Esempio n. 1
0
/* open all lower files for a given file */
static int open_all_files(struct file *file)
{
	int bindex, bstart, bend, err = 0;
	struct file *lower_file;
	struct dentry *lower_dentry;
	struct dentry *dentry = file->f_path.dentry;
	struct super_block *sb = dentry->d_sb;

	bstart = dbstart(dentry);
	bend = dbend(dentry);

	for (bindex = bstart; bindex <= bend; bindex++) {
		lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
		if (!lower_dentry)
			continue;

		dget(lower_dentry);
		unionfs_mntget(dentry, bindex);
		branchget(sb, bindex);

		lower_file =
			dentry_open(lower_dentry,
				    unionfs_lower_mnt_idx(dentry, bindex),
				    file->f_flags, current_cred());
		if (IS_ERR(lower_file)) {
			branchput(sb, bindex);
			err = PTR_ERR(lower_file);
			goto out;
		} else {
			unionfs_set_lower_file_idx(file, bindex, lower_file);
		}
	}
out:
	return err;
}
Esempio n. 2
0
/*
 * put all references held by upper struct file and free lower file pointer
 * array
 */
static void cleanup_file(struct file *file)
{
	int bindex, bstart, bend;
	struct file **lower_files;
	struct file *lower_file;
	struct super_block *sb = file->f_path.dentry->d_sb;

	lower_files = UNIONFS_F(file)->lower_files;
	bstart = fbstart(file);
	bend = fbend(file);

	for (bindex = bstart; bindex <= bend; bindex++) {
		int i;	/* holds (possibly) updated branch index */
		int old_bid;

		lower_file = unionfs_lower_file_idx(file, bindex);
		if (!lower_file)
			continue;

		/*
		 * Find new index of matching branch with an open
		 * file, since branches could have been added or
		 * deleted causing the one with open files to shift.
		 */
		old_bid = UNIONFS_F(file)->saved_branch_ids[bindex];
		i = branch_id_to_idx(sb, old_bid);
		if (unlikely(i < 0)) {
			printk(KERN_ERR "unionfs: no superblock for "
			       "file %p\n", file);
			continue;
		}

		/* decrement count of open files */
		branchput(sb, i);
		/*
		 * fput will perform an mntput for us on the correct branch.
		 * Although we're using the file's old branch configuration,
		 * bindex, which is the old index, correctly points to the
		 * right branch in the file's branch list.  In other words,
		 * we're going to mntput the correct branch even if branches
		 * have been added/removed.
		 */
		fput(lower_file);
		UNIONFS_F(file)->lower_files[bindex] = NULL;
		UNIONFS_F(file)->saved_branch_ids[bindex] = -1;
	}

	UNIONFS_F(file)->lower_files = NULL;
	kfree(lower_files);
	kfree(UNIONFS_F(file)->saved_branch_ids);
	/* set to NULL because caller needs to know if to kfree on error */
	UNIONFS_F(file)->saved_branch_ids = NULL;
}
Esempio n. 3
0
/* perform a delayed copyup of a read-write file on a read-only branch */
static int do_delayed_copyup(struct file *file, struct dentry *parent)
{
	int bindex, bstart, bend, err = 0;
	struct dentry *dentry = file->f_path.dentry;
	struct inode *parent_inode = parent->d_inode;

	bstart = fbstart(file);
	bend = fbend(file);

	BUG_ON(!S_ISREG(dentry->d_inode->i_mode));

