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In the course of some operations, we look up the perag from the mount multiple times to get or change perag information. These are often very short pieces of code, so while the lookup cost is generally low, the cost of the lookup is far higher than the cost of the operation we are doing on the perag. Since we changed buffers to hold references to the perag they are cached in, many modification contexts already hold active references to the perag that are held across these operations. This is especially true for any operation that is serialised by an allocation group header buffer. In these cases, we can just use the buffer's reference to the perag to avoid needing to do lookups to access the perag. This means that many operations don't need to do perag lookups at all to access the perag because they've already looked up objects that own persistent references and hence can use that reference instead. Cc: Dave Chinner <dchinner@redhat.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Signed-off-by: Gao Xiang <hsiangkao@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
638 lines
16 KiB
C
638 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2014 Red Hat, Inc.
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* All Rights Reserved.
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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_shared.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
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#include "xfs_trans_resv.h"
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#include "xfs_sb.h"
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#include "xfs_mount.h"
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#include "xfs_trans.h"
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#include "xfs_alloc.h"
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#include "xfs_btree.h"
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#include "xfs_btree_staging.h"
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#include "xfs_rmap.h"
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#include "xfs_rmap_btree.h"
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#include "xfs_trace.h"
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#include "xfs_error.h"
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#include "xfs_extent_busy.h"
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#include "xfs_ag_resv.h"
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/*
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* Reverse map btree.
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*
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* This is a per-ag tree used to track the owner(s) of a given extent. With
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* reflink it is possible for there to be multiple owners, which is a departure
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* from classic XFS. Owner records for data extents are inserted when the
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* extent is mapped and removed when an extent is unmapped. Owner records for
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* all other block types (i.e. metadata) are inserted when an extent is
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* allocated and removed when an extent is freed. There can only be one owner
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* of a metadata extent, usually an inode or some other metadata structure like
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* an AG btree.
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*
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* The rmap btree is part of the free space management, so blocks for the tree
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* are sourced from the agfl. Hence we need transaction reservation support for
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* this tree so that the freelist is always large enough. This also impacts on
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* the minimum space we need to leave free in the AG.
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*
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* The tree is ordered by [ag block, owner, offset]. This is a large key size,
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* but it is the only way to enforce unique keys when a block can be owned by
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* multiple files at any offset. There's no need to order/search by extent
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* size for online updating/management of the tree. It is intended that most
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* reverse lookups will be to find the owner(s) of a particular block, or to
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* try to recover tree and file data from corrupt primary metadata.
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*/
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static struct xfs_btree_cur *
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xfs_rmapbt_dup_cursor(
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struct xfs_btree_cur *cur)
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{
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return xfs_rmapbt_init_cursor(cur->bc_mp, cur->bc_tp,
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cur->bc_ag.agbp, cur->bc_ag.agno);
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}
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STATIC void
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xfs_rmapbt_set_root(
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struct xfs_btree_cur *cur,
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union xfs_btree_ptr *ptr,
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int inc)
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{
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struct xfs_buf *agbp = cur->bc_ag.agbp;
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struct xfs_agf *agf = agbp->b_addr;
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int btnum = cur->bc_btnum;
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struct xfs_perag *pag = agbp->b_pag;
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ASSERT(ptr->s != 0);
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agf->agf_roots[btnum] = ptr->s;
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be32_add_cpu(&agf->agf_levels[btnum], inc);
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pag->pagf_levels[btnum] += inc;
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xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
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}
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STATIC int
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xfs_rmapbt_alloc_block(
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struct xfs_btree_cur *cur,
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union xfs_btree_ptr *start,
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union xfs_btree_ptr *new,
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int *stat)
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{
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struct xfs_buf *agbp = cur->bc_ag.agbp;
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struct xfs_agf *agf = agbp->b_addr;
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int error;
