@@ -176,8 +176,16 @@ static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
for (i = 0; i < rbio->nr_sectors; i++) {
/* Some range not covered by bio (partial write), skip it */
- if (!rbio->bio_sectors[i].page)
+ if (!rbio->bio_sectors[i].page) {
+ /*
+ * Even if the sector is not covered by bio, if it is
+ * a data sector it should still be uptodate as it is
+ * read from disk.
+ */
+ if (i < rbio->nr_data * rbio->stripe_nsectors)
+ ASSERT(rbio->stripe_sectors[i].uptodate);
continue;
+ }
ASSERT(rbio->stripe_sectors[i].page);
memcpy_page(rbio->stripe_sectors[i].page,
@@ -264,6 +272,21 @@ static void steal_rbio_page(struct btrfs_raid_bio *src,
dest->stripe_sectors[i].uptodate = true;
}
+static bool is_data_stripe_page(struct btrfs_raid_bio *rbio, int page_nr)
+{
+ const int sector_nr = (page_nr << PAGE_SHIFT) >>
+ rbio->bioc->fs_info->sectorsize_bits;
+
+ /*
+ * We have ensured PAGE_SIZE is aligned with sectorsize, thus
+ * we won't have a page which is half data half parity.
+ *
+ * Thus if the first sector of the page belongs to data stripes, then
+ * the full page belongs to data stripes.
+ */
+ return (sector_nr < rbio->nr_data * rbio->stripe_nsectors);
+}
+
/*
* Stealing an rbio means taking all the uptodate pages from the stripe array
* in the source rbio and putting them into the destination rbio.
@@ -274,16 +297,26 @@ static void steal_rbio_page(struct btrfs_raid_bio *src,
static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
{
int i;
- struct page *s;
if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
return;
for (i = 0; i < dest->nr_pages; i++) {
- s = src->stripe_pages[i];
- if (!s || !full_page_sectors_uptodate(src, i))
+ struct page *p = src->stripe_pages[i];
+
+ /*
+ * We don't need to steal P/Q pages as they will always be
+ * regenerated for RMW or full write anyway.
+ */
+ if (!is_data_stripe_page(src, i))
continue;
+ /*
+ * If @src already has RBIO_CACHE_READY_BIT, it should have
+ * all data stripe pages present and uptodate.
+ */
+ ASSERT(p);
+ ASSERT(full_page_sectors_uptodate(src, i));
steal_rbio_page(src, dest, i);
}
index_stripe_sectors(dest);
@@ -2003,22 +2036,21 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
/* xor in the rest */
run_xor(pointers, rbio->nr_data - 1, sectorsize);
}
- /* if we're doing this rebuild as part of an rmw, go through
- * and set all of our private rbio pages in the
- * failed stripes as uptodate. This way finish_rmw will
- * know they can be trusted. If this was a read reconstruction,
- * other endio functions will fiddle the uptodate bits
+
+ /*
+ * No matter if this is a RMW or recovery, we should have all
+ * failed sectors repaired, thus they are now uptodate.
+ * Especially if we determine to cache the rbio, we need to
+ * have at least all data sectors uptodate.
*/
- if (rbio->operation == BTRFS_RBIO_WRITE) {
- for (i = 0; i < rbio->stripe_nsectors; i++) {
- if (faila != -1) {
- sector = rbio_stripe_sector(rbio, faila, i);
- sector->uptodate = 1;
- }
- if (failb != -1) {
- sector = rbio_stripe_sector(rbio, failb, i);
- sector->uptodate = 1;
- }
+ for (i = 0; i < rbio->stripe_nsectors; i++) {
+ if (faila != -1) {
+ sector = rbio_stripe_sector(rbio, faila, i);
+ sector->uptodate = 1;
+ }
+ if (failb != -1) {
+ sector = rbio_stripe_sector(rbio, failb, i);
+ sector->uptodate = 1;
}
}
for (stripe = rbio->real_stripes - 1; stripe >= 0; stripe--)
For Btrfs RAID56, we have a caching system for btrfs raid bios (rbio). We call cache_rbio_pages() to mark a qualified rbio ready for cache. The timing happens at: - finish_rmw() At this timing, we have already read all necessary sectors, along with the rbio sectors, we have covered all data stripes. - __raid_recover_end_io() At this timing, we have rebuild the rbio, thus all data sectors involved (either from stripe or bio list) are uptodate now. Thus at the timing of cache_rbio_pages(), we should have all data sectors uptodate. This patch will make it explicit that all data sectors are uptodate at cache_rbio_pages() timing, mostly to prepare for the incoming verification at RMW time. This patch will add: - Extra ASSERT()s in cache_rbio_pages() This is to make sure all data sectors, which are not covered by bio, are already uptodate. - Extra ASSERT()s in steal_rbio() Since only cached rbio can be stolen, thus every data sector should already be uptodate in the source rbio. - Update __raid_recover_end_io() to update recovered sector->uptodate Previously __raid_recover_end_io() will only mark failed sectors uptodate if it's doing an RMW. But this can trigger new ASSERT()s, as for recovery case, a recovered failed sector will not be marked uptodate, and trigger ASSERT() in later cache_rbio_pages() call. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/raid56.c | 70 ++++++++++++++++++++++++++++++++++------------- 1 file changed, 51 insertions(+), 19 deletions(-)