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Diffstat (limited to 'fs/xfs/xfs_dir2_data.c')
-rw-r--r--fs/xfs/xfs_dir2_data.c855
1 files changed, 855 insertions, 0 deletions
diff --git a/fs/xfs/xfs_dir2_data.c b/fs/xfs/xfs_dir2_data.c
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+++ b/fs/xfs/xfs_dir2_data.c
@@ -0,0 +1,855 @@
+/*
+ * Copyright (c) 2000-2002 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/
+ */
+
+/*
+ * xfs_dir2_data.c
+ * Core data block handling routines for XFS V2 directories.
+ * See xfs_dir2_data.h for data structures.
+ */
+
+#include "xfs.h"
+
+#include "xfs_macros.h"
+#include "xfs_types.h"
+#include "xfs_inum.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_dir.h"
+#include "xfs_dir2.h"
+#include "xfs_dmapi.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_attr_sf.h"
+#include "xfs_dir_sf.h"
+#include "xfs_dir2_sf.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir_leaf.h"
+#include "xfs_dir2_data.h"
+#include "xfs_dir2_leaf.h"
+#include "xfs_dir2_block.h"
+#include "xfs_error.h"
+
+#ifdef DEBUG
+/*
+ * Check the consistency of the data block.
+ * The input can also be a block-format directory.
+ * Pop an assert if we find anything bad.
+ */
+void
+xfs_dir2_data_check(
+ xfs_inode_t *dp, /* incore inode pointer */
+ xfs_dabuf_t *bp) /* data block's buffer */
+{
+ xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
+ xfs_dir2_data_free_t *bf; /* bestfree table */
+ xfs_dir2_block_tail_t *btp=NULL; /* block tail */
+ int count; /* count of entries found */
+ xfs_dir2_data_t *d; /* data block pointer */
+ xfs_dir2_data_entry_t *dep; /* data entry */
+ xfs_dir2_data_free_t *dfp; /* bestfree entry */
+ xfs_dir2_data_unused_t *dup; /* unused entry */
+ char *endp; /* end of useful data */
+ int freeseen; /* mask of bestfrees seen */
+ xfs_dahash_t hash; /* hash of current name */
+ int i; /* leaf index */
+ int lastfree; /* last entry was unused */
+ xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
+ xfs_mount_t *mp; /* filesystem mount point */
+ char *p; /* current data position */
+ int stale; /* count of stale leaves */
+
+ mp = dp->i_mount;
+ d = bp->data;
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ bf = d->hdr.bestfree;
+ p = (char *)d->u;
+ if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
+ btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
+ lep = XFS_DIR2_BLOCK_LEAF_P(btp);
+ endp = (char *)lep;
+ } else
+ endp = (char *)d + mp->m_dirblksize;
+ count = lastfree = freeseen = 0;
+ /*
+ * Account for zero bestfree entries.
+ */
+ if (!bf[0].length) {
+ ASSERT(!bf[0].offset);
+ freeseen |= 1 << 0;
+ }
+ if (!bf[1].length) {
+ ASSERT(!bf[1].offset);
+ freeseen |= 1 << 1;
+ }
+ if (!bf[2].length) {
+ ASSERT(!bf[2].offset);
+ freeseen |= 1 << 2;
+ }
+ ASSERT(INT_GET(bf[0].length, ARCH_CONVERT) >= INT_GET(bf[1].length, ARCH_CONVERT));
+ ASSERT(INT_GET(bf[1].length, ARCH_CONVERT) >= INT_GET(bf[2].length, ARCH_CONVERT));
+ /*
+ * Loop over the data/unused entries.
+ */
+ while (p < endp) {
+ dup = (xfs_dir2_data_unused_t *)p;
+ /*
+ * If it's unused, look for the space in the bestfree table.
+ * If we find it, account for that, else make sure it
+ * doesn't need to be there.
+ */
+ if (INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG) {
+ ASSERT(lastfree == 0);
+ ASSERT(INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT) ==
+ (char *)dup - (char *)d);
+ dfp = xfs_dir2_data_freefind(d, dup);
+ if (dfp) {
+ i = (int)(dfp - bf);
+ ASSERT((freeseen & (1 << i)) == 0);
+ freeseen |= 1 << i;
+ } else
+ ASSERT(INT_GET(dup->length, ARCH_CONVERT) <= INT_GET(bf[2].length, ARCH_CONVERT));
+ p += INT_GET(dup->length, ARCH_CONVERT);
+ lastfree = 1;
+ continue;
+ }
+ /*
+ * It's a real entry. Validate the fields.
