xfs_bmap.h 13 KB

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  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. struct getbmap;
  21. struct xfs_bmbt_irec;
  22. struct xfs_ifork;
  23. struct xfs_inode;
  24. struct xfs_mount;
  25. struct xfs_trans;
  26. /*
  27. * DELTA: describe a change to the in-core extent list.
  28. *
  29. * Internally the use of xed_blockount is somewhat funky.
  30. * xed_blockcount contains an offset much of the time because this
  31. * makes merging changes easier. (xfs_fileoff_t and xfs_filblks_t are
  32. * the same underlying type).
  33. */
  34. typedef struct xfs_extdelta
  35. {
  36. xfs_fileoff_t xed_startoff; /* offset of range */
  37. xfs_filblks_t xed_blockcount; /* blocks in range */
  38. } xfs_extdelta_t;
  39. /*
  40. * List of extents to be free "later".
  41. * The list is kept sorted on xbf_startblock.
  42. */
  43. typedef struct xfs_bmap_free_item
  44. {
  45. xfs_fsblock_t xbfi_startblock;/* starting fs block number */
  46. xfs_extlen_t xbfi_blockcount;/* number of blocks in extent */
  47. struct xfs_bmap_free_item *xbfi_next; /* link to next entry */
  48. } xfs_bmap_free_item_t;
  49. /*
  50. * Header for free extent list.
  51. */
  52. typedef struct xfs_bmap_free
  53. {
  54. xfs_bmap_free_item_t *xbf_first; /* list of to-be-free extents */
  55. int xbf_count; /* count of items on list */
  56. int xbf_low; /* kludge: alloc in low mode */
  57. } xfs_bmap_free_t;
  58. #define XFS_BMAP_MAX_NMAP 4
  59. /*
  60. * Flags for xfs_bmapi
  61. */
  62. #define XFS_BMAPI_WRITE 0x001 /* write operation: allocate space */
  63. #define XFS_BMAPI_DELAY 0x002 /* delayed write operation */
  64. #define XFS_BMAPI_ENTIRE 0x004 /* return entire extent, not trimmed */
  65. #define XFS_BMAPI_METADATA 0x008 /* mapping metadata not user data */
  66. #define XFS_BMAPI_EXACT 0x010 /* allocate only to spec'd bounds */
  67. #define XFS_BMAPI_ATTRFORK 0x020 /* use attribute fork not data */
  68. #define XFS_BMAPI_ASYNC 0x040 /* bunmapi xactions can be async */
  69. #define XFS_BMAPI_RSVBLOCKS 0x080 /* OK to alloc. reserved data blocks */
  70. #define XFS_BMAPI_PREALLOC 0x100 /* preallocation op: unwritten space */
  71. #define XFS_BMAPI_IGSTATE 0x200 /* Ignore state - */
  72. /* combine contig. space */
  73. #define XFS_BMAPI_CONTIG 0x400 /* must allocate only one extent */
  74. /* XFS_BMAPI_DIRECT_IO 0x800 */
  75. #define XFS_BMAPI_CONVERT 0x1000 /* unwritten extent conversion - */
  76. /* need write cache flushing and no */
  77. /* additional allocation alignments */
  78. #define XFS_BMAPI_AFLAG(w) xfs_bmapi_aflag(w)
  79. static inline int xfs_bmapi_aflag(int w)
  80. {
  81. return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
  82. }
  83. /*
  84. * Special values for xfs_bmbt_irec_t br_startblock field.
  85. */
  86. #define DELAYSTARTBLOCK ((xfs_fsblock_t)-1LL)
  87. #define HOLESTARTBLOCK ((xfs_fsblock_t)-2LL)
  88. #define XFS_BMAP_INIT(flp,fbp) xfs_bmap_init(flp,fbp)
  89. static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
  90. {
  91. ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
  92. (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
  93. }
  94. /*
  95. * Argument structure for xfs_bmap_alloc.
  96. */
  97. typedef struct xfs_bmalloca {
  98. xfs_fsblock_t firstblock; /* i/o first block allocated */
  99. xfs_fsblock_t rval; /* starting block of new extent */
  100. xfs_fileoff_t off; /* offset in file filling in */
  101. struct xfs_trans *tp; /* transaction pointer */
  102. struct xfs_inode *ip; /* incore inode pointer */
  103. struct xfs_bmbt_irec *prevp; /* extent before the new one */
  104. struct xfs_bmbt_irec *gotp; /* extent after, or delayed */
  105. xfs_extlen_t alen; /* i/o length asked/allocated */
  106. xfs_extlen_t total; /* total blocks needed for xaction */
  107. xfs_extlen_t minlen; /* mininum allocation size (blocks) */
  108. xfs_extlen_t minleft; /* amount must be left after alloc */
  109. char eof; /* set if allocating past last extent */
  110. char wasdel; /* replacing a delayed allocation */
  111. char userdata;/* set if is user data */
  112. char low; /* low on space, using seq'l ags */
  113. char aeof; /* allocated space at eof */
  114. char conv; /* overwriting unwritten extents */
  115. } xfs_bmalloca_t;
  116. #ifdef __KERNEL__
  117. #if defined(XFS_BMAP_TRACE)
  118. /*
  119. * Trace operations for bmap extent tracing
  120. */
  121. #define XFS_BMAP_KTRACE_DELETE 1
  122. #define XFS_BMAP_KTRACE_INSERT 2
  123. #define XFS_BMAP_KTRACE_PRE_UP 3
  124. #define XFS_BMAP_KTRACE_POST_UP 4
  125. #define XFS_BMAP_TRACE_SIZE 4096 /* size of global trace buffer */
  126. #define XFS_BMAP_KTRACE_SIZE 32 /* size of per-inode trace buffer */
  127. extern ktrace_t *xfs_bmap_trace_buf;
  128. /*
  129. * Add bmap trace insert entries for all the contents of the extent list.
