[PATCH v2] erofs: enable large folios for iomap mode

[Jingbo Xu]

Enable large folios for iomap mode.  Then the readahead routine will
pass down large folios containing multiple pages.

Let's enable this for non-compressed format for now, until the
compression part supports large folios later.

When large folios supported, the iomap routine will allocate iomap_page
for each large folio and thus we need iomap_release_folio() and
iomap_invalidate_folio() to free iomap_page when these folios get
recalimed or invalidated.

Signed-off-by: Jingbo Xu <jefflexu at linux.alibaba.com>
---
v2:
- add calling for iomap_release_folio() and iomap_invalidate_folio() to
  support large folios

v1: https://lore.kernel.org/all/20221110074023.8059-1-jefflexu@linux.alibaba.com/
---
 fs/erofs/data.c  | 2 ++
 fs/erofs/inode.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index fe8ac0e163f7..c9526c627dda 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -403,6 +403,8 @@ const struct address_space_operations erofs_raw_access_aops = {
 	.readahead = erofs_readahead,
 	.bmap = erofs_bmap,
 	.direct_IO = noop_direct_IO,
+	.release_folio = iomap_release_folio,
+	.invalidate_folio = iomap_invalidate_folio,
 };
 
 #ifdef CONFIG_FS_DAX
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index ad2a82f2eb4c..e457b8a59ee7 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -295,6 +295,8 @@ static int erofs_fill_inode(struct inode *inode)
 		goto out_unlock;
 	}
 	inode->i_mapping->a_ops = &erofs_raw_access_aops;
+	if (!erofs_is_fscache_mode(inode->i_sb))
+		mapping_set_large_folios(inode->i_mapping);
 #ifdef CONFIG_EROFS_FS_ONDEMAND
 	if (erofs_is_fscache_mode(inode->i_sb))
 		inode->i_mapping->a_ops = &erofs_fscache_access_aops;
-- 
2.19.1.6.gb485710b