USB: uas: add locking

Add spinlock to protect uas data structures.

[ v2: s/GFP_NOIO/GFP_ATOMIC/, better don't sleep when holding a spinlock ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 44 insertions, 7 deletions

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index df1d72e4693..15789097edd 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -50,6 +50,7 @@ struct uas_dev_info {
         unsigned use_streams:1;
         unsigned uas_sense_old:1;
         struct scsi_cmnd *cmnd;
+        spinlock_t lock;
 };
 
 enum {
@@ -91,6 +92,7 @@ static void uas_do_work(struct work_struct *work)
         struct uas_cmd_info *cmdinfo;
         struct uas_cmd_info *temp;
         struct list_head list;
+        unsigned long flags;
         int err;
 
         spin_lock_irq(&uas_work_lock);
@@ -101,7 +103,10 @@ static void uas_do_work(struct work_struct *work)
                 struct scsi_pointer *scp = (void *)cmdinfo;
                 struct scsi_cmnd *cmnd = container_of(scp,
                                                         struct scsi_cmnd, SCp);
-                err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_NOIO);
+                struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
+                spin_lock_irqsave(&devinfo->lock, flags);
+                err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
+                spin_unlock_irqrestore(&devinfo->lock, flags);
                 if (err) {
                         list_del(&cmdinfo->list);
                         spin_lock_irq(&uas_work_lock);
@@ -182,7 +187,9 @@ static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *caller)
 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
 {
         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+        struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 
+        WARN_ON(!spin_is_locked(&devinfo->lock));
         if (cmdinfo->state & (COMMAND_INFLIGHT |
                               DATA_IN_URB_INFLIGHT |
                               DATA_OUT_URB_INFLIGHT))
@@ -222,6 +229,7 @@ static void uas_stat_cmplt(struct urb *urb)
         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
         struct scsi_cmnd *cmnd;
         struct uas_cmd_info *cmdinfo;
+        unsigned long flags;
         u16 tag;
 
         if (urb->status) {
@@ -235,6 +243,7 @@ static void uas_stat_cmplt(struct urb *urb)
                 return;
         }
 
+        spin_lock_irqsave(&devinfo->lock, flags);
         tag = be16_to_cpup(&iu->tag) - 1;
         if (tag == 0)
                 cmnd = devinfo->cmnd;
@@ -243,6 +252,7 @@ static void uas_stat_cmplt(struct urb *urb)
         if (!cmnd) {
                 if (iu->iu_id != IU_ID_RESPONSE) {
                         usb_free_urb(urb);
+                        spin_unlock_irqrestore(&devinfo->lock, flags);
                         return;
                 }
         } else {
@@ -262,10 +272,16 @@ static void uas_stat_cmplt(struct urb *urb)
                         uas_sense(urb, cmnd);
                 if (cmnd->result != 0) {
                         /* cancel data transfers on error */
-                        if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
+                        if (cmdinfo->state & DATA_IN_URB_INFLIGHT) {
+                                spin_unlock_irqrestore(&devinfo->lock, flags);
                                 usb_unlink_urb(cmdinfo->data_in_urb);
-                        if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
+                                spin_lock_irqsave(&devinfo->lock, flags);
+                        }
+                        if (cmdinfo->state & DATA_OUT_URB_INFLIGHT) {
+                                spin_unlock_irqrestore(&devinfo->lock, flags);
                                 usb_unlink_urb(cmdinfo->data_out_urb);
+                                spin_lock_irqsave(&devinfo->lock, flags);
+                        }
                 }
                 cmdinfo->state &= ~COMMAND_INFLIGHT;
                 uas_try_complete(cmnd, __func__);
@@ -285,14 +301,18 @@ static void uas_stat_cmplt(struct urb *urb)
                         "Bogus IU (%d) received on status pipe\n", iu->iu_id);
         }
         usb_free_urb(urb);
+        spin_unlock_irqrestore(&devinfo->lock, flags);
 }
 
 static void uas_data_cmplt(struct urb *urb)
 {
         struct scsi_cmnd *cmnd = urb->context;
         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+        struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
         struct scsi_data_buffer *sdb = NULL;
+        unsigned long flags;
 
