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authorPaul Clements <paul.clements@steeleye.com>2012-10-05 00:16:15 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-05 18:05:23 (GMT)
commit2f012508880f8037590372c24ca6e8b6af8fffb6 (patch)
tree3921d2b8d00cf47503d30455e2b4df180cc13d11
parentde74e00a965177e8a0d44af0ba31971b80f2bf3f (diff)
downloadlinux-2f012508880f8037590372c24ca6e8b6af8fffb6.tar.xz
nbd: add set flags ioctl
Add a set-flags ioctl, allowing various option flags to be set on an nbd device. This allows the nbd-client to set the device flags (to enable read-only mode, or enable discard support, etc.). Flags are typically specified by the nbd-server. During the negotiation phase of the nbd connection, the server sends its flags to the client. The client then uses NBD_SET_FLAGS to inform the kernel of the options. Also included is a one-line fix to debug output for the set-timeout ioctl. Signed-off-by: Paul Clements <paul.clements@steeleye.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/block/nbd.c8
-rw-r--r--include/linux/nbd.h9
2 files changed, 12 insertions, 5 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 0c03411..68fe751 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -78,6 +78,8 @@ static const char *ioctl_cmd_to_ascii(int cmd)
case NBD_SET_SOCK: return "set-sock";
case NBD_SET_BLKSIZE: return "set-blksize";
case NBD_SET_SIZE: return "set-size";
+ case NBD_SET_TIMEOUT: return "set-timeout";
+ case NBD_SET_FLAGS: return "set-flags";
case NBD_DO_IT: return "do-it";
case NBD_CLEAR_SOCK: return "clear-sock";
case NBD_CLEAR_QUE: return "clear-que";
@@ -468,7 +470,7 @@ static void nbd_handle_req(struct nbd_device *nbd, struct request *req)
nbd_cmd(req) = NBD_CMD_READ;
if (rq_data_dir(req) == WRITE) {
nbd_cmd(req) = NBD_CMD_WRITE;
- if (nbd->flags & NBD_READ_ONLY) {
+ if (nbd->flags & NBD_FLAG_READ_ONLY) {
dev_err(disk_to_dev(nbd->disk),
"Write on read-only\n");
goto error_out;
@@ -651,6 +653,10 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
nbd->xmit_timeout = arg * HZ;
return 0;
+ case NBD_SET_FLAGS:
+ nbd->flags = arg;
+ return 0;
+
case NBD_SET_SIZE_BLOCKS:
nbd->bytesize = ((u64) arg) * nbd->blksize;
bdev->bd_inode->i_size = nbd->bytesize;
diff --git a/include/linux/nbd.h b/include/linux/nbd.h
index d146ca1..4b8ed5a 100644
--- a/include/linux/nbd.h
+++ b/include/linux/nbd.h
@@ -27,6 +27,7 @@
#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
#define NBD_DISCONNECT _IO( 0xab, 8 )
#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
+#define NBD_SET_FLAGS _IO( 0xab, 10)
enum {
NBD_CMD_READ = 0,
@@ -34,6 +35,10 @@ enum {
NBD_CMD_DISC = 2
};
+/* values for flags field */
+#define NBD_FLAG_HAS_FLAGS (1 << 0) /* nbd-server supports flags */
+#define NBD_FLAG_READ_ONLY (1 << 1) /* device is read-only */
+
#define nbd_cmd(req) ((req)->cmd[0])
/* userspace doesn't need the nbd_device structure */
@@ -42,10 +47,6 @@ enum {
#include <linux/wait.h>
#include <linux/mutex.h>
-/* values for flags field */
-#define NBD_READ_ONLY 0x0001
-#define NBD_WRITE_NOCHK 0x0002
-
struct request;
struct nbd_device {