diff mbox series

[v5,13/23] sg: ioctl handling

Message ID 20191008075022.30055-14-dgilbert@interlog.com (mailing list archive)
State Deferred
Headers show
Series sg: add v4 interface | expand

Commit Message

Douglas Gilbert Oct. 8, 2019, 7:50 a.m. UTC 
Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
is the main entry point for ioctls used on this driver's
devices.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
 drivers/scsi/sg.c | 325 ++++++++++++++++++++++++++++------------------
 1 file changed, 200 insertions(+), 125 deletions(-)

Comments

Hannes Reinecke Oct. 18, 2019, 10:12 a.m. UTC | #1 
On 10/8/19 9:50 AM, Douglas Gilbert wrote:
> Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
> is the main entry point for ioctls used on this driver's
> devices.
> 
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
> ---
>  drivers/scsi/sg.c | 325 ++++++++++++++++++++++++++++------------------
>  1 file changed, 200 insertions(+), 125 deletions(-)
> 
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 2796fef42837..90753f7759c7 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -72,6 +72,9 @@ static char *sg_version_date = "20190606";
>   */
>  #define SG_MAX_CDB_SIZE 252
>  
> +#define uptr64(val) ((void __user *)(uintptr_t)(val))
> +#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
> +
>  #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>  
>  /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */

These defines are used only once; I'd rather drop them and do the
conversion in-place.

Cheers,

Hannes
Douglas Gilbert Oct. 24, 2019, 2:47 a.m. UTC | #2 
On 2019-10-18 6:12 a.m., Hannes Reinecke wrote:
> On 10/8/19 9:50 AM, Douglas Gilbert wrote:
>> Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
>> is the main entry point for ioctls used on this driver's
>> devices.
>>
>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>> ---
>>   drivers/scsi/sg.c | 325 ++++++++++++++++++++++++++++------------------
>>   1 file changed, 200 insertions(+), 125 deletions(-)
>>
>> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
>> index 2796fef42837..90753f7759c7 100644
>> --- a/drivers/scsi/sg.c
>> +++ b/drivers/scsi/sg.c
>> @@ -72,6 +72,9 @@ static char *sg_version_date = "20190606";
>>    */
>>   #define SG_MAX_CDB_SIZE 252
>>   
>> +#define uptr64(val) ((void __user *)(uintptr_t)(val))
>> +#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
>> +
>>   #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
>>   
>>   /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
> 
> These defines are used only once; I'd rather drop them and do the
> conversion in-place.

Okay, I'll take them out. And they will go back in in patch 28
as their main use is to handle the way the sg v4 interface
send pointers through 64 bit integers. The first one should be
familiar to anyone who has worked on block/bsg.h .

Doug Gilbert
diff mbox series

Patch

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 2796fef42837..90753f7759c7 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -72,6 +72,9 @@  static char *sg_version_date = "20190606";
  */
 #define SG_MAX_CDB_SIZE 252
 
+#define uptr64(val) ((void __user *)(uintptr_t)(val))
+#define cuptr64(val) ((const void __user *)(uintptr_t)(val))
+
 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
 
 /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */
@@ -1013,16 +1016,111 @@  sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
 	}
 }
 
