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1780 lines
47 KiB
1780 lines
47 KiB
// SPDX-License-Identifier: GPL-2.0+ |
|
/* |
|
* Copyright (C) 2016 Oracle. All Rights Reserved. |
|
* Author: Darrick J. Wong <[email protected]> |
|
*/ |
|
#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_mount.h" |
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#include "xfs_defer.h" |
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#include "xfs_btree.h" |
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#include "xfs_bmap.h" |
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#include "xfs_refcount_btree.h" |
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#include "xfs_alloc.h" |
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#include "xfs_errortag.h" |
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#include "xfs_error.h" |
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#include "xfs_trace.h" |
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#include "xfs_trans.h" |
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#include "xfs_bit.h" |
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#include "xfs_refcount.h" |
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#include "xfs_rmap.h" |
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|
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/* Allowable refcount adjustment amounts. */ |
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enum xfs_refc_adjust_op { |
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XFS_REFCOUNT_ADJUST_INCREASE = 1, |
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XFS_REFCOUNT_ADJUST_DECREASE = -1, |
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XFS_REFCOUNT_ADJUST_COW_ALLOC = 0, |
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XFS_REFCOUNT_ADJUST_COW_FREE = -1, |
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}; |
|
|
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STATIC int __xfs_refcount_cow_alloc(struct xfs_btree_cur *rcur, |
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xfs_agblock_t agbno, xfs_extlen_t aglen); |
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STATIC int __xfs_refcount_cow_free(struct xfs_btree_cur *rcur, |
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xfs_agblock_t agbno, xfs_extlen_t aglen); |
|
|
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/* |
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* Look up the first record less than or equal to [bno, len] in the btree |
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* given by cur. |
|
*/ |
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int |
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xfs_refcount_lookup_le( |
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struct xfs_btree_cur *cur, |
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xfs_agblock_t bno, |
|
int *stat) |
|
{ |
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trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_ag.agno, bno, |
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XFS_LOOKUP_LE); |
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cur->bc_rec.rc.rc_startblock = bno; |
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cur->bc_rec.rc.rc_blockcount = 0; |
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return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); |
|
} |
|
|
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/* |
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* Look up the first record greater than or equal to [bno, len] in the btree |
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* given by cur. |
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*/ |
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int |
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xfs_refcount_lookup_ge( |
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struct xfs_btree_cur *cur, |
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xfs_agblock_t bno, |
|
int *stat) |
|
{ |
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trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_ag.agno, bno, |
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XFS_LOOKUP_GE); |
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cur->bc_rec.rc.rc_startblock = bno; |
|
cur->bc_rec.rc.rc_blockcount = 0; |
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return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); |
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} |
|
|
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/* |
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* Look up the first record equal to [bno, len] in the btree |
|
* given by cur. |
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*/ |
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int |
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xfs_refcount_lookup_eq( |
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struct xfs_btree_cur *cur, |
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xfs_agblock_t bno, |
|
int *stat) |
|
{ |
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trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_ag.agno, bno, |
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XFS_LOOKUP_LE); |
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cur->bc_rec.rc.rc_startblock = bno; |
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cur->bc_rec.rc.rc_blockcount = 0; |
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return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat); |
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} |
|
|
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/* Convert on-disk record to in-core format. */ |
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void |
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xfs_refcount_btrec_to_irec( |
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union xfs_btree_rec *rec, |
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struct xfs_refcount_irec *irec) |
|
{ |
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irec->rc_startblock = be32_to_cpu(rec->refc.rc_startblock); |
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irec->rc_blockcount = be32_to_cpu(rec->refc.rc_blockcount); |
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irec->rc_refcount = be32_to_cpu(rec->refc.rc_refcount); |
|
} |
|
|
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/* |
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* Get the data from the pointed-to record. |
|
*/ |
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int |
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xfs_refcount_get_rec( |
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struct xfs_btree_cur *cur, |
|
struct xfs_refcount_irec *irec, |
|
int *stat) |
|
{ |
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struct xfs_mount *mp = cur->bc_mp; |
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xfs_agnumber_t agno = cur->bc_ag.agno; |
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union xfs_btree_rec *rec; |
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int error; |
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xfs_agblock_t realstart; |
|
|
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error = xfs_btree_get_rec(cur, &rec, stat); |
