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xfs: sanity check ag header values in xrep_calc_ag_resblks

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Check the values we read in from the AG headers when calculating the
block reservations for a repair transaction.  If they're obviously
wrong, substitute worst case assumptions (rather than ENOSPC on a bogus
reservation request).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
This commit is contained in:
Darrick J. Wong 2018-08-10 17:55:57 -07:00
parent 00d22a1c36
commit 1fc25f51d7
1 changed files with 27 additions and 19 deletions
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46
fs/xfs/scrub/repair.c
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@ -195,8 +195,8 @@ xrep_calc_ag_resblks(
struct xfs_scrub_metadata *sm = sc->sm;
struct xfs_perag *pag;
struct xfs_buf *bp;
xfs_agino_t icount = 0;
xfs_extlen_t aglen = 0;
xfs_agino_t icount = NULLAGINO;
xfs_extlen_t aglen = NULLAGBLOCK;
xfs_extlen_t usedlen;
xfs_extlen_t freelen;
xfs_extlen_t bnobt_sz;
@ -208,20 +208,14 @@ xrep_calc_ag_resblks(
if (!(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
return 0;
/* Use in-core counters if possible. */
pag = xfs_perag_get(mp, sm->sm_agno);
if (pag->pagi_init)
if (pag->pagi_init) {
/* Use in-core icount if possible. */
icount = pag->pagi_count;
/*
* Otherwise try to get the actual counters from disk; if not, make
* some worst case assumptions.
*/
if (icount == 0) {
} else {
/* Try to get the actual counters from disk. */
error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp);
if (error) {
icount = mp->m_sb.sb_agblocks / mp->m_sb.sb_inopblock;
} else {
if (!error) {
icount = pag->pagi_count;
xfs_buf_relse(bp);
}
@ -229,18 +223,32 @@ xrep_calc_ag_resblks(
/* Now grab the block counters from the AGF. */
error = xfs_alloc_read_agf(mp, NULL, sm->sm_agno, 0, &bp);
if (error) {
aglen = mp->m_sb.sb_agblocks;
freelen = aglen;
usedlen = aglen;
} else {
if (!error) {
aglen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_length);
freelen = pag->pagf_freeblks;
freelen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_freeblks);
usedlen = aglen - freelen;
xfs_buf_relse(bp);
}
xfs_perag_put(pag);
/* If the icount is impossible, make some worst-case assumptions. */
if (icount == NULLAGINO ||
!xfs_verify_agino(mp, sm->sm_agno, icount)) {
xfs_agino_t first, last;
xfs_agino_range(mp, sm->sm_agno, &first, &last);
icount = last - first + 1;
}
/* If the block counts are impossible, make worst-case assumptions. */
if (aglen == NULLAGBLOCK ||
aglen != xfs_ag_block_count(mp, sm->sm_agno) ||
freelen >= aglen) {
aglen = xfs_ag_block_count(mp, sm->sm_agno);
freelen = aglen;
usedlen = aglen;
}
trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen,
freelen, usedlen);