fs/xfs/xfs_da_btree.h

   1 /*
   2  * Copyright (c) 2000, 2002 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_DA_BTREE_H__
  33 #define __XFS_DA_BTREE_H__
  34
  35 struct xfs_buf;
  36 struct xfs_bmap_free;
  37 struct xfs_inode;
  38 struct xfs_mount;
  39 struct xfs_trans;
  40 struct zone;
  41
  42 /*========================================================================
  43  * Directory Structure when greater than XFS_LBSIZE(mp) bytes.
  44  *========================================================================*/
  45
  46 /*
  47  * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
  48  *
  49  * Is is used to manage a doubly linked list of all blocks at the same
  50  * level in the Btree, and to identify which type of block this is.
  51  */
  52 #define XFS_DA_NODE_MAGIC       0xfebe  /* magic number: non-leaf blocks */
  53 #define XFS_DIR_LEAF_MAGIC      0xfeeb  /* magic number: directory leaf blks */
  54 #define XFS_ATTR_LEAF_MAGIC     0xfbee  /* magic number: attribute leaf blks */
  55 #define XFS_DIR2_LEAF1_MAGIC    0xd2f1  /* magic number: v2 dirlf single blks */
  56 #define XFS_DIR2_LEAFN_MAGIC    0xd2ff  /* magic number: v2 dirlf multi blks */
  57
  58 #define XFS_DIRX_LEAF_MAGIC(mp) \
  59         (XFS_DIR_IS_V1(mp) ? XFS_DIR_LEAF_MAGIC : XFS_DIR2_LEAFN_MAGIC)
  60
  61 typedef struct xfs_da_blkinfo {
  62         xfs_dablk_t forw;                       /* previous block in list */
  63         xfs_dablk_t back;                       /* following block in list */
  64         __uint16_t magic;                       /* validity check on block */
  65         __uint16_t pad;                         /* unused */
  66 } xfs_da_blkinfo_t;
  67
  68 /*
  69  * This is the structure of the root and intermediate nodes in the Btree.
  70  * The leaf nodes are defined above.
  71  *
  72  * Entries are not packed.
  73  *
  74  * Since we have duplicate keys, use a binary search but always follow
  75  * all match in the block, not just the first match found.
  76  */
  77 #define XFS_DA_NODE_MAXDEPTH    5       /* max depth of Btree */
  78
  79 typedef struct xfs_da_intnode {
  80         struct xfs_da_node_hdr {        /* constant-structure header block */
  81                 xfs_da_blkinfo_t info;  /* block type, links, etc. */
  82                 __uint16_t count;       /* count of active entries */
  83                 __uint16_t level;       /* level above leaves (leaf == 0) */
  84         } hdr;
  85         struct xfs_da_node_entry {
  86                 xfs_dahash_t hashval;   /* hash value for this descendant */
  87                 xfs_dablk_t before;     /* Btree block before this key */
  88         } btree[1];                     /* variable sized array of keys */
  89 } xfs_da_intnode_t;
  90 typedef struct xfs_da_node_hdr xfs_da_node_hdr_t;
  91 typedef struct xfs_da_node_entry xfs_da_node_entry_t;
  92
  93 #define XFS_DA_MAXHASH  ((xfs_dahash_t)-1) /* largest valid hash value */
  94
  95 /*
  96  * Macros used by directory code to interface to the filesystem.
  97  */
  98 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_LBSIZE)
  99 int xfs_lbsize(struct xfs_mount *mp);
 100 #define XFS_LBSIZE(mp)                  xfs_lbsize(mp)
 101 #else
 102 #define XFS_LBSIZE(mp)  ((mp)->m_sb.sb_blocksize)
 103 #endif
 104 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_LBLOG)
 105 int xfs_lblog(struct xfs_mount *mp);
 106 #define XFS_LBLOG(mp)                   xfs_lblog(mp)
 107 #else
 108 #define XFS_LBLOG(mp)   ((mp)->m_sb.sb_blocklog)
 109 #endif
 110
 111 /*
 112  * Macros used by directory code to interface to the kernel
 113  */
 114
 115 /*
 116  * Macros used to manipulate directory off_t's
 117  */
 118 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_MAKE_BNOENTRY)
 119 __uint32_t xfs_da_make_bnoentry(struct xfs_mount *mp, xfs_dablk_t bno,
 120                                 int entry);
 121 #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry)      \
 122         xfs_da_make_bnoentry(mp,bno,entry)
 123 #else
 124 #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry) \
 125         (((bno) << (mp)->m_dircook_elog) | (entry))
 126 #endif
 127 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_MAKE_COOKIE)
 128 xfs_off_t xfs_da_make_cookie(struct xfs_mount *mp, xfs_dablk_t bno, int entry,
 129                                 xfs_dahash_t hash);
 130 #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash)   \
 131         xfs_da_make_cookie(mp,bno,entry,hash)
 132 #else
 133 #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash) \
 134         (((xfs_off_t)XFS_DA_MAKE_BNOENTRY(mp, bno, entry) << 32) | (hash))
 135 #endif
 136 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_HASH)
 137 xfs_dahash_t xfs_da_cookie_hash(struct xfs_mount *mp, xfs_off_t cookie);
 138 #define XFS_DA_COOKIE_HASH(mp,cookie)           xfs_da_cookie_hash(mp,cookie)
 139 #else
 140 #define XFS_DA_COOKIE_HASH(mp,cookie)   ((xfs_dahash_t)(cookie))
