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Subject[ 002/109] iscsi-target: Drop bogus struct file usage for iSCSI/SCTP
Date
From: Greg KH <gregkh@linuxfoundation.org>

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@ZenIV.linux.org.uk>

commit bf6932f44a7b3fa7e2246a8b18a44670e5eab6c2 upstream.

>From Al Viro:

BTW, speaking of struct file treatment related to sockets -
there's this piece of code in iscsi:
/*
* The SCTP stack needs struct socket->file.
*/
if ((np->np_network_transport == ISCSI_SCTP_TCP) ||
(np->np_network_transport == ISCSI_SCTP_UDP)) {
if (!new_sock->file) {
new_sock->file = kzalloc(
sizeof(struct file), GFP_KERNEL);

For one thing, as far as I can see it'not true - sctp does *not* depend on
socket->file being non-NULL; it does, in one place, check socket->file->f_flags
for O_NONBLOCK, but there it treats NULL socket->file as "flag not set".
Which is the case here anyway - the fake struct file created in
__iscsi_target_login_thread() (and in iscsi_target_setup_login_socket(), with
the same excuse) do *not* get that flag set.

Moreover, it's a bloody serious violation of a bunch of asserts in VFS;
all struct file instances should come from filp_cachep, via get_empty_filp()
(or alloc_file(), which is a wrapper for it). FWIW, I'm very tempted to
do this and be done with the entire mess:

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Grover <agrover@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/target/iscsi/iscsi_target.c | 22 +----------
drivers/target/iscsi/iscsi_target_core.h | 2 -
drivers/target/iscsi/iscsi_target_login.c | 60 +-----------------------------
3 files changed, 6 insertions(+), 78 deletions(-)

--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -427,19 +427,8 @@ int iscsit_reset_np_thread(

int iscsit_del_np_comm(struct iscsi_np *np)
{
- if (!np->np_socket)
- return 0;
-
- /*
- * Some network transports allocate their own struct sock->file,
- * see if we need to free any additional allocated resources.
- */
- if (np->np_flags & NPF_SCTP_STRUCT_FILE) {
- kfree(np->np_socket->file);
- np->np_socket->file = NULL;
- }
-
- sock_release(np->np_socket);
+ if (np->np_socket)
+ sock_release(np->np_socket);
return 0;
}

@@ -4094,13 +4083,8 @@ int iscsit_close_connection(
kfree(conn->conn_ops);
conn->conn_ops = NULL;

- if (conn->sock) {
- if (conn->conn_flags & CONNFLAG_SCTP_STRUCT_FILE) {
- kfree(conn->sock->file);
- conn->sock->file = NULL;
- }
+ if (conn->sock)
sock_release(conn->sock);
- }
conn->thread_set = NULL;

pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -224,7 +224,6 @@ enum iscsi_timer_flags_table {
/* Used for struct iscsi_np->np_flags */
enum np_flags_table {
NPF_IP_NETWORK = 0x00,
- NPF_SCTP_STRUCT_FILE = 0x01 /* Bugfix */
};

/* Used for struct iscsi_np->np_thread_state */
@@ -511,7 +510,6 @@ struct iscsi_conn {
u16 local_port;
int net_size;
u32 auth_id;
-#define CONNFLAG_SCTP_STRUCT_FILE 0x01
u32 conn_flags;
/* Used for iscsi_tx_login_rsp() */
u32 login_itt;
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -795,22 +795,6 @@ int iscsi_target_setup_login_socket(
}
np->np_socket = sock;
/*
- * The SCTP stack needs struct socket->file.
- */
- if ((np->np_network_transport == ISCSI_SCTP_TCP) ||
- (np->np_network_transport == ISCSI_SCTP_UDP)) {
- if (!sock->file) {
- sock->file = kzalloc(sizeof(struct file), GFP_KERNEL);
- if (!sock->file) {
- pr_err("Unable to allocate struct"
- " file for SCTP\n");
- ret = -ENOMEM;
- goto fail;
- }
- np->np_flags |= NPF_SCTP_STRUCT_FILE;
- }
- }
- /*
* Setup the np->np_sockaddr from the passed sockaddr setup
* in iscsi_target_configfs.c code..
*/
@@ -869,21 +853,15 @@ int iscsi_target_setup_login_socket(

fail:
np->np_socket = NULL;
- if (sock) {
- if (np->np_flags & NPF_SCTP_STRUCT_FILE) {
- kfree(sock->file);
- sock->file = NULL;
- }
-
+ if (sock)
sock_release(sock);
- }
return ret;
}

static int __iscsi_target_login_thread(struct iscsi_np *np)
{
u8 buffer[ISCSI_HDR_LEN], iscsi_opcode, zero_tsih = 0;
- int err, ret = 0, set_sctp_conn_flag, stop;
+ int err, ret = 0, stop;
struct iscsi_conn *conn = NULL;
struct iscsi_login *login;
struct iscsi_portal_group *tpg = NULL;
@@ -894,7 +872,6 @@ static int __iscsi_target_login_thread(s
struct sockaddr_in6 sock_in6;

flush_signals(current);
- set_sctp_conn_flag = 0;
sock = np->np_socket;

spin_lock_bh(&np->np_thread_lock);
@@ -917,35 +894,12 @@ static int __iscsi_target_login_thread(s
spin_unlock_bh(&np->np_thread_lock);
goto out;
}
- /*
- * The SCTP stack needs struct socket->file.
- */
- if ((np->np_network_transport == ISCSI_SCTP_TCP) ||
- (np->np_network_transport == ISCSI_SCTP_UDP)) {
- if (!new_sock->file) {
- new_sock->file = kzalloc(
- sizeof(struct file), GFP_KERNEL);
- if (!new_sock->file) {
- pr_err("Unable to allocate struct"
- " file for SCTP\n");
- sock_release(new_sock);
- /* Get another socket */
- return 1;
- }
- set_sctp_conn_flag = 1;
- }
- }
-
iscsi_start_login_thread_timer(np);

conn = kzalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
if (!conn) {
pr_err("Could not allocate memory for"
" new connection\n");
- if (set_sctp_conn_flag) {
- kfree(new_sock->file);
- new_sock->file = NULL;
- }
sock_release(new_sock);
/* Get another socket */
return 1;
@@ -955,9 +909,6 @@ static int __iscsi_target_login_thread(s
conn->conn_state = TARG_CONN_STATE_FREE;
conn->sock = new_sock;

- if (set_sctp_conn_flag)
- conn->conn_flags |= CONNFLAG_SCTP_STRUCT_FILE;
-
pr_debug("Moving to TARG_CONN_STATE_XPT_UP.\n");
conn->conn_state = TARG_CONN_STATE_XPT_UP;

@@ -1205,13 +1156,8 @@ old_sess_out:
iscsi_release_param_list(conn->param_list);
conn->param_list = NULL;
}
- if (conn->sock) {
- if (conn->conn_flags & CONNFLAG_SCTP_STRUCT_FILE) {
- kfree(conn->sock->file);
- conn->sock->file = NULL;
- }
+ if (conn->sock)
sock_release(conn->sock);
- }
kfree(conn);

if (tpg) {



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