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if (error || !*stat) |
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return error; |
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|
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xfs_refcount_btrec_to_irec(rec, irec); |
|
|
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agno = cur->bc_ag.agno; |
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if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN) |
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goto out_bad_rec; |
|
|
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/* handle special COW-staging state */ |
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realstart = irec->rc_startblock; |
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if (realstart & XFS_REFC_COW_START) { |
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if (irec->rc_refcount != 1) |
|
goto out_bad_rec; |
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realstart &= ~XFS_REFC_COW_START; |
|
} else if (irec->rc_refcount < 2) { |
|
goto out_bad_rec; |
|
} |
|
|
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/* check for valid extent range, including overflow */ |
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if (!xfs_verify_agbno(mp, agno, realstart)) |
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goto out_bad_rec; |
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if (realstart > realstart + irec->rc_blockcount) |
|
goto out_bad_rec; |
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if (!xfs_verify_agbno(mp, agno, realstart + irec->rc_blockcount - 1)) |
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goto out_bad_rec; |
|
|
|
if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT) |
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goto out_bad_rec; |
|
|
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trace_xfs_refcount_get(cur->bc_mp, cur->bc_ag.agno, irec); |
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return 0; |
|
|
|
out_bad_rec: |
|
xfs_warn(mp, |
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"Refcount BTree record corruption in AG %d detected!", agno); |
|
xfs_warn(mp, |
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"Start block 0x%x, block count 0x%x, references 0x%x", |
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irec->rc_startblock, irec->rc_blockcount, irec->rc_refcount); |
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return -EFSCORRUPTED; |
|
} |
|
|
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/* |
|
* Update the record referred to by cur to the value given |
|
* by [bno, len, refcount]. |
|
* This either works (return 0) or gets an EFSCORRUPTED error. |
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*/ |
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STATIC int |
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xfs_refcount_update( |
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struct xfs_btree_cur *cur, |
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struct xfs_refcount_irec *irec) |
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{ |
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union xfs_btree_rec rec; |
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int error; |
|
|
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trace_xfs_refcount_update(cur->bc_mp, cur->bc_ag.agno, irec); |
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rec.refc.rc_startblock = cpu_to_be32(irec->rc_startblock); |
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rec.refc.rc_blockcount = cpu_to_be32(irec->rc_blockcount); |
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rec.refc.rc_refcount = cpu_to_be32(irec->rc_refcount); |
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error = xfs_btree_update(cur, &rec); |
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if (error) |
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trace_xfs_refcount_update_error(cur->bc_mp, |
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cur->bc_ag.agno, error, _RET_IP_); |
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return error; |
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} |
|
|
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/* |
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* Insert the record referred to by cur to the value given |
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* by [bno, len, refcount]. |
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* This either works (return 0) or gets an EFSCORRUPTED error. |
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*/ |
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int |
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xfs_refcount_insert( |
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struct xfs_btree_cur *cur, |
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struct xfs_refcount_irec *irec, |
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int *i) |
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{ |
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int error; |
|
|
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trace_xfs_refcount_insert(cur->bc_mp, cur->bc_ag.agno, irec); |
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cur->bc_rec.rc.rc_startblock = irec->rc_startblock; |
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cur->bc_rec.rc.rc_blockcount = irec->rc_blockcount; |
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cur->bc_rec.rc.rc_refcount = irec->rc_refcount; |
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error = xfs_btree_insert(cur, i); |
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if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, *i != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
out_error: |
|
if (error) |
|
trace_xfs_refcount_insert_error(cur->bc_mp, |
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cur->bc_ag.agno, error, _RET_IP_); |
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return error; |
|
} |
|
|
|
/* |
|
* Remove the record referred to by cur, then set the pointer to the spot |
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* where the record could be re-inserted, in case we want to increment or |
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* decrement the cursor. |
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* This either works (return 0) or gets an EFSCORRUPTED error. |
|
*/ |
|
STATIC int |
|
xfs_refcount_delete( |
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struct xfs_btree_cur *cur, |
|
int *i) |
|
{ |
|
struct xfs_refcount_irec irec; |
|
int found_rec; |
|
int error; |
|
|
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error = xfs_refcount_get_rec(cur, &irec, &found_rec); |
|
if (error) |
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goto out_error; |
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if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
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error = -EFSCORRUPTED; |
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goto out_error; |
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} |
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trace_xfs_refcount_delete(cur->bc_mp, cur->bc_ag.agno, &irec); |
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error = xfs_btree_delete(cur, i); |
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if (XFS_IS_CORRUPT(cur->bc_mp, *i != 1)) { |
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error = -EFSCORRUPTED; |
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goto out_error; |
|
} |
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if (error) |
|
goto out_error; |
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error = xfs_refcount_lookup_ge(cur, irec.rc_startblock, &found_rec); |
|
out_error: |
|
if (error) |
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trace_xfs_refcount_delete_error(cur->bc_mp, |
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cur->bc_ag.agno, error, _RET_IP_); |
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return error; |
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} |
|
|
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/* |
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* Adjusting the Reference Count |
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* |
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* As stated elsewhere, the reference count btree (refcbt) stores |
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* >1 reference counts for extents of physical blocks. In this |
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* operation, we're either raising or lowering the reference count of |
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* some subrange stored in the tree: |
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* |
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* <------ adjustment range ------> |
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* ----+ +---+-----+ +--+--------+--------- |
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* 2 | | 3 | 4 | |17| 55 | 10 |
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* ----+ +---+-----+ +--+--------+--------- |
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* X axis is physical blocks number; |
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* reference counts are the numbers inside the rectangles |
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* |
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* The first thing we need to do is to ensure that there are no |
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* refcount extents crossing either boundary of the range to be |
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* adjusted. For any extent that does cross a boundary, split it into |
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* two extents so that we can increment the refcount of one of the |
|
* pieces later: |
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* |
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* <------ adjustment range ------> |
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* ----+ +---+-----+ +--+--------+----+---- |
|
* 2 | | 3 | 2 | |17| 55 | 10 | 10 |
|
* ----+ +---+-----+ +--+--------+----+---- |
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* |
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* For this next step, let's assume that all the physical blocks in |
|
* the adjustment range are mapped to a file and are therefore in use |
|
* at least once. Therefore, we can infer that any gap in the |
|
* refcount tree within the adjustment range represents a physical |
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* extent with refcount == 1: |
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* |
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* <------ adjustment range ------> |
|
* ----+---+---+-----+-+--+--------+----+---- |
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* 2 |"1"| 3 | 2 |1|17| 55 | 10 | 10 |
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* ----+---+---+-----+-+--+--------+----+---- |
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* ^ |
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* |
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* For each extent that falls within the interval range, figure out |
|
* which extent is to the left or the right of that extent. Now we |
|
* have a left, current, and right extent. If the new reference count |
|
* of the center extent enables us to merge left, center, and right |
|
* into one record covering all three, do so. If the center extent is |
|
* at the left end of the range, abuts the left extent, and its new |
|
* reference count matches the left extent's record, then merge them. |
|
* If the center extent is at the right end of the range, abuts the |
|
* right extent, and the reference counts match, merge those. In the |
|
* example, we can left merge (assuming an increment operation): |
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* |
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* <------ adjustment range ------> |
|
* --------+---+-----+-+--+--------+----+---- |
|
* 2 | 3 | 2 |1|17| 55 | 10 | 10 |
|
* --------+---+-----+-+--+--------+----+---- |
|
* ^ |
|
* |
|
* For all other extents within the range, adjust the reference count |
|
* or delete it if the refcount falls below 2. If we were |
|
* incrementing, the end result looks like this: |
|
* |
|
* <------ adjustment range ------> |
|
* --------+---+-----+-+--+--------+----+---- |
|
* 2 | 4 | 3 |2|18| 56 | 11 | 10 |
|
* --------+---+-----+-+--+--------+----+---- |
|
* |
|
* The result of a decrement operation looks as such: |
|
* |
|
* <------ adjustment range ------> |
|
* ----+ +---+ +--+--------+----+---- |
|
* 2 | | 2 | |16| 54 | 9 | 10 |
|
* ----+ +---+ +--+--------+----+---- |
|
* DDDD 111111DD |
|
* |
|
* The blocks marked "D" are freed; the blocks marked "1" are only |
|
* referenced once and therefore the record is removed from the |
|
* refcount btree. |
|
*/ |
|
|
|
/* Next block after this extent. */ |
|
static inline xfs_agblock_t |
|
xfs_refc_next( |
|
struct xfs_refcount_irec *rc) |
|
{ |
|
return rc->rc_startblock + rc->rc_blockcount; |
|
} |
|
|
|
/* |
|
* Split a refcount extent that crosses agbno. |
|
*/ |
|
STATIC int |
|
xfs_refcount_split_extent( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t agbno, |
|
bool *shape_changed) |
|
{ |
|
struct xfs_refcount_irec rcext, tmp; |
|
int found_rec; |
|
int error; |
|
|
|
*shape_changed = false; |
|
error = xfs_refcount_lookup_le(cur, agbno, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (!found_rec) |
|
return 0; |
|
|
|
error = xfs_refcount_get_rec(cur, &rcext, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
if (rcext.rc_startblock == agbno || xfs_refc_next(&rcext) <= agbno) |
|
return 0; |
|
|
|
*shape_changed = true; |
|
trace_xfs_refcount_split_extent(cur->bc_mp, cur->bc_ag.agno, |
|
&rcext, agbno); |
|
|
|
/* Establish the right extent. */ |
|
tmp = rcext; |
|
tmp.rc_startblock = agbno; |
|
tmp.rc_blockcount -= (agbno - rcext.rc_startblock); |
|
error = xfs_refcount_update(cur, &tmp); |
|
if (error) |
|
goto out_error; |
|
|
|
/* Insert the left extent. */ |
|
tmp = rcext; |
|
tmp.rc_blockcount = agbno - rcext.rc_startblock; |
|
error = xfs_refcount_insert(cur, &tmp, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
return error; |
|
|
|
out_error: |
|
trace_xfs_refcount_split_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Merge the left, center, and right extents. |
|
*/ |
|
STATIC int |
|
xfs_refcount_merge_center_extents( |
|
struct xfs_btree_cur *cur, |
|
struct xfs_refcount_irec *left, |
|
