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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/xfs/xfs_btree.c
downloadop-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/xfs/xfs_btree.c')
-rw-r--r--fs/xfs/xfs_btree.c949
1 files changed, 949 insertions, 0 deletions
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
new file mode 100644
index 0000000..9dd22dd
--- /dev/null
+++ b/fs/xfs/xfs_btree.c
@@ -0,0 +1,949 @@
+/*
+ * 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/
+ */
+
+/*
+ * This file contains common code for the space manager's btree implementations.
+ */
+
+#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_ag.h"
+#include "xfs_dir.h"
+#include "xfs_dir2.h"
+#include "xfs_dmapi.h"
+#include "xfs_mount.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_btree.h"
+#include "xfs_ialloc.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_bit.h"
+#include "xfs_error.h"
+
+/*
+ * Cursor allocation zone.
+ */
+kmem_zone_t *xfs_btree_cur_zone;
+
+/*
+ * Btree magic numbers.
+ */
+const __uint32_t xfs_magics[XFS_BTNUM_MAX] =
+{
+ XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
+};
+
+/*
+ * Prototypes for internal routines.
+ */
+
+/*
+ * Checking routine: return maxrecs for the block.
+ */
+STATIC int /* number of records fitting in block */
+xfs_btree_maxrecs(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_btree_block_t *block);/* generic btree block pointer */
+
+/*
+ * Internal routines.
+ */
+
+/*
+ * Checking routine: return maxrecs for the block.
+ */
+STATIC int /* number of records fitting in block */
+xfs_btree_maxrecs(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_btree_block_t *block) /* generic btree block pointer */
+{
+ switch (cur->bc_btnum) {
+ case XFS_BTNUM_BNO:
+ case XFS_BTNUM_CNT:
+ return (int)XFS_ALLOC_BLOCK_MAXRECS(INT_GET(block->bb_h.bb_level, ARCH_CONVERT), cur);
+ case XFS_BTNUM_BMAP:
+ return (int)XFS_BMAP_BLOCK_IMAXRECS(INT_GET(block->bb_h.bb_level, ARCH_CONVERT), cur);
+ case XFS_BTNUM_INO:
+ return (int)XFS_INOBT_BLOCK_MAXRECS(INT_GET(block->bb_h.bb_level, ARCH_CONVERT), cur);
+ default:
+ ASSERT(0);
+ return 0;
+ }
+}
+
+/*
+ * External routines.
+ */
+
+#ifdef DEBUG
+/*
+ * Debug routine: check that block header is ok.
+ */
+void
+xfs_btree_check_block(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_btree_block_t *block, /* generic btree block pointer */
+ int level, /* level of the btree block */
+ xfs_buf_t *bp) /* buffer containing block, if any */
+{
+ if (XFS_BTREE_LONG_PTRS(cur->bc_btnum))
+ xfs_btree_check_lblock(cur, (xfs_btree_lblock_t *)block, level,
+ bp);
+ else
+ xfs_btree_check_sblock(cur, (xfs_btree_sblock_t *)block, level,
+ bp);
+}
+
+/*
+ * Debug routine: check that keys are in the right order.
