fs/xfs/xfs_bmap.h

   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  * List of extents to be free "later".
  32  * The list is kept sorted on xbf_startblock.
  33  */
  34 typedef struct xfs_bmap_free_item
  35 {
  36         xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
  37         xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
  38         struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
  39 } xfs_bmap_free_item_t;
  40
  41 /*
  42  * Header for free extent list.
  43  *
  44  * xbf_low is used by the allocator to activate the lowspace algorithm -
  45  * when free space is running low the extent allocator may choose to
  46  * allocate an extent from an AG without leaving sufficient space for
  47  * a btree split when inserting the new extent.  In this case the allocator
  48  * will enable the lowspace algorithm which is supposed to allow further
  49  * allocations (such as btree splits and newroots) to allocate from
  50  * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  51  * algorithm will start searching for free space from AG 0.  If the correct
  52  * transaction reservations have been made then this algorithm will eventually
  53  * find all the space it needs.
  54  */
  55 typedef struct xfs_bmap_free
  56 {
  57         xfs_bmap_free_item_t    *xbf_first;     /* list of to-be-free extents */
  58         int                     xbf_count;      /* count of items on list */
  59         int                     xbf_low;        /* alloc in low mode */
  60 } xfs_bmap_free_t;
  61
  62 #define XFS_BMAP_MAX_NMAP       4
  63
  64 /*
  65  * Flags for xfs_bmapi_*
  66  */
  67 #define XFS_BMAPI_ENTIRE        0x001   /* return entire extent, not trimmed */
  68 #define XFS_BMAPI_METADATA      0x002   /* mapping metadata not user data */
  69 #define XFS_BMAPI_ATTRFORK      0x004   /* use attribute fork not data */
  70 #define XFS_BMAPI_PREALLOC      0x008   /* preallocation op: unwritten space */
  71 #define XFS_BMAPI_IGSTATE       0x010   /* Ignore state - */
  72                                         /* combine contig. space */
  73 #define XFS_BMAPI_CONTIG        0x020   /* must allocate only one extent */
  74 /*
  75  * unwritten extent conversion - this needs write cache flushing and no additional
  76  * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
  77  * from written to unwritten, otherwise convert from unwritten to written.
  78  */
  79 #define XFS_BMAPI_CONVERT       0x040
  80
  81 #define XFS_BMAPI_FLAGS \
  82         { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
  83         { XFS_BMAPI_METADATA,   "METADATA" }, \
  84         { XFS_BMAPI_ATTRFORK,   "ATTRFORK" }, \
  85         { XFS_BMAPI_PREALLOC,   "PREALLOC" }, \
  86         { XFS_BMAPI_IGSTATE,    "IGSTATE" }, \
  87         { XFS_BMAPI_CONTIG,     "CONTIG" }, \
  88         { XFS_BMAPI_CONVERT,    "CONVERT" }
  89
  90
  91 static inline int xfs_bmapi_aflag(int w)
  92 {
  93         return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
  94 }
  95
  96 /*
  97  * Special values for xfs_bmbt_irec_t br_startblock field.
  98  */
  99 #define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
 100 #define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
 101
 102 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
 103 {
 104         ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
 105                 (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
 106 }
 107
 108 /*
 109  * Argument structure for xfs_bmap_alloc.
 110  */
 111 typedef struct xfs_bmalloca {
 112         xfs_fsblock_t           *firstblock; /* i/o first block allocated */
 113         struct xfs_bmap_free    *flist; /* bmap freelist */
 114         xfs_fsblock_t           rval;   /* starting block of new extent */
 115         xfs_fileoff_t           off;    /* offset in file filling in */
 116         struct xfs_trans        *tp;    /* transaction pointer */
 117         struct xfs_inode        *ip;    /* incore inode pointer */
 118         struct xfs_bmbt_irec    prev;   /* extent before the new one */
 119         struct xfs_bmbt_irec    got;    /* extent after, or delayed */
 120         xfs_extlen_t            alen;   /* i/o length asked/allocated */
 121         xfs_extlen_t            total;  /* total blocks needed for xaction */
 122         xfs_extlen_t            minlen; /* minimum allocation size (blocks) */
 123         xfs_extlen_t            minleft; /* amount must be left after alloc */
 124         char                    eof;    /* set if allocating past last extent */
 125         char                    wasdel; /* replacing a delayed allocation */
 126         char                    userdata;/* set if is user data */
 127         char                    aeof;   /* allocated space at eof */
 128         char                    conv;   /* overwriting unwritten extents */
 129 } xfs_bmalloca_t;
 130
 131 /*
 132  * Flags for xfs_bmap_add_extent*.