struct xfs_refcount_irec *center, |
|
struct xfs_refcount_irec *right, |
|
unsigned long long extlen, |
|
xfs_extlen_t *aglen) |
|
{ |
|
int error; |
|
int found_rec; |
|
|
|
trace_xfs_refcount_merge_center_extents(cur->bc_mp, |
|
cur->bc_ag.agno, left, center, right); |
|
|
|
/* |
|
* Make sure the center and right extents are not in the btree. |
|
* If the center extent was synthesized, the first delete call |
|
* removes the right extent and we skip the second deletion. |
|
* If center and right were in the btree, then the first delete |
|
* call removes the center and the second one removes the right |
|
* extent. |
|
*/ |
|
error = xfs_refcount_lookup_ge(cur, center->rc_startblock, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
error = xfs_refcount_delete(cur, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
if (center->rc_refcount > 1) { |
|
error = xfs_refcount_delete(cur, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
} |
|
|
|
/* Enlarge the left extent. */ |
|
error = xfs_refcount_lookup_le(cur, left->rc_startblock, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
left->rc_blockcount = extlen; |
|
error = xfs_refcount_update(cur, left); |
|
if (error) |
|
goto out_error; |
|
|
|
*aglen = 0; |
|
return error; |
|
|
|
out_error: |
|
trace_xfs_refcount_merge_center_extents_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Merge with the left extent. |
|
*/ |
|
STATIC int |
|
xfs_refcount_merge_left_extent( |
|
struct xfs_btree_cur *cur, |
|
struct xfs_refcount_irec *left, |
|
struct xfs_refcount_irec *cleft, |
|
xfs_agblock_t *agbno, |
|
xfs_extlen_t *aglen) |
|
{ |
|
int error; |
|
int found_rec; |
|
|
|
trace_xfs_refcount_merge_left_extent(cur->bc_mp, |
|
cur->bc_ag.agno, left, cleft); |
|
|
|
/* If the extent at agbno (cleft) wasn't synthesized, remove it. */ |
|
if (cleft->rc_refcount > 1) { |
|
error = xfs_refcount_lookup_le(cur, cleft->rc_startblock, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
error = xfs_refcount_delete(cur, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
} |
|
|
|
/* Enlarge the left extent. */ |
|
error = xfs_refcount_lookup_le(cur, left->rc_startblock, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
left->rc_blockcount += cleft->rc_blockcount; |
|
error = xfs_refcount_update(cur, left); |
|
if (error) |
|
goto out_error; |
|
|
|
*agbno += cleft->rc_blockcount; |
|
*aglen -= cleft->rc_blockcount; |
|
return error; |
|
|
|
out_error: |
|
trace_xfs_refcount_merge_left_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Merge with the right extent. |
|
*/ |
|
STATIC int |
|
xfs_refcount_merge_right_extent( |
|
struct xfs_btree_cur *cur, |
|
struct xfs_refcount_irec *right, |
|
struct xfs_refcount_irec *cright, |
|
xfs_extlen_t *aglen) |
|
{ |
|
int error; |
|
int found_rec; |
|
|
|
trace_xfs_refcount_merge_right_extent(cur->bc_mp, |
|
cur->bc_ag.agno, cright, right); |
|
|
|
/* |
|
* If the extent ending at agbno+aglen (cright) wasn't synthesized, |
|
* remove it. |
|
*/ |
|
if (cright->rc_refcount > 1) { |
|
error = xfs_refcount_lookup_le(cur, cright->rc_startblock, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
error = xfs_refcount_delete(cur, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
} |
|
|
|
/* Enlarge the right extent. */ |
|
error = xfs_refcount_lookup_le(cur, right->rc_startblock, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
right->rc_startblock -= cright->rc_blockcount; |
|
right->rc_blockcount += cright->rc_blockcount; |
|
error = xfs_refcount_update(cur, right); |
|
if (error) |
|
goto out_error; |
|
|
|
*aglen -= cright->rc_blockcount; |
|
return error; |
|
|
|
out_error: |
|
trace_xfs_refcount_merge_right_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
#define XFS_FIND_RCEXT_SHARED 1 |
|
#define XFS_FIND_RCEXT_COW 2 |
|
/* |
|
* Find the left extent and the one after it (cleft). This function assumes |
|
* that we've already split any extent crossing agbno. |
|
*/ |
|
STATIC int |
|
xfs_refcount_find_left_extents( |
|
struct xfs_btree_cur *cur, |
|
struct xfs_refcount_irec *left, |
|
struct xfs_refcount_irec *cleft, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen, |
|
int flags) |
|
{ |
|
struct xfs_refcount_irec tmp; |
|
int error; |
|
int found_rec; |
|
|
|
left->rc_startblock = cleft->rc_startblock = NULLAGBLOCK; |
|
error = xfs_refcount_lookup_le(cur, agbno - 1, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (!found_rec) |
|
return 0; |
|
|
|
error = xfs_refcount_get_rec(cur, &tmp, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
if (xfs_refc_next(&tmp) != agbno) |
|
return 0; |
|
if ((flags & XFS_FIND_RCEXT_SHARED) && tmp.rc_refcount < 2) |
|
return 0; |
|
if ((flags & XFS_FIND_RCEXT_COW) && tmp.rc_refcount > 1) |
|
return 0; |
|
/* We have a left extent; retrieve (or invent) the next right one */ |
|
*left = tmp; |
|
|
|
error = xfs_btree_increment(cur, 0, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (found_rec) { |
|
error = xfs_refcount_get_rec(cur, &tmp, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
/* if tmp starts at the end of our range, just use that */ |
|
if (tmp.rc_startblock == agbno) |
|
*cleft = tmp; |
|
else { |
|
/* |
|
* There's a gap in the refcntbt at the start of the |
|
* range we're interested in (refcount == 1) so |
|
* synthesize the implied extent and pass it back. |
|
* We assume here that the agbno/aglen range was |
|
* passed in from a data fork extent mapping and |
|
* therefore is allocated to exactly one owner. |
|
*/ |
|
cleft->rc_startblock = agbno; |
|
cleft->rc_blockcount = min(aglen, |
|
tmp.rc_startblock - agbno); |
|
cleft->rc_refcount = 1; |
|
} |
|
} else { |
|
/* |
|
* No extents, so pretend that there's one covering the whole |
|
* range. |
|
*/ |
|
cleft->rc_startblock = agbno; |
|
cleft->rc_blockcount = aglen; |
|
cleft->rc_refcount = 1; |
|
} |
|
trace_xfs_refcount_find_left_extent(cur->bc_mp, cur->bc_ag.agno, |
|
left, cleft, agbno); |
|
return error; |
|
|
|
out_error: |
|
trace_xfs_refcount_find_left_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Find the right extent and the one before it (cright). This function |
|
* assumes that we've already split any extents crossing agbno + aglen. |
|
*/ |
|
STATIC int |
|
xfs_refcount_find_right_extents( |
|
struct xfs_btree_cur *cur, |
|
struct xfs_refcount_irec *right, |
|
struct xfs_refcount_irec *cright, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen, |
|
int flags) |
|
{ |
|
struct xfs_refcount_irec tmp; |
|
int error; |
|
int found_rec; |
|
|
|
right->rc_startblock = cright->rc_startblock = NULLAGBLOCK; |
|
error = xfs_refcount_lookup_ge(cur, agbno + aglen, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (!found_rec) |
|
return 0; |
|
|
|
error = xfs_refcount_get_rec(cur, &tmp, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
if (tmp.rc_startblock != agbno + aglen) |
|
return 0; |
|
if ((flags & XFS_FIND_RCEXT_SHARED) && tmp.rc_refcount < 2) |
|
return 0; |
|
if ((flags & XFS_FIND_RCEXT_COW) && tmp.rc_refcount > 1) |
|
return 0; |
|
/* We have a right extent; retrieve (or invent) the next left one */ |
|
*right = tmp; |
|
|
|
error = xfs_btree_decrement(cur, 0, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (found_rec) { |
|
error = xfs_refcount_get_rec(cur, &tmp, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
/* if tmp ends at the end of our range, just use that */ |
|
if (xfs_refc_next(&tmp) == agbno + aglen) |
|
*cright = tmp; |