	unionfs_check_file(file);
	for (bindex = bstart - 1; bindex >= 0; bindex--) {
		if (!d_deleted(dentry))
			err = copyup_file(parent_inode, file, bstart,
					  bindex,
					  i_size_read(dentry->d_inode));
		else
			err = copyup_deleted_file(file, dentry, parent,
						  bstart, bindex);
		/* if succeeded, set lower open-file flags and break */
		if (!err) {
			struct file *lower_file;
			lower_file = unionfs_lower_file_idx(file, bindex);
			lower_file->f_flags = file->f_flags;
			break;
		}
	}
	if (err || (bstart <= fbstart(file)))
		goto out;
	bend = fbend(file);
	for (bindex = bstart; bindex <= bend; bindex++) {
		if (unionfs_lower_file_idx(file, bindex)) {
			branchput(dentry->d_sb, bindex);
			fput(unionfs_lower_file_idx(file, bindex));
			unionfs_set_lower_file_idx(file, bindex, NULL);
		}
	}
	path_put_lowers(dentry, bstart, bend, false);
	iput_lowers(dentry->d_inode, bstart, bend, false);
	/* for reg file, we only open it "once" */
	fbend(file) = fbstart(file);
	dbend(dentry) = dbstart(dentry);
	ibend(dentry->d_inode) = ibstart(dentry->d_inode);

out:
	unionfs_check_file(file);
	return err;
}
Esempio n. 4
0
int copyup_named_dentry(struct inode *dir, struct dentry *dentry,
			int bstart, int new_bindex, char *name,
			int namelen, struct file **copyup_file, int len)
{
	struct dentry *new_hidden_dentry;
	struct dentry *old_hidden_dentry = NULL;
	struct super_block *sb;
	struct file *input_file = NULL;
	struct file *output_file = NULL;
	ssize_t read_bytes, write_bytes;
	mm_segment_t old_fs;
	int err = 0;
	char *buf;
	int old_bindex;
	int got_branch_input = -1;
	int got_branch_output = -1;
	int old_bstart;
	int old_bend;
	int size = len;
	struct dentry *new_hidden_parent_dentry;
	mm_segment_t oldfs;
	char *symbuf = NULL;
	uid_t saved_uid = current->fsuid;
	gid_t saved_gid = current->fsgid;

	print_entry_location();
	verify_locked(dentry);
	fist_print_dentry("IN: copyup_named_dentry", dentry);

	old_bindex = bstart;
	old_bstart = dbstart(dentry);
	old_bend = dbend(dentry);

	ASSERT(new_bindex >= 0);
	ASSERT(new_bindex < old_bindex);
	PASSERT(dir);
	PASSERT(dentry);

	sb = dir->i_sb;

	if ((err = is_robranch_super(sb, new_bindex)))
		goto out;

	/* Create the directory structure above this dentry. */
	new_hidden_dentry = create_parents_named(dir, dentry, name, new_bindex);
	PASSERT(new_hidden_dentry);
	if (IS_ERR(new_hidden_dentry)) {
		err = PTR_ERR(new_hidden_dentry);
		goto out;
	}

	fist_print_generic_dentry("Copyup Object", new_hidden_dentry);

	/* Now we actually create the object. */
	old_hidden_dentry = dtohd_index(dentry, old_bindex);
	PASSERT(old_hidden_dentry);
	PASSERT(old_hidden_dentry->d_inode);
	DGET(old_hidden_dentry);

	/* For symlinks, we must read the link before we lock the directory. */
	if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) {
		PASSERT(old_hidden_dentry->d_inode->i_op);
		PASSERT(old_hidden_dentry->d_inode->i_op->readlink);

		symbuf = KMALLOC(PATH_MAX, GFP_UNIONFS);
		if (!symbuf) {
			err = -ENOMEM;
			goto copyup_readlink_err;
		}

		oldfs = get_fs();
		set_fs(KERNEL_DS);
		err =
		    old_hidden_dentry->d_inode->i_op->
		    readlink(old_hidden_dentry, symbuf, PATH_MAX);
		set_fs(oldfs);
		if (err < 0)
			goto copyup_readlink_err;
		symbuf[err] = '\0';
	}

