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 21struct getbmap; 22struct xfs_bmbt_irec; 23struct xfs_ifork; 24struct xfs_inode; 25struct xfs_mount; 26struct xfs_trans; 27 28extern 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 */ 38typedef 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 */ 48typedef 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 */ 69typedef 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 98static 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 109static 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 */ 118typedef 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 */ 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 */ 149extern ktrace_t *xfs_bmap_trace_buf; 150 151/* 152 * Add bmap trace insert entries for all the contents of the extent list. 153 */ 154void 155xfs_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 */ 173int /* error code */ 174xfs_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 */ 183void 184xfs_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 */ 194void 195xfs_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 */ 202void 203xfs_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 */ 212int /* error */ 213xfs_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 */ 226int /* error */ 227xfs_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 */ 238int /* error */ 239xfs_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 */ 250int 251xfs_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 */ 260int /* error */ 261xfs_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 */ 279int /* error */ 280xfs_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 */ 302int /* error */ 303xfs_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 */ 316int /* error */ 317xfs_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 */ 335int 336xfs_check_nostate_extents( 337 struct xfs_ifork *ifp, 338 xfs_extnum_t idx, 339 xfs_extnum_t num); 340 341uint 342xfs_default_attroffset( 343 struct xfs_inode *ip); 344 345#ifdef __KERNEL__ 346 347/* 348 * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi 349 * caller. Frees all the extents that need freeing, which must be done 350 * last due to locking considerations. 351 * 352 * Return 1 if the given transaction was committed and a new one allocated, 353 * and 0 otherwise. 354 */ 355int /* error */ 356xfs_bmap_finish( 357 struct xfs_trans **tp, /* transaction pointer addr */ 358 xfs_bmap_free_t *flist, /* i/o: list extents to free */ 359 int *committed); /* xact committed or not */ 360 361/* bmap to userspace formatter - copy to user & advance pointer */ 362typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *); 363 364/* 365 * Get inode's extents as described in bmv, and format for output. 366 */ 367int /* error code */ 368xfs_getbmap( 369 xfs_inode_t *ip, 370 struct getbmapx *bmv, /* user bmap structure */ 371 xfs_bmap_format_t formatter, /* format to user */ 372 void *arg); /* formatter arg */ 373 374/* 375 * Check if the endoff is outside the last extent. If so the caller will grow 376 * the allocation to a stripe unit boundary 377 */ 378int 379xfs_bmap_eof( 380 struct xfs_inode *ip, 381 xfs_fileoff_t endoff, 382 int whichfork, 383 int *eof); 384 385/* 386 * Count fsblocks of the given fork. 387 */ 388int 389xfs_bmap_count_blocks( 390 xfs_trans_t *tp, 391 struct xfs_inode *ip, 392 int whichfork, 393 int *count); 394 395#endif /* __KERNEL__ */ 396 397#endif /* __XFS_BMAP_H__ */ 398