[PATCH 38/41] sysfs, kernfs: move mount core code to fs/kernfs/mount.c

Tejun Heo
2013-11-23T22:23:26Z

Move core mount code to fs/kernfs/mount.c. The respective
declarations in fs/sysfs/sysfs.h are moved to
fs/kernfs/kernfs-internal.h.

This is pure relocation.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/kernfs/kernfs-internal.h | 22 +++++++
fs/kernfs/mount.c | 156 ++++++++++++++++++++++++++++++++++++++++++++
fs/sysfs/mount.c | 152 ------------------------------------------
fs/sysfs/sysfs.h | 18 -----
4 files changed, 178 insertions(+), 170 deletions(-)

diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 0d94988..ced0d6d 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -134,6 +134,28 @@ struct sysfs_addrm_cxt {
#include "../sysfs/sysfs.h"

/*
+ * mount.c
+ */
+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
+ * sysfs_dirent tag against every entry.
+ */
+ const void *ns;
+};
+#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
+
+extern struct kmem_cache *sysfs_dir_cachep;
+
+/*
* inode.c
*/
struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 872e262..84c83e2 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -7,3 +7,159 @@
*
* This file is released under the GPLv2.
*/
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/init.h>
+#include <linux/magic.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+
+#include "kernfs-internal.h"
+
+struct kmem_cache *sysfs_dir_cachep;
+
+static const struct super_operations sysfs_ops = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+ .evict_inode = sysfs_evict_inode,
+};
+
+static int sysfs_fill_super(struct super_block *sb)
+{
+ struct sysfs_super_info *info = sysfs_info(sb);
+ struct inode *inode;
+ struct dentry *root;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = SYSFS_MAGIC;
+ sb->s_op = &sysfs_ops;
+ sb->s_time_gran = 1;
+
+ /* get root inode, initialize and unlock it */
+ mutex_lock(&sysfs_mutex);
+ inode = sysfs_get_inode(sb, info->root->sd);
+ mutex_unlock(&sysfs_mutex);
+ if (!inode) {
+ pr_debug("sysfs: could not get root inode\n");
+ return -ENOMEM;
+ }
+
+ /* instantiate and link root dentry */
+ root = d_make_root(inode);
+ if (!root) {
+ pr_debug("%s: could not get root dentry!\n", __func__);
+ return -ENOMEM;
+ }
+ kernfs_get(info->root->sd);
+ root->d_fsdata = info->root->sd;
+ sb->s_root = root;
+ sb->s_d_op = &sysfs_dentry_ops;
+ return 0;
+}
+
+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->root == info->root && sb_info->ns == info->ns;
+}
+
+static int sysfs_set_super(struct super_block *sb, void *data)
+{
+ int error;
+ error = set_anon_super(sb, data);
+ if (!error)
+ sb->s_fs_info = data;
+ return error;
+}
+
+/**
+ * kernfs_super_ns - determine the namespace tag of a kernfs super_block
+ * @sb: super_block of interest
+ *
+ * Return the namespace tag associated with kernfs super_block @sb.
+ */
+const void *kernfs_super_ns(struct super_block *sb)
+{
+ struct sysfs_super_info *info = sysfs_info(sb);
+
+ return info->ns;
+}
+
+/**
+ * kernfs_mount_ns - kernfs mount helper
+ * @fs_type: file_system_type of the fs being mounted
+ * @flags: mount flags specified for the mount
+ * @root: kernfs_root of the hierarchy being mounted
+ * @ns: optional namespace tag of the mount
+ *
+ * This is to be called from each kernfs user's file_system_type->mount()
+ * implementation, which should pass through the specified @fs_type and
+ * @flags, and specify the hierarchy and namespace tag to mount via @root
+ * and @ns, respectively.
+ *
+ * The return value can be passed to the vfs layer verbatim.
+ */
+struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
+ struct kernfs_root *root, const void *ns)
+{
+ struct super_block *sb;
+ struct sysfs_super_info *info;
+ int error;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ info->root = root;
+ info->ns = ns;
+
+ sb = sget(fs_type, sysfs_test_super, sysfs_set_super, flags, info);
+ if (IS_ERR(sb) || sb->s_fs_info != info)
+ kfree(info);
+ if (IS_ERR(sb))
+ return ERR_CAST(sb);
+ if (!sb->s_root) {
+ error = sysfs_fill_super(sb);
+ if (error) {
+ deactivate_locked_super(sb);
+ return ERR_PTR(error);
+ }
+ sb->s_flags |= MS_ACTIVE;
+ }
+
+ return dget(sb->s_root);
+}
+
+/**
+ * kernfs_kill_sb - kill_sb for kernfs
+ * @sb: super_block being killed
+ *
+ * This can be used directly for file_system_type->kill_sb(). If a kernfs
+ * user needs extra cleanup, it can implement its own kill_sb() and call
+ * this function at the end.
+ */
+void kernfs_kill_sb(struct super_block *sb)
+{
+ struct sysfs_super_info *info = sysfs_info(sb);
+ struct sysfs_dirent *root_sd = sb->s_root->d_fsdata;
+
+ /*
+ * Remove the superblock from fs_supers/s_instances
+ * so we can't find it, before freeing sysfs_super_info.
+ */
+ kill_anon_super(sb);
+ kfree(info);
+ kernfs_put(root_sd);
+}
+
+void __init kernfs_init(void)
+{
+ sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
+ sizeof(struct sysfs_dirent),
+ 0, SLAB_PANIC, NULL);
+ sysfs_inode_init();
+}
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 5384732..e7e3aa8 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -14,91 +14,14 @@

