Add new helpers in xfs_btree.c to find the record, key and block pointer entries inside a btree block. To implement this genericly the ->get_maxrecs methods and two new xfs_btree_ops entries for the key and record sizes are used. Also add a big comment describing how the addressing inside a btree block works. Note that these helpers are unused until users are introduced in the next patches and this patch will thus cause some harmless compiler warnings. SGI-PV: 985583 SGI-Modid: xfs-linux-melb:xfs-kern:32189a Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Bill O'Donnell <billodo@sgi.com> Signed-off-by: David Chinner <david@fromorbit.com>
952 lines
24 KiB
C
952 lines
24 KiB
C
/*
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* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms 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,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_types.h"
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#include "xfs_bit.h"
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#include "xfs_log.h"
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#include "xfs_inum.h"
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#include "xfs_trans.h"
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#include "xfs_sb.h"
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#include "xfs_ag.h"
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#include "xfs_dir2.h"
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#include "xfs_dmapi.h"
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#include "xfs_mount.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_alloc_btree.h"
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#include "xfs_ialloc_btree.h"
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#include "xfs_dir2_sf.h"
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#include "xfs_attr_sf.h"
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#include "xfs_dinode.h"
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#include "xfs_inode.h"
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#include "xfs_btree.h"
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#include "xfs_ialloc.h"
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#include "xfs_error.h"
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/*
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* Cursor allocation zone.
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*/
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kmem_zone_t *xfs_btree_cur_zone;
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/*
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* Btree magic numbers.
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*/
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const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
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XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
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};
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/*
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* External routines.
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*/
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#ifdef DEBUG
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/*
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* Debug routine: check that keys are in the right order.
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*/
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void
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xfs_btree_check_key(
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xfs_btnum_t btnum, /* btree identifier */
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void *ak1, /* pointer to left (lower) key */
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void *ak2) /* pointer to right (higher) key */
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{
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switch (btnum) {
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case XFS_BTNUM_BNO: {
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xfs_alloc_key_t *k1;
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xfs_alloc_key_t *k2;
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k1 = ak1;
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k2 = ak2;
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ASSERT(be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock));
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break;
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}
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case XFS_BTNUM_CNT: {
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xfs_alloc_key_t *k1;
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xfs_alloc_key_t *k2;
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k1 = ak1;
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k2 = ak2;
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ASSERT(be32_to_cpu(k1->ar_blockcount) < be32_to_cpu(k2->ar_blockcount) ||
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(k1->ar_blockcount == k2->ar_blockcount &&
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be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock)));
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break;
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}
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case XFS_BTNUM_BMAP: {
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xfs_bmbt_key_t *k1;
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xfs_bmbt_key_t *k2;
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k1 = ak1;
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k2 = ak2;
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ASSERT(be64_to_cpu(k1->br_startoff) < be64_to_cpu(k2->br_startoff));
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break;
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}
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case XFS_BTNUM_INO: {
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xfs_inobt_key_t *k1;
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xfs_inobt_key_t *k2;
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k1 = ak1;
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k2 = ak2;
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ASSERT(be32_to_cpu(k1->ir_startino) < be32_to_cpu(k2->ir_startino));
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break;
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}
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default:
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ASSERT(0);
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}
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}
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/*
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* Debug routine: check that records are in the right order.