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xfs_agblock_t bno;
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/* Allocate the new block from the freelist. If we can't, give up. */
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error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_ag.agbp,
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&bno, 1);
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if (error)
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return error;
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trace_xfs_rmapbt_alloc_block(cur->bc_mp, cur->bc_ag.agno,
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bno, 1);
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if (bno == NULLAGBLOCK) {
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*stat = 0;
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return 0;
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}
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xfs_extent_busy_reuse(cur->bc_mp, cur->bc_ag.agno, bno, 1,
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false);
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xfs_trans_agbtree_delta(cur->bc_tp, 1);
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new->s = cpu_to_be32(bno);
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be32_add_cpu(&agf->agf_rmap_blocks, 1);
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xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
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xfs_ag_resv_rmapbt_alloc(cur->bc_mp, cur->bc_ag.agno);
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*stat = 1;
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return 0;
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}
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STATIC int
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xfs_rmapbt_free_block(
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struct xfs_btree_cur *cur,
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struct xfs_buf *bp)
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{
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struct xfs_buf *agbp = cur->bc_ag.agbp;
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struct xfs_agf *agf = agbp->b_addr;
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struct xfs_perag *pag;
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xfs_agblock_t bno;
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int error;
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bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
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trace_xfs_rmapbt_free_block(cur->bc_mp, cur->bc_ag.agno,
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bno, 1);
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be32_add_cpu(&agf->agf_rmap_blocks, -1);
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xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
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error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
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if (error)
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return error;
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xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
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XFS_EXTENT_BUSY_SKIP_DISCARD);
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xfs_trans_agbtree_delta(cur->bc_tp, -1);
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pag = cur->bc_ag.agbp->b_pag;
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xfs_ag_resv_free_extent(pag, XFS_AG_RESV_RMAPBT, NULL, 1);
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return 0;
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}
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STATIC int
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xfs_rmapbt_get_minrecs(
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struct xfs_btree_cur *cur,
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int level)
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{
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return cur->bc_mp->m_rmap_mnr[level != 0];
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}
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STATIC int
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xfs_rmapbt_get_maxrecs(
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struct xfs_btree_cur *cur,
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int level)
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{
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return cur->bc_mp->m_rmap_mxr[level != 0];
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}
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STATIC void
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xfs_rmapbt_init_key_from_rec(
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union xfs_btree_key *key,
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union xfs_btree_rec *rec)
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{
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key->rmap.rm_startblock = rec->rmap.rm_startblock;
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key->rmap.rm_owner = rec->rmap.rm_owner;
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key->rmap.rm_offset = rec->rmap.rm_offset;
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}
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/*
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* The high key for a reverse mapping record can be computed by shifting
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* the startblock and offset to the highest value that would still map
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* to that record. In practice this means that we add blockcount-1 to
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* the startblock for all records, and if the record is for a data/attr
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* fork mapping, we add blockcount-1 to the offset too.
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*/
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STATIC void
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xfs_rmapbt_init_high_key_from_rec(
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union xfs_btree_key *key,
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union xfs_btree_rec *rec)
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{
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uint64_t off;
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int adj;
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adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1;
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key->rmap.rm_startblock = rec->rmap.rm_startblock;
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be32_add_cpu(&key->rmap.rm_startblock, adj);
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key->rmap.rm_owner = rec->rmap.rm_owner;
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key->rmap.rm_offset = rec->rmap.rm_offset;
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if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) ||
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XFS_RMAP_IS_BMBT_BLOCK(be64_to_cpu(rec->rmap.rm_offset)))
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return;
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off = be64_to_cpu(key->rmap.rm_offset);
