From 9e7fdd25b21ebf50713dfb7702af57c270e5572a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 30 Mar 2010 11:31:24 -0700 Subject: [PATCH] sysfs: Basic support for multiple super blocks Add all of the necessary bioler plate to support multiple superblocks in sysfs. Signed-off-by: Eric W. Biederman Acked-by: Serge Hallyn Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/mount.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++-- fs/sysfs/sysfs.h | 3 +++ 2 files changed, 59 insertions(+), 2 deletions(-) diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 776137828dca..db0b1f2138af 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -72,16 +72,70 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent) 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; + int found = 1; + return found; +} + +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; +} + static int sysfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { - return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt); + struct sysfs_super_info *info; + struct super_block *sb; + int error; + + error = -ENOMEM; + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + goto out; + sb = sget(fs_type, sysfs_test_super, sysfs_set_super, info); + if (IS_ERR(sb) || sb->s_fs_info != info) + kfree(info); + if (IS_ERR(sb)) { + kfree(info); + error = PTR_ERR(sb); + goto out; + } + if (!sb->s_root) { + sb->s_flags = flags; + error = sysfs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); + if (error) { + deactivate_locked_super(sb); + goto out; + } + sb->s_flags |= MS_ACTIVE; + } + + simple_set_mnt(mnt, sb); + error = 0; +out: + return error; +} + +static void sysfs_kill_sb(struct super_block *sb) +{ + struct sysfs_super_info *info = sysfs_info(sb); + + kill_anon_super(sb); + kfree(info); } static struct file_system_type sysfs_fs_type = { .name = "sysfs", .get_sb = sysfs_get_sb, - .kill_sb = kill_anon_super, + .kill_sb = sysfs_kill_sb, }; int __init sysfs_init(void) diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 30f5a44fb5d3..030a39dbb02c 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -114,6 +114,9 @@ struct sysfs_addrm_cxt { /* * mount.c */ +struct sysfs_super_info { +}; +#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info)) extern struct sysfs_dirent sysfs_root; extern struct kmem_cache *sysfs_dir_cachep; -- 2.20.1