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 * DELTA: describe a change to the in-core extent list.
32 *
33 * Internally the use of xed_blockount is somewhat funky.
34 * xed_blockcount contains an offset much of the time because this
35 * makes merging changes easier. (xfs_fileoff_t and xfs_filblks_t are
36 * the same underlying type).
37 */
38 typedef struct xfs_extdelta
39 {
40 xfs_fileoff_t xed_startoff; /* offset of range */
41 xfs_filblks_t xed_blockcount; /* blocks in range */
42 } xfs_extdelta_t;
43
44 /*
45 * List of extents to be free "later".
46 * The list is kept sorted on xbf_startblock.
47 */
48 typedef struct xfs_bmap_free_item
49 {
50 xfs_fsblock_t xbfi_startblock;/* starting fs block number */
51 xfs_extlen_t xbfi_blockcount;/* number of blocks in extent */
52 struct xfs_bmap_free_item *xbfi_next; /* link to next entry */
53 } xfs_bmap_free_item_t;
54
55 /*
56 * Header for free extent list.
57 *
58 * xbf_low is used by the allocator to activate the lowspace algorithm -
59 * when free space is running low the extent allocator may choose to
60 * allocate an extent from an AG without leaving sufficient space for
61 * a btree split when inserting the new extent. In this case the allocator
62 * will enable the lowspace algorithm which is supposed to allow further
63 * allocations (such as btree splits and newroots) to allocate from
64 * sequential AGs. In order to avoid locking AGs out of order the lowspace
65 * algorithm will start searching for free space from AG 0. If the correct
66 * transaction reservations have been made then this algorithm will eventually
67 * find all the space it needs.
68 */
69 typedef struct xfs_bmap_free
70 {
71 xfs_bmap_free_item_t *xbf_first; /* list of to-be-free extents */
72 int xbf_count; /* count of items on list */
73 int xbf_low; /* alloc in low mode */
74 } xfs_bmap_free_t;
75
76 #define XFS_BMAP_MAX_NMAP 4
77
78 /*
79 * Flags for xfs_bmapi
80 */
81 #define XFS_BMAPI_WRITE 0x001 /* write operation: allocate space */
82 #define XFS_BMAPI_DELAY 0x002 /* delayed write operation */
83 #define XFS_BMAPI_ENTIRE 0x004 /* return entire extent, not trimmed */
84 #define XFS_BMAPI_METADATA 0x008 /* mapping metadata not user data */
85 #define XFS_BMAPI_EXACT 0x010 /* allocate only to spec'd bounds */
86 #define XFS_BMAPI_ATTRFORK 0x020 /* use attribute fork not data */
87 #define XFS_BMAPI_ASYNC 0x040 /* bunmapi xactions can be async */
88 #define XFS_BMAPI_RSVBLOCKS 0x080 /* OK to alloc. reserved data blocks */
89 #define XFS_BMAPI_PREALLOC 0x100 /* preallocation op: unwritten space */
90 #define XFS_BMAPI_IGSTATE 0x200 /* Ignore state - */
91 /* combine contig. space */
92 #define XFS_BMAPI_CONTIG 0x400 /* must allocate only one extent */
93 /* XFS_BMAPI_DIRECT_IO 0x800 */
94 #define XFS_BMAPI_CONVERT 0x1000 /* unwritten extent conversion - */
95 /* need write cache flushing and no */
96 /* additional allocation alignments */
97
xfs_bmapi_aflag(int w)98 static inline int xfs_bmapi_aflag(int w)
99 {
100 return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
101 }
102
103 /*
104 * Special values for xfs_bmbt_irec_t br_startblock field.
105 */
106 #define DELAYSTARTBLOCK ((xfs_fsblock_t)-1LL)
107 #define HOLESTARTBLOCK ((xfs_fsblock_t)-2LL)
108
xfs_bmap_init(xfs_bmap_free_t * flp,xfs_fsblock_t * fbp)109 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
110 {
111 ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
112 (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
113 }
114
115 /*
116 * Argument structure for xfs_bmap_alloc.
117 */
118 typedef struct xfs_bmalloca {
119 xfs_fsblock_t firstblock; /* i/o first block allocated */
120 xfs_fsblock_t rval; /* starting block of new extent */
121 xfs_fileoff_t off; /* offset in file filling in */
122 struct xfs_trans *tp; /* transaction pointer */
123 struct xfs_inode *ip; /* incore inode pointer */
124 struct xfs_bmbt_irec *prevp; /* extent before the new one */
125 struct xfs_bmbt_irec *gotp; /* extent after, or delayed */
126 xfs_extlen_t alen; /* i/o length asked/allocated */
127 xfs_extlen_t total; /* total blocks needed for xaction */
128 xfs_extlen_t minlen; /* mininum allocation size (blocks) */
129 xfs_extlen_t minleft; /* amount must be left after alloc */
130 char eof; /* set if allocating past last extent */
131 char wasdel; /* replacing a delayed allocation */
132 char userdata;/* set if is user data */
133 char low; /* low on space, using seq'l ags */
134 char aeof; /* allocated space at eof */
135 char conv; /* overwriting unwritten extents */
136 } xfs_bmalloca_t;
137
138 #if defined(__KERNEL__) && defined(XFS_BMAP_TRACE)
139 /*
140 * Trace operations for bmap extent tracing
141 */
142 #define XFS_BMAP_KTRACE_DELETE 1
143 #define XFS_BMAP_KTRACE_INSERT 2
144 #define XFS_BMAP_KTRACE_PRE_UP 3
145 #define XFS_BMAP_KTRACE_POST_UP 4
146
147 #define XFS_BMAP_TRACE_SIZE 4096 /* size of global trace buffer */
148 #define XFS_BMAP_KTRACE_SIZE 32 /* size of per-inode trace buffer */
149 extern ktrace_t *xfs_bmap_trace_buf;
150
151 /*
152 * Add bmap trace insert entries for all the contents of the extent list.
