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Diffstat (limited to 'fs/xfs/xfs_da_btree.h')
| -rw-r--r-- | fs/xfs/xfs_da_btree.h | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/fs/xfs/xfs_da_btree.h b/fs/xfs/xfs_da_btree.h new file mode 100644 index 00000000..6fb3371c --- /dev/null +++ b/fs/xfs/xfs_da_btree.h @@ -0,0 +1,336 @@ +/* + * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc. + * Copyright (c) 2013 Red Hat, Inc. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef __XFS_DA_BTREE_H__ +#define __XFS_DA_BTREE_H__ + +struct xfs_bmap_free; +struct xfs_inode; +struct xfs_trans; +struct zone; + +/*======================================================================== + * Directory Structure when greater than XFS_LBSIZE(mp) bytes. + *========================================================================*/ + +/* + * This structure is common to both leaf nodes and non-leaf nodes in the Btree. + * + * It is used to manage a doubly linked list of all blocks at the same + * level in the Btree, and to identify which type of block this is. + */ +#define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */ +#define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */ +#define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */ +#define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */ + +typedef struct xfs_da_blkinfo { + __be32 forw; /* previous block in list */ + __be32 back; /* following block in list */ + __be16 magic; /* validity check on block */ + __be16 pad; /* unused */ +} xfs_da_blkinfo_t; + +/* + * CRC enabled directory structure types + * + * The headers change size for the additional verification information, but + * otherwise the tree layouts and contents are unchanged. Hence the da btree + * code can use the struct xfs_da_blkinfo for manipulating the tree links and + * magic numbers without modification for both v2 and v3 nodes. + */ +#define XFS_DA3_NODE_MAGIC 0x3ebe /* magic number: non-leaf blocks */ +#define XFS_ATTR3_LEAF_MAGIC 0x3bee /* magic number: attribute leaf blks */ +#define XFS_DIR3_LEAF1_MAGIC 0x3df1 /* magic number: v2 dirlf single blks */ +#define XFS_DIR3_LEAFN_MAGIC 0x3dff /* magic number: v2 dirlf multi blks */ + +struct xfs_da3_blkinfo { + /* + * the node link manipulation code relies on the fact that the first + * element of this structure is the struct xfs_da_blkinfo so it can + * ignore the differences in the rest of the structures. + */ + struct xfs_da_blkinfo hdr; + __be32 crc; /* CRC of block */ + __be64 blkno; /* first block of the buffer */ + __be64 lsn; /* sequence number of last write */ + uuid_t uuid; /* filesystem we belong to */ + __be64 owner; /* inode that owns the block */ +}; + +/* + * This is the structure of the root and intermediate nodes in the Btree. + * The leaf nodes are defined above. + * + * Entries are not packed. + * + * Since we have duplicate keys, use a binary search but always follow + * all match in the block, not just the first match found. + */ +#define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */ + +typedef struct xfs_da_node_hdr { + struct xfs_da_blkinfo info; /* block type, links, etc. */ + __be16 __count; /* count of active entries */ + __be16 __level; /* level above leaves (leaf == 0) */ +} xfs_da_node_hdr_t; + +struct xfs_da3_node_hdr { + struct xfs_da3_blkinfo info; /* block type, links, etc. */ + __be16 __count; /* count of active entries */ + __be16 __level; /* level above leaves (leaf == 0) */ + __be32 __pad32; +}; + +#define XFS_DA3_NODE_CRC_OFF (offsetof(struct xfs_da3_node_hdr, info.crc)) + +typedef struct xfs_da_node_entry { + __be32 hashval; /* hash value for this descendant */ + __be32 before; /* Btree block before this key */ +} xfs_da_node_entry_t; + +typedef struct xfs_da_intnode { + struct xfs_da_node_hdr hdr; + struct xfs_da_node_entry __btree[]; +} xfs_da_intnode_t; + +struct xfs_da3_intnode { + struct xfs_da3_node_hdr hdr; + struct xfs_da_node_entry __btree[]; +}; + +/* + * In-core version of the node header to abstract the differences in the v2 and + * v3 disk format of the headers. Callers need to convert to/from disk format as + * appropriate. + */ +struct xfs_da3_icnode_hdr { + __uint32_t forw; + __uint32_t back; + __uint16_t magic; + __uint16_t count; + __uint16_t level; +}; + +extern void xfs_da3_node_hdr_from_disk(struct xfs_da3_icnode_hdr *to, + struct xfs_da_intnode *from); +extern void xfs_da3_node_hdr_to_disk(struct xfs_da_intnode *to, + struct xfs_da3_icnode_hdr *from); + +static inline int +xfs_da3_node_hdr_size(struct xfs_da_intnode *dap) +{ + if (dap->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) + return sizeof(struct xfs_da3_node_hdr); + return sizeof(struct xfs_da_node_hdr); +} + +static inline struct xfs_da_node_entry * +xfs_da3_node_tree_p(struct xfs_da_intnode *dap) +{ + if (dap->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) { + struct xfs_da3_intnode *dap3 = (struct xfs_da3_intnode *)dap; + return dap3->__btree; + } + return dap->__btree; +} + +extern void xfs_da3_intnode_from_disk(struct xfs_da3_icnode_hdr *to, + struct xfs_da_intnode *from); +extern void xfs_da3_intnode_to_disk(struct xfs_da_intnode *to, + struct xfs_da3_icnode_hdr *from); + +#define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize + +/*======================================================================== + * Btree searching and modification structure definitions. + *========================================================================*/ + +/* + * Search comparison results + */ +enum xfs_dacmp { + XFS_CMP_DIFFERENT, /* names are completely different */ + XFS_CMP_EXACT, /* names are exactly the same */ + XFS_CMP_CASE /* names are same but differ in case */ +}; + +/* + * Structure to ease passing around component names. + */ +typedef struct xfs_da_args { + const __uint8_t *name; /* string (maybe not NULL terminated) */ + int namelen; /* length of string (maybe no NULL) */ + __uint8_t *value; /* set of bytes (maybe contain