+/*
+ * Handles ioctl(SG_IO) for blocking (sync) usage of v3 or v4 interface.
+ * Returns 0 on success else a negated errno.
+ */
+static int
+sg_ctl_sg_io(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
+	     void __user *p)
+{
+	bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
+	int res;
+	struct sg_request *srp;
+
+	res = sg_allow_if_err_recovery(sdp, false);
+	if (res)
+		return res;
+	res = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
+			true, &srp);
+	if (res < 0)
+		return res;
+	res = wait_event_interruptible
+		(sfp->read_wait, (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
+	if (SG_IS_DETACHING(sdp))
+		return -ENODEV;
+	spin_lock_irq(&sfp->rq_list_lock);
+	if (srp->done) {
+		srp->done = 2;
+		spin_unlock_irq(&sfp->rq_list_lock);
+		res = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
+		return (res < 0) ? res : 0;
+	}
+	srp->orphan = 1;
+	spin_unlock_irq(&sfp->rq_list_lock);
+	return res;	/* -ERESTARTSYS because signal hit process */
+}
+
+static int
+sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz)
+{
+	if (want_rsv_sz != sfp->reserve.buflen) {
+		if (sfp->mmap_called ||
+		    sfp->res_in_use) {
+			return -EBUSY;
+		}
+
+		sg_remove_scat(sfp, &sfp->reserve);
+		sg_build_reserve(sfp, want_rsv_sz);
+	}
+	return 0;
+}
+
+static int
+sg_ctl_req_tbl(struct sg_fd *sfp, void __user *p)
+{
+	int result;
+	unsigned long iflags;
+	sg_req_info_t *rinfo;
+
+	rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
+			GFP_KERNEL);
+	if (!rinfo)
+		return -ENOMEM;
+	spin_lock_irqsave(&sfp->rq_list_lock, iflags);
+	sg_fill_request_table(sfp, rinfo);
+	spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+	result = copy_to_user(p, rinfo,
+			      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
+	result = result ? -EFAULT : 0;
+	kfree(rinfo);
+	return result;
+}
+
+static int
+sg_ctl_scsi_id(struct scsi_device *sdev, struct sg_fd *sfp, void __user *p)
+{
+	struct sg_scsi_id ss_id;
+
+	SG_LOG(3, sfp, "%s:    SG_GET_SCSI_ID\n", __func__);
+	ss_id.host_no = sdev->host->host_no;
+	ss_id.channel = sdev->channel;
+	ss_id.scsi_id = sdev->id;
+	ss_id.lun = sdev->lun;
+	ss_id.scsi_type = sdev->type;
+	ss_id.h_cmd_per_lun = sdev->host->cmd_per_lun;
+	ss_id.d_queue_depth = sdev->queue_depth;
+	ss_id.unused[0] = 0;
+	ss_id.unused[1] = 0;
+	if (copy_to_user(p, &ss_id, sizeof(struct sg_scsi_id)))
+		return -EFAULT;
+	return 0;
+}
+
 static long
 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 {
-	void __user *p = (void __user *)arg;
+	bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
+	int val;
+	int result = 0;
+	void __user *p = uptr64(arg);
 	int __user *ip = p;
-	int result, val, read_only;
 	struct sg_device *sdp;
 	struct sg_fd *sfp;
 	struct sg_request *srp;
+	struct scsi_device *sdev;
 	unsigned long iflags;
+	__maybe_unused const char *pmlp = ", pass to mid-level";
 
 	sfp = filp->private_data;
 	sdp = sfp->parentdp;
@@ -1030,139 +1128,118 @@  sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 	       !!(filp->f_flags & O_NONBLOCK));
 	if (!sdp)
 		return -ENXIO;
-	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
+	if (unlikely(SG_IS_DETACHING(sdp)))
+		return -ENODEV;
+	sdev = sdp->device;
 