 141 #endif
 142 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_BNO)
 143 xfs_dablk_t xfs_da_cookie_bno(struct xfs_mount *mp, xfs_off_t cookie);
 144 #define XFS_DA_COOKIE_BNO(mp,cookie)            xfs_da_cookie_bno(mp,cookie)
 145 #else
 146 #define XFS_DA_COOKIE_BNO(mp,cookie) \
 147         (((xfs_off_t)(cookie) >> 31) == -1LL ? \
 148                 (xfs_dablk_t)0 : \
 149                 (xfs_dablk_t)((xfs_off_t)(cookie) >> ((mp)->m_dircook_elog + 32)))
 150 #endif
 151 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_ENTRY)
 152 int xfs_da_cookie_entry(struct xfs_mount *mp, xfs_off_t cookie);
 153 #define XFS_DA_COOKIE_ENTRY(mp,cookie)          xfs_da_cookie_entry(mp,cookie)
 154 #else
 155 #define XFS_DA_COOKIE_ENTRY(mp,cookie) \
 156         (((xfs_off_t)(cookie) >> 31) == -1LL ? \
 157                 (xfs_dablk_t)0 : \
 158                 (xfs_dablk_t)(((xfs_off_t)(cookie) >> 32) & \
 159                               ((1 << (mp)->m_dircook_elog) - 1)))
 160 #endif
 161
 162
 163 /*========================================================================
 164  * Btree searching and modification structure definitions.
 165  *========================================================================*/
 166
 167 /*
 168  * Structure to ease passing around component names.
 169  */
 170 typedef struct xfs_da_args {
 171         uchar_t         *name;          /* string (maybe not NULL terminated) */
 172         int             namelen;        /* length of string (maybe no NULL) */
 173         uchar_t         *value;         /* set of bytes (maybe contain NULLs) */
 174         int             valuelen;       /* length of value */
 175         int             flags;          /* argument flags (eg: ATTR_NOCREATE) */
 176         xfs_dahash_t    hashval;        /* hash value of name */
 177         xfs_ino_t       inumber;        /* input/output inode number */
 178         struct xfs_inode *dp;           /* directory inode to manipulate */
 179         xfs_fsblock_t   *firstblock;    /* ptr to firstblock for bmap calls */
 180         struct xfs_bmap_free *flist;    /* ptr to freelist for bmap_finish */
 181         struct xfs_trans *trans;        /* current trans (changes over time) */
 182         xfs_extlen_t    total;          /* total blocks needed, for 1st bmap */
 183         int             whichfork;      /* data or attribute fork */
 184         xfs_dablk_t     blkno;          /* blkno of attr leaf of interest */
 185         int             index;          /* index of attr of interest in blk */
 186         xfs_dablk_t     rmtblkno;       /* remote attr value starting blkno */
 187         int             rmtblkcnt;      /* remote attr value block count */
 188         xfs_dablk_t     blkno2;         /* blkno of 2nd attr leaf of interest */
 189         int             index2;         /* index of 2nd attr in blk */
 190         xfs_dablk_t     rmtblkno2;      /* remote attr value starting blkno */
 191         int             rmtblkcnt2;     /* remote attr value block count */
 192         unsigned char   justcheck;      /* T/F: check for ok with no space */
 193         unsigned char   rename;         /* T/F: this is an atomic rename op */
 194         unsigned char   addname;        /* T/F: this is an add operation */
 195         unsigned char   oknoent;        /* T/F: ok to return ENOENT, else die */
 196 } xfs_da_args_t;
 197
 198 /*
 199  * Structure to describe buffer(s) for a block.
 200  * This is needed in the directory version 2 format case, when
 201  * multiple non-contiguous fsblocks might be needed to cover one
 202  * logical directory block.
 203  * If the buffer count is 1 then the data pointer points to the
 204  * same place as the b_addr field for the buffer, else to kmem_alloced memory.
 205  */
 206 typedef struct xfs_dabuf {
 207         int             nbuf;           /* number of buffer pointers present */
 208         short           dirty;          /* data needs to be copied back */
 209         short           bbcount;        /* how large is data in bbs */
 210         void            *data;          /* pointer for buffers' data */
 211 #ifdef XFS_DABUF_DEBUG
 212         inst_t          *ra;            /* return address of caller to make */
 213         struct xfs_dabuf *next;         /* next in global chain */
 214         struct xfs_dabuf *prev;         /* previous in global chain */
 215         struct xfs_buftarg *target;     /* device for buffer */
 216         xfs_daddr_t     blkno;          /* daddr first in bps[0] */
 217 #endif
 218         struct xfs_buf  *bps[1];        /* actually nbuf of these */
 219 } xfs_dabuf_t;
 220 #define XFS_DA_BUF_SIZE(n)      \
 221         (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))
 222
 223 #ifdef XFS_DABUF_DEBUG
 224 extern xfs_dabuf_t      *xfs_dabuf_global_list;
 225 #endif
 226
 227 /*
 228  * Storage for holding state during Btree searches and split/join ops.
