[U-Boot] [PATCH] fs: ext4: Remove ext4fs_free_node()

[Stephen Warren <swarren@wwwdotorg.org>]

On 12/09/2015 05:54 PM, Tom Rini wrote:
> The function ext4fs_free_node() exists for dealing with "dirnode"
> structures that we allocate.  However, we do not allocate these
> dynamically as needed but rather as a single instance in ext4fs_mount()
> that we zalloc().  Coverity scan notes that in two places we're doing
> what it calls a "Free of address-of expression" as we were free()'ing
> oldnode.  However, oldnode was never directly allocated, nor any other
> instance which we were calling ext4fs_free_node() on.  Removing this
> structure allows us to also restructure ext4fs_close() slightlu too.
>
> Tested on OMAP4 Pandaboard with Fedora 23 (/boot is ext4) as well as
> reading and writing files from / to /boot and vice-versa and confirming
> they read back again correctly.

I think if this change was valid, then we could delete the global 
variable ext4fs_file, and replace all references to it with a reference 
to the dirnode member in struct ext2_data?

Anyway, I believe that the-value-pointed-at-by-ext4fs_file is 
dynamically allocated outside struct ext2_data sometimes:

(All line number references relative to 5076c64a08d2 "Merge branch 
'master' of git://git.denx.de/u-boot-spi")

2187 int ext4fs_open(const char *filename, loff_t *len)
...
2196	status = ext4fs_find_file(filename, &ext4fs_root->diropen, ...
...
2208	ext4fs_file = fdiro;

calls

2163 int ext4fs_find_file(...
2164	struct ext2fs_node **foundnode, int expecttype)
...
2173	status = ext4fs_find_file1(path, rootnode, foundnode, ...

calls

2063 static int ext4fs_find_file1(const char *currpath,
...
2105		found = ext4fs_iterate_dir(currnode, name, &currnode,...
...
2154 			*currfound = currnode;

calls:

fs/ext4/ext4_common.c:
1896 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
...
1941			fdiro = zalloc(sizeof(struct ext2fs_node));
...
1991					*fnode = fdiro;