|
else { |
|
/* |
|
* There's a gap in the refcntbt at the end of the |
|
* range we're interested in (refcount == 1) so |
|
* create the implied extent and pass it back. |
|
* We assume here that the agbno/aglen range was |
|
* passed in from a data fork extent mapping and |
|
* therefore is allocated to exactly one owner. |
|
*/ |
|
cright->rc_startblock = max(agbno, xfs_refc_next(&tmp)); |
|
cright->rc_blockcount = right->rc_startblock - |
|
cright->rc_startblock; |
|
cright->rc_refcount = 1; |
|
} |
|
} else { |
|
/* |
|
* No extents, so pretend that there's one covering the whole |
|
* range. |
|
*/ |
|
cright->rc_startblock = agbno; |
|
cright->rc_blockcount = aglen; |
|
cright->rc_refcount = 1; |
|
} |
|
trace_xfs_refcount_find_right_extent(cur->bc_mp, cur->bc_ag.agno, |
|
cright, right, agbno + aglen); |
|
return error; |
|
|
|
out_error: |
|
trace_xfs_refcount_find_right_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* Is this extent valid? */ |
|
static inline bool |
|
xfs_refc_valid( |
|
struct xfs_refcount_irec *rc) |
|
{ |
|
return rc->rc_startblock != NULLAGBLOCK; |
|
} |
|
|
|
/* |
|
* Try to merge with any extents on the boundaries of the adjustment range. |
|
*/ |
|
STATIC int |
|
xfs_refcount_merge_extents( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t *agbno, |
|
xfs_extlen_t *aglen, |
|
enum xfs_refc_adjust_op adjust, |
|
int flags, |
|
bool *shape_changed) |
|
{ |
|
struct xfs_refcount_irec left = {0}, cleft = {0}; |
|
struct xfs_refcount_irec cright = {0}, right = {0}; |
|
int error; |
|
unsigned long long ulen; |
|
bool cequal; |
|
|
|
*shape_changed = false; |
|
/* |
|
* Find the extent just below agbno [left], just above agbno [cleft], |
|
* just below (agbno + aglen) [cright], and just above (agbno + aglen) |
|
* [right]. |
|
*/ |
|
error = xfs_refcount_find_left_extents(cur, &left, &cleft, *agbno, |
|
*aglen, flags); |
|
if (error) |
|
return error; |
|
error = xfs_refcount_find_right_extents(cur, &right, &cright, *agbno, |
|
*aglen, flags); |
|
if (error) |
|
return error; |
|
|
|
/* No left or right extent to merge; exit. */ |
|
if (!xfs_refc_valid(&left) && !xfs_refc_valid(&right)) |
|
return 0; |
|
|
|
cequal = (cleft.rc_startblock == cright.rc_startblock) && |
|
(cleft.rc_blockcount == cright.rc_blockcount); |
|
|
|
/* Try to merge left, cleft, and right. cleft must == cright. */ |
|
ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount + |
|
right.rc_blockcount; |
|
if (xfs_refc_valid(&left) && xfs_refc_valid(&right) && |
|
xfs_refc_valid(&cleft) && xfs_refc_valid(&cright) && cequal && |
|
left.rc_refcount == cleft.rc_refcount + adjust && |
|
right.rc_refcount == cleft.rc_refcount + adjust && |
|
ulen < MAXREFCEXTLEN) { |
|
*shape_changed = true; |
|
return xfs_refcount_merge_center_extents(cur, &left, &cleft, |
|
&right, ulen, aglen); |
|
} |
|
|
|
/* Try to merge left and cleft. */ |
|
ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount; |
|
if (xfs_refc_valid(&left) && xfs_refc_valid(&cleft) && |
|
left.rc_refcount == cleft.rc_refcount + adjust && |
|
ulen < MAXREFCEXTLEN) { |
|
*shape_changed = true; |
|
error = xfs_refcount_merge_left_extent(cur, &left, &cleft, |
|
agbno, aglen); |
|
if (error) |
|
return error; |
|
|
|
/* |
|
* If we just merged left + cleft and cleft == cright, |
|
* we no longer have a cright to merge with right. We're done. |
|
*/ |
|
if (cequal) |
|
return 0; |
|
} |
|
|
|
/* Try to merge cright and right. */ |
|
ulen = (unsigned long long)right.rc_blockcount + cright.rc_blockcount; |
|
if (xfs_refc_valid(&right) && xfs_refc_valid(&cright) && |
|
right.rc_refcount == cright.rc_refcount + adjust && |
|
ulen < MAXREFCEXTLEN) { |
|
*shape_changed = true; |
|
return xfs_refcount_merge_right_extent(cur, &right, &cright, |
|
aglen); |
|
} |
|
|
|
return error; |
|
} |
|
|
|
/* |
|
* XXX: This is a pretty hand-wavy estimate. The penalty for guessing |
|
* true incorrectly is a shutdown FS; the penalty for guessing false |
|
* incorrectly is more transaction rolls than might be necessary. |
|
* Be conservative here. |
|
*/ |
|
static bool |
|
xfs_refcount_still_have_space( |
|
struct xfs_btree_cur *cur) |
|
{ |
|
unsigned long overhead; |
|
|
|
overhead = cur->bc_ag.refc.shape_changes * |
|
xfs_allocfree_log_count(cur->bc_mp, 1); |
|
overhead *= cur->bc_mp->m_sb.sb_blocksize; |
|
|
|
/* |
|
* Only allow 2 refcount extent updates per transaction if the |
|
* refcount continue update "error" has been injected. |
|
*/ |
|
if (cur->bc_ag.refc.nr_ops > 2 && |
|
XFS_TEST_ERROR(false, cur->bc_mp, |
|
XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE)) |
|
return false; |
|
|
|
if (cur->bc_ag.refc.nr_ops == 0) |
|
return true; |
|
else if (overhead > cur->bc_tp->t_log_res) |
|
return false; |
|
return cur->bc_tp->t_log_res - overhead > |
|
cur->bc_ag.refc.nr_ops * XFS_REFCOUNT_ITEM_OVERHEAD; |
|
} |
|
|
|
/* |
|
* Adjust the refcounts of middle extents. At this point we should have |
|
* split extents that crossed the adjustment range; merged with adjacent |
|
* extents; and updated agbno/aglen to reflect the merges. Therefore, |
|
* all we have to do is update the extents inside [agbno, agbno + aglen]. |
|
*/ |
|
STATIC int |
|
xfs_refcount_adjust_extents( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t *agbno, |
|
xfs_extlen_t *aglen, |
|
enum xfs_refc_adjust_op adj, |
|
struct xfs_owner_info *oinfo) |
|
{ |
|
struct xfs_refcount_irec ext, tmp; |
|
int error; |
|
int found_rec, found_tmp; |
|
xfs_fsblock_t fsbno; |
|
|
|
/* Merging did all the work already. */ |
|
if (*aglen == 0) |
|
return 0; |
|
|
|
error = xfs_refcount_lookup_ge(cur, *agbno, &found_rec); |
|
if (error) |
|
goto out_error; |
|
|
|
while (*aglen > 0 && xfs_refcount_still_have_space(cur)) { |
|
error = xfs_refcount_get_rec(cur, &ext, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (!found_rec) { |
|
ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks; |
|
ext.rc_blockcount = 0; |
|
ext.rc_refcount = 0; |
|
} |
|
|
|
/* |
|
* Deal with a hole in the refcount tree; if a file maps to |
|
* these blocks and there's no refcountbt record, pretend that |
|
* there is one with refcount == 1. |
|
*/ |
|
if (ext.rc_startblock != *agbno) { |
|
tmp.rc_startblock = *agbno; |
|
tmp.rc_blockcount = min(*aglen, |
|
ext.rc_startblock - *agbno); |
|
tmp.rc_refcount = 1 + adj; |
|
trace_xfs_refcount_modify_extent(cur->bc_mp, |
|
cur->bc_ag.agno, &tmp); |
|
|
|
/* |
|
* Either cover the hole (increment) or |
|
* delete the range (decrement). |
|
*/ |
|
if (tmp.rc_refcount) { |
|
error = xfs_refcount_insert(cur, &tmp, |
|
&found_tmp); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, |
|
found_tmp != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
cur->bc_ag.refc.nr_ops++; |
|
} else { |
|
fsbno = XFS_AGB_TO_FSB(cur->bc_mp, |
|
cur->bc_ag.agno, |
|
tmp.rc_startblock); |
|
xfs_bmap_add_free(cur->bc_tp, fsbno, |
|
tmp.rc_blockcount, oinfo); |
|
} |
|
|
|
(*agbno) += tmp.rc_blockcount; |
|
(*aglen) -= tmp.rc_blockcount; |
|
|
|
error = xfs_refcount_lookup_ge(cur, *agbno, |
|
&found_rec); |
|
if (error) |
|
goto out_error; |
|
} |
|
|
|
/* Stop if there's nothing left to modify */ |
|
if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) |
|
break; |
|
|
|
/* |
|
* Adjust the reference count and either update the tree |
|
* (incr) or free the blocks (decr). |
|
*/ |
|
if (ext.rc_refcount == MAXREFCOUNT) |
|
goto skip; |
|
ext.rc_refcount += adj; |
