2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
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.
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.
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
18 #ifndef __XFS_BMAP_H__
19 #define __XFS_BMAP_H__
28 extern kmem_zone_t *xfs_bmap_free_item_zone;
31 * DELTA: describe a change to the in-core extent list.
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).
38 typedef struct xfs_extdelta
40 xfs_fileoff_t xed_startoff; /* offset of range */
41 xfs_filblks_t xed_blockcount; /* blocks in range */
45 * List of extents to be free "later".
46 * The list is kept sorted on xbf_startblock.
48 typedef struct xfs_bmap_free_item
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;
56 * Header for free extent list.
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.
69 typedef struct xfs_bmap_free
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 */
76 #define XFS_BMAP_MAX_NMAP 4
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 */
98 static inline int xfs_bmapi_aflag(int w)
100 return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
104 * Special values for xfs_bmbt_irec_t br_startblock field.
106 #define DELAYSTARTBLOCK ((xfs_fsblock_t)-1LL)
107 #define HOLESTARTBLOCK ((xfs_fsblock_t)-2LL)
109 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
111 ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
112 (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
116 * Argument structure for xfs_bmap_alloc.
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; /* minimum 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 */
139 * Flags for xfs_bmap_add_extent*.
141 #define BMAP_LEFT_CONTIG (1 << 0)
142 #define BMAP_RIGHT_CONTIG (1 << 1)
143 #define BMAP_LEFT_FILLING (1 << 2)
144 #define BMAP_RIGHT_FILLING (1 << 3)
145 #define BMAP_LEFT_DELAY (1 << 4)
146 #define BMAP_RIGHT_DELAY (1 << 5)
147 #define BMAP_LEFT_VALID (1 << 6)
148 #define BMAP_RIGHT_VALID (1 << 7)
150 #if defined(__KERNEL__) && defined(XFS_BMAP_TRACE)
152 * Trace operations for bmap extent tracing
154 #define XFS_BMAP_KTRACE_DELETE 1
155 #define XFS_BMAP_KTRACE_INSERT 2
156 #define XFS_BMAP_KTRACE_PRE_UP 3
157 #define XFS_BMAP_KTRACE_POST_UP 4
159 #define XFS_BMAP_TRACE_SIZE 4096 /* size of global trace buffer */
160 #define XFS_BMAP_KTRACE_SIZE 32 /* size of per-inode trace buffer */
161 extern ktrace_t *xfs_bmap_trace_buf;
164 * Add bmap trace insert entries for all the contents of the extent list.
167 xfs_bmap_trace_exlist(
168 const char *fname, /* function name */
169 struct xfs_inode *ip, /* incore inode pointer */
170 xfs_extnum_t cnt, /* count of entries in list */
171 int whichfork); /* data or attr fork */
172 #define XFS_BMAP_TRACE_EXLIST(ip,c,w) \
173 xfs_bmap_trace_exlist(__func__,ip,c,w)
175 #else /* __KERNEL__ && XFS_BMAP_TRACE */
177 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)
179 #endif /* __KERNEL__ && XFS_BMAP_TRACE */
182 * Convert inode from non-attributed to attributed.
183 * Must not be in a transaction, ip must not be locked.
186 xfs_bmap_add_attrfork(
187 struct xfs_inode *ip, /* incore inode pointer */
188 int size, /* space needed for new attribute */
189 int rsvd); /* flag for reserved block allocation */
192 * Add the extent to the list of extents to be free at transaction end.
193 * The list is maintained sorted (by block number).
197 xfs_fsblock_t bno, /* fs block number of extent */
198 xfs_filblks_t len, /* length of extent */
199 xfs_bmap_free_t *flist, /* list of extents */
200 struct xfs_mount *mp); /* mount point structure */
203 * Routine to clean up the free list data structure when
204 * an error occurs during a transaction.
208 xfs_bmap_free_t *flist); /* free list to clean up */
211 * Compute and fill in the value of the maximum depth of a bmap btree
212 * in this filesystem. Done once, during mount.
215 xfs_bmap_compute_maxlevels(
216 struct xfs_mount *mp, /* file system mount structure */
217 int whichfork); /* data or attr fork */
220 * Returns the file-relative block number of the first unused block in the file.
221 * This is the lowest-address hole if the file has holes, else the first block
222 * past the end of file.
225 xfs_bmap_first_unused(
226 struct xfs_trans *tp, /* transaction pointer */
227 struct xfs_inode *ip, /* incore inode */
228 xfs_extlen_t len, /* size of hole to find */
229 xfs_fileoff_t *unused, /* unused block num */
230 int whichfork); /* data or attr fork */
233 * Returns the file-relative block number of the last block + 1 before
234 * last_block (input value) in the file.
235 * 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.
239 xfs_bmap_last_before(
240 struct xfs_trans *tp, /* transaction pointer */
241 struct xfs_inode *ip, /* incore inode */
242 xfs_fileoff_t *last_block, /* last block */
243 int whichfork); /* data or attr fork */
246 * Returns the file-relative block number of the first block past eof in
247 * the file. This is not based on i_size, it is based on the extent list.
