From: Al Viro <viro@zeniv.linux.org.uk>
To: NeilBrown <neilb@suse.de>
Cc: Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 02/11] VFS: add _shared versions of the various directory modifying inode_operations
Date: Mon, 23 Dec 2024 05:08:29 +0000 [thread overview]
Message-ID: <20241223050829.GJ1977892@ZenIV> (raw)
In-Reply-To: <20241220030830.272429-3-neilb@suse.de>
On Fri, Dec 20, 2024 at 01:54:20PM +1100, NeilBrown wrote:
> i_rwsem *may* be held exclusively or *may* be held shared, in which case
> an exclusive lock will be held on the dentry - provided by a later
> patch.
>
> This will allow a graceful transition from exclusive to shared locking
> for directory updates.
> +A "mixed" lock means that either that i_rwsem on the directory is held
> +exclusively, or it is held as a shared lock, and an exclusive lock is held
> +on the dentry in that directory.
... it also means that ->d_parent and ->d_name are completely unstable.
Yes, really - have rmdir victim moved around on server, then look it up
in a new place and you'll get __d_unalias() move the existing dentry
to new location right under you.
next prev parent reply other threads:[~2024-12-23 5:08 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-20 2:54 [PATCH 00/11 RFC] Allow concurrent changes in a directory NeilBrown
2024-12-20 2:54 ` [PATCH 01/11] VFS: introduce vfs_mkdir_return() NeilBrown
2024-12-23 5:04 ` Al Viro
2024-12-23 7:26 ` NeilBrown
2024-12-20 2:54 ` [PATCH 02/11] VFS: add _shared versions of the various directory modifying inode_operations NeilBrown
2024-12-23 5:08 ` Al Viro [this message]
2024-12-20 2:54 ` [PATCH 03/11] VFS: use global wait-queue table for d_alloc_parallel() NeilBrown
2024-12-20 2:54 ` [PATCH 04/11] VFS: use d_alloc_parallel() in lookup_one_qstr_excl() NeilBrown
2024-12-20 2:54 ` [PATCH 05/11] VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry NeilBrown
2024-12-20 2:54 ` [PATCH 06/11] VFS: introduce done_lookup_and_lock() NeilBrown
2024-12-20 2:54 ` [PATCH 07/11] VFS: introduce lookup_and_lock() NeilBrown
2024-12-20 2:54 ` [PATCH 08/11] VFS: add inode_dir_lock/unlock NeilBrown
2024-12-21 1:21 ` Hillf Danton
2024-12-23 3:10 ` NeilBrown
2024-12-23 11:12 ` Hillf Danton
2024-12-23 20:36 ` NeilBrown
2024-12-24 10:26 ` Hillf Danton
2024-12-20 2:54 ` [PATCH 09/11] VFS: re-pack DENTRY_ flags NeilBrown
2024-12-20 2:54 ` [PATCH 10/11] VFS: take a shared lock for create/remove directory operations NeilBrown
2024-12-23 5:19 ` Al Viro
2024-12-23 7:11 ` NeilBrown
2024-12-23 7:26 ` Al Viro
2024-12-23 20:40 ` NeilBrown
2024-12-20 2:54 ` [PATCH 11/11] nfsd: use lookup_and_lock_one() NeilBrown
2024-12-20 20:55 ` [PATCH 00/11 RFC] Allow concurrent changes in a directory Andreas Dilger
2024-12-23 5:22 ` Al Viro
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