[v11,01/44] sg: move functions around

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 20472aaaf630..1e020298e939 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -8,11 +8,12 @@ 
  * Original driver (sg.c):
  *        Copyright (C) 1992 Lawrence Foard
  * Version 2 and 3 extensions to driver:
- *        Copyright (C) 1998 - 2014 Douglas Gilbert
+ *        Copyright (C) 1998 - 2019 Douglas Gilbert
  */
 
-static int sg_version_num = 30536;	/* 2 digits for each component */
-#define SG_VERSION_STR "3.5.36"
+static int sg_version_num = 30901;  /* [x]xyyzz where [x] empty when x=0 */
+#define SG_VERSION_STR "3.9.01"		/* [x]x.[y]y.zz */
+static char *sg_version_date = "20190606";
 
 /*
  *  D. P. Gilbert (dgilbert@interlog.com), notes:
@@ -47,6 +48,7 @@  static int sg_version_num = 30536;	/* 2 digits for each component */
 #include <linux/ratelimit.h>
 #include <linux/uio.h>
 #include <linux/cred.h> /* for sg_check_file_access() */
+#include <linux/proc_fs.h>
 
 #include "scsi.h"
 #include <scsi/scsi_dbg.h>
@@ -57,12 +59,6 @@  static int sg_version_num = 30536;	/* 2 digits for each component */
 
 #include "scsi_logging.h"
 
-#ifdef CONFIG_SCSI_PROC_FS
-#include <linux/proc_fs.h>
-static char *sg_version_date = "20140603";
-
-static int sg_proc_init(void);
-#endif
 
 #define SG_ALLOW_DIO_DEF 0
 
@@ -173,11 +169,11 @@  typedef struct sg_device { /* holds the state of each scsi generic device */
 
 /* tasklet or soft irq callback */
 static void sg_rq_end_io(struct request *rq, blk_status_t status);
+/* Declarations of other static functions used before they are defined */
+static int sg_proc_init(void);
 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 static int sg_finish_rem_req(Sg_request * srp);
 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
-static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
-			   Sg_request * srp);
 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 			const char __user *buf, size_t count, int blocking,
 			int read_only, int sg_io_owned, Sg_request **o_srp);
@@ -190,7 +186,6 @@  static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 static void sg_remove_sfp(struct kref *);
-static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 static Sg_request *sg_add_request(Sg_fd * sfp);
 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 static Sg_device *sg_get_dev(int dev);
@@ -232,16 +227,6 @@  static int sg_check_file_access(struct file *filp, const char *caller)
 	return 0;
 }
 
