[BUG] BlobClient.UploadAsync(Stream content, bool overwrite) deadlocks if the stream is not rewinded

Consider the following code, where stream is valid and previously created, and pos is a number larger than 0 and less than or equal to the stream’s size:

stream.Seek(pos, SeekOrigin.Begin);

// Write to Azure Blob Storage
BlobClient blobClient = blobContainerClient.GetBlobClient("MyBlob1");
await blobClient.UploadAsync(stream, true);

If this is run, the code will deadlock while awaiting. The Tasks view in Visual Studio shows multiple tasks running:

Upon analyzing, each task N is waiting for task N-1, with the exception of:

• 36 (waiting on 161)
• 141 (waiting on 173)
• 168 (only scheduled, and waiting to run)

The call stack, while breaking into during the stall, is below:

Using try/catch around the async call doesn’t result in anything throwing.

Should the position in the stream be 0, the call completes as expected.

Environment:

• Name and version of the Library package used: Azure.Storage.Blobs 12.4.4
• Hosting platform or OS and .NET runtime version (dotnet --info output for .NET Core projects): Windows 10 .NET Core 3.1.0
• IDE and version : Visual Studio 16.5.0 Preview 2

[pakrym]

@kasobol-msft had found the source of the issue already, it’s because https://github.com/Azure/azure-sdk-for-net/blob/9118e1d66bee5db546c93a01669c9d66e57a69f9/sdk/storage/Azure.Storage.Blobs/src/BlockBlobClient.cs#L723 doesn’t take Position into account when setting a Content-Lenght header value. Fixing math there and in similar spots would fix the bug.

[amnguye]

Hi, please provide reproduction of the problem you are running into using 12.10.0 with as much details as possible so we can resolve it.

Then we can determine if we need to reopen this issue or open a different one.