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authorDoron Roberts-Kedes <doronrk@fb.com>2018-06-15 14:05:32 -0700
committerJens Axboe <axboe@kernel.dk>2018-06-20 19:10:06 -0600
commit08ba91ee6e2c1c08d3f0648f978cbb5dbf3491d8 (patch)
tree2c50d118291ce0b1a2c0a9f58f97f7defab7a33c /drivers/block/nbd.c
parentce042c183bcb94eb2919e8036473a1fc203420f9 (diff)
nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.
If NBD_DISCONNECT_ON_CLOSE is set on a device, then the driver will issue a disconnect from nbd_release if the device has no remaining bdev->bd_openers. Fix ret val so reconfigure with only setting the flag succeeds. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/nbd.c')
-rw-r--r--drivers/block/nbd.c42
1 files changed, 34 insertions, 8 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 3b7083b8ecbb..74a05561b620 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -76,6 +76,7 @@ struct link_dead_args {
#define NBD_HAS_CONFIG_REF 4
#define NBD_BOUND 5
#define NBD_DESTROY_ON_DISCONNECT 6
+#define NBD_DISCONNECT_ON_CLOSE 7
struct nbd_config {
u32 flags;
@@ -138,6 +139,7 @@ static void nbd_config_put(struct nbd_device *nbd);
static void nbd_connect_reply(struct genl_info *info, int index);
static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info);
static void nbd_dead_link_work(struct work_struct *work);
+static void nbd_disconnect_and_put(struct nbd_device *nbd);
static inline struct device *nbd_to_dev(struct nbd_device *nbd)
{
@@ -1305,6 +1307,12 @@ out:
static void nbd_release(struct gendisk *disk, fmode_t mode)
{
struct nbd_device *nbd = disk->private_data;
+ struct block_device *bdev = bdget_disk(disk, 0);
+
+ if (test_bit(NBD_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
+ bdev->bd_openers == 0)
+ nbd_disconnect_and_put(nbd);
+
nbd_config_put(nbd);
nbd_put(nbd);
}
@@ -1705,6 +1713,10 @@ again:
&config->runtime_flags);
put_dev = true;
}
+ if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
+ set_bit(NBD_DISCONNECT_ON_CLOSE,
+ &config->runtime_flags);
+ }
}
if (info->attrs[NBD_ATTR_SOCKETS]) {
@@ -1749,6 +1761,17 @@ out:
return ret;
}
+static void nbd_disconnect_and_put(struct nbd_device *nbd)
+{
+ mutex_lock(&nbd->config_lock);
+ nbd_disconnect(nbd);
+ nbd_clear_sock(nbd);
+ mutex_unlock(&nbd->config_lock);
+ if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
+ &nbd->config->runtime_flags))
+ nbd_config_put(nbd);
+}
+
static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
{
struct nbd_device *nbd;
@@ -1781,13 +1804,7 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
nbd_put(nbd);
return 0;
}
- mutex_lock(&nbd->config_lock);
- nbd_disconnect(nbd);
- nbd_clear_sock(nbd);
- mutex_unlock(&nbd->config_lock);
- if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
- &nbd->config->runtime_flags))
- nbd_config_put(nbd);
+ nbd_disconnect_and_put(nbd);
nbd_config_put(nbd);
nbd_put(nbd);
return 0;
@@ -1798,7 +1815,7 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
struct nbd_device *nbd = NULL;
struct nbd_config *config;
int index;
- int ret = -EINVAL;
+ int ret = 0;
bool put_dev = false;
if (!netlink_capable(skb, CAP_SYS_ADMIN))
@@ -1838,6 +1855,7 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
!nbd->task_recv) {
dev_err(nbd_to_dev(nbd),
"not configured, cannot reconfigure\n");
+ ret = -EINVAL;
goto out;
}
@@ -1862,6 +1880,14 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
&config->runtime_flags))
refcount_inc(&nbd->refs);
}
+
+ if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
+ set_bit(NBD_DISCONNECT_ON_CLOSE,
+ &config->runtime_flags);
+ } else {
+ clear_bit(NBD_DISCONNECT_ON_CLOSE,
+ &config->runtime_flags);
+ }
}
if (info->attrs[NBD_ATTR_SOCKETS]) {