fs/xfs/xfs_da_btree.h

   1 /*
   2  * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
   3  * Copyright (c) 2013 Red Hat, Inc.
   4  * All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it would be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write the Free Software Foundation,
  17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #ifndef __XFS_DA_BTREE_H__
  20 #define __XFS_DA_BTREE_H__
  21
  22 struct xfs_bmap_free;
  23 struct xfs_inode;
  24 struct xfs_trans;
  25 struct zone;
  26 struct xfs_dir_ops;
  27
  28 /*========================================================================
  29  * Btree searching and modification structure definitions.
  30  *========================================================================*/
  31
  32 /*
  33  * Search comparison results
  34  */
  35 enum xfs_dacmp {
  36         XFS_CMP_DIFFERENT,      /* names are completely different */
  37         XFS_CMP_EXACT,          /* names are exactly the same */
  38         XFS_CMP_CASE            /* names are same but differ in case */
  39 };
  40
  41 /*
  42  * Structure to ease passing around component names.
  43  */
  44 typedef struct xfs_da_args {
  45         const __uint8_t *name;          /* string (maybe not NULL terminated) */
  46         int             namelen;        /* length of string (maybe no NULL) */
  47         __uint8_t       filetype;       /* filetype of inode for directories */
  48         __uint8_t       *value;         /* set of bytes (maybe contain NULLs) */
  49         int             valuelen;       /* length of value */
  50         int             flags;          /* argument flags (eg: ATTR_NOCREATE) */
  51         xfs_dahash_t    hashval;        /* hash value of name */
  52         xfs_ino_t       inumber;        /* input/output inode number */
  53         struct xfs_inode *dp;           /* directory inode to manipulate */
  54         xfs_fsblock_t   *firstblock;    /* ptr to firstblock for bmap calls */
  55         struct xfs_bmap_free *flist;    /* ptr to freelist for bmap_finish */
  56         struct xfs_trans *trans;        /* current trans (changes over time) */
  57         xfs_extlen_t    total;          /* total blocks needed, for 1st bmap */
  58         int             whichfork;      /* data or attribute fork */
  59         xfs_dablk_t     blkno;          /* blkno of attr leaf of interest */
  60         int             index;          /* index of attr of interest in blk */
  61         xfs_dablk_t     rmtblkno;       /* remote attr value starting blkno */
  62         int             rmtblkcnt;      /* remote attr value block count */
  63         xfs_dablk_t     blkno2;         /* blkno of 2nd attr leaf of interest */
  64         int             index2;         /* index of 2nd attr in blk */
  65         xfs_dablk_t     rmtblkno2;      /* remote attr value starting blkno */
  66         int             rmtblkcnt2;     /* remote attr value block count */
  67         int             op_flags;       /* operation flags */
  68         enum xfs_dacmp  cmpresult;      /* name compare result for lookups */
  69 } xfs_da_args_t;
  70
  71 /*
  72  * Operation flags:
  73  */
  74 #define XFS_DA_OP_JUSTCHECK     0x0001  /* check for ok with no space */
  75 #define XFS_DA_OP_RENAME        0x0002  /* this is an atomic rename op */
  76 #define XFS_DA_OP_ADDNAME       0x0004  /* this is an add operation */
  77 #define XFS_DA_OP_OKNOENT       0x0008  /* lookup/add op, ENOENT ok, else die */
  78 #define XFS_DA_OP_CILOOKUP      0x0010  /* lookup to return CI name if found */
  79
  80 #define XFS_DA_OP_FLAGS \
  81         { XFS_DA_OP_JUSTCHECK,  "JUSTCHECK" }, \
  82         { XFS_DA_OP_RENAME,     "RENAME" }, \
  83         { XFS_DA_OP_ADDNAME,    "ADDNAME" }, \
  84         { XFS_DA_OP_OKNOENT,    "OKNOENT" }, \
  85         { XFS_DA_OP_CILOOKUP,   "CILOOKUP" }
  86
  87 /*
  88  * Storage for holding state during Btree searches and split/join ops.
  89  *
  90  * Only need space for 5 intermediate nodes.  With a minimum of 62-way
  91  * fanout to the Btree, we can support over 900 million directory blocks,
  92  * which is slightly more than enough.
