Re: [RFC-v4 11/12] iscsi-target: Add misc utility and debug logic
From: Mike Christie
Date: Tue Mar 22 2011 - 00:04:48 EST
On 03/20/2011 04:31 AM, Nicholas A. Bellinger wrote
+
+/*
+ * Called with cmd->r2t_lock held.
+ */
+void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
+{
+ list_del(&r2t->r2t_list);
+ kmem_cache_free(lio_r2t_cache, r2t);
+}
+
+void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
+{
+ struct iscsi_r2t *r2t, *r2t_tmp;
+
+ spin_lock_bh(&cmd->r2t_lock);
+ list_for_each_entry_safe(r2t, r2t_tmp,&cmd->cmd_r2t_list, r2t_list) {
+ list_del(&r2t->r2t_list);
+ kmem_cache_free(lio_r2t_cache, r2t);
I think that is iscsit_free_r2t()
+ }
+ spin_unlock_bh(&cmd->r2t_lock);
+}
+
+/*
+ * May be called from interrupt context.
How does this get called from interrupt context? Is it a real interrupt
or a soft irq? I could not find the code path.
+
+struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
+ struct iscsi_cmd *cmd,
+ u32 r2t_sn)
+{
+ struct iscsi_r2t *r2t;
+
+ spin_lock_bh(&cmd->r2t_lock);
+ list_for_each_entry(r2t,&cmd->cmd_r2t_list, r2t_list) {
+ if (r2t->r2t_sn == r2t_sn)
+ break;
+ }
+ spin_unlock_bh(&cmd->r2t_lock);
+
+ return (r2t) ? r2t : NULL;
Don't need "( ")".
+}
+
+#define SERIAL_BITS 31
+#define MAX_BOUND (u32)2147483647UL
+
+static inline int serial_lt(u32 x, u32 y)
+{
+ return (x != y)&& (((x< y)&& ((y - x)< MAX_BOUND)) ||
+ ((x> y)&& ((x - y)> MAX_BOUND)));
+}
+
+static inline int serial_lte(u32 x, u32 y)
+{
+ return (x == y) ? 1 : serial_lt(x, y);
+}
+
+static inline int serial_gt(u32 x, u32 y)
+{
+ return (x != y)&& (((x< y)&& ((y - x)> MAX_BOUND)) ||
+ ((x> y)&& ((x - y)< MAX_BOUND)));
+}
+
+static inline int serial_gte(u32 x, u32 y)
+{
+ return (x == y) ? 1 : serial_gt(x, y);
+}
You should merged these with libiscsi.c's iscsi_sna_* and put in
iscsi_proto.h.
I think this is not iscsi specific is it? It seems like it could go
someone more generic.
+void iscsit_release_cmd_direct(struct iscsi_cmd *cmd)
+{
+ iscsit_free_r2ts_from_list(cmd);
+ iscsit_free_all_datain_reqs(cmd);
+
+ kfree(cmd->buf_ptr);
+ kfree(cmd->pdu_list);
+ kfree(cmd->seq_list);
+ kfree(cmd->tmr_req);
+ kfree(cmd->iov_data);
+
+ kmem_cache_free(lio_cmd_cache, cmd);
+}
+
+void __iscsit_release_cmd_to_pool(struct iscsi_cmd *cmd, struct iscsi_session *sess)
+{
+ struct iscsi_conn *conn = cmd->conn;
+
+ iscsit_free_r2ts_from_list(cmd);
+ iscsit_free_all_datain_reqs(cmd);
+
+ kfree(cmd->buf_ptr);
+ kfree(cmd->pdu_list);
+ kfree(cmd->seq_list);
+ kfree(cmd->tmr_req);
+ kfree(cmd->iov_data);
+
+ if (conn) {
+ iscsit_remove_cmd_from_immediate_queue(cmd, conn);
+ iscsit_remove_cmd_from_response_queue(cmd, conn);
+ }
+
+ kmem_cache_free(lio_cmd_cache, cmd);
+}
sess is not used and I could not figure the _to_pool part of the name.
