Re: [patch] Combine path_put and path_put_conditional

[Ingo Oeser]

Hi Andreas,

On Friday 28 September 2007, Andreas Gruenbacher wrote:
> The name path_put_conditional (formerly, dput_path) is a little unclear.
> Replace (path_put_conditional + path_put) with path_walk_put_both,
> "put a pair of paths after a path_walk" (see the kerneldoc).
 ^

So why not name it path_walk_put_pair() then?

Rationale: "_both" is just counting, "_pair" 
means they are related somehow.


Best regards

Ingo Oeser
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Re: [patch] Combine path_put and path_put_conditional

[Jan Blunck]

On Fri, Sep 28, Andreas Gruenbacher wrote:

> The name path_put_conditional (formerly, dput_path) is a little unclear.
> Replace (path_put_conditional + path_put) with path_walk_put_both,
> "put a pair of paths after a path_walk" (see the kerneldoc).

Hmm, I don't know. To put both the nd and path is at the moment only used in
some error paths. I have another series of patches pending which is using
path_put_conditional outside of error paths. So please don't remove
it. Besides that the naming completely hides that the conditional release of
the vfsmount reference. Besides that I would name it path_put_both() just to
make it more "beautiful" wrt the other path_put*() functions.

> @@ -996,8 +1006,8 @@ return_reval:
>  return_base:
>   return 0;
>  out_dput:
> - path_put_conditional(, nd);
> - break;
> + path_walk_put_both(, >path);
> + goto return_err;
>   }
>   path_put(>path);
>  return_err:
> @@ -1777,11 +1787,15 @@ ok:
>   return 0;
>  
>  exit_dput:
> - path_put_conditional(, nd);
> + path_walk_put_both(, >path);
> + goto exit_intent;
> +
>  exit:
> + path_put(>path);
> +
> +exit_intent:
>   if (!IS_ERR(nd->intent.open.file))
>   release_open_intent(nd);
> - path_put(>path);
>   return error;
>  
>  do_link:

IMHO introducing another label just to use it here isn't worth the change.
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Re: [patch] Combine path_put and path_put_conditional

[Christoph Hellwig]

On Fri, Sep 28, 2007 at 10:43:50PM +0200, Andreas Gruenbacher wrote:
> Here is another cleanup on top of Jan's set. Comments?
> 
> 
> The name path_put_conditional (formerly, dput_path) is a little unclear.
> Replace (path_put_conditional + path_put) with path_walk_put_both,
> "put a pair of paths after a path_walk" (see the kerneldoc).

I think this function is a good idea.  The name seems odd to me, but
I don't really have a better idea either.

> +static void path_walk_put_both(struct path *path1, struct path *path2)
> +{
> + dput(path1->dentry);
> + dput(path2->dentry);
> + mntput(path1->mnt);
> + if (path1->mnt != path2->mnt)
> + mntput(path2->mnt);
>  }

Why do you opencode the path_put for path1?

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Re: [patch] Combine path_put and path_put_conditional

[Christoph Hellwig]

On Fri, Sep 28, 2007 at 10:43:50PM +0200, Andreas Gruenbacher wrote:
 Here is another cleanup on top of Jan's set. Comments?
 
 
 The name path_put_conditional (formerly, dput_path) is a little unclear.
 Replace (path_put_conditional + path_put) with path_walk_put_both,
 put a pair of paths after a path_walk (see the kerneldoc).

I think this function is a good idea.  The name seems odd to me, but
I don't really have a better idea either.

 +static void path_walk_put_both(struct path *path1, struct path *path2)
 +{
 + dput(path1-dentry);
 + dput(path2-dentry);
 + mntput(path1-mnt);
 + if (path1-mnt != path2-mnt)
 + mntput(path2-mnt);
  }

Why do you opencode the path_put for path1?

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Re: [patch] Combine path_put and path_put_conditional

[Jan Blunck]

On Fri, Sep 28, Andreas Gruenbacher wrote:

 The name path_put_conditional (formerly, dput_path) is a little unclear.
 Replace (path_put_conditional + path_put) with path_walk_put_both,
 put a pair of paths after a path_walk (see the kerneldoc).

Hmm, I don't know. To put both the nd and path is at the moment only used in
some error paths. I have another series of patches pending which is using
path_put_conditional outside of error paths. So please don't remove
it. Besides that the naming completely hides that the conditional release of
the vfsmount reference. Besides that I would name it path_put_both() just to
make it more beautiful wrt the other path_put*() functions.

 @@ -996,8 +1006,8 @@ return_reval:
  return_base:
   return 0;
  out_dput:
 - path_put_conditional(next, nd);
 - break;
 + path_walk_put_both(next, nd-path);
 + goto return_err;
   }
   path_put(nd-path);
  return_err:
 @@ -1777,11 +1787,15 @@ ok:
   return 0;
  
  exit_dput:
 - path_put_conditional(path, nd);
 + path_walk_put_both(path, nd-path);
 + goto exit_intent;
 +
  exit:
 + path_put(nd-path);
 +
 +exit_intent:
   if (!IS_ERR(nd-intent.open.file))
   release_open_intent(nd);
 - path_put(nd-path);
   return error;
  
  do_link:

IMHO introducing another label just to use it here isn't worth the change.
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Re: [patch] Combine path_put and path_put_conditional

[Ingo Oeser]

Hi Andreas,

On Friday 28 September 2007, Andreas Gruenbacher wrote:
 The name path_put_conditional (formerly, dput_path) is a little unclear.
 Replace (path_put_conditional + path_put) with path_walk_put_both,
 put a pair of paths after a path_walk (see the kerneldoc).
 ^

So why not name it path_walk_put_pair() then?

