xfs/scrub/refcount.c

50  * We want to count the reverse mappings overlapping a refcount record
51  * (bno, len, refcount), allowing for the possibility that some of the
56  * 1. For all reverse mappings overlapping the refcount extent,
62  * refcount record we want to find $refcount owners and we've already
64  * need to find ($refcount - $seen) owners for every block in the
78  *    and that they all end at or beyond the end of the refcount extent.
80  * If the refcount is correct, all the check conditions in the algorithm
81  * should always hold true.  If not, the refcount is incorrect.
92 	/* refcount extent we're examining */
95 	xfs_nlink_t		refcount;
103  * towards refcount verification now, or if it's a fragment, in
127 	if (refchk->refcount == 1 && rec->rm_owner != XFS_RMAP_OWN_COW) {
134 		 * The rmap overlaps the refcount record, so we can confirm
135 		 * one refcount owner seen.
140 		 * This rmap covers only part of the refcount record, so
158  * a running tally of the refcount.  If this ever deviates from
159  * what we expect (which is the refcountbt's refcount minus the
176 	target_nr = refchk->refcount - refchk->seen;
181 	 * There are (refchk->rc.rc_refcount - refchk->nr refcount)
186 	 * refcount record's range.
216 	 * at or before the refcount extent.
254 		 * required refcount.  Something is wrong, so we're done.
264 	 * the end of the refcount extent.
269 	/* Actually record us having seen the remaining refcount. */
270 	refchk->seen = refchk->refcount;
283 /* Use the rmap entries covering this extent to verify the refcount. */
293 		.refcount		= irec->rc_refcount,
305 	/* Cross-reference with the rmapbt to confirm the refcount. */
346 	/* Previous refcount record. */
520 /* Scrub the refcount btree for some AG. */
538 	 * Check that all blocks between the last refcount > 1 record and the