iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

btrfs: raid56: introduce btrfs_raid_bio::bio_sectors

Browse Source 
This new member is going to fully replace bio_pages in the future, but
for now let's keep them co-exist, until the full switch is done.

Currently cache_rbio_pages() and index_rbio_pages() will also populate
the new array.

And cache_rbio_pages() need to record which sectors are uptodate, so we
also need to introduce sector_ptr::uptodate bit.

To avoid extra memory usage, we let the new @uptodate bit to share bits
with @pgoff.  Now pgoff only has at most 31 bits, which is already more
than enough, as even for 256K page size, we only need 18 bits.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2022-04-01 19:23:20 +08:00 committed by David Sterba
parent eb3570607c
commit 00425dd976
1 changed files with 55 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
fs/btrfs/raid56.c
View File

@ -59,7 +59,8 @@ struct btrfs_stripe_hash_table {
*/
struct sector_ptr {
struct page *page;
unsigned int pgoff;
unsigned int pgoff:24;
unsigned int uptodate:8;
};
enum btrfs_rbio_ops {
@ -174,6 +175,9 @@ struct btrfs_raid_bio {
*/
struct page **stripe_pages;
/* Pointers to the sectors in the bio_list, for faster lookup */
struct sector_ptr *bio_sectors;
/*
* pointers to the pages in the bio_list. Stored
* here for faster lookup
@ -284,6 +288,24 @@ static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
copy_highpage(rbio->stripe_pages[i], rbio->bio_pages[i]);
SetPageUptodate(rbio->stripe_pages[i]);
}
/*
* This work is duplicated with the above loop, will be removed when
* the switch is done.
*/
for (i = 0; i < rbio->nr_sectors; i++) {
/* Some range not covered by bio (partial write), skip it */
if (!rbio->bio_sectors[i].page)
continue;
ASSERT(rbio->stripe_sectors[i].page);
memcpy_page(rbio->stripe_sectors[i].page,
rbio->stripe_sectors[i].pgoff,
rbio->bio_sectors[i].page,
rbio->bio_sectors[i].pgoff,
rbio->bioc->fs_info->sectorsize);
rbio->stripe_sectors[i].uptodate = 1;
}
set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
}
@ -1012,7 +1034,7 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
rbio = kzalloc(sizeof(*rbio) +
sizeof(*rbio->stripe_pages) * num_pages +
sizeof(*rbio->bio_pages) * num_pages +
sizeof(*rbio->bio_sectors) * num_sectors +
sizeof(*rbio->stripe_sectors) * num_sectors +
sizeof(*rbio->finish_pointers) * real_stripes +
sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_nsectors) +
@ -1050,6 +1072,7 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
} while (0)
CONSUME_ALLOC(rbio->stripe_pages, num_pages);
CONSUME_ALLOC(rbio->bio_pages, num_pages);
CONSUME_ALLOC(rbio->bio_sectors, num_sectors);
CONSUME_ALLOC(rbio->stripe_sectors, num_sectors);
CONSUME_ALLOC(rbio->finish_pointers, real_stripes);
CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_nsectors));
@ -1166,6 +1189,32 @@ static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio)
}
}
static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
struct bio_vec bvec;
struct bvec_iter iter;
u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
rbio->bioc->raid_map[0];
if (bio_flagged(bio, BIO_CLONED))
bio->bi_iter = btrfs_bio(bio)->iter;
bio_for_each_segment(bvec, bio, iter) {
u32 bvec_offset;
for (bvec_offset = 0; bvec_offset < bvec.bv_len;
bvec_offset += sectorsize, offset += sectorsize) {
int index = offset / sectorsize;
struct sector_ptr *sector = &rbio->bio_sectors[index];
sector->page = bvec.bv_page;
sector->pgoff = bvec.bv_offset + bvec_offset;
ASSERT(sector->pgoff < PAGE_SIZE);
}
}
}
/*
* helper function to walk our bio list and populate the bio_pages array with
* the result. This seems expensive, but it is faster than constantly
@ -1196,6 +1245,10 @@ static void index_rbio_pages(struct btrfs_raid_bio *rbio)
i++;
}
}
/* This loop will replace above loop when the full switch is done */
bio_list_for_each(bio, &rbio->bio_list)
index_one_bio(rbio, bio);
spin_unlock_irq(&rbio->bio_list_lock);
}