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off = (XFS_RMAP_OFF(off) + adj) | (off & ~XFS_RMAP_OFF_MASK);
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key->rmap.rm_offset = cpu_to_be64(off);
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}
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STATIC void
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xfs_rmapbt_init_rec_from_cur(
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struct xfs_btree_cur *cur,
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union xfs_btree_rec *rec)
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{
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rec->rmap.rm_startblock = cpu_to_be32(cur->bc_rec.r.rm_startblock);
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rec->rmap.rm_blockcount = cpu_to_be32(cur->bc_rec.r.rm_blockcount);
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rec->rmap.rm_owner = cpu_to_be64(cur->bc_rec.r.rm_owner);
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rec->rmap.rm_offset = cpu_to_be64(
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xfs_rmap_irec_offset_pack(&cur->bc_rec.r));
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}
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STATIC void
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xfs_rmapbt_init_ptr_from_cur(
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struct xfs_btree_cur *cur,
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union xfs_btree_ptr *ptr)
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{
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struct xfs_agf *agf = cur->bc_ag.agbp->b_addr;
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ASSERT(cur->bc_ag.agno == be32_to_cpu(agf->agf_seqno));
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ptr->s = agf->agf_roots[cur->bc_btnum];
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}
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STATIC int64_t
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xfs_rmapbt_key_diff(
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struct xfs_btree_cur *cur,
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union xfs_btree_key *key)
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{
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struct xfs_rmap_irec *rec = &cur->bc_rec.r;
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struct xfs_rmap_key *kp = &key->rmap;
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__u64 x, y;
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int64_t d;
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d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
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if (d)
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return d;
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x = be64_to_cpu(kp->rm_owner);
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y = rec->rm_owner;
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if (x > y)
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return 1;
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else if (y > x)
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return -1;
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x = XFS_RMAP_OFF(be64_to_cpu(kp->rm_offset));
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y = rec->rm_offset;
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if (x > y)
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return 1;
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else if (y > x)
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return -1;
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return 0;
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}
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STATIC int64_t
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xfs_rmapbt_diff_two_keys(
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struct xfs_btree_cur *cur,
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union xfs_btree_key *k1,
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union xfs_btree_key *k2)
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{
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struct xfs_rmap_key *kp1 = &k1->rmap;
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struct xfs_rmap_key *kp2 = &k2->rmap;
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int64_t d;
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__u64 x, y;
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d = (int64_t)be32_to_cpu(kp1->rm_startblock) -
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be32_to_cpu(kp2->rm_startblock);
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if (d)
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return d;
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x = be64_to_cpu(kp1->rm_owner);
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y = be64_to_cpu(kp2->rm_owner);
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if (x > y)
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return 1;
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else if (y > x)
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return -1;
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x = XFS_RMAP_OFF(be64_to_cpu(kp1->rm_offset));
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y = XFS_RMAP_OFF(be64_to_cpu(kp2->rm_offset));
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if (x > y)
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return 1;
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else if (y > x)
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return -1;
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return 0;
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}
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static xfs_failaddr_t
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xfs_rmapbt_verify(
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struct xfs_buf *bp)
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{
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struct xfs_mount *mp = bp->b_mount;
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struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
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struct xfs_perag *pag = bp->b_pag;
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xfs_failaddr_t fa;
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unsigned int level;
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/*
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* magic number and level verification
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*
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* During growfs operations, we can't verify the exact level or owner as
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* the perag is not fully initialised and hence not attached to the
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* buffer. In this case, check against the maximum tree depth.
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*
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* Similarly, during log recovery we will have a perag structure
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* attached, but the agf information will not yet have been initialised
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* from the on disk AGF. Again, we can only check against maximum limits
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* in this case.