+ * If this is a block directory then make sure it's
+ * in the leaf section of the block.
+ * The linear search is crude but this is DEBUG code.
+ */
+ dep = (xfs_dir2_data_entry_t *)p;
+ ASSERT(dep->namelen != 0);
+ ASSERT(xfs_dir_ino_validate(mp, INT_GET(dep->inumber, ARCH_CONVERT)) == 0);
+ ASSERT(INT_GET(*XFS_DIR2_DATA_ENTRY_TAG_P(dep), ARCH_CONVERT) ==
+ (char *)dep - (char *)d);
+ count++;
+ lastfree = 0;
+ if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
+ addr = XFS_DIR2_DB_OFF_TO_DATAPTR(mp, mp->m_dirdatablk,
+ (xfs_dir2_data_aoff_t)
+ ((char *)dep - (char *)d));
+ hash = xfs_da_hashname((char *)dep->name, dep->namelen);
+ for (i = 0; i < INT_GET(btp->count, ARCH_CONVERT); i++) {
+ if (INT_GET(lep[i].address, ARCH_CONVERT) == addr &&
+ INT_GET(lep[i].hashval, ARCH_CONVERT) == hash)
+ break;
+ }
+ ASSERT(i < INT_GET(btp->count, ARCH_CONVERT));
+ }
+ p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
+ }
+ /*
+ * Need to have seen all the entries and all the bestfree slots.
+ */
+ ASSERT(freeseen == 7);
+ if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
+ for (i = stale = 0; i < INT_GET(btp->count, ARCH_CONVERT); i++) {
+ if (INT_GET(lep[i].address, ARCH_CONVERT) == XFS_DIR2_NULL_DATAPTR)
+ stale++;
+ if (i > 0)
+ ASSERT(INT_GET(lep[i].hashval, ARCH_CONVERT) >= INT_GET(lep[i - 1].hashval, ARCH_CONVERT));
+ }
+ ASSERT(count == INT_GET(btp->count, ARCH_CONVERT) - INT_GET(btp->stale, ARCH_CONVERT));
+ ASSERT(stale == INT_GET(btp->stale, ARCH_CONVERT));
+ }
+}
+#endif
+
+/*
+ * Given a data block and an unused entry from that block,
+ * return the bestfree entry if any that corresponds to it.
+ */
+xfs_dir2_data_free_t *
+xfs_dir2_data_freefind(
+ xfs_dir2_data_t *d, /* data block */
+ xfs_dir2_data_unused_t *dup) /* data unused entry */
+{
+ xfs_dir2_data_free_t *dfp; /* bestfree entry */
+ xfs_dir2_data_aoff_t off; /* offset value needed */
+#if defined(DEBUG) && defined(__KERNEL__)
+ int matched; /* matched the value */
+ int seenzero; /* saw a 0 bestfree entry */
+#endif
+
+ off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)d);
+#if defined(DEBUG) && defined(__KERNEL__)
+ /*
+ * Validate some consistency in the bestfree table.
+ * Check order, non-overlapping entries, and if we find the
+ * one we're looking for it has to be exact.
+ */
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ for (dfp = &d->hdr.bestfree[0], seenzero = matched = 0;
+ dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
+ dfp++) {
+ if (!dfp->offset) {
+ ASSERT(!dfp->length);
+ seenzero = 1;
+ continue;
+ }
+ ASSERT(seenzero == 0);
+ if (INT_GET(dfp->offset, ARCH_CONVERT) == off) {
+ matched = 1;
+ ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(dup->length, ARCH_CONVERT));
+ } else if (off < INT_GET(dfp->offset, ARCH_CONVERT))
+ ASSERT(off + INT_GET(dup->length, ARCH_CONVERT) <= INT_GET(dfp->offset, ARCH_CONVERT));
+ else
+ ASSERT(INT_GET(dfp->offset, ARCH_CONVERT) + INT_GET(dfp->length, ARCH_CONVERT) <= off);
+ ASSERT(matched || INT_GET(dfp->length, ARCH_CONVERT) >= INT_GET(dup->length, ARCH_CONVERT));
+ if (dfp > &d->hdr.bestfree[0])
+ ASSERT(INT_GET(dfp[-1].length, ARCH_CONVERT) >= INT_GET(dfp[0].length, ARCH_CONVERT));
+ }
+#endif
+ /*
+ * If this is smaller than the smallest bestfree entry,
+ * it can't be there since they're sorted.
