erofs: implement fscache-based metadata read

Implement the data plane of reading metadata from primary data blob
over fscache.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220425122143.56815-18-jefflexu@linux.alibaba.com
Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Jeffle Xu 2022-04-25 20:21:39 +08:00 коммит произвёл Gao Xiang
Родитель 955b478e1b
Коммит 5375e7c8b0
2 изменённых файлов: 40 добавлений и 4 удалений

Просмотреть файл

@ -6,6 +6,7 @@
*/ */
#include "internal.h" #include "internal.h"
#include <linux/prefetch.h> #include <linux/prefetch.h>
#include <linux/sched/mm.h>
#include <linux/dax.h> #include <linux/dax.h>
#include <trace/events/erofs.h> #include <trace/events/erofs.h>
@ -35,14 +36,20 @@ void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
erofs_off_t offset = blknr_to_addr(blkaddr); erofs_off_t offset = blknr_to_addr(blkaddr);
pgoff_t index = offset >> PAGE_SHIFT; pgoff_t index = offset >> PAGE_SHIFT;
struct page *page = buf->page; struct page *page = buf->page;
struct folio *folio;
unsigned int nofs_flag;
if (!page || page->index != index) { if (!page || page->index != index) {
erofs_put_metabuf(buf); erofs_put_metabuf(buf);
page = read_cache_page_gfp(mapping, index,
mapping_gfp_constraint(mapping, ~__GFP_FS)); nofs_flag = memalloc_nofs_save();
if (IS_ERR(page)) folio = read_cache_folio(mapping, index, NULL, NULL);
return page; memalloc_nofs_restore(nofs_flag);
if (IS_ERR(folio))
return folio;
/* should already be PageUptodate, no need to lock page */ /* should already be PageUptodate, no need to lock page */
page = folio_file_page(folio, index);
buf->page = page; buf->page = page;
} }
if (buf->kmap_type == EROFS_NO_KMAP) { if (buf->kmap_type == EROFS_NO_KMAP) {
@ -63,6 +70,10 @@ void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
erofs_blk_t blkaddr, enum erofs_kmap_type type) erofs_blk_t blkaddr, enum erofs_kmap_type type)
{ {
if (erofs_is_fscache_mode(sb))
return erofs_bread(buf, EROFS_SB(sb)->s_fscache->inode,
blkaddr, type);
return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type); return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type);
} }

Просмотреть файл

@ -59,7 +59,32 @@ out:
return ret; return ret;
} }
static int erofs_fscache_meta_readpage(struct file *data, struct page *page)
{
int ret;
struct folio *folio = page_folio(page);
struct super_block *sb = folio_mapping(folio)->host->i_sb;
struct erofs_map_dev mdev = {
.m_deviceid = 0,
.m_pa = folio_pos(folio),
};
ret = erofs_map_dev(sb, &mdev);
if (ret)
goto out;
ret = erofs_fscache_read_folios(mdev.m_fscache->cookie,
folio_mapping(folio), folio_pos(folio),
folio_size(folio), mdev.m_pa);
if (!ret)
folio_mark_uptodate(folio);
out:
folio_unlock(folio);
return ret;
}
static const struct address_space_operations erofs_fscache_meta_aops = { static const struct address_space_operations erofs_fscache_meta_aops = {
.readpage = erofs_fscache_meta_readpage,
}; };
int erofs_fscache_register_cookie(struct super_block *sb, int erofs_fscache_register_cookie(struct super_block *sb,