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*/
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if (!xfs_verify_magic(bp, block->bb_magic))
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return __this_address;
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if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
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return __this_address;
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fa = xfs_btree_sblock_v5hdr_verify(bp);
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if (fa)
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return fa;
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level = be16_to_cpu(block->bb_level);
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if (pag && pag->pagf_init) {
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if (level >= pag->pagf_levels[XFS_BTNUM_RMAPi])
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return __this_address;
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} else if (level >= mp->m_rmap_maxlevels)
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return __this_address;
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return xfs_btree_sblock_verify(bp, mp->m_rmap_mxr[level != 0]);
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}
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static void
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xfs_rmapbt_read_verify(
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struct xfs_buf *bp)
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{
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xfs_failaddr_t fa;
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if (!xfs_btree_sblock_verify_crc(bp))
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xfs_verifier_error(bp, -EFSBADCRC, __this_address);
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else {
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fa = xfs_rmapbt_verify(bp);
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if (fa)
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xfs_verifier_error(bp, -EFSCORRUPTED, fa);
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}
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if (bp->b_error)
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trace_xfs_btree_corrupt(bp, _RET_IP_);
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}
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static void
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xfs_rmapbt_write_verify(
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struct xfs_buf *bp)
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{
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xfs_failaddr_t fa;
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fa = xfs_rmapbt_verify(bp);
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if (fa) {
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trace_xfs_btree_corrupt(bp, _RET_IP_);
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xfs_verifier_error(bp, -EFSCORRUPTED, fa);
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return;
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}
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xfs_btree_sblock_calc_crc(bp);
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}
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const struct xfs_buf_ops xfs_rmapbt_buf_ops = {
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.name = "xfs_rmapbt",
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.magic = { 0, cpu_to_be32(XFS_RMAP_CRC_MAGIC) },
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.verify_read = xfs_rmapbt_read_verify,
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.verify_write = xfs_rmapbt_write_verify,
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.verify_struct = xfs_rmapbt_verify,
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};
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STATIC int
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xfs_rmapbt_keys_inorder(
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struct xfs_btree_cur *cur,
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union xfs_btree_key *k1,
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union xfs_btree_key *k2)
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{
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uint32_t x;
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uint32_t y;
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uint64_t a;
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uint64_t b;
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x = be32_to_cpu(k1->rmap.rm_startblock);
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y = be32_to_cpu(k2->rmap.rm_startblock);
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if (x < y)
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return 1;
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else if (x > y)
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return 0;
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a = be64_to_cpu(k1->rmap.rm_owner);
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b = be64_to_cpu(k2->rmap.rm_owner);
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if (a < b)
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return 1;
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else if (a > b)
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return 0;
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a = XFS_RMAP_OFF(be64_to_cpu(k1->rmap.rm_offset));
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b = XFS_RMAP_OFF(be64_to_cpu(k2->rmap.rm_offset));
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if (a <= b)
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return 1;
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return 0;