This is not some sort of mistake, right? iscsit_release_cmd_direct and
__iscsit_release_cmd_to_pool look alike except for the conn check
related code. Did you mean to merge those functions?
+
+void iscsit_release_cmd_to_pool(struct iscsi_cmd *cmd)
+{
+ if (!cmd->conn&& !cmd->sess) {
+ iscsit_release_cmd_direct(cmd);
+ } else {
+ __iscsit_release_cmd_to_pool(cmd, (cmd->conn) ?
+ cmd->conn->sess : cmd->sess);
+ }
+}
+
+/*
+ * Routine to pack an ordinary (LINUX) LUN 32-bit number
+ * into an 8-byte LUN structure
+ * (see SAM-2, Section 4.12.3 page 39)
+ * Thanks to UNH for help with this :-).
+ */
+inline u64 iscsit_pack_lun(unsigned int lun)
+{
+ u64 result;
+
+ result = ((lun& 0xff)<< 8); /* LSB of lun into byte 1 big-endian */
+
+ if (0) {
+ /* use flat space addressing method, SAM-2 Section 4.12.4
+ - high-order 2 bits of byte 0 are 01
+ - low-order 6 bits of byte 0 are MSB of the lun
+ - all 8 bits of byte 1 are LSB of the lun
+ - all other bytes (2 thru 7) are 0
+ */
+ result |= 0x40 | ((lun>> 8)& 0x3f);
+ }
+ /* else use peripheral device addressing method, Sam-2 Section 4.12.5
+ - high-order 2 bits of byte 0 are 00
+ - low-order 6 bits of byte 0 are all 0
+ - all 8 bits of byte 1 are the lun
+ - all other bytes (2 thru 7) are 0
+ */
+
+ return cpu_to_le64(result);
+}
Is this int_to_scsilun?
+
+/*
+ * Routine to pack an 8-byte LUN structure into a ordinary (LINUX) 32-bit
+ * LUN number (see SAM-2, Section 4.12.3 page 39)
+ * Thanks to UNH for help with this :-).
+ */
+inline u32 iscsit_unpack_lun(unsigned char *lun_ptr)
+{
+ u32 result, temp;
+
+ result = *(lun_ptr+1); /* LSB of lun from byte 1 big-endian */
+
+ switch (temp = ((*lun_ptr)>>6)) { /* high 2 bits of byte 0 big-endian */
+ case 0: /* peripheral device addressing method, Sam-2 Section 4.12.5
+ - high-order 2 bits of byte 0 are 00
+ - low-order 6 bits of byte 0 are all 0
+ - all 8 bits of byte 1 are the lun
+ - all other bytes (2 thru 7) are 0
+ */
+ if (*lun_ptr != 0) {
+ printk(KERN_ERR "Illegal Byte 0 in LUN peripheral"
+ " device addressing method %u, expected 0\n",
+ *lun_ptr);
+ }
+ break;
+ case 1: /* flat space addressing method, SAM-2 Section 4.12.4
+ - high-order 2 bits of byte 0 are 01
+ - low-order 6 bits of byte 0 are MSB of the lun
+ - all 8 bits of byte 1 are LSB of the lun
+ - all other bytes (2 thru 7) are 0
+ */
+ result += ((*lun_ptr)& 0x3f)<< 8;
+ break;
+ default: /* (extended) logical unit addressing */
+ printk(KERN_ERR "Unimplemented LUN addressing method %u, "
+ "PDA method used instead\n", temp);
+ break;
+ }
+
+ return result;
+}
scsilun_to_int?
