[SCSI] iscsi_tcp: rewrite recv path

Rewrite recv path. Fixes:
- data digest processing and error handling.
- ahs support.

Some fixups by Mike Christie

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 41 insertions, 25 deletions

diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index 7eba44df0a7f..f1c541151100 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -24,13 +24,6 @@
 
 #include <scsi/libiscsi.h>
 
-/* Socket's Receive state machine */
-#define IN_PROGRESS_WAIT_HEADER         0x0
-#define IN_PROGRESS_HEADER_GATHER       0x1
-#define IN_PROGRESS_DATA_RECV           0x2
-#define IN_PROGRESS_DDIGEST_RECV        0x3
-#define IN_PROGRESS_PAD_RECV            0x4
-
 /* xmit state machine */
 #define XMSTATE_IDLE                    0x0
 #define XMSTATE_CMD_HDR_INIT            0x1
@@ -54,41 +47,64 @@
 
 struct crypto_hash;
 struct socket;
+struct iscsi_tcp_conn;
+struct iscsi_chunk;
+
+typedef int iscsi_chunk_done_fn_t(struct iscsi_tcp_conn *,
+                                  struct iscsi_chunk *);
+
+struct iscsi_chunk {
+        unsigned char           *data;
+        unsigned int            size;
+        unsigned int            copied;
+        unsigned int            total_size;
+        unsigned int            total_copied;
+
+        struct hash_desc        *hash;
+        unsigned char           recv_digest[ISCSI_DIGEST_SIZE];
+        unsigned char           digest[ISCSI_DIGEST_SIZE];
+        unsigned int            digest_len;
+
+        struct scatterlist      *sg;
+        void                    *sg_mapped;
+        unsigned int            sg_offset;
+        unsigned int            sg_index;
+        unsigned int            sg_count;
+
+        iscsi_chunk_done_fn_t   *done;
+};
 
 /* Socket connection recieve helper */
 struct iscsi_tcp_recv {
         struct iscsi_hdr        *hdr;
-        struct sk_buff          *skb;
-        int                     offset;
-        int                     len;
-        int                     hdr_offset;
-        int                     copy;
-        int                     copied;
-        int                     padding;
-        struct iscsi_cmd_task   *ctask;         /* current cmd in progress */
+        struct iscsi_chunk      chunk;
+
+        /* Allocate buffer for BHS + AHS */
+        uint32_t                hdr_buf[64];
 
         /* copied and flipped values */
         int                     datalen;
-        int                     datadgst;
-        char                    zero_copy_hdr;
+};
+
+/* Socket connection send helper */
+struct iscsi_tcp_send {
+        struct iscsi_hdr        *hdr;
+        struct iscsi_chunk      chunk;
+        struct iscsi_chunk      data_chunk;
+
+        /* Allocate buffer for BHS + AHS */
+        uint32_t                hdr_buf[64];
 };
 
 struct iscsi_tcp_conn {
         struct iscsi_conn       *iscsi_conn;
         struct socket           *sock;
-        struct iscsi_hdr        hdr;            /* header placeholder */
-        char                    hdrext[4*sizeof(__u16) +
-                                    sizeof(__u32)];
-        int                     data_copied;
         int                     stop_stage;     /* conn_stop() flag: *
                                                  * stop to recover,  *
                                                  * stop to terminate */
-        /* iSCSI connection-wide sequencing */
-        int                     hdr_size;       /* PDU header size */
-
         /* control data */
         struct iscsi_tcp_recv   in;             /* TCP receive context */
-        int                     in_progress;    /* connection state machine */
+        struct iscsi_tcp_send   out;            /* TCP send context */
 
         /* old values for socket callbacks */
         void                    (*old_data_ready)(struct sock *, int);