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}
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STATIC int
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xfs_rmapbt_recs_inorder(
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struct xfs_btree_cur *cur,
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union xfs_btree_rec *r1,
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union xfs_btree_rec *r2)
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{
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uint32_t x;
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uint32_t y;
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uint64_t a;
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uint64_t b;
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x = be32_to_cpu(r1->rmap.rm_startblock);
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y = be32_to_cpu(r2->rmap.rm_startblock);
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if (x < y)
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return 1;
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else if (x > y)
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return 0;
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a = be64_to_cpu(r1->rmap.rm_owner);
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b = be64_to_cpu(r2->rmap.rm_owner);
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if (a < b)
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return 1;
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else if (a > b)
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return 0;
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a = XFS_RMAP_OFF(be64_to_cpu(r1->rmap.rm_offset));
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b = XFS_RMAP_OFF(be64_to_cpu(r2->rmap.rm_offset));
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if (a <= b)
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return 1;
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return 0;
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}
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static const struct xfs_btree_ops xfs_rmapbt_ops = {
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.rec_len = sizeof(struct xfs_rmap_rec),
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.key_len = 2 * sizeof(struct xfs_rmap_key),
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.dup_cursor = xfs_rmapbt_dup_cursor,
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.set_root = xfs_rmapbt_set_root,
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.alloc_block = xfs_rmapbt_alloc_block,
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.free_block = xfs_rmapbt_free_block,
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.get_minrecs = xfs_rmapbt_get_minrecs,
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.get_maxrecs = xfs_rmapbt_get_maxrecs,
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.init_key_from_rec = xfs_rmapbt_init_key_from_rec,
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.init_high_key_from_rec = xfs_rmapbt_init_high_key_from_rec,
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.init_rec_from_cur = xfs_rmapbt_init_rec_from_cur,
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.init_ptr_from_cur = xfs_rmapbt_init_ptr_from_cur,
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.key_diff = xfs_rmapbt_key_diff,
|
|
.buf_ops = &xfs_rmapbt_buf_ops,
|
|
.diff_two_keys = xfs_rmapbt_diff_two_keys,
|
|
.keys_inorder = xfs_rmapbt_keys_inorder,
|
|
.recs_inorder = xfs_rmapbt_recs_inorder,
|
|
};
|
|
|
|
static struct xfs_btree_cur *
|
|
xfs_rmapbt_init_common(
|
|
struct xfs_mount *mp,
|
|
struct xfs_trans *tp,
|
|
xfs_agnumber_t agno)
|
|
{
|
|
struct xfs_btree_cur *cur;
|
|
|
|
cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS);
|
|
cur->bc_tp = tp;
|
|
cur->bc_mp = mp;
|
|
/* Overlapping btree; 2 keys per pointer. */
|
|
cur->bc_btnum = XFS_BTNUM_RMAP;
|
|
cur->bc_flags = XFS_BTREE_CRC_BLOCKS | XFS_BTREE_OVERLAPPING;
|
|
cur->bc_blocklog = mp->m_sb.sb_blocklog;
|
|
cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_rmap_2);
|
|
cur->bc_ag.agno = agno;
|
|
cur->bc_ops = &xfs_rmapbt_ops;
|
|
|
|
return cur;
|
|
}
|
|
|
|
/* Create a new reverse mapping btree cursor. */
|
|
struct xfs_btree_cur *
|
|
xfs_rmapbt_init_cursor(
|
|
struct xfs_mount *mp,
|
|
struct xfs_trans *tp,
|
|
struct xfs_buf *agbp,
|
|
xfs_agnumber_t agno)
|
|
{
|
|
struct xfs_agf *agf = agbp->b_addr;
|
|
struct xfs_btree_cur *cur;
|
|
|
|
cur = xfs_rmapbt_init_common(mp, tp, agno);
|
|
cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]);
|
|
cur->bc_ag.agbp = agbp;
|
|
return cur;
|
|
}
|
|
|
|
/* Create a new reverse mapping btree cursor with a fake root for staging. */
|
|
struct xfs_btree_cur *
|
|
xfs_rmapbt_stage_cursor(
|
|
struct xfs_mount *mp,
|
|
struct xbtree_afakeroot *afake,
|
|
xfs_agnumber_t agno)
|
|
{
|
|
struct xfs_btree_cur *cur;
|
|
|
|
cur = xfs_rmapbt_init_common(mp, NULL, agno);
|
|
xfs_btree_stage_afakeroot(cur, afake);
|
|
return cur;
|
|
}
|
|
|
|
/*
|
|
* Install a new reverse mapping btree root. Caller is responsible for
|
|
* invalidating and freeing the old btree blocks.
|
|
*/
|
|
void
|
|
xfs_rmapbt_commit_staged_btree(
|
|
struct xfs_btree_cur *cur,
|
|
struct xfs_trans *tp,
|
|
struct xfs_buf *agbp)
|
|
{
|
|
struct xfs_agf *agf = agbp->b_addr;
|
|
struct xbtree_afakeroot *afake = cur->bc_ag.afake;
|
|
|
|
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
|
|
|
|
agf->agf_roots[cur->bc_btnum] = cpu_to_be32(afake->af_root);
|
|
agf->agf_levels[cur->bc_btnum] = cpu_to_be32(afake->af_levels);
|
|
agf->agf_rmap_blocks = cpu_to_be32(afake->af_blocks);
|
|
xfs_alloc_log_agf(tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS |
|
|
XFS_AGF_RMAP_BLOCKS);
|
|
xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_rmapbt_ops);
|
|
}
|
|
|
|
/*
|
|
* Calculate number of records in an rmap btree block.
