From: David Vrabel <david.vrabel@citrix.com>
To: xen-devel@lists.xenproject.org
Cc: Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
David Vrabel <david.vrabel@citrix.com>
Subject: [PATCHv1 2/2] xen/xenfs: replace xenbus and privcmd with symlinks
Date: Mon, 16 May 2016 18:44:06 +0100 [thread overview]
Message-ID: <1463420646-29530-3-git-send-email-david.vrabel@citrix.com> (raw)
In-Reply-To: <1463420646-29530-1-git-send-email-david.vrabel@citrix.com>
/proc/xen/xenbus does not work correctly. A read blocked waiting for
a xenbus message will deadlock a write to the same file handle due to
the requirement for atomic file position updates on regular files.
/proc/xen/xenbus and /proc/xen/privcmd are supposed to be identical to
the character devices /dev/xen/xenbus and /dev/xen/privcmd so replace
the files with symlinks.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
drivers/xen/xenfs/super.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 8559a71..09c239e 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -45,16 +45,16 @@ static const struct file_operations capabilities_file_ops = {
static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
{
static struct tree_descr xenfs_files[] = {
- [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
+ [2] = { "xenbus", NULL, S_IFLNK | S_IRWXUGO, "/dev/xen/xenbus" },
{ "capabilities", &capabilities_file_ops, S_IRUGO },
- { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
+ { "privcmd", NULL, S_IFLNK | S_IRWXUGO, "/dev/xen/privcmd" },
{""},
};
static struct tree_descr xenfs_init_files[] = {
- [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
+ [2] = { "xenbus", NULL, S_IFLNK | S_IRWXUGO, "/dev/xen/xenbus" },
{ "capabilities", &capabilities_file_ops, S_IRUGO },
- { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
+ { "privcmd", NULL, S_IFLNK | S_IRWXUGO, "/dev/xen/privcmd" },
{ "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
{ "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
#ifdef CONFIG_XEN_SYMS
--
2.1.4
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next prev parent reply other threads:[~2016-05-16 17:44 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-16 17:44 [PATCHv1 0/2] xen/xenfs: fix /proc/xen/xenbus David Vrabel
2016-05-16 17:44 ` [PATCHv1 1/2] libfs: allow simple_fill_super() to add symlinks David Vrabel
2016-05-16 17:44 ` David Vrabel [this message]
2016-05-16 18:36 ` [PATCHv1 0/2] xen/xenfs: fix /proc/xen/xenbus Boris Ostrovsky
2016-05-16 22:23 ` Doug Goldstein
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