Merge branch 'readonly-snapshots' of git://repo.or.cz/linux-btrfs-devel into btrfs-38 (26c79f6b) · Commits · e / devices / android_kernel_xiaomi_markw

fs/btrfs/ctree.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -597,6 +597,8 @@ struct btrfs_dir_item {
		u8 type;
		} __attribute__ ((__packed__));

		#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)

		struct btrfs_root_item {
		struct btrfs_inode_item inode;
		__le64 generation;
		@@ -1893,6 +1895,11 @@ BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);
		BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
		last_snapshot, 64);

		static inline bool btrfs_root_readonly(struct btrfs_root *root)
		{
		return root->root_item.flags & BTRFS_ROOT_SUBVOL_RDONLY;
		}

		/* struct btrfs_super_block */

		BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);

fs/btrfs/inode.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -3671,8 +3671,12 @@ static int btrfs_setattr_size(struct inode inode, struct iattr attr)
		static int btrfs_setattr(struct dentry dentry, struct iattr attr)
		{
		struct inode *inode = dentry->d_inode;
		struct btrfs_root *root = BTRFS_I(inode)->root;
		int err;

		if (btrfs_root_readonly(root))
		return -EROFS;

		err = inode_change_ok(inode, attr);
		if (err)
		return err;
		@@ -7206,6 +7210,10 @@ static int btrfs_set_page_dirty(struct page *page)

		static int btrfs_permission(struct inode *inode, int mask)
		{
		struct btrfs_root *root = BTRFS_I(inode)->root;

		if (btrfs_root_readonly(root) && (mask & MAY_WRITE))
		return -EROFS;
		if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
		return -EACCES;
		return generic_permission(inode, mask, btrfs_check_acl);

fs/btrfs/ioctl.c

+150 −49

Original line number	Diff line number	Diff line
		@@ -147,6 +147,9 @@ static int btrfs_ioctl_setflags(struct file file, void __user arg)
		unsigned int flags, oldflags;
		int ret;

		if (btrfs_root_readonly(root))
		return -EROFS;

		if (copy_from_user(&flags, arg, sizeof(flags)))
		return -EFAULT;

		@@ -360,7 +363,8 @@ fail:
		}

		static int create_snapshot(struct btrfs_root root, struct dentry dentry,
		char name, int namelen, u64 async_transid)
		char name, int namelen, u64 async_transid,
		bool readonly)
		{
		struct inode *inode;
		struct dentry *parent;
		@@ -378,6 +382,7 @@ static int create_snapshot(struct btrfs_root root, struct dentry dentry,
		btrfs_init_block_rsv(&pending_snapshot->block_rsv);
		pending_snapshot->dentry = dentry;
		pending_snapshot->root = root;
		pending_snapshot->readonly = readonly;

		trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
		if (IS_ERR(trans)) {
		@@ -509,7 +514,7 @@ static inline int btrfs_may_create(struct inode dir, struct dentry child)
		static noinline int btrfs_mksubvol(struct path *parent,
		char *name, int namelen,
		struct btrfs_root *snap_src,
		u64 *async_transid)
		u64 *async_transid, bool readonly)
		{
		struct inode *dir = parent->dentry->d_inode;
		struct dentry *dentry;
		@@ -541,7 +546,7 @@ static noinline int btrfs_mksubvol(struct path *parent,

		if (snap_src) {
		error = create_snapshot(snap_src, dentry,
		name, namelen, async_transid);
		name, namelen, async_transid, readonly);
		} else {
		error = create_subvol(BTRFS_I(dir)->root, dentry,
		name, namelen, async_transid);
		@@ -901,7 +906,8 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
		char *name,
		unsigned long fd,
		int subvol,
		u64 *transid)
		u64 *transid,
		bool readonly)
		{
		struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
		struct file *src_file;
		@@ -919,7 +925,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,

		if (subvol) {
		ret = btrfs_mksubvol(&file->f_path, name, namelen,
		NULL, transid);
		NULL, transid, readonly);
		} else {
		struct inode *src_inode;
		src_file = fget(fd);
		@@ -938,7 +944,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
		}
		ret = btrfs_mksubvol(&file->f_path, name, namelen,
		BTRFS_I(src_inode)->root,
		transid);
		transid, readonly);
		fput(src_file);
		}
		out:
		@@ -946,61 +952,142 @@ out:
		}

		static noinline int btrfs_ioctl_snap_create(struct file *file,
		void __user *arg, int subvol,
		int v2)
		void __user *arg, int subvol)
		{
		struct btrfs_ioctl_vol_args *vol_args = NULL;
		struct btrfs_ioctl_vol_args_v2 *vol_args_v2 = NULL;
		char *name;
		u64 fd;
		struct btrfs_ioctl_vol_args *vol_args;
		int ret;

		if (v2) {
		vol_args = memdup_user(arg, sizeof(*vol_args));
		if (IS_ERR(vol_args))
		return PTR_ERR(vol_args);
		vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

		ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
		vol_args->fd, subvol,
		NULL, false);

		kfree(vol_args);
		return ret;
		}

		static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
		void __user *arg, int subvol)
		{
		struct btrfs_ioctl_vol_args_v2 *vol_args;
		int ret;
		u64 transid = 0;
		u64 *ptr = NULL;
		bool readonly = false;

		vol_args_v2 = memdup_user(arg, sizeof(*vol_args_v2));
		if (IS_ERR(vol_args_v2))
		return PTR_ERR(vol_args_v2);
		vol_args = memdup_user(arg, sizeof(*vol_args));
		if (IS_ERR(vol_args))
		return PTR_ERR(vol_args);
		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';

		if (vol_args_v2->flags & ~BTRFS_SUBVOL_CREATE_ASYNC) {
		ret = -EINVAL;
		if (vol_args->flags &
		~(BTRFS_SUBVOL_CREATE_ASYNC \| BTRFS_SUBVOL_RDONLY)) {
		ret = -EOPNOTSUPP;
		goto out;
		}

		name = vol_args_v2->name;
		fd = vol_args_v2->fd;
		vol_args_v2->name[BTRFS_SUBVOL_NAME_MAX] = '\0';

		if (vol_args_v2->flags & BTRFS_SUBVOL_CREATE_ASYNC)
		if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
		ptr = &transid;
		if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
		readonly = true;

		ret = btrfs_ioctl_snap_create_transid(file, name, fd,
		subvol, ptr);
		ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
		vol_args->fd, subvol,
		ptr, readonly);

		if (ret == 0 && ptr &&
		copy_to_user(arg +
		offsetof(struct btrfs_ioctl_vol_args_v2,
		transid), ptr, sizeof(*ptr)))
		ret = -EFAULT;
		} else {
		vol_args = memdup_user(arg, sizeof(*vol_args));
		if (IS_ERR(vol_args))
		return PTR_ERR(vol_args);
		name = vol_args->name;
		fd = vol_args->fd;
		vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

		ret = btrfs_ioctl_snap_create_transid(file, name, fd,
		subvol, NULL);
		}
		out:
		kfree(vol_args);
		kfree(vol_args_v2);
		return ret;
		}

		static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
		void __user *arg)
		{
		struct inode *inode = fdentry(file)->d_inode;
		struct btrfs_root *root = BTRFS_I(inode)->root;
		int ret = 0;
		u64 flags = 0;

		if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
		return -EINVAL;

		down_read(&root->fs_info->subvol_sem);
		if (btrfs_root_readonly(root))
		flags \|= BTRFS_SUBVOL_RDONLY;
		up_read(&root->fs_info->subvol_sem);

		if (copy_to_user(arg, &flags, sizeof(flags)))
		ret = -EFAULT;

		return ret;
		}

		static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
		void __user *arg)
		{
		struct inode *inode = fdentry(file)->d_inode;
		struct btrfs_root *root = BTRFS_I(inode)->root;
		struct btrfs_trans_handle *trans;
		u64 root_flags;
		u64 flags;
		int ret = 0;

		if (root->fs_info->sb->s_flags & MS_RDONLY)
		return -EROFS;

		if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
		return -EINVAL;

		if (copy_from_user(&flags, arg, sizeof(flags)))
		return -EFAULT;

		if (flags & ~BTRFS_SUBVOL_CREATE_ASYNC)
		return -EINVAL;

		if (flags & ~BTRFS_SUBVOL_RDONLY)
		return -EOPNOTSUPP;

		down_write(&root->fs_info->subvol_sem);

