fs/xfs/libxfs/xfs_da_btree.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
   4  * Copyright (c) 2013 Red Hat, Inc.
   5  * All Rights Reserved.
   6  */
   7 #ifndef __XFS_DA_BTREE_H__
   8 #define __XFS_DA_BTREE_H__
   9
  10 struct xfs_inode;
  11 struct xfs_trans;
  12 struct zone;
  13
  14 /*
  15  * Directory/attribute geometry information. There will be one of these for each
  16  * data fork type, and it will be passed around via the xfs_da_args. Global
  17  * structures will be attached to the xfs_mount.
  18  */
  19 struct xfs_da_geometry {
  20         unsigned int    blksize;        /* da block size in bytes */
  21         unsigned int    fsbcount;       /* da block size in filesystem blocks */
  22         uint8_t         fsblog;         /* log2 of _filesystem_ block size */
  23         uint8_t         blklog;         /* log2 of da block size */
  24         unsigned int    node_hdr_size;  /* danode header size in bytes */
  25         unsigned int    node_ents;      /* # of entries in a danode */
  26         unsigned int    magicpct;       /* 37% of block size in bytes */
  27         xfs_dablk_t     datablk;        /* blockno of dir data v2 */
  28         unsigned int    leaf_hdr_size;  /* dir2 leaf header size */
  29         unsigned int    leaf_max_ents;  /* # of entries in dir2 leaf */
  30         xfs_dablk_t     leafblk;        /* blockno of leaf data v2 */
  31         unsigned int    free_hdr_size;  /* dir2 free header size */
  32         unsigned int    free_max_bests; /* # of bests entries in dir2 free */
  33         xfs_dablk_t     freeblk;        /* blockno of free data v2 */
  34
  35         xfs_dir2_data_aoff_t data_first_offset;
  36         size_t          data_entry_offset;
  37 };
  38
  39 /*========================================================================
  40  * Btree searching and modification structure definitions.
  41  *========================================================================*/
  42
  43 /*
  44  * Search comparison results
  45  */
  46 enum xfs_dacmp {
  47         XFS_CMP_DIFFERENT,      /* names are completely different */
  48         XFS_CMP_EXACT,          /* names are exactly the same */
  49         XFS_CMP_CASE            /* names are same but differ in case */
  50 };
  51
  52 /*
  53  * Structure to ease passing around component names.
  54  */
  55 typedef struct xfs_da_args {
  56         struct xfs_da_geometry *geo;    /* da block geometry */
  57         const uint8_t           *name;          /* string (maybe not NULL terminated) */
  58         int             namelen;        /* length of string (maybe no NULL) */
  59         uint8_t         filetype;       /* filetype of inode for directories */
  60         void            *value;         /* set of bytes (maybe contain NULLs) */
  61         int             valuelen;       /* length of value */
  62         unsigned int    attr_filter;    /* XFS_ATTR_{ROOT,SECURE,INCOMPLETE} */
  63         unsigned int    attr_flags;     /* XATTR_{CREATE,REPLACE} */
  64         xfs_dahash_t    hashval;        /* hash value of name */
  65         xfs_ino_t       inumber;        /* input/output inode number */
  66         struct xfs_inode *dp;           /* directory inode to manipulate */
  67         struct xfs_trans *trans;        /* current trans (changes over time) */
  68         xfs_extlen_t    total;          /* total blocks needed, for 1st bmap */
  69         int             whichfork;      /* data or attribute fork */
  70         xfs_dablk_t     blkno;          /* blkno of attr leaf of interest */
  71         int             index;          /* index of attr of interest in blk */
  72         xfs_dablk_t     rmtblkno;       /* remote attr value starting blkno */
  73         int             rmtblkcnt;      /* remote attr value block count */
  74         int             rmtvaluelen;    /* remote attr value length in bytes */
  75         xfs_dablk_t     blkno2;         /* blkno of 2nd attr leaf of interest */
  76         int             index2;         /* index of 2nd attr in blk */
  77         xfs_dablk_t     rmtblkno2;      /* remote attr value starting blkno */
  78         int             rmtblkcnt2;     /* remote attr value block count */
  79         int             rmtvaluelen2;   /* remote attr value length in bytes */
  80         int             op_flags;       /* operation flags */
  81         enum xfs_dacmp  cmpresult;      /* name compare result for lookups */
  82 } xfs_da_args_t;
  83
  84 /*
  85  * Operation flags:
  86  */
  87 #define XFS_DA_OP_JUSTCHECK     0x0001  /* check for ok with no space */
  88 #define XFS_DA_OP_RENAME        0x0002  /* this is an atomic rename op */
  89 #define XFS_DA_OP_ADDNAME       0x0004  /* this is an add operation */
  90 #define XFS_DA_OP_OKNOENT       0x0008  /* lookup/add op, ENOENT ok, else die */
  91 #define XFS_DA_OP_CILOOKUP      0x0010  /* lookup to return CI name if found */
  92 #define XFS_DA_OP_NOTIME        0x0020  /* don't update inode timestamps */
  93
  94 #define XFS_DA_OP_FLAGS \
  95         { XFS_DA_OP_JUSTCHECK,  "JUSTCHECK" }, \
  96         { XFS_DA_OP_RENAME,     "RENAME" }, \
  97         { XFS_DA_OP_ADDNAME,    "ADDNAME" }, \
  98         { XFS_DA_OP_OKNOENT,    "OKNOENT" }, \
  99         { XFS_DA_OP_CILOOKUP,   "CILOOKUP" }, \
 100         { XFS_DA_OP_NOTIME,     "NOTIME" }
 101
 102 /*
 103  * Storage for holding state during Btree searches and split/join ops.
