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SubjectRe: [RFC-v4 11/12] iscsi-target: Add misc utility and debug logic
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;


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