+        spin_lock_irqsave(&devinfo->lock, flags);
         if (cmdinfo->data_in_urb == urb) {
                 sdb = scsi_in(cmnd);
                 cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
@@ -308,6 +328,7 @@ static void uas_data_cmplt(struct urb *urb)
                 sdb->resid = sdb->length - urb->actual_length;
         }
         uas_try_complete(cmnd, __func__);
+        spin_unlock_irqrestore(&devinfo->lock, flags);
 }
 
 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
@@ -474,6 +495,7 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
         int err;
 
+        WARN_ON(!spin_is_locked(&devinfo->lock));
         if (cmdinfo->state & SUBMIT_STATUS_URB) {
                 err = uas_submit_sense_urb(cmnd->device->host, gfp,
                                            cmdinfo->stream);
@@ -554,12 +576,16 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
         struct scsi_device *sdev = cmnd->device;
         struct uas_dev_info *devinfo = sdev->hostdata;
         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+        unsigned long flags;
         int err;
 
         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 
-        if (devinfo->cmnd)
+        spin_lock_irqsave(&devinfo->lock, flags);
+        if (devinfo->cmnd) {
+                spin_unlock_irqrestore(&devinfo->lock, flags);
                 return SCSI_MLQUEUE_DEVICE_BUSY;
+        }
 
         if (blk_rq_tagged(cmnd->request)) {
                 cmdinfo->stream = cmnd->request->tag + 2;
@@ -594,6 +620,7 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
         if (err) {
                 /* If we did nothing, give up now */
                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
+                        spin_unlock_irqrestore(&devinfo->lock, flags);
                         return SCSI_MLQUEUE_DEVICE_BUSY;
                 }
                 spin_lock(&uas_work_lock);
@@ -602,6 +629,7 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
                 schedule_work(&uas_work);
         }
 
+        spin_unlock_irqrestore(&devinfo->lock, flags);
         return 0;
 }
 
@@ -613,21 +641,25 @@ static int uas_eh_task_mgmt(struct scsi_cmnd *cmnd,
         struct Scsi_Host *shost = cmnd->device->host;
         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
         u16 tag = devinfo->qdepth - 1;
+        unsigned long flags;
 
+        spin_lock_irqsave(&devinfo->lock, flags);
         memset(&devinfo->response, 0, sizeof(devinfo->response));
-        if (uas_submit_sense_urb(shost, GFP_NOIO, tag)) {
+        if (uas_submit_sense_urb(shost, GFP_ATOMIC, tag)) {
                 shost_printk(KERN_INFO, shost,
                              "%s: %s: submit sense urb failed\n",
                              __func__, fname);
                 return FAILED;
         }
-        if (uas_submit_task_urb(cmnd, GFP_NOIO, function, tag)) {
+        if (uas_submit_task_urb(cmnd, GFP_ATOMIC, function, tag)) {
                 shost_printk(KERN_INFO, shost,
                              "%s: %s: submit task mgmt urb failed\n",
                              __func__, fname);
                 return FAILED;
         }
-        if (0 == usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 3000)) {
+        spin_unlock_irqrestore(&devinfo->lock, flags);
+
+        if (usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 3000) == 0) {
                 shost_printk(KERN_INFO, shost,
                              "%s: %s timed out\n", __func__, fname);
                 return FAILED;
@@ -650,10 +682,14 @@ static int uas_eh_task_mgmt(struct scsi_cmnd *cmnd,
 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;
+        unsigned long flags;
         int ret;
 
         uas_log_cmd_state(cmnd, __func__);
+        spin_lock_irqsave(&devinfo->lock, flags);
         cmdinfo->state |= COMMAND_ABORTED;
+        spin_unlock_irqrestore(&devinfo->lock, flags);
         ret = uas_eh_task_mgmt(cmnd, "ABORT TASK", TMF_ABORT_TASK);
         return ret;
 }
@@ -875,6 +911,7 @@ static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
         init_usb_anchor(&devinfo->cmd_urbs);
         init_usb_anchor(&devinfo->sense_urbs);
         init_usb_anchor(&devinfo->data_urbs);
+        spin_lock_init(&devinfo->lock);
         uas_configure_endpoints(devinfo);
 
         result = scsi_init_shared_tag_map(shost, devinfo->qdepth - 3);