allow userspace to modify scsi command filter on per device basis
This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.
Original patch from Peter Jones.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/bsg.c b/block/bsg.c
index f0b7cd3..439940c 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -44,11 +44,12 @@
char name[BUS_ID_SIZE];
int max_queue;
unsigned long flags;
+ struct blk_scsi_cmd_filter *cmd_filter;
+ mode_t *f_mode;
};
enum {
BSG_F_BLOCK = 1,
- BSG_F_WRITE_PERM = 2,
};
#define BSG_DEFAULT_CMDS 64
@@ -172,7 +173,7 @@
}
static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
- struct sg_io_v4 *hdr, int has_write_perm)
+ struct sg_io_v4 *hdr, struct bsg_device *bd)
{
if (hdr->request_len > BLK_MAX_CDB) {
rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
@@ -185,7 +186,8 @@
return -EFAULT;
if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
- if (blk_verify_command(rq->cmd, has_write_perm))
+ if (blk_cmd_filter_verify_command(bd->cmd_filter, rq->cmd,
+ bd->f_mode))
return -EPERM;
} else if (!capable(CAP_SYS_RAWIO))
return -EPERM;
@@ -263,8 +265,7 @@
rq = blk_get_request(q, rw, GFP_KERNEL);
if (!rq)
return ERR_PTR(-ENOMEM);
- ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
- &bd->flags));
+ ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd);
if (ret)
goto out;
@@ -566,12 +567,23 @@
set_bit(BSG_F_BLOCK, &bd->flags);
}
-static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file)
+static void bsg_set_cmd_filter(struct bsg_device *bd,
+ struct file *file)
{
- if (file->f_mode & FMODE_WRITE)
- set_bit(BSG_F_WRITE_PERM, &bd->flags);
- else
- clear_bit(BSG_F_WRITE_PERM, &bd->flags);
+ struct inode *inode;
+ struct gendisk *disk;
+
+ if (!file)
+ return;
+
+ inode = file->f_dentry->d_inode;
+ if (!inode)
+ return;
+
+ disk = inode->i_bdev->bd_disk;
+
+ bd->cmd_filter = &disk->cmd_filter;
+ bd->f_mode = &file->f_mode;
}
/*
@@ -595,6 +607,8 @@
dprintk("%s: read %Zd bytes\n", bd->name, count);
bsg_set_block(bd, file);
+ bsg_set_cmd_filter(bd, file);
+
bytes_read = 0;
ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
*ppos = bytes_read;
@@ -668,7 +682,7 @@
dprintk("%s: write %Zd bytes\n", bd->name, count);
bsg_set_block(bd, file);
- bsg_set_write_perm(bd, file);
+ bsg_set_cmd_filter(bd, file);
bytes_written = 0;
ret = __bsg_write(bd, buf, count, &bytes_written);
@@ -771,7 +785,9 @@
}
bd->queue = rq;
+
bsg_set_block(bd, file);
+ bsg_set_cmd_filter(bd, file);
atomic_set(&bd->ref_count, 1);
mutex_lock(&bsg_mutex);