+ */
+void
+xfs_btree_check_key(
+ xfs_btnum_t btnum, /* btree identifier */
+ void *ak1, /* pointer to left (lower) key */
+ void *ak2) /* pointer to right (higher) key */
+{
+ switch (btnum) {
+ case XFS_BTNUM_BNO: {
+ xfs_alloc_key_t *k1;
+ xfs_alloc_key_t *k2;
+
+ k1 = ak1;
+ k2 = ak2;
+ ASSERT(INT_GET(k1->ar_startblock, ARCH_CONVERT) < INT_GET(k2->ar_startblock, ARCH_CONVERT));
+ break;
+ }
+ case XFS_BTNUM_CNT: {
+ xfs_alloc_key_t *k1;
+ xfs_alloc_key_t *k2;
+
+ k1 = ak1;
+ k2 = ak2;
+ ASSERT(INT_GET(k1->ar_blockcount, ARCH_CONVERT) < INT_GET(k2->ar_blockcount, ARCH_CONVERT) ||
+ (INT_GET(k1->ar_blockcount, ARCH_CONVERT) == INT_GET(k2->ar_blockcount, ARCH_CONVERT) &&
+ INT_GET(k1->ar_startblock, ARCH_CONVERT) < INT_GET(k2->ar_startblock, ARCH_CONVERT)));
+ break;
+ }
+ case XFS_BTNUM_BMAP: {
+ xfs_bmbt_key_t *k1;
+ xfs_bmbt_key_t *k2;
+
+ k1 = ak1;
+ k2 = ak2;
+ ASSERT(INT_GET(k1->br_startoff, ARCH_CONVERT) < INT_GET(k2->br_startoff, ARCH_CONVERT));
+ break;
+ }
+ case XFS_BTNUM_INO: {
+ xfs_inobt_key_t *k1;
+ xfs_inobt_key_t *k2;
+
+ k1 = ak1;
+ k2 = ak2;
+ ASSERT(INT_GET(k1->ir_startino, ARCH_CONVERT) < INT_GET(k2->ir_startino, ARCH_CONVERT));
+ break;
+ }
+ default:
+ ASSERT(0);
+ }
+}
+#endif /* DEBUG */
+
+/*
+ * Checking routine: check that long form block header is ok.
+ */
+/* ARGSUSED */
+int /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_lblock(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_btree_lblock_t *block, /* btree long form block pointer */
+ int level, /* level of the btree block */
+ xfs_buf_t *bp) /* buffer for block, if any */
+{
+ int lblock_ok; /* block passes checks */
+ xfs_mount_t *mp; /* file system mount point */
+
+ mp = cur->bc_mp;
+ lblock_ok =
+ INT_GET(block->bb_magic, ARCH_CONVERT) == xfs_magics[cur->bc_btnum] &&
+ INT_GET(block->bb_level, ARCH_CONVERT) == level &&
+ INT_GET(block->bb_numrecs, ARCH_CONVERT) <=
+ xfs_btree_maxrecs(cur, (xfs_btree_block_t *)block) &&
+ block->bb_leftsib &&
+ (INT_GET(block->bb_leftsib, ARCH_CONVERT) == NULLDFSBNO ||
+ XFS_FSB_SANITY_CHECK(mp, INT_GET(block->bb_leftsib, ARCH_CONVERT))) &&
+ block->bb_rightsib &&
+ (INT_GET(block->bb_rightsib, ARCH_CONVERT) == NULLDFSBNO ||
+ XFS_FSB_SANITY_CHECK(mp, INT_GET(block->bb_rightsib, ARCH_CONVERT)));
+ if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK,
+ XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
+ if (bp)
+ xfs_buftrace("LBTREE ERROR", bp);
+ XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
+ mp);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+ return 0;
+}
+
+/*
+ * Checking routine: check that (long) pointer is ok.
+ */
+int /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_lptr(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_dfsbno_t ptr, /* btree block disk address */
+ int level) /* btree block level */
+{
+ xfs_mount_t *mp; /* file system mount point */
+
+ mp = cur->bc_mp;
+ XFS_WANT_CORRUPTED_RETURN(
+ level > 0 &&
+ ptr != NULLDFSBNO &&
+ XFS_FSB_SANITY_CHECK(mp, ptr));
+ return 0;
+}
+
+#ifdef DEBUG
+/*
+ * Debug routine: check that records are in the right order.
