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Diffstat (limited to 'fs/xfs/xfs_attr_leaf.h')
| -rw-r--r-- | fs/xfs/xfs_attr_leaf.h | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/fs/xfs/xfs_attr_leaf.h b/fs/xfs/xfs_attr_leaf.h new file mode 100644 index 0000000..b1480e0 --- /dev/null +++ b/fs/xfs/xfs_attr_leaf.h @@ -0,0 +1,308 @@ +/* + * Copyright (c) 2000, 2002-2003 Silicon Graphics, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 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. + * + * Further, this software is distributed without any warranty that it is + * free of the rightful claim of any third person regarding infringement + * or the like. Any license provided herein, whether implied or + * otherwise, applies only to this software file. Patent licenses, if + * any, provided herein do not apply to combinations of this program with + * other software, or any other product whatsoever. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, + * Mountain View, CA 94043, or: + * + * http://www.sgi.com + * + * For further information regarding this notice, see: + * + * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ + */ +#ifndef __XFS_ATTR_LEAF_H__ +#define __XFS_ATTR_LEAF_H__ + +/* + * Attribute storage layout, internal structure, access macros, etc. + * + * Attribute lists are structured around Btrees where all the data + * elements are in the leaf nodes. Attribute names are hashed into an int, + * then that int is used as the index into the Btree. Since the hashval + * of an attribute name may not be unique, we may have duplicate keys. The + * internal links in the Btree are logical block offsets into the file. + */ + +struct attrlist; +struct attrlist_cursor_kern; +struct attrnames; +struct xfs_dabuf; +struct xfs_da_args; +struct xfs_da_state; +struct xfs_da_state_blk; +struct xfs_inode; +struct xfs_trans; + +/*======================================================================== + * Attribute structure when equal to XFS_LBSIZE(mp) bytes. + *========================================================================*/ + +/* + * This is the structure of the leaf nodes in the Btree. + * + * Struct leaf_entry's are packed from the top. Name/values grow from the + * bottom but are not packed. The freemap contains run-length-encoded entries + * for the free bytes after the leaf_entry's, but only the N largest such, + * smaller runs are dropped. When the freemap doesn't show enough space + * for an allocation, we compact the name/value area and try again. If we + * still don't have enough space, then we have to split the block. The + * name/value structs (both local and remote versions) must be 32bit aligned. + * + * Since we have duplicate hash keys, for each key that matches, compare + * the actual name string. The root and intermediate node search always + * takes the first-in-the-block key match found, so we should only have + * to work "forw"ard. If none matches, continue with the "forw"ard leaf + * nodes until the hash key changes or the attribute name is found. + * + * We store the fact that an attribute is a ROOT/USER/SECURE attribute in + * the leaf_entry. The namespaces are independent only because we also look + * at the namespace bit when we are looking for a matching attribute name. + * + * We also store a "incomplete" bit in the leaf_entry. It shows that an + * attribute is in the middle of being created and should not be shown to + * the user if we crash during the time that the bit is set. We clear the + * bit when we have finished setting up the attribute. We do this because + * we cannot create some large attributes inside a single transaction, and we + * need some indication that we weren't finished if we crash in the middle. + */ +#define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */ + +typedef struct xfs_attr_leafblock { + struct xfs_attr_leaf_hdr { /* constant-structure header block */ + xfs_da_blkinfo_t info; /* block type, links, etc. */ + __uint16_t count; /* count of active leaf_entry's */ + __uint16_t usedbytes; /* num bytes of names/values stored */ + __uint16_t firstused; /* first used byte in name area */ + __uint8_t holes; /* != 0 if blk needs compaction */ + __uint8_t pad1; + struct xfs_attr_leaf_map { /* RLE map of free bytes */ + __uint16_t base; /* base of free region */ + __uint16_t size; /* length of free region */ + } freemap[XFS_ATTR_LEAF_MAPSIZE]; /* N largest