	/* Now we lock the parent, and create the object in the new branch. */
	new_hidden_parent_dentry = lock_parent(new_hidden_dentry);
	current->fsuid = new_hidden_parent_dentry->d_inode->i_uid;
	current->fsgid = new_hidden_parent_dentry->d_inode->i_gid;
	if (S_ISDIR(old_hidden_dentry->d_inode->i_mode)) {
		err = vfs_mkdir(new_hidden_parent_dentry->d_inode,
				new_hidden_dentry, S_IRWXU);
	} else if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
		err = vfs_symlink(new_hidden_parent_dentry->d_inode,
				  new_hidden_dentry, symbuf);
#else
		err = vfs_symlink(new_hidden_parent_dentry->d_inode,
				  new_hidden_dentry, symbuf, S_IRWXU);
#endif
	} else if (S_ISBLK(old_hidden_dentry->d_inode->i_mode)
		   || S_ISCHR(old_hidden_dentry->d_inode->i_mode)
		   || S_ISFIFO(old_hidden_dentry->d_inode->i_mode)
		   || S_ISSOCK(old_hidden_dentry->d_inode->i_mode)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
		err = vfs_mknod(new_hidden_parent_dentry->d_inode,
				new_hidden_dentry,
				old_hidden_dentry->d_inode->i_mode,
				kdev_t_to_nr(old_hidden_dentry->d_inode->
					     i_rdev));
#else
		err = vfs_mknod(new_hidden_parent_dentry->d_inode,
				new_hidden_dentry,
				old_hidden_dentry->d_inode->i_mode,
				old_hidden_dentry->d_inode->i_rdev);
#endif
	} else if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
		err = vfs_create(new_hidden_parent_dentry->d_inode,
				 new_hidden_dentry, S_IRWXU);
#else
		err = vfs_create(new_hidden_parent_dentry->d_inode,
				 new_hidden_dentry, S_IRWXU, NULL);
#endif
	} else {
		char diemsg[100];
		snprintf(diemsg, sizeof(diemsg), "Unknown inode type %d\n",
			 old_hidden_dentry->d_inode->i_mode);
		FISTBUG(diemsg);
	}
	current->fsuid = saved_uid;
	current->fsgid = saved_gid;
	unlock_dir(new_hidden_parent_dentry);
      copyup_readlink_err:
	KFREE(symbuf);
	if (err) {
		/* get rid of the hidden dentry and all its traces */
		DPUT(new_hidden_dentry);
		set_dtohd_index(dentry, new_bindex, NULL);
		set_dbstart(dentry, old_bstart);
		set_dbend(dentry, old_bend);
		goto out;
	}

	/* We actually copyup the file here. */
	if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) {
		mntget(stohiddenmnt_index(sb, old_bindex));
		branchget(sb, old_bindex);
		got_branch_input = old_bindex;
		input_file =
		    DENTRY_OPEN(old_hidden_dentry,
				stohiddenmnt_index(sb, old_bindex), O_RDONLY);
		if (IS_ERR(input_file)) {
			err = PTR_ERR(input_file);
			goto out;
		}
		if (!input_file->f_op || !input_file->f_op->read) {
			err = -EINVAL;
			goto out;
		}

		/* copy the new file */
		DGET(new_hidden_dentry);
		mntget(stohiddenmnt_index(sb, new_bindex));
		branchget(sb, new_bindex);
		got_branch_output = new_bindex;
		output_file =
		    DENTRY_OPEN(new_hidden_dentry,
				stohiddenmnt_index(sb, new_bindex), O_WRONLY);
		if (IS_ERR(output_file)) {
			err = PTR_ERR(output_file);
			goto out;
		}
		if (!output_file->f_op || !output_file->f_op->write) {
			err = -EINVAL;
			goto out;
		}

		/* allocating a buffer */
		buf = (char *)KMALLOC(PAGE_SIZE, GFP_UNIONFS);
		if (!buf) {
			err = -ENOMEM;
			goto out;
		}