+ */
+void
+xfs_btree_check_rec(
+ xfs_btnum_t btnum, /* btree identifier */
+ void *ar1, /* pointer to left (lower) record */
+ void *ar2) /* pointer to right (higher) record */
+{
+ switch (btnum) {
+ case XFS_BTNUM_BNO: {
+ xfs_alloc_rec_t *r1;
+ xfs_alloc_rec_t *r2;
+
+ r1 = ar1;
+ r2 = ar2;
+ ASSERT(INT_GET(r1->ar_startblock, ARCH_CONVERT) + INT_GET(r1->ar_blockcount, ARCH_CONVERT) <=
+ INT_GET(r2->ar_startblock, ARCH_CONVERT));
+ break;
+ }
+ case XFS_BTNUM_CNT: {
+ xfs_alloc_rec_t *r1;
+ xfs_alloc_rec_t *r2;
+
+ r1 = ar1;
+ r2 = ar2;
+ ASSERT(INT_GET(r1->ar_blockcount, ARCH_CONVERT) < INT_GET(r2->ar_blockcount, ARCH_CONVERT) ||
+ (INT_GET(r1->ar_blockcount, ARCH_CONVERT) == INT_GET(r2->ar_blockcount, ARCH_CONVERT) &&
+ INT_GET(r1->ar_startblock, ARCH_CONVERT) < INT_GET(r2->ar_startblock, ARCH_CONVERT)));
+ break;
+ }
+ case XFS_BTNUM_BMAP: {
+ xfs_bmbt_rec_t *r1;
+ xfs_bmbt_rec_t *r2;
+
+ r1 = ar1;
+ r2 = ar2;
+ ASSERT(xfs_bmbt_disk_get_startoff(r1) +
+ xfs_bmbt_disk_get_blockcount(r1) <=
+ xfs_bmbt_disk_get_startoff(r2));
+ break;
+ }
+ case XFS_BTNUM_INO: {
+ xfs_inobt_rec_t *r1;
+ xfs_inobt_rec_t *r2;
+
+ r1 = ar1;
+ r2 = ar2;
+ ASSERT(INT_GET(r1->ir_startino, ARCH_CONVERT) + XFS_INODES_PER_CHUNK <=
+ INT_GET(r2->ir_startino, ARCH_CONVERT));
+ break;
+ }
+ default:
+ ASSERT(0);
+ }
+}
+#endif /* DEBUG */
+
+/*
+ * Checking routine: check that block header is ok.
+ */
+/* ARGSUSED */
+int /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_sblock(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_btree_sblock_t *block, /* btree short form block pointer */
+ int level, /* level of the btree block */
+ xfs_buf_t *bp) /* buffer containing block */
+{
+ xfs_buf_t *agbp; /* buffer for ag. freespace struct */
+ xfs_agf_t *agf; /* ag. freespace structure */
+ xfs_agblock_t agflen; /* native ag. freespace length */
+ int sblock_ok; /* block passes checks */
+
+ agbp = cur->bc_private.a.agbp;
+ agf = XFS_BUF_TO_AGF(agbp);
+ agflen = INT_GET(agf->agf_length, ARCH_CONVERT);
+ sblock_ok =
+ INT_GET(block->bb_magic, ARCH_CONVERT) == xfs_magics[cur->bc_btnum] &&
+ INT_GET(block->bb_level, ARCH_CONVERT) == level &&
+ INT_GET(block->bb_numrecs, ARCH_CONVERT) <=
+ xfs_btree_maxrecs(cur, (xfs_btree_block_t *)block) &&
+ (INT_GET(block->bb_leftsib, ARCH_CONVERT) == NULLAGBLOCK ||
+ INT_GET(block->bb_leftsib, ARCH_CONVERT) < agflen) &&
+ block->bb_leftsib &&
+ (INT_GET(block->bb_rightsib, ARCH_CONVERT) == NULLAGBLOCK ||
+ INT_GET(block->bb_rightsib, ARCH_CONVERT) < agflen) &&
+ block->bb_rightsib;
+ if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
+ XFS_ERRTAG_BTREE_CHECK_SBLOCK,
+ XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
+ if (bp)
+ xfs_buftrace("SBTREE ERROR", bp);
+ XFS_ERROR_REPORT("xfs_btree_check_sblock", XFS_ERRLEVEL_LOW,
+ cur->bc_mp);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+ return 0;
+}
+
+/*
+ * Checking routine: check that (short) pointer is ok.
+ */
+int /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_sptr(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ xfs_agblock_t ptr, /* btree block disk address */
+ int level) /* btree block level */
+{
+ xfs_buf_t *agbp; /* buffer for ag. freespace struct */
+ xfs_agf_t *agf; /* ag. freespace structure */
+
+ agbp = cur->bc_private.a.agbp;
+ agf = XFS_BUF_TO_AGF(agbp);
+ XFS_WANT_CORRUPTED_RETURN(
+ level > 0 &&
+ ptr != NULLAGBLOCK && ptr != 0 &&
+ ptr < INT_GET(agf->agf_length, ARCH_CONVERT));
+ return 0;
+}
+
+/*
+ * Delete the btree cursor.