+ */
+ if (INT_GET(dup->length, ARCH_CONVERT) < INT_GET(d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length, ARCH_CONVERT))
+ return NULL;
+ /*
+ * Look at the three bestfree entries for our guy.
+ */
+ for (dfp = &d->hdr.bestfree[0];
+ dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
+ dfp++) {
+ if (!dfp->offset)
+ return NULL;
+ if (INT_GET(dfp->offset, ARCH_CONVERT) == off)
+ return dfp;
+ }
+ /*
+ * Didn't find it. This only happens if there are duplicate lengths.
+ */
+ return NULL;
+}
+
+/*
+ * Insert an unused-space entry into the bestfree table.
+ */
+xfs_dir2_data_free_t * /* entry inserted */
+xfs_dir2_data_freeinsert(
+ xfs_dir2_data_t *d, /* data block pointer */
+ xfs_dir2_data_unused_t *dup, /* unused space */
+ int *loghead) /* log the data header (out) */
+{
+ xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
+ xfs_dir2_data_free_t new; /* new bestfree entry */
+
+#ifdef __KERNEL__
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+#endif
+ dfp = d->hdr.bestfree;
+ INT_COPY(new.length, dup->length, ARCH_CONVERT);
+ INT_SET(new.offset, ARCH_CONVERT, (xfs_dir2_data_off_t)((char *)dup - (char *)d));
+ /*
+ * Insert at position 0, 1, or 2; or not at all.
+ */
+ if (INT_GET(new.length, ARCH_CONVERT) > INT_GET(dfp[0].length, ARCH_CONVERT)) {
+ dfp[2] = dfp[1];
+ dfp[1] = dfp[0];
+ dfp[0] = new;
+ *loghead = 1;
+ return &dfp[0];
+ }
+ if (INT_GET(new.length, ARCH_CONVERT) > INT_GET(dfp[1].length, ARCH_CONVERT)) {
+ dfp[2] = dfp[1];
+ dfp[1] = new;
+ *loghead = 1;
+ return &dfp[1];
+ }
+ if (INT_GET(new.length, ARCH_CONVERT) > INT_GET(dfp[2].length, ARCH_CONVERT)) {
+ dfp[2] = new;
+ *loghead = 1;
+ return &dfp[2];
+ }
+ return NULL;
+}
+
+/*
+ * Remove a bestfree entry from the table.
+ */
+void
+xfs_dir2_data_freeremove(
+ xfs_dir2_data_t *d, /* data block pointer */
+ xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
+ int *loghead) /* out: log data header */
+{
+#ifdef __KERNEL__
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+#endif
+ /*
+ * It's the first entry, slide the next 2 up.
+ */
+ if (dfp == &d->hdr.bestfree[0]) {
+ d->hdr.bestfree[0] = d->hdr.bestfree[1];
+ d->hdr.bestfree[1] = d->hdr.bestfree[2];
+ }
+ /*
+ * It's the second entry, slide the 3rd entry up.
+ */
+ else if (dfp == &d->hdr.bestfree[1])
+ d->hdr.bestfree[1] = d->hdr.bestfree[2];
+ /*
+ * Must be the last entry.
+ */
+ else
+ ASSERT(dfp == &d->hdr.bestfree[2]);
+ /*
+ * Clear the 3rd entry, must be zero now.
+ */
+ d->hdr.bestfree[2].length = 0;
+ d->hdr.bestfree[2].offset = 0;
+ *loghead = 1;
+}
+
+/*
+ * Given a data block, reconstruct its bestfree map.