		/* now read PAGE_SIZE bytes from offset 0 in a loop */
		old_fs = get_fs();

		input_file->f_pos = 0;
		output_file->f_pos = 0;

		set_fs(KERNEL_DS);
		do {
			if (len >= PAGE_SIZE)
				size = PAGE_SIZE;
			else if ((len < PAGE_SIZE) && (len > 0))
				size = len;

			len -= PAGE_SIZE;

			read_bytes =
			    input_file->f_op->read(input_file, buf, size,
						   &input_file->f_pos);
			if (read_bytes <= 0) {
				err = read_bytes;
				break;
			}

			write_bytes =
			    output_file->f_op->write(output_file, buf,
						     read_bytes,
						     &output_file->f_pos);
			if (write_bytes < 0 || (write_bytes < read_bytes)) {
				err = -EIO;
				break;
			}
		} while ((read_bytes > 0) && (len > 0));
		set_fs(old_fs);
		KFREE(buf);
	}

	/* Set permissions. */
	if ((err =
	     copyup_permissions(sb, old_hidden_dentry, new_hidden_dentry)))
		goto out;
	/* Selinux uses extended attributes for permissions. */
#if defined(UNIONFS_XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
	if ((err = copyup_xattrs(old_hidden_dentry, new_hidden_dentry)))
		goto out;
#endif

	/* do not allow files getting deleted to be reinterposed */
	if (!d_deleted(dentry))
		unionfs_reinterpose(dentry);

      out:
	if (input_file && !IS_ERR(input_file)) {
		fput(input_file);
	} else {
		/* since input file was not opened, we need to explicitly
		 * dput the old_hidden_dentry
		 */
		DPUT(old_hidden_dentry);
	}

	/* in any case, we have to branchput */
	if (got_branch_input >= 0)
		branchput(sb, got_branch_input);

	if (output_file) {
		if (copyup_file && !err) {
			*copyup_file = output_file;
		} else {
			fput(output_file);
			branchput(sb, got_branch_output);
		}
	}

	fist_print_dentry("OUT: copyup_dentry", dentry);
	fist_print_inode("OUT: copyup_dentry", dentry->d_inode);

	print_exit_status(err);
	return err;
}
Esempio n. 5
0
/* Is a directory logically empty? */
int check_empty(struct dentry *dentry, struct dentry *parent,
		struct unionfs_dir_state **namelist)
{
	int err = 0;
	struct dentry *lower_dentry = NULL;
	struct vfsmount *mnt;
	struct super_block *sb;
	struct file *lower_file;
	struct unionfs_rdutil_callback *buf = NULL;
	int bindex, bstart, bend, bopaque;

	sb = dentry->d_sb;


	BUG_ON(!S_ISDIR(dentry->d_inode->i_mode));

	err = unionfs_partial_lookup(dentry, parent);
	if (err)
		goto out;

	bstart = dbstart(dentry);
	bend = dbend(dentry);
	bopaque = dbopaque(dentry);
	if (0 <= bopaque && bopaque < bend)
		bend = bopaque;

	buf = kmalloc(sizeof(struct unionfs_rdutil_callback), GFP_KERNEL);
	if (unlikely(!buf)) {
		err = -ENOMEM;
		goto out;
	}
	buf->err = 0;
	buf->mode = RD_CHECK_EMPTY;
	buf->rdstate = alloc_rdstate(dentry->d_inode, bstart);
	if (unlikely(!buf->rdstate)) {
		err = -ENOMEM;
		goto out;
	}

	/* Process the lower directories with rdutil_callback as a filldir. */
	for (bindex = bstart; bindex <= bend; bindex++) {
		lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
		if (!lower_dentry)
			continue;
		if (!lower_dentry->d_inode)
			continue;
		if (!S_ISDIR(lower_dentry->d_inode->i_mode))
			continue;

		dget(lower_dentry);
		mnt = unionfs_mntget(dentry, bindex);
		branchget(sb, bindex);
		lower_file = dentry_open(lower_dentry, mnt, O_RDONLY);
		if (IS_ERR(lower_file)) {
			err = PTR_ERR(lower_file);
			branchput(sb, bindex);
			goto out;
		}

		do {
			buf->filldir_called = 0;
			buf->rdstate->bindex = bindex;
			err = vfs_readdir(lower_file,
					  readdir_util_callback, buf);
			if (buf->err)
				err = buf->err;
		} while ((err >= 0) && buf->filldir_called);

