2008-03-07 18:27:32

by Elias Oltmanns

[permalink] [raw]
Subject: [PATCH 3/4] disk-protect: Add a REQ_TYPE_LINUX_BLOCK request handler to libata

Defines a generic handler to be used as the lb_request_fn() callback for
libata managed hosts. Support for REQ_LB_OP_FREEZE and REQ_LB_OP_THAW is
included as well.

Signed-off-by: Elias Oltmanns <[email protected]>
---

drivers/ata/ahci.c | 1 +
drivers/ata/ata_piix.c | 1 +
drivers/ata/libata-scsi.c | 53 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/blkdev.h | 2 ++
include/linux/libata.h | 1 +
5 files changed, 58 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 54f38c2..324c4fa 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -273,6 +273,7 @@ static struct scsi_host_template ahci_sht = {
.name = DRV_NAME,
.ioctl = ata_scsi_ioctl,
.queuecommand = ata_scsi_queuecmd,
+ .lb_request_fn = ata_scsi_lb_request_fn,
.change_queue_depth = ata_scsi_change_queue_depth,
.can_queue = AHCI_MAX_CMDS - 1,
.this_id = ATA_SHT_THIS_ID,
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index b406b39..c2b7ad7 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -283,6 +283,7 @@ static struct scsi_host_template piix_sht = {
.name = DRV_NAME,
.ioctl = ata_scsi_ioctl,
.queuecommand = ata_scsi_queuecmd,
+ .lb_request_fn = ata_scsi_lb_request_fn,
.can_queue = ATA_DEF_QUEUE,
.this_id = ATA_SHT_THIS_ID,
.sg_tablesize = LIBATA_MAX_PRD,
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d0fd762..df25aa4 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3123,6 +3123,59 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd,
}
}

+/**
+ * ata_scsi_lb_request_fn - process block request for libata-managed device
+ * @req: REQ_TYPE_LINUX_BLOCK request to be processed
+ *
+ * This function is the default handler for REQ_TYPE_LINUX_BLOCK
+ * requests in libata.
+ *
+ * LOCKING:
+ * Releases queue lock, and obtains host lock.
+ *
+ * RETURNS:
+ * SUCCESS if opcode is known to us, FAILED otherwise.
+ */
+
+int ata_scsi_lb_request_fn(struct request *req)
+{
+ struct request_queue *q = req->q;
+ struct scsi_device *sdev = q->queuedata;
+ struct Scsi_Host *shost = sdev->host;
+ struct ata_port *ap = ata_shost_to_port(shost);
+ struct ata_device *dev;
+ int rc = SUCCESS;
+
+ spin_unlock(q->queue_lock);
+ spin_lock(ap->lock);
+
+ dev = ata_scsi_find_dev(ap, sdev);
+ if (unlikely(!dev)) {
+ req->errors = -ENXIO;
+ goto out;
+ }
+
+ switch (req->cmd[0]) {
+ case REQ_LB_OP_FREEZE:
+ ata_scsi_protect_dev(dev);
+ break;
+
+ case REQ_LB_OP_THAW:
+ ata_scsi_unprotect_dev(dev);
+ break;
+
+ default:
+ rc = FAILED;
+ goto out;
+ }
+
+out:
+ spin_unlock(ap->lock);
+ spin_lock(q->queue_lock);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ata_scsi_lb_request_fn);
+
int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
{
int i, rc;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5955b57..1854a69 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -164,6 +164,8 @@ enum {
*/
REQ_LB_OP_EJECT = 0x40, /* eject request */
REQ_LB_OP_FLUSH = 0x41, /* flush device */
+ REQ_LB_OP_FREEZE = 0x42, /* freeze queue (protect device) */
+ REQ_LB_OP_THAW = 0x3, /* thaw queue */
};

/*
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2db23c3..4e97964 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -809,6 +809,7 @@ extern void ata_host_init(struct ata_host *, struct device *,
extern int ata_scsi_detect(struct scsi_host_template *sht);
extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
+extern int ata_scsi_lb_request_fn(struct request *req);
extern void ata_sas_port_destroy(struct ata_port *);
extern struct ata_port *ata_sas_port_alloc(struct ata_host *,
struct ata_port_info *, struct Scsi_Host *);


2008-03-15 12:42:44

by Pavel Machek

[permalink] [raw]
Subject: Re: [PATCH 3/4] disk-protect: Add a REQ_TYPE_LINUX_BLOCK request handler to libata

On Fri 2008-03-07 19:26:14, Elias Oltmanns wrote:
> Defines a generic handler to be used as the lb_request_fn() callback for
> libata managed hosts. Support for REQ_LB_OP_FREEZE and REQ_LB_OP_THAW is
> included as well.

> Signed-off-by: Elias Oltmanns <[email protected]>

Both this and previous patch look ok to me -- but I'm not ATA
person...

It would be nice to get them in - thinkpad x42 kills few disks a year
when running w/o active protection.

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html