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+/*
+ * Copyright (c) 2000-2001 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_DIR_LEAF_H__
+#define __XFS_DIR_LEAF_H__
+
+/*
+ * Directory layout, internal structure, access macros, etc.
+ *
+ * Large directories are structured around Btrees where all the data
+ * elements are in the leaf nodes. Filenames are hashed into an int,
+ * then that int is used as the index into the Btree. Since the hashval
+ * of a filename may not be unique, we may have duplicate keys. The
+ * internal links in the Btree are logical block offsets into the file.
+ */
+
+struct uio;
+struct xfs_bmap_free;
+struct xfs_dabuf;
+struct xfs_da_args;
+struct xfs_da_state;
+struct xfs_da_state_blk;
+struct xfs_dir_put_args;
+struct xfs_inode;
+struct xfs_mount;
+struct xfs_trans;
+
+/*========================================================================
+ * Directory 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. Names 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 namelist area and try again. If we
+ * still don't have enough space, then we have to split the block.
+ *
+ * Since we have duplicate hash keys, for each key that matches, compare
+ * the actual 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 filename is found.
+ *
+ * The parent directory and the self-pointer are explicitly represented
+ * (ie: there are entries for "." and "..").
+ *
+ * Note that the count being a __uint16_t limits us to something like a
+ * blocksize of 1.3MB in the face of worst case (short) filenames.
+ */
+#define XFS_DIR_LEAF_MAPSIZE 3 /* how many freespace slots */
+
+typedef struct xfs_dir_leafblock {
+ struct xfs_dir_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 namebytes; /* num bytes of name strings stored */
+ __uint16_t firstused; /* first used byte in name area */
+ __uint8_t holes; /* != 0 if blk needs compaction */
+ __uint8_t pad1;
+ struct xfs_dir_leaf_map {/* RLE map of free bytes */
+ __uint16_t base; /* base of free region */
+ __uint16_t size; /* run length of free region */
+ } freemap[XFS_DIR_LEAF_MAPSIZE]; /* N largest free regions */
+ } hdr;
+ struct xfs_dir_leaf_entry { /* sorted on key, not name */
+ xfs_dahash_t hashval; /* hash value of name */
+ __uint16_t nameidx; /* index into buffer of name */
+ __uint8_t namelen; /* length of name string */
+ __uint8_t pad2;
+ } entries[1]; /* var sized array */
+ struct xfs_dir_leaf_name {
+ xfs_dir_ino_t inumber; /* inode number for this key */
+ __uint8_t name[1]; /* name string itself */
+ } namelist[1]; /* grows from bottom of buf */
+} xfs_dir_leafblock_t;
+typedef struct xfs_dir_leaf_hdr xfs_dir_leaf_hdr_t;
+typedef struct xfs_dir_leaf_map xfs_dir_leaf_map_t;
+typedef struct xfs_dir_leaf_entry xfs_dir_leaf_entry_t;
+typedef struct xfs_dir_leaf_name xfs_dir_leaf_name_t;
+
+/*
+ * Length of name for which a 512-byte block filesystem
+ * can get a double split.
+ */
+#define XFS_DIR_LEAF_CAN_DOUBLE_SPLIT_LEN \
+ (512 - (uint)sizeof(xfs_dir_leaf_hdr_t) - \
+ (uint)sizeof(xfs_dir_leaf_entry_t) * 2 - \
+ (uint)sizeof(xfs_dir_leaf_name_t) * 2 - (MAXNAMELEN - 2) + 1 + 1)
+
+typedef int (*xfs_dir_put_t)(struct xfs_dir_put_args *pa);
+
+typedef union {
+ xfs_off_t o; /* offset (cookie) */
+ /*
+ * Watch the order here (endian-ness dependent).