+ */
+void
+xfs_btree_del_cursor(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int error) /* del because of error */
+{
+ int i; /* btree level */
+
+ /*
+ * Clear the buffer pointers, and release the buffers.
+ * If we're doing this in the face of an error, we
+ * need to make sure to inspect all of the entries
+ * in the bc_bufs array for buffers to be unlocked.
+ * This is because some of the btree code works from
+ * level n down to 0, and if we get an error along
+ * the way we won't have initialized all the entries
+ * down to 0.
+ */
+ for (i = 0; i < cur->bc_nlevels; i++) {
+ if (cur->bc_bufs[i])
+ xfs_btree_setbuf(cur, i, NULL);
+ else if (!error)
+ break;
+ }
+ /*
+ * Can't free a bmap cursor without having dealt with the
+ * allocated indirect blocks' accounting.
+ */
+ ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
+ cur->bc_private.b.allocated == 0);
+ /*
+ * Free the cursor.
+ */
+ kmem_zone_free(xfs_btree_cur_zone, cur);
+}
+
+/*
+ * Duplicate the btree cursor.
+ * Allocate a new one, copy the record, re-get the buffers.
+ */
+int /* error */
+xfs_btree_dup_cursor(
+ xfs_btree_cur_t *cur, /* input cursor */
+ xfs_btree_cur_t **ncur) /* output cursor */
+{
+ xfs_buf_t *bp; /* btree block's buffer pointer */
+ int error; /* error return value */
+ int i; /* level number of btree block */
+ xfs_mount_t *mp; /* mount structure for filesystem */
+ xfs_btree_cur_t *new; /* new cursor value */
+ xfs_trans_t *tp; /* transaction pointer, can be NULL */
+
+ tp = cur->bc_tp;
+ mp = cur->bc_mp;
+ /*
+ * Allocate a new cursor like the old one.
+ */
+ new = xfs_btree_init_cursor(mp, tp, cur->bc_private.a.agbp,
+ cur->bc_private.a.agno, cur->bc_btnum, cur->bc_private.b.ip,
+ cur->bc_private.b.whichfork);
+ /*
+ * Copy the record currently in the cursor.
+ */
+ new->bc_rec = cur->bc_rec;
+ /*
+ * For each level current, re-get the buffer and copy the ptr value.
+ */
+ for (i = 0; i < new->bc_nlevels; i++) {
+ new->bc_ptrs[i] = cur->bc_ptrs[i];
+ new->bc_ra[i] = cur->bc_ra[i];
+ if ((bp = cur->bc_bufs[i])) {
+ if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
+ XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
+ xfs_btree_del_cursor(new, error);
+ *ncur = NULL;
+ return error;
+ }
+ new->bc_bufs[i] = bp;
+ ASSERT(bp);
+ ASSERT(!XFS_BUF_GETERROR(bp));
+ } else
+ new->bc_bufs[i] = NULL;
+ }
+ /*
+ * For bmap btrees, copy the firstblock, flist, and flags values,
+ * since init cursor doesn't get them.
+ */
+ if (new->bc_btnum == XFS_BTNUM_BMAP) {
+ new->bc_private.b.firstblock = cur->bc_private.b.firstblock;
+ new->bc_private.b.flist = cur->bc_private.b.flist;
+ new->bc_private.b.flags = cur->bc_private.b.flags;
+ }
+ *ncur = new;
+ return 0;
+}
+
+/*
+ * Change the cursor to point to the first record at the given level.
+ * Other levels are unaffected.
+ */
+int /* success=1, failure=0 */
+xfs_btree_firstrec(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int level) /* level to change */
+{
+ xfs_btree_block_t *block; /* generic btree block pointer */
+ xfs_buf_t *bp; /* buffer containing block */
+
+ /*
+ * Get the block pointer for this level.
+ */
+ block = xfs_btree_get_block(cur, level, &bp);
+ xfs_btree_check_block(cur, block, level, bp);
+ /*
+ * It's empty, there is no such record.
+ */
+ if (!block->bb_h.bb_numrecs)
+ return 0;
+ /*
+ * Set the ptr value to 1, that's the first record/key.
