Syslinux - Mar 2010 - [PATCH] fs: fix call to fs_ops->readdir

Check if fs_ops->readdir is available before calling it.
At least PXELINUX doesn't implement it.

Signed-off-by: Sebastian Herbszt <herbszt at gmx.de>

diff --git a/core/fs/readdir.c b/core/fs/readdir.c
index d2b112b..d20fc33 100644
--- a/core/fs/readdir.c
+++ b/core/fs/readdir.c
@@ -28,8 +28,11 @@ struct dirent *readdir(DIR *dir)
     struct file *dd_dir = (struct file *)dir;
     int rv = -1;
     
-    if (dd_dir)
-	rv = dd_dir->fs->fs_ops->readdir(dd_dir, &buf);
+    if (dd_dir) {
+        if (dd_dir->fs->fs_ops->readdir) {
+	    rv = dd_dir->fs->fs_ops->readdir(dd_dir, &buf);
+        }
+    }
 
     return rv < 0 ? NULL : &buf;
 }

On Sun, Mar 7, 2010 at 10:02 AM, Sebastian Herbszt <herbszt at gmx.de>
wrote:
> Check if fs_ops->readdir is available before calling it.
> At least PXELINUX doesn't implement it.
>
> Signed-off-by: Sebastian Herbszt <herbszt at gmx.de>
>
> diff --git a/core/fs/readdir.c b/core/fs/readdir.c
> index d2b112b..d20fc33 100644
> --- a/core/fs/readdir.c
> +++ b/core/fs/readdir.c
> @@ -28,8 +28,11 @@ struct dirent *readdir(DIR *dir)
> ? ? struct file *dd_dir = (struct file *)dir;
> ? ? int rv = -1;
>
> - ? ?if (dd_dir)
> - ? ? ? rv = dd_dir->fs->fs_ops->readdir(dd_dir, &buf);
> + ? ?if (dd_dir) {
> + ? ? ? ?if (dd_dir->fs->fs_ops->readdir) {
> + ? ? ? ? ? rv = dd_dir->fs->fs_ops->readdir(dd_dir, &buf);
> + ? ? ? ?}
> + ? ?}
>
> ? ? return rv < 0 ? NULL : &buf;
> ?}
>
This brings up a few questions.

1) This appears to be for Syslinux-4.00 if I'm looking at -pre36 and
the code correct.  Is this assumption correct?

2) Since I release the initial run of code for the directory-related
functions and 3.x, I had posted a git archive as requested and never
heard back from anyone again.  This can probably be chalked up to
"life happens."

3) I'd like to investigate the completeness of the directory-related
functions and see about completing them if they are not.  I also have
an improved version of ROSH (Read-Only SHell) although I still do not
consider it complete.

-Gene

I wrote:
> Check if fs_ops->readdir is available before calling it.
> At least PXELINUX doesn't implement it.
Anything wrong with the patch?

- Sebastian