Re: [PATCH v9 2/6] fs, mm: pass fd to ->mmap_validate()
From: Dan Williams <hidden>
Date: 2017-10-12 01:28:32
Also in:
linux-fsdevel, linux-mm, linux-xfs, nvdimm
On Wed, Oct 11, 2017 at 6:21 PM, Al Viro [off-list ref] wrote:
On Wed, Oct 11, 2017 at 05:47:18PM -0700, Dan Williams wrote:quoted
The MAP_DIRECT mechanism for mmap intends to use a file lease to prevent block map changes while the file is mapped. It requires the fd to setup an fasync_struct for signalling lease break events to the lease holder.*UGH* That looks like one hell of a bad API. You are not even guaranteed that descriptor will remain be still open by the time you pass it down to your helper, nevermind the moment when event actually happens...
What am I missing, fcntl(F_SETLEASE) seems to follow a similar pattern?