+ */
+ struct {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ xfs_dahash_t h; /* hash value */
+ __uint32_t be; /* block and entry */
+#else /* __BYTE_ORDER == __BIG_ENDIAN */
+ __uint32_t be; /* block and entry */
+ xfs_dahash_t h; /* hash value */
+#endif /* __BYTE_ORDER == __BIG_ENDIAN */
+ } s;
+} xfs_dircook_t;
+
+#define XFS_PUT_COOKIE(c,mp,bno,entry,hash) \
+ ((c).s.be = XFS_DA_MAKE_BNOENTRY(mp, bno, entry), (c).s.h = (hash))
+
+typedef struct xfs_dir_put_args
+{
+ xfs_dircook_t cook; /* cookie of (next) entry */
+ xfs_intino_t ino; /* inode number */
+ struct xfs_dirent *dbp; /* buffer pointer */
+ char *name; /* directory entry name */
+ int namelen; /* length of name */
+ int done; /* output: set if value was stored */
+ xfs_dir_put_t put; /* put function ptr (i/o) */
+ struct uio *uio; /* uio control structure */
+} xfs_dir_put_args_t;
+
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR_LEAF_ENTSIZE_BYNAME)
+int xfs_dir_leaf_entsize_byname(int len);
+#define XFS_DIR_LEAF_ENTSIZE_BYNAME(len) xfs_dir_leaf_entsize_byname(len)
+#else
+#define XFS_DIR_LEAF_ENTSIZE_BYNAME(len) /* space a name will use */ \
+ ((uint)sizeof(xfs_dir_leaf_name_t)-1 + len)
+#endif
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR_LEAF_ENTSIZE_BYENTRY)
+int xfs_dir_leaf_entsize_byentry(xfs_dir_leaf_entry_t *entry);
+#define XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry) \
+ xfs_dir_leaf_entsize_byentry(entry)
+#else
+#define XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry) /* space an entry will use */ \
+ ((uint)sizeof(xfs_dir_leaf_name_t)-1 + (entry)->namelen)
+#endif
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR_LEAF_NAMESTRUCT)
+xfs_dir_leaf_name_t *
+xfs_dir_leaf_namestruct(xfs_dir_leafblock_t *leafp, int offset);
+#define XFS_DIR_LEAF_NAMESTRUCT(leafp,offset) \
+ xfs_dir_leaf_namestruct(leafp,offset)
+#else
+#define XFS_DIR_LEAF_NAMESTRUCT(leafp,offset) /* point to name struct */ \
+ ((xfs_dir_leaf_name_t *)&((char *)(leafp))[offset])
+#endif
+
+/*========================================================================
+ * Function prototypes for the kernel.
+ *========================================================================*/
+
+/*
+ * Internal routines when dirsize < XFS_LITINO(mp).
+ */
+int xfs_dir_shortform_create(struct xfs_da_args *args, xfs_ino_t parent);
+int xfs_dir_shortform_addname(struct xfs_da_args *args);
+int xfs_dir_shortform_lookup(struct xfs_da_args *args);
+int xfs_dir_shortform_to_leaf(struct xfs_da_args *args);
+int xfs_dir_shortform_removename(struct xfs_da_args *args);
+int xfs_dir_shortform_getdents(struct xfs_inode *dp, struct uio *uio, int *eofp,
+ struct xfs_dirent *dbp, xfs_dir_put_t put);
+int xfs_dir_shortform_replace(struct xfs_da_args *args);
+
+/*
+ * Internal routines when dirsize == XFS_LBSIZE(mp).
+ */
+int xfs_dir_leaf_to_node(struct xfs_da_args *args);
+int xfs_dir_leaf_to_shortform(struct xfs_da_args *args);
+
+/*
+ * Routines used for growing the Btree.
+ */
+int xfs_dir_leaf_create(struct xfs_da_args *args, xfs_dablk_t which_block,
+ struct xfs_dabuf **bpp);
+int xfs_dir_leaf_split(struct xfs_da_state *state,
+ struct xfs_da_state_blk *oldblk,
+ struct xfs_da_state_blk *newblk);
+int xfs_dir_leaf_add(struct xfs_dabuf *leaf_buffer,
+ struct xfs_da_args *args, int insertion_index);
+int xfs_dir_leaf_addname(struct xfs_da_args *args);
+int xfs_dir_leaf_lookup_int(struct xfs_dabuf *leaf_buffer,
+ struct xfs_da_args *args,
+ int *index_found_at);
+int xfs_dir_leaf_remove(struct xfs_trans *trans,
+ struct xfs_dabuf *leaf_buffer,
+ int index_to_remove);
+int xfs_dir_leaf_getdents_int(struct xfs_dabuf *bp, struct xfs_inode *dp,
+ xfs_dablk_t bno, struct uio *uio,
+ int *eobp, struct xfs_dirent *dbp,
+ xfs_dir_put_t put, xfs_daddr_t nextda);
+
+/*
+ * Routines used for shrinking the Btree.
+ */
+int xfs_dir_leaf_toosmall(struct xfs_da_state *state, int *retval);
+void xfs_dir_leaf_unbalance(struct xfs_da_state *state,
+ struct xfs_da_state_blk *drop_blk,
+ struct xfs_da_state_blk *save_blk);
+
+/*
+ * Utility routines.
+ */
+uint xfs_dir_leaf_lasthash(struct xfs_dabuf *bp, int *count);
+int xfs_dir_leaf_order(struct xfs_dabuf *leaf1_bp,
+ struct xfs_dabuf *leaf2_bp);
+int xfs_dir_put_dirent64_direct(xfs_dir_put_args_t *pa);
+int xfs_dir_put_dirent64_uio(xfs_dir_put_args_t *pa);
+int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
+
+
+/*
+ * Global data.
+ */
+extern xfs_dahash_t xfs_dir_hash_dot, xfs_dir_hash_dotdot;
+
+#endif /* __XFS_DIR_LEAF_H__ */
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