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authorTejun Heo <tj@kernel.org>2013-11-28 19:54:42 (GMT)
committerPawel Osmialowski <p.osmialowsk@mcdsrvbld02.digital.local>2015-03-27 17:13:18 (GMT)
commit0018694815f92477b40edbad679752974e140b87 (patch)
tree3f27a06e70b9d9c7dc0491fe1f7e23117a908962
parent2856420896f24ced79bde2697f61c6d5faec6ac2 (diff)
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sysfs, kernfs: make super_blocks bind to different kernfs_roots
kernfs is being updated to allow multiple sysfs_dirent hierarchies so that it can also be used by other users. Currently, sysfs super_blocks are always attached to one kernfs_root - sysfs_root - and distinguished only by their namespace tags. This patch adds sysfs_super_info->root and update sysfs_fill/test_super() so that super_blocks are identified by the combination of both the associated kernfs_root and namespace tag. This allows mounting different kernfs hierarchies. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/sysfs/mount.c10
-rw-r--r--fs/sysfs/sysfs.h6
2 files changed, 12 insertions, 4 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 0b5661b..f143b20 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -37,6 +37,7 @@ struct sysfs_dirent *sysfs_root_sd;
static int sysfs_fill_super(struct super_block *sb)
{
+ struct sysfs_super_info *info = sysfs_info(sb);
struct inode *inode;
struct dentry *root;
@@ -48,7 +49,7 @@ static int sysfs_fill_super(struct super_block *sb)
/* get root inode, initialize and unlock it */
mutex_lock(&sysfs_mutex);
- inode = sysfs_get_inode(sb, sysfs_root_sd);
+ inode = sysfs_get_inode(sb, info->root->sd);
mutex_unlock(&sysfs_mutex);
if (!inode) {
pr_debug("sysfs: could not get root inode\n");
@@ -61,8 +62,8 @@ static int sysfs_fill_super(struct super_block *sb)
pr_debug("%s: could not get root dentry!\n", __func__);
return -ENOMEM;
}
- kernfs_get(sysfs_root_sd);
- root->d_fsdata = sysfs_root_sd;
+ kernfs_get(info->root->sd);
+ root->d_fsdata = info->root->sd;
sb->s_root = root;
sb->s_d_op = &sysfs_dentry_ops;
return 0;
@@ -73,7 +74,7 @@ static int sysfs_test_super(struct super_block *sb, void *data)
struct sysfs_super_info *sb_info = sysfs_info(sb);
struct sysfs_super_info *info = data;
- return sb_info->ns == info->ns;
+ return sb_info->root == info->root && sb_info->ns == info->ns;
}
static int sysfs_set_super(struct super_block *sb, void *data)
@@ -110,6 +111,7 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
if (!info)
return ERR_PTR(-ENOMEM);
+ info->root = sysfs_root;
info->ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
sb = sget(fs_type, sysfs_test_super, sysfs_set_super, flags, info);
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 2b217ce..93b4b68 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -20,6 +20,12 @@
struct sysfs_super_info {
/*
+ * The root associated with this super_block. Each super_block is
+ * identified by the root and ns it's associated with.
+ */
+ struct kernfs_root *root;
+
+ /*
* Each sb is associated with one namespace tag, currently the network
* namespace of the task which mounted this sysfs instance. If multiple
* tags become necessary, make the following an array and compare