fs: Preserve error code in get_empty_filp(), part 2

Allocating a file structure in function get_empty_filp() might fail because
of several reasons:
 - not enough memory for file structures
 - operation is not allowed
 - user is over its limit

Currently the function returns NULL in all cases and we loose the exact
reason of the error. All callers of get_empty_filp() assume that the function
can fail with ENFILE only.

Return error through pointer. Change all callers to preserve this error code.

[AV: cleaned up a bit, carved the get_empty_filp() part out into a separate commit
(things remaining here deal with alloc_file()), removed pipe(2) behaviour change]

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/socket.c b/net/socket.c
index 2ca51c719ef9..f4a8c5a0b8d7 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -370,11 +370,11 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
 
         file = alloc_file(&path, FMODE_READ | FMODE_WRITE,
                   &socket_file_ops);
-        if (unlikely(!file)) {
+        if (unlikely(IS_ERR(file))) {
                 /* drop dentry, keep inode */
                 ihold(path.dentry->d_inode);
                 path_put(&path);
-                return ERR_PTR(-ENFILE);
+                return file;
         }
 
         sock->file = file;