forked from Minki/linux
ba0f32d460
SGI-PV: 936255 SGI-Modid: xfs-linux:xfs-kern:192760a Signed-off-by: Christoph Hellwig <hch@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
297 lines
12 KiB
C
297 lines
12 KiB
C
/*
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* Copyright (c) 2000, 2002-2003 Silicon Graphics, Inc. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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*
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* Further, this software is distributed without any warranty that it is
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* free of the rightful claim of any third person regarding infringement
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* or the like. Any license provided herein, whether implied or
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* otherwise, applies only to this software file. Patent licenses, if
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* any, provided herein do not apply to combinations of this program with
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* other software, or any other product whatsoever.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write the Free Software Foundation, Inc., 59
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* Temple Place - Suite 330, Boston MA 02111-1307, USA.
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*
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* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
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* Mountain View, CA 94043, or:
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*
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* http://www.sgi.com
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*
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* For further information regarding this notice, see:
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*
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* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
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*/
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#ifndef __XFS_ATTR_LEAF_H__
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#define __XFS_ATTR_LEAF_H__
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/*
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* Attribute storage layout, internal structure, access macros, etc.
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*
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* Attribute lists are structured around Btrees where all the data
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* elements are in the leaf nodes. Attribute names are hashed into an int,
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* then that int is used as the index into the Btree. Since the hashval
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* of an attribute name may not be unique, we may have duplicate keys. The
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* internal links in the Btree are logical block offsets into the file.
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*/
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struct attrlist;
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struct attrlist_cursor_kern;
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struct attrnames;
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struct xfs_dabuf;
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struct xfs_da_args;
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struct xfs_da_state;
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struct xfs_da_state_blk;
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struct xfs_inode;
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struct xfs_trans;
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/*========================================================================
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* Attribute structure when equal to XFS_LBSIZE(mp) bytes.
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*========================================================================*/
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/*
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* This is the structure of the leaf nodes in the Btree.
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*
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* Struct leaf_entry's are packed from the top. Name/values grow from the
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* bottom but are not packed. The freemap contains run-length-encoded entries
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* for the free bytes after the leaf_entry's, but only the N largest such,
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* smaller runs are dropped. When the freemap doesn't show enough space
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* for an allocation, we compact the name/value area and try again. If we
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* still don't have enough space, then we have to split the block. The
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* name/value structs (both local and remote versions) must be 32bit aligned.
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*
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* Since we have duplicate hash keys, for each key that matches, compare
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* the actual name string. The root and intermediate node search always
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* takes the first-in-the-block key match found, so we should only have
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* to work "forw"ard. If none matches, continue with the "forw"ard leaf
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* nodes until the hash key changes or the attribute name is found.
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*
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* We store the fact that an attribute is a ROOT/USER/SECURE attribute in
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* the leaf_entry. The namespaces are independent only because we also look
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* at the namespace bit when we are looking for a matching attribute name.
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*
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* We also store a "incomplete" bit in the leaf_entry. It shows that an
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* attribute is in the middle of being created and should not be shown to
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* the user if we crash during the time that the bit is set. We clear the
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* bit when we have finished setting up the attribute. We do this because
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* we cannot create some large attributes inside a single transaction, and we
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* need some indication that we weren't finished if we crash in the middle.
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*/
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#define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */
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typedef struct xfs_attr_leafblock {
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struct xfs_attr_leaf_hdr { /* constant-structure header block */
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xfs_da_blkinfo_t info; /* block type, links, etc. */
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__uint16_t count; /* count of active leaf_entry's */
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__uint16_t usedbytes; /* num bytes of names/values stored */
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__uint16_t firstused; /* first used byte in name area */
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__uint8_t holes; /* != 0 if blk needs compaction */
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__uint8_t pad1;
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struct xfs_attr_leaf_map { /* RLE map of free bytes */
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__uint16_t base; /* base of free region */
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__uint16_t size; /* length of free region */
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} freemap[XFS_ATTR_LEAF_MAPSIZE]; /* N largest free regions */
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} hdr;
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struct xfs_attr_leaf_entry { /* sorted on key, not name */
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xfs_dahash_t hashval; /* hash value of name */
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__uint16_t nameidx; /* index into buffer of name/value */
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__uint8_t flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
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__uint8_t pad2; /* unused pad byte */
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} entries[1]; /* variable sized array */
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struct xfs_attr_leaf_name_local {
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__uint16_t valuelen; /* number of bytes in value */
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__uint8_t namelen; /* length of name bytes */
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__uint8_t nameval[1]; /* name/value bytes */
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} namelist; /* grows from bottom of buf */
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struct xfs_attr_leaf_name_remote {
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xfs_dablk_t valueblk; /* block number of value bytes */
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__uint32_t valuelen; /* number of bytes in value */
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__uint8_t namelen; /* length of name bytes */
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__uint8_t name[1]; /* name bytes */
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} valuelist; /* grows from bottom of buf */
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} xfs_attr_leafblock_t;
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typedef struct xfs_attr_leaf_hdr xfs_attr_leaf_hdr_t;
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typedef struct xfs_attr_leaf_map xfs_attr_leaf_map_t;
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typedef struct xfs_attr_leaf_entry xfs_attr_leaf_entry_t;
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typedef struct xfs_attr_leaf_name_local xfs_attr_leaf_name_local_t;
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typedef struct xfs_attr_leaf_name_remote xfs_attr_leaf_name_remote_t;
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/*
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* Flags used in the leaf_entry[i].flags field.
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* NOTE: the INCOMPLETE bit must not collide with the flags bits specified
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* on the system call, they are "or"ed together for various operations.