  130. */
  131. void
  132. xfs_bmap_trace_exlist(
  133. char *fname, /* function name */
  134. struct xfs_inode *ip, /* incore inode pointer */
  135. xfs_extnum_t cnt, /* count of entries in list */
  136. int whichfork); /* data or attr fork */
  137. #else
  138. #define xfs_bmap_trace_exlist(f,ip,c,w)
  139. #endif
  140. /*
  141. * Convert inode from non-attributed to attributed.
  142. * Must not be in a transaction, ip must not be locked.
  143. */
  144. int /* error code */
  145. xfs_bmap_add_attrfork(
  146. struct xfs_inode *ip, /* incore inode pointer */
  147. int size, /* space needed for new attribute */
  148. int rsvd); /* flag for reserved block allocation */
  149. /*
  150. * Add the extent to the list of extents to be free at transaction end.
  151. * The list is maintained sorted (by block number).
  152. */
  153. void
  154. xfs_bmap_add_free(
  155. xfs_fsblock_t bno, /* fs block number of extent */
  156. xfs_filblks_t len, /* length of extent */
  157. xfs_bmap_free_t *flist, /* list of extents */
  158. struct xfs_mount *mp); /* mount point structure */
  159. /*
  160. * Routine to clean up the free list data structure when
  161. * an error occurs during a transaction.
  162. */
  163. void
  164. xfs_bmap_cancel(
  165. xfs_bmap_free_t *flist); /* free list to clean up */
  166. /*
  167. * Compute and fill in the value of the maximum depth of a bmap btree
  168. * in this filesystem. Done once, during mount.
  169. */
  170. void
  171. xfs_bmap_compute_maxlevels(
  172. struct xfs_mount *mp, /* file system mount structure */
  173. int whichfork); /* data or attr fork */
  174. /*
  175. * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
  176. * caller. Frees all the extents that need freeing, which must be done
  177. * last due to locking considerations.
  178. *
  179. * Return 1 if the given transaction was committed and a new one allocated,
  180. * and 0 otherwise.
  181. */
  182. int /* error */
  183. xfs_bmap_finish(
  184. struct xfs_trans **tp, /* transaction pointer addr */
  185. xfs_bmap_free_t *flist, /* i/o: list extents to free */
  186. int *committed); /* xact committed or not */
  187. /*
  188. * Returns the file-relative block number of the first unused block in the file.
  189. * This is the lowest-address hole if the file has holes, else the first block
  190. * past the end of file.
  191. */
  192. int /* error */
  193. xfs_bmap_first_unused(
  194. struct xfs_trans *tp, /* transaction pointer */
  195. struct xfs_inode *ip, /* incore inode */
  196. xfs_extlen_t len, /* size of hole to find */
  197. xfs_fileoff_t *unused, /* unused block num */
  198. int whichfork); /* data or attr fork */
  199. /*
  200. * Returns the file-relative block number of the last block + 1 before
  201. * last_block (input value) in the file.
  202. * This is not based on i_size, it is based on the extent list.
  203. * Returns 0 for local files, as they do not have an extent list.
  204. */
  205. int /* error */
  206. xfs_bmap_last_before(
  207. struct xfs_trans *tp, /* transaction pointer */
  208. struct xfs_inode *ip, /* incore inode */
  209. xfs_fileoff_t *last_block, /* last block */
  210. int whichfork); /* data or attr fork */
  211. /*
  212. * Returns the file-relative block number of the first block past eof in
  213. * the file. This is not based on i_size, it is based on the extent list.
  214. * Returns 0 for local files, as they do not have an extent list.
  215. */
  216. int /* error */
  217. xfs_bmap_last_offset(
  218. struct xfs_trans *tp, /* transaction pointer */
  219. struct xfs_inode *ip, /* incore inode */
  220. xfs_fileoff_t *unused, /* last block num */
  221. int whichfork); /* data or attr fork */
  222. /*
  223. * Returns whether the selected fork of the inode has exactly one
  224. * block or not. For the data fork we check this matches di_size,
  225. * implying the file's range is 0..bsize-1.
  226. */
  227. int
  228. xfs_bmap_one_block(
  229. struct xfs_inode *ip, /* incore inode */
  230. int whichfork); /* data or attr fork */
  231. /*
  232. * Read in the extents to iu_extents.
