Hi Christian,
On 2025/7/3 20:23, Christian Brauner wrote:
From: Hongzhen Luo <hongz...@linux.alibaba.com>
This modifies relevant functions to apply the page cache
share feature.
Signed-off-by: Hongzhen Luo <hongz...@linux.alibaba.com>
Link:
https://lore.kernel.org/20240902110620.2202586-4-hongz...@linux.alibaba.com
Signed-off-by: Christian Brauner <brau...@kernel.org>
---
fs/erofs/data.c | 33 +++++++++++++++++++++++++++++++++
fs/erofs/inode.c | 15 ++++++++++++++-
fs/erofs/super.c | 29 +++++++++++++++++++++++++++++
fs/erofs/zdata.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 108 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 6a329c329f43..fb54162f4c54 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -351,12 +351,45 @@ int erofs_fiemap(struct inode *inode, struct
fiemap_extent_info *fieinfo,
*/
static int erofs_read_folio(struct file *file, struct folio *folio)
{
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ struct erofs_inode *vi = NULL;
+ int ret;
+
+ if (file && file->private_data) {
+ vi = file->private_data;
+ if (vi->ano_inode == file_inode(file))
+ folio->mapping->host = &vi->vfs_inode;
This is one of the parts I asked Hongzhen to refactor
because it simply doesn't work.
The background is that:
- since the folio is from the anon_inode mapping now,
so .iomap_begin() will use the anon inode rather
than a real inode in a sb, which causes iomap
don't find the real data source to read;
- Hongzhen just switch `folio->mapping->host` but it's
just broken. Also `file` here can be NULL if the
request is a kernel-internal request, so we'd better
not rely on `file` argument.
- My suggestion was that maintain a inode list so that
erofs_iomap_begin() can find any valid sb inode to
find data source instead.
+ else
+ vi = NULL;
+ }
+ ret = iomap_read_folio(folio, &erofs_iomap_ops);
+ if (vi)
+ folio->mapping->host = file_inode(file);
here.
+ return ret;
+#else
return iomap_read_folio(folio, &erofs_iomap_ops);
+#endif
}
static void erofs_readahead(struct readahead_control *rac)
{
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
Also the #ifdef are too ugly from the upstream code cycle.
Thanks,
Gao Xiang
