Message ID | 20220406075612.60298-19-jefflexu@linux.alibaba.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | fscache,erofs: fscache-based on-demand read semantics | expand |
On Wed, Apr 06, 2022 at 03:56:10PM +0800, Jeffle Xu wrote: > 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@linux.alibaba.com> > --- > fs/erofs/fscache.c | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c > index 65de1c754e80..d32cb5840c6d 100644 > --- a/fs/erofs/fscache.c > +++ b/fs/erofs/fscache.c > @@ -60,6 +60,40 @@ 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 inode *inode = folio_file_mapping(folio)->host; > + struct super_block *sb = inode->i_sb; > + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; > + erofs_blk_t blknr; > + size_t offset, len; > + void *src, *dst; > + > + /* > + * For inline (tail packing) layout, the offset may be non-zero, which > + * can be calculated from corresponding physical address directly. > + */ > + 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); > + > + DBG_BUGON(folio_size(folio) != PAGE_SIZE); > + > + dst = kmap(folio_page(folio, 0)); kmap_local_folio? > + memcpy(dst, src + offset, len); > + memset(dst + len, 0, PAGE_SIZE - len); > + kunmap(folio_page(folio, 0)); > + > + erofs_put_metabuf(&buf); > + > + return 0; > +} > + > static int erofs_fscache_readpage(struct file *file, struct page *page) > { > struct folio *folio = page_folio(page); > @@ -85,6 +119,12 @@ static int erofs_fscache_readpage(struct file *file, struct page *page) > goto out_uptodate; > } > > + /* inline readpage */ I think the code below is self-explained. > + if (map.m_flags & EROFS_MAP_META) { > + ret = erofs_fscache_readpage_inline(folio, &map); > + goto out_uptodate; > + } > + > /* no-inline readpage */ Same here. Thanks, Gao Xiang > mdev = (struct erofs_map_dev) { > .m_deviceid = map.m_deviceid, > -- > 2.27.0 >
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 65de1c754e80..d32cb5840c6d 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -60,6 +60,40 @@ 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 inode *inode = folio_file_mapping(folio)->host; + struct super_block *sb = inode->i_sb; + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + erofs_blk_t blknr; + size_t offset, len; + void *src, *dst; + + /* + * For inline (tail packing) layout, the offset may be non-zero, which + * can be calculated from corresponding physical address directly. + */ + 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); + + DBG_BUGON(folio_size(folio) != PAGE_SIZE); + + dst = kmap(folio_page(folio, 0)); + memcpy(dst, src + offset, len); + memset(dst + len, 0, PAGE_SIZE - len); + kunmap(folio_page(folio, 0)); + + erofs_put_metabuf(&buf); + + return 0; +} + static int erofs_fscache_readpage(struct file *file, struct page *page) { struct folio *folio = page_folio(page); @@ -85,6 +119,12 @@ static int erofs_fscache_readpage(struct file *file, struct page *page) goto out_uptodate; } + /* inline readpage */ + if (map.m_flags & EROFS_MAP_META) { + ret = erofs_fscache_readpage_inline(folio, &map); + goto out_uptodate; + } + /* no-inline readpage */ mdev = (struct erofs_map_dev) { .m_deviceid = map.m_deviceid,
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@linux.alibaba.com> --- fs/erofs/fscache.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)