+ */
+ cur->bc_ptrs[level] = 1;
+ return 1;
+}
+
+/*
+ * Retrieve the block pointer from the cursor at the given level.
+ * This may be a bmap btree root or from a buffer.
+ */
+xfs_btree_block_t * /* generic btree block pointer */
+xfs_btree_get_block(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int level, /* level in btree */
+ xfs_buf_t **bpp) /* buffer containing the block */
+{
+ xfs_btree_block_t *block; /* return value */
+ xfs_buf_t *bp; /* return buffer */
+ xfs_ifork_t *ifp; /* inode fork pointer */
+ int whichfork; /* data or attr fork */
+
+ if (cur->bc_btnum == XFS_BTNUM_BMAP && level == cur->bc_nlevels - 1) {
+ whichfork = cur->bc_private.b.whichfork;
+ ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, whichfork);
+ block = (xfs_btree_block_t *)ifp->if_broot;
+ bp = NULL;
+ } else {
+ bp = cur->bc_bufs[level];
+ block = XFS_BUF_TO_BLOCK(bp);
+ }
+ ASSERT(block != NULL);
+ *bpp = bp;
+ return block;
+}
+
+/*
+ * Get a buffer for the block, return it with no data read.
+ * Long-form addressing.
+ */
+xfs_buf_t * /* buffer for fsbno */
+xfs_btree_get_bufl(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_fsblock_t fsbno, /* file system block number */
+ uint lock) /* lock flags for get_buf */
+{
+ xfs_buf_t *bp; /* buffer pointer (return value) */
+ xfs_daddr_t d; /* real disk block address */
+
+ ASSERT(fsbno != NULLFSBLOCK);
+ d = XFS_FSB_TO_DADDR(mp, fsbno);
+ bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
+ ASSERT(bp);
+ ASSERT(!XFS_BUF_GETERROR(bp));
+ return bp;
+}
+
+/*
+ * Get a buffer for the block, return it with no data read.
+ * Short-form addressing.
+ */
+xfs_buf_t * /* buffer for agno/agbno */
+xfs_btree_get_bufs(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_agnumber_t agno, /* allocation group number */
+ xfs_agblock_t agbno, /* allocation group block number */
+ uint lock) /* lock flags for get_buf */
+{
+ xfs_buf_t *bp; /* buffer pointer (return value) */
+ xfs_daddr_t d; /* real disk block address */
+
+ ASSERT(agno != NULLAGNUMBER);
+ ASSERT(agbno != NULLAGBLOCK);
+ d = XFS_AGB_TO_DADDR(mp, agno, agbno);
+ bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
+ ASSERT(bp);
+ ASSERT(!XFS_BUF_GETERROR(bp));
+ return bp;
+}
+
+/*
+ * Allocate a new btree cursor.
+ * The cursor is either for allocation (A) or bmap (B) or inodes (I).
+ */
+xfs_btree_cur_t * /* new btree cursor */
+xfs_btree_init_cursor(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_buf_t *agbp, /* (A only) buffer for agf structure */
+ /* (I only) buffer for agi structure */
+ xfs_agnumber_t agno, /* (AI only) allocation group number */
+ xfs_btnum_t btnum, /* btree identifier */
+ xfs_inode_t *ip, /* (B only) inode owning the btree */
+ int whichfork) /* (B only) data or attr fork */
+{
+ xfs_agf_t *agf; /* (A) allocation group freespace */
+ xfs_agi_t *agi; /* (I) allocation group inodespace */
+ xfs_btree_cur_t *cur; /* return value */
+ xfs_ifork_t *ifp; /* (I) inode fork pointer */
+ int nlevels=0; /* number of levels in the btree */
+
+ ASSERT(xfs_btree_cur_zone != NULL);
+ /*
+ * Allocate a new cursor.
+ */
+ cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
+ /*
+ * Deduce the number of btree levels from the arguments.
