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| author | Manuel Bentele | 2020-11-09 07:16:07 +0100 |
|---|---|---|
| committer | Manuel Bentele | 2020-11-09 07:16:07 +0100 |
| commit | db5a93a43fea2aa3c3bbaf8c48d238e60d834676 (patch) | |
| tree | 83f0098e32e5b3641567480bea07ccdc978d61fb | |
| parent | [KERNEL]: change probing logic to select first available server (diff) | |
| download | dnbd3-db5a93a43fea2aa3c3bbaf8c48d238e60d834676.tar.gz dnbd3-db5a93a43fea2aa3c3bbaf8c48d238e60d834676.tar.xz dnbd3-db5a93a43fea2aa3c3bbaf8c48d238e60d834676.zip | |
[KERNEL] protect access to server list if alt server is added/removed
This patch locks the protecting spinlock of the DNBD3 device's new
server list. Otherwise a race condition between ioctl ADD_SRV/REM_SRV
(process context) and dnbd3 discover thread would be possible.
| -rw-r--r-- | src/kernel/blk.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/kernel/blk.c b/src/kernel/blk.c index afdeea8..7e043c0 100644 --- a/src/kernel/blk.c +++ b/src/kernel/blk.c @@ -39,6 +39,7 @@ static int dnbd3_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int struct request_queue *blk_queue = dev->disk->queue; char *imgname = NULL; dnbd3_ioctl_t *msg = NULL; + unsigned long irqflags; int i = 0; while (dev->disconnecting) { /* do nothing */ } @@ -193,9 +194,11 @@ static int dnbd3_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int } else { + spin_lock_irqsave(&dev->blk_lock, irqflags); memcpy(&dev->new_servers[dev->new_servers_num].host, &msg->hosts[0], sizeof(msg->hosts[0])); dev->new_servers[dev->new_servers_num].failures = (cmd == IOCTL_ADD_SRV ? 0 : 1); // 0 = ADD, 1 = REM ++dev->new_servers_num; + spin_unlock_irqrestore(&dev->blk_lock, irqflags); result = 0; } break; |