Re: [PATCH 15/15] parallel lookups: actual switch to rwsem

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From	Al Viro <viro@ZenIV.linux.org.uk>
Newsgroups	linux.kernel
Subject	Re: [PATCH 15/15] parallel lookups: actual switch to rwsem
Date	Sat, 16 Apr 2016 05:40:02 +0200
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On Fri, Apr 15, 2016 at 09:02:06PM -0600, Andreas Dilger wrote:

> Wouldn't it make sense to have helpers like "inode_read_lock(inode)" or similar,
> so that it is consistent with other parts of the code and easier to find?
> It's a bit strange to have the filesystems use "inode_lock()" and some places
> here use "inode_lock_nested()", but other places use up_read() and down_read()
> directly on &inode->i_rwsem.  That would also simplify delegating the directory
> locking to the filesystems in the future.

FWIW, my preference would be inode_lock_shared(), but that's bikeshedding;
seeing that we have very few callers at the moment *and* there's the missing
down_write_killable() stuff...  This patch will obviously be reworked and
it's small enough to be understandable, open-coding or not.

Thread

[PATCHSET][RFC][CFT] parallel lookups Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 03:00 +0200
  [PATCH 01/15] security_d_instantiate(): move to the point prior to attaching dentry to inode Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 03:00 +0200
  [PATCH 09/15] lookup_slow(): bugger off on IS_DEADDIR() from the very beginning Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 03:00 +0200
  [PATCH 14/15] parallel lookups machinery, part 4 (and last) Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 03:00 +0200
  [PATCH 15/15] parallel lookups: actual switch to rwsem Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 03:00 +0200
    Re: [PATCH 15/15] parallel lookups: actual switch to rwsem Andreas Dilger <adilger@dilger.ca> - 2016-04-16 05:10 +0200
      Re: [PATCH 15/15] parallel lookups: actual switch to rwsem Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 05:40 +0200
  Re: [PATCHSET][RFC][CFT] parallel lookups Andreas Dilger <adilger@dilger.ca> - 2016-04-16 05:10 +0200
    Re: [PATCHSET][RFC][CFT] parallel lookups Al Viro <viro@ZenIV.linux.org.uk> - 2016-04-16 05:30 +0200

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