From 2f012508880f8037590372c24ca6e8b6af8fffb6 Mon Sep 17 00:00:00 2001 From: Paul Clements Date: Thu, 4 Oct 2012 17:16:15 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/nbd.c | 8 +++++++- include/linux/nbd.h | 9 +++++---- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 0c03411c59eb..68fe7514413d 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 d146ca10c0f5..4b8ed5a1cfb0 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 #include -/* values for flags field */ -#define NBD_READ_ONLY 0x0001 -#define NBD_WRITE_NOCHK 0x0002 - struct request; struct nbd_device { -- 2.34.1