|
|
*/
|
|
int
|
|
xfs_rmapbt_maxrecs(
|
|
int blocklen,
|
|
int leaf)
|
|
{
|
|
blocklen -= XFS_RMAP_BLOCK_LEN;
|
|
|
|
if (leaf)
|
|
return blocklen / sizeof(struct xfs_rmap_rec);
|
|
return blocklen /
|
|
(2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t));
|
|
}
|
|
|
|
/* Compute the maximum height of an rmap btree. */
|
|
void
|
|
xfs_rmapbt_compute_maxlevels(
|
|
struct xfs_mount *mp)
|
|
{
|
|
/*
|
|
* On a non-reflink filesystem, the maximum number of rmap
|
|
* records is the number of blocks in the AG, hence the max
|
|
* rmapbt height is log_$maxrecs($agblocks). However, with
|
|
* reflink each AG block can have up to 2^32 (per the refcount
|
|
* record format) owners, which means that theoretically we
|
|
* could face up to 2^64 rmap records.
|
|
*
|
|
* That effectively means that the max rmapbt height must be
|
|
* XFS_BTREE_MAXLEVELS. "Fortunately" we'll run out of AG
|
|
* blocks to feed the rmapbt long before the rmapbt reaches
|
|
* maximum height. The reflink code uses ag_resv_critical to
|
|
* disallow reflinking when less than 10% of the per-AG metadata
|
|
* block reservation since the fallback is a regular file copy.
|
|
*/
|
|
if (xfs_sb_version_hasreflink(&mp->m_sb))
|
|
mp->m_rmap_maxlevels = XFS_BTREE_MAXLEVELS;
|
|
else
|
|
mp->m_rmap_maxlevels = xfs_btree_compute_maxlevels(
|
|
mp->m_rmap_mnr, mp->m_sb.sb_agblocks);
|
|
}
|
|
|
|
/* Calculate the refcount btree size for some records. */
|
|
xfs_extlen_t
|
|
xfs_rmapbt_calc_size(
|
|
struct xfs_mount *mp,
|
|
unsigned long long len)
|
|
{
|
|
return xfs_btree_calc_size(mp->m_rmap_mnr, len);
|
|
}
|
|
|
|
/*
|
|
* Calculate the maximum refcount btree size.
|
|
*/
|
|
xfs_extlen_t
|
|
xfs_rmapbt_max_size(
|
|
struct xfs_mount *mp,
|
|
xfs_agblock_t agblocks)
|
|
{
|
|
/* Bail out if we're uninitialized, which can happen in mkfs. */
|
|
if (mp->m_rmap_mxr[0] == 0)
|
|
return 0;
|
|
|
|
return xfs_rmapbt_calc_size(mp, agblocks);
|
|
}
|
|
|
|
/*
|
|
* Figure out how many blocks to reserve and how many are used by this btree.
|
|
*/
|
|
int
|
|
xfs_rmapbt_calc_reserves(
|
|
struct xfs_mount *mp,
|
|
struct xfs_trans *tp,
|
|
xfs_agnumber_t agno,
|
|
xfs_extlen_t *ask,
|
|
xfs_extlen_t *used)
|
|
{
|
|
struct xfs_buf *agbp;
|
|
struct xfs_agf *agf;
|
|
xfs_agblock_t agblocks;
|
|
xfs_extlen_t tree_len;
|
|
int error;
|
|
|
|
if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
|
|
return 0;
|
|
|
|
error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
|
|
if (error)
|
|
return error;
|
|
|
|
agf = agbp->b_addr;
|
|
agblocks = be32_to_cpu(agf->agf_length);
|
|
tree_len = be32_to_cpu(agf->agf_rmap_blocks);
|
|
xfs_trans_brelse(tp, agbp);
|
|
|
|
/*
|
|
* The log is permanently allocated, so the space it occupies will
|
|
* never be available for the kinds of things that would require btree
|
|
* expansion. We therefore can pretend the space isn't there.
|
|
*/
|
|
if (mp->m_sb.sb_logstart &&
|
|
XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == agno)
|
|
agblocks -= mp->m_sb.sb_logblocks;
|
|
|
|
/* Reserve 1% of the AG or enough for 1 block per record. */
|
|
*ask += max(agblocks / 100, xfs_rmapbt_max_size(mp, agblocks));
|
|
*used += tree_len;
|
|
|
|
return error;
|
|
}
|