btrfs: prepare scrub to support bs > ps cases

This involves:

- Migrate scrub_stripe::pages[] to folios[]

- Use btrfs_alloc_folio_array() and folio_put() to alloc above array.

- Migrate scrub_stripe_get_kaddr() and scrub_stripe_get_paddr() to use
  folio interfaces

- Migrate raid56_parity_cache_data_pages() to
  raid56_parity_cache_data_folios()
  Since scrub is the only caller still using pages.

  This helper will copy the folio array contents into rbio::stripe_pages,
  with sector uptodate flags updated.

  And a new ASSERT() to make sure bs > ps cases will not hit this path.

Since most scrub code is based on kaddr/paddr, the migration itself is
pretty straightforward.

And since we're here, also move the loop to set the
stripe_sectors[].uptodate out of the copy loop.
As we always mark all the sectors as uptodate for the data stripe, it's
easier to do in one go, other than doing it inside the copy loop.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 29 insertions, 22 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index cef260ed854c..ce28dcb60f78 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -130,7 +130,7 @@ enum {
 	scrub_bitmap_nr_last,
 };
 
-#define SCRUB_STRIPE_PAGES		(BTRFS_STRIPE_LEN / PAGE_SIZE)
+#define SCRUB_STRIPE_MAX_FOLIOS		(BTRFS_STRIPE_LEN / PAGE_SIZE)
 
 /*
  * Represent one contiguous range with a length of BTRFS_STRIPE_LEN.
@@ -139,7 +139,7 @@ struct scrub_stripe {
 	struct scrub_ctx *sctx;
 	struct btrfs_block_group *bg;
 
-	struct page *pages[SCRUB_STRIPE_PAGES];
+	struct folio *folios[SCRUB_STRIPE_MAX_FOLIOS];
 	struct scrub_sector_verification *sectors;
 
 	struct btrfs_device *dev;
@@ -339,10 +339,10 @@ static void release_scrub_stripe(struct scrub_stripe *stripe)
 	if (!stripe)
 		return;
 
-	for (int i = 0; i < SCRUB_STRIPE_PAGES; i++) {
-		if (stripe->pages[i])
-			__free_page(stripe->pages[i]);
-		stripe->pages[i] = NULL;
+	for (int i = 0; i < SCRUB_STRIPE_MAX_FOLIOS; i++) {
+		if (stripe->folios[i])
+			folio_put(stripe->folios[i]);
+		stripe->folios[i] = NULL;
 	}
 	kfree(stripe->sectors);
 	kfree(stripe->csums);
@@ -355,6 +355,7 @@ static void release_scrub_stripe(struct scrub_stripe *stripe)
 static int init_scrub_stripe(struct btrfs_fs_info *fs_info,
 			     struct scrub_stripe *stripe)
 {
+	const u32 min_folio_shift = PAGE_SHIFT + fs_info->block_min_order;
 	int ret;
 
 	memset(stripe, 0, sizeof(*stripe));
@@ -367,7 +368,9 @@ static int init_scrub_stripe(struct btrfs_fs_info *fs_info,
 	atomic_set(&stripe->pending_io, 0);
 	spin_lock_init(&stripe->write_error_lock);
 
-	ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages, false);
+	ASSERT(BTRFS_STRIPE_LEN >> min_folio_shift <= SCRUB_STRIPE_MAX_FOLIOS);
+	ret = btrfs_alloc_folio_array(BTRFS_STRIPE_LEN >> min_folio_shift,
+				      fs_info->block_min_order, stripe->folios);
 	if (ret < 0)
 		goto error;
 
@@ -687,27 +690,30 @@ static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
 
 static void *scrub_stripe_get_kaddr(struct scrub_stripe *stripe, int sector_nr)
 {
-	u32 offset = (sector_nr << stripe->bg->fs_info->sectorsize_bits);
-	const struct page *page = stripe->pages[offset >> PAGE_SHIFT];
+	struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
+	const u32 min_folio_shift = PAGE_SHIFT + fs_info->block_min_order;
+	u32 offset = (sector_nr << fs_info->sectorsize_bits);
+	const struct folio *folio = stripe->folios[offset >> min_folio_shift];
 
-	/* stripe->pages[] is allocated by us and no highmem is allowed. */
-	ASSERT(page);
-	ASSERT(!PageHighMem(page));
-	return page_address(page) + offset_in_page(offset);
+	/* stripe->folios[] is allocated by us and no highmem is allowed. */
+	ASSERT(folio);
+	ASSERT(!folio_test_partial_kmap(folio));
+	return folio_address(folio) + offset_in_folio(folio, offset);
 }
 
 static phys_addr_t scrub_stripe_get_paddr(struct scrub_stripe *stripe, int sector_nr)
 {
 	struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
+	const u32 min_folio_shift = PAGE_SHIFT + fs_info->block_min_order;
 	u32 offset = (sector_nr << fs_info->sectorsize_bits);
-	const struct page *page = stripe->pages[offset >> PAGE_SHIFT];
+	const struct folio *folio = stripe->folios[offset >> min_folio_shift];
 
-	/* stripe->pages[] is allocated by us and no highmem is allowed. */
-	ASSERT(page);
-	ASSERT(!PageHighMem(page));
-	/* And the range must be contained inside the page. */
-	ASSERT(offset_in_page(offset) + fs_info->sectorsize <= PAGE_SIZE);
-	return page_to_phys(page) + offset_in_page(offset);
+	/* stripe->folios[] is allocated by us and no highmem is allowed. */
+	ASSERT(folio);
+	ASSERT(!folio_test_partial_kmap(folio));
+	/* And the range must be contained inside the folio. */
+	ASSERT(offset_in_folio(folio, offset) + fs_info->sectorsize <= folio_size(folio));
+	return page_to_phys(folio_page(folio, 0)) + offset_in_folio(folio, offset);
 }
 
 static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr)
@@ -1872,6 +1878,7 @@ static void scrub_submit_initial_read(struct scrub_ctx *sctx,
 {
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct btrfs_bio *bbio;
+	const u32 min_folio_shift = PAGE_SHIFT + fs_info->block_min_order;
 	unsigned int nr_sectors = stripe_length(stripe) >> fs_info->sectorsize_bits;
 	int mirror = stripe->mirror_num;
 
@@ -1884,7 +1891,7 @@ static void scrub_submit_initial_read(struct scrub_ctx *sctx,
 		return;
 	}
 
-	bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info,
+	bbio = btrfs_bio_alloc(BTRFS_STRIPE_LEN >> min_folio_shift, REQ_OP_READ, fs_info,
 			       scrub_read_endio, stripe);
 
 	bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT;
@@ -2215,7 +2222,7 @@ static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
 	for (int i = 0; i < data_stripes; i++) {
 		stripe = &sctx->raid56_data_stripes[i];
 
-		raid56_parity_cache_data_pages(rbio, stripe->pages,
+		raid56_parity_cache_data_folios(rbio, stripe->folios,
 				full_stripe_start + (i << BTRFS_STRIPE_LEN_SHIFT));
 	}
 	raid56_parity_submit_scrub_rbio(rbio);