-static int sg_allow_access(struct file *filp, unsigned char *cmd)
-{
-	struct sg_fd *sfp = filp->private_data;
-
-	if (sfp->parentdp->device->type == TYPE_SCANNER)
-		return 0;
-
-	return blk_verify_command(cmd, filp->f_mode);
-}
-
 static int
 open_wait(Sg_device *sdp, int flags)
 {
@@ -405,196 +390,6 @@  sg_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
-{
-	struct sg_header __user *old_hdr = buf;
-	int reply_len;
-
-	if (count >= SZ_SG_HEADER) {
-		/* negative reply_len means v3 format, otherwise v1/v2 */
-		if (get_user(reply_len, &old_hdr->reply_len))
-			return -EFAULT;
-
-		if (reply_len >= 0)
-			return get_user(*pack_id, &old_hdr->pack_id);
-
-		if (in_compat_syscall() &&
-		    count >= sizeof(struct compat_sg_io_hdr)) {
-			struct compat_sg_io_hdr __user *hp = buf;
-
-			return get_user(*pack_id, &hp->pack_id);
-		}
-
-		if (count >= sizeof(struct sg_io_hdr)) {
-			struct sg_io_hdr __user *hp = buf;
-
-			return get_user(*pack_id, &hp->pack_id);
-		}
-	}
-
-	/* no valid header was passed, so ignore the pack_id */
-	*pack_id = -1;
-	return 0;
-}
-
-static ssize_t
-sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
-{
-	Sg_device *sdp;
-	Sg_fd *sfp;
-	Sg_request *srp;
-	int req_pack_id = -1;
-	sg_io_hdr_t *hp;
-	struct sg_header *old_hdr;
-	int retval;
-
-	/*
-	 * This could cause a response to be stranded. Close the associated
-	 * file descriptor to free up any resources being held.
-	 */
-	retval = sg_check_file_access(filp, __func__);
-	if (retval)
-		return retval;
-
-	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
-		return -ENXIO;
-	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
-				      "sg_read: count=%d\n", (int) count));
-
-	if (sfp->force_packid)
-		retval = get_sg_io_pack_id(&req_pack_id, buf, count);
-	if (retval)
-		return retval;
-
-	srp = sg_get_rq_mark(sfp, req_pack_id);
-	if (!srp) {		/* now wait on packet to arrive */
-		if (atomic_read(&sdp->detaching))
-			return -ENODEV;
-		if (filp->f_flags & O_NONBLOCK)
-			return -EAGAIN;
-		retval = wait_event_interruptible(sfp->read_wait,
-			(atomic_read(&sdp->detaching) ||
-			(srp = sg_get_rq_mark(sfp, req_pack_id))));
-		if (atomic_read(&sdp->detaching))
-			return -ENODEV;
-		if (retval)
-			/* -ERESTARTSYS as signal hit process */
-			return retval;
-	}
-	if (srp->header.interface_id != '\0')
-		return sg_new_read(sfp, buf, count, srp);
-
-	hp = &srp->header;
-	old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
-	if (!old_hdr)
-		return -ENOMEM;
-
-	old_hdr->reply_len = (int) hp->timeout;
-	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
-	old_hdr->pack_id = hp->pack_id;
-	old_hdr->twelve_byte =
-	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
-	old_hdr->target_status = hp->masked_status;
-	old_hdr->host_status = hp->host_status;
-	old_hdr->driver_status = hp->driver_status;
-	if ((CHECK_CONDITION & hp->masked_status) ||
-	    (DRIVER_SENSE & hp->driver_status))
-		memcpy(old_hdr->sense_buffer, srp->sense_b,
-		       sizeof (old_hdr->sense_buffer));
-	switch (hp->host_status) {
-	/* This setup of 'result' is for backward compatibility and is best
-	   ignored by the user who should use target, host + driver status */
-	case DID_OK:
-	case DID_PASSTHROUGH:
-	case DID_SOFT_ERROR:
-		old_hdr->result = 0;
-		break;
-	case DID_NO_CONNECT:
-	case DID_BUS_BUSY:
-	case DID_TIME_OUT:
-		old_hdr->result = EBUSY;
-		break;
-	case DID_BAD_TARGET:
-	case DID_ABORT:
-	case DID_PARITY:
-	case DID_RESET:
-	case DID_BAD_INTR:
-		old_hdr->result = EIO;
-		break;
-	case DID_ERROR:
-		old_hdr->result = (srp->sense_b[0] == 0 && 
-				  hp->masked_status == GOOD) ? 0 : EIO;
-		break;
-	default:
-		old_hdr->result = EIO;
-		break;
-	}
-
-	/* Now copy the result back to the user buffer.  */
-	if (count >= SZ_SG_HEADER) {
-		if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
-			retval = -EFAULT;
-			goto free_old_hdr;
-		}
-		buf += SZ_SG_HEADER;
-		if (count > old_hdr->reply_len)
-			count = old_hdr->reply_len;
-		if (count > SZ_SG_HEADER) {
-			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
-				retval = -EFAULT;
-				goto free_old_hdr;
-			}
-		}
-	} else
-		count = (old_hdr->result == 0) ? 0 : -EIO;
-	sg_finish_rem_req(srp);
-	sg_remove_request(sfp, srp);
-	retval = count;
-free_old_hdr:
-	kfree(old_hdr);
-	return retval;
-}
-
-static ssize_t
-sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
-{
-	sg_io_hdr_t *hp = &srp->header;
-	int err = 0, err2;
-	int len;
-
-	if (in_compat_syscall()) {
-		if (count < sizeof(struct compat_sg_io_hdr)) {
-			err = -EINVAL;
-			goto err_out;
-		}
-	} else if (count < SZ_SG_IO_HDR) {
-		err = -EINVAL;
-		goto err_out;
-	}
-	hp->sb_len_wr = 0;
-	if ((hp->mx_sb_len > 0) && hp->sbp) {
-		if ((CHECK_CONDITION & hp->masked_status) ||
-		    (DRIVER_SENSE & hp->driver_status)) {
-			int sb_len = SCSI_SENSE_BUFFERSIZE;
-			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
-			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
-			len = (len > sb_len) ? sb_len : len;
-			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
-				err = -EFAULT;
-				goto err_out;
-			}
-			hp->sb_len_wr = len;
-		}
-	}
-	if (hp->masked_status || hp->host_status || hp->driver_status)
-		hp->info |= SG_INFO_CHECK;
-	err = put_sg_io_hdr(hp, buf);
-err_out:
-	err2 = sg_finish_rem_req(srp);
-	sg_remove_request(sfp, srp);
-	return err ? : err2 ? : count;
-}
-
 static ssize_t
 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 {
@@ -708,6 +503,16 @@  sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 	return (k < 0) ? k : count;
 }
 
