target: Add return for se_cmd->transport_complete_callback

This patch adds a sense_reason_t return to ->transport_complete_callback(),
and updates target_complete_ok_work() to invoke the call if necessary to
transport_send_check_condition_and_sense() during the failure case.

Also update xdreadwrite_callback() to use this return value.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 8a46277..be5234a 100644 (file)
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -280,13 +280,13 @@ sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *o
        return 0;
 }
 
-static void xdreadwrite_callback(struct se_cmd *cmd)
+static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
 {
        unsigned char *buf, *addr;
        struct scatterlist *sg;
        unsigned int offset;
-       int i;
-       int count;
+       sense_reason_t ret = TCM_NO_SENSE;
+       int i, count;
        /*
         * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
         *
@@ -301,7 +301,7 @@ static void xdreadwrite_callback(struct se_cmd *cmd)
        buf = kmalloc(cmd->data_length, GFP_KERNEL);
        if (!buf) {
                pr_err("Unable to allocate xor_callback buf\n");
-               return;
+               return TCM_OUT_OF_RESOURCES;
        }
        /*
         * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
@@ -320,8 +320,10 @@ static void xdreadwrite_callback(struct se_cmd *cmd)
        offset = 0;
        for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
                addr = kmap_atomic(sg_page(sg));
-               if (!addr)
+               if (!addr) {
+                       ret = TCM_OUT_OF_RESOURCES;
                        goto out;
+               }
 
                for (i = 0; i < sg->length; i++)
                        *(addr + sg->offset + i) ^= *(buf + offset + i);
@@ -332,6 +334,7 @@ static void xdreadwrite_callback(struct se_cmd *cmd)
 
 out:
        kfree(buf);
+       return ret;
 }
 
 sense_reason_t

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 98ec711..53d1d75 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1904,10 +1904,24 @@ static void target_complete_ok_work(struct work_struct *work)
        }
        /*
         * Check for a callback, used by amongst other things
-        * XDWRITE_READ_10 emulation.
+        * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
         */
-       if (cmd->transport_complete_callback)
-               cmd->transport_complete_callback(cmd);
+       if (cmd->transport_complete_callback) {
+               sense_reason_t rc;
+
+               rc = cmd->transport_complete_callback(cmd);
+               if (!rc)
+                       return;
+
+               ret = transport_send_check_condition_and_sense(cmd,
+                                       rc, 0);
+               if (ret == -EAGAIN || ret == -ENOMEM)
+                       goto queue_full;
+
+               transport_lun_remove_cmd(cmd);
+               transport_cmd_check_stop_to_fabric(cmd);
+               return;
+       }
 
        switch (cmd->data_direction) {
        case DMA_FROM_DEVICE:

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index bd55acd..6892b33 100644 (file)
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -447,7 +447,7 @@ struct se_cmd {
        struct kref             cmd_kref;
        struct target_core_fabric_ops *se_tfo;
        sense_reason_t          (*execute_cmd)(struct se_cmd *);
-       void (*transport_complete_callback)(struct se_cmd *);
+       sense_reason_t (*transport_complete_callback)(struct se_cmd *);
 
        unsigned char           *t_task_cdb;
        unsigned char           __t_task_cdb[TCM_MAX_COMMAND_SIZE];