[PATCH 11/19] sg: add sg_iosubmit_v3 and sg_ioreceive_v3 ioctls

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Add ioctl(SG_IOSUBMIT_V3) and ioctl(SG_IORECEIVE_V3). These ioctls
are meant to be (almost) drop-in replacements for the write()/read()
async version 3 interface. They only accept the version 3 interface.

See the webpage at: http://sg.danny.cz/sg/sg_v40.html
specifically the table in the section titled: "12 SG interface
support changes".

If sgv3 is a struct sg_io_hdr object, suitably configured, then
    res = write(sg_fd, &sgv3, sizeof(sgv3));
and
    res = ioctl(sg_fd, SG_IOSUBMIT_V3, &sgv3);
are equivalent. Dito for read() and ioctl(SG_IORECEIVE_V3).

Note this inconsistency: for async/non-blocking usage, only
the v4 interface objects can use ioctl(SG_IOSUBMIT) and
(SG_IORECEIVE) while only v3 interface objects can use
ioctl(SG_IOSUBMIT_V3) and (SG_IORECEIVE_V3). However with
the sync usage both v3 and v4 interface objects can use
ioctl(SG_IO). The former action is preferred but existing
practice for sync usage (i.e. the current sg driver
supporting the v3 interface object with ioctl(SG_IO) while
the bsg driver continues to support the v4 interface object
with ioctl(SG_IO)) dictates the dual nature of ioctl(SG_IO).

Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
 drivers/scsi/sg.c      | 81 ++++++++++++++++++++++++++++++++++++++++--
 include/uapi/scsi/sg.h |  6 ++++
 2 files changed, 84 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7575dd66dbef..a261ad2c4567 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -12,9 +12,9 @@
  *
  */
 
-static int sg_version_num = 30536;	/* 2 digits for each component */
-#define SG_VERSION_STR "3.5.36"
-static char *sg_version_date = "20140603";
+static int sg_version_num = 40001;	/* 2 digits for each component */
+#define SG_VERSION_STR "4.0.01"
+static char *sg_version_date = "20190520";
 
 #include <linux/module.h>
 
@@ -815,6 +815,24 @@ sg_ctl_iosubmit(struct file *filp, struct sg_fd *sfp, void __user *p)
 	return -EPERM;
 }
 
+static int
+sg_ctl_iosubmit_v3(struct file *filp, struct sg_fd *sfp, void __user *p)
+{
+	int res;
+	u8 hdr_store[SZ_SG_IO_V4];      /* max(v3interface, v4interface) */
+	struct sg_io_hdr *h3p = (struct sg_io_hdr *)hdr_store;
+	struct sg_device *sdp = sfp->parentdp;
+
+	res = sg_allow_if_err_recovery(sdp, (filp->f_flags & O_NONBLOCK));
+	if (unlikely(res))
+		return res;
+	if (copy_from_user(h3p, p, SZ_SG_IO_HDR))
+		return -EFAULT;
+	if (h3p->interface_id == 'S')
+		return sg_v3_submit(filp, sfp, h3p, false, NULL);
+	return -EPERM;
+}
+
 static void
 sg_execute_cmd(struct sg_fd *sfp, struct sg_request *srp)
 {
@@ -1188,6 +1206,57 @@ sg_ctl_ioreceive(struct file *filp, struct sg_fd *sfp, void __user *p)
 	return sg_v4_receive(sfp, srp, p, h4p);
 }
 