 104  *
 105  * Only need space for 5 intermediate nodes.  With a minimum of 62-way
 106  * fanout to the Btree, we can support over 900 million directory blocks,
 107  * which is slightly more than enough.
 108  */
 109 typedef struct xfs_da_state_blk {
 110         struct xfs_buf  *bp;            /* buffer containing block */
 111         xfs_dablk_t     blkno;          /* filesystem blkno of buffer */
 112         xfs_daddr_t     disk_blkno;     /* on-disk blkno (in BBs) of buffer */
 113         int             index;          /* relevant index into block */
 114         xfs_dahash_t    hashval;        /* last hash value in block */
 115         int             magic;          /* blk's magic number, ie: blk type */
 116 } xfs_da_state_blk_t;
 117
 118 typedef struct xfs_da_state_path {
 119         int                     active;         /* number of active levels */
 120         xfs_da_state_blk_t      blk[XFS_DA_NODE_MAXDEPTH];
 121 } xfs_da_state_path_t;
 122
 123 typedef struct xfs_da_state {
 124         xfs_da_args_t           *args;          /* filename arguments */
 125         struct xfs_mount        *mp;            /* filesystem mount point */
 126         xfs_da_state_path_t     path;           /* search/split paths */
 127         xfs_da_state_path_t     altpath;        /* alternate path for join */
 128         unsigned char           inleaf;         /* insert into 1->lf, 0->splf */
 129         unsigned char           extravalid;     /* T/F: extrablk is in use */
 130         unsigned char           extraafter;     /* T/F: extrablk is after new */
 131         xfs_da_state_blk_t      extrablk;       /* for double-splits on leaves */
 132                                                 /* for dirv2 extrablk is data */
 133 } xfs_da_state_t;
 134
 135 /*
 136  * In-core version of the node header to abstract the differences in the v2 and
 137  * v3 disk format of the headers. Callers need to convert to/from disk format as
 138  * appropriate.
 139  */
 140 struct xfs_da3_icnode_hdr {
 141         uint32_t                forw;
 142         uint32_t                back;
 143         uint16_t                magic;
 144         uint16_t                count;
 145         uint16_t                level;
 146
 147         /*
 148          * Pointer to the on-disk format entries, which are behind the
 149          * variable size (v4 vs v5) header in the on-disk block.
 150          */
 151         struct xfs_da_node_entry *btree;
 152 };
 153
 154 /*
 155  * Utility macros to aid in logging changed structure fields.
 156  */
 157 #define XFS_DA_LOGOFF(BASE, ADDR)       ((char *)(ADDR) - (char *)(BASE))
 158 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)       \
 159                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 160                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
 161
 162 /*========================================================================
 163  * Function prototypes.
 164  *========================================================================*/
 165
 166 /*
 167  * Routines used for growing the Btree.
 168  */
 169 int     xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
 170                             int level, struct xfs_buf **bpp, int whichfork);
 171 int     xfs_da3_split(xfs_da_state_t *state);
 172
 173 /*
 174  * Routines used for shrinking the Btree.
 175  */
 176 int     xfs_da3_join(xfs_da_state_t *state);
 177 void    xfs_da3_fixhashpath(struct xfs_da_state *state,
 178                             struct xfs_da_state_path *path_to_to_fix);
 179
 180 /*
 181  * Routines used for finding things in the Btree.
 182  */
 183 int     xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
 184 int     xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
 185                                          int forward, int release, int *result);
 186 /*
 187  * Utility routines.
 188  */
 189 int     xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
 190                                        xfs_da_state_blk_t *new_blk);
 191 int     xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
 192                         xfs_dablk_t bno, struct xfs_buf **bpp, int whichfork);
 193 int     xfs_da3_node_read_mapped(struct xfs_trans *tp, struct xfs_inode *dp,
 194                         xfs_daddr_t mappedbno, struct xfs_buf **bpp,
 195                         int whichfork);
 196
 197 /*
 198  * Utility routines.
 199  */
 200
 201 #define XFS_DABUF_MAP_HOLE_OK   (1 << 0)
 202
 203 int     xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 204 int     xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
 205                               int count);
 206 int     xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 207                 xfs_dablk_t bno, struct xfs_buf **bp, int whichfork);
 208 int     xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 209                 xfs_dablk_t bno, unsigned int flags, struct xfs_buf **bpp,
 210                 int whichfork, const struct xfs_buf_ops *ops);
 211 int     xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
 212                 unsigned int flags, int whichfork,
 213                 const struct xfs_buf_ops *ops);
 214 int     xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 215                                           struct xfs_buf *dead_buf);
 216
 217 uint xfs_da_hashname(const uint8_t *name_string, int name_length);
 218 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
 219                                 const unsigned char *name, int len);
 220
 221
 222 struct xfs_da_state *xfs_da_state_alloc(struct xfs_da_args *args);
 223 void xfs_da_state_free(xfs_da_state_t *state);
 224
 225 void    xfs_da3_node_hdr_from_disk(struct xfs_mount *mp,
 226                 struct xfs_da3_icnode_hdr *to, struct xfs_da_intnode *from);
 227 void    xfs_da3_node_hdr_to_disk(struct xfs_mount *mp,
 228                 struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from);
 229
 230 extern struct kmem_zone *xfs_da_state_zone;
 231
 232 #endif  /* __XFS_DA_BTREE_H__ */