From: Ian Kent Date: Thu, 24 Jul 2008 04:30:25 +0000 (-0700) Subject: autofs4: fix pending checks X-Git-Tag: v2.6.27-rc1~627 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26e81b3142f1ba497d4cd0365c13661684b784ce;p=linux-2.6 autofs4: fix pending checks There are two cases for which a dentry that has a pending mount request does not wait for completion. One is via autofs4_revalidate() and the other via autofs4_follow_link(). In revalidate, after the mount point directory is created, but before the mount is done, the check in try_to_fill_dentry() can can fail to send the dentry to the wait queue since the dentry is positive and the lookup flags may contain only LOOKUP_FOLLOW. Although we don't trigger a mount for the LOOKUP_FOLLOW flag, if ther's one pending we might as well wait and use the mounted dentry for the lookup. In autofs4_follow_link() the dentry is not checked to see if it is pending so it may fail to call try_to_fill_dentry() and not wait for mount completion. A dentry that is pending must always be sent to the wait queue. Signed-off-by: Ian Kent Reviewed-by: Jeff Moyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 51c873ca8e..61d1dca168 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -177,7 +177,8 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) return status; } /* Trigger mount for path component or follow link */ - } else if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) || + } else if (dentry->d_flags & DCACHE_AUTOFS_PENDING || + flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) || current->link_count) { DPRINTK("waiting for mount name=%.*s", dentry->d_name.len, dentry->d_name.name); @@ -223,7 +224,8 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) /* If it's our master or we shouldn't trigger a mount we're done */ lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS); - if (oz_mode || !lookup_type) + if (oz_mode || + !(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING)) goto done; /* If an expire request is pending wait for it. */ @@ -242,7 +244,8 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) * don't try to mount it again. */ spin_lock(&dcache_lock); - if (!d_mountpoint(dentry) && __simple_empty(dentry)) { + if (dentry->d_flags & DCACHE_AUTOFS_PENDING || + (!d_mountpoint(dentry) && __simple_empty(dentry))) { spin_unlock(&dcache_lock); status = try_to_fill_dentry(dentry, 0);