+
+int iscsit_check_session_usage_count(struct iscsi_session *sess)
+{
+ spin_lock_bh(&sess->session_usage_lock);
+ if (atomic_read(&sess->session_usage_count)) {
+ atomic_set(&sess->session_waiting_on_uc, 1);
+ spin_unlock_bh(&sess->session_usage_lock);
+ if (in_interrupt())
+ return 2;
+
+ wait_for_completion(&sess->session_waiting_on_uc_comp);
+ return 1;
+ }
+ spin_unlock_bh(&sess->session_usage_lock);
+
+ return 0;
+}
+
+void iscsit_dec_session_usage_count(struct iscsi_session *sess)
+{
+ spin_lock_bh(&sess->session_usage_lock);
+ atomic_dec(&sess->session_usage_count);
+
+ if (!atomic_read(&sess->session_usage_count)&&
+ atomic_read(&sess->session_waiting_on_uc))
+ complete(&sess->session_waiting_on_uc_comp);
+
+ spin_unlock_bh(&sess->session_usage_lock);
+}
+
+void iscsit_inc_session_usage_count(struct iscsi_session *sess)
+{
+ spin_lock_bh(&sess->session_usage_lock);
+ atomic_inc(&sess->session_usage_count);
+ spin_unlock_bh(&sess->session_usage_lock);
+}
It seems strange for the session_usage_count and waiting_on_uc to be
atomic and accessed under the spin lock. I think you normally do one or
the other.
+
+unsigned char *iscsit_ntoa(u32 ip)
+{
+ static unsigned char buf[18];
+
+ memset(buf, 0, 18);
+ sprintf(buf, "%u.%u.%u.%u", ((ip>> 24)& 0xff), ((ip>> 16)& 0xff),
+ ((ip>> 8)& 0xff), (ip& 0xff));
+
+ return buf;
+}
Nothing is using this. Remove.
+
+void iscsit_ntoa2(unsigned char *buf, u32 ip)
+{
+ memset(buf, 0, 18);
+ sprintf(buf, "%u.%u.%u.%u", ((ip>> 24)& 0xff), ((ip>> 16)& 0xff),
+ ((ip>> 8)& 0xff), (ip& 0xff));
+}
I think we have a function like this already.
If not, I think this should be:
sprintf(buf, "%pI4",
What s up with ipv6 btw? That uses %pI6.
+
+#define NS_INT16SZ 2
+#define NS_INADDRSZ 4
+#define NS_IN6ADDRSZ 16
+
+/* const char *
+ * inet_ntop4(src, dst, size)
+ * format an IPv4 address
+ * return:
+ * `dst' (as a const)
+ * notes:
+ * (1) uses no statics
+ * (2) takes a unsigned char* not an in_addr as input
+ * author:
+ * Paul Vixie, 1996.
+ */
+static const char *iscsit_ntop4(
Only used by iscsit_ntop6
+/* const char *
+ * isc_inet_ntop6(src, dst, size)
+ * convert IPv6 binary address into presentation (printable) format
+ * author:
+ * Paul Vixie, 1996.
+ */
+const char *iscsit_ntop6(const unsigned char *src, char *dst, size_t size)
+{
Not used.
+
+/* int
+ * inet_pton4(src, dst)
+ * like inet_aton() but without all the hexadecimal and shorthand.
+ * return:
+ * 1 if `src' is a valid dotted quad, else 0.
+ * notice:
+ * does not touch `dst' unless it's returning 1.
+ * author:
+ * Paul Vixie, 1996.
+ */
+static int iscsit_pton4(const char *src, unsigned char *dst)
+{
Only used by inet_pton6
+
+/* int
+ * inet_pton6(src, dst)
+ * convert presentation level address to network order binary form.
+ * return:
+ * 1 if `src' is a valid [RFC1884 2.2] address, else 0.
+ * notice:
+ * (1) does not touch `dst' unless it's returning 1.
+ * (2) :: in a full address is silently ignored.
+ * credit:
+ * inspired by Mark Andrews.
+ * author:
+ * Paul Vixie, 1996.
+ */
+int iscsit_pton6(const char *src, unsigned char *dst)
+{
+ static const char xdigits_l[] = "0123456789abcdef",
Not used.
I think if you needed these functions then they should go into some
network code. There were not specific to a iscsi target were they.