 	switch (cmd_in) {
 	case SG_IO:
-		result = sg_allow_if_err_recovery(sdp, false);
-		if (result)
-			return result;
-		result = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
-				   true, &srp);
-		if (result < 0)
-			return result;
-		result = wait_event_interruptible(sfp->read_wait,
-			(srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
-		if (SG_IS_DETACHING(sdp))
-			return -ENODEV;
-		spin_lock_irq(&sfp->rq_list_lock);
-		if (srp->done) {
-			srp->done = 2;
-			spin_unlock_irq(&sfp->rq_list_lock);
-			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
-			return (result < 0) ? result : 0;
-		}
-		srp->orphan = 1;
-		spin_unlock_irq(&sfp->rq_list_lock);
-		return result;	/* -ERESTARTSYS because signal hit process */
-	case SG_SET_TIMEOUT:
-		result = get_user(val, ip);
-		if (result)
-			return result;
-		if (val < 0)
-			return -EIO;
-		if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
-			val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
-				    INT_MAX);
-		sfp->timeout_user = val;
-		sfp->timeout = mult_frac(val, HZ, USER_HZ);
-
-		return 0;
-	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
-				/* strange ..., for backward compatibility */
-		return sfp->timeout_user;
-	case SG_SET_FORCE_LOW_DMA:
-		/*
-		 * N.B. This ioctl never worked properly, but failed to
-		 * return an error value. So returning '0' to keep compability
-		 * with legacy applications.
-		 */
-		return 0;
-	case SG_GET_LOW_DMA:
-		return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
+		return sg_ctl_sg_io(filp, sdp, sfp, p);
 	case SG_GET_SCSI_ID:
-		if (!SG_IS_DETACHING(sdp)) {
-			struct sg_scsi_id ss_id;
-
-			ss_id.host_no = sdp->device->host->host_no;
-			ss_id.channel = sdp->device->channel;
-			ss_id.scsi_id = sdp->device->id;
-			ss_id.lun = sdp->device->lun;
-			ss_id.scsi_type = sdp->device->type;
-			ss_id.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
-			ss_id.d_queue_depth = sdp->device->queue_depth;
-			ss_id.unused[0] = 0;
-			ss_id.unused[1] = 0;
-			if (copy_to_user(p, &ss_id, sizeof(struct sg_scsi_id)))
-				return -EFAULT;
-			return 0;
-		}
-		return -ENODEV;
+		return sg_ctl_scsi_id(sdev, sfp, p);
 	case SG_SET_FORCE_PACK_ID:
+		SG_LOG(3, sfp, "%s:    SG_SET_FORCE_PACK_ID\n", __func__);
 		result = get_user(val, ip);
 		if (result)
 			return result;
 		sfp->force_packid = val ? 1 : 0;
 		return 0;
 	case SG_GET_PACK_ID:
+		val = -1;
 		spin_lock_irqsave(&sfp->rq_list_lock, iflags);
 		list_for_each_entry(srp, &sfp->rq_list, entry) {
 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
-				spin_unlock_irqrestore(&sfp->rq_list_lock,
-						       iflags);
-				put_user(srp->header.pack_id, ip);
-				return 0;
+				val = srp->header.pack_id;
+				break;
 			}
 		}
 		spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
-		put_user(-1, ip);
+		SG_LOG(3, sfp, "%s:    SG_GET_PACK_ID=%d\n", __func__, val);
+		put_user(val, ip);
 		return 0;
 	case SG_GET_NUM_WAITING:
 		return put_user(atomic_read(&sfp->waiting), ip);
 	case SG_GET_SG_TABLESIZE:
+		SG_LOG(3, sfp, "%s:    SG_GET_SG_TABLESIZE=%d\n", __func__,
+		       sdp->max_sgat_sz);
 		return put_user(sdp->max_sgat_sz, ip);
 	case SG_SET_RESERVED_SIZE:
-		result = get_user(val, ip);
-		if (result)
-			return result;
-                if (val < 0)
-                        return -EINVAL;
-		val = min_t(int, val,
-			    max_sectors_bytes(sdp->device->request_queue));
