JFFS2 crash fix

[Andrew Lunn]

On Mon, Jul 19, 2004 at 02:32:05PM +0200, ?yvind Harboe wrote:
> 
> 
> 
> 
> -- 
> ?yvind Harboe
> http://www.zylin.com
> 

> Index: ChangeLog
> ===================================================================
> RCS file: /cvs/ecos/ecos/packages/fs/jffs2/current/ChangeLog,v
> retrieving revision 1.34
> diff -w -u -r1.34 ChangeLog
> --- ChangeLog	29 Apr 2004 07:16:10 -0000	1.34
> +++ ChangeLog	19 Jul 2004 12:30:27 -0000
> @@ -1,3 +1,9 @@
> +2004-07-19  Oyvind Harboe <oyvind.harboe@zylin.com>
> +	
> +	* src/dir-ecos.c:
> +	* src/fs-ecos.c:
> +	Fix problems with errors being propegated as faux-pointers.
> +	
>  2004-04-19  Oyvind Harboe <oyvind.harboe@zylin.com>
>  	
>  	* src/build.c: JFFS2 can now be used as a write-once, read many mode
> Index: src/dir-ecos.c
> ===================================================================
> RCS file: /cvs/ecos/ecos/packages/fs/jffs2/current/src/dir-ecos.c,v
> retrieving revision 1.5
> diff -w -u -r1.5 dir-ecos.c
> --- src/dir-ecos.c	11 Dec 2003 23:33:54 -0000	1.5
> +++ src/dir-ecos.c	19 Jul 2004 12:30:27 -0000
> @@ -48,9 +48,11 @@
>  	up(&dir_f->sem);
>  	if (ino) {
>  		inode = jffs2_iget(dir_i->i_sb, ino);
> -		if (!inode) {
> +		if (IS_ERR(inode)) {
>  			printk("jffs2_iget() failed for ino #%u\n", ino);
> -			return (ERR_PTR(-EIO));
> +			// NOTE! inode is *not* a pointer here, but an
> +			// error code we propagate.
> +			return inode;
>  		}
>  	}

This is not a complete fix. jffs2_iget can return 0 when malloc
fails. For this to work correctly you need to modify jffs2_iget so
that it returns ERR_PTR(-ENOMEM) when out of memory. Also i don't like
the comment. The IS_ERR() macro call should be enought to make it
clear it could be an error code. 

>  
> Index: src/fs-ecos.c
> ===================================================================
> RCS file: /cvs/ecos/ecos/packages/fs/jffs2/current/src/fs-ecos.c,v
> retrieving revision 1.27
> diff -w -u -r1.27 fs-ecos.c
> --- src/fs-ecos.c	21 Apr 2004 18:51:21 -0000	1.27
> +++ src/fs-ecos.c	19 Jul 2004 12:30:28 -0000
> @@ -302,7 +302,7 @@
>  	d = jffs2_lookup(dir, name, namelen);
>  	D2(printf("find_entry got dir = %x\n", d));
>  
> -	if (d == NULL)
> +	if ((d==NULL)||IS_ERR(d))
>  		return ENOENT;

You modified the code above so that it passed back the error code and
now you throw that information away and return ENOENT. Why not return
the error code?

        Andrew