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*/
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#define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */
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#define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */
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#define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */
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#define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
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#define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT)
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#define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
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#define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
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#define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
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/*
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* Alignment for namelist and valuelist entries (since they are mixed
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* there can be only one alignment value)
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*/
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#define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t))
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/*
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* Cast typed pointers for "local" and "remote" name/value structs.
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*/
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#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_REMOTE)
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xfs_attr_leaf_name_remote_t *
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xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx);
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#define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \
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xfs_attr_leaf_name_remote(leafp,idx)
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#else
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#define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) /* remote name struct ptr */ \
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((xfs_attr_leaf_name_remote_t *) \
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&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ])
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#endif
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#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_LOCAL)
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xfs_attr_leaf_name_local_t *
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xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx);
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#define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \
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xfs_attr_leaf_name_local(leafp,idx)
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#else
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#define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) /* local name struct ptr */ \
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((xfs_attr_leaf_name_local_t *) \
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&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ])
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#endif
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#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME)
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char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx);
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#define XFS_ATTR_LEAF_NAME(leafp,idx) xfs_attr_leaf_name(leafp,idx)
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#else
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#define XFS_ATTR_LEAF_NAME(leafp,idx) /* generic name struct ptr */ \
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(&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ])
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#endif
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/*
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* Calculate total bytes used (including trailing pad for alignment) for
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* a "local" name/value structure, a "remote" name/value structure, and
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* a pointer which might be either.
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*/
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#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_REMOTE)
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int xfs_attr_leaf_entsize_remote(int nlen);
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#define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \
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xfs_attr_leaf_entsize_remote(nlen)
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#else
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#define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) /* space for remote struct */ \
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(((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \
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XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1))
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#endif
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#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL)
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int xfs_attr_leaf_entsize_local(int nlen, int vlen);
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#define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \
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xfs_attr_leaf_entsize_local(nlen,vlen)
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#else
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#define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) /* space for local struct */ \
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(((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + \
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XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1))
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#endif
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#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX)
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int xfs_attr_leaf_entsize_local_max(int bsize);
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#define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \
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xfs_attr_leaf_entsize_local_max(bsize)
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#else
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#define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) /* max local struct size */ \
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(((bsize) >> 1) + ((bsize) >> 2))
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#endif
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/*========================================================================
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* Structure used to pass context around among the routines.
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*========================================================================*/
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typedef struct xfs_attr_list_context {
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struct xfs_inode *dp; /* inode */
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struct attrlist_cursor_kern *cursor;/* position in list */
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struct attrlist *alist; /* output buffer */
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int count; /* num used entries */
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int dupcnt; /* count dup hashvals seen */
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int bufsize;/* total buffer size */
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int firstu; /* first used byte in buffer */
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int flags; /* from VOP call */
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int resynch;/* T/F: resynch with cursor */
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} xfs_attr_list_context_t;
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/*
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* Used to keep a list of "remote value" extents when unlinking an inode.
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*/
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typedef struct xfs_attr_inactive_list {
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xfs_dablk_t valueblk; /* block number of value bytes */
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int valuelen; /* number of bytes in value */
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} xfs_attr_inactive_list_t;
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/*========================================================================
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* Function prototypes for the kernel.
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*========================================================================*/
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/*
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* Internal routines when dirsize < XFS_LITINO(mp).
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*/
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int xfs_attr_shortform_create(struct xfs_da_args *args);
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int xfs_attr_shortform_add(struct xfs_da_args *add);
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int xfs_attr_shortform_lookup(struct xfs_da_args *args);
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int xfs_attr_shortform_getvalue(struct xfs_da_args *args);
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int xfs_attr_shortform_to_leaf(struct xfs_da_args *args);
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int xfs_attr_shortform_remove(struct xfs_da_args *remove);
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int xfs_attr_shortform_list(struct xfs_attr_list_context *context);
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int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp);
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/*
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* Internal routines when dirsize == XFS_LBSIZE(mp).
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*/
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int xfs_attr_leaf_to_node(struct xfs_da_args *args);
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int xfs_attr_leaf_to_shortform(struct xfs_dabuf *bp,
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struct xfs_da_args *args);
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int xfs_attr_leaf_clearflag(struct xfs_da_args *args);
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int xfs_attr_leaf_setflag(struct xfs_da_args *args);
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int xfs_attr_leaf_flipflags(xfs_da_args_t *args);
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/*
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* Routines used for growing the Btree.
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*/
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int xfs_attr_leaf_split(struct xfs_da_state *state,
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struct xfs_da_state_blk *oldblk,
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struct xfs_da_state_blk *newblk);
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int xfs_attr_leaf_lookup_int(struct xfs_dabuf *leaf,
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struct xfs_da_args *args);
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int xfs_attr_leaf_getvalue(struct xfs_dabuf *bp, struct xfs_da_args *args);
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int xfs_attr_leaf_add(struct xfs_dabuf *leaf_buffer,
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struct xfs_da_args *args);
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int xfs_attr_leaf_remove(struct xfs_dabuf *leaf_buffer,
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struct xfs_da_args *args);
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int xfs_attr_leaf_list_int(struct xfs_dabuf *bp,
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struct xfs_attr_list_context *context);
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/*
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* Routines used for shrinking the Btree.
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*/
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int xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval);
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void xfs_attr_leaf_unbalance(struct xfs_da_state *state,
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struct xfs_da_state_blk *drop_blk,
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struct xfs_da_state_blk *save_blk);
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int xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp);
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/*
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* Utility routines.
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*/
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xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_dabuf *bp, int *count);
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int xfs_attr_leaf_order(struct xfs_dabuf *leaf1_bp,
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struct xfs_dabuf *leaf2_bp);
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int xfs_attr_leaf_newentsize(struct xfs_da_args *args, int blocksize,
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int *local);
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int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp);
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#endif /* __XFS_ATTR_LEAF_H__ */
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