+ */
+void
+xfs_dir2_data_freescan(
+ xfs_mount_t *mp, /* filesystem mount point */
+ xfs_dir2_data_t *d, /* data block pointer */
+ int *loghead, /* out: log data header */
+ char *aendp) /* in: caller's endp */
+{
+ xfs_dir2_block_tail_t *btp; /* block tail */
+ xfs_dir2_data_entry_t *dep; /* active data entry */
+ xfs_dir2_data_unused_t *dup; /* unused data entry */
+ char *endp; /* end of block's data */
+ char *p; /* current entry pointer */
+
+#ifdef __KERNEL__
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+#endif
+ /*
+ * Start by clearing the table.
+ */
+ memset(d->hdr.bestfree, 0, sizeof(d->hdr.bestfree));
+ *loghead = 1;
+ /*
+ * Set up pointers.
+ */
+ p = (char *)d->u;
+ if (aendp)
+ endp = aendp;
+ else if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
+ btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
+ endp = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
+ } else
+ endp = (char *)d + mp->m_dirblksize;
+ /*
+ * Loop over the block's entries.
+ */
+ while (p < endp) {
+ dup = (xfs_dir2_data_unused_t *)p;
+ /*
+ * If it's a free entry, insert it.
+ */
+ if (INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG) {
+ ASSERT((char *)dup - (char *)d ==
+ INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT));
+ xfs_dir2_data_freeinsert(d, dup, loghead);
+ p += INT_GET(dup->length, ARCH_CONVERT);
+ }
+ /*
+ * For active entries, check their tags and skip them.
+ */
+ else {
+ dep = (xfs_dir2_data_entry_t *)p;
+ ASSERT((char *)dep - (char *)d ==
+ INT_GET(*XFS_DIR2_DATA_ENTRY_TAG_P(dep), ARCH_CONVERT));
+ p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
+ }
+ }
+}
+
+/*
+ * Initialize a data block at the given block number in the directory.
+ * Give back the buffer for the created block.
+ */
+int /* error */
+xfs_dir2_data_init(
+ xfs_da_args_t *args, /* directory operation args */
+ xfs_dir2_db_t blkno, /* logical dir block number */
+ xfs_dabuf_t **bpp) /* output block buffer */
+{
+ xfs_dabuf_t *bp; /* block buffer */
+ xfs_dir2_data_t *d; /* pointer to block */
+ xfs_inode_t *dp; /* incore directory inode */
+ xfs_dir2_data_unused_t *dup; /* unused entry pointer */
+ int error; /* error return value */
+ int i; /* bestfree index */
+ xfs_mount_t *mp; /* filesystem mount point */
+ xfs_trans_t *tp; /* transaction pointer */
+ int t; /* temp */
+
+ dp = args->dp;
+ mp = dp->i_mount;
+ tp = args->trans;
+ /*
+ * Get the buffer set up for the block.
+ */
+ error = xfs_da_get_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, blkno), -1, &bp,
+ XFS_DATA_FORK);
+ if (error) {
+ return error;
+ }
+ ASSERT(bp != NULL);
+ /*
+ * Initialize the header.
+ */
+ d = bp->data;
+ INT_SET(d->hdr.magic, ARCH_CONVERT, XFS_DIR2_DATA_MAGIC);
+ INT_SET(d->hdr.bestfree[0].offset, ARCH_CONVERT, (xfs_dir2_data_off_t)sizeof(d->hdr));
+ for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
+ d->hdr.bestfree[i].length = 0;
+ d->hdr.bestfree[i].offset = 0;
+ }
+ /*
+ * Set up an unused entry for the block's body.
+ */
+ dup = &d->u[0].unused;
+ INT_SET(dup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
+
+ t=mp->m_dirblksize - (uint)sizeof(d->hdr);
+ INT_SET(d->hdr.bestfree[0].length, ARCH_CONVERT, t);
+ INT_SET(dup->length, ARCH_CONVERT, t);
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)dup - (char *)d));
+ /*
+ * Log it and return it.
+ */
+ xfs_dir2_data_log_header(tp, bp);
+ xfs_dir2_data_log_unused(tp, bp, dup);
+ *bpp = bp;
+ return 0;
+}
+
+/*
+ * Log an active data entry from the block.
+ */
+void
+xfs_dir2_data_log_entry(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_dabuf_t *bp, /* block buffer */
+ xfs_dir2_data_entry_t *dep) /* data entry pointer */
+{
+ xfs_dir2_data_t *d; /* data block pointer */
+
+ d = bp->data;
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)d),
+ (uint)((char *)(XFS_DIR2_DATA_ENTRY_TAG_P(dep) + 1) -
+ (char *)d - 1));
+}
+
+/*
+ * Log a data block header.
