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
  13 /*
  14  * Directory/attribute geometry information. There will be one of these for each
  15  * data fork type, and it will be passed around via the xfs_da_args. Global
  16  * structures will be attached to the xfs_mount.
  17  */
  18 struct xfs_da_geometry {
  19         unsigned int    blksize;        /* da block size in bytes */
  20         unsigned int    fsbcount;       /* da block size in filesystem blocks */
  21         uint8_t         fsblog;         /* log2 of _filesystem_ block size */
  22         uint8_t         blklog;         /* log2 of da block size */
  23         unsigned int    node_hdr_size;  /* danode header size in bytes */
  24         unsigned int    node_ents;      /* # of entries in a danode */
  25         unsigned int    magicpct;       /* 37% of block size in bytes */
  26         xfs_dablk_t     datablk;        /* blockno of dir data v2 */
  27         unsigned int    leaf_hdr_size;  /* dir2 leaf header size */
  28         unsigned int    leaf_max_ents;  /* # of entries in dir2 leaf */
  29         xfs_dablk_t     leafblk;        /* blockno of leaf data v2 */
  30         unsigned int    free_hdr_size;  /* dir2 free header size */
  31         unsigned int    free_max_bests; /* # of bests entries in dir2 free */
  32         xfs_dablk_t     freeblk;        /* blockno of free data v2 */
  33         xfs_extnum_t    max_extents;    /* Max. extents in corresponding fork */
  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         const uint8_t   *new_name;      /* new attr name */
  59         void            *value;         /* set of bytes (maybe contain NULLs) */
  60         void            *new_value;     /* new xattr value (may contain NULLs) */
  61         struct xfs_inode *dp;           /* directory inode to manipulate */
  62         struct xfs_trans *trans;        /* current trans (changes over time) */
  63
  64         xfs_ino_t       inumber;        /* input/output inode number */
  65         xfs_ino_t       owner;          /* inode that owns the dir/attr data */
  66
  67         int             valuelen;       /* length of value */
  68         int             new_valuelen;   /* length of new_value */
  69         uint8_t         filetype;       /* filetype of inode for directories */
  70         uint8_t         op_flags;       /* operation flags */
  71         uint8_t         attr_filter;    /* XFS_ATTR_{ROOT,SECURE,INCOMPLETE} */
  72         short           namelen;        /* length of string (maybe no NULL) */
  73         short           new_namelen;    /* length of new attr name */
  74         xfs_dahash_t    hashval;        /* hash value of name */
  75         xfs_extlen_t    total;          /* total blocks needed, for 1st bmap */
  76         int             whichfork;      /* data or attribute fork */
  77         xfs_dablk_t     blkno;          /* blkno of attr leaf of interest */
  78         int             index;          /* index of attr of interest in blk */
  79         xfs_dablk_t     rmtblkno;       /* remote attr value starting blkno */
  80         int             rmtblkcnt;      /* remote attr value block count */
  81         int             rmtvaluelen;    /* remote attr value length in bytes */
  82         xfs_dablk_t     blkno2;         /* blkno of 2nd attr leaf of interest */
  83         int             index2;         /* index of 2nd attr in blk */
  84         xfs_dablk_t     rmtblkno2;      /* remote attr value starting blkno */
  85         int             rmtblkcnt2;     /* remote attr value block count */
  86         int             rmtvaluelen2;   /* remote attr value length in bytes */
  87         enum xfs_dacmp  cmpresult;      /* name compare result for lookups */
  88 } xfs_da_args_t;
  89
  90 /*
  91  * Operation flags:
  92  */
  93 #define XFS_DA_OP_JUSTCHECK     (1u << 0) /* check for ok with no space */
  94 #define XFS_DA_OP_REPLACE       (1u << 1) /* this is an atomic replace op */
  95 #define XFS_DA_OP_ADDNAME       (1u << 2) /* this is an add operation */
  96 #define XFS_DA_OP_OKNOENT       (1u << 3) /* lookup op, ENOENT ok, else die */
  97 #define XFS_DA_OP_CILOOKUP      (1u << 4) /* lookup returns CI name if found */
  98 #define XFS_DA_OP_RECOVERY      (1u << 5) /* Log recovery operation */
  99 #define XFS_DA_OP_LOGGED        (1u << 6) /* Use intent items to track op */
 100
 101 #define XFS_DA_OP_FLAGS \
 102         { XFS_DA_OP_JUSTCHECK,  "JUSTCHECK" }, \
 103         { XFS_DA_OP_REPLACE,    "REPLACE" }, \
 104         { XFS_DA_OP_ADDNAME,    "ADDNAME" }, \
 105         { XFS_DA_OP_OKNOENT,    "OKNOENT" }, \
 106         { XFS_DA_OP_CILOOKUP,   "CILOOKUP" }, \
 107         { XFS_DA_OP_RECOVERY,   "RECOVERY" }, \
 108         { XFS_DA_OP_LOGGED,     "LOGGED" }
 109
 110 /*
 111  * Storage for holding state during Btree searches and split/join ops.
 112  *
 113  * Only need space for 5 intermediate nodes.  With a minimum of 62-way
 114  * fanout to the Btree, we can support over 900 million directory blocks,
 115  * which is slightly more than enough.
