[RFC 03/19] cachefiles: refactor cachefiles_adjust_size()

[Jeffle Xu]

In demand-read mode, fs using fscache for demand-read doesn't know the
exact file size of the data blob file, and the input @object_size
parameter of fscache_acquire_cookie() could be fake in this case.

Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
---
 fs/cachefiles/interface.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 51c968cd00a6..b85051250cb7 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -110,6 +110,7 @@ static int cachefiles_adjust_size(struct cachefiles_object *object)
 {
 	struct iattr newattrs;
 	struct file *file = object->file;
+	struct cachefiles_cache *cache = object->volume->cache;
 	uint64_t ni_size;
 	loff_t oi_size;
 	int ret;
@@ -123,6 +124,9 @@ static int cachefiles_adjust_size(struct cachefiles_object *object)
 	if (!file)
 		return -ENOBUFS;
 
+	if (cache->mode == CACHEFILES_MODE_DEMAND)
+		return 0;
+
 	oi_size = i_size_read(file_inode(file));
 	if (oi_size == ni_size)
 		return 0;
-- 
2.27.0