Commit 46900662 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: raid56: make finish_parity_scrub() subpage compatible 



The core is to convert direct page usage into sector_ptr usage, and
use memcpy() to replace copy_page().

For pointers usage, we need to convert it to kmap_local_page() +
sector->pgoff.

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3e77605d

fs/btrfs/raid56.c

+32 −24
Original line number Diff line number Diff line
@@ -2470,14 +2470,15 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, 
					 int need_check)

{

	struct btrfs_io_context *bioc = rbio->bioc;

	const u32 sectorsize = bioc->fs_info->sectorsize;

	void **pointers = rbio->finish_pointers;

	unsigned long *pbitmap = rbio->finish_pbitmap;

	int nr_data = rbio->nr_data;

	int stripe;

	int sectornr;

	bool has_qstripe;

	struct page *p_page = NULL;

	struct page *q_page = NULL;

	struct sector_ptr p_sector = { 0 };

	struct sector_ptr q_sector = { 0 };

	struct bio_list bio_list;

	struct bio *bio;

	int is_replace = 0;
@@ -2507,51 +2508,56 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, 
	if (!need_check)

		goto writeback;



	p_page = alloc_page(GFP_NOFS);

	if (!p_page)

	p_sector.page = alloc_page(GFP_NOFS);

	if (!p_sector.page)

		goto cleanup;

	SetPageUptodate(p_page);

	p_sector.pgoff = 0;

	p_sector.uptodate = 1;



	if (has_qstripe) {

		/* RAID6, allocate and map temp space for the Q stripe */

		q_page = alloc_page(GFP_NOFS);

		if (!q_page) {

			__free_page(p_page);

		q_sector.page = alloc_page(GFP_NOFS);

		if (!q_sector.page) {

			__free_page(p_sector.page);

			p_sector.page = NULL;

			goto cleanup;

		}

		SetPageUptodate(q_page);

		pointers[rbio->real_stripes - 1] = kmap_local_page(q_page);

		q_sector.pgoff = 0;

		q_sector.uptodate = 1;

		pointers[rbio->real_stripes - 1] = kmap_local_page(q_sector.page);

	}



	atomic_set(&rbio->error, 0);



	/* Map the parity stripe just once */

	pointers[nr_data] = kmap_local_page(p_page);

	pointers[nr_data] = kmap_local_page(p_sector.page);



	for_each_set_bit(sectornr, rbio->dbitmap, rbio->stripe_nsectors) {

		struct page *p;

		struct sector_ptr *sector;

		void *parity;



		/* first collect one page from each data stripe */

		for (stripe = 0; stripe < nr_data; stripe++) {

			p = page_in_rbio(rbio, stripe, sectornr, 0);

			pointers[stripe] = kmap_local_page(p);

			sector = sector_in_rbio(rbio, stripe, sectornr, 0);

			pointers[stripe] = kmap_local_page(sector->page) +

					   sector->pgoff;

		}



		if (has_qstripe) {

			/* RAID6, call the library function to fill in our P/Q */

			raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,

			raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,

						pointers);

		} else {

			/* raid5 */

			copy_page(pointers[nr_data], pointers[0]);

			run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);

			memcpy(pointers[nr_data], pointers[0], sectorsize);

			run_xor(pointers + 1, nr_data - 1, sectorsize);

		}



		/* Check scrubbing parity and repair it */

		p = rbio_stripe_page(rbio, rbio->scrubp, sectornr);

		parity = kmap_local_page(p);

		if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE))

			copy_page(parity, pointers[rbio->scrubp]);

		sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);

		parity = kmap_local_page(sector->page) + sector->pgoff;

		if (memcmp(parity, pointers[rbio->scrubp], sectorsize) != 0)

			memcpy(parity, pointers[rbio->scrubp], sectorsize);

		else

			/* Parity is right, needn't writeback */

			bitmap_clear(rbio->dbitmap, sectornr, 1);
@@ -2562,10 +2568,12 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, 
	}



	kunmap_local(pointers[nr_data]);

	__free_page(p_page);

	if (q_page) {

	__free_page(p_sector.page);

	p_sector.page = NULL;

	if (q_sector.page) {

		kunmap_local(pointers[rbio->real_stripes - 1]);

		__free_page(q_page);

		__free_page(q_sector.page);

		q_sector.page = NULL;

	}



writeback: