #define XFS_BMAPI_REMAP		0x100
109 
110 /* Map something in the CoW fork. */
111 #define XFS_BMAPI_COWFORK	0x200
112 
113 /* Only convert delalloc space, don't allocate entirely new extents */
114 #define XFS_BMAPI_DELALLOC	0x400
115 
116 #define XFS_BMAPI_FLAGS \
117 	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
118 	{ XFS_BMAPI_METADATA,	"METADATA" }, \
119 	{ XFS_BMAPI_ATTRFORK,	"ATTRFORK" }, \
120 	{ XFS_BMAPI_PREALLOC,	"PREALLOC" }, \
121 	{ XFS_BMAPI_IGSTATE,	"IGSTATE" }, \
122 	{ XFS_BMAPI_CONTIG,	"CONTIG" }, \
123 	{ XFS_BMAPI_CONVERT,	"CONVERT" }, \
124 	{ XFS_BMAPI_ZERO,	"ZERO" }, \
125 	{ XFS_BMAPI_REMAP,	"REMAP" }, \
126 	{ XFS_BMAPI_COWFORK,	"COWFORK" }, \
127 	{ XFS_BMAPI_DELALLOC,	"DELALLOC" }
128 
129 
130 static inline int xfs_bmapi_aflag(int w)
131 {
132 	return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK :
133 	       (w == XFS_COW_FORK ? XFS_BMAPI_COWFORK : 0));
134 }
135 
136 static inline int xfs_bmapi_whichfork(int bmapi_flags)
137 {
138 	if (bmapi_flags & XFS_BMAPI_COWFORK)
139 		return XFS_COW_FORK;
140 	else if (bmapi_flags & XFS_BMAPI_ATTRFORK)
141 		return XFS_ATTR_FORK;
142 	return XFS_DATA_FORK;
143 }
144 
145 /*
146  * Special values for xfs_bmbt_irec_t br_startblock field.
147  */
148 #define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
149 #define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)
150 
151 /*
152  * Flags for xfs_bmap_add_extent*.
153  */
154 #define BMAP_LEFT_CONTIG	(1 << 0)
155 #define BMAP_RIGHT_CONTIG	(1 << 1)
156 #define BMAP_LEFT_FILLING	(1 << 2)
157 #define BMAP_RIGHT_FILLING	(1 << 3)
158 #define BMAP_LEFT_DELAY		(1 << 4)
159 #define BMAP_RIGHT_DELAY	(1 << 5)
160 #define BMAP_LEFT_VALID		(1 << 6)
161 #define BMAP_RIGHT_VALID	(1 << 7)
162 #define BMAP_ATTRFORK		(1 << 8)
163 #define BMAP_COWFORK		(1 << 9)
164 
165 #define XFS_BMAP_EXT_FLAGS \
166 	{ BMAP_LEFT_CONTIG,	"LC" }, \
167 	{ BMAP_RIGHT_CONTIG,	"RC" }, \
168 	{ BMAP_LEFT_FILLING,	"LF" }, \
169 	{ BMAP_RIGHT_FILLING,	"RF" }, \
170 	{ BMAP_ATTRFORK,	"ATTR" }, \
171 	{ BMAP_COWFORK,		"COW" }
172 
173 
174 /*
175  * Return true if the extent is a real, allocated extent, or false if it is  a
176  * delayed allocation, and unwritten extent or a hole.
177  */
178 static inline bool xfs_bmap_is_real_extent(struct xfs_bmbt_irec *irec)
179 {
180 	return irec->br_state != XFS_EXT_UNWRITTEN &&
181 		irec->br_startblock != HOLESTARTBLOCK &&
182 		irec->br_startblock != DELAYSTARTBLOCK &&
183 		!isnullstartblock(irec->br_startblock);
184 }
185 
186 /*
187  * This macro is used to determine how many extents will be shifted
188  * in one write transaction. We could require two splits,
189  * an extent move on the first and an extent merge on the second,
190  * So it is proper that one extent is shifted inside write transaction
191  * at a time.
192  */
193 #define XFS_BMAP_MAX_SHIFT_EXTENTS	1
194 
195 enum shift_direction {
196 	SHIFT_LEFT = 0,
197 	SHIFT_RIGHT,
198 };
199 
200 #ifdef DEBUG
201 void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
202 		int whichfork, unsigned long caller_ip);
203 #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)	\
204 	xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
205 #else
206 #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)
207 #endif
208 
209 void	xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno,
210 		xfs_filblks_t len);
211 void	xfs_trim_extent_eof(struct xfs_bmbt_irec *, struct xfs_inode *);
212 int	xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
213 void	xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
214 void	xfs_bmap_add_free(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
215 			  xfs_fsblock_t bno, xfs_filblks_t len,
216 			  struct xfs_owner_info *oinfo);
217 void	xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
218 int	xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
219 		xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
220 int	xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
221 		xfs_fileoff_t *last_block, int whichfork);
222 int	xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
223 		int whichfork);
224 int	xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
225 int	xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
226 		int whichfork);
227 int	xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
228 		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
229 		int *nmap, int flags);
230 int	xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
231 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
232 		xfs_fsblock_t *firstblock, xfs_extlen_t total,
233 		struct xfs_bmbt_irec *mval, int *nmap,
234 		struct xfs_defer_ops *dfops);
235 int	__xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
236 		xfs_fileoff_t bno, xfs_filblks_t *rlen, int flags,
237 		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
238 		struct xfs_defer_ops *dfops);
239 int	xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
240 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
241 		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
242 		struct xfs_defer_ops *dfops, int *done);
243 int	xfs_bmap_del_extent_delay(struct xfs_inode *ip, int whichfork,
244 		xfs_extnum_t *idx, struct xfs_bmbt_irec *got,
245 		struct xfs_bmbt_irec *del);
246 void	xfs_bmap_del_extent_cow(struct xfs_inode *ip, xfs_extnum_t *idx,
247 		struct xfs_bmbt_irec *got, struct xfs_bmbt_irec *del);
248 uint	xfs_default_attroffset(struct xfs_inode *ip);
249 int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
250 		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
251 		int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
252 		struct xfs_defer_ops *dfops, enum shift_direction direction,
253 		int num_exts);
254 int	xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
255 int	xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,
256 		xfs_fileoff_t off, xfs_filblks_t len, xfs_filblks_t prealloc,
257 		struct xfs_bmbt_irec *got, xfs_extnum_t *lastx, int eof);
258 
259 enum xfs_bmap_intent_type {
260 	XFS_BMAP_MAP = 1,
261 	XFS_BMAP_UNMAP,
262 };
263 
264 struct xfs_bmap_intent {
265 	struct list_head			bi_list;
266 	enum xfs_bmap_intent_type		bi_type;
267 	struct xfs_inode			*bi_owner;
268 	int					bi_whichfork;
269 	struct xfs_bmbt_irec			bi_bmap;
270 };
271 
272 int	xfs_bmap_finish_one(struct xfs_trans *tp, struct xfs_defer_ops *dfops,
273 		struct xfs_inode *ip, enum xfs_bmap_intent_type type,
274 		int whichfork, xfs_fileoff_t startoff, xfs_fsblock_t startblock,
275 		xfs_filblks_t *blockcount, xfs_exntst_t state);
276 int	xfs_bmap_map_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
277 		struct xfs_inode *ip, struct xfs_bmbt_irec *imap);
278 int	xfs_bmap_unmap_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
279 		struct xfs_inode *ip, struct xfs_bmbt_irec *imap);
280 
281 #endif	/* __XFS_BMAP_H__ */
282