[PATCH v3 1/5] virtio-scsi: redo allocation of target data

From: Paolo Bonzini
Date: Tue Feb 12 2013 - 08:06:59 EST


virtio_scsi_target_state is now empty, but we will find new uses
for it in the next few patches. However, dropping the sglist lets
us turn the array-of-pointers into a simple array, which simplifies
the allocation.

However, we do not leave the virtio_scsi_target_state structs in the
flexible array member at the end of struct virtio_scsi, because
we will place the virtqueues there in the next patches.

Cc: linux-scsi@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
drivers/scsi/virtio_scsi.c | 39 ++++++++++++---------------------------
1 files changed, 12 insertions(+), 27 deletions(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 8b90c17..3f15568 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -74,7 +74,7 @@ struct virtio_scsi {
/* Get some buffers ready for event vq */
struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];

- struct virtio_scsi_target_state *tgt[];
+ struct virtio_scsi_target_state *tgt;
};

static struct kmem_cache *virtscsi_cmd_cache;
@@ -574,19 +574,9 @@ static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
virtscsi_vq->vq = vq;
}

-static struct virtio_scsi_target_state *virtscsi_alloc_tgt(
- struct virtio_device *vdev, int sg_elems)
+static void virtscsi_init_tgt(struct virtio_scsi_target_state *tgt)
{
- struct virtio_scsi_target_state *tgt;
- gfp_t gfp_mask = GFP_KERNEL;
-
- /* We need extra sg elements at head and tail. */
- tgt = kmalloc(sizeof(*tgt), gfp_mask);
- if (!tgt)
- return NULL;
-
spin_lock_init(&tgt->tgt_lock);
- return tgt;
}

static void virtscsi_scan(struct virtio_device *vdev)
@@ -600,16 +590,12 @@ static void virtscsi_remove_vqs(struct virtio_device *vdev)
{
struct Scsi_Host *sh = virtio_scsi_host(vdev);
struct virtio_scsi *vscsi = shost_priv(sh);
- u32 i, num_targets;

/* Stop all the virtqueues. */
vdev->config->reset(vdev);

- num_targets = sh->max_id;
- for (i = 0; i < num_targets; i++) {
- kfree(vscsi->tgt[i]);
- vscsi->tgt[i] = NULL;
- }
+ kfree(vscsi->tgt);
+ vscsi->tgt = NULL;

vdev->config->del_vqs(vdev);
}
@@ -650,13 +636,14 @@ static int virtscsi_init(struct virtio_device *vdev,
/* We need to know how many segments before we allocate. */
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;

- for (i = 0; i < num_targets; i++) {
- vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
- if (!vscsi->tgt[i]) {
- err = -ENOMEM;
- goto out;
- }
+ vscsi->tgt = kmalloc(num_targets * sizeof(vscsi->tgt[0]), GFP_KERNEL);
+ if (!vscsi->tgt) {
+ err = -ENOMEM;
+ goto out;
}
+ for (i = 0; i < num_targets; i++)
+ virtscsi_init_tgt(&vscsi->tgt[i]);
+
err = 0;

out:
@@ -675,9 +662,7 @@ static int virtscsi_probe(struct virtio_device *vdev)

/* Allocate memory and link the structs together. */
num_targets = virtscsi_config_get(vdev, max_target) + 1;
- shost = scsi_host_alloc(&virtscsi_host_template,
- sizeof(*vscsi)
- + num_targets * sizeof(struct virtio_scsi_target_state));
+ shost = scsi_host_alloc(&virtscsi_host_template, sizeof(*vscsi));

if (!shost)
return -ENOMEM;
--
1.7.1


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