|
trace_xfs_refcount_modify_extent(cur->bc_mp, |
|
cur->bc_ag.agno, &ext); |
|
if (ext.rc_refcount > 1) { |
|
error = xfs_refcount_update(cur, &ext); |
|
if (error) |
|
goto out_error; |
|
cur->bc_ag.refc.nr_ops++; |
|
} else if (ext.rc_refcount == 1) { |
|
error = xfs_refcount_delete(cur, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
cur->bc_ag.refc.nr_ops++; |
|
goto advloop; |
|
} else { |
|
fsbno = XFS_AGB_TO_FSB(cur->bc_mp, |
|
cur->bc_ag.agno, |
|
ext.rc_startblock); |
|
xfs_bmap_add_free(cur->bc_tp, fsbno, ext.rc_blockcount, |
|
oinfo); |
|
} |
|
|
|
skip: |
|
error = xfs_btree_increment(cur, 0, &found_rec); |
|
if (error) |
|
goto out_error; |
|
|
|
advloop: |
|
(*agbno) += ext.rc_blockcount; |
|
(*aglen) -= ext.rc_blockcount; |
|
} |
|
|
|
return error; |
|
out_error: |
|
trace_xfs_refcount_modify_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* Adjust the reference count of a range of AG blocks. */ |
|
STATIC int |
|
xfs_refcount_adjust( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen, |
|
xfs_agblock_t *new_agbno, |
|
xfs_extlen_t *new_aglen, |
|
enum xfs_refc_adjust_op adj, |
|
struct xfs_owner_info *oinfo) |
|
{ |
|
bool shape_changed; |
|
int shape_changes = 0; |
|
int error; |
|
|
|
*new_agbno = agbno; |
|
*new_aglen = aglen; |
|
if (adj == XFS_REFCOUNT_ADJUST_INCREASE) |
|
trace_xfs_refcount_increase(cur->bc_mp, cur->bc_ag.agno, |
|
agbno, aglen); |
|
else |
|
trace_xfs_refcount_decrease(cur->bc_mp, cur->bc_ag.agno, |
|
agbno, aglen); |
|
|
|
/* |
|
* Ensure that no rcextents cross the boundary of the adjustment range. |
|
*/ |
|
error = xfs_refcount_split_extent(cur, agbno, &shape_changed); |
|
if (error) |
|
goto out_error; |
|
if (shape_changed) |
|
shape_changes++; |
|
|
|
error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); |
|
if (error) |
|
goto out_error; |
|
if (shape_changed) |
|
shape_changes++; |
|
|
|
/* |
|
* Try to merge with the left or right extents of the range. |
|
*/ |
|
error = xfs_refcount_merge_extents(cur, new_agbno, new_aglen, adj, |
|
XFS_FIND_RCEXT_SHARED, &shape_changed); |
|
if (error) |
|
goto out_error; |
|
if (shape_changed) |
|
shape_changes++; |
|
if (shape_changes) |
|
cur->bc_ag.refc.shape_changes++; |
|
|
|
/* Now that we've taken care of the ends, adjust the middle extents */ |
|
error = xfs_refcount_adjust_extents(cur, new_agbno, new_aglen, |
|
adj, oinfo); |
|
if (error) |
|
goto out_error; |
|
|
|
return 0; |
|
|
|
out_error: |
|
trace_xfs_refcount_adjust_error(cur->bc_mp, cur->bc_ag.agno, |
|
error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* Clean up after calling xfs_refcount_finish_one. */ |
|
void |
|
xfs_refcount_finish_one_cleanup( |
|
struct xfs_trans *tp, |
|
struct xfs_btree_cur *rcur, |
|
int error) |
|
{ |
|
struct xfs_buf *agbp; |
|
|
|
if (rcur == NULL) |
|
return; |
|
agbp = rcur->bc_ag.agbp; |
|
xfs_btree_del_cursor(rcur, error); |
|
if (error) |
|
xfs_trans_brelse(tp, agbp); |
|
} |
|
|
|
/* |
|
* Process one of the deferred refcount operations. We pass back the |
|
* btree cursor to maintain our lock on the btree between calls. |
|
* This saves time and eliminates a buffer deadlock between the |
|
* superblock and the AGF because we'll always grab them in the same |
|
* order. |
|
*/ |
|
int |
|
xfs_refcount_finish_one( |
|
struct xfs_trans *tp, |
|
enum xfs_refcount_intent_type type, |
|
xfs_fsblock_t startblock, |
|
xfs_extlen_t blockcount, |
|
xfs_fsblock_t *new_fsb, |
|
xfs_extlen_t *new_len, |
|
struct xfs_btree_cur **pcur) |
|
{ |
|
struct xfs_mount *mp = tp->t_mountp; |
|
struct xfs_btree_cur *rcur; |
|
struct xfs_buf *agbp = NULL; |
|
int error = 0; |
|
xfs_agnumber_t agno; |
|
xfs_agblock_t bno; |
|
xfs_agblock_t new_agbno; |
|
unsigned long nr_ops = 0; |
|
int shape_changes = 0; |
|
|
|
agno = XFS_FSB_TO_AGNO(mp, startblock); |
|
ASSERT(agno != NULLAGNUMBER); |
|
bno = XFS_FSB_TO_AGBNO(mp, startblock); |
|
|
|
trace_xfs_refcount_deferred(mp, XFS_FSB_TO_AGNO(mp, startblock), |
|
type, XFS_FSB_TO_AGBNO(mp, startblock), |
|
blockcount); |
|
|
|
if (XFS_TEST_ERROR(false, mp, |
|
XFS_ERRTAG_REFCOUNT_FINISH_ONE)) |
|
return -EIO; |
|
|
|
/* |
|
* If we haven't gotten a cursor or the cursor AG doesn't match |
|
* the startblock, get one now. |
|
*/ |
|
rcur = *pcur; |
|
if (rcur != NULL && rcur->bc_ag.agno != agno) { |
|
nr_ops = rcur->bc_ag.refc.nr_ops; |
|
shape_changes = rcur->bc_ag.refc.shape_changes; |
|
xfs_refcount_finish_one_cleanup(tp, rcur, 0); |
|
rcur = NULL; |
|
*pcur = NULL; |
|
} |
|
if (rcur == NULL) { |
|
error = xfs_alloc_read_agf(tp->t_mountp, tp, agno, |
|
XFS_ALLOC_FLAG_FREEING, &agbp); |
|
if (error) |
|
return error; |
|
|
|
rcur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno); |
|
rcur->bc_ag.refc.nr_ops = nr_ops; |
|
rcur->bc_ag.refc.shape_changes = shape_changes; |
|
} |
|
*pcur = rcur; |
|
|
|
switch (type) { |
|
case XFS_REFCOUNT_INCREASE: |
|
error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, |
|
new_len, XFS_REFCOUNT_ADJUST_INCREASE, NULL); |
|
*new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); |
|
break; |
|
case XFS_REFCOUNT_DECREASE: |
|
error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, |
|
new_len, XFS_REFCOUNT_ADJUST_DECREASE, NULL); |
|
*new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); |
|
break; |
|
case XFS_REFCOUNT_ALLOC_COW: |
|
*new_fsb = startblock + blockcount; |
|
*new_len = 0; |
|
error = __xfs_refcount_cow_alloc(rcur, bno, blockcount); |
|
break; |
|
case XFS_REFCOUNT_FREE_COW: |
|
*new_fsb = startblock + blockcount; |
|
*new_len = 0; |
|
error = __xfs_refcount_cow_free(rcur, bno, blockcount); |
|
break; |
|
default: |
|
ASSERT(0); |
|
error = -EFSCORRUPTED; |
|
} |
|
if (!error && *new_len > 0) |
|
trace_xfs_refcount_finish_one_leftover(mp, agno, type, |
|
bno, blockcount, new_agbno, *new_len); |
|
return error; |
|
} |
|
|
|
/* |
|
* Record a refcount intent for later processing. |
|
*/ |
|
static void |
|
__xfs_refcount_add( |
|
struct xfs_trans *tp, |
|
enum xfs_refcount_intent_type type, |
|
xfs_fsblock_t startblock, |
|
xfs_extlen_t blockcount) |
|
{ |
|
struct xfs_refcount_intent *ri; |
|
|
|
trace_xfs_refcount_defer(tp->t_mountp, |
|
XFS_FSB_TO_AGNO(tp->t_mountp, startblock), |
|
type, XFS_FSB_TO_AGBNO(tp->t_mountp, startblock), |
|
blockcount); |
|
|
|
ri = kmem_alloc(sizeof(struct xfs_refcount_intent), |
|
KM_NOFS); |
|
INIT_LIST_HEAD(&ri->ri_list); |
|
ri->ri_type = type; |
|
ri->ri_startblock = startblock; |
|
ri->ri_blockcount = blockcount; |
|
|
|
xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_REFCOUNT, &ri->ri_list); |
|
} |
|
|
|
/* |
|
* Increase the reference count of the blocks backing a file's extent. |
|
*/ |
|
void |
|
xfs_refcount_increase_extent( |
|
struct xfs_trans *tp, |
|
struct xfs_bmbt_irec *PREV) |
|
{ |
|
if (!xfs_sb_version_hasreflink(&tp->t_mountp->m_sb)) |
|
return; |
|
|
|
__xfs_refcount_add(tp, XFS_REFCOUNT_INCREASE, PREV->br_startblock, |
|
PREV->br_blockcount); |
|
} |
|
|
|
/* |
|
* Decrease the reference count of the blocks backing a file's extent. |
|
*/ |
|
void |
|
xfs_refcount_decrease_extent( |
|
struct xfs_trans *tp, |
|
struct xfs_bmbt_irec *PREV) |
|
{ |
|
if (!xfs_sb_version_hasreflink(&tp->t_mountp->m_sb)) |
|
return; |
|
|
|
__xfs_refcount_add(tp, XFS_REFCOUNT_DECREASE, PREV->br_startblock, |
|
PREV->br_blockcount); |
|
} |
|
|
|
/* |
|
* Given an AG extent, find the lowest-numbered run of shared blocks |
|