#include <linux/fs.h>
#include <linux/mount.h>
-#include <linux/pagemap.h>
#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/magic.h>
-#include <linux/slab.h>
#include <linux/user_namespace.h>

#include "sysfs.h"

-
-struct kmem_cache *sysfs_dir_cachep;
-
-static const struct super_operations sysfs_ops = {
- .statfs = simple_statfs,
- .drop_inode = generic_delete_inode,
- .evict_inode = sysfs_evict_inode,
-};
-
static struct kernfs_root *sysfs_root;
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;
-
- sb->s_blocksize = PAGE_CACHE_SIZE;
- sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
- sb->s_magic = SYSFS_MAGIC;
- sb->s_op = &sysfs_ops;
- sb->s_time_gran = 1;
-
- /* get root inode, initialize and unlock it */
- mutex_lock(&sysfs_mutex);
- inode = sysfs_get_inode(sb, info->root->sd);
- mutex_unlock(&sysfs_mutex);
- if (!inode) {
- pr_debug("sysfs: could not get root inode\n");
- return -ENOMEM;
- }
-
- /* instantiate and link root dentry */
- root = d_make_root(inode);
- if (!root) {
- pr_debug("%s: could not get root dentry!\n", __func__);
- return -ENOMEM;
- }
- kernfs_get(info->root->sd);
- root->d_fsdata = info->root->sd;
- sb->s_root = root;
- sb->s_d_op = &sysfs_dentry_ops;
- return 0;
-}
-
-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->root == info->root && sb_info->ns == info->ns;
-}
-
-static int sysfs_set_super(struct super_block *sb, void *data)
-{
- int error;
- error = set_anon_super(sb, data);
- if (!error)
- sb->s_fs_info = data;
- return error;
-}
-
-/**
- * kernfs_super_ns - determine the namespace tag of a kernfs super_block
- * @sb: super_block of interest
- *
- * Return the namespace tag associated with kernfs super_block @sb.
- */
-const void *kernfs_super_ns(struct super_block *sb)
-{
- struct sysfs_super_info *info = sysfs_info(sb);
-
- return info->ns;
-}
-
static struct dentry *sysfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
@@ -120,79 +43,12 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
return root;
}

-/**
- * kernfs_mount_ns - kernfs mount helper
- * @fs_type: file_system_type of the fs being mounted
- * @flags: mount flags specified for the mount
- * @root: kernfs_root of the hierarchy being mounted
- * @ns: optional namespace tag of the mount
- *
- * This is to be called from each kernfs user's file_system_type->mount()
- * implementation, which should pass through the specified @fs_type and
- * @flags, and specify the hierarchy and namespace tag to mount via @root
- * and @ns, respectively.
- *
- * The return value can be passed to the vfs layer verbatim.
- */
-struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, const void *ns)
-{
- struct super_block *sb;
- struct sysfs_super_info *info;
- int error;
-
- info = kzalloc(sizeof(*info), GFP_KERNEL);
- if (!info)
- return ERR_PTR(-ENOMEM);
-
- info->root = root;
- info->ns = ns;
-
- sb = sget(fs_type, sysfs_test_super, sysfs_set_super, flags, info);
- if (IS_ERR(sb) || sb->s_fs_info != info)
- kfree(info);
- if (IS_ERR(sb))
- return ERR_CAST(sb);
- if (!sb->s_root) {
- error = sysfs_fill_super(sb);
- if (error) {
- deactivate_locked_super(sb);
- return ERR_PTR(error);
- }
- sb->s_flags |= MS_ACTIVE;
- }
-
- return dget(sb->s_root);
-}
-
static void sysfs_kill_sb(struct super_block *sb)
{
kernfs_kill_sb(sb);
kobj_ns_drop(KOBJ_NS_TYPE_NET, (void *)kernfs_super_ns(sb));
}

-/**
- * kernfs_kill_sb - kill_sb for kernfs
- * @sb: super_block being killed
- *
- * This can be used directly for file_system_type->kill_sb(). If a kernfs
- * user needs extra cleanup, it can implement its own kill_sb() and call
- * this function at the end.
- */
-void kernfs_kill_sb(struct super_block *sb)
-{
- struct sysfs_super_info *info = sysfs_info(sb);
- struct sysfs_dirent *root_sd = sb->s_root->d_fsdata;
-
- /*
- * Remove the superblock from fs_supers/s_instances
- * so we can't find it, before freeing sysfs_super_info.
- */
- kill_anon_super(sb);
- kfree(info);
- kernfs_put(root_sd);
-}
-
static struct file_system_type sysfs_fs_type = {
.name = "sysfs",
.mount = sysfs_mount,
@@ -200,14 +56,6 @@ static struct file_system_type sysfs_fs_type = {
.fs_flags = FS_USERNS_MOUNT,
};

-void __init kernfs_init(void)
-{
- sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
- sizeof(struct sysfs_dirent),
- 0, SLAB_PANIC, NULL);
- sysfs_inode_init();
-}
-
int __init sysfs_init(void)
{
int err;
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 93b4b68..6a82311 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -17,25 +17,7 @@
/*
* mount.c
*/
-
-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
- * sysfs_dirent tag against every entry.
- */
- const void *ns;
-};
-#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
extern struct sysfs_dirent *sysfs_root_sd;
-extern struct kmem_cache *sysfs_dir_cachep;

/*
* dir.c
--
1.8.4.2