Implement the data plane of reading metadata from primary data blob
over fscache.
Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
---
fs/erofs/data.c | 20 ++++++++++++++++++--
fs/erofs/fscache.c | 38 ++++++++++++++++++++++++++++++++++++++
fs/erofs/internal.h | 9 +++++++++
3 files changed, 65 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 14b64d960541..cb8fe299ad67 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -31,15 +31,26 @@ void erofs_put_metabuf(struct erofs_buf *buf)
void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
- struct address_space *const mapping = inode->i_mapping;
erofs_off_t offset = blknr_to_addr(blkaddr);
pgoff_t index = offset >> PAGE_SHIFT;
struct page *page = buf->page;
if (!page || page->index != index) {
erofs_put_metabuf(buf);
- page = read_cache_page_gfp(mapping, index,
+ if (buf->sb) {
+ struct folio *folio;
+
+ folio = erofs_fscache_get_folio(buf->sb, index);
+ if (IS_ERR(folio))
+ page = ERR_CAST(folio);
+ else
+ page = folio_page(folio, 0);
+ } else {
+ struct address_space *const mapping = inode->i_mapping;
+
+ page = read_cache_page_gfp(mapping, index,
mapping_gfp_constraint(mapping, ~__GFP_FS));
+ }
if (IS_ERR(page))
return page;
/* should already be PageUptodate, no need to lock page */
@@ -63,6 +74,11 @@ void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
+ if (erofs_is_fscache_mode(sb)) {
+ buf->sb = sb;
+ return erofs_bread(buf, NULL, blkaddr, type);
+ }
+
return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type);
}
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index d38a6efc8e50..158cc273f8fb 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -34,9 +34,47 @@ static int erofs_fscache_read_folios(struct fscache_cookie *cookie,
return ret;
}
+static int erofs_fscache_meta_readpage(struct file *data, struct page *page)
+{
+ int ret;
+ struct super_block *sb = (struct super_block *)data;
+ struct folio *folio = page_folio(page);
+ 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_file_mapping(folio), folio_pos(folio),
+ folio_size(folio), mdev.m_pa);
+ if (ret)
+ goto out;
+
+ folio_mark_uptodate(folio);
+out:
+ folio_unlock(folio);
+ return ret;
+}
+
static const struct address_space_operations erofs_fscache_meta_aops = {
+ .readpage = erofs_fscache_meta_readpage,
};
+/*
+ * Get the page cache of data blob at the index offset.
+ * Return: up to date page on success, ERR_PTR() on failure.
+ */
+struct folio *erofs_fscache_get_folio(struct super_block *sb, pgoff_t index)
+{
+ struct erofs_fscache *ctx = EROFS_SB(sb)->s_fscache;
+
+ return read_mapping_folio(ctx->inode->i_mapping, index, (void *)sb);
+}
+
/*
* Create an fscache context for data blob.
* Return: 0 on success and allocated fscache context is assigned to @fscache,
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 90f7d6286a4f..e186051f0640 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -276,6 +276,7 @@ enum erofs_kmap_type {
};
struct erofs_buf {
+ struct super_block *sb;
struct page *page;
void *base;
enum erofs_kmap_type kmap_type;
@@ -639,6 +640,8 @@ int erofs_fscache_register_cookie(struct super_block *sb,
struct erofs_fscache **fscache,
char *name, bool need_inode);
void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache);
+
+struct folio *erofs_fscache_get_folio(struct super_block *sb, pgoff_t index);
#else
static inline int erofs_fscache_register_fs(struct super_block *sb) { return 0; }
static inline void erofs_fscache_unregister_fs(struct super_block *sb) {}
@@ -653,6 +656,12 @@ static inline int erofs_fscache_register_cookie(struct super_block *sb,
static inline void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
{
}
+
+static inline struct folio *erofs_fscache_get_folio(struct super_block *sb,
+ pgoff_t index)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
#endif
#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
--
2.27.0
--
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