On 08/11/2018 08:35 AM, Darrick J. Wong wrote:
From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
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
reservatoin request).
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/scrub/repair.c | 46 +++++++++++++++++++++++++++-------------------
1 file changed, 27 insertions(+), 19 deletions(-)
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 42d8c798ce7d..97c3077fb005 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -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);
Ok, makes sense
Reviewed-by: Allison Henderson <allison.henderson@xxxxxxxxxx>
