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

Tom Rini trini at konsulko.com
Mon Dec 14 20:56:00 CET 2015


On Mon, Dec 14, 2015 at 12:32:13PM -0700, Stephen Warren wrote:
> 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;

Ah, yes, I missed that one, good catch, thanks!

-- 
Tom
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