From: Al Viro <viro@zeniv.linux.org.uk>
To: NeilBrown <neilb@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
"Tobin C. Harding" <tobin@kernel.org>,
Mauro Carvalho Chehab <mchehab@s-opensource.com>,
Randy Dunlap <rdunlap@infradead.org>,
linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 00/24] Convert vfs.txt to vfs.rst
Date: Wed, 3 Apr 2019 02:44:14 +0100 [thread overview]
Message-ID: <20190403014414.GN2217@ZenIV.linux.org.uk> (raw)
In-Reply-To: <87d0m32989.fsf@notabene.neil.brown.name>
On Wed, Apr 03, 2019 at 12:00:54PM +1100, NeilBrown wrote:
> I would find it useful if the documentation said something about why
> this API exists at all. As you say, it cannot change the dentry - so
> what is it expected to do.
*shrug*
It tell filesystem that this dentry is going away now.
> I had a look at the two in-tree users and my guess is that it can be
> useful if the filesystem caches some other information which would be
> invalidated by a dentry being removed.
> I *think* cephfs has a flag which records if "All entries in a directory
> are currently in the dcache". When a dentry is pruned, that flag needs
> to be cleared.
>
> i.e. ->d_prune allows a filesystem to maintain summary state about what
> is currently in the dcache.
For one thing... Or, if you keep a (non-counting) reference to that
dentry, this tells you to forget it, etc.
I can think of other uses; it's really just telling the fs that this
is becoming an ex-parrot.
prev parent reply other threads:[~2019-04-03 1:44 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-27 5:16 [PATCH v3 00/24] Convert vfs.txt to vfs.rst Tobin C. Harding
2019-03-27 5:16 ` [PATCH v3 01/24] vfs: Remove trailing whitespace Tobin C. Harding
2019-03-27 5:16 ` [PATCH v3 02/24] vfs: Clean up VFS data structure declarations Tobin C. Harding
2019-03-27 5:16 ` [PATCH v3 03/24] fs: Update function docstring for dio_complete() Tobin C. Harding
2019-03-27 5:16 ` [PATCH v3 04/24] fs: Add docstrings to exported functions Tobin C. Harding
2019-03-27 5:16 ` [PATCH v3 05/24] fs: Guard unusual text with backticks Tobin C. Harding
2019-03-27 5:16 ` [PATCH v3 06/24] fs: Update function docstring for simple_write_end() Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 07/24] fs: Fix function docstring for posix_acl_update_mode() Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 08/24] dcache: Remove trailing whitespace Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 09/24] dcache: Fix i.e. usage in coments Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 10/24] dcache: Fix e.g. usage in comment Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 11/24] dcache: Fix docstring comment for d_drop() Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 12/24] dcache: Fix non-docstring comments Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 13/24] dcache: Clean up function docstrings Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 14/24] dcache: Clean up function docstring members Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 15/24] docs: filesystems: vfs: Remove space before tab Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 16/24] docs: filesystems: vfs: Use uniform space after period Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 17/24] docs: filesystems: vfs: Use 72 character column width Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 18/24] docs: filesystems: vfs: Use uniform spacing around headings Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 19/24] docs: filesystems: vfs: Use correct initial heading Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 20/24] docs: filesystems: vfs: Use SPDX identifier Tobin C. Harding
2019-04-01 5:43 ` Mukesh Ojha
2019-03-27 5:17 ` [PATCH v3 21/24] docs: filesystems: vfs: Fix pre-amble indentation Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 22/24] fs: Copy documentation to struct declarations Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 23/24] dcache: Copy documentation to struct declaration Tobin C. Harding
2019-03-27 5:17 ` [PATCH v3 24/24] docs: Convert vfs.txt to reStructuredText format Tobin C. Harding
2019-03-27 5:24 ` [PATCH v3 00/24] Convert vfs.txt to vfs.rst Joe Perches
2019-03-27 6:26 ` Tobin C. Harding
2019-04-02 15:49 ` Jonathan Corbet
2019-04-02 16:48 ` Al Viro
2019-04-02 17:54 ` Al Viro
2019-04-02 19:08 ` Al Viro
2019-04-02 23:36 ` Ian Kent
2019-04-02 23:56 ` Ian Kent
2019-04-03 0:55 ` NeilBrown
2019-04-03 19:35 ` Al Viro
2019-04-04 6:30 ` Ian Kent
2019-04-03 23:28 ` Ian Kent
2019-04-02 19:25 ` Tobin C. Harding
2019-04-03 19:47 ` Al Viro
2019-04-03 20:59 ` Tobin C. Harding
2019-04-03 1:00 ` NeilBrown
2019-04-03 1:44 ` Al Viro [this message]
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