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>

1 files changed, 26 insertions, 24 deletions

diff --git a/fs/statfs.c b/fs/statfs.c
index 4ef021f3b612..6a305709a4da 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -7,33 +7,35 @@
 #include <linux/security.h>
 #include <linux/uaccess.h>
 
-int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
 {
-        int retval = -ENODEV;
-
-        if (dentry) {
-                retval = -ENOSYS;
-                if (dentry->d_sb->s_op->statfs) {
-                        memset(buf, 0, sizeof(*buf));
-                        retval = security_sb_statfs(dentry);
-                        if (retval)
-                                return retval;
-                        retval = dentry->d_sb->s_op->statfs(dentry, buf);
-                        if (retval == 0 && buf->f_frsize == 0)
-                                buf->f_frsize = buf->f_bsize;
-                }
-        }
+        int retval;
+
+        if (!dentry->d_sb->s_op->statfs)
+                return -ENOSYS;
+
+        memset(buf, 0, sizeof(*buf));
+        retval = security_sb_statfs(dentry);
+        if (retval)
+                return retval;
+        retval = dentry->d_sb->s_op->statfs(dentry, buf);
+        if (retval == 0 && buf->f_frsize == 0)
+                buf->f_frsize = buf->f_bsize;
         return retval;
 }
 
+int vfs_statfs(struct path *path, struct kstatfs *buf)
+{
+        return statfs_by_dentry(path->dentry, buf);
+}
 EXPORT_SYMBOL(vfs_statfs);
 
-static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
+static int do_statfs_native(struct path *path, struct statfs *buf)
 {
         struct kstatfs st;
         int retval;
 
-        retval = vfs_statfs(dentry, &st);
+        retval = vfs_statfs(path, &st);
         if (retval)
                 return retval;
 
@@ -72,12 +74,12 @@ static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
         return 0;
 }
 
-static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
+static int do_statfs64(struct path *path, struct statfs64 *buf)
 {
         struct kstatfs st;
         int retval;
 
-        retval = vfs_statfs(dentry, &st);
+        retval = vfs_statfs(path, &st);
         if (retval)
                 return retval;
 
@@ -107,7 +109,7 @@ SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, b
         error = user_path(pathname, &path);
         if (!error) {
                 struct statfs tmp;
-                error = vfs_statfs_native(path.dentry, &tmp);
+                error = do_statfs_native(&path, &tmp);
                 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
                         error = -EFAULT;
                 path_put(&path);
@@ -125,7 +127,7 @@ SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct stat
         error = user_path(pathname, &path);
         if (!error) {
                 struct statfs64 tmp;
-                error = vfs_statfs64(path.dentry, &tmp);
+                error = do_statfs64(&path, &tmp);
                 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
                         error = -EFAULT;
                 path_put(&path);
@@ -143,7 +145,7 @@ SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
         file = fget(fd);
         if (!file)
                 goto out;
-        error = vfs_statfs_native(file->f_path.dentry, &tmp);
+        error = do_statfs_native(&file->f_path, &tmp);
         if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
                 error = -EFAULT;
         fput(file);
@@ -164,7 +166,7 @@ SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user
         file = fget(fd);
         if (!file)
                 goto out;
-        error = vfs_statfs64(file->f_path.dentry, &tmp);
+        error = do_statfs64(&file->f_path, &tmp);
         if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
                 error = -EFAULT;
         fput(file);
@@ -183,7 +185,7 @@ SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
         if (!s)
                 return -EINVAL;
 
-        err = vfs_statfs(s->s_root, &sbuf);
+        err = statfs_by_dentry(s->s_root, &sbuf);
         drop_super(s);
         if (err)
                 return err;