+ */
+ switch (btnum) {
+ case XFS_BTNUM_BNO:
+ case XFS_BTNUM_CNT:
+ agf = XFS_BUF_TO_AGF(agbp);
+ nlevels = INT_GET(agf->agf_levels[btnum], ARCH_CONVERT);
+ break;
+ case XFS_BTNUM_BMAP:
+ ifp = XFS_IFORK_PTR(ip, whichfork);
+ nlevels = INT_GET(ifp->if_broot->bb_level, ARCH_CONVERT) + 1;
+ break;
+ case XFS_BTNUM_INO:
+ agi = XFS_BUF_TO_AGI(agbp);
+ nlevels = INT_GET(agi->agi_level, ARCH_CONVERT);
+ break;
+ default:
+ ASSERT(0);
+ }
+ /*
+ * Fill in the common fields.
+ */
+ cur->bc_tp = tp;
+ cur->bc_mp = mp;
+ cur->bc_nlevels = nlevels;
+ cur->bc_btnum = btnum;
+ cur->bc_blocklog = mp->m_sb.sb_blocklog;
+ /*
+ * Fill in private fields.
+ */
+ switch (btnum) {
+ case XFS_BTNUM_BNO:
+ case XFS_BTNUM_CNT:
+ /*
+ * Allocation btree fields.
+ */
+ cur->bc_private.a.agbp = agbp;
+ cur->bc_private.a.agno = agno;
+ break;
+ case XFS_BTNUM_BMAP:
+ /*
+ * Bmap btree fields.
+ */
+ cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
+ cur->bc_private.b.ip = ip;
+ cur->bc_private.b.firstblock = NULLFSBLOCK;
+ cur->bc_private.b.flist = NULL;
+ cur->bc_private.b.allocated = 0;
+ cur->bc_private.b.flags = 0;
+ cur->bc_private.b.whichfork = whichfork;
+ break;
+ case XFS_BTNUM_INO:
+ /*
+ * Inode allocation btree fields.
+ */
+ cur->bc_private.i.agbp = agbp;
+ cur->bc_private.i.agno = agno;
+ break;
+ default:
+ ASSERT(0);
+ }
+ return cur;
+}
+
+/*
+ * Check for the cursor referring to the last block at the given level.
+ */
+int /* 1=is last block, 0=not last block */
+xfs_btree_islastblock(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int level) /* level to check */
+{
+ xfs_btree_block_t *block; /* generic btree block pointer */
+ xfs_buf_t *bp; /* buffer containing block */
+
+ block = xfs_btree_get_block(cur, level, &bp);
+ xfs_btree_check_block(cur, block, level, bp);
+ if (XFS_BTREE_LONG_PTRS(cur->bc_btnum))
+ return INT_GET(block->bb_u.l.bb_rightsib, ARCH_CONVERT) == NULLDFSBNO;
+ else
+ return INT_GET(block->bb_u.s.bb_rightsib, ARCH_CONVERT) == NULLAGBLOCK;
+}
+
+/*
+ * Change the cursor to point to the last record in the current block
+ * at the given level. Other levels are unaffected.
+ */
+int /* success=1, failure=0 */
+xfs_btree_lastrec(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int level) /* level to change */
+{
+ xfs_btree_block_t *block; /* generic btree block pointer */
+ xfs_buf_t *bp; /* buffer containing block */
+
+ /*
+ * Get the block pointer for this level.
+ */
+ block = xfs_btree_get_block(cur, level, &bp);
+ xfs_btree_check_block(cur, block, level, bp);
+ /*
+ * It's empty, there is no such record.
+ */
+ if (!block->bb_h.bb_numrecs)
+ return 0;
+ /*
+ * Set the ptr value to numrecs, that's the last record/key.
+ */
+ cur->bc_ptrs[level] = INT_GET(block->bb_h.bb_numrecs, ARCH_CONVERT);
+ return 1;
+}
+
+/*
+ * Compute first and last byte offsets for the fields given.
+ * Interprets the offsets table, which contains struct field offsets.
+ */
+void
+xfs_btree_offsets(
+ __int64_t fields, /* bitmask of fields */
+ const short *offsets, /* table of field offsets */
+ int nbits, /* number of bits to inspect */
+ int *first, /* output: first byte offset */
+ int *last) /* output: last byte offset */
+{
+ int i; /* current bit number */
+ __int64_t imask; /* mask for current bit number */
+
+ ASSERT(fields != 0);
+ /*
+ * Find the lowest bit, so the first byte offset.