+static int sg_allow_access(struct file *filp, unsigned char *cmd)
+{
+	struct sg_fd *sfp = filp->private_data;
+
+	if (sfp->parentdp->device->type == TYPE_SCANNER)
+		return 0;
+
+	return blk_verify_command(cmd, filp->f_mode);
+}
+
 static ssize_t
 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 		 size_t count, int blocking, int read_only, int sg_io_owned,
@@ -834,6 +639,75 @@  sg_common_write(Sg_fd * sfp, Sg_request * srp,
 	return 0;
 }
 
+/*
+ * read(2) related functions follow. They are shown after write(2) related
+ * functions. Apart from read(2) itself, ioctl(SG_IORECEIVE) and the second
+ * half of the ioctl(SG_IO) share code with read(2).
+ */
+
+static Sg_request *
+sg_get_rq_mark(Sg_fd *sfp, int pack_id)
+{
+	Sg_request *resp;
+	unsigned long iflags;
+
+	write_lock_irqsave(&sfp->rq_list_lock, iflags);
+	list_for_each_entry(resp, &sfp->rq_list, entry) {
+		/* look for requests that are ready + not SG_IO owned */
+		if (resp->done == 1 && !resp->sg_io_owned &&
+		    (-1 == pack_id || resp->header.pack_id == pack_id)) {
+			resp->done = 2;	/* guard against other readers */
+			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+			return resp;
+		}
+	}
+	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+	return NULL;
+}
+
+static ssize_t
+sg_new_read(Sg_fd *sfp, char __user *buf, size_t count, Sg_request *srp)
+{
+	sg_io_hdr_t *hp = &srp->header;
+	int err = 0, err2;
+	int len;
+
+	if (in_compat_syscall()) {
+		if (count < sizeof(struct compat_sg_io_hdr)) {
+			err = -EINVAL;
+			goto err_out;
+		}
+	} else if (count < SZ_SG_IO_HDR) {
+		err = -EINVAL;
+		goto err_out;
+	}
+	hp->sb_len_wr = 0;
+	if (hp->mx_sb_len > 0 && hp->sbp) {
+		if ((CHECK_CONDITION & hp->masked_status) ||
+		    (DRIVER_SENSE & hp->driver_status)) {
+			int sb_len = SCSI_SENSE_BUFFERSIZE;
+
+			sb_len = (hp->mx_sb_len > sb_len) ? sb_len :
+							    hp->mx_sb_len;
+			/* Additional sense length field */
+			len = 8 + (int)srp->sense_b[7];
+			len = (len > sb_len) ? sb_len : len;
+			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
+				err = -EFAULT;
+				goto err_out;
+			}
+			hp->sb_len_wr = len;
+		}
+	}
+	if (hp->masked_status || hp->host_status || hp->driver_status)
+		hp->info |= SG_INFO_CHECK;
+	err = put_sg_io_hdr(hp, buf);
+err_out:
+	err2 = sg_finish_rem_req(srp);
+	sg_remove_request(sfp, srp);
+	return err ? : err2 ? : count;
+}
+
 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 {
 	unsigned long flags;
@@ -845,6 +719,171 @@  static int srp_done(Sg_fd *sfp, Sg_request *srp)
 	return ret;
 }
 
