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/* * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, 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_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 an "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_leaf_map { /* RLE map of free bytes */ __uint16_t base; /* base of free region */ __uint16_t size; /* length of free region */ } xfs_attr_leaf_map_t; typedef 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; xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE]; /* N largest free regions */ } xfs_attr_leaf_hdr_t; typedef 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 */ } xfs_attr_leaf_entry_t; typedef 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 */ } xfs_attr_leaf_name_local_t; typedef 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 */ } xfs_attr_leaf_name_remote_t; typedef struct xfs_attr_leafblock { xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */ xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */ xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */ xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */ } xfs_attr_leafblock_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. */ #define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \ xfs_attr_leaf_name_remote(leafp,idx) static inline xfs_attr_leaf_name_remote_t * xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx) { return (xfs_attr_leaf_name_remote_t *) &((char *) (leafp))[INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT)]; } #define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \ xfs_attr_leaf_name_local(leafp,idx) static inline xfs_attr_leaf_name_local_t * xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx) { return (xfs_attr_leaf_name_local_t *) &((char *) (leafp))[INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT)]; } #define XFS_ATTR_LEAF_NAME(leafp,idx) \ xfs_attr_leaf_name(leafp,idx) static inline char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx) { return (&((char *) (leafp))[INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT)]); } /* * 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. */ #define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \ xfs_attr_leaf_entsize_remote(nlen) static inline int xfs_attr_leaf_entsize_remote(int nlen) { return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); } #define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \ xfs_attr_leaf_entsize_local(nlen,vlen) static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen) { return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); } #define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \ xfs_attr_leaf_entsize_local_max(bsize) static inline int xfs_attr_leaf_entsize_local_max(int bsize) { return (((bsize) >> 1) + ((bsize) >> 2)); } /*======================================================================== * 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 attribute fork size < XFS_LITINO(mp). */ void xfs_attr_shortform_create(struct xfs_da_args *args); void xfs_attr_shortform_add(struct xfs_da_args *args, int forkoff); 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 *args); int xfs_attr_shortform_list(struct xfs_attr_list_context *context); int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp); int xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes); /* * Internal routines when attribute fork size == 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 forkoff); 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_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); /* * 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(int namelen, int valuelen, int blocksize, int *local); int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp); #endif /* __XFS_ATTR_LEAF_H__ */