[PATCH 13/21] uas: Drop all references to a scsi_cmnd once it has been aborted

Hans de Goede
2014-09-10T11:47:17Z

Do not keep references around to a cmnd which is under error handling.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/usb/storage/uas.c | 47 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 1fdcfad..75ce40c 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -254,12 +254,11 @@ static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
lockdep_assert_held(&devinfo->lock);
if (cmdinfo->state & (COMMAND_INFLIGHT |
DATA_IN_URB_INFLIGHT |
- DATA_OUT_URB_INFLIGHT))
+ DATA_OUT_URB_INFLIGHT |
+ COMMAND_ABORTED))
return -EBUSY;
WARN_ON_ONCE(cmdinfo->state & COMMAND_COMPLETED);
cmdinfo->state |= COMMAND_COMPLETED;
- if (cmdinfo->state & COMMAND_ABORTED)
- scmd_printk(KERN_INFO, cmnd, "abort completed\n");
devinfo->cmnd[uas_get_tag(cmnd) - 1] = NULL;
cmnd->scsi_done(cmnd);
return 0;
@@ -700,6 +699,47 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,

static DEF_SCSI_QCMD(uas_queuecommand)

+/*
+ * For now we do not support actually sending an abort to the device, so
+ * this eh always fails. Still we must define it to make sure that we've
+ * dropped all references to the cmnd in question once this function exits.
+ */
+static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
+{
+ struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+ struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
+ struct urb *data_in_urb = NULL;
+ struct urb *data_out_urb = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&devinfo->lock, flags);
+
+ uas_log_cmd_state(cmnd, __func__);
+
+ /* Ensure that try_complete does not call scsi_done */
+ cmdinfo->state |= COMMAND_ABORTED;
+
+ /* Drop all refs to this cmnd, kill data urbs to break their ref */
+ devinfo->cmnd[uas_get_tag(cmnd) - 1] = NULL;
+ if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
+ data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
+ if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
+ data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
+
+ spin_unlock_irqrestore(&devinfo->lock, flags);
+
+ if (data_in_urb) {
+ usb_kill_urb(data_in_urb);
+ usb_put_urb(data_in_urb);
+ }
+ if (data_out_urb) {
+ usb_kill_urb(data_out_urb);
+ usb_put_urb(data_out_urb);
+ }
+
+ return FAILED;
+}
+
static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
{
struct scsi_device *sdev = cmnd->device;
@@ -781,6 +821,7 @@ static struct scsi_host_template uas_host_template = {
.queuecommand = uas_queuecommand,
.slave_alloc = uas_slave_alloc,
.slave_configure = uas_slave_configure,
+ .eh_abort_handler = uas_eh_abort_handler,
.eh_bus_reset_handler = uas_eh_bus_reset_handler,
.can_queue = 65536, /* Is there a limit on the _host_ ? */
.this_id = -1,
--
2.1.0