+static ssize_t
+sg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
+{
+	Sg_device *sdp;
+	Sg_fd *sfp;
+	Sg_request *srp;
+	int req_pack_id = -1;
+	sg_io_hdr_t *hp;
+	struct sg_header *old_hdr = NULL;
+	int retval = 0;
+
+	/*
+	 * This could cause a response to be stranded. Close the associated
+	 * file descriptor to free up any resources being held.
+	 */
+	retval = sg_check_file_access(filp, __func__);
+	if (retval)
+		return retval;
+
+	sfp = filp->private_data;
+	sdp = sfp->parentdp;
+	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
+				      "%s: count=%d\n", __func__,
+				      (int)count));
+	if (!sdp)
+		return -ENXIO;
+
+	if (!access_ok(buf, count))
+		return -EFAULT;
+	if (sfp->force_packid && count >= SZ_SG_HEADER) {
+		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
+		if (!old_hdr)
+			return -ENOMEM;
+		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
+			retval = -EFAULT;
+			goto free_old_hdr;
+		}
+		if (old_hdr->reply_len < 0) {
+			if (count >= SZ_SG_IO_HDR) {
+				sg_io_hdr_t *new_hdr;
+
+				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
+				if (!new_hdr) {
+					retval = -ENOMEM;
+					goto free_old_hdr;
+				}
+				retval = __copy_from_user
+				    (new_hdr, buf, SZ_SG_IO_HDR);
+				req_pack_id = new_hdr->pack_id;
+				kfree(new_hdr);
+				if (retval) {
+					retval = -EFAULT;
+					goto free_old_hdr;
+				}
+			}
+		} else {
+			req_pack_id = old_hdr->pack_id;
+		}
+	}
+	srp = sg_get_rq_mark(sfp, req_pack_id);
+	if (!srp) {		/* now wait on packet to arrive */
+		if (atomic_read(&sdp->detaching)) {
+			retval = -ENODEV;
+			goto free_old_hdr;
+		}
+		if (filp->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto free_old_hdr;
+		}
+		retval = wait_event_interruptible
+				(sfp->read_wait,
+				 (atomic_read(&sdp->detaching) ||
+				  (srp = sg_get_rq_mark(sfp, req_pack_id))));
+		if (atomic_read(&sdp->detaching)) {
+			retval = -ENODEV;
+			goto free_old_hdr;
+		}
+		if (retval) {
+			/* -ERESTARTSYS as signal hit process */
+			goto free_old_hdr;
+		}
+	}
+	if (srp->header.interface_id != '\0') {
+		retval = sg_new_read(sfp, buf, count, srp);
+		goto free_old_hdr;
+	}
+
+	hp = &srp->header;
+	if (!old_hdr) {
+		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
+		if (!old_hdr) {
+			retval = -ENOMEM;
+			goto free_old_hdr;
+		}
+	}
+	memset(old_hdr, 0, SZ_SG_HEADER);
+	old_hdr->reply_len = (int)hp->timeout;
+	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
+	old_hdr->pack_id = hp->pack_id;
+	old_hdr->twelve_byte =
+	    ((srp->data.cmd_opcode >= 0xc0) && (hp->cmd_len == 12)) ? 1 : 0;
+	old_hdr->target_status = hp->masked_status;
+	old_hdr->host_status = hp->host_status;
+	old_hdr->driver_status = hp->driver_status;
+	if ((hp->masked_status & CHECK_CONDITION) ||
+	    (hp->driver_status & DRIVER_SENSE))
+		memcpy(old_hdr->sense_buffer, srp->sense_b,
+		       sizeof(old_hdr->sense_buffer));
+	switch (hp->host_status) {
+	/*
+	 * This setup of 'result' is for backward compatibility and is best
+	 * ignored by the user who should use target, host + driver status
+	 */
+	case DID_OK:
+	case DID_PASSTHROUGH:
+	case DID_SOFT_ERROR:
+		old_hdr->result = 0;
+		break;
+	case DID_NO_CONNECT:
+	case DID_BUS_BUSY:
+	case DID_TIME_OUT:
+		old_hdr->result = EBUSY;
+		break;
+	case DID_BAD_TARGET:
+	case DID_ABORT:
+	case DID_PARITY:
+	case DID_RESET:
+	case DID_BAD_INTR:
+		old_hdr->result = EIO;
+		break;
+	case DID_ERROR:
+		old_hdr->result = (srp->sense_b[0] == 0 &&
+				  hp->masked_status == GOOD) ? 0 : EIO;
+		break;
+	default:
+		old_hdr->result = EIO;
+		break;
+	}
+
+	/* Now copy the result back to the user buffer.  */
+	if (count >= SZ_SG_HEADER) {
+		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
+			retval = -EFAULT;
+			goto free_old_hdr;
+		}
+		buf += SZ_SG_HEADER;
+		if (count > old_hdr->reply_len)
+			count = old_hdr->reply_len;
+		if (count > SZ_SG_HEADER) {
+			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
+				retval = -EFAULT;
+				goto free_old_hdr;
+			}
+		}
+	} else {
+		count = (old_hdr->result == 0) ? 0 : -EIO;
+	}
+	sg_finish_rem_req(srp);
+	sg_remove_request(sfp, srp);
+	retval = count;
+free_old_hdr:
+	kfree(old_hdr);
+	return retval;
+}
+
 static int max_sectors_bytes(struct request_queue *q)
 {
 	unsigned int max_sectors = queue_max_sectors(q);
@@ -1692,9 +1731,7 @@  init_sg(void)
 	sg_sysfs_valid = 1;
 	rc = scsi_register_interface(&sg_interface);
 	if (0 == rc) {
-#ifdef CONFIG_SCSI_PROC_FS
 		sg_proc_init();
-#endif				/* CONFIG_SCSI_PROC_FS */
 		return 0;
 	}
 	class_destroy(sg_sysfs_class);
@@ -1703,6 +1740,14 @@  init_sg(void)
 	return rc;
 }
 