248 * Returns 0 for local files, as they do not have an extent list.
251 xfs_bmap_last_offset(
252 struct xfs_trans *tp, /* transaction pointer */
253 struct xfs_inode *ip, /* incore inode */
254 xfs_fileoff_t *unused, /* last block num */
255 int whichfork); /* data or attr fork */
258 * Returns whether the selected fork of the inode has exactly one
259 * block or not. For the data fork we check this matches di_size,
260 * implying the file's range is 0..bsize-1.
264 struct xfs_inode *ip, /* incore inode */
265 int whichfork); /* data or attr fork */
268 * Read in the extents to iu_extents.
269 * All inode fields are set up by caller, we just traverse the btree
270 * and copy the records in.
273 xfs_bmap_read_extents(
274 struct xfs_trans *tp, /* transaction pointer */
275 struct xfs_inode *ip, /* incore inode */
276 int whichfork); /* data or attr fork */
279 * Map file blocks to filesystem blocks.
280 * File range is given by the bno/len pair.
281 * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
282 * into a hole or past eof.
283 * Only allocates blocks from a single allocation group,
284 * to avoid locking problems.
285 * The returned value in "firstblock" from the first call in a transaction
286 * must be remembered and presented to subsequent calls in "firstblock".
287 * An upper bound for the number of blocks to be allocated is supplied to
288 * the first call in "total"; if no allocation group has that many free
289 * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
293 struct xfs_trans *tp, /* transaction pointer */
294 struct xfs_inode *ip, /* incore inode */
295 xfs_fileoff_t bno, /* starting file offs. mapped */
296 xfs_filblks_t len, /* length to map in file */
297 int flags, /* XFS_BMAPI_... */
298 xfs_fsblock_t *firstblock, /* first allocated block
299 controls a.g. for allocs */
300 xfs_extlen_t total, /* total blocks needed */
301 struct xfs_bmbt_irec *mval, /* output: map values */
302 int *nmap, /* i/o: mval size/count */
303 xfs_bmap_free_t *flist, /* i/o: list extents to free */
304 xfs_extdelta_t *delta); /* o: change made to incore
308 * Map file blocks to filesystem blocks, simple version.
309 * One block only, read-only.
310 * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
311 * For the other flag values, the effect is as if XFS_BMAPI_METADATA
312 * was set and all the others were clear.
316 struct xfs_trans *tp, /* transaction pointer */
317 struct xfs_inode *ip, /* incore inode */
318 int whichfork, /* data or attr fork */
319 xfs_fsblock_t *fsb, /* output: mapped block */
320 xfs_fileoff_t bno); /* starting file offs. mapped */
323 * Unmap (remove) blocks from a file.
324 * If nexts is nonzero then the number of extents to remove is limited to
325 * that value. If not all extents in the block range can be removed then
330 struct xfs_trans *tp, /* transaction pointer */
331 struct xfs_inode *ip, /* incore inode */
332 xfs_fileoff_t bno, /* starting offset to unmap */
333 xfs_filblks_t len, /* length to unmap in file */
334 int flags, /* XFS_BMAPI_... */
335 xfs_extnum_t nexts, /* number of extents max */
336 xfs_fsblock_t *firstblock, /* first allocated block
337 controls a.g. for allocs */
338 xfs_bmap_free_t *flist, /* i/o: list extents to free */
339 xfs_extdelta_t *delta, /* o: change made to incore
341 int *done); /* set if not done yet */
344 * Check an extent list, which has just been read, for
345 * any bit in the extent flag field.
348 xfs_check_nostate_extents(
349 struct xfs_ifork *ifp,
354 xfs_default_attroffset(
355 struct xfs_inode *ip);
360 * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
361 * caller. Frees all the extents that need freeing, which must be done
362 * last due to locking considerations.
364 * Return 1 if the given transaction was committed and a new one allocated,
369 struct xfs_trans **tp, /* transaction pointer addr */
370 xfs_bmap_free_t *flist, /* i/o: list extents to free */
371 int *committed); /* xact committed or not */
373 /* bmap to userspace formatter - copy to user & advance pointer */
374 typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);
377 * Get inode's extents as described in bmv, and format for output.
382 struct getbmapx *bmv, /* user bmap structure */
383 xfs_bmap_format_t formatter, /* format to user */
384 void *arg); /* formatter arg */
387 * Check if the endoff is outside the last extent. If so the caller will grow
388 * the allocation to a stripe unit boundary
392 struct xfs_inode *ip,
393 xfs_fileoff_t endoff,
398 * Count fsblocks of the given fork.
401 xfs_bmap_count_blocks(
403 struct xfs_inode *ip,
407 #endif /* __KERNEL__ */
409 #endif /* __XFS_BMAP_H__ */