[PATCH] JFS: return correct error when i-node allocation failed

I have seen confusing behavior on JFS when I injected many intentional
slab allocation errors. The cp command failed with no disk space error
with enough disk space.

This patch makes:

- change the return value in case slab allocation failures happen
  from -ENOSPC to -ENOMEM

- ialloc() return error code so that the caller can know the reason
  of failures

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
(cherry picked from 2b46f77976f798f3fe800809a1d0ed38763c71c8 commit)

fs/jfs/jfs_dtree.c

@@ -3780,13 +3780,13 @@ static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
 	lkey.name = (wchar_t *) kmalloc((JFS_NAME_MAX + 1) * sizeof(wchar_t),
 					GFP_KERNEL);
 	if (lkey.name == NULL)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	rkey.name = (wchar_t *) kmalloc((JFS_NAME_MAX + 1) * sizeof(wchar_t),
 					GFP_KERNEL);
 	if (rkey.name == NULL) {
 		kfree(lkey.name);
-		return -ENOSPC;
+		return -ENOMEM;
 	}
 
 	/* get left and right key */