 133  */
 134 #define BMAP_LEFT_CONTIG        (1 << 0)
 135 #define BMAP_RIGHT_CONTIG       (1 << 1)
 136 #define BMAP_LEFT_FILLING       (1 << 2)
 137 #define BMAP_RIGHT_FILLING      (1 << 3)
 138 #define BMAP_LEFT_DELAY         (1 << 4)
 139 #define BMAP_RIGHT_DELAY        (1 << 5)
 140 #define BMAP_LEFT_VALID         (1 << 6)
 141 #define BMAP_RIGHT_VALID        (1 << 7)
 142 #define BMAP_ATTRFORK           (1 << 8)
 143
 144 #define XFS_BMAP_EXT_FLAGS \
 145         { BMAP_LEFT_CONTIG,     "LC" }, \
 146         { BMAP_RIGHT_CONTIG,    "RC" }, \
 147         { BMAP_LEFT_FILLING,    "LF" }, \
 148         { BMAP_RIGHT_FILLING,   "RF" }, \
 149         { BMAP_ATTRFORK,        "ATTR" }
 150
 151 /*
 152  * Add bmap trace insert entries for all the contents of the extent list.
 153  *
 154  * Quite excessive tracing.  Only do this for debug builds.
 155  */
 156 #if defined(__KERNEL) && defined(DEBUG)
 157 void
 158 xfs_bmap_trace_exlist(
 159         struct xfs_inode        *ip,            /* incore inode pointer */
 160         xfs_extnum_t            cnt,            /* count of entries in list */
 161         int                     whichfork,
 162         unsigned long           caller_ip);     /* data or attr fork */
 163 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)   \
 164         xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
 165 #else
 166 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)
 167 #endif
 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 int     xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
 267                 xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 268                 int *nmap, int flags);
 269 int     xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
 270                 xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 271                 int *nmap, int flags);
 272 int     xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
 273                 xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 274                 xfs_fsblock_t *firstblock, xfs_extlen_t total,
 275                 struct xfs_bmbt_irec *mval, int *nmap,
 276                 struct xfs_bmap_free *flist);
 277
 278 /*
 279  * Unmap (remove) blocks from a file.
 280  * If nexts is nonzero then the number of extents to remove is limited to
 281  * that value.  If not all extents in the block range can be removed then
 282  * *done is set.
 283  */
 284 int                                             /* error */
 285 xfs_bunmapi(
 286         struct xfs_trans        *tp,            /* transaction pointer */
 287         struct xfs_inode        *ip,            /* incore inode */
 288         xfs_fileoff_t           bno,            /* starting offset to unmap */
 289         xfs_filblks_t           len,            /* length to unmap in file */
 290         int                     flags,          /* XFS_BMAPI_... */
 291         xfs_extnum_t            nexts,          /* number of extents max */
 292         xfs_fsblock_t           *firstblock,    /* first allocated block
 293                                                    controls a.g. for allocs */
 294         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 295         int                     *done);         /* set if not done yet */
 296
 297 /*
 298  * Check an extent list, which has just been read, for
 299  * any bit in the extent flag field.
 300  */
 301 int
 302 xfs_check_nostate_extents(
 303         struct xfs_ifork        *ifp,
 304         xfs_extnum_t            idx,
 305         xfs_extnum_t            num);
 306
 307 uint
 308 xfs_default_attroffset(
 309         struct xfs_inode        *ip);
 310
 311 #ifdef __KERNEL__
 312
 313 /*
 314  * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
 315  * caller.  Frees all the extents that need freeing, which must be done
 316  * last due to locking considerations.
 317  *
 318  * Return 1 if the given transaction was committed and a new one allocated,
 319  * and 0 otherwise.
 320  */
 321 int                                             /* error */
 322 xfs_bmap_finish(
 323         struct xfs_trans        **tp,           /* transaction pointer addr */
 324         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 325         int                     *committed);    /* xact committed or not */
 326
 327 /* bmap to userspace formatter - copy to user & advance pointer */
 328 typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);
 329
 330 /*
 331  * Get inode's extents as described in bmv, and format for output.
 332  */
 333 int                                             /* error code */
 334 xfs_getbmap(
 335         xfs_inode_t             *ip,
 336         struct getbmapx         *bmv,           /* user bmap structure */
 337         xfs_bmap_format_t       formatter,      /* format to user */
 338         void                    *arg);          /* formatter arg */
 339
 340 /*
 341  * Check if the endoff is outside the last extent. If so the caller will grow
 342  * the allocation to a stripe unit boundary
 343  */
 344 int
 345 xfs_bmap_eof(
 346         struct xfs_inode        *ip,
 347         xfs_fileoff_t           endoff,
 348         int                     whichfork,
 349         int                     *eof);
 350
 351 /*
 352  * Count fsblocks of the given fork.
 353  */
 354 int
 355 xfs_bmap_count_blocks(
 356         xfs_trans_t             *tp,
 357         struct xfs_inode        *ip,
 358         int                     whichfork,
 359         int                     *count);
 360
 361 int
 362 xfs_bmap_punch_delalloc_range(
 363         struct xfs_inode        *ip,
 364         xfs_fileoff_t           start_fsb,
 365         xfs_fileoff_t           length);
 366 #endif  /* __KERNEL__ */
 367
 368 #endif  /* __XFS_BMAP_H__ */