+
+ return NULL;
+}
+
+void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
+{
+ spin_lock_bh(&conn->conn_usage_lock);
+ if (atomic_read(&conn->conn_usage_count)) {
+ atomic_set(&conn->conn_waiting_on_uc, 1);
+ spin_unlock_bh(&conn->conn_usage_lock);
+
+ wait_for_completion(&conn->conn_waiting_on_uc_comp);
+ return;
+ }
+ spin_unlock_bh(&conn->conn_usage_lock);
+}
+
+void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
+{
+ spin_lock_bh(&conn->conn_usage_lock);
+ atomic_dec(&conn->conn_usage_count);
+
+ if (!atomic_read(&conn->conn_usage_count)&&
+ atomic_read(&conn->conn_waiting_on_uc))
+ complete(&conn->conn_waiting_on_uc_comp);
+
+ spin_unlock_bh(&conn->conn_usage_lock);
+}
+
+void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
+{
+ spin_lock_bh(&conn->conn_usage_lock);
+ atomic_inc(&conn->conn_usage_count);
+ spin_unlock_bh(&conn->conn_usage_lock);
+}
Something about atomics and always being accessed under a lock. I think
this happens in other places too.
Could this also be done with krefs?
+
+int iscsit_check_for_active_network_device(struct iscsi_conn *conn)
+{
+ struct net_device *net_dev;
+
+ if (!conn->net_if) {
+ printk(KERN_ERR "struct iscsi_conn->net_if is NULL for CID:";
+ " %hu\n", conn->cid);
+ return 0;
+ }
+ net_dev = conn->net_if;
+
+ return netif_carrier_ok(net_dev);
+}
+
+static void iscsit_handle_netif_timeout(unsigned long data)
+{
+ struct iscsi_conn *conn = (struct iscsi_conn *) data;
+
+ iscsit_inc_conn_usage_count(conn);
+
+ spin_lock_bh(&conn->netif_lock);
+ if (conn->netif_timer_flags& ISCSI_TF_STOP) {
+ spin_unlock_bh(&conn->netif_lock);
+ iscsit_dec_conn_usage_count(conn);
+ return;
+ }
+ conn->netif_timer_flags&= ~ISCSI_TF_RUNNING;
+
+ if (iscsit_check_for_active_network_device((void *)conn)) {
+ iscsit_start_netif_timer(conn);
+ spin_unlock_bh(&conn->netif_lock);
+ iscsit_dec_conn_usage_count(conn);
+ return;
+ }
+
+ printk(KERN_ERR "Detected PHY loss on Network Interface: %s for iSCSI"
+ " CID: %hu on SID: %u\n", conn->net_dev, conn->cid,
+ conn->sess->sid);
+
+ spin_unlock_bh(&conn->netif_lock);
+
+ iscsit_cause_connection_reinstatement(conn, 0);
+ iscsit_dec_conn_usage_count(conn);
+}
I think instead of polling the device you can use
register_netdevice_notifier. See fcoe.c for an example.
+
+static inline int iscsit_do_rx_data(
+ struct iscsi_conn *conn,
+ struct iscsi_data_count *count)
+{
+
+ while (total_rx< data) {
+ oldfs = get_fs();
+ set_fs(get_ds());
+
+ conn->sock->sk->sk_allocation = GFP_ATOMIC;
I do not think you need GFP_ATOMIC. If you cannot sleep then I think you
are in trouble below, because you pass in MSG_WAITALL.
I think since this is the target side you can use GFP_KERNEL. Target
mode should not have the same allocation swinging around on you
dependency problem like a initiator does, does it?
If it does at least use GFP_NOIO (I think iscsi_tcp.c should be using
GFP_NOIO and not GFP_ATOMIC).
And I think we are supposed to be using kernel_recvmsg. It does the
get/set_ds stuff for you.
+ rx_loop = sock_recvmsg(conn->sock,&msg,
+ (data - total_rx), MSG_WAITALL);
+
+static inline int iscsit_do_tx_data(
+ struct iscsi_conn *conn,
+ struct iscsi_data_count *count)
+{
+
+ while (total_tx< data) {
+ oldfs = get_fs();
+ set_fs(get_ds());
+
+ conn->sock->sk->sk_allocation = GFP_ATOMIC;
Same comment as the recv side. I think you can also move this and set it
in one place.