153 */
154 void
155 xfs_bmap_trace_exlist(
156 const char *fname, /* function name */
157 struct xfs_inode *ip, /* incore inode pointer */
158 xfs_extnum_t cnt, /* count of entries in list */
159 int whichfork); /* data or attr fork */
160 #define XFS_BMAP_TRACE_EXLIST(ip,c,w) \
161 xfs_bmap_trace_exlist(__func__,ip,c,w)
162
163 #else /* __KERNEL__ && XFS_BMAP_TRACE */
164
165 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)
166
167 #endif /* __KERNEL__ && XFS_BMAP_TRACE */
168
169 /*
170 * Convert inode from non-attributed to attributed.
171 * Must not be in a transaction, ip must not be locked.
172 */
173 int /* error code */
174 xfs_bmap_add_attrfork(
175 struct xfs_inode *ip, /* incore inode pointer */
176 int size, /* space needed for new attribute */
177 int rsvd); /* flag for reserved block allocation */
178
179 /*
180 * Add the extent to the list of extents to be free at transaction end.
181 * The list is maintained sorted (by block number).
182 */
183 void
184 xfs_bmap_add_free(
185 xfs_fsblock_t bno, /* fs block number of extent */
186 xfs_filblks_t len, /* length of extent */
187 xfs_bmap_free_t *flist, /* list of extents */
188 struct xfs_mount *mp); /* mount point structure */
189
190 /*
191 * Routine to clean up the free list data structure when
192 * an error occurs during a transaction.
193 */
194 void
195 xfs_bmap_cancel(
196 xfs_bmap_free_t *flist); /* free list to clean up */
197
198 /*
199 * Compute and fill in the value of the maximum depth of a bmap btree
200 * in this filesystem. Done once, during mount.
201 */
202 void
203 xfs_bmap_compute_maxlevels(
204 struct xfs_mount *mp, /* file system mount structure */
205 int whichfork); /* data or attr fork */
206
207 /*
208 * Returns the file-relative block number of the first unused block in the file.
209 * This is the lowest-address hole if the file has holes, else the first block
210 * past the end of file.
211 */
212 int /* error */
213 xfs_bmap_first_unused(
214 struct xfs_trans *tp, /* transaction pointer */
215 struct xfs_inode *ip, /* incore inode */
216 xfs_extlen_t len, /* size of hole to find */
217 xfs_fileoff_t *unused, /* unused block num */
218 int whichfork); /* data or attr fork */
219
220 /*
221 * Returns the file-relative block number of the last block + 1 before
222 * last_block (input value) in the file.
223 * This is not based on i_size, it is based on the extent list.
224 * Returns 0 for local files, as they do not have an extent list.
225 */
226 int /* error */
227 xfs_bmap_last_before(
228 struct xfs_trans *tp, /* transaction pointer */
229 struct xfs_inode *ip, /* incore inode */
230 xfs_fileoff_t *last_block, /* last block */
231 int whichfork); /* data or attr fork */
232
233 /*
234 * Returns the file-relative block number of the first block past eof in
235 * the file. This is not based on i_size, it is based on the extent list.
236 * Returns 0 for local files, as they do not have an extent list.
237 */
238 int /* error */
239 xfs_bmap_last_offset(
240 struct xfs_trans *tp, /* transaction pointer */
241 struct xfs_inode *ip, /* incore inode */
242 xfs_fileoff_t *unused, /* last block num */
243 int whichfork); /* data or attr fork */
244
245 /*
246 * Returns whether the selected fork of the inode has exactly one
247 * block or not. For the data fork we check this matches di_size,
248 * implying the file's range is 0..bsize-1.
249 */
250 int
251 xfs_bmap_one_block(
252 struct xfs_inode *ip, /* incore inode */
253 int whichfork); /* data or attr fork */
254
255 /*
256 * Read in the extents to iu_extents.
257 * All inode fields are set up by caller, we just traverse the btree
258 * and copy the records in.
259 */
260 int /* error */
261 xfs_bmap_read_extents(
262 struct xfs_trans *tp, /* transaction pointer */
263 struct xfs_inode *ip, /* incore inode */
264 int whichfork); /* data or attr fork */
265
266 /*
267 * Map file blocks to filesystem blocks.
268 * File range is given by the bno/len pair.
269 * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
270 * into a hole or past eof.