+ */
+void
+xfs_dir2_data_log_header(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_dabuf_t *bp) /* block buffer */
+{
+ xfs_dir2_data_t *d; /* data block pointer */
+
+ d = bp->data;
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ xfs_da_log_buf(tp, bp, (uint)((char *)&d->hdr - (char *)d),
+ (uint)(sizeof(d->hdr) - 1));
+}
+
+/*
+ * Log a data unused entry.
+ */
+void
+xfs_dir2_data_log_unused(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_dabuf_t *bp, /* block buffer */
+ xfs_dir2_data_unused_t *dup) /* data unused pointer */
+{
+ xfs_dir2_data_t *d; /* data block pointer */
+
+ d = bp->data;
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ /*
+ * Log the first part of the unused entry.
+ */
+ xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)d),
+ (uint)((char *)&dup->length + sizeof(dup->length) -
+ 1 - (char *)d));
+ /*
+ * Log the end (tag) of the unused entry.
+ */
+ xfs_da_log_buf(tp, bp,
+ (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d),
+ (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d +
+ sizeof(xfs_dir2_data_off_t) - 1));
+}
+
+/*
+ * Make a byte range in the data block unused.
+ * Its current contents are unimportant.
+ */
+void
+xfs_dir2_data_make_free(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_dabuf_t *bp, /* block buffer */
+ xfs_dir2_data_aoff_t offset, /* starting byte offset */
+ xfs_dir2_data_aoff_t len, /* length in bytes */
+ int *needlogp, /* out: log header */
+ int *needscanp) /* out: regen bestfree */
+{
+ xfs_dir2_data_t *d; /* data block pointer */
+ xfs_dir2_data_free_t *dfp; /* bestfree pointer */
+ char *endptr; /* end of data area */
+ xfs_mount_t *mp; /* filesystem mount point */
+ int needscan; /* need to regen bestfree */
+ xfs_dir2_data_unused_t *newdup; /* new unused entry */
+ xfs_dir2_data_unused_t *postdup; /* unused entry after us */
+ xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
+
+ mp = tp->t_mountp;
+ d = bp->data;
+ /*
+ * Figure out where the end of the data area is.
+ */
+ if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC)
+ endptr = (char *)d + mp->m_dirblksize;
+ else {
+ xfs_dir2_block_tail_t *btp; /* block tail */
+
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
+ endptr = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
+ }
+ /*
+ * If this isn't the start of the block, then back up to
+ * the previous entry and see if it's free.
+ */
+ if (offset > sizeof(d->hdr)) {
+ xfs_dir2_data_off_t *tagp; /* tag just before us */
+
+ tagp = (xfs_dir2_data_off_t *)((char *)d + offset) - 1;
+ prevdup = (xfs_dir2_data_unused_t *)((char *)d + INT_GET(*tagp, ARCH_CONVERT));
+ if (INT_GET(prevdup->freetag, ARCH_CONVERT) != XFS_DIR2_DATA_FREE_TAG)
+ prevdup = NULL;
+ } else
+ prevdup = NULL;
+ /*
+ * If this isn't the end of the block, see if the entry after
+ * us is free.
+ */
+ if ((char *)d + offset + len < endptr) {
+ postdup =
+ (xfs_dir2_data_unused_t *)((char *)d + offset + len);
+ if (INT_GET(postdup->freetag, ARCH_CONVERT) != XFS_DIR2_DATA_FREE_TAG)
+ postdup = NULL;
+ } else
+ postdup = NULL;
+ ASSERT(*needscanp == 0);
+ needscan = 0;
+ /*
+ * Previous and following entries are both free,
+ * merge everything into a single free entry.
+ */
+ if (prevdup && postdup) {
+ xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
+
+ /*
+ * See if prevdup and/or postdup are in bestfree table.
+ */
+ dfp = xfs_dir2_data_freefind(d, prevdup);
+ dfp2 = xfs_dir2_data_freefind(d, postdup);
+ /*
+ * We need a rescan unless there are exactly 2 free entries
+ * namely our two. Then we know what's happening, otherwise
+ * since the third bestfree is there, there might be more
+ * entries.
