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block: move cmdfilter from gendisk to request_queue

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cmd_filter works only for the block layer SG_IO with SCSI block
devices. It breaks scsi/sg.c, bsg, and the block layer SG_IO with SCSI
character devices (such as st). We hit a kernel crash with them.

The problem is that cmd_filter code accesses to gendisk (having struct
blk_scsi_cmd_filter) via inode->i_bdev->bd_disk. It works for only
SCSI block device files. With character device files, inode->i_bdev
leads you to struct cdev. inode->i_bdev->bd_disk->blk_scsi_cmd_filter
isn't safe.

SCSI ULDs don't expose gendisk; they keep it private. bsg needs to be
independent on any protocols. We shouldn't change ULDs to expose their
gendisk.

This patch moves struct blk_scsi_cmd_filter from gendisk to
request_queue, a common object, which eveyone can access to.

The user interface doesn't change; users can change the filters via
/sys/block/. gendisk has a pointer to request_queue so the cmd_filter
code accesses to struct blk_scsi_cmd_filter.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
FUJITA Tomonori
2008-08-16 14:10:05 +09:00
committed by Jens Axboe
parent 1941246dd9
commit abf5439370
7 changed files with 132 additions and 163 deletions
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11
drivers/scsi/sg.c
View File

@@ -641,6 +641,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
unsigned char cmnd[MAX_COMMAND_SIZE];
int timeout;
unsigned long ul_timeout;
struct request_queue *q;
if (count < SZ_SG_IO_HDR)
return -EINVAL;
@@ -689,7 +690,9 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
sg_remove_request(sfp, srp);
return -EFAULT;
}
if (read_only && !blk_verify_command(file, cmnd)) {
q = sfp->parentdp->device->request_queue;
if (read_only && blk_verify_command(&q->cmd_filter, cmnd,
file->f_mode & FMODE_WRITE)) {
sg_remove_request(sfp, srp);
return -EPERM;
}
@@ -793,6 +796,7 @@ sg_ioctl(struct inode *inode, struct file *filp,
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
sdp->disk->disk_name, (int) cmd_in));
read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
@@ -1057,11 +1061,14 @@ sg_ioctl(struct inode *inode, struct file *filp,
return -ENODEV;
if (read_only) {
unsigned char opcode = WRITE_6;
struct request_queue *q = sdp->device->request_queue;
Scsi_Ioctl_Command __user *siocp = p;
if (copy_from_user(&opcode, siocp->data, 1))
return -EFAULT;
if (!blk_verify_command(filp, &opcode))
if (blk_verify_command(&q->cmd_filter,
&opcode,
filp->f_mode & FMODE_WRITE))
return -EPERM;
}
return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);