271 * Only allocates blocks from a single allocation group,
272 * to avoid locking problems.
273 * The returned value in "firstblock" from the first call in a transaction
274 * must be remembered and presented to subsequent calls in "firstblock".
275 * An upper bound for the number of blocks to be allocated is supplied to
276 * the first call in "total"; if no allocation group has that many free
277 * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
278 */
279 int /* error */
280 xfs_bmapi(
281 struct xfs_trans *tp, /* transaction pointer */
282 struct xfs_inode *ip, /* incore inode */
283 xfs_fileoff_t bno, /* starting file offs. mapped */
284 xfs_filblks_t len, /* length to map in file */
285 int flags, /* XFS_BMAPI_... */
286 xfs_fsblock_t *firstblock, /* first allocated block
287 controls a.g. for allocs */
288 xfs_extlen_t total, /* total blocks needed */
289 struct xfs_bmbt_irec *mval, /* output: map values */
290 int *nmap, /* i/o: mval size/count */
291 xfs_bmap_free_t *flist, /* i/o: list extents to free */
292 xfs_extdelta_t *delta); /* o: change made to incore
293 extents */
294
295 /*
296 * Map file blocks to filesystem blocks, simple version.
297 * One block only, read-only.
298 * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
299 * For the other flag values, the effect is as if XFS_BMAPI_METADATA
300 * was set and all the others were clear.
301 */
302 int /* error */
303 xfs_bmapi_single(
304 struct xfs_trans *tp, /* transaction pointer */
305 struct xfs_inode *ip, /* incore inode */
306 int whichfork, /* data or attr fork */
307 xfs_fsblock_t *fsb, /* output: mapped block */
308 xfs_fileoff_t bno); /* starting file offs. mapped */
309
310 /*
311 * Unmap (remove) blocks from a file.
312 * If nexts is nonzero then the number of extents to remove is limited to
313 * that value. If not all extents in the block range can be removed then
314 * *done is set.
315 */
316 int /* error */
317 xfs_bunmapi(
318 struct xfs_trans *tp, /* transaction pointer */
319 struct xfs_inode *ip, /* incore inode */
320 xfs_fileoff_t bno, /* starting offset to unmap */
321 xfs_filblks_t len, /* length to unmap in file */
322 int flags, /* XFS_BMAPI_... */
323 xfs_extnum_t nexts, /* number of extents max */
324 xfs_fsblock_t *firstblock, /* first allocated block
325 controls a.g. for allocs */
326 xfs_bmap_free_t *flist, /* i/o: list extents to free */
327 xfs_extdelta_t *delta, /* o: change made to incore
328 extents */
329 int *done); /* set if not done yet */
330
331 /*
332 * Check an extent list, which has just been read, for
333 * any bit in the extent flag field.
334 */
335 int
336 xfs_check_nostate_extents(
337 struct xfs_ifork *ifp,
338 xfs_extnum_t idx,
339 xfs_extnum_t num);
340
341 #ifdef __KERNEL__
342
343 /*
344 * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
345 * caller. Frees all the extents that need freeing, which must be done
346 * last due to locking considerations.
347 *
348 * Return 1 if the given transaction was committed and a new one allocated,
349 * and 0 otherwise.
350 */
351 int /* error */
352 xfs_bmap_finish(
353 struct xfs_trans **tp, /* transaction pointer addr */
354 xfs_bmap_free_t *flist, /* i/o: list extents to free */
355 int *committed); /* xact committed or not */
356
357 /* bmap to userspace formatter - copy to user & advance pointer */
358 typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);
359
360 /*
361 * Get inode's extents as described in bmv, and format for output.
362 */
363 int /* error code */
364 xfs_getbmap(
365 xfs_inode_t *ip,
366 struct getbmapx *bmv, /* user bmap structure */
367 xfs_bmap_format_t formatter, /* format to user */
368 void *arg); /* formatter arg */
369
370 /*
371 * Check if the endoff is outside the last extent. If so the caller will grow
372 * the allocation to a stripe unit boundary
373 */
374 int
375 xfs_bmap_eof(
376 struct xfs_inode *ip,
377 xfs_fileoff_t endoff,
378 int whichfork,
379 int *eof);
380
381 /*
382 * Count fsblocks of the given fork.
383 */
384 int
385 xfs_bmap_count_blocks(
386 xfs_trans_t *tp,
387 struct xfs_inode *ip,
388 int whichfork,
389 int *count);
390
391 /*
392 * Search the extent records for the entry containing block bno.
393 * If bno lies in a hole, point to the next entry. If bno lies
394 * past eof, *eofp will be set, and *prevp will contain the last
395 * entry (null if none). Else, *lastxp will be set to the index
396 * of the found entry; *gotp will contain the entry.
397 */
398 xfs_bmbt_rec_host_t *
399 xfs_bmap_search_multi_extents(struct xfs_ifork *, xfs_fileoff_t, int *,
400 xfs_extnum_t *, xfs_bmbt_irec_t *, xfs_bmbt_irec_t *);
401
402 #endif /* __KERNEL__ */
403
404 #endif /* __XFS_BMAP_H__ */
405