+#ifndef CONFIG_SCSI_PROC_FS
+static int
+sg_proc_init(void)
+{
+	return 0;
+}
+#endif
+
 static void __exit
 exit_sg(void)
 {
@@ -2076,9 +2121,10 @@  sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
 			rem -= num;
 	}
 
-	if (k >= rsv_schp->k_use_sg)
+	if (k >= rsv_schp->k_use_sg) {
 		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 				 "sg_link_reserve: BAD size\n"));
+	}
 }
 
 static void
@@ -2099,26 +2145,6 @@  sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
 	sfp->res_in_use = 0;
 }
 
-static Sg_request *
-sg_get_rq_mark(Sg_fd * sfp, int pack_id)
-{
-	Sg_request *resp;
-	unsigned long iflags;
-
-	write_lock_irqsave(&sfp->rq_list_lock, iflags);
-	list_for_each_entry(resp, &sfp->rq_list, entry) {
-		/* look for requests that are ready + not SG_IO owned */
-		if ((1 == resp->done) && (!resp->sg_io_owned) &&
-		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
-			resp->done = 2;	/* guard against other readers */
-			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
-			return resp;
-		}
-	}
-	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
-	return NULL;
-}
-
 /* always adds to end of list */
 static Sg_request *
 sg_add_request(Sg_fd * sfp)