include/xfs_da_btree.h

   1 /*
   2  * Copyright (c) 2000 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_NODE_ENTSIZE_BYNAME      /* space a name uses */ \
  94         (sizeof(xfs_da_node_entry_t))
  95 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_NODE_ENTRIES)
  96 int xfs_da_node_entries(struct xfs_mount *mp);
  97 #define XFS_DA_NODE_ENTRIES(mp)         xfs_da_node_entries(mp)
  98 #else
  99 #define XFS_DA_NODE_ENTRIES(mp)         ((mp)->m_da_node_ents)
 100 #endif
 101
 102 #define XFS_DA_MAXHASH  ((xfs_dahash_t)-1) /* largest valid hash value */
 103
 104 /*
 105  * Macros used by directory code to interface to the filesystem.
 106  */
 107 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_LBSIZE)
 108 int xfs_lbsize(struct xfs_mount *mp);
 109 #define XFS_LBSIZE(mp)                  xfs_lbsize(mp)
 110 #else
 111 #define XFS_LBSIZE(mp)  ((mp)->m_sb.sb_blocksize)
 112 #endif
 113 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_LBLOG)
 114 int xfs_lblog(struct xfs_mount *mp);
 115 #define XFS_LBLOG(mp)                   xfs_lblog(mp)
 116 #else
 117 #define XFS_LBLOG(mp)   ((mp)->m_sb.sb_blocklog)
 118 #endif
 119
 120 /*
 121  * Macros used by directory code to interface to the kernel
 122  */
 123
 124 /*
 125  * Macros used to manipulate directory off_t's
 126  */
 127 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_MAKE_BNOENTRY)
 128 __uint32_t xfs_da_make_bnoentry(struct xfs_mount *mp, xfs_dablk_t bno,
 129                                 int entry);
 130 #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry)      \
 131         xfs_da_make_bnoentry(mp,bno,entry)
 132 #else
 133 #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry) \
 134         (((bno) << (mp)->m_dircook_elog) | (entry))
 135 #endif
 136 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_MAKE_COOKIE)
 137 xfs_off_t xfs_da_make_cookie(struct xfs_mount *mp, xfs_dablk_t bno, int entry,
 138                                 xfs_dahash_t hash);
 139 #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash)   \
 140         xfs_da_make_cookie(mp,bno,entry,hash)
 141 #else
 142 #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash) \
 143         (((xfs_off_t)XFS_DA_MAKE_BNOENTRY(mp, bno, entry) << 32) | (hash))
 144 #endif
 145 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_HASH)
 146 xfs_dahash_t xfs_da_cookie_hash(struct xfs_mount *mp, xfs_off_t cookie);
 147 #define XFS_DA_COOKIE_HASH(mp,cookie)           xfs_da_cookie_hash(mp,cookie)
 148 #else
 149 #define XFS_DA_COOKIE_HASH(mp,cookie)   ((xfs_dahash_t)(cookie))
 150 #endif
 151 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_BNO)
 152 xfs_dablk_t xfs_da_cookie_bno(struct xfs_mount *mp, xfs_off_t cookie);
 153 #define XFS_DA_COOKIE_BNO(mp,cookie)            xfs_da_cookie_bno(mp,cookie)
 154 #else
 155 #define XFS_DA_COOKIE_BNO(mp,cookie) \
 156         (((xfs_off_t)(cookie) >> 31) == -1LL ? \
 157                 (xfs_dablk_t)0 : \
 158                 (xfs_dablk_t)((xfs_off_t)(cookie) >> ((mp)->m_dircook_elog + 32)))
 159 #endif
 160 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_ENTRY)
 161 int xfs_da_cookie_entry(struct xfs_mount *mp, xfs_off_t cookie);
 162 #define XFS_DA_COOKIE_ENTRY(mp,cookie)          xfs_da_cookie_entry(mp,cookie)
 163 #else
 164 #define XFS_DA_COOKIE_ENTRY(mp,cookie) \
 165         (((xfs_off_t)(cookie) >> 31) == -1LL ? \
 166                 (xfs_dablk_t)0 : \
 167                 (xfs_dablk_t)(((xfs_off_t)(cookie) >> 32) & \
 168                               ((1 << (mp)->m_dircook_elog) - 1)))
 169 #endif
 170
 171
 172 /*========================================================================
 173  * Btree searching and modification structure definitions.
