[RFC 3/4] nbd: Create helper functions for ioctls

From: Markus Pargmann
Date: Tue Jan 13 2015 - 08:45:22 EST


This patch prepares the nbd code for the nbd-root device patch. It
moves the ioctl code into separate functions so they can be called
directly. The patch creates nbd_set_total_size(), nbd_set_blksize(),
nbd_set_sock() and nbd_set_timeout().

Signed-off-by: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
---
drivers/block/nbd.c | 79 ++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 57 insertions(+), 22 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 0ff6ebbec252..11f7644be111 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -596,6 +596,55 @@ static void do_nbd_request(struct request_queue *q)
}
}

+/*
+ * Call with tx_lock held
+ */
+static void nbd_set_total_size(struct block_device *bdev,
+ struct nbd_device *nbd, size_t size)
+{
+ nbd->bytesize = size;
+ bdev->bd_inode->i_size = size;
+ set_blocksize(bdev, nbd->blksize);
+ set_capacity(nbd->disk, size >> 9);
+}
+
+/*
+ * Call with tx_lock held
+ */
+static void nbd_set_blksize(struct block_device *bdev, struct nbd_device *nbd,
+ size_t blksize)
+{
+ u64 new_bytesize;
+
+ nbd->blksize = blksize;
+ bdev->bd_inode->i_size = nbd->bytesize;
+ set_blocksize(bdev, nbd->blksize);
+
+ new_bytesize = nbd->bytesize & ~(nbd->blksize-1);
+ if (new_bytesize != nbd->bytesize)
+ nbd_set_total_size(bdev, nbd, new_bytesize);
+}
+
+/*
+ * Call with tx_lock held
+ */
+static void nbd_set_sock(struct block_device *bdev, struct nbd_device *nbd,
+ struct socket *sock)
+{
+ nbd->sock = sock;
+ if (max_part > 0)
+ bdev->bd_invalidated = 1;
+ nbd->disconnect = 0; /* we're connected now */
+}
+
+/*
+ * Call with tx_lock held
+ */
+static void nbd_set_timeout(struct nbd_device *nbd, int timeout)
+{
+ nbd->xmit_timeout = timeout * HZ;
+}
+
static int nbd_connection_start(struct block_device *bdev,
struct nbd_device *nbd)
{
@@ -733,33 +782,22 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
if (nbd->sock)
return -EBUSY;
sock = sockfd_lookup(arg, &err);
- if (sock) {
- nbd->sock = sock;
- if (max_part > 0)
- bdev->bd_invalidated = 1;
- nbd->disconnect = 0; /* we're connected now */
- return 0;
- }
- return -EINVAL;
+ if (!sock)
+ return -EINVAL;
+
+ nbd_set_sock(bdev, nbd, sock);
}

case NBD_SET_BLKSIZE:
- nbd->blksize = arg;
- nbd->bytesize &= ~(nbd->blksize-1);
- bdev->bd_inode->i_size = nbd->bytesize;
- set_blocksize(bdev, nbd->blksize);
- set_capacity(nbd->disk, nbd->bytesize >> 9);
+ nbd_set_blksize(bdev, nbd, arg);
return 0;

case NBD_SET_SIZE:
- nbd->bytesize = arg & ~(nbd->blksize-1);
- bdev->bd_inode->i_size = nbd->bytesize;
- set_blocksize(bdev, nbd->blksize);
- set_capacity(nbd->disk, nbd->bytesize >> 9);
+ nbd_set_total_size(bdev, nbd, arg & ~(nbd->blksize-1));
return 0;

case NBD_SET_TIMEOUT:
- nbd->xmit_timeout = arg * HZ;
+ nbd_set_timeout(nbd, arg);
return 0;

case NBD_SET_FLAGS:
@@ -767,10 +805,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
return 0;

case NBD_SET_SIZE_BLOCKS:
- nbd->bytesize = ((u64) arg) * nbd->blksize;
- bdev->bd_inode->i_size = nbd->bytesize;
- set_blocksize(bdev, nbd->blksize);
- set_capacity(nbd->disk, nbd->bytesize >> 9);
+ nbd_set_total_size(bdev, nbd, ((u64)arg) * nbd->blksize);
return 0;

case NBD_DO_IT:
--
2.1.4

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