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*/
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void
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xfs_btree_check_rec(
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xfs_btnum_t btnum, /* btree identifier */
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void *ar1, /* pointer to left (lower) record */
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void *ar2) /* pointer to right (higher) record */
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{
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switch (btnum) {
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case XFS_BTNUM_BNO: {
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xfs_alloc_rec_t *r1;
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xfs_alloc_rec_t *r2;
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r1 = ar1;
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r2 = ar2;
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ASSERT(be32_to_cpu(r1->ar_startblock) +
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be32_to_cpu(r1->ar_blockcount) <=
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be32_to_cpu(r2->ar_startblock));
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break;
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}
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case XFS_BTNUM_CNT: {
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xfs_alloc_rec_t *r1;
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xfs_alloc_rec_t *r2;
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r1 = ar1;
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r2 = ar2;
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ASSERT(be32_to_cpu(r1->ar_blockcount) < be32_to_cpu(r2->ar_blockcount) ||
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(r1->ar_blockcount == r2->ar_blockcount &&
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be32_to_cpu(r1->ar_startblock) < be32_to_cpu(r2->ar_startblock)));
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break;
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}
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case XFS_BTNUM_BMAP: {
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xfs_bmbt_rec_t *r1;
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xfs_bmbt_rec_t *r2;
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r1 = ar1;
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r2 = ar2;
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ASSERT(xfs_bmbt_disk_get_startoff(r1) +
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xfs_bmbt_disk_get_blockcount(r1) <=
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xfs_bmbt_disk_get_startoff(r2));
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break;
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}
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case XFS_BTNUM_INO: {
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xfs_inobt_rec_t *r1;
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xfs_inobt_rec_t *r2;
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r1 = ar1;
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r2 = ar2;
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ASSERT(be32_to_cpu(r1->ir_startino) + XFS_INODES_PER_CHUNK <=
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be32_to_cpu(r2->ir_startino));
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break;
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}
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default:
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ASSERT(0);
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}
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}
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#endif /* DEBUG */
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int /* error (0 or EFSCORRUPTED) */
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xfs_btree_check_lblock(
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struct xfs_btree_cur *cur, /* btree cursor */
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struct xfs_btree_lblock *block, /* btree long form block pointer */
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int level, /* level of the btree block */
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struct xfs_buf *bp) /* buffer for block, if any */
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{
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int lblock_ok; /* block passes checks */
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struct xfs_mount *mp; /* file system mount point */
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mp = cur->bc_mp;
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lblock_ok =
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be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
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be16_to_cpu(block->bb_level) == level &&
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be16_to_cpu(block->bb_numrecs) <=
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cur->bc_ops->get_maxrecs(cur, level) &&
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block->bb_leftsib &&
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(be64_to_cpu(block->bb_leftsib) == NULLDFSBNO ||
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XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_leftsib))) &&
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block->bb_rightsib &&
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(be64_to_cpu(block->bb_rightsib) == NULLDFSBNO ||
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XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_rightsib)));
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if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
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XFS_ERRTAG_BTREE_CHECK_LBLOCK,
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XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
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if (bp)
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xfs_buftrace("LBTREE ERROR", bp);
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XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
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mp);
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return XFS_ERROR(EFSCORRUPTED);
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}
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return 0;
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}
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int /* error (0 or EFSCORRUPTED) */
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xfs_btree_check_sblock(
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struct xfs_btree_cur *cur, /* btree cursor */
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struct xfs_btree_sblock *block, /* btree short form block pointer */
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int level, /* level of the btree block */
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struct xfs_buf *bp) /* buffer containing block */
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{
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struct xfs_buf *agbp; /* buffer for ag. freespace struct */
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struct xfs_agf *agf; /* ag. freespace structure */
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xfs_agblock_t agflen; /* native ag. freespace length */
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int sblock_ok; /* block passes checks */
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agbp = cur->bc_private.a.agbp;
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agf = XFS_BUF_TO_AGF(agbp);
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agflen = be32_to_cpu(agf->agf_length);
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sblock_ok =
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be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
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be16_to_cpu(block->bb_level) == level &&
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be16_to_cpu(block->bb_numrecs) <=
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cur->bc_ops->get_maxrecs(cur, level) &&
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(be32_to_cpu(block->bb_leftsib) == NULLAGBLOCK ||
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be32_to_cpu(block->bb_leftsib) < agflen) &&
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block->bb_leftsib &&
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(be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK ||
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be32_to_cpu(block->bb_rightsib) < agflen) &&
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block->bb_rightsib;
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if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
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XFS_ERRTAG_BTREE_CHECK_SBLOCK,
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XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
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if (bp)
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xfs_buftrace("SBTREE ERROR", bp);
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XFS_ERROR_REPORT("xfs_btree_check_sblock", XFS_ERRLEVEL_LOW,
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cur->bc_mp);
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return XFS_ERROR(EFSCORRUPTED);
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}
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return 0;
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}
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/*
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* Debug routine: check that block header is ok.
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*/
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int
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xfs_btree_check_block(
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struct xfs_btree_cur *cur, /* btree cursor */
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struct xfs_btree_block *block, /* generic btree block pointer */
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int level, /* level of the btree block */
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struct xfs_buf *bp) /* buffer containing block, if any */
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{
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if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
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return xfs_btree_check_lblock(cur,
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(struct xfs_btree_lblock *)block, level, bp);
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} else {
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return xfs_btree_check_sblock(cur,
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(struct xfs_btree_sblock *)block, level, bp);
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}
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}
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/*
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* Check that (long) pointer is ok.