 		mutex_lock(&sfp->f_mutex);
-		if (val != sfp->reserve.buflen) {
-			if (sfp->mmap_called ||
-			    sfp->res_in_use) {
-				mutex_unlock(&sfp->f_mutex);
-				return -EBUSY;
+		result = get_user(val, ip);
+		if (!result) {
+			if (val >= 0 && val <= (1024 * 1024 * 1024)) {
+				result = sg_set_reserved_sz(sfp, val);
+			} else {
+				SG_LOG(3, sfp, "%s: invalid size\n", __func__);
+				result = -EINVAL;
 			}
-
-			sg_remove_scat(sfp, &sfp->reserve);
-			sg_build_reserve(sfp, val);
 		}
 		mutex_unlock(&sfp->f_mutex);
-		return 0;
+		return result;
 	case SG_GET_RESERVED_SIZE:
 		val = min_t(int, sfp->reserve.buflen,
-			    max_sectors_bytes(sdp->device->request_queue));
+			    max_sectors_bytes(sdev->request_queue));
+		SG_LOG(3, sfp, "%s:    SG_GET_RESERVED_SIZE=%d\n",
+		       __func__, val);
 		return put_user(val, ip);
 	case SG_SET_COMMAND_Q:
+		SG_LOG(3, sfp, "%s:    SG_SET_COMMAND_Q\n", __func__);
 		result = get_user(val, ip);
 		if (result)
 			return result;
 		sfp->cmd_q = val ? 1 : 0;
 		return 0;
 	case SG_GET_COMMAND_Q:
+		SG_LOG(3, sfp, "%s:    SG_GET_COMMAND_Q\n", __func__);
 		return put_user((int) sfp->cmd_q, ip);
 	case SG_SET_KEEP_ORPHAN:
+		SG_LOG(3, sfp, "%s:    SG_SET_KEEP_ORPHAN\n", __func__);
 		result = get_user(val, ip);
 		if (result)
 			return result;
 		sfp->keep_orphan = val;
 		return 0;
 	case SG_GET_KEEP_ORPHAN:
+		SG_LOG(3, sfp, "%s:    SG_GET_KEEP_ORPHAN\n", __func__);
 		return put_user((int) sfp->keep_orphan, ip);
+	case SG_GET_VERSION_NUM:
+		SG_LOG(3, sfp, "%s:    SG_GET_VERSION_NUM\n", __func__);
+		return put_user(sg_version_num, ip);
+	case SG_GET_REQUEST_TABLE:
+		return sg_ctl_req_tbl(sfp, p);
+	case SG_SCSI_RESET:
+		SG_LOG(3, sfp, "%s:    SG_SCSI_RESET\n", __func__);
+		break;
+	case SG_SET_TIMEOUT:
+		SG_LOG(3, sfp, "%s:    SG_SET_TIMEOUT\n", __func__);
+		result = get_user(val, ip);
+		if (result)
+			return result;
+		if (val < 0)
+			return -EIO;
+		if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
+			val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
+				    INT_MAX);
+		sfp->timeout_user = val;
+		sfp->timeout = mult_frac(val, HZ, USER_HZ);
+		return 0;
+	case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
+				/* strange ..., for backward compatibility */
+		SG_LOG(3, sfp, "%s:    SG_GET_TIMEOUT\n", __func__);
+		return sfp->timeout_user;
+	case SG_SET_FORCE_LOW_DMA:
+		/*
+		 * N.B. This ioctl never worked properly, but failed to
+		 * return an error value. So returning '0' to keep
+		 * compatibility with legacy applications.
+		 */
+		SG_LOG(3, sfp, "%s:    SG_SET_FORCE_LOW_DMA\n", __func__);
+		return 0;
+	case SG_GET_LOW_DMA:
+		SG_LOG(3, sfp, "%s:    SG_GET_LOW_DMA\n", __func__);
+		return put_user((int)sdev->host->unchecked_isa_dma, ip);
 	case SG_NEXT_CMD_LEN:
+		SG_LOG(3, sfp, "%s:    SG_NEXT_CMD_LEN\n", __func__);
 		result = get_user(val, ip);
 		if (result)
 			return result;
@@ -1170,75 +1247,73 @@  sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 			return -ENOMEM;
 		sfp->next_cmd_len = (val > 0) ? val : 0;
 		return 0;
-	case SG_GET_VERSION_NUM:
-		return put_user(sg_version_num, ip);
 	case SG_GET_ACCESS_COUNT:
+		SG_LOG(3, sfp, "%s:    SG_GET_ACCESS_COUNT\n", __func__);
 		/* faked - we don't have a real access count anymore */
-		val = (sdp->device ? 1 : 0);
+		val = (sdev ? 1 : 0);
 		return put_user(val, ip);
-	case SG_GET_REQUEST_TABLE:
-		{
