[BLOCK] update SCSI to use new blk_ordered for barriers

All ordered request related stuff delegated to HLD.  Midlayer
now doens't deal with ordered setting or prepare_flush
callback.  sd.c updated to deal with blk_queue_ordered
setting.  Currently, ordered tag isn't used as SCSI midlayer
cannot guarantee request ordering.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 5b9c2c5..66783c8 100644 (file)
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -347,17 +347,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
        shost->cmd_per_lun = sht->cmd_per_lun;
        shost->unchecked_isa_dma = sht->unchecked_isa_dma;
        shost->use_clustering = sht->use_clustering;
-       shost->ordered_flush = sht->ordered_flush;
        shost->ordered_tag = sht->ordered_tag;
 
-       /*
-        * hosts/devices that do queueing must support ordered tags
-        */
-       if (shost->can_queue > 1 && shost->ordered_flush) {
-               printk(KERN_ERR "scsi: ordered flushes don't support queueing\n");
-               shost->ordered_flush = 0;
-       }
-
        if (sht->max_host_blocked)
                shost->max_host_blocked = sht->max_host_blocked;
        else

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 53551f1..7a38b10 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -932,9 +932,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
        int sense_valid = 0;
        int sense_deferred = 0;
 
-       if (blk_complete_barrier_rq(q, req, good_bytes >> 9))
-               return;
-
        /*
         * Free up any indirection buffers we allocated for DMA purposes. 
         * For the case of a READ, we need to copy the data out of the
@@ -1199,38 +1196,6 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
        return BLKPREP_KILL;
 }
 
-static int scsi_prepare_flush_fn(request_queue_t *q, struct request *rq)
-{
-       struct scsi_device *sdev = q->queuedata;
-       struct scsi_driver *drv;
-
-       if (sdev->sdev_state == SDEV_RUNNING) {
-               drv = *(struct scsi_driver **) rq->rq_disk->private_data;
-
-               if (drv->prepare_flush)
-                       return drv->prepare_flush(q, rq);
-       }
-
-       return 0;
-}
-
-static void scsi_end_flush_fn(request_queue_t *q, struct request *rq)
-{
-       struct scsi_device *sdev = q->queuedata;
-       struct request *flush_rq = rq->end_io_data;
-       struct scsi_driver *drv;
-
-       if (flush_rq->errors) {
-               printk("scsi: barrier error, disabling flush support\n");
-               blk_queue_ordered(q, QUEUE_ORDERED_NONE);
-       }
-
-       if (sdev->sdev_state == SDEV_RUNNING) {
-               drv = *(struct scsi_driver **) rq->rq_disk->private_data;
-               drv->end_flush(q, rq);
-       }
-}
-
 static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
                               sector_t *error_sector)
 {
@@ -1703,17 +1668,6 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
        blk_queue_segment_boundary(q, shost->dma_boundary);
        blk_queue_issue_flush_fn(q, scsi_issue_flush_fn);
 
-       /*
-        * ordered tags are superior to flush ordering
-        */
-       if (shost->ordered_tag)
-               blk_queue_ordered(q, QUEUE_ORDERED_TAG);
-       else if (shost->ordered_flush) {
-               blk_queue_ordered(q, QUEUE_ORDERED_FLUSH);
-               q->prepare_flush_fn = scsi_prepare_flush_fn;
-               q->end_flush_fn = scsi_end_flush_fn;
-       }
-
        if (!shost->use_clustering)
                clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
        return q;

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d651150..2eefc9e 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -121,8 +121,7 @@ static void sd_shutdown(struct device *dev);
 static void sd_rescan(struct device *);
 static int sd_init_command(struct scsi_cmnd *);
 static int sd_issue_flush(struct device *, sector_t *);
-static void sd_end_flush(request_queue_t *, struct request *);
-static int sd_prepare_flush(request_queue_t *, struct request *);
+static void sd_prepare_flush(request_queue_t *, struct request *);
 static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
                             unsigned char *buffer);
 
@@ -137,8 +136,6 @@ static struct scsi_driver sd_template = {
        .rescan                 = sd_rescan,
        .init_command           = sd_init_command,
        .issue_flush            = sd_issue_flush,
-       .prepare_flush          = sd_prepare_flush,
-       .end_flush              = sd_end_flush,
 };
 
