[dm-devel] [PATCH 5/6] libmultipath: simplify failed wwid code

[Martin Wilck]

On Thu, 2020-05-14 at 20:59 -0500, Benjamin Marzinski wrote:
> The (is|mark|unmark)_failed_wwid code is needlessly complicated.
> Locking a file is necssary if multiple processes could otherwise be
> writing to it at the same time. That is not the case with the
> failed_wwids files. They can simply be empty files in a
> directory.  Even
> with all the locking in place, two processes accessing or modifying a
> file at the same time will still race. And even without the locking,
> if
> two processes try to access or modify a file at the same time, they
> will
> both see a reasonable result, and will leave the files in a valid
> state
> afterwards.
> 
> Instead of doing all the locking work (which made it necessary to
> write
> a file, even just to check if a file existed), simply check for files
> with lstat(), create them with open(), and remove them with unlink().
> 
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>

With the follow-up (6/6):
Reviewed-by: Martin Wilck <mwilck at suse.com>

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