+ */
+ for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
+ if (imask & fields) {
+ *first = offsets[i];
+ break;
+ }
+ }
+ /*
+ * Find the highest bit, so the last byte offset.
+ */
+ for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
+ if (imask & fields) {
+ *last = offsets[i + 1] - 1;
+ break;
+ }
+ }
+}
+
+/*
+ * Get a buffer for the block, return it read in.
+ * Long-form addressing.
+ */
+int /* error */
+xfs_btree_read_bufl(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_fsblock_t fsbno, /* file system block number */
+ uint lock, /* lock flags for read_buf */
+ xfs_buf_t **bpp, /* buffer for fsbno */
+ int refval) /* ref count value for buffer */
+{
+ xfs_buf_t *bp; /* return value */
+ xfs_daddr_t d; /* real disk block address */
+ int error;
+
+ ASSERT(fsbno != NULLFSBLOCK);
+ d = XFS_FSB_TO_DADDR(mp, fsbno);
+ if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
+ mp->m_bsize, lock, &bp))) {
+ return error;
+ }
+ ASSERT(!bp || !XFS_BUF_GETERROR(bp));
+ if (bp != NULL) {
+ XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
+ }
+ *bpp = bp;
+ return 0;
+}
+
+/*
+ * Get a buffer for the block, return it read in.
+ * Short-form addressing.
+ */
+int /* error */
+xfs_btree_read_bufs(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_agnumber_t agno, /* allocation group number */
+ xfs_agblock_t agbno, /* allocation group block number */
+ uint lock, /* lock flags for read_buf */
+ xfs_buf_t **bpp, /* buffer for agno/agbno */
+ int refval) /* ref count value for buffer */
+{
+ xfs_buf_t *bp; /* return value */
+ xfs_daddr_t d; /* real disk block address */
+ int error;
+
+ ASSERT(agno != NULLAGNUMBER);
+ ASSERT(agbno != NULLAGBLOCK);
+ d = XFS_AGB_TO_DADDR(mp, agno, agbno);
+ if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
+ mp->m_bsize, lock, &bp))) {
+ return error;
+ }
+ ASSERT(!bp || !XFS_BUF_GETERROR(bp));
+ if (bp != NULL) {
+ switch (refval) {
+ case XFS_ALLOC_BTREE_REF:
+ XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
+ break;
+ case XFS_INO_BTREE_REF:
+ XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, refval);
+ break;
+ }
+ }
+ *bpp = bp;
+ return 0;
+}
+
+/*
+ * Read-ahead the block, don't wait for it, don't return a buffer.
+ * Long-form addressing.
+ */
+/* ARGSUSED */
+void
+xfs_btree_reada_bufl(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_fsblock_t fsbno, /* file system block number */
+ xfs_extlen_t count) /* count of filesystem blocks */
+{
+ xfs_daddr_t d;
+
+ ASSERT(fsbno != NULLFSBLOCK);
+ d = XFS_FSB_TO_DADDR(mp, fsbno);
+ xfs_baread(mp->m_ddev_targp, d, mp->m_bsize * count);
+}
+
+/*
+ * Read-ahead the block, don't wait for it, don't return a buffer.
+ * Short-form addressing.
+ */
+/* ARGSUSED */
+void
+xfs_btree_reada_bufs(
+ xfs_mount_t *mp, /* file system mount point */
+ xfs_agnumber_t agno, /* allocation group number */
+ xfs_agblock_t agbno, /* allocation group block number */
+ xfs_extlen_t count) /* count of filesystem blocks */
+{
+ xfs_daddr_t d;
+
+ ASSERT(agno != NULLAGNUMBER);
+ ASSERT(agbno != NULLAGBLOCK);
+ d = XFS_AGB_TO_DADDR(mp, agno, agbno);
+ xfs_baread(mp->m_ddev_targp, d, mp->m_bsize * count);
+}
+
+/*
+ * Read-ahead btree blocks, at the given level.
+ * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
+ */
+int
+xfs_btree_readahead_core(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int lev, /* level in btree */
+ int lr) /* left/right bits */
+{
+ xfs_alloc_block_t *a;
+ xfs_bmbt_block_t *b;
+ xfs_inobt_block_t *i;
+ int rval = 0;
+
+ ASSERT(cur->bc_bufs[lev] != NULL);
+ cur->bc_ra[lev] |= lr;
+ switch (cur->bc_btnum) {
+ case XFS_BTNUM_BNO:
+ case XFS_BTNUM_CNT:
+ a = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[lev]);
+ if ((lr & XFS_BTCUR_LEFTRA) && INT_GET(a->bb_leftsib, ARCH_CONVERT) != NULLAGBLOCK) {
+ xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
+ INT_GET(a->bb_leftsib, ARCH_CONVERT), 1);
+ rval++;
+ }
+ if ((lr & XFS_BTCUR_RIGHTRA) && INT_GET(a->bb_rightsib, ARCH_CONVERT) != NULLAGBLOCK) {
+ xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
+ INT_GET(a->bb_rightsib, ARCH_CONVERT), 1);
+ rval++;
+ }
+ break;
+ case XFS_BTNUM_BMAP:
+ b = XFS_BUF_TO_BMBT_BLOCK(cur->bc_bufs[lev]);
+ if ((lr & XFS_BTCUR_LEFTRA) && INT_GET(b->bb_leftsib, ARCH_CONVERT) != NULLDFSBNO) {
+ xfs_btree_reada_bufl(cur->bc_mp, INT_GET(b->bb_leftsib, ARCH_CONVERT), 1);
+ rval++;
+ }
+ if ((lr & XFS_BTCUR_RIGHTRA) && INT_GET(b->bb_rightsib, ARCH_CONVERT) != NULLDFSBNO) {
+ xfs_btree_reada_bufl(cur->bc_mp, INT_GET(b->bb_rightsib, ARCH_CONVERT), 1);
+ rval++;
+ }
+ break;
+ case XFS_BTNUM_INO:
+ i = XFS_BUF_TO_INOBT_BLOCK(cur->bc_bufs[lev]);
+ if ((lr & XFS_BTCUR_LEFTRA) && INT_GET(i->bb_leftsib, ARCH_CONVERT) != NULLAGBLOCK) {
+ xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.i.agno,
+ INT_GET(i->bb_leftsib, ARCH_CONVERT), 1);
+ rval++;
+ }
+ if ((lr & XFS_BTCUR_RIGHTRA) && INT_GET(i->bb_rightsib, ARCH_CONVERT) != NULLAGBLOCK) {
+ xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.i.agno,
+ INT_GET(i->bb_rightsib, ARCH_CONVERT), 1);
+ rval++;
+ }
+ break;
+ default:
+ ASSERT(0);
+ }
+ return rval;
+}
+
+/*
+ * Set the buffer for level "lev" in the cursor to bp, releasing
+ * any previous buffer.
+ */
+void
+xfs_btree_setbuf(
+ xfs_btree_cur_t *cur, /* btree cursor */
+ int lev, /* level in btree */
+ xfs_buf_t *bp) /* new buffer to set */
+{
+ xfs_btree_block_t *b; /* btree block */
+ xfs_buf_t *obp; /* old buffer pointer */
+
+ obp = cur->bc_bufs[lev];
+ if (obp)
+ xfs_trans_brelse(cur->bc_tp, obp);
+ cur->bc_bufs[lev] = bp;
+ cur->bc_ra[lev] = 0;
+ if (!bp)
+ return;
+ b = XFS_BUF_TO_BLOCK(bp);
+ if (XFS_BTREE_LONG_PTRS(cur->bc_btnum)) {
+ if (INT_GET(b->bb_u.l.bb_leftsib, ARCH_CONVERT) == NULLDFSBNO)
+ cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
+ if (INT_GET(b->bb_u.l.bb_rightsib, ARCH_CONVERT) == NULLDFSBNO)
+ cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
+ } else {
+ if (INT_GET(b->bb_u.s.bb_leftsib, ARCH_CONVERT) == NULLAGBLOCK)
+ cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
+ if (INT_GET(b->bb_u.s.bb_rightsib, ARCH_CONVERT) == NULLAGBLOCK)
+ cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
+ }
+}
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