		/* nothing to do */
		if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
		goto out;

		root_flags = btrfs_root_flags(&root->root_item);
		if (flags & BTRFS_SUBVOL_RDONLY)
		btrfs_set_root_flags(&root->root_item,
		root_flags \| BTRFS_ROOT_SUBVOL_RDONLY);
		else
		btrfs_set_root_flags(&root->root_item,
		root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);

		trans = btrfs_start_transaction(root, 1);
		if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out_reset;
		}

		ret = btrfs_update_root(trans, root,
		&root->root_key, &root->root_item);

		btrfs_commit_transaction(trans, root);
		out_reset:
		if (ret)
		btrfs_set_root_flags(&root->root_item, root_flags);
		out:
		up_write(&root->fs_info->subvol_sem);
		return ret;
		}

		/*
		* helper to check if the subvolume references other subvolumes
		*/
		@@ -1509,6 +1596,9 @@ static int btrfs_ioctl_defrag(struct file file, void __user argp)
		struct btrfs_ioctl_defrag_range_args *range;
		int ret;

		if (btrfs_root_readonly(root))
		return -EROFS;

		ret = mnt_want_write(file->f_path.mnt);
		if (ret)
		return ret;
		@@ -1637,6 +1727,9 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
		if (!(file->f_mode & FMODE_WRITE) \|\| (file->f_flags & O_APPEND))
		return -EINVAL;

		if (btrfs_root_readonly(root))
		return -EROFS;

		ret = mnt_want_write(file->f_path.mnt);
		if (ret)
		return ret;
		@@ -1958,6 +2051,10 @@ static long btrfs_ioctl_trans_start(struct file *file)
		if (file->private_data)
		goto out;

		ret = -EROFS;
		if (btrfs_root_readonly(root))
		goto out;

		ret = mnt_want_write(file->f_path.mnt);
		if (ret)
		goto out;
		@@ -2257,13 +2354,17 @@ long btrfs_ioctl(struct file *file, unsigned int
		case FS_IOC_GETVERSION:
		return btrfs_ioctl_getversion(file, argp);
		case BTRFS_IOC_SNAP_CREATE:
		return btrfs_ioctl_snap_create(file, argp, 0, 0);
		return btrfs_ioctl_snap_create(file, argp, 0);
		case BTRFS_IOC_SNAP_CREATE_V2:
		return btrfs_ioctl_snap_create(file, argp, 0, 1);
		return btrfs_ioctl_snap_create_v2(file, argp, 0);
		case BTRFS_IOC_SUBVOL_CREATE:
		return btrfs_ioctl_snap_create(file, argp, 1, 0);
		return btrfs_ioctl_snap_create(file, argp, 1);
		case BTRFS_IOC_SNAP_DESTROY:
		return btrfs_ioctl_snap_destroy(file, argp);
		case BTRFS_IOC_SUBVOL_GETFLAGS:
		return btrfs_ioctl_subvol_getflags(file, argp);
		case BTRFS_IOC_SUBVOL_SETFLAGS:
		return btrfs_ioctl_subvol_setflags(file, argp);
		case BTRFS_IOC_DEFAULT_SUBVOL:
		return btrfs_ioctl_default_subvol(file, argp);
		case BTRFS_IOC_DEFRAG:

fs/btrfs/ioctl.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@ struct btrfs_ioctl_vol_args {
		};

		#define BTRFS_SUBVOL_CREATE_ASYNC (1ULL << 0)
		#define BTRFS_SUBVOL_RDONLY (1ULL << 1)

		#define BTRFS_SUBVOL_NAME_MAX 4039
		struct btrfs_ioctl_vol_args_v2 {
		@@ -193,4 +194,6 @@ struct btrfs_ioctl_space_args {
		#define BTRFS_IOC_WAIT_SYNC _IOW(BTRFS_IOCTL_MAGIC, 22, __u64)
		#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
		struct btrfs_ioctl_vol_args_v2)
		#define BTRFS_IOC_SUBVOL_GETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 25, __u64)
		#define BTRFS_IOC_SUBVOL_SETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 26, __u64)
		#endif

fs/btrfs/transaction.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -910,6 +910,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
		u64 to_reserve = 0;
		u64 index = 0;
		u64 objectid;
		u64 root_flags;

		new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
		if (!new_root_item) {
		@@ -967,6 +968,13 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
		btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
		memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));

		root_flags = btrfs_root_flags(new_root_item);
		if (pending->readonly)
		root_flags \|= BTRFS_ROOT_SUBVOL_RDONLY;
		else
		root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
		btrfs_set_root_flags(new_root_item, root_flags);

		old = btrfs_lock_root_node(root);
		btrfs_cow_block(trans, root, old, NULL, 0, &old);
		btrfs_set_lock_blocking(old);