  233. * All inode fields are set up by caller, we just traverse the btree
  234. * and copy the records in.
  235. */
  236. int /* error */
  237. xfs_bmap_read_extents(
  238. struct xfs_trans *tp, /* transaction pointer */
  239. struct xfs_inode *ip, /* incore inode */
  240. int whichfork); /* data or attr fork */
  241. /*
  242. * Map file blocks to filesystem blocks.
  243. * File range is given by the bno/len pair.
  244. * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
  245. * into a hole or past eof.
  246. * Only allocates blocks from a single allocation group,
  247. * to avoid locking problems.
  248. * The returned value in "firstblock" from the first call in a transaction
  249. * must be remembered and presented to subsequent calls in "firstblock".
  250. * An upper bound for the number of blocks to be allocated is supplied to
  251. * the first call in "total"; if no allocation group has that many free
  252. * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
  253. */
  254. int /* error */
  255. xfs_bmapi(
  256. struct xfs_trans *tp, /* transaction pointer */
  257. struct xfs_inode *ip, /* incore inode */
  258. xfs_fileoff_t bno, /* starting file offs. mapped */
  259. xfs_filblks_t len, /* length to map in file */
  260. int flags, /* XFS_BMAPI_... */
  261. xfs_fsblock_t *firstblock, /* first allocated block
  262. controls a.g. for allocs */
  263. xfs_extlen_t total, /* total blocks needed */
  264. struct xfs_bmbt_irec *mval, /* output: map values */
  265. int *nmap, /* i/o: mval size/count */
  266. xfs_bmap_free_t *flist, /* i/o: list extents to free */
  267. xfs_extdelta_t *delta); /* o: change made to incore
  268. extents */
  269. /*
  270. * Map file blocks to filesystem blocks, simple version.
  271. * One block only, read-only.
  272. * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
  273. * For the other flag values, the effect is as if XFS_BMAPI_METADATA
  274. * was set and all the others were clear.
  275. */
  276. int /* error */
  277. xfs_bmapi_single(
  278. struct xfs_trans *tp, /* transaction pointer */
  279. struct xfs_inode *ip, /* incore inode */
  280. int whichfork, /* data or attr fork */
  281. xfs_fsblock_t *fsb, /* output: mapped block */
  282. xfs_fileoff_t bno); /* starting file offs. mapped */
  283. /*
  284. * Unmap (remove) blocks from a file.
  285. * If nexts is nonzero then the number of extents to remove is limited to
  286. * that value. If not all extents in the block range can be removed then
  287. * *done is set.
  288. */
  289. int /* error */
  290. xfs_bunmapi(
  291. struct xfs_trans *tp, /* transaction pointer */
  292. struct xfs_inode *ip, /* incore inode */
  293. xfs_fileoff_t bno, /* starting offset to unmap */
  294. xfs_filblks_t len, /* length to unmap in file */
  295. int flags, /* XFS_BMAPI_... */
  296. xfs_extnum_t nexts, /* number of extents max */
  297. xfs_fsblock_t *firstblock, /* first allocated block
  298. controls a.g. for allocs */
  299. xfs_bmap_free_t *flist, /* i/o: list extents to free */
  300. xfs_extdelta_t *delta, /* o: change made to incore
  301. extents */
  302. int *done); /* set if not done yet */
  303. /*
  304. * Fcntl interface to xfs_bmapi.
  305. */
  306. int /* error code */
  307. xfs_getbmap(
  308. bhv_desc_t *bdp, /* XFS behavior descriptor*/
  309. struct getbmap *bmv, /* user bmap structure */
  310. void __user *ap, /* pointer to user's array */
  311. int iflags); /* interface flags */
  312. /*
  313. * Check if the endoff is outside the last extent. If so the caller will grow
  314. * the allocation to a stripe unit boundary
  315. */
  316. int
  317. xfs_bmap_eof(
  318. struct xfs_inode *ip,
  319. xfs_fileoff_t endoff,
  320. int whichfork,
  321. int *eof);
  322. /*
  323. * Count fsblocks of the given fork.
  324. */
  325. int
  326. xfs_bmap_count_blocks(
  327. xfs_trans_t *tp,
  328. struct xfs_inode *ip,
  329. int whichfork,
  330. int *count);
  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. * Search the extent records for the entry containing block bno.
  342. * If bno lies in a hole, point to the next entry. If bno lies
  343. * past eof, *eofp will be set, and *prevp will contain the last
  344. * entry (null if none). Else, *lastxp will be set to the index
  345. * of the found entry; *gotp will contain the entry.
  346. */
  347. xfs_bmbt_rec_t *
  348. xfs_bmap_search_multi_extents(struct xfs_ifork *, xfs_fileoff_t, int *,
  349. xfs_extnum_t *, xfs_bmbt_irec_t *, xfs_bmbt_irec_t *);
  350. #endif /* __KERNEL__ */
  351. #endif /* __XFS_BMAP_H__ */