diff mbox series

[RFC,02/15] fanotify: Split fsid check from other fid mode checks

Message ID 20210426184201.4177978-3-krisman@collabora.com (mailing list archive)
State New
Headers show
Series File system wide monitoring | expand

Commit Message

Gabriel Krisman Bertazi April 26, 2021, 6:41 p.m. UTC
FAN_ERROR will require fsid, but not necessarily require the filesystem
to expose a file handle.  Split those checks into different functions, so
they can be used separately when creating a mark.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 fs/notify/fanotify/fanotify_user.c | 35 +++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 13 deletions(-)

Comments

Amir Goldstein April 27, 2021, 4:53 a.m. UTC | #1
On Mon, Apr 26, 2021 at 9:42 PM Gabriel Krisman Bertazi
<krisman@collabora.com> wrote:
>
> FAN_ERROR will require fsid, but not necessarily require the filesystem
> to expose a file handle.  Split those checks into different functions, so
> they can be used separately when creating a mark.

Ok for the split, but...

>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
> ---
>  fs/notify/fanotify/fanotify_user.c | 35 +++++++++++++++++++-----------
>  1 file changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index 0332c4afeec3..e0d113e3b65c 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -1055,7 +1055,23 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
>  }
>
>  /* Check if filesystem can encode a unique fid */
> -static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
> +static int fanotify_test_fid(struct path *path)

This helper can take a dentry.

> +{
> +       /*
> +        * We need to make sure that the file system supports at least
> +        * encoding a file handle so user can use name_to_handle_at() to
> +        * compare fid returned with event to the file handle of watched
> +        * objects. However, name_to_handle_at() requires that the
> +        * filesystem also supports decoding file handles.
> +        */
> +       if (!path->dentry->d_sb->s_export_op ||
> +           !path->dentry->d_sb->s_export_op->fh_to_dentry)
> +               return -EOPNOTSUPP;
> +
> +       return 0;
> +}
> +
> +static int fanotify_check_path_fsid(struct path *path, __kernel_fsid_t *fsid)

And so does this helper.
I certainly don't see the need for the _path_ in the helper name.

>  {
>         __kernel_fsid_t root_fsid;
>         int err;
> @@ -1082,17 +1098,6 @@ static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
>             root_fsid.val[1] != fsid->val[1])
>                 return -EXDEV;
>
> -       /*
> -        * We need to make sure that the file system supports at least
> -        * encoding a file handle so user can use name_to_handle_at() to
> -        * compare fid returned with event to the file handle of watched
> -        * objects. However, name_to_handle_at() requires that the
> -        * filesystem also supports decoding file handles.
> -        */
> -       if (!path->dentry->d_sb->s_export_op ||
> -           !path->dentry->d_sb->s_export_op->fh_to_dentry)
> -               return -EOPNOTSUPP;
> -
>         return 0;
>  }
>
> @@ -1230,7 +1235,11 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
>         }
>
>         if (fid_mode) {
> -               ret = fanotify_test_fid(&path, &__fsid);
> +               ret = fanotify_check_path_fsid(&path, &__fsid);
> +               if (ret)
> +                       goto path_put_and_out;
> +
> +               ret = fanotify_test_fid(&path);

Whether _test_ or _check_ please stick to one.

Thanks,
Amir.
diff mbox series

Patch

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 0332c4afeec3..e0d113e3b65c 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -1055,7 +1055,23 @@  SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 }
 
 /* Check if filesystem can encode a unique fid */
-static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
+static int fanotify_test_fid(struct path *path)
+{
+	/*
+	 * We need to make sure that the file system supports at least
+	 * encoding a file handle so user can use name_to_handle_at() to
+	 * compare fid returned with event to the file handle of watched
+	 * objects. However, name_to_handle_at() requires that the
+	 * filesystem also supports decoding file handles.
+	 */
+	if (!path->dentry->d_sb->s_export_op ||
+	    !path->dentry->d_sb->s_export_op->fh_to_dentry)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static int fanotify_check_path_fsid(struct path *path, __kernel_fsid_t *fsid)
 {
 	__kernel_fsid_t root_fsid;
 	int err;
@@ -1082,17 +1098,6 @@  static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid)
 	    root_fsid.val[1] != fsid->val[1])
 		return -EXDEV;
 
-	/*
-	 * We need to make sure that the file system supports at least
-	 * encoding a file handle so user can use name_to_handle_at() to
-	 * compare fid returned with event to the file handle of watched
-	 * objects. However, name_to_handle_at() requires that the
-	 * filesystem also supports decoding file handles.
-	 */
-	if (!path->dentry->d_sb->s_export_op ||
-	    !path->dentry->d_sb->s_export_op->fh_to_dentry)
-		return -EOPNOTSUPP;
-
 	return 0;
 }
 
@@ -1230,7 +1235,11 @@  static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 	}
 
 	if (fid_mode) {
-		ret = fanotify_test_fid(&path, &__fsid);
+		ret = fanotify_check_path_fsid(&path, &__fsid);
+		if (ret)
+			goto path_put_and_out;
+
+		ret = fanotify_test_fid(&path);
 		if (ret)
 			goto path_put_and_out;