From fa736a951e456b996a76826ba78ff974414c3b55 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:44 -0500 Subject: sysfs, kernfs: move mount core code to fs/kernfs/mount.c 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 Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/kernfs-internal.h | 22 +++++++ fs/kernfs/mount.c | 156 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 178 insertions(+) (limited to 'fs/kernfs') diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 0d949885389d..ced0d6dadc7d 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -133,6 +133,28 @@ 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 */ diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 872e262e5166..84c83e24bf25 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -7,3 +7,159 @@ * * This file is released under the GPLv2. */ + +#include +#include +#include +#include +#include +#include + +#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(); +} -- cgit v1.2.3-58-ga151