block: get rid of queue-private command filter

The initial patches to support this through sysfs export were broken
and have been if 0'ed out in any release. So lets just kill the code
and reclaim some space in struct request_queue, if anyone would later
like to fixup the sysfs bits, the git history can easily restore
the removed bits.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/Makefile

@@ -5,7 +5,7 @@
 obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
 			blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
 			blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
-			ioctl.o genhd.o scsi_ioctl.o cmd-filter.o
+			ioctl.o genhd.o scsi_ioctl.o
 
 obj-$(CONFIG_BLK_DEV_BSG)	+= bsg.o
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o

block/blk-core.c

@@ -595,8 +595,6 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
 
 	q->sg_reserved_size = INT_MAX;
 
-	blk_set_cmd_filter_defaults(&q->cmd_filter);
-
 	/*
 	 * all done
 	 */

block/bsg.c

@@ -186,7 +186,7 @@ static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
 		return -EFAULT;
 
 	if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
-		if (blk_verify_command(&q->cmd_filter, rq->cmd, has_write_perm))
+		if (blk_verify_command(rq->cmd, has_write_perm))
 			return -EPERM;
 	} else if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;

block/cmd-filter.c

-/*
- * Copyright 2004 Peter M. Jones <pjones@redhat.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public Licens
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
- *
- */
-
-#include <linux/list.h>
-#include <linux/genhd.h>
-#include <linux/spinlock.h>
-#include <linux/capability.h>
-#include <linux/bitops.h>
-#include <linux/blkdev.h>
-
-#include <scsi/scsi.h>
-#include <linux/cdrom.h>
-
-int blk_verify_command(struct blk_cmd_filter *filter,
-		       unsigned char *cmd, fmode_t has_write_perm)
-{
-	/* root can do any command. */
-	if (capable(CAP_SYS_RAWIO))
-		return 0;
-
-	/* if there's no filter set, assume we're filtering everything out */
-	if (!filter)
-		return -EPERM;
-
-	/* Anybody who can open the device can do a read-safe command */
-	if (test_bit(cmd[0], filter->read_ok))
-		return 0;
-
-	/* Write-safe commands require a writable open */
-	if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
-		return 0;
-
-	return -EPERM;
-}
-EXPORT_SYMBOL(blk_verify_command);
-
-#if 0
-/* and now, the sysfs stuff */
-static ssize_t rcf_cmds_show(struct blk_cmd_filter *filter, char *page,
-			     int rw)
-{
-	char *npage = page;
-	unsigned long *okbits;
-	int i;
-
-	if (rw == READ)
-		okbits = filter->read_ok;
-	else
-		okbits = filter->write_ok;
-
-	for (i = 0; i < BLK_SCSI_MAX_CMDS; i++) {
-		if (test_bit(i, okbits)) {
-			npage += sprintf(npage, "0x%02x", i);
-			if (i < BLK_SCSI_MAX_CMDS - 1)
-				sprintf(npage++, " ");
-		}
-	}
-
-	if (npage != page)
-		npage += sprintf(npage, "\n");
-
-	return npage - page;
-}
-
-static ssize_t rcf_readcmds_show(struct blk_cmd_filter *filter, char *page)
-{
-	return rcf_cmds_show(filter, page, READ);
-}
-
-static ssize_t rcf_writecmds_show(struct blk_cmd_filter *filter,
-				 char *page)
-{
-	return rcf_cmds_show(filter, page, WRITE);
-}
-
-static ssize_t rcf_cmds_store(struct blk_cmd_filter *filter,
-			      const char *page, size_t count, int rw)
-{
-	unsigned long okbits[BLK_SCSI_CMD_PER_LONG], *target_okbits;
-	int cmd, set;
-	char *p, *status;
-
-	if (rw == READ) {
-		memcpy(&okbits, filter->read_ok, sizeof(okbits));
-		target_okbits = filter->read_ok;
-	} else {
-		memcpy(&okbits, filter->write_ok, sizeof(okbits));