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*/
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int /* error (0 or EFSCORRUPTED) */
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xfs_btree_check_lptr(
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struct xfs_btree_cur *cur, /* btree cursor */
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xfs_dfsbno_t bno, /* btree block disk address */
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int level) /* btree block level */
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{
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XFS_WANT_CORRUPTED_RETURN(
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level > 0 &&
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bno != NULLDFSBNO &&
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XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
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return 0;
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}
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/*
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* Check that (short) pointer is ok.
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*/
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int /* error (0 or EFSCORRUPTED) */
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xfs_btree_check_sptr(
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struct xfs_btree_cur *cur, /* btree cursor */
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xfs_agblock_t bno, /* btree block disk address */
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int level) /* btree block level */
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{
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xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
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XFS_WANT_CORRUPTED_RETURN(
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level > 0 &&
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bno != NULLAGBLOCK &&
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bno != 0 &&
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bno < agblocks);
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return 0;
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}
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/*
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* Check that block ptr is ok.
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*/
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int /* error (0 or EFSCORRUPTED) */
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xfs_btree_check_ptr(
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struct xfs_btree_cur *cur, /* btree cursor */
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union xfs_btree_ptr *ptr, /* btree block disk address */
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int index, /* offset from ptr to check */
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int level) /* btree block level */
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{
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if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
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return xfs_btree_check_lptr(cur,
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be64_to_cpu((&ptr->l)[index]), level);
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} else {
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return xfs_btree_check_sptr(cur,
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be32_to_cpu((&ptr->s)[index]), level);
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}
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}
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/*
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* Delete the btree cursor.
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*/
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void
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xfs_btree_del_cursor(
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xfs_btree_cur_t *cur, /* btree cursor */
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int error) /* del because of error */
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{
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int i; /* btree level */
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/*
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* Clear the buffer pointers, and release the buffers.
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* If we're doing this in the face of an error, we
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* need to make sure to inspect all of the entries
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* in the bc_bufs array for buffers to be unlocked.
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* This is because some of the btree code works from
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* level n down to 0, and if we get an error along
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* the way we won't have initialized all the entries
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* down to 0.
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*/
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for (i = 0; i < cur->bc_nlevels; i++) {
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if (cur->bc_bufs[i])
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xfs_btree_setbuf(cur, i, NULL);
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else if (!error)
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break;
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}
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/*
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* Can't free a bmap cursor without having dealt with the
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* allocated indirect blocks' accounting.
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*/
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ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
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cur->bc_private.b.allocated == 0);
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/*
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* Free the cursor.
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*/
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kmem_zone_free(xfs_btree_cur_zone, cur);
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}
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/*
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* Duplicate the btree cursor.
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* Allocate a new one, copy the record, re-get the buffers.
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*/
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int /* error */
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xfs_btree_dup_cursor(
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xfs_btree_cur_t *cur, /* input cursor */
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xfs_btree_cur_t **ncur) /* output cursor */
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{
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xfs_buf_t *bp; /* btree block's buffer pointer */
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int error; /* error return value */
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int i; /* level number of btree block */
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xfs_mount_t *mp; /* mount structure for filesystem */
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xfs_btree_cur_t *new; /* new cursor value */
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xfs_trans_t *tp; /* transaction pointer, can be NULL */
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tp = cur->bc_tp;
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mp = cur->bc_mp;
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/*
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* Allocate a new cursor like the old one.
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*/
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new = cur->bc_ops->dup_cursor(cur);
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/*
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* Copy the record currently in the cursor.
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*/
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new->bc_rec = cur->bc_rec;
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/*
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* For each level current, re-get the buffer and copy the ptr value.
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*/
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for (i = 0; i < new->bc_nlevels; i++) {
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new->bc_ptrs[i] = cur->bc_ptrs[i];
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new->bc_ra[i] = cur->bc_ra[i];
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if ((bp = cur->bc_bufs[i])) {
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if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
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XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
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xfs_btree_del_cursor(new, error);
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*ncur = NULL;
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return error;
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}
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new->bc_bufs[i] = bp;
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ASSERT(bp);
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ASSERT(!XFS_BUF_GETERROR(bp));
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} else
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new->bc_bufs[i] = NULL;
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}
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*ncur = new;
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return 0;
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}
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/*
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* XFS btree block layout and addressing:
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*
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* There are two types of blocks in the btree: leaf and non-leaf blocks.