 /*
@@ -729,42 +726,13 @@ static int sd_issue_flush(struct device *dev, sector_t *error_sector)
        return ret;
 }
 
-static void sd_end_flush(request_queue_t *q, struct request *flush_rq)
+static void sd_prepare_flush(request_queue_t *q, struct request *rq)
 {
-       struct request *rq = flush_rq->end_io_data;
-       struct scsi_cmnd *cmd = rq->special;
-       unsigned int bytes = rq->hard_nr_sectors << 9;
-
-       if (!flush_rq->errors) {
-               spin_unlock(q->queue_lock);
-               scsi_io_completion(cmd, bytes, 0);
-               spin_lock(q->queue_lock);
-       } else if (blk_barrier_postflush(rq)) {
-               spin_unlock(q->queue_lock);
-               scsi_io_completion(cmd, 0, bytes);
-               spin_lock(q->queue_lock);
-       } else {
-               /*
-                * force journal abort of barriers
-                */
-               end_that_request_first(rq, -EOPNOTSUPP, rq->hard_nr_sectors);
-               end_that_request_last(rq, -EOPNOTSUPP);
-       }
-}
-
-static int sd_prepare_flush(request_queue_t *q, struct request *rq)
-{
-       struct scsi_device *sdev = q->queuedata;
-       struct scsi_disk *sdkp = dev_get_drvdata(&sdev->sdev_gendev);
-
-       if (!sdkp || !sdkp->WCE)
-               return 0;
-
        memset(rq->cmd, 0, sizeof(rq->cmd));
-       rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER;
+       rq->flags |= REQ_BLOCK_PC;
        rq->timeout = SD_TIMEOUT;
        rq->cmd[0] = SYNCHRONIZE_CACHE;
-       return 1;
+       rq->cmd_len = 10;
 }
 
 static void sd_rescan(struct device *dev)
@@ -1462,6 +1430,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
        struct scsi_disk *sdkp = scsi_disk(disk);
        struct scsi_device *sdp = sdkp->device;
        unsigned char *buffer;
+       unsigned ordered;
 
        SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name));
 
@@ -1498,7 +1467,20 @@ static int sd_revalidate_disk(struct gendisk *disk)
                sd_read_write_protect_flag(sdkp, disk->disk_name, buffer);
                sd_read_cache_type(sdkp, disk->disk_name, buffer);
        }
-               
+
+       /*
+        * We now have all cache related info, determine how we deal
+        * with ordered requests.  Note that as the current SCSI
+        * dispatch function can alter request order, we cannot use
+        * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
+        */
+       if (sdkp->WCE)
+               ordered = QUEUE_ORDERED_DRAIN_FLUSH;
+       else
+               ordered = QUEUE_ORDERED_DRAIN;
+
+       blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
+
        set_capacity(disk, sdkp->capacity);
        kfree(buffer);
 
@@ -1598,6 +1580,7 @@ static int sd_probe(struct device *dev)
        strcpy(gd->devfs_name, sdp->devfs_name);
 
        gd->private_data = &sdkp->driver;
+       gd->queue = sdkp->device->request_queue;
 
        sd_revalidate_disk(gd);
 
@@ -1605,7 +1588,6 @@ static int sd_probe(struct device *dev)
        gd->flags = GENHD_FL_DRIVERFS;
        if (sdp->removable)
                gd->flags |= GENHD_FL_REMOVABLE;
-       gd->queue = sdkp->device->request_queue;
 
        dev_set_drvdata(dev, sdkp);
        add_disk(gd);

diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
index 850dfa8..02e26c1 100644 (file)
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -15,7 +15,6 @@ struct scsi_driver {
        void (*rescan)(struct device *);
        int (*issue_flush)(struct device *, sector_t *);
        int (*prepare_flush)(struct request_queue *, struct request *);
-       void (*end_flush)(struct request_queue *, struct request *);
 };
 #define to_scsi_driver(drv) \
        container_of((drv), struct scsi_driver, gendrv)

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 6cbb198..25f637b 100644 (file)
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -392,7 +392,6 @@ struct scsi_host_template {
        /*
         * ordered write support
         */
-       unsigned ordered_flush:1;
        unsigned ordered_tag:1;
 
        /*