Implement the data plane of reading data from data blobs over fscache
for inline layout.
For the heading non-inline part, the data plane for non-inline layout is
reused, while only the tail packing part needs special handling.
Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
---
fs/erofs/fscache.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index b799b0fe1b67..08849c15500f 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -84,6 +84,33 @@ static int erofs_fscache_meta_readpage(struct file *data, struct page *page)
return ret;
}
+static int erofs_fscache_readpage_inline(struct folio *folio,
+ struct erofs_map_blocks *map)
+{
+ struct super_block *sb = folio_mapping(folio)->host->i_sb;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ erofs_blk_t blknr;
+ size_t offset, len;
+ void *src, *dst;
+
+ /* For tail packing layout, the offset may be non-zero. */
+ offset = erofs_blkoff(map->m_pa);
+ blknr = erofs_blknr(map->m_pa);
+ len = map->m_llen;
+
+ src = erofs_read_metabuf(&buf, sb, blknr, EROFS_KMAP);
+ if (IS_ERR(src))
+ return PTR_ERR(src);
+
+ dst = kmap_local_folio(folio, 0);
+ memcpy(dst, src + offset, len);
+ memset(dst + len, 0, PAGE_SIZE - len);
+ kunmap_local(dst);
+
+ erofs_put_metabuf(&buf);
+ return 0;
+}
+
static int erofs_fscache_readpage(struct file *file, struct page *page)
{
struct folio *folio = page_folio(page);
@@ -109,6 +136,11 @@ static int erofs_fscache_readpage(struct file *file, struct page *page)
goto out_uptodate;
}
+ if (map.m_flags & EROFS_MAP_META) {
+ ret = erofs_fscache_readpage_inline(folio, &map);
+ goto out_uptodate;
+ }
+
mdev = (struct erofs_map_dev) {
.m_deviceid = map.m_deviceid,
.m_pa = map.m_pa,
--
2.27.0
