On Thu, 2007-08-23 at 12:36 -0500, Florin Iucha wrote: > On Thu, Aug 23, 2007 at 10:14:38AM -0700, Bret Towe wrote: > > this sounds alot like the post i did yesterday titled 'nfs4 hang regression' > > i tracked it down to commit 3d39c691ff486142dd9aaeac12f553f4476b7a6 > > Yes, it certainly does -- all the symptoms match! > > I'm not [alone in] seeing dead keyboards! > > Now, if only somebody could clarify to me the connection between > the bad NFS4 shooting the keyboard but not the mouse, that would > be wonderful. > > florin
Could you and Bret please check if the attached patch fixes the hang? Cheers Trond
--- Begin Message ---We need to ensure that nobody adds anything to nfs_automount_list while we are killing off the work queue entry, or else nfs_expire_automounts will simply rearm it, and we hang. Signed-off-by: Trond Myklebust <[EMAIL PROTECTED]> --- fs/nfs/namespace.c | 14 +++++++++++++- 1 files changed, 13 insertions(+), 1 deletions(-) diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index aea76d0..bcd0777 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -22,6 +22,11 @@ static void nfs_expire_automounts(struct work_struct *work); LIST_HEAD(nfs_automount_list); static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts); +/* + * The following mutex prevents nfs_follow_mountpoint from adding new + * entries to nfs_automount_list + */ +static DEFINE_MUTEX(nfs_automount_mutex); int nfs_mountpoint_expiry_timeout = 500 * HZ; static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent, @@ -128,18 +133,21 @@ static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd) goto out_err; mntget(mnt); + mutex_lock(&nfs_automount_mutex); err = do_add_mount(mnt, nd, nd->mnt->mnt_flags|MNT_SHRINKABLE, &nfs_automount_list); if (err < 0) { + mutex_unlock(&nfs_automount_mutex); mntput(mnt); if (err == -EBUSY) goto out_follow; goto out_err; } + schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout); + mutex_unlock(&nfs_automount_mutex); mntput(nd->mnt); dput(nd->dentry); nd->mnt = mnt; nd->dentry = dget(mnt->mnt_root); - schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout); out: dprintk("%s: done, returned %d\n", __FUNCTION__, err); @@ -175,8 +183,12 @@ static void nfs_expire_automounts(struct work_struct *work) void nfs_release_automount_timer(void) { + if (!list_empty(&nfs_automount_list)) + return; + mutex_lock(&nfs_automount_mutex); if (list_empty(&nfs_automount_list)) cancel_delayed_work_sync(&nfs_automount_task); + mutex_unlock(&nfs_automount_mutex); } /*
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