  93  */
  94 typedef struct xfs_da_state_blk {
  95         struct xfs_buf  *bp;            /* buffer containing block */
  96         xfs_dablk_t     blkno;          /* filesystem blkno of buffer */
  97         xfs_daddr_t     disk_blkno;     /* on-disk blkno (in BBs) of buffer */
  98         int             index;          /* relevant index into block */
  99         xfs_dahash_t    hashval;        /* last hash value in block */
 100         int             magic;          /* blk's magic number, ie: blk type */
 101 } xfs_da_state_blk_t;
 102
 103 typedef struct xfs_da_state_path {
 104         int                     active;         /* number of active levels */
 105         xfs_da_state_blk_t      blk[XFS_DA_NODE_MAXDEPTH];
 106 } xfs_da_state_path_t;
 107
 108 typedef struct xfs_da_state {
 109         xfs_da_args_t           *args;          /* filename arguments */
 110         struct xfs_mount        *mp;            /* filesystem mount point */
 111         unsigned int            blocksize;      /* logical block size */
 112         unsigned int            node_ents;      /* how many entries in danode */
 113         xfs_da_state_path_t     path;           /* search/split paths */
 114         xfs_da_state_path_t     altpath;        /* alternate path for join */
 115         unsigned char           inleaf;         /* insert into 1->lf, 0->splf */
 116         unsigned char           extravalid;     /* T/F: extrablk is in use */
 117         unsigned char           extraafter;     /* T/F: extrablk is after new */
 118         xfs_da_state_blk_t      extrablk;       /* for double-splits on leaves */
 119                                                 /* for dirv2 extrablk is data */
 120 } xfs_da_state_t;
 121
 122 /*
 123  * Utility macros to aid in logging changed structure fields.
 124  */
 125 #define XFS_DA_LOGOFF(BASE, ADDR)       ((char *)(ADDR) - (char *)(BASE))
 126 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)       \
 127                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 128                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
 129
 130 /*
 131  * Name ops for directory and/or attr name operations
 132  */
 133 struct xfs_nameops {
 134         xfs_dahash_t    (*hashname)(struct xfs_name *);
 135         enum xfs_dacmp  (*compname)(struct xfs_da_args *,
 136                                         const unsigned char *, int);
 137 };
 138
 139
 140 /*========================================================================
 141  * Function prototypes.
 142  *========================================================================*/
 143
 144 /*
 145  * Routines used for growing the Btree.
 146  */
 147 int     xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
 148                             int level, struct xfs_buf **bpp, int whichfork);
 149 int     xfs_da3_split(xfs_da_state_t *state);
 150
 151 /*
 152  * Routines used for shrinking the Btree.
 153  */
 154 int     xfs_da3_join(xfs_da_state_t *state);
 155 void    xfs_da3_fixhashpath(struct xfs_da_state *state,
 156                             struct xfs_da_state_path *path_to_to_fix);
 157
 158 /*
 159  * Routines used for finding things in the Btree.
 160  */
 161 int     xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
 162 int     xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
 163                                          int forward, int release, int *result);
 164 /*
 165  * Utility routines.
 166  */
 167 int     xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
 168                                        xfs_da_state_blk_t *new_blk);
 169 int     xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
 170                          xfs_dablk_t bno, xfs_daddr_t mappedbno,
 171                          struct xfs_buf **bpp, int which_fork);
 172
 173 /*
 174  * Utility routines.
 175  */
 176 int     xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 177 int     xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
 178                               int count);
 179 int     xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 180                               xfs_dablk_t bno, xfs_daddr_t mappedbno,
 181                               struct xfs_buf **bp, int whichfork);
 182 int     xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 183                                xfs_dablk_t bno, xfs_daddr_t mappedbno,
 184                                struct xfs_buf **bpp, int whichfork,
 185                                const struct xfs_buf_ops *ops);
 186 xfs_daddr_t     xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 187                                 xfs_dablk_t bno, xfs_daddr_t mapped_bno,
 188                                 int whichfork, const struct xfs_buf_ops *ops);
 189 int     xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 190                                           struct xfs_buf *dead_buf);
 191
 192 uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
 193 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
 194                                 const unsigned char *name, int len);
 195
 196
 197 xfs_da_state_t *xfs_da_state_alloc(void);
 198 void xfs_da_state_free(xfs_da_state_t *state);
 199
 200 extern struct kmem_zone *xfs_da_state_zone;
 201 extern const struct xfs_nameops xfs_default_nameops;
 202
 203 #endif  /* __XFS_DA_BTREE_H__ */