free regions */ + } hdr; + struct xfs_attr_leaf_entry { /* sorted on key, not name */ + xfs_dahash_t hashval; /* hash value of name */ + __uint16_t nameidx; /* index into buffer of name/value */ + __uint8_t flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */ + __uint8_t pad2; /* unused pad byte */ + } entries[1]; /* variable sized array */ + struct xfs_attr_leaf_name_local { + __uint16_t valuelen; /* number of bytes in value */ + __uint8_t namelen; /* length of name bytes */ + __uint8_t nameval[1]; /* name/value bytes */ + } namelist; /* grows from bottom of buf */ + struct xfs_attr_leaf_name_remote { + xfs_dablk_t valueblk; /* block number of value bytes */ + __uint32_t valuelen; /* number of bytes in value */ + __uint8_t namelen; /* length of name bytes */ + __uint8_t name[1]; /* name bytes */ + } valuelist; /* grows from bottom of buf */ +} xfs_attr_leafblock_t; +typedef struct xfs_attr_leaf_hdr xfs_attr_leaf_hdr_t; +typedef struct xfs_attr_leaf_map xfs_attr_leaf_map_t; +typedef struct xfs_attr_leaf_entry xfs_attr_leaf_entry_t; +typedef struct xfs_attr_leaf_name_local xfs_attr_leaf_name_local_t; +typedef struct xfs_attr_leaf_name_remote xfs_attr_leaf_name_remote_t; + +/* + * Flags used in the leaf_entry[i].flags field. + * NOTE: the INCOMPLETE bit must not collide with the flags bits specified + * on the system call, they are "or"ed together for various operations. + */ +#define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */ +#define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */ +#define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */ +#define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */ +#define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT) +#define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT) +#define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT) +#define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT) + +/* + * Alignment for namelist and valuelist entries (since they are mixed + * there can be only one alignment value) + */ +#define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t)) + +/* + * Cast typed pointers for "local" and "remote" name/value structs. + */ +#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_REMOTE) +xfs_attr_leaf_name_remote_t * +xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx); +#define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \ + xfs_attr_leaf_name_remote(leafp,idx) +#else +#define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) /* remote name struct ptr */ \ + ((xfs_attr_leaf_name_remote_t *) \ + &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) +#endif +#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_LOCAL) +xfs_attr_leaf_name_local_t * +xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx); +#define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \ + xfs_attr_leaf_name_local(leafp,idx) +#else +#define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) /* local name struct ptr */ \ + ((xfs_attr_leaf_name_local_t *) \ + &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) +#endif +#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME) +char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx); +#define XFS_ATTR_LEAF_NAME(leafp,idx) xfs_attr_leaf_name(leafp,idx) +#else +#define XFS_ATTR_LEAF_NAME(leafp,idx) /* generic name struct ptr */ \ + (&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) +#endif + +/* + * Calculate total bytes used (including trailing pad for alignment) for + * a "local" name/value structure, a "remote" name/value structure, and + * a pointer which might be either. + */ +#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_REMOTE) +int xfs_attr_leaf_entsize_remote(int nlen); +#define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \ + xfs_attr_leaf_entsize_remote(nlen) +#else +#define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) /* space for remote struct */ \ + (((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ + XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1)) +#endif +#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL) +int xfs_attr_leaf_entsize_local(int nlen, int vlen); +#define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \ + xfs_attr_leaf_entsize_local(nlen,vlen) +#else +#define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) /* space for local struct */ \ + (((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + \ + XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1)) +#endif +#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX) +int xfs_attr_leaf_entsize_local_max(int bsize); +#define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \ + xfs_attr_leaf_entsize_local_max(bsize) +#else +#define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) /* max local struct size */ \ + (((bsize) >> 1) + ((bsize) >> 2)) +#endif + + +/*======================================================================== + * Structure used to pass context around among the routines. + *========================================================================*/ + +typedef struct xfs_attr_list_context { + struct xfs_inode *dp; /* inode */ + struct attrlist_cursor_kern *cursor;/* position in list */ + struct attrlist *alist; /* output buffer */ + int count; /* num used entries */ + int dupcnt; /* count dup hashvals seen */ + int bufsize;/* total buffer size */ + int firstu; /* first used byte in buffer */ + int flags; /* from VOP call */ + int resynch;/* T/F: resynch with cursor */ +} xfs_attr_list_context_t; + +/* + * Used to keep a list of "remote value" extents when unlinking an inode. + */ +typedef struct xfs_attr_inactive_list { + xfs_dablk_t valueblk; /* block number of value bytes */ + int valuelen; /* number of bytes in value */ +} xfs_attr_inactive_list_t; + + +/*======================================================================== + * Function prototypes for the kernel. + *========================================================================*/ + +/* + * Internal routines when dirsize < XFS_LITINO(mp). + */ +int xfs_attr_shortform_create(struct xfs_da_args *args); +int xfs_attr_shortform_add(struct xfs_da_args *add); +int xfs_attr_shortform_lookup(struct xfs_da_args *args); +int xfs_attr_shortform_getvalue(struct xfs_da_args *args); +int xfs_attr_shortform_to_leaf(struct xfs_da_args *args); +int xfs_attr_shortform_remove(struct xfs_da_args *remove); +int xfs_attr_shortform_list(struct xfs_attr_list_context *context); +int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp); + +/* + * Internal routines when dirsize == XFS_LBSIZE(mp). + */ +int xfs_attr_leaf_to_node(struct xfs_da_args *args); +int xfs_attr_leaf_to_shortform(struct xfs_dabuf *bp, + struct xfs_da_args *args); +int xfs_attr_leaf_clearflag(struct xfs_da_args *args); +int xfs_attr_leaf_setflag(struct xfs_da_args *args); +int xfs_attr_leaf_flipflags(xfs_da_args_t *args); + +/* + * Routines used for growing the Btree. + */ +int xfs_attr_leaf_create(struct xfs_da_args *args, xfs_dablk_t which_block, + struct xfs_dabuf **bpp); +int xfs_attr_leaf_split(struct xfs_da_state *state, + struct xfs_da_state_blk *oldblk, + struct xfs_da_state_blk *newblk); +int xfs_attr_leaf_lookup_int(struct xfs_dabuf *leaf, + struct xfs_da_args *args); +int xfs_attr_leaf_getvalue(struct xfs_dabuf *bp, struct xfs_da_args *args); +int xfs_attr_leaf_add(struct xfs_dabuf *leaf_buffer, + struct xfs_da_args *args); +int xfs_attr_leaf_remove(struct xfs_dabuf *leaf_buffer, + struct xfs_da_args *args); +int xfs_attr_leaf_list_int(struct xfs_dabuf *bp, + struct xfs_attr_list_context *context); + +/* + * Routines used for shrinking the Btree. + */ +int xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval); +void xfs_attr_leaf_unbalance(struct xfs_da_state *state, + struct xfs_da_state_blk *drop_blk, + struct xfs_da_state_blk *save_blk); +int xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp); +int xfs_attr_node_inactive(struct xfs_trans **trans, struct xfs_inode *dp, + struct xfs_dabuf *bp, int level); +int xfs_attr_leaf_inactive(struct xfs_trans **trans, struct xfs_inode *dp, + struct xfs_dabuf *bp); +int xfs_attr_leaf_freextent(struct xfs_trans **trans, struct xfs_inode *dp, + xfs_dablk_t blkno, int blkcnt); + +/* + * Utility routines. + */ +xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_dabuf *bp, int *count); +int xfs_attr_leaf_order(struct xfs_dabuf *leaf1_bp, + struct xfs_dabuf *leaf2_bp); +int xfs_attr_leaf_newentsize(struct xfs_da_args *args, int blocksize, + int *local); +int xfs_attr_leaf_entsize(struct xfs_attr_leafblock *leaf, int index); +int xfs_attr_put_listent(struct xfs_attr_list_context *context, + struct attrnames *, char *name, int namelen, + int valuelen); +int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp); + +#endif /* __XFS_ATTR_LEAF_H__ */ |