 116  */
 117 typedef struct xfs_da_state_blk {
 118         struct xfs_buf  *bp;            /* buffer containing block */
 119         xfs_dablk_t     blkno;          /* filesystem blkno of buffer */
 120         xfs_daddr_t     disk_blkno;     /* on-disk blkno (in BBs) of buffer */
 121         int             index;          /* relevant index into block */
 122         xfs_dahash_t    hashval;        /* last hash value in block */
 123         int             magic;          /* blk's magic number, ie: blk type */
 124 } xfs_da_state_blk_t;
 125
 126 typedef struct xfs_da_state_path {
 127         int                     active;         /* number of active levels */
 128         xfs_da_state_blk_t      blk[XFS_DA_NODE_MAXDEPTH];
 129 } xfs_da_state_path_t;
 130
 131 typedef struct xfs_da_state {
 132         xfs_da_args_t           *args;          /* filename arguments */
 133         struct xfs_mount        *mp;            /* filesystem mount point */
 134         xfs_da_state_path_t     path;           /* search/split paths */
 135         xfs_da_state_path_t     altpath;        /* alternate path for join */
 136         unsigned char           inleaf;         /* insert into 1->lf, 0->splf */
 137         unsigned char           extravalid;     /* T/F: extrablk is in use */
 138         unsigned char           extraafter;     /* T/F: extrablk is after new */
 139         xfs_da_state_blk_t      extrablk;       /* for double-splits on leaves */
 140                                                 /* for dirv2 extrablk is data */
 141 } xfs_da_state_t;
 142
 143 /*
 144  * In-core version of the node header to abstract the differences in the v2 and
 145  * v3 disk format of the headers. Callers need to convert to/from disk format as
 146  * appropriate.
 147  */
 148 struct xfs_da3_icnode_hdr {
 149         uint32_t                forw;
 150         uint32_t                back;
 151         uint16_t                magic;
 152         uint16_t                count;
 153         uint16_t                level;
 154
 155         /*
 156          * Pointer to the on-disk format entries, which are behind the
 157          * variable size (v4 vs v5) header in the on-disk block.
 158          */
 159         struct xfs_da_node_entry *btree;
 160 };
 161
 162 /*
 163  * Utility macros to aid in logging changed structure fields.
 164  */
 165 #define XFS_DA_LOGOFF(BASE, ADDR)       ((char *)(ADDR) - (char *)(BASE))
 166 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)       \
 167                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 168                 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
 169
 170 /*========================================================================
 171  * Function prototypes.
 172  *========================================================================*/
 173
 174 /*
 175  * Routines used for growing the Btree.
 176  */
 177 int     xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
 178                             int level, struct xfs_buf **bpp, int whichfork);
 179 int     xfs_da3_split(xfs_da_state_t *state);
 180
 181 /*
 182  * Routines used for shrinking the Btree.
 183  */
 184 int     xfs_da3_join(xfs_da_state_t *state);
 185 void    xfs_da3_fixhashpath(struct xfs_da_state *state,
 186                             struct xfs_da_state_path *path_to_to_fix);
 187
 188 /*
 189  * Routines used for finding things in the Btree.
 190  */
 191 int     xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
 192 int     xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
 193                                          int forward, int release, int *result);
 194 /*
 195  * Utility routines.
 196  */
 197 int     xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
 198                                        xfs_da_state_blk_t *new_blk);
 199 int     xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
 200                         xfs_dablk_t bno, struct xfs_buf **bpp, int whichfork);
 201 int     xfs_da3_node_read_mapped(struct xfs_trans *tp, struct xfs_inode *dp,
 202                         xfs_daddr_t mappedbno, struct xfs_buf **bpp,
 203                         int whichfork);
 204
 205 /*
 206  * Utility routines.
 207  */
 208
 209 #define XFS_DABUF_MAP_HOLE_OK   (1u << 0)
 210
 211 int     xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 212 int     xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
 213                               int count);
 214 int     xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 215                 xfs_dablk_t bno, struct xfs_buf **bp, int whichfork);
 216 int     xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 217                 xfs_dablk_t bno, unsigned int flags, struct xfs_buf **bpp,
 218                 int whichfork, const struct xfs_buf_ops *ops);
 219 int     xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
 220                 unsigned int flags, int whichfork,
 221                 const struct xfs_buf_ops *ops);
 222 int     xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 223                                           struct xfs_buf *dead_buf);
 224 void    xfs_da_buf_copy(struct xfs_buf *dst, struct xfs_buf *src,
 225                         size_t size);
 226
 227 uint xfs_da_hashname(const uint8_t *name_string, int name_length);
 228 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
 229                                 const unsigned char *name, int len);
 230
 231
 232 struct xfs_da_state *xfs_da_state_alloc(struct xfs_da_args *args);
 233 void xfs_da_state_free(xfs_da_state_t *state);
 234 void xfs_da_state_reset(struct xfs_da_state *state, struct xfs_da_args *args);
 235
 236 void    xfs_da3_node_hdr_from_disk(struct xfs_mount *mp,
 237                 struct xfs_da3_icnode_hdr *to, struct xfs_da_intnode *from);
 238 void    xfs_da3_node_hdr_to_disk(struct xfs_mount *mp,
 239                 struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from);
 240 xfs_failaddr_t xfs_da3_header_check(struct xfs_buf *bp, xfs_ino_t owner);
 241 xfs_failaddr_t xfs_da3_node_header_check(struct xfs_buf *bp, xfs_ino_t owner);
 242
 243 extern struct kmem_cache        *xfs_da_state_cache;
 244
 245 #endif  /* __XFS_DA_BTREE_H__ */