+ */
+ needscan = d->hdr.bestfree[2].length;
+ /*
+ * Fix up the new big freespace.
+ */
+ INT_MOD(prevdup->length, ARCH_CONVERT, len + INT_GET(postdup->length, ARCH_CONVERT));
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(prevdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)prevdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, prevdup);
+ if (!needscan) {
+ /*
+ * Has to be the case that entries 0 and 1 are
+ * dfp and dfp2 (don't know which is which), and
+ * entry 2 is empty.
+ * Remove entry 1 first then entry 0.
+ */
+ ASSERT(dfp && dfp2);
+ if (dfp == &d->hdr.bestfree[1]) {
+ dfp = &d->hdr.bestfree[0];
+ ASSERT(dfp2 == dfp);
+ dfp2 = &d->hdr.bestfree[1];
+ }
+ xfs_dir2_data_freeremove(d, dfp2, needlogp);
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ /*
+ * Now insert the new entry.
+ */
+ dfp = xfs_dir2_data_freeinsert(d, prevdup, needlogp);
+ ASSERT(dfp == &d->hdr.bestfree[0]);
+ ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(prevdup->length, ARCH_CONVERT));
+ ASSERT(!dfp[1].length);
+ ASSERT(!dfp[2].length);
+ }
+ }
+ /*
+ * The entry before us is free, merge with it.
+ */
+ else if (prevdup) {
+ dfp = xfs_dir2_data_freefind(d, prevdup);
+ INT_MOD(prevdup->length, ARCH_CONVERT, len);
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(prevdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)prevdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, prevdup);
+ /*
+ * If the previous entry was in the table, the new entry
+ * is longer, so it will be in the table too. Remove
+ * the old one and add the new one.
+ */
+ if (dfp) {
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ (void)xfs_dir2_data_freeinsert(d, prevdup, needlogp);
+ }
+ /*
+ * Otherwise we need a scan if the new entry is big enough.
+ */
+ else
+ needscan = INT_GET(prevdup->length, ARCH_CONVERT) > INT_GET(d->hdr.bestfree[2].length, ARCH_CONVERT);
+ }
+ /*
+ * The following entry is free, merge with it.
+ */
+ else if (postdup) {
+ dfp = xfs_dir2_data_freefind(d, postdup);
+ newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
+ INT_SET(newdup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
+ INT_SET(newdup->length, ARCH_CONVERT, len + INT_GET(postdup->length, ARCH_CONVERT));
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, newdup);
+ /*
+ * If the following entry was in the table, the new entry
+ * is longer, so it will be in the table too. Remove
+ * the old one and add the new one.
+ */
+ if (dfp) {
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
+ }
+ /*
+ * Otherwise we need a scan if the new entry is big enough.
+ */
+ else
+ needscan = INT_GET(newdup->length, ARCH_CONVERT) > INT_GET(d->hdr.bestfree[2].length, ARCH_CONVERT);
+ }
+ /*
+ * Neither neighbor is free. Make a new entry.
+ */
+ else {
+ newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
+ INT_SET(newdup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
+ INT_SET(newdup->length, ARCH_CONVERT, len);
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, newdup);
+ (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
+ }
+ *needscanp = needscan;
+}
+
+/*
+ * Take a byte range out of an existing unused space and make it un-free.
+ */
+void
+xfs_dir2_data_use_free(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_dabuf_t *bp, /* data block buffer */
+ xfs_dir2_data_unused_t *dup, /* unused entry */
+ xfs_dir2_data_aoff_t offset, /* starting offset to use */
+ xfs_dir2_data_aoff_t len, /* length to use */
+ int *needlogp, /* out: need to log header */
+ int *needscanp) /* out: need regen bestfree */
+{
+ xfs_dir2_data_t *d; /* data block */
+ xfs_dir2_data_free_t *dfp; /* bestfree pointer */
+ int matchback; /* matches end of freespace */
+ int matchfront; /* matches start of freespace */
+ int needscan; /* need to regen bestfree */
+ xfs_dir2_data_unused_t *newdup; /* new unused entry */
+ xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
+ int oldlen; /* old unused entry's length */
+
+ d = bp->data;
+ ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
+ INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
+ ASSERT(INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG);
+ ASSERT(offset >= (char *)dup - (char *)d);
+ ASSERT(offset + len <= (char *)dup + INT_GET(dup->length, ARCH_CONVERT) - (char *)d);
+ ASSERT((char *)dup - (char *)d == INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT));
+ /*
+ * Look up the entry in the bestfree table.