 174  *========================================================================*/
 175
 176 /*
 177  * Structure to ease passing around component names.
 178  */
 179 typedef struct xfs_da_args {
 180         uchar_t         *name;          /* string (maybe not NULL terminated) */
 181         int             namelen;        /* length of string (maybe no NULL) */
 182         uchar_t         *value;         /* set of bytes (maybe contain NULLs) */
 183         int             valuelen;       /* length of value */
 184         int             flags;          /* argument flags (eg: ATTR_NOCREATE) */
 185         xfs_dahash_t    hashval;        /* hash value of name */
 186         xfs_ino_t       inumber;        /* input/output inode number */
 187         struct xfs_inode *dp;           /* directory inode to manipulate */
 188         xfs_fsblock_t   *firstblock;    /* ptr to firstblock for bmap calls */
 189         struct xfs_bmap_free *flist;    /* ptr to freelist for bmap_finish */
 190         struct xfs_trans *trans;        /* current trans (changes over time) */
 191         xfs_extlen_t    total;          /* total blocks needed, for 1st bmap */
 192         int             whichfork;      /* data or attribute fork */
 193         xfs_dablk_t     blkno;          /* blkno of attr leaf of interest */
 194         int             index;          /* index of attr of interest in blk */
 195         xfs_dablk_t     rmtblkno;       /* remote attr value starting blkno */
 196         int             rmtblkcnt;      /* remote attr value block count */
 197         int             rename;         /* T/F: this is an atomic rename op */
 198         xfs_dablk_t     blkno2;         /* blkno of 2nd attr leaf of interest */
 199         int             index2;         /* index of 2nd attr in blk */
 200         xfs_dablk_t     rmtblkno2;      /* remote attr value starting blkno */
 201         int             rmtblkcnt2;     /* remote attr value block count */
 202         int             justcheck;      /* check for ok with no space */
 203         int             addname;        /* T/F: this is an add operation */
 204         int             oknoent;        /* T/F: ok to return ENOENT, else die */
 205 } xfs_da_args_t;
 206
 207 /*
 208  * Structure to describe buffer(s) for a block.
 209  * This is needed in the directory version 2 format case, when
 210  * multiple non-contiguous fsblocks might be needed to cover one
 211  * logical directory block.
 212  * If the buffer count is 1 then the data pointer points to the
 213  * same place as the b_addr field for the buffer, else to kmem_alloced memory.
 214  */
 215 typedef struct xfs_dabuf {
 216         int             nbuf;           /* number of buffer pointers present */
 217         short           dirty;          /* data needs to be copied back */
 218         short           bbcount;        /* how large is data in bbs */
 219         void            *data;          /* pointer for buffers' data */
 220 #ifdef XFS_DABUF_DEBUG
 221         inst_t          *ra;            /* return address of caller to make */
 222         struct xfs_dabuf *next;         /* next in global chain */
 223         struct xfs_dabuf *prev;         /* previous in global chain */
 224         kdev_t          dev;            /* device for buffer */
 225         xfs_daddr_t     blkno;          /* daddr first in bps[0] */
 226 #endif
 227         struct xfs_buf  *bps[1];        /* actually nbuf of these */
 228 } xfs_dabuf_t;
 229 #define XFS_DA_BUF_SIZE(n)      \
 230         (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))
 231
 232 #ifdef XFS_DABUF_DEBUG
 233 extern xfs_dabuf_t      *xfs_dabuf_global_list;
 234 #endif
 235
 236 /*
 237  * Storage for holding state during Btree searches and split/join ops.
 238  *
 239  * Only need space for 5 intermediate nodes.  With a minimum of 62-way
 240  * fanout to the Btree, we can support over 900 million directory blocks,
 241  * which is slightly more than enough.
