ROMFS: Fix up an error in iget removal

Fix up an error in iget removal in which romfs_lookup() making a successful
call to romfs_iget() continues through the negative/error handling (previously
the successful case jumped around the negative/error handling case):

 (1) inode is initialised to NULL at the top of the function, eliminating the
     need for specific negative-inode handling.  This means the positive
     success handling now flows straight through.

 (2) Rename the labels to be clearer about what they mean.

Also make romfs_lookup()'s result variable of type long so as to avoid
32-bit/64-bit conversions with PTR_ERR() and friends.

Based upon a report and patch from Adam Richter.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: "Adam J. Richter" <adam@yggdrasil.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Howells 2008-03-19 17:00:50 -07:00 committed by Linus Torvalds
parent c587f0c0a6
commit 4ebf89845b

View file

@ -340,8 +340,9 @@ static struct dentry *
romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
unsigned long offset, maxoff;
int fslen, res;
struct inode *inode;
long res;
int fslen;
struct inode *inode = NULL;
char fsname[ROMFS_MAXFN]; /* XXX dynamic? */
struct romfs_inode ri;
const char *name; /* got from dentry */
@ -351,7 +352,7 @@ romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
offset = dir->i_ino & ROMFH_MASK;
lock_kernel();
if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0)
goto out;
goto error;
maxoff = romfs_maxsize(dir->i_sb);
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
@ -364,9 +365,9 @@ romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
for(;;) {
if (!offset || offset >= maxoff)
goto out0;
goto success; /* negative success */
if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0)
goto out;
goto error;
/* try to match the first 16 bytes of name */
fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, ROMFH_SIZE);
@ -397,23 +398,14 @@ romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
inode = romfs_iget(dir->i_sb, offset);
if (IS_ERR(inode)) {
res = PTR_ERR(inode);
goto out;
goto error;
}
/*
* it's a bit funky, _lookup needs to return an error code
* (negative) or a NULL, both as a dentry. ENOENT should not
* be returned, instead we need to create a negative dentry by
* d_add(dentry, NULL); and return 0 as no error.
* (Although as I see, it only matters on writable file
* systems).
*/
out0: inode = NULL;
success:
d_add(dentry, inode);
res = 0;
d_add (dentry, inode);
out: unlock_kernel();
error:
unlock_kernel();
return ERR_PTR(res);
}