-			sg_req_info_t *rinfo;
-
-			rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
-					GFP_KERNEL);
-			if (!rinfo)
-				return -ENOMEM;
-			spin_lock_irqsave(&sfp->rq_list_lock, iflags);
-			sg_fill_request_table(sfp, rinfo);
-			spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
-			result = copy_to_user(p, rinfo,
-					      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
-			result = result ? -EFAULT : 0;
-			kfree(rinfo);
-			return result;
-		}
 	case SG_EMULATED_HOST:
-		if (SG_IS_DETACHING(sdp))
-			return -ENODEV;
-		return put_user(sdp->device->host->hostt->emulated, ip);
+		SG_LOG(3, sfp, "%s:    SG_EMULATED_HOST\n", __func__);
+		return put_user(sdev->host->hostt->emulated, ip);
 	case SCSI_IOCTL_SEND_COMMAND:
-		if (SG_IS_DETACHING(sdp))
-			return -ENODEV;
-		return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
+		SG_LOG(3, sfp, "%s:    SCSI_IOCTL_SEND_COMMAND\n", __func__);
+		return sg_scsi_ioctl(sdev->request_queue, NULL, filp->f_mode,
+				     p);
 	case SG_SET_DEBUG:
+		SG_LOG(3, sfp, "%s:    SG_SET_DEBUG\n", __func__);
 		result = get_user(val, ip);
 		if (result)
 			return result;
 		assign_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm, val);
 		return 0;
 	case BLKSECTGET:
-		return put_user(max_sectors_bytes(sdp->device->request_queue),
-				ip);
+		SG_LOG(3, sfp, "%s:    BLKSECTGET\n", __func__);
+		return put_user(max_sectors_bytes(sdev->request_queue), ip);
 	case BLKTRACESETUP:
-		return blk_trace_setup(sdp->device->request_queue,
+		SG_LOG(3, sfp, "%s:    BLKTRACESETUP\n", __func__);
+		return blk_trace_setup(sdev->request_queue,
 				       sdp->disk->disk_name,
 				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
 				       NULL, p);
 	case BLKTRACESTART:
-		return blk_trace_startstop(sdp->device->request_queue, 1);
+		SG_LOG(3, sfp, "%s:    BLKTRACESTART\n", __func__);
+		return blk_trace_startstop(sdev->request_queue, 1);
 	case BLKTRACESTOP:
-		return blk_trace_startstop(sdp->device->request_queue, 0);
+		SG_LOG(3, sfp, "%s:    BLKTRACESTOP\n", __func__);
+		return blk_trace_startstop(sdev->request_queue, 0);
 	case BLKTRACETEARDOWN:
-		return blk_trace_remove(sdp->device->request_queue);
+		SG_LOG(3, sfp, "%s:    BLKTRACETEARDOWN\n", __func__);
+		return blk_trace_remove(sdev->request_queue);
 	case SCSI_IOCTL_GET_IDLUN:
+		SG_LOG(3, sfp, "%s:    SCSI_IOCTL_GET_IDLUN %s\n", __func__,
+		       pmlp);
+		break;
 	case SCSI_IOCTL_GET_BUS_NUMBER:
+		SG_LOG(3, sfp, "%s:    SCSI_IOCTL_GET_BUS_NUMBER%s\n",
+		       __func__, pmlp);
+		break;
 	case SCSI_IOCTL_PROBE_HOST:
+		SG_LOG(3, sfp, "%s:    SCSI_IOCTL_PROBE_HOST%s",
+		       __func__, pmlp);
+		break;
 	case SG_GET_TRANSFORM:
-	case SG_SCSI_RESET:
-		if (SG_IS_DETACHING(sdp))
-			return -ENODEV;
+		SG_LOG(3, sfp, "%s:    SG_GET_TRANSFORM%s\n", __func__, pmlp);
+		break;
+	case SG_SET_TRANSFORM:
+		SG_LOG(3, sfp, "%s:    SG_SET_TRANSFORM%s\n", __func__, pmlp);
 		break;
 	default:
+		SG_LOG(3, sfp, "%s:    unrecognized ioctl [0x%x]%s\n",
+		       __func__, cmd_in, pmlp);
 		if (read_only)
-			return -EPERM;	/* don't know so take safe approach */
+			return -EPERM;	/* don't know, so take safer approach */
 		break;
 	}
 
 	result = sg_allow_if_err_recovery(sdp, filp->f_flags & O_NDELAY);
 	if (result)
 		return result;
-	return scsi_ioctl(sdp->device, cmd_in, p);
+	return scsi_ioctl(sdev, cmd_in, p);
 }
 
 #if IS_ENABLED(CONFIG_COMPAT)