+/*
+ * Called when ioctl(SG_IORECEIVE_V3) received. Expects a v3 interface.
+ * Checks if O_NONBLOCK file flag given, if not checks given flags field
+ * to see if SGV4_FLAG_IMMED is set. Either of these implies non blocking.
+ * When non-blocking and there is no request waiting, yields EAGAIN;
+ * otherwise it waits.
+ */
+static int
+sg_ctl_ioreceive_v3(struct file *filp, struct sg_fd *sfp, void __user *p)
+{
+	bool non_block = !!(filp->f_flags & O_NONBLOCK);
+	int res;
+	int pack_id = SG_PACK_ID_WILDCARD;
+	u8 v3_holder[SZ_SG_IO_HDR];
+	struct sg_io_hdr *h3p = (struct sg_io_hdr *)v3_holder;
+	struct sg_device *sdp = sfp->parentdp;
+	struct sg_request *srp;
+
+	res = sg_allow_if_err_recovery(sdp, non_block);
+	if (unlikely(res))
+		return res;
+	/* Get first three 32 bit integers: guard, proto+subproto */
+	if (copy_from_user(h3p, p, SZ_SG_IO_HDR))
+		return -EFAULT;
+	/* for v3: interface_id=='S' (in a 32 bit int) */
+	if (h3p->interface_id != 'S')
+		return -EPERM;
+	if (h3p->flags & SGV4_FLAG_IMMED)
+		non_block = true;	/* set by either this or O_NONBLOCK */
+	SG_LOG(3, sdp, "%s: non_block(+IMMED)=%d\n", __func__, non_block);
+
+	if (test_bit(SG_FFD_FORCE_PACKID, sfp->ffd_bm))
+		pack_id = h3p->pack_id;
+
+	srp = sg_find_srp_by_id(sfp, pack_id);
+	if (!srp) {     /* nothing available so wait on packet or */
+		if (unlikely(atomic_read(&sdp->detaching)))
+			return -ENODEV;
+		if (non_block)
+			return -EAGAIN;
+		res = wait_event_interruptible
+				(sfp->read_wait,
+				 sg_get_ready_srp(sfp, &srp, pack_id));
+		if (unlikely(atomic_read(&sdp->detaching)))
+			return -ENODEV;
+		if (unlikely(res))
+			return res;	/* signal --> -ERESTARTSYS */
+	}	/* now srp should be valid */
+	return sg_v3_receive(sfp, srp, p);
+}
+
 static int
 sg_rd_v1v2(void __user *buf, int count, struct sg_fd *sfp,
 	   struct sg_request *srp)
@@ -1842,9 +1911,15 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 	case SG_IOSUBMIT:
 		SG_LOG(3, sdp, "%s:    SG_IOSUBMIT\n", __func__);
 		return sg_ctl_iosubmit(filp, sfp, p);
+	case SG_IOSUBMIT_V3:
+		SG_LOG(3, sdp, "%s:    SG_IOSUBMIT_V3\n", __func__);
+		return sg_ctl_iosubmit_v3(filp, sfp, p);
 	case SG_IORECEIVE:
 		SG_LOG(3, sdp, "%s:    SG_IORECEIVE\n", __func__);
 		return sg_ctl_ioreceive(filp, sfp, p);
+	case SG_IORECEIVE_V3:
+		SG_LOG(3, sdp, "%s:    SG_IORECEIVE_V3\n", __func__);
+		return sg_ctl_ioreceive_v3(filp, sfp, p);
 	case SG_IOABORT:
 		SG_LOG(3, sdp, "%s:    SG_IOABORT\n", __func__);
 		if (read_only)
diff --git a/include/uapi/scsi/sg.h b/include/uapi/scsi/sg.h
index cd58f918a784..8181e36442a8 100644
--- a/include/uapi/scsi/sg.h
+++ b/include/uapi/scsi/sg.h
@@ -359,6 +359,12 @@ struct sg_header {
 /* Provides identifying info about a prior submission (e.g. a tag) */
 #define SG_IOABORT _IOW(SG_IOCTL_MAGIC_NUM, 0x43, struct sg_io_v4)
 
+/* Submits a v3 interface object to driver */
+#define SG_IOSUBMIT_V3 _IOWR(SG_IOCTL_MAGIC_NUM, 0x45, struct sg_io_hdr)
+
+/* Gives some v3 identifying info to driver, receives associated response */
+#define SG_IORECEIVE_V3 _IOWR(SG_IOCTL_MAGIC_NUM, 0x46, struct sg_io_hdr)
+
 /* command queuing is always on when the v3 or v4 interface is used */
 #define SG_DEF_COMMAND_Q 0
 
-- 
2.17.1




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]

  Powered by Linux