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*
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* The leaf record start with a header then followed by records containing
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* the values. A non-leaf block also starts with the same header, and
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* then first contains lookup keys followed by an equal number of pointers
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* to the btree blocks at the previous level.
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*
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* +--------+-------+-------+-------+-------+-------+-------+
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* Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
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* +--------+-------+-------+-------+-------+-------+-------+
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*
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* +--------+-------+-------+-------+-------+-------+-------+
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* Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
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* +--------+-------+-------+-------+-------+-------+-------+
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*
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* The header is called struct xfs_btree_block for reasons better left unknown
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* and comes in different versions for short (32bit) and long (64bit) block
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* pointers. The record and key structures are defined by the btree instances
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* and opaque to the btree core. The block pointers are simple disk endian
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* integers, available in a short (32bit) and long (64bit) variant.
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*
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* The helpers below calculate the offset of a given record, key or pointer
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* into a btree block (xfs_btree_*_offset) or return a pointer to the given
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* record, key or pointer (xfs_btree_*_addr). Note that all addressing
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* inside the btree block is done using indices starting at one, not zero!
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*/
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/*
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* Return size of the btree block header for this btree instance.
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*/
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static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
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{
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return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
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sizeof(struct xfs_btree_lblock) :
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sizeof(struct xfs_btree_sblock);
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}
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/*
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* Return size of btree block pointers for this btree instance.
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*/
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static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
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{
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return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
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sizeof(__be64) : sizeof(__be32);
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}
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/*
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* Calculate offset of the n-th record in a btree block.
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*/
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STATIC size_t
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xfs_btree_rec_offset(
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struct xfs_btree_cur *cur,
|
|
int n)
|
|
{
|
|
return xfs_btree_block_len(cur) +
|
|
(n - 1) * cur->bc_ops->rec_len;
|
|
}
|
|
|
|
/*
|
|
* Calculate offset of the n-th key in a btree block.
|
|
*/
|
|
STATIC size_t
|
|
xfs_btree_key_offset(
|
|
struct xfs_btree_cur *cur,
|
|
int n)
|
|
{
|
|
return xfs_btree_block_len(cur) +
|
|
(n - 1) * cur->bc_ops->key_len;
|
|
}
|
|
|
|
/*
|
|
* Calculate offset of the n-th block pointer in a btree block.
|
|
*/
|
|
STATIC size_t
|
|
xfs_btree_ptr_offset(
|
|
struct xfs_btree_cur *cur,
|
|
int n,
|
|
int level)
|
|
{
|
|
return xfs_btree_block_len(cur) +
|
|
cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
|
|
(n - 1) * xfs_btree_ptr_len(cur);
|
|
}
|
|
|
|
/*
|
|
* Return a pointer to the n-th record in the btree block.
|
|
*/
|
|
STATIC union xfs_btree_rec *
|
|
xfs_btree_rec_addr(
|
|
struct xfs_btree_cur *cur,
|
|
int n,
|
|
struct xfs_btree_block *block)
|
|
{
|
|
return (union xfs_btree_rec *)
|
|
((char *)block + xfs_btree_rec_offset(cur, n));
|
|
}
|
|
|
|
/*
|
|
* Return a pointer to the n-th key in the btree block.
|
|
*/
|
|
STATIC union xfs_btree_key *
|
|
xfs_btree_key_addr(
|
|
struct xfs_btree_cur *cur,
|
|
int n,
|
|
struct xfs_btree_block *block)
|
|
{
|
|
return (union xfs_btree_key *)
|
|
((char *)block + xfs_btree_key_offset(cur, n));
|
|
}
|
|
|
|
/*
|
|
* Return a pointer to the n-th block pointer in the btree block.
|
|
*/
|
|
STATIC union xfs_btree_ptr *
|
|
xfs_btree_ptr_addr(
|
|
struct xfs_btree_cur *cur,
|
|
int n,
|
|
struct xfs_btree_block *block)
|
|
{
|
|
int level = xfs_btree_get_level(block);
|
|
|
|
ASSERT(block->bb_level != 0);
|
|
|
|
return (union xfs_btree_ptr *)
|
|
((char *)block + xfs_btree_ptr_offset(cur, n, level));
|
|
}
|
|
|
|
/*
|
|
* Get a the root block which is stored in the inode.
|
|
*
|
|
* For now this btree implementation assumes the btree root is always
|
|
* stored in the if_broot field of an inode fork.