 229  *
 230  * Only need space for 5 intermediate nodes.  With a minimum of 62-way
 231  * fanout to the Btree, we can support over 900 million directory blocks,
 232  * which is slightly more than enough.
 233  */
 234 typedef struct xfs_da_state_blk {
 235         xfs_dabuf_t     *bp;            /* buffer containing block */
 236         xfs_dablk_t     blkno;          /* filesystem blkno of buffer */
 237         xfs_daddr_t     disk_blkno;     /* on-disk blkno (in BBs) of buffer */
 238         int             index;          /* relevant index into block */
 239         xfs_dahash_t    hashval;        /* last hash value in block */
 240         int             magic;          /* blk's magic number, ie: blk type */
 241 } xfs_da_state_blk_t;
 242
 243 typedef struct xfs_da_state_path {
 244         int                     active;         /* number of active levels */
 245         xfs_da_state_blk_t      blk[XFS_DA_NODE_MAXDEPTH];
 246 } xfs_da_state_path_t;
 247
 248 typedef struct xfs_da_state {
 249         xfs_da_args_t           *args;          /* filename arguments */
 250         struct xfs_mount        *mp;            /* filesystem mount point */
 251         unsigned int            blocksize;      /* logical block size */
 252         unsigned int            node_ents;      /* how many entries in danode */
 253         xfs_da_state_path_t     path;           /* search/split paths */
 254         xfs_da_state_path_t     altpath;        /* alternate path for join */
 255         unsigned char           inleaf;         /* insert into 1->lf, 0->splf */
 256         unsigned char           extravalid;     /* T/F: extrablk is in use */
 257         unsigned char           extraafter;     /* T/F: extrablk is after new */
 258         xfs_da_state_blk_t      extrablk;       /* for double-splits on leafs */
 259                                                 /* for dirv2 extrablk is data */
 260 } xfs_da_state_t;
 261
 262 /*
 263  * Utility macros to aid in logging changed structure fields.
 264  */
 265 #define XFS_DA_LOGOFF(BASE, ADDR)       ((char *)(ADDR) - (char *)(BASE))
 266 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)       \
 267                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 268                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
 269
 270
 271 #ifdef __KERNEL__
 272 /*========================================================================
 273  * Function prototypes for the kernel.
 274  *========================================================================*/
 275
 276 /*
 277  * Routines used for growing the Btree.
 278  */
 279 int     xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
 280                                          xfs_dabuf_t **bpp, int whichfork);
 281 int     xfs_da_split(xfs_da_state_t *state);
 282
 283 /*
 284  * Routines used for shrinking the Btree.
 285  */
 286 int     xfs_da_join(xfs_da_state_t *state);
 287 void    xfs_da_fixhashpath(xfs_da_state_t *state,
 288                                           xfs_da_state_path_t *path_to_to_fix);
 289
 290 /*
 291  * Routines used for finding things in the Btree.
 292  */
 293 int     xfs_da_node_lookup_int(xfs_da_state_t *state, int *result);
 294 int     xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
 295                                          int forward, int release, int *result);
 296 /*
 297  * Utility routines.
 298  */
 299 int     xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
 300                                        xfs_da_state_blk_t *new_blk);
 301
 302 /*
 303  * Utility routines.
 304  */
 305 int     xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 306 int     xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 307                               xfs_dablk_t bno, xfs_daddr_t mappedbno,
 308                               xfs_dabuf_t **bp, int whichfork);
 309 int     xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 310                                xfs_dablk_t bno, xfs_daddr_t mappedbno,
 311                                xfs_dabuf_t **bpp, int whichfork);
 312 xfs_daddr_t     xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 313                         xfs_dablk_t bno, int whichfork);
 314 int     xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 315                                           xfs_dabuf_t *dead_buf);
 316
 317 uint xfs_da_hashname(uchar_t *name_string, int name_length);
 318 uint xfs_da_log2_roundup(uint i);
 319 xfs_da_state_t *xfs_da_state_alloc(void);
 320 void xfs_da_state_free(xfs_da_state_t *state);
 321
 322 void xfs_da_buf_done(xfs_dabuf_t *dabuf);
 323 void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first,
 324                            uint last);
 325 void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
 326 void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
 327 xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf);
 328
 329 extern struct kmem_zone *xfs_da_state_zone;
 330 #endif  /* __KERNEL__ */
 331
 332 #endif  /* __XFS_DA_BTREE_H__ */