In the __cachefiles_prepare_write function, DIO aligns blocks using
PAGE_SIZE as the unit. And currently cachefiles_add_cache() binds
cache->bsize with the requirement that it must not exceed PAGE_SIZE.
However, if cache->bsize is smaller than PAGE_SIZE, the calculated block
count will be incorrect in __cachefiles_prepare_write().
Set the block size to cache->bsize to resolve this issue.
Fixes: 047487c947e8 ("cachefiles: Implement the I/O routines")
Signed-off-by: Zizhi Wo <wozizhi@xxxxxxxxxx>
---
fs/cachefiles/io.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index a91acd03ee12..59c5c08f921a 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -524,10 +524,10 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
struct cachefiles_cache *cache = object->volume->cache;
loff_t start = *_start, pos;
size_t len = *_len;
- int ret;
+ int ret, block_size = cache->bsize;
/* Round to DIO size */
- start = round_down(*_start, PAGE_SIZE);
+ start = round_down(*_start, block_size);
if (start != *_start || *_len > upper_len) {
/* Probably asked to cache a streaming write written into the
* pagecache when the cookie was temporarily out of service to
@@ -537,7 +537,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
return -ENOBUFS;
}
- *_len = round_up(len, PAGE_SIZE);
+ *_len = round_up(len, block_size);
/* We need to work out whether there's sufficient disk space to perform
* the write - but we can skip that check if we have space already
@@ -563,7 +563,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
* space, we need to see if it's fully allocated. If it's not, we may
* want to cull it.
*/
- if (cachefiles_has_space(cache, 0, *_len / PAGE_SIZE,
+ if (cachefiles_has_space(cache, 0, *_len / block_size,
cachefiles_has_space_check) == 0)
return 0; /* Enough space to simply overwrite the whole block */
@@ -595,7 +595,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
return ret;
check_space:
- return cachefiles_has_space(cache, 0, *_len / PAGE_SIZE,
+ return cachefiles_has_space(cache, 0, *_len / block_size,
cachefiles_has_space_for_write);
}
--
2.39.2