|
|
*/
|
|
STATIC struct xfs_btree_block *
|
|
xfs_btree_get_iroot(
|
|
struct xfs_btree_cur *cur)
|
|
{
|
|
struct xfs_ifork *ifp;
|
|
|
|
ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
|
|
return (struct xfs_btree_block *)ifp->if_broot;
|
|
}
|
|
|
|
/*
|
|
* Retrieve the block pointer from the cursor at the given level.
|
|
* This may be an inode btree root or from a buffer.
|
|
*/
|
|
STATIC struct xfs_btree_block * /* generic btree block pointer */
|
|
xfs_btree_get_block(
|
|
struct xfs_btree_cur *cur, /* btree cursor */
|
|
int level, /* level in btree */
|
|
struct xfs_buf **bpp) /* buffer containing the block */
|
|
{
|
|
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
|
|
(level == cur->bc_nlevels - 1)) {
|
|
*bpp = NULL;
|
|
return xfs_btree_get_iroot(cur);
|
|
}
|
|
|
|
*bpp = cur->bc_bufs[level];
|
|
return XFS_BUF_TO_BLOCK(*bpp);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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 (cur->bc_flags & XFS_BTREE_LONG_PTRS)
|
|
return be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO;
|
|
else
|
|
return be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK;
|
|
}
|
|
|
|
/*
|
|
* 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_numrecs)
|
|
return 0;
|
|
/*
|
|
* Set the ptr value to 1, that's the first record/key.
|
|
*/
|
|
cur->bc_ptrs[level] = 1;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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_numrecs)
|
|
return 0;
|
|
/*
|
|
* Set the ptr value to numrecs, that's the last record/key.
|
|
*/
|
|
cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
|
|
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);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_btree_readahead_lblock(
|
|
struct xfs_btree_cur *cur,
|
|
int lr,
|
|
struct xfs_btree_block *block)
|
|
{
|
|
int rval = 0;
|
|
xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
|
|
xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
|
|
|
|
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
|
|
xfs_btree_reada_bufl(cur->bc_mp, left, 1);
|
|
rval++;
|
|
}
|
|
|
|
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
|
|
xfs_btree_reada_bufl(cur->bc_mp, right, 1);
|
|
rval++;
|
|
}
|
|
|
|
return rval;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_btree_readahead_sblock(
|
|
struct xfs_btree_cur *cur,
|
|
int lr,
|
|
struct xfs_btree_block *block)
|
|
{
|
|
int rval = 0;
|
|
xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
|
|
xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
|
|
|
|
|
|
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
|
|
xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
|
|
left, 1);
|
|
rval++;
|
|
}
|
|
|
|
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
|
|
xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
|
|
right, 1);
|
|
rval++;
|
|
}
|
|
|
|
return rval;
|
|
}
|
|
|
|
/*
|
|
* Read-ahead btree blocks, at the given level.
|
|
* Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
|
|
*/
|
|
int
|
|
xfs_btree_readahead(
|
|
struct xfs_btree_cur *cur, /* btree cursor */
|
|
int lev, /* level in btree */
|
|
int lr) /* left/right bits */
|
|
{
|
|
struct xfs_btree_block *block;
|
|
|
|
/*
|
|
* No readahead needed if we are at the root level and the
|
|
* btree root is stored in the inode.
|
|
*/
|
|
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
|
|
(lev == cur->bc_nlevels - 1))
|
|
return 0;
|
|
|
|
if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
|
|
return 0;
|
|
|
|
cur->bc_ra[lev] |= lr;
|
|
block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
|
|
|
|
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
|
|
return xfs_btree_readahead_lblock(cur, lr, block);
|
|
return xfs_btree_readahead_sblock(cur, lr, block);
|
|
}
|
|
|
|
/*
|
|
* 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 (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
|
|
if (be64_to_cpu(b->bb_u.l.bb_leftsib) == NULLDFSBNO)
|
|
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
|
|
if (be64_to_cpu(b->bb_u.l.bb_rightsib) == NULLDFSBNO)
|
|
cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
|
|
} else {
|
|
if (be32_to_cpu(b->bb_u.s.bb_leftsib) == NULLAGBLOCK)
|
|
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
|
|
if (be32_to_cpu(b->bb_u.s.bb_rightsib) == NULLAGBLOCK)
|
|
cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
|
|
}
|
|
}
|