[PATCH 2/2] smb: client: retry compound request without reusing lease

[Paulo Alcantara]

meetakshisetiyaoss at gmail.com writes:

> From: Meetakshi Setiya <msetiya at microsoft.com>
>
> There is a shortcoming in the current implementation of the file
> lease mechanism exposed when the lease keys were attempted to be reused
> for unlink, rename and set_path_size operations for a client. As per
> MS-SMB2, lease keys are associated with the file name. Linux cifs client
> maintains lease keys with the inode. If the file has any hardlinks,
> it is possible that the lease for a file be wrongly reused for an
> operation on the hardlink or vice versa. In these cases, the mentioned
> compound operations fail with STATUS_INVALID_PARAMETER.
> This patch adds a fallback to the old mechanism of not sending any
> lease with these compound operations if the request with lease key fails
> with STATUS_INVALID_PARAMETER. Resending the same request without lease
> key should not hurt any functionality, but might impact performance
> especially in cases where the error is not because of the usage of wrong
> lease key and we might end up doing an extra roundtrip.

What's the problem with checking ->i_nlink to decide whether reusing
lease key?