And I think we are supposed to be using kernel_sendmsg. That will also
do the get/set_fs stuff for you.
+ tx_loop = sock_sendmsg(conn->sock,&msg, (data - total_tx));
+
+ set_fs(oldfs);
+
+extern int iscsit_build_sendtargets_response(struct iscsi_cmd *cmd)
+{
+ char *ip, *payload = NULL;
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_portal_group *tpg;
+ struct iscsi_tiqn *tiqn;
+ struct iscsi_tpg_np *tpg_np;
+ int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
+ unsigned char buf[256];
+ unsigned char buf_ipv4[IPV4_BUF_SIZE];
+
+ buffer_len = (conn->conn_ops->MaxRecvDataSegmentLength> 32768) ?
+ 32768 : conn->conn_ops->MaxRecvDataSegmentLength;
+
+ payload = kzalloc(buffer_len, GFP_KERNEL);
+ if (!payload) {
+ printk(KERN_ERR "Unable to allocate memory for sendtargets"
+ " response.\n");
+ return -1;
+ }
+
+ spin_lock(&tiqn_lock);
+ list_for_each_entry(tiqn,&g_tiqn_list, tiqn_list) {
+ memset(buf, 0, 256);
+
+ len = sprintf(buf, "TargetName=%s", tiqn->tiqn);
+ len += 1;
+
+ if ((len + payload_len)> buffer_len) {
+ spin_unlock(&tiqn->tiqn_tpg_lock);
+ end_of_buf = 1;
+ goto eob;
+ }
+ memcpy((void *)payload + payload_len, buf, len);
+ payload_len += len;
+
+ spin_lock(&tiqn->tiqn_tpg_lock);
+ list_for_each_entry(tpg,&tiqn->tiqn_tpg_list, tpg_list) {
+
+ spin_lock(&tpg->tpg_state_lock);
+ if ((tpg->tpg_state == TPG_STATE_FREE) ||
+ (tpg->tpg_state == TPG_STATE_INACTIVE)) {
+ spin_unlock(&tpg->tpg_state_lock);
+ continue;
+ }
+ spin_unlock(&tpg->tpg_state_lock);
+
+ spin_lock(&tpg->tpg_np_lock);
+ list_for_each_entry(tpg_np,&tpg->tpg_gnp_list,
+ tpg_np_list) {
+ memset(buf, 0, 256);
+
+ if (tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) {
+ ip =&tpg_np->tpg_np->np_ipv6[0];
Is ip supposed to be a string with the ip address in it? If so is that
right? Is np_ipv6 a string with the ip address in human readable format,
but below np_ipv4 is the integer representation then you convert it.
+ } else {
+ memset(buf_ipv4, 0, IPV4_BUF_SIZE);
+ iscsit_ntoa2(buf_ipv4,
+ tpg_np->tpg_np->np_ipv4);
+ ip =&buf_ipv4[0];
+ }
+
+ len = sprintf(buf, "TargetAddress="
+ "%s%s%s:%hu,%hu",
+ (tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) ?
+ "[" : "", ip,
+ (tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) ?
+ "]" : "", tpg_np->tpg_np->np_port,
+ tpg->tpgt);
+ len += 1;
+
+ if ((len + payload_len)> buffer_len) {
+ spin_unlock(&tpg->tpg_np_lock);
+ spin_unlock(&tiqn->tiqn_tpg_lock);
+ end_of_buf = 1;
+ goto eob;
+ }
+
+ memcpy((void *)payload + payload_len, buf, len);
+ payload_len += len;
+ }
+ spin_unlock(&tpg->tpg_np_lock);
+ }
+ spin_unlock(&tiqn->tiqn_tpg_lock);
+eob:
+ if (end_of_buf)
+ break;
+ }
+ spin_unlock(&tiqn_lock);
+
+ cmd->buf_ptr = payload;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/