* within that range and return the range in fbno/flen. If |
|
* find_end_of_shared is set, return the longest contiguous extent of |
|
* shared blocks; if not, just return the first extent we find. If no |
|
* shared blocks are found, fbno and flen will be set to NULLAGBLOCK |
|
* and 0, respectively. |
|
*/ |
|
int |
|
xfs_refcount_find_shared( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen, |
|
xfs_agblock_t *fbno, |
|
xfs_extlen_t *flen, |
|
bool find_end_of_shared) |
|
{ |
|
struct xfs_refcount_irec tmp; |
|
int i; |
|
int have; |
|
int error; |
|
|
|
trace_xfs_refcount_find_shared(cur->bc_mp, cur->bc_ag.agno, |
|
agbno, aglen); |
|
|
|
/* By default, skip the whole range */ |
|
*fbno = NULLAGBLOCK; |
|
*flen = 0; |
|
|
|
/* Try to find a refcount extent that crosses the start */ |
|
error = xfs_refcount_lookup_le(cur, agbno, &have); |
|
if (error) |
|
goto out_error; |
|
if (!have) { |
|
/* No left extent, look at the next one */ |
|
error = xfs_btree_increment(cur, 0, &have); |
|
if (error) |
|
goto out_error; |
|
if (!have) |
|
goto done; |
|
} |
|
error = xfs_refcount_get_rec(cur, &tmp, &i); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
/* If the extent ends before the start, look at the next one */ |
|
if (tmp.rc_startblock + tmp.rc_blockcount <= agbno) { |
|
error = xfs_btree_increment(cur, 0, &have); |
|
if (error) |
|
goto out_error; |
|
if (!have) |
|
goto done; |
|
error = xfs_refcount_get_rec(cur, &tmp, &i); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
} |
|
|
|
/* If the extent starts after the range we want, bail out */ |
|
if (tmp.rc_startblock >= agbno + aglen) |
|
goto done; |
|
|
|
/* We found the start of a shared extent! */ |
|
if (tmp.rc_startblock < agbno) { |
|
tmp.rc_blockcount -= (agbno - tmp.rc_startblock); |
|
tmp.rc_startblock = agbno; |
|
} |
|
|
|
*fbno = tmp.rc_startblock; |
|
*flen = min(tmp.rc_blockcount, agbno + aglen - *fbno); |
|
if (!find_end_of_shared) |
|
goto done; |
|
|
|
/* Otherwise, find the end of this shared extent */ |
|
while (*fbno + *flen < agbno + aglen) { |
|
error = xfs_btree_increment(cur, 0, &have); |
|
if (error) |
|
goto out_error; |
|
if (!have) |
|
break; |
|
error = xfs_refcount_get_rec(cur, &tmp, &i); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
if (tmp.rc_startblock >= agbno + aglen || |
|
tmp.rc_startblock != *fbno + *flen) |
|
break; |
|
*flen = min(*flen + tmp.rc_blockcount, agbno + aglen - *fbno); |
|
} |
|
|
|
done: |
|
trace_xfs_refcount_find_shared_result(cur->bc_mp, |
|
cur->bc_ag.agno, *fbno, *flen); |
|
|
|
out_error: |
|
if (error) |
|
trace_xfs_refcount_find_shared_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Recovering CoW Blocks After a Crash |
|
* |
|
* Due to the way that the copy on write mechanism works, there's a window of |
|
* opportunity in which we can lose track of allocated blocks during a crash. |
|
* Because CoW uses delayed allocation in the in-core CoW fork, writeback |
|
* causes blocks to be allocated and stored in the CoW fork. The blocks are |
|
* no longer in the free space btree but are not otherwise recorded anywhere |
|
* until the write completes and the blocks are mapped into the file. A crash |
|
* in between allocation and remapping results in the replacement blocks being |
|
* lost. This situation is exacerbated by the CoW extent size hint because |
|
* allocations can hang around for long time. |
|
* |
|
* However, there is a place where we can record these allocations before they |
|
* become mappings -- the reference count btree. The btree does not record |
|
* extents with refcount == 1, so we can record allocations with a refcount of |
|
* 1. Blocks being used for CoW writeout cannot be shared, so there should be |
|
* no conflict with shared block records. These mappings should be created |
|
* when we allocate blocks to the CoW fork and deleted when they're removed |
|
* from the CoW fork. |
|
* |
|
* Minor nit: records for in-progress CoW allocations and records for shared |
|
* extents must never be merged, to preserve the property that (except for CoW |
|
* allocations) there are no refcount btree entries with refcount == 1. The |
|
* only time this could potentially happen is when unsharing a block that's |
|
* adjacent to CoW allocations, so we must be careful to avoid this. |
|
* |
|
* At mount time we recover lost CoW allocations by searching the refcount |
|
* btree for these refcount == 1 mappings. These represent CoW allocations |
|
* that were in progress at the time the filesystem went down, so we can free |
|
* them to get the space back. |
|
* |
|
* This mechanism is superior to creating EFIs for unmapped CoW extents for |
|
* several reasons -- first, EFIs pin the tail of the log and would have to be |
|
* periodically relogged to avoid filling up the log. Second, CoW completions |
|
* will have to file an EFD and create new EFIs for whatever remains in the |
|
* CoW fork; this partially takes care of (1) but extent-size reservations |
|
* will have to periodically relog even if there's no writeout in progress. |
|
* This can happen if the CoW extent size hint is set, which you really want. |
|
* Third, EFIs cannot currently be automatically relogged into newer |
|
* transactions to advance the log tail. Fourth, stuffing the log full of |
|
* EFIs places an upper bound on the number of CoW allocations that can be |
|
* held filesystem-wide at any given time. Recording them in the refcount |
|
* btree doesn't require us to maintain any state in memory and doesn't pin |
|
* the log. |
|
*/ |
|
/* |
|
* Adjust the refcounts of CoW allocations. These allocations are "magic" |
|
* in that they're not referenced anywhere else in the filesystem, so we |
|
* stash them in the refcount btree with a refcount of 1 until either file |
|
* remapping (or CoW cancellation) happens. |
|
*/ |
|
STATIC int |
|
xfs_refcount_adjust_cow_extents( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen, |
|
enum xfs_refc_adjust_op adj) |
|
{ |
|
struct xfs_refcount_irec ext, tmp; |
|
int error; |
|
int found_rec, found_tmp; |
|
|
|
if (aglen == 0) |
|
return 0; |
|
|
|
/* Find any overlapping refcount records */ |
|
error = xfs_refcount_lookup_ge(cur, agbno, &found_rec); |
|
if (error) |
|
goto out_error; |
|
error = xfs_refcount_get_rec(cur, &ext, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (!found_rec) { |
|
ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks + |
|
XFS_REFC_COW_START; |
|
ext.rc_blockcount = 0; |
|
ext.rc_refcount = 0; |
|
} |
|
|
|
switch (adj) { |
|
case XFS_REFCOUNT_ADJUST_COW_ALLOC: |
|
/* Adding a CoW reservation, there should be nothing here. */ |
|
if (XFS_IS_CORRUPT(cur->bc_mp, |
|
agbno + aglen > ext.rc_startblock)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
tmp.rc_startblock = agbno; |
|
tmp.rc_blockcount = aglen; |
|
tmp.rc_refcount = 1; |
|
trace_xfs_refcount_modify_extent(cur->bc_mp, |
|
cur->bc_ag.agno, &tmp); |
|
|
|
error = xfs_refcount_insert(cur, &tmp, |
|
&found_tmp); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_tmp != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
break; |
|
case XFS_REFCOUNT_ADJUST_COW_FREE: |
|
/* Removing a CoW reservation, there should be one extent. */ |
|
if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_startblock != agbno)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_blockcount != aglen)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_refcount != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
