From 137fdcc18a5979b53c0a1379b25fc68724e98a45 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Wed, 11 Sep 2013 14:26:06 -0700 Subject: initmpfs: replace MS_NOUSER in initramfs Mounting MS_NOUSER prevents --bind mounts from rootfs. Prevent new rootfs mounts with a different mechanism that doesn't affect bind mounts. Signed-off-by: Rob Landley Cc: Jeff Layton Cc: Jens Axboe Cc: Stephen Warren Cc: Rusty Russell Cc: Jim Cromie Cc: Sam Ravnborg Cc: Greg Kroah-Hartman Cc: "Eric W. Biederman" Cc: Alexander Viro Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ramfs/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/ramfs/inode.c') diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c index c24f1e10b946..8f7fe323e049 100644 --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -247,7 +247,12 @@ struct dentry *ramfs_mount(struct file_system_type *fs_type, static struct dentry *rootfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - return mount_nodev(fs_type, flags|MS_NOUSER, data, ramfs_fill_super); + static unsigned long once; + + if (test_and_set_bit(1, &once)) + return ERR_PTR(-ENODEV); + + return mount_nodev(fs_type, flags, data, ramfs_fill_super); } static void ramfs_kill_sb(struct super_block *sb) -- cgit v1.2.3 From 4bbee76bc986af326be0a84ad661000cf89b29f6 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Wed, 11 Sep 2013 14:26:08 -0700 Subject: initmpfs: move bdi setup from init_rootfs to init_ramfs Even though ramfs hasn't got a backing device, commit e0bf68ddec4f ("mm: bdi init hooks") added one anyway, and put the initialization in init_rootfs() since that's the first user, leaving it out of init_ramfs() to avoid duplication. But initmpfs uses init_tmpfs() instead, so move the init into the filesystem's init function, add a "once" guard to prevent duplicate initialization, and call the filesystem init from rootfs init. This goes part of the way to allowing ramfs to be built as a module. [akpm@linux-foundation.org; using bit 1 was odd] Signed-off-by: Rob Landley Cc: Jeff Layton Cc: Jens Axboe Cc: Stephen Warren Cc: Rusty Russell Cc: Jim Cromie Cc: Sam Ravnborg Cc: Greg Kroah-Hartman Cc: "Eric W. Biederman" Cc: Alexander Viro Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ramfs/inode.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) (limited to 'fs/ramfs/inode.c') diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c index 8f7fe323e049..fb99863598be 100644 --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -249,7 +249,7 @@ static struct dentry *rootfs_mount(struct file_system_type *fs_type, { static unsigned long once; - if (test_and_set_bit(1, &once)) + if (test_and_set_bit(0, &once)) return ERR_PTR(-ENODEV); return mount_nodev(fs_type, flags, data, ramfs_fill_super); @@ -275,21 +275,34 @@ static struct file_system_type rootfs_fs_type = { static int __init init_ramfs_fs(void) { - return register_filesystem(&ramfs_fs_type); + static unsigned long once; + int err; + + if (test_and_set_bit(0, &once)) + return 0; + + err = bdi_init(&ramfs_backing_dev_info); + if (err) + return err; + + err = register_filesystem(&ramfs_fs_type); + if (err) + bdi_destroy(&ramfs_backing_dev_info); + + return err; } module_init(init_ramfs_fs) int __init init_rootfs(void) { - int err; + int err = register_filesystem(&rootfs_fs_type); - err = bdi_init(&ramfs_backing_dev_info); if (err) return err; - err = register_filesystem(&rootfs_fs_type); + err = init_ramfs_fs(); if (err) - bdi_destroy(&ramfs_backing_dev_info); + unregister_filesystem(&rootfs_fs_type); return err; } -- cgit v1.2.3 From 57f150a58c40cda598c31af8bceb8598f43c3e5f Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Wed, 11 Sep 2013 14:26:10 -0700 Subject: initmpfs: move rootfs code from fs/ramfs/ to init/ When the rootfs code was a wrapper around ramfs, having them in the same file made sense. Now that it can wrap another filesystem type, move it in with the init code instead. This also allows a subsequent patch to access rootfstype= command line arg. Signed-off-by: Rob Landley Cc: Jeff Layton Cc: Jens Axboe Cc: Stephen Warren Cc: Rusty Russell Cc: Jim Cromie Cc: Sam Ravnborg Cc: Greg Kroah-Hartman Cc: "Eric W. Biederman" Cc: Alexander Viro Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ramfs/inode.c | 32 +------------------------------- 1 file changed, 1 insertion(+), 31 deletions(-) (limited to 'fs/ramfs/inode.c') diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c index fb99863598be..39d14659a8d3 100644 --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -244,17 +244,6 @@ struct dentry *ramfs_mount(struct file_system_type *fs_type, return mount_nodev(fs_type, flags, data, ramfs_fill_super); } -static struct dentry *rootfs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) -{ - static unsigned long once; - - if (test_and_set_bit(0, &once)) - return ERR_PTR(-ENODEV); - - return mount_nodev(fs_type, flags, data, ramfs_fill_super); -} - static void ramfs_kill_sb(struct super_block *sb) { kfree(sb->s_fs_info); @@ -267,13 +256,8 @@ static struct file_system_type ramfs_fs_type = { .kill_sb = ramfs_kill_sb, .fs_flags = FS_USERNS_MOUNT, }; -static struct file_system_type rootfs_fs_type = { - .name = "rootfs", - .mount = rootfs_mount, - .kill_sb = kill_litter_super, -}; -static int __init init_ramfs_fs(void) +int __init init_ramfs_fs(void) { static unsigned long once; int err; @@ -292,17 +276,3 @@ static int __init init_ramfs_fs(void) return err; } module_init(init_ramfs_fs) - -int __init init_rootfs(void) -{ - int err = register_filesystem(&rootfs_fs_type); - - if (err) - return err; - - err = init_ramfs_fs(); - if (err) - unregister_filesystem(&rootfs_fs_type); - - return err; -} -- cgit v1.2.3