From: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Cc: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org,
Dave Hansen
<dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Subject: [RFC][PATCH 3/5] fs: add get_sb_single_ns() helper routine
Date: Thu, 10 Jul 2008 15:30:50 -0700 [thread overview]
Message-ID: <20080710223050.75DB117C@kernel> (raw)
In-Reply-To: <20080710223047.315FF88A@kernel>
From: Cedric Le Goater <clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
This patch add a helper routine get_sb_single_ns() which allocates
a single super_block per instance of namespace. The data parameter
is used to differentiate the namespaces.
This is used in subsystems with an internal fs like mqueue.
TODO:
- use in pidns and devpts
Signed-off-by: Cedric Le Goater <clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
---
linux-2.6.git-dave/fs/super.c | 37 ++++++++++++++++++++++++++++++++++
linux-2.6.git-dave/include/linux/fs.h | 4 +++
2 files changed, 41 insertions(+)
diff -puN fs/super.c~add-get_sb_single_ns-helper fs/super.c
--- linux-2.6.git/fs/super.c~add-get_sb_single_ns-helper 2008-06-24 12:03:17.000000000 -0700
+++ linux-2.6.git-dave/fs/super.c 2008-06-24 12:03:17.000000000 -0700
@@ -882,6 +882,43 @@ int get_sb_single(struct file_system_typ
EXPORT_SYMBOL(get_sb_single);
+static int compare_sb_single_ns(struct super_block *sb, void *data)
+{
+ return sb->s_fs_info == data;
+}
+
+static int set_sb_single_ns(struct super_block *sb, void *data)
+{
+ sb->s_fs_info = data;
+ return set_anon_super(sb, data);
+}
+
+int get_sb_single_ns(struct file_system_type *fs_type,
+ int flags, void *data,
+ int (*fill_super)(struct super_block *, void *, int),
+ struct vfsmount *mnt)
+{
+ struct super_block *s;
+ int error;
+
+ s = sget(fs_type, compare_sb_single_ns, set_sb_single_ns, data);
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+ if (!s->s_root) {
+ s->s_flags = flags;
+ error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
+ if (error) {
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ return error;
+ }
+ s->s_flags |= MS_ACTIVE;
+ }
+ do_remount_sb(s, flags, data, 0);
+ return simple_set_mnt(mnt, s);
+}
+EXPORT_SYMBOL(get_sb_single_ns);
+
struct vfsmount *
vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
{
diff -puN include/linux/fs.h~add-get_sb_single_ns-helper include/linux/fs.h
--- linux-2.6.git/include/linux/fs.h~add-get_sb_single_ns-helper 2008-06-24 12:03:17.000000000 -0700
+++ linux-2.6.git-dave/include/linux/fs.h 2008-06-24 12:03:17.000000000 -0700
@@ -1502,6 +1502,10 @@ extern int get_sb_nodev(struct file_syst
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt);
+extern int get_sb_single_ns(struct file_system_type *fs_type,
+ int flags, void *data,
+ int (*fill_super)(struct super_block *, void *, int),
+ struct vfsmount *mnt);
void generic_shutdown_super(struct super_block *sb);
void kill_block_super(struct super_block *sb);
void kill_anon_super(struct super_block *sb);
_
next prev parent reply other threads:[~2008-07-10 22:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-10 22:30 [RFC][PATCH 1/5] mqueue namespace: add struct mq_namespace Dave Hansen
2008-07-10 22:30 ` [RFC][PATCH 2/5] mqueue namespace: add unshare support Dave Hansen
2008-07-10 22:58 ` Daniel Hokka Zakrisson
2008-07-10 22:30 ` Dave Hansen [this message]
2008-07-10 22:30 ` [RFC][PATCH 4/5] mqueue namespace: enable the mqueue namespace Dave Hansen
2008-07-10 22:30 ` [RFC][PATCH 5/5] Subject: mqueue namespace: adapt sysctl Dave Hansen
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