NULLs) */ + int valuelen; /* length of value */ + int flags; /* argument flags (eg: ATTR_NOCREATE) */ + xfs_dahash_t hashval; /* hash value of name */ + xfs_ino_t inumber; /* input/output inode number */ + struct xfs_inode *dp; /* directory inode to manipulate */ + xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */ + struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */ + struct xfs_trans *trans; /* current trans (changes over time) */ + xfs_extlen_t total; /* total blocks needed, for 1st bmap */ + int whichfork; /* data or attribute fork */ + xfs_dablk_t blkno; /* blkno of attr leaf of interest */ + int index; /* index of attr of interest in blk */ + xfs_dablk_t rmtblkno; /* remote attr value starting blkno */ + int rmtblkcnt; /* remote attr value block count */ + xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */ + int index2; /* index of 2nd attr in blk */ + xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */ + int rmtblkcnt2; /* remote attr value block count */ + int op_flags; /* operation flags */ + enum xfs_dacmp cmpresult; /* name compare result for lookups */ +} xfs_da_args_t; + +/* + * Operation flags: + */ +#define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */ +#define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */ +#define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */ +#define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */ +#define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */ + +#define XFS_DA_OP_FLAGS \ + { XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \ + { XFS_DA_OP_RENAME, "RENAME" }, \ + { XFS_DA_OP_ADDNAME, "ADDNAME" }, \ + { XFS_DA_OP_OKNOENT, "OKNOENT" }, \ + { XFS_DA_OP_CILOOKUP, "CILOOKUP" } + +/* + * Storage for holding state during Btree searches and split/join ops. + * + * Only need space for 5 intermediate nodes. With a minimum of 62-way + * fanout to the Btree, we can support over 900 million directory blocks, + * which is slightly more than enough. + */ +typedef struct xfs_da_state_blk { + struct xfs_buf *bp; /* buffer containing block */ + xfs_dablk_t blkno; /* filesystem blkno of buffer */ + xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */ + int index; /* relevant index into block */ + xfs_dahash_t hashval; /* last hash value in block */ + int magic; /* blk's magic number, ie: blk type */ +} xfs_da_state_blk_t; + +typedef struct xfs_da_state_path { + int active; /* number of active levels */ + xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH]; +} xfs_da_state_path_t; + +typedef struct xfs_da_state { + xfs_da_args_t *args; /* filename arguments */ + struct xfs_mount *mp; /* filesystem mount point */ + unsigned int blocksize; /* logical block size */ + unsigned int node_ents; /* how many entries in danode */ + xfs_da_state_path_t path; /* search/split paths */ + xfs_da_state_path_t altpath; /* alternate path for join */ + unsigned char inleaf; /* insert into 1->lf, 0->splf */ + unsigned char extravalid; /* T/F: extrablk is in use */ + unsigned char extraafter; /* T/F: extrablk is after new */ + xfs_da_state_blk_t extrablk; /* for double-splits on leaves */ + /* for dirv2 extrablk is data */ +} xfs_da_state_t; + +/* + * Utility macros to aid in logging changed structure fields. + */ +#define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE)) +#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \ + (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ + (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) + +/* + * Name ops for directory and/or attr name operations + */ +struct xfs_nameops { + xfs_dahash_t (*hashname)(struct xfs_name *); + enum xfs_dacmp (*compname)(struct xfs_da_args *, + const unsigned char *, int); +}; + + +/*======================================================================== + * Function prototypes. + *========================================================================*/ + +/* + * Routines used for growing the Btree. + */ +int xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno, + int level, struct xfs_buf **bpp, int whichfork); +int xfs_da3_split(xfs_da_state_t *state); + +/* + * Routines used for shrinking the Btree. + */ +int xfs_da3_join(xfs_da_state_t *state); +void xfs_da3_fixhashpath(struct xfs_da_state *state, + struct xfs_da_state_path *path_to_to_fix); + +/* + * Routines used for finding things in the Btree. + */ +int xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result); +int xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, + int forward, int release, int *result); +/* + * Utility routines. + */ +int xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, + xfs_da_state_blk_t *new_blk); +int xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp, + xfs_dablk_t bno, xfs_daddr_t mappedbno, + struct xfs_buf **bpp, int which_fork); + +extern const struct xfs_buf_ops xfs_da3_node_buf_ops; + +/* + * Utility routines. + */ +int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno); +int xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno, + int count); +int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp, + xfs_dablk_t bno, xfs_daddr_t mappedbno, + struct xfs_buf **bp, int whichfork); +int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp, + xfs_dablk_t bno, xfs_daddr_t mappedbno, + struct xfs_buf **bpp, int whichfork, + const struct xfs_buf_ops *ops); +xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp, + xfs_dablk_t bno, xfs_daddr_t mapped_bno, + int whichfork, const struct xfs_buf_ops *ops); +int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, + struct xfs_buf *dead_buf); + +uint xfs_da_hashname(const __uint8_t *name_string, int name_length); +enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args, + const unsigned char *name, int len); + + +xfs_da_state_t *xfs_da_state_alloc(void); +void xfs_da_state_free(xfs_da_state_t *state); + +extern struct kmem_zone *xfs_da_state_zone; +extern const struct xfs_nameops xfs_default_nameops; + +#endif /* __XFS_DA_BTREE_H__ */ |