Rationale: _both is just counting, _pair 
means they are related somehow.


Best regards

Ingo Oeser
-
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[patch] Combine path_put and path_put_conditional

[Andreas Gruenbacher]

Here is another cleanup on top of Jan's set. Comments?


The name path_put_conditional (formerly, dput_path) is a little unclear.
Replace (path_put_conditional + path_put) with path_walk_put_both,
"put a pair of paths after a path_walk" (see the kerneldoc).

Signed-off-by: Andreas Gruenbacher <[EMAIL PROTECTED]>

Index: linux-2.6/fs/namei.c
===
--- linux-2.6.orig/fs/namei.c
+++ linux-2.6/fs/namei.c
@@ -582,11 +582,22 @@ fail:
return PTR_ERR(link);
 }
 
-static void path_put_conditional(struct path *path, struct nameidata *nd)
-{
-   dput(path->dentry);
-   if (path->mnt != nd->path.mnt)
-   mntput(path->mnt);
+/**
+ * path_walk_put_both - put a pair of paths after a path_walk
+ * @path1: first path to put
+ * @path2: second path to put
+ *
+ * When walking a path we keep the same vfsmnt reference while on the same
+ * filesystem, and grab a reference to the new vfsmnt when crossing mount
+ * points. Put both @path1 and @path2 under this assumption.
+ */
+static void path_walk_put_both(struct path *path1, struct path *path2)
+{
+   dput(path1->dentry);
+   dput(path2->dentry);
+   mntput(path1->mnt);
+   if (path1->mnt != path2->mnt)
+   mntput(path2->mnt);
 }
 
 static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
@@ -654,8 +665,7 @@ static inline int do_follow_link(struct 
nd->depth--;
return err;
 loop:
-   path_put_conditional(path, nd);
-   path_put(>path);
+   path_walk_put_both(path, >path);
return err;
 }
 
@@ -996,8 +1006,8 @@ return_reval:
 return_base:
return 0;
 out_dput:
-   path_put_conditional(, nd);
-   break;
+   path_walk_put_both(, >path);
+   goto return_err;
}
path_put(>path);
 return_err:
@@ -1777,11 +1787,15 @@ ok:
return 0;
 
 exit_dput:
-   path_put_conditional(, nd);
+   path_walk_put_both(, >path);
+   goto exit_intent;
+
 exit:
+   path_put(>path);
+
+exit_intent:
if (!IS_ERR(nd->intent.open.file))
release_open_intent(nd);
-   path_put(>path);
return error;
 
 do_link:
-
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[patch] Combine path_put and path_put_conditional

[Andreas Gruenbacher]

Here is another cleanup on top of Jan's set. Comments?


The name path_put_conditional (formerly, dput_path) is a little unclear.
Replace (path_put_conditional + path_put) with path_walk_put_both,
put a pair of paths after a path_walk (see the kerneldoc).

Signed-off-by: Andreas Gruenbacher [EMAIL PROTECTED]

Index: linux-2.6/fs/namei.c
===
--- linux-2.6.orig/fs/namei.c
+++ linux-2.6/fs/namei.c
@@ -582,11 +582,22 @@ fail:
return PTR_ERR(link);
 }
 
-static void path_put_conditional(struct path *path, struct nameidata *nd)
-{
-   dput(path-dentry);
-   if (path-mnt != nd-path.mnt)
-   mntput(path-mnt);
+/**
+ * path_walk_put_both - put a pair of paths after a path_walk
+ * @path1: first path to put
+ * @path2: second path to put
+ *
+ * When walking a path we keep the same vfsmnt reference while on the same
+ * filesystem, and grab a reference to the new vfsmnt when crossing mount
+ * points. Put both @path1 and @path2 under this assumption.
+ */
+static void path_walk_put_both(struct path *path1, struct path *path2)
+{
+   dput(path1-dentry);
+   dput(path2-dentry);
+   mntput(path1-mnt);
+   if (path1-mnt != path2-mnt)
+   mntput(path2-mnt);
 }
 
 static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
@@ -654,8 +665,7 @@ static inline int do_follow_link(struct 
nd-depth--;
return err;
 loop:
-   path_put_conditional(path, nd);
-   path_put(nd-path);
+   path_walk_put_both(path, nd-path);
return err;
 }
 
@@ -996,8 +1006,8 @@ return_reval:
 return_base:
return 0;
 out_dput:
-   path_put_conditional(next, nd);
-   break;
+   path_walk_put_both(next, nd-path);
+   goto return_err;
}
path_put(nd-path);
 return_err:
@@ -1777,11 +1787,15 @@ ok:
return 0;
 
 exit_dput:
-   path_put_conditional(path, nd);
+   path_walk_put_both(path, nd-path);
+   goto exit_intent;
+
 exit:
+   path_put(nd-path);
+
+exit_intent:
if (!IS_ERR(nd-intent.open.file))
release_open_intent(nd);
-   path_put(nd-path);
return error;
 
 do_link:
-
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