From: Al Viro <viro@ZenIV.linux.org.uk>
To: NeilBrown <neilb@suse.de>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 10/13] VFS/namei: handle LOOKUP_RCU in page_follow_link_light.
Date: Mon, 16 Mar 2015 22:50:40 +0000 [thread overview]
Message-ID: <20150316225040.GG29656@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20150316044320.23648.90827.stgit@notabene.brown>
On Mon, Mar 16, 2015 at 03:43:20PM +1100, NeilBrown wrote:
> + char *kaddr;
> + struct page *page;
> + struct address_space *mapping = dentry->d_inode->i_mapping;
Who said that dentry->d_inode hasn't gone NULL by that point?
> + nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
... or changed here. Again, dentry->d_inode is stable only if you are
holding a reference to dentry. That's why we have those dances around
nd->inode, for example. Doing unlazy_walk() is enough to stabilize the
damn thing, so currently ->follow_link() doesn't have to worry about it.
With your changes, though...
next prev parent reply other threads:[~2015-03-16 22:50 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-16 4:43 [PATCH 00/13] Support follow_link in RCU-walk. - V2 NeilBrown
2015-03-16 4:43 ` [PATCH 03/13] VFS: remove nameidata args from ->follow_link and ->put_link NeilBrown
2015-03-16 20:47 ` Al Viro
2015-03-16 4:43 ` [PATCH 04/13] security/selinux: check for LOOKUP_RCU in _follow_link NeilBrown
2015-03-16 21:00 ` Al Viro
2015-03-20 4:39 ` NeilBrown
2015-03-20 5:12 ` Al Viro
2015-03-16 4:43 ` [PATCH 01/13] VFS: replace {, total_}link_count in task_struct with pointer to nameidata NeilBrown
2015-03-16 19:46 ` Al Viro
2015-03-16 4:43 ` [PATCH 02/13] VFS: make all ->follow_link handlers aware for LOOKUP_RCU NeilBrown
2015-03-16 4:43 ` [PATCH 11/13] xfs: use RCU to free 'struct xfs_mount' NeilBrown
2015-03-16 4:43 ` [PATCH 07/13] VFS/namei: abort RCU-walk on symlink if atime needs updating NeilBrown
2015-03-16 4:43 ` [PATCH 10/13] VFS/namei: handle LOOKUP_RCU in page_follow_link_light NeilBrown
2015-03-16 22:50 ` Al Viro [this message]
2015-03-19 22:38 ` NeilBrown
2015-03-19 23:46 ` Al Viro
2015-03-16 4:43 ` [PATCH 05/13] VFS/namei: use terminate_walk when symlink lookup fails NeilBrown
2015-03-16 4:43 ` [PATCH 09/13] VFS/namei: enable RCU-walk when following symlinks NeilBrown
2015-03-16 22:44 ` Al Viro
2015-03-16 4:43 ` [PATCH 13/13] NFS: support LOOKUP_RCU in nfs_follow_link NeilBrown
2015-03-16 4:43 ` [PATCH 08/13] VFS/namei: enhance follow_link to support RCU-walk NeilBrown
2015-03-16 4:43 ` [PATCH 06/13] VFS/namei: new flag to support RCU symlinks: LOOKUP_LINK_RCU NeilBrown
2015-03-16 22:33 ` Al Viro
2015-03-17 0:59 ` Al Viro
2015-03-16 4:43 ` [PATCH 12/13] XFS: allow follow_link to often succeed in RCU-walk NeilBrown
2015-03-16 22:37 ` Al Viro
2015-03-16 19:14 ` [PATCH 00/13] Support follow_link in RCU-walk. - V2 Al Viro
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