|
|
ext.rc_refcount = 0; |
|
trace_xfs_refcount_modify_extent(cur->bc_mp, |
|
cur->bc_ag.agno, &ext); |
|
error = xfs_refcount_delete(cur, &found_rec); |
|
if (error) |
|
goto out_error; |
|
if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) { |
|
error = -EFSCORRUPTED; |
|
goto out_error; |
|
} |
|
break; |
|
default: |
|
ASSERT(0); |
|
} |
|
|
|
return error; |
|
out_error: |
|
trace_xfs_refcount_modify_extent_error(cur->bc_mp, |
|
cur->bc_ag.agno, error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Add or remove refcount btree entries for CoW reservations. |
|
*/ |
|
STATIC int |
|
xfs_refcount_adjust_cow( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen, |
|
enum xfs_refc_adjust_op adj) |
|
{ |
|
bool shape_changed; |
|
int error; |
|
|
|
agbno += XFS_REFC_COW_START; |
|
|
|
/* |
|
* Ensure that no rcextents cross the boundary of the adjustment range. |
|
*/ |
|
error = xfs_refcount_split_extent(cur, agbno, &shape_changed); |
|
if (error) |
|
goto out_error; |
|
|
|
error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); |
|
if (error) |
|
goto out_error; |
|
|
|
/* |
|
* Try to merge with the left or right extents of the range. |
|
*/ |
|
error = xfs_refcount_merge_extents(cur, &agbno, &aglen, adj, |
|
XFS_FIND_RCEXT_COW, &shape_changed); |
|
if (error) |
|
goto out_error; |
|
|
|
/* Now that we've taken care of the ends, adjust the middle extents */ |
|
error = xfs_refcount_adjust_cow_extents(cur, agbno, aglen, adj); |
|
if (error) |
|
goto out_error; |
|
|
|
return 0; |
|
|
|
out_error: |
|
trace_xfs_refcount_adjust_cow_error(cur->bc_mp, cur->bc_ag.agno, |
|
error, _RET_IP_); |
|
return error; |
|
} |
|
|
|
/* |
|
* Record a CoW allocation in the refcount btree. |
|
*/ |
|
STATIC int |
|
__xfs_refcount_cow_alloc( |
|
struct xfs_btree_cur *rcur, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen) |
|
{ |
|
trace_xfs_refcount_cow_increase(rcur->bc_mp, rcur->bc_ag.agno, |
|
agbno, aglen); |
|
|
|
/* Add refcount btree reservation */ |
|
return xfs_refcount_adjust_cow(rcur, agbno, aglen, |
|
XFS_REFCOUNT_ADJUST_COW_ALLOC); |
|
} |
|
|
|
/* |
|
* Remove a CoW allocation from the refcount btree. |
|
*/ |
|
STATIC int |
|
__xfs_refcount_cow_free( |
|
struct xfs_btree_cur *rcur, |
|
xfs_agblock_t agbno, |
|
xfs_extlen_t aglen) |
|
{ |
|
trace_xfs_refcount_cow_decrease(rcur->bc_mp, rcur->bc_ag.agno, |
|
agbno, aglen); |
|
|
|
/* Remove refcount btree reservation */ |
|
return xfs_refcount_adjust_cow(rcur, agbno, aglen, |
|
XFS_REFCOUNT_ADJUST_COW_FREE); |
|
} |
|
|
|
/* Record a CoW staging extent in the refcount btree. */ |
|
void |
|
xfs_refcount_alloc_cow_extent( |
|
struct xfs_trans *tp, |
|
xfs_fsblock_t fsb, |
|
xfs_extlen_t len) |
|
{ |
|
struct xfs_mount *mp = tp->t_mountp; |
|
|
|
if (!xfs_sb_version_hasreflink(&mp->m_sb)) |
|
return; |
|
|
|
__xfs_refcount_add(tp, XFS_REFCOUNT_ALLOC_COW, fsb, len); |
|
|
|
/* Add rmap entry */ |
|
xfs_rmap_alloc_extent(tp, XFS_FSB_TO_AGNO(mp, fsb), |
|
XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW); |
|
} |
|
|
|
/* Forget a CoW staging event in the refcount btree. */ |
|
void |
|
xfs_refcount_free_cow_extent( |
|
struct xfs_trans *tp, |
|
xfs_fsblock_t fsb, |
|
xfs_extlen_t len) |
|
{ |
|
struct xfs_mount *mp = tp->t_mountp; |
|
|
|
if (!xfs_sb_version_hasreflink(&mp->m_sb)) |
|
return; |
|
|
|
/* Remove rmap entry */ |
|
xfs_rmap_free_extent(tp, XFS_FSB_TO_AGNO(mp, fsb), |
|
XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW); |
|
__xfs_refcount_add(tp, XFS_REFCOUNT_FREE_COW, fsb, len); |
|
} |
|
|
|
struct xfs_refcount_recovery { |
|
struct list_head rr_list; |
|
struct xfs_refcount_irec rr_rrec; |
|
}; |
|
|
|
/* Stuff an extent on the recovery list. */ |
|
STATIC int |
|
xfs_refcount_recover_extent( |
|
struct xfs_btree_cur *cur, |
|
union xfs_btree_rec *rec, |
|
void *priv) |
|
{ |
|
struct list_head *debris = priv; |
|
struct xfs_refcount_recovery *rr; |
|
|
|
if (XFS_IS_CORRUPT(cur->bc_mp, |
|
be32_to_cpu(rec->refc.rc_refcount) != 1)) |
|
return -EFSCORRUPTED; |
|
|
|
rr = kmem_alloc(sizeof(struct xfs_refcount_recovery), 0); |
|
xfs_refcount_btrec_to_irec(rec, &rr->rr_rrec); |
|
list_add_tail(&rr->rr_list, debris); |
|
|
|
return 0; |
|
} |
|
|
|
/* Find and remove leftover CoW reservations. */ |
|
int |
|
xfs_refcount_recover_cow_leftovers( |
|
struct xfs_mount *mp, |
|
xfs_agnumber_t agno) |
|
{ |
|
struct xfs_trans *tp; |
|
struct xfs_btree_cur *cur; |
|
struct xfs_buf *agbp; |
|
struct xfs_refcount_recovery *rr, *n; |
|
struct list_head debris; |
|
union xfs_btree_irec low; |
|
union xfs_btree_irec high; |
|
xfs_fsblock_t fsb; |
|
xfs_agblock_t agbno; |
|
int error; |
|
|
|
if (mp->m_sb.sb_agblocks >= XFS_REFC_COW_START) |
|
return -EOPNOTSUPP; |
|
|
|
INIT_LIST_HEAD(&debris); |
|
|
|
/* |
|
* In this first part, we use an empty transaction to gather up |
|
* all the leftover CoW extents so that we can subsequently |
|
* delete them. The empty transaction is used to avoid |
|
* a buffer lock deadlock if there happens to be a loop in the |
|
* refcountbt because we're allowed to re-grab a buffer that is |
|
* already attached to our transaction. When we're done |
|
* recording the CoW debris we cancel the (empty) transaction |
|
* and everything goes away cleanly. |
|
*/ |
|
error = xfs_trans_alloc_empty(mp, &tp); |
|
if (error) |
|
return error; |
|
|
|
error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); |
|
if (error) |
|
goto out_trans; |
|
cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno); |
|
|
|
/* Find all the leftover CoW staging extents. */ |
|
memset(&low, 0, sizeof(low)); |
|
memset(&high, 0, sizeof(high)); |
|
low.rc.rc_startblock = XFS_REFC_COW_START; |
|
high.rc.rc_startblock = -1U; |
|
error = xfs_btree_query_range(cur, &low, &high, |
|
xfs_refcount_recover_extent, &debris); |
|
xfs_btree_del_cursor(cur, error); |
|
xfs_trans_brelse(tp, agbp); |
|
xfs_trans_cancel(tp); |
|
if (error) |
|
goto out_free; |
|
|
|
/* Now iterate the list to free the leftovers */ |
|
list_for_each_entry_safe(rr, n, &debris, rr_list) { |
|
/* Set up transaction. */ |
|
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); |
|
if (error) |
|
goto out_free; |
|
|
|
trace_xfs_refcount_recover_extent(mp, agno, &rr->rr_rrec); |
|
|
|
/* Free the orphan record */ |
|
agbno = rr->rr_rrec.rc_startblock - XFS_REFC_COW_START; |
|
fsb = XFS_AGB_TO_FSB(mp, agno, agbno); |
|
xfs_refcount_free_cow_extent(tp, fsb, |
|
rr->rr_rrec.rc_blockcount); |
|
|
|
/* Free the block. */ |
|
xfs_bmap_add_free(tp, fsb, rr->rr_rrec.rc_blockcount, NULL); |
|
|
|
error = xfs_trans_commit(tp); |
|
if (error) |
|
goto out_free; |
|
|
|
list_del(&rr->rr_list); |
|
kmem_free(rr); |
|
} |
|
|
|
return error; |
|
out_trans: |
|
xfs_trans_cancel(tp); |
|
out_free: |
|
/* Free the leftover list */ |
|
list_for_each_entry_safe(rr, n, &debris, rr_list) { |
|
list_del(&rr->rr_list); |
|
kmem_free(rr); |
|
} |
|
return error; |
|
} |
|
|
|
/* Is there a record covering a given extent? */ |
|
int |
|
xfs_refcount_has_record( |
|
struct xfs_btree_cur *cur, |
|
xfs_agblock_t bno, |
|
xfs_extlen_t len, |
|
bool *exists) |
|
{ |
|
union xfs_btree_irec low; |
|
union xfs_btree_irec high; |
|
|
|
memset(&low, 0, sizeof(low)); |
|
low.rc.rc_startblock = bno; |
|
memset(&high, 0xFF, sizeof(high)); |
|
high.rc.rc_startblock = bno + len - 1; |
|
|
|
return xfs_btree_has_record(cur, &low, &high, exists); |
|
}
|
|
|