diff mbox

[4/4] dcache: don't clear DCACHE_DISCONNECTED too early

Message ID 1378579561-26868-5-git-send-email-bfields@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Bruce Fields Sept. 7, 2013, 6:46 p.m. UTC 
From: "J. Bruce Fields" <bfields@redhat.com>

DCACHE_DISCONNECTED should not be cleared until we're sure the dentry is
connected all the way up to the root of the filesystem.  It *shouldn't*
be cleared as soon as the dentry is connected to a parent.  That will
cause bugs at least on exportable filesystems.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/dcache.c |    1 -
 1 file changed, 1 deletion(-)

Comments

Al Viro Sept. 9, 2013, 12:46 a.m. UTC | #1 
On Sat, Sep 07, 2013 at 02:46:01PM -0400, J. Bruce Fields wrote:
> From: "J. Bruce Fields" <bfields@redhat.com>
> 
> DCACHE_DISCONNECTED should not be cleared until we're sure the dentry is
> connected all the way up to the root of the filesystem.  It *shouldn't*
> be cleared as soon as the dentry is connected to a parent.  That will
> cause bugs at least on exportable filesystems.

Then you probably want this
                if (!IS_ROOT(pd)) {
                        /* must have found a connected parent - great */
                        spin_lock(&pd->d_lock);
                        pd->d_flags &= ~DCACHE_DISCONNECTED;
                        spin_unlock(&pd->d_lock);
                        noprogress = 0;
to go through all intermediates, clearing DCACHE_DISCONNECTED on all of
them; O(depth^2) can suck when we have a long chain of directories...
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Christoph Hellwig Sept. 9, 2013, 7:45 a.m. UTC | #2 
On Mon, Sep 09, 2013 at 01:46:47AM +0100, Al Viro wrote:
> On Sat, Sep 07, 2013 at 02:46:01PM -0400, J. Bruce Fields wrote:
> > From: "J. Bruce Fields" <bfields@redhat.com>
> > 
> > DCACHE_DISCONNECTED should not be cleared until we're sure the dentry is
> > connected all the way up to the root of the filesystem.  It *shouldn't*
> > be cleared as soon as the dentry is connected to a parent.  That will
> > cause bugs at least on exportable filesystems.
> 
> Then you probably want this
>                 if (!IS_ROOT(pd)) {
>                         /* must have found a connected parent - great */
>                         spin_lock(&pd->d_lock);
>                         pd->d_flags &= ~DCACHE_DISCONNECTED;
>                         spin_unlock(&pd->d_lock);
>                         noprogress = 0;
> to go through all intermediates, clearing DCACHE_DISCONNECTED on all of
> them; O(depth^2) can suck when we have a long chain of directories...

Aka call reconnect_path() from fs/exportfs/expfs.c on it.

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diff mbox

Patch

diff --git a/fs/dcache.c b/fs/dcache.c
index a53f55d..a4560ca 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2404,7 +2404,6 @@  static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
 	spin_unlock(&dentry->d_lock);
 
 	/* anon->d_lock still locked, returns locked */
-	anon->d_flags &= ~DCACHE_DISCONNECTED;
 }
 
 /**