+ */
+ dfp = xfs_dir2_data_freefind(d, dup);
+ oldlen = INT_GET(dup->length, ARCH_CONVERT);
+ ASSERT(dfp || oldlen <= INT_GET(d->hdr.bestfree[2].length, ARCH_CONVERT));
+ /*
+ * Check for alignment with front and back of the entry.
+ */
+ matchfront = (char *)dup - (char *)d == offset;
+ matchback = (char *)dup + oldlen - (char *)d == offset + len;
+ ASSERT(*needscanp == 0);
+ needscan = 0;
+ /*
+ * If we matched it exactly we just need to get rid of it from
+ * the bestfree table.
+ */
+ if (matchfront && matchback) {
+ if (dfp) {
+ needscan = d->hdr.bestfree[2].offset;
+ if (!needscan)
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ }
+ }
+ /*
+ * We match the first part of the entry.
+ * Make a new entry with the remaining freespace.
+ */
+ else if (matchfront) {
+ newdup = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
+ INT_SET(newdup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
+ INT_SET(newdup->length, ARCH_CONVERT, oldlen - len);
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, newdup);
+ /*
+ * If it was in the table, remove it and add the new one.
+ */
+ if (dfp) {
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
+ ASSERT(dfp != NULL);
+ ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(newdup->length, ARCH_CONVERT));
+ ASSERT(INT_GET(dfp->offset, ARCH_CONVERT) == (char *)newdup - (char *)d);
+ /*
+ * If we got inserted at the last slot,
+ * that means we don't know if there was a better
+ * choice for the last slot, or not. Rescan.
+ */
+ needscan = dfp == &d->hdr.bestfree[2];
+ }
+ }
+ /*
+ * We match the last part of the entry.
+ * Trim the allocated space off the tail of the entry.
+ */
+ else if (matchback) {
+ newdup = dup;
+ INT_SET(newdup->length, ARCH_CONVERT, (xfs_dir2_data_off_t)
+ (((char *)d + offset) - (char *)newdup));
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, newdup);
+ /*
+ * If it was in the table, remove it and add the new one.
+ */
+ if (dfp) {
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
+ ASSERT(dfp != NULL);
+ ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(newdup->length, ARCH_CONVERT));
+ ASSERT(INT_GET(dfp->offset, ARCH_CONVERT) == (char *)newdup - (char *)d);
+ /*
+ * If we got inserted at the last slot,
+ * that means we don't know if there was a better
+ * choice for the last slot, or not. Rescan.
+ */
+ needscan = dfp == &d->hdr.bestfree[2];
+ }
+ }
+ /*
+ * Poking out the middle of an entry.
+ * Make two new entries.
+ */
+ else {
+ newdup = dup;
+ INT_SET(newdup->length, ARCH_CONVERT, (xfs_dir2_data_off_t)
+ (((char *)d + offset) - (char *)newdup));
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, newdup);
+ newdup2 = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
+ INT_SET(newdup2->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
+ INT_SET(newdup2->length, ARCH_CONVERT, oldlen - len - INT_GET(newdup->length, ARCH_CONVERT));
+ INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup2), ARCH_CONVERT,
+ (xfs_dir2_data_off_t)((char *)newdup2 - (char *)d));
+ xfs_dir2_data_log_unused(tp, bp, newdup2);
+ /*
+ * If the old entry was in the table, we need to scan
+ * if the 3rd entry was valid, since these entries
+ * are smaller than the old one.
+ * If we don't need to scan that means there were 1 or 2
+ * entries in the table, and removing the old and adding
+ * the 2 new will work.
+ */
+ if (dfp) {
+ needscan = d->hdr.bestfree[2].length;
+ if (!needscan) {
+ xfs_dir2_data_freeremove(d, dfp, needlogp);
+ (void)xfs_dir2_data_freeinsert(d, newdup,
+ needlogp);
+ (void)xfs_dir2_data_freeinsert(d, newdup2,
+ needlogp);
+ }
+ }
+ }
+ *needscanp = needscan;
+}