korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 04:18:39 +08:00
Code Issues Packages Projects Releases Wiki Activity

nbd: Create size change events for userspace

Browse Source 
The userspace needs to know when nbd devices are ready for use.
Currently no events are created for the userspace which doesn't work for
systemd.

See the discussion here: https://github.com/systemd/systemd/pull/358

This patch uses a central point to setup the nbd-internal sizes. A ioctl
to set a size does not lead to a visible size change. The size of the
block device will be kept at 0 until nbd is connected. As soon as it
connects, the size will be changed to the real value and a uevent is
created. When disconnecting, the blockdevice is set to 0 size and
another uevent is generated.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
This commit is contained in:
Markus Pargmann 2015-07-27 07:36:49 +02:00
parent da6ccaaa79
commit 37091fdd83
1 changed files with 58 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

79
drivers/block/nbd.c
View File

@ -100,6 +100,11 @@ static inline struct device *nbd_to_dev(struct nbd_device *nbd)
return disk_to_dev(nbd->disk);
}
static bool nbd_is_connected(struct nbd_device *nbd)
{
return !!nbd->task_recv;
}
static const char *nbdcmd_to_ascii(int cmd)
{
switch (cmd) {
@ -112,6 +117,42 @@ static const char *nbdcmd_to_ascii(int cmd)
return "invalid";
}
static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev)
{
bdev->bd_inode->i_size = 0;
set_capacity(nbd->disk, 0);
kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
return 0;
}
static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev)
{
if (!nbd_is_connected(nbd))
return;
bdev->bd_inode->i_size = nbd->bytesize;
set_capacity(nbd->disk, nbd->bytesize >> 9);
kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
}
static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev,
int blocksize, int nr_blocks)
{
int ret;
ret = set_blocksize(bdev, blocksize);
if (ret)
return ret;
nbd->blksize = blocksize;
nbd->bytesize = (loff_t)blocksize * (loff_t)nr_blocks;
nbd_size_update(nbd, bdev);
return 0;
}
static void nbd_end_request(struct nbd_device *nbd, struct request *req)
{
int error = req->errors ? -EIO : 0;
@ -401,7 +442,7 @@ static struct device_attribute pid_attr = {
.show = pid_show,
};
static int nbd_thread_recv(struct nbd_device *nbd)
static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev)
{
struct request *req;
int ret;
@ -421,6 +462,8 @@ static int nbd_thread_recv(struct nbd_device *nbd)
return ret;
}
nbd_size_update(nbd, bdev);
while (1) {
req = nbd_read_stat(nbd);
if (IS_ERR(req)) {
@ -431,6 +474,8 @@ static int nbd_thread_recv(struct nbd_device *nbd)
nbd_end_request(nbd, req);
}
nbd_size_clear(nbd, bdev);
device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
nbd->task_recv = NULL;
@ -707,20 +752,19 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
return err;
}
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);
return 0;
case NBD_SET_BLKSIZE: {
loff_t bsize = nbd->bytesize;
do_div(bsize, arg);
return nbd_size_set(nbd, bdev, arg, bsize);
}
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);
return 0;
return nbd_size_set(nbd, bdev, nbd->blksize,
arg / nbd->blksize);
case NBD_SET_SIZE_BLOCKS:
return nbd_size_set(nbd, bdev, nbd->blksize, arg);
case NBD_SET_TIMEOUT:
nbd->xmit_timeout = arg * HZ;
@ -736,13 +780,6 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
nbd->flags = arg;
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);
return 0;
case NBD_DO_IT: {
struct task_struct *thread;
int error;
@ -764,7 +801,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
}
nbd_dev_dbg_init(nbd);
error = nbd_thread_recv(nbd);
error = nbd_thread_recv(nbd, bdev);
nbd_dev_dbg_close(nbd);
kthread_stop(thread);