-		target_okbits = filter->write_ok;
-	}
-
-	while ((p = strsep((char **)&page, " ")) != NULL) {
-		set = 1;
-
-		if (p[0] == '+') {
-			p++;
-		} else if (p[0] == '-') {
-			set = 0;
-			p++;
-		}
-
-		cmd = simple_strtol(p, &status, 16);
-
-		/* either of these cases means invalid input, so do nothing. */
-		if ((status == p) || cmd >= BLK_SCSI_MAX_CMDS)
-			return -EINVAL;
-
-		if (set)
-			__set_bit(cmd, okbits);
-		else
-			__clear_bit(cmd, okbits);
-	}
-
-	memcpy(target_okbits, okbits, sizeof(okbits));
-	return count;
-}
-
-static ssize_t rcf_readcmds_store(struct blk_cmd_filter *filter,
-				  const char *page, size_t count)
-{
-	return rcf_cmds_store(filter, page, count, READ);
-}
-
-static ssize_t rcf_writecmds_store(struct blk_cmd_filter *filter,
-				   const char *page, size_t count)
-{
-	return rcf_cmds_store(filter, page, count, WRITE);
-}
-
-struct rcf_sysfs_entry {
-	struct attribute attr;
-	ssize_t (*show)(struct blk_cmd_filter *, char *);
-	ssize_t (*store)(struct blk_cmd_filter *, const char *, size_t);
-};
-
-static struct rcf_sysfs_entry rcf_readcmds_entry = {
-	.attr = { .name = "read_table", .mode = S_IRUGO | S_IWUSR },
-	.show = rcf_readcmds_show,
-	.store = rcf_readcmds_store,
-};
-
-static struct rcf_sysfs_entry rcf_writecmds_entry = {
-	.attr = {.name = "write_table", .mode = S_IRUGO | S_IWUSR },
-	.show = rcf_writecmds_show,
-	.store = rcf_writecmds_store,
-};
-
-static struct attribute *default_attrs[] = {
-	&rcf_readcmds_entry.attr,
-	&rcf_writecmds_entry.attr,
-	NULL,
-};
-
-#define to_rcf(atr) container_of((atr), struct rcf_sysfs_entry, attr)
-
-static ssize_t
-rcf_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
-{
-	struct rcf_sysfs_entry *entry = to_rcf(attr);
-	struct blk_cmd_filter *filter;
-
-	filter = container_of(kobj, struct blk_cmd_filter, kobj);
-	if (entry->show)
-		return entry->show(filter, page);
-
-	return 0;
-}
-
-static ssize_t
-rcf_attr_store(struct kobject *kobj, struct attribute *attr,
-			const char *page, size_t length)
-{
-	struct rcf_sysfs_entry *entry = to_rcf(attr);
-	struct blk_cmd_filter *filter;
-
-	if (!capable(CAP_SYS_RAWIO))
-		return -EPERM;
-
-	if (!entry->store)
-		return -EINVAL;
-
-	filter = container_of(kobj, struct blk_cmd_filter, kobj);
-	return entry->store(filter, page, length);
-}
-
-static struct sysfs_ops rcf_sysfs_ops = {
-	.show = rcf_attr_show,
-	.store = rcf_attr_store,
-};
-
-static struct kobj_type rcf_ktype = {
-	.sysfs_ops = &rcf_sysfs_ops,
-	.default_attrs = default_attrs,
-};
-
-int blk_register_filter(struct gendisk *disk)
-{
-	int ret;
-	struct blk_cmd_filter *filter = &disk->queue->cmd_filter;
-
-	ret = kobject_init_and_add(&filter->kobj, &rcf_ktype,
-				   &disk_to_dev(disk)->kobj,
-				   "%s", "cmd_filter");
-	if (ret < 0)
-		return ret;
-
-	return 0;
-}
-EXPORT_SYMBOL(blk_register_filter);
-
-void blk_unregister_filter(struct gendisk *disk)
-{
-	struct blk_cmd_filter *filter = &disk->queue->cmd_filter;
-
-	kobject_put(&filter->kobj);
-}
-EXPORT_SYMBOL(blk_unregister_filter);
-#endif

block/scsi_ioctl.c

@@ -32,6 +32,11 @@
 #include <scsi/scsi_ioctl.h>
 #include <scsi/scsi_cmnd.h>
 
+struct blk_cmd_filter {
+	unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
+	unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
+} blk_default_cmd_filter;
+
 /* Command group 3 is reserved and should never be used.  */
 const unsigned char scsi_command_size_tbl[8] =
 {
@@ -105,7 +110,7 @@ static int sg_emulated_host(struct request_queue *q, int __user *p)
 	return put_user(1, p);
 }
 
