Re: [PATCH 4/4] orangefs: simplify compat ioctl handling

[Al Viro <viro@ZenIV.linux.org.uk>]

On Thu, May 31, 2018 at 04:54:06PM -0400, Mike Marshall wrote:
> Thanks for the cleanup. This runs through xfstests with no regressions
> on 4.17-rc7.
> 
> I studied what to do about the sparse warning, looked at the code, and
> looked for hints from the original authors in the pvfs svn commit messages.
> 
> No luck with the old commit messages.
> 
> I got the sparse warning to quit with this change, which also runs through
> xfstests with no regressions, does it seem OK?
> 
> 
> $ git diff
> diff --git a/fs/orangefs/protocol.h b/fs/orangefs/protocol.h
> index 61ee8d64c842..d403cf29a99b 100644
> --- a/fs/orangefs/protocol.h
> +++ b/fs/orangefs/protocol.h
> @@ -342,7 +342,7 @@ enum {
>   * that may be 32 bit!
>   */
>  struct ORANGEFS_dev_map_desc {
> -       void *ptr;
> +       void __user *ptr;
>         __s32 total_size;
>         __s32 size;
>         __s32 count;

You want more than that -
--- a/fs/orangefs/orangefs-bufmap.c
+++ b/fs/orangefs/orangefs-bufmap.c
@@ -138,7 +138,7 @@ static int get(struct slot_map *m)
 
 /* used to describe mapped buffers */
 struct orangefs_bufmap_desc {
-       void *uaddr;                    /* user space address pointer */
+       void __user *uaddr;             /* user space address pointer */
        struct page **page_array;       /* array of mapped pages */
        int array_count;                /* size of above arrays */
        struct list_head list_link;

to go with it.  FWIW, the following takes care of almost all sparse
warnings in there; up to you whether to split it or not:

diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index 26358efbf794..84f44365bfb3 100644
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -544,7 +544,7 @@ static int orangefs_fault(struct vm_fault *vmf)
 	return filemap_fault(vmf);
 }
 
-const struct vm_operations_struct orangefs_file_vm_ops = {
+static const struct vm_operations_struct orangefs_file_vm_ops = {
 	.fault = orangefs_fault,
 	.map_pages = filemap_map_pages,
 	.page_mkwrite = filemap_page_mkwrite,
diff --git a/fs/orangefs/orangefs-bufmap.c b/fs/orangefs/orangefs-bufmap.c
index 4f927023d095..0a29f57d4c8f 100644
--- a/fs/orangefs/orangefs-bufmap.c
+++ b/fs/orangefs/orangefs-bufmap.c
@@ -138,7 +138,7 @@ static int get(struct slot_map *m)
 
 /* used to describe mapped buffers */
 struct orangefs_bufmap_desc {
-	void *uaddr;			/* user space address pointer */
+	void __user *uaddr;		/* user space address pointer */
 	struct page **page_array;	/* array of mapped pages */
 	int array_count;		/* size of above arrays */
 	struct list_head list_link;
@@ -215,19 +215,6 @@ int orangefs_bufmap_shift_query(void)
 static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
 static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
 
-/*
- * orangefs_get_bufmap_init
- *
- * If bufmap_init is 1, then the shared memory system, including the
- * buffer_index_array, is available.  Otherwise, it is not.
- *
- * returns the value of bufmap_init
- */
-int orangefs_get_bufmap_init(void)
-{
-	return __orangefs_bufmap ? 1 : 0;
-}
-
 
 static struct orangefs_bufmap *
 orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c
index 6e35f2f3c897..0732cb08173e 100644
--- a/fs/orangefs/orangefs-debugfs.c
+++ b/fs/orangefs/orangefs-debugfs.c
@@ -114,7 +114,7 @@ static const struct seq_operations help_debug_ops = {
 	.show	= help_show,
 };
 
-const struct file_operations debug_help_fops = {
+static const struct file_operations debug_help_fops = {
 	.owner		= THIS_MODULE,
 	.open           = orangefs_debug_help_open,
 	.read           = seq_read,
diff --git a/fs/orangefs/protocol.h b/fs/orangefs/protocol.h
index 61ee8d64c842..d403cf29a99b 100644
--- a/fs/orangefs/protocol.h
+++ b/fs/orangefs/protocol.h
@@ -342,7 +342,7 @@ enum {
  * that may be 32 bit!
  */
 struct ORANGEFS_dev_map_desc {
-	void *ptr;
+	void __user *ptr;
 	__s32 total_size;
 	__s32 size;
 	__s32 count;
diff --git a/fs/orangefs/waitqueue.c b/fs/orangefs/waitqueue.c
index 0577d6dba8c8..3de323f17506 100644
--- a/fs/orangefs/waitqueue.c
+++ b/fs/orangefs/waitqueue.c
@@ -17,8 +17,11 @@
 #include "orangefs-kernel.h"
 #include "orangefs-bufmap.h"
 
-static int wait_for_matching_downcall(struct orangefs_kernel_op_s *, long, bool);
-static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *);
+static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op,
+				      long timeout, bool interruptible)
+	__acquires(op->lock);
+static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
+	__releases(op->lock);
 
 /*
  * What we do in this function is to walk the list of operations that are
@@ -245,7 +248,8 @@ bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op)
  * Change an op to the "given up" state and remove it from its list.
  */
 static void
-	orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
+orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
+	__releases(op->lock)
 {
 	/*
 	 * handle interrupted cases depending on what state we were in when
@@ -315,6 +319,7 @@ static void
 static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op,
 				      long timeout,
 				      bool interruptible)
+	__acquires(op->lock)
 {
 	long n;