pass a struct path to vfs_statfs

We'll need the path to implement the flags field for statvfs support.
We do have it available in all callers except:

 - ecryptfs_statfs.  This one doesn't actually need vfs_statfs but just
   needs to do a caller to the lower filesystem statfs method.
 - sys_ustat.  Add a non-exported statfs_by_dentry helper for it which
   doesn't won't be able to fill out the flags field later on.

In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
of the misleading vfs prefix.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 6 insertions, 2 deletions

diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c
index 2906077ac798..a2603e7c0bb5 100644
--- a/fs/cachefiles/bind.c
+++ b/fs/cachefiles/bind.c
@@ -146,7 +146,7 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache)
                 goto error_unsupported;
 
         /* get the cache size and blocksize */
-        ret = vfs_statfs(root, &stats);
+        ret = vfs_statfs(&path, &stats);
         if (ret < 0)
                 goto error_unsupported;
 
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index c2413561ea75..24eb0d37241a 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -683,6 +683,10 @@ int cachefiles_has_space(struct cachefiles_cache *cache,
                          unsigned fnr, unsigned bnr)
 {
         struct kstatfs stats;
+        struct path path = {
+                .mnt    = cache->mnt,
+                .dentry = cache->mnt->mnt_root,
+        };
         int ret;
 
         //_enter("{%llu,%llu,%llu,%llu,%llu,%llu},%u,%u",
@@ -697,7 +701,7 @@ int cachefiles_has_space(struct cachefiles_cache *cache,
         /* find out how many pages of blockdev are available */
         memset(&stats, 0, sizeof(stats));
 
-        ret = vfs_statfs(cache->mnt->mnt_root, &stats);
+        ret = vfs_statfs(&path, &stats);
         if (ret < 0) {
                 if (ret == -EIO)
                         cachefiles_io_error(cache, "statfs failed");