 242  */
 243 typedef struct xfs_da_state_blk {
 244         xfs_dabuf_t     *bp;            /* buffer containing block */
 245         xfs_dablk_t     blkno;          /* filesystem blkno of buffer */
 246         xfs_daddr_t             disk_blkno;     /* on-disk blkno (in BBs) of buffer */
 247         int             index;          /* relevant index into block */
 248         xfs_dahash_t    hashval;        /* last hash value in block */
 249         int             magic;          /* blk's magic number, ie: blk type */
 250 } xfs_da_state_blk_t;
 251
 252 typedef struct xfs_da_state_path {
 253         int                     active;         /* number of active levels */
 254         xfs_da_state_blk_t      blk[XFS_DA_NODE_MAXDEPTH];
 255 } xfs_da_state_path_t;
 256
 257 typedef struct xfs_da_state {
 258         xfs_da_args_t           *args;          /* filename arguments */
 259         struct xfs_mount        *mp;            /* filesystem mount point */
 260         int                     blocksize;      /* logical block size */
 261         int                     inleaf;         /* insert into 1->lf, 0->splf */
 262         xfs_da_state_path_t     path;           /* search/split paths */
 263         xfs_da_state_path_t     altpath;        /* alternate path for join */
 264         int                     extravalid;     /* T/F: extrablk is in use */
 265         int                     extraafter;     /* T/F: extrablk is after new */
 266         xfs_da_state_blk_t      extrablk;       /* for double-splits on leafs */
 267                                                 /* for dirv2 extrablk is data */
 268 } xfs_da_state_t;
 269
 270 /*
 271  * Utility macros to aid in logging changed structure fields.
 272  */
 273 #define XFS_DA_LOGOFF(BASE, ADDR)       ((char *)(ADDR) - (char *)(BASE))
 274 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)       \
 275                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 276                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
 277
 278 /*========================================================================
 279  * Function prototypes for the kernel.
 280  *========================================================================*/
 281
 282 /*
 283  * Routines used for growing the Btree.
 284  */
 285 int     xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
 286                                          xfs_dabuf_t **bpp, int whichfork);
 287 int     xfs_da_split(xfs_da_state_t *state);
 288
 289 /*
 290  * Routines used for shrinking the Btree.
 291  */
 292 int     xfs_da_join(xfs_da_state_t *state);
 293 void    xfs_da_fixhashpath(xfs_da_state_t *state,
 294                                           xfs_da_state_path_t *path_to_to_fix);
 295
 296 /*
 297  * Routines used for finding things in the Btree.
 298  */
 299 int     xfs_da_node_lookup_int(xfs_da_state_t *state, int *result);
 300 int     xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
 301                                          int forward, int release, int *result);
 302 /*
 303  * Utility routines.
 304  */
 305 int     xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
 306                                          xfs_da_state_blk_t *save_blk);
 307 int     xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
 308                                        xfs_da_state_blk_t *new_blk);
 309
 310 /*
 311  * Utility routines.
 312  */
 313 int     xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 314 int     xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 315                               xfs_dablk_t bno, xfs_daddr_t mappedbno,
 316                               xfs_dabuf_t **bp, int whichfork);
 317 int     xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 318                                xfs_dablk_t bno, xfs_daddr_t mappedbno,
 319                                xfs_dabuf_t **bpp, int whichfork);
 320 xfs_daddr_t     xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 321                         xfs_dablk_t bno, int whichfork);
 322 int     xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 323                                           xfs_dabuf_t *dead_buf);
 324
 325 uint xfs_da_hashname(uchar_t *name_string, int name_length);
 326 uint xfs_da_log2_roundup(uint i);
 327 xfs_da_state_t *xfs_da_state_alloc(void);
 328 void xfs_da_state_free(xfs_da_state_t *state);
 329 void xfs_da_state_kill_altpath(xfs_da_state_t *state);
 330
 331 void xfs_da_buf_done(xfs_dabuf_t *dabuf);
 332 void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first,
 333                            uint last);
 334 void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
 335 void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
 336 xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf);
 337
 338 extern struct xfs_zone *xfs_da_state_zone;
 339
 340 #endif  /* __XFS_DA_BTREE_H__ */