-void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
+static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
 {
 	/* Basic read-only commands */
 	__set_bit(TEST_UNIT_READY, filter->read_ok);
@@ -187,14 +192,37 @@ void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
 	__set_bit(GPCMD_SET_STREAMING, filter->write_ok);
 	__set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
 }
-EXPORT_SYMBOL_GPL(blk_set_cmd_filter_defaults);
+
+int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
+{
+	struct blk_cmd_filter *filter = &blk_default_cmd_filter;
+
+	/* root can do any command. */
+	if (capable(CAP_SYS_RAWIO))
+		return 0;
+
+	/* if there's no filter set, assume we're filtering everything out */
+	if (!filter)
+		return -EPERM;
+
+	/* Anybody who can open the device can do a read-safe command */
+	if (test_bit(cmd[0], filter->read_ok))
+		return 0;
+
+	/* Write-safe commands require a writable open */
+	if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
+		return 0;
+
+	return -EPERM;
+}
+EXPORT_SYMBOL(blk_verify_command);
 
 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
 			     struct sg_io_hdr *hdr, fmode_t mode)
 {
 	if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
 		return -EFAULT;
-	if (blk_verify_command(&q->cmd_filter, rq->cmd, mode & FMODE_WRITE))
+	if (blk_verify_command(rq->cmd, mode & FMODE_WRITE))
 		return -EPERM;
 
 	/*
@@ -427,7 +455,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
 		goto error;
 
-	err = blk_verify_command(&q->cmd_filter, rq->cmd, mode & FMODE_WRITE);
+	err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
 	if (err)
 		goto error;
 
@@ -645,5 +673,10 @@ int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mod
 	blk_put_queue(q);
 	return err;
 }
-
 EXPORT_SYMBOL(scsi_cmd_ioctl);
+
+int __init blk_scsi_ioctl_init(void)
+{
+	blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
+	return 0;
+}

drivers/scsi/sg.c

@@ -210,13 +210,11 @@ static void sg_put_dev(Sg_device *sdp);
 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 {
 	struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
-	struct request_queue *q = sfp->parentdp->device->request_queue;
 
 	if (sfp->parentdp->device->type == TYPE_SCANNER)
 		return 0;
 
-	return blk_verify_command(&q->cmd_filter,
-				  cmd, filp->f_mode & FMODE_WRITE);
+	return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 }
 
 static int

include/linux/blkdev.h

@@ -301,12 +301,6 @@ struct blk_queue_tag {
 #define BLK_SCSI_MAX_CMDS	(256)
 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 
-struct blk_cmd_filter {
-	unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
-	unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
-	struct kobject kobj;
-};
-
 struct queue_limits {
 	unsigned long		bounce_pfn;
 	unsigned long		seg_boundary_mask;
@@ -445,7 +439,6 @@ struct request_queue
 #if defined(CONFIG_BLK_DEV_BSG)
 	struct bsg_class_device bsg_dev;
 #endif
-	struct blk_cmd_filter cmd_filter;
 };
 
 #define QUEUE_FLAG_CLUSTER	0	/* cluster several segments into 1 */
@@ -998,13 +991,7 @@ static inline int sb_issue_discard(struct super_block *sb,
 	return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
 }
 
-/*
-* command filter functions
-*/
-extern int blk_verify_command(struct blk_cmd_filter *filter,
-			      unsigned char *cmd, fmode_t has_write_perm);
-extern void blk_unregister_filter(struct gendisk *disk);
-extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
+extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 
 #define MAX_PHYS_SEGMENTS 128
 #define MAX_HW_SEGMENTS 128