		/* fput calls dput for lower_dentry */
		fput(lower_file);
		branchput(sb, bindex);

		if (err < 0)
			goto out;
	}

out:
	if (buf) {
		if (namelist && !err)
			*namelist = buf->rdstate;
		else if (buf->rdstate)
			free_rdstate(buf->rdstate);
		kfree(buf);
	}


	return err;
}
Esempio n. 6
0
/*
 * Copy up a dentry to a file of specified name.
 *
 * @dir: used to pull the ->i_sb to access other branches
 * @dentry: the non-negative dentry whose lower_inode we should copy
 * @bstart: the branch of the lower_inode to copy from
 * @new_bindex: the branch to create the new file in
 * @name: the name of the file to create
 * @namelen: length of @name
 * @copyup_file: the "struct file" to return (optional)
 * @len: how many bytes to copy-up?
 */
int copyup_dentry(struct inode *dir, struct dentry *dentry, int bstart,
		  int new_bindex, const char *name, int namelen,
		  struct file **copyup_file, loff_t len)
{
	struct dentry *new_lower_dentry;
	struct dentry *old_lower_dentry = NULL;
	struct super_block *sb;
	int err = 0;
	int old_bindex;
	int old_bstart;
	int old_bend;
	struct dentry *new_lower_parent_dentry = NULL;
	mm_segment_t oldfs;
	char *symbuf = NULL;

	verify_locked(dentry);

	old_bindex = bstart;
	old_bstart = dbstart(dentry);
	old_bend = dbend(dentry);

	BUG_ON(new_bindex < 0);
	BUG_ON(new_bindex >= old_bindex);

	sb = dir->i_sb;

	err = is_robranch_super(sb, new_bindex);
	if (err)
		goto out;

	/* Create the directory structure above this dentry. */
	new_lower_dentry = create_parents(dir, dentry, name, new_bindex);
	if (IS_ERR(new_lower_dentry)) {
		err = PTR_ERR(new_lower_dentry);
		goto out;
	}

	old_lower_dentry = unionfs_lower_dentry_idx(dentry, old_bindex);
	/* we conditionally dput this old_lower_dentry at end of function */
	dget(old_lower_dentry);

	/* For symlinks, we must read the link before we lock the directory. */
	if (S_ISLNK(old_lower_dentry->d_inode->i_mode)) {

		symbuf = kmalloc(PATH_MAX, GFP_KERNEL);
		if (unlikely(!symbuf)) {
			__clear(dentry, old_lower_dentry,
				old_bstart, old_bend,
				new_lower_dentry, new_bindex);
			err = -ENOMEM;
			goto out_free;
		}

		oldfs = get_fs();
		set_fs(KERNEL_DS);
		err = old_lower_dentry->d_inode->i_op->readlink(
			old_lower_dentry,
			(char __user *)symbuf,
			PATH_MAX);
		set_fs(oldfs);
		if (err < 0) {
			__clear(dentry, old_lower_dentry,
				old_bstart, old_bend,
				new_lower_dentry, new_bindex);
			goto out_free;
		}
		symbuf[err] = '\0';
	}

	/* Now we lock the parent, and create the object in the new branch. */
	new_lower_parent_dentry = lock_parent(new_lower_dentry);

	/* create the new inode */
	err = __copyup_ndentry(old_lower_dentry, new_lower_dentry,
			       new_lower_parent_dentry, symbuf);

	if (err) {
		__clear(dentry, old_lower_dentry,
			old_bstart, old_bend,
			new_lower_dentry, new_bindex);
		goto out_unlock;
	}

	/* We actually copyup the file here. */
	if (S_ISREG(old_lower_dentry->d_inode->i_mode))
		err = __copyup_reg_data(dentry, new_lower_dentry, new_bindex,
					old_lower_dentry, old_bindex,
					copyup_file, len);
	if (err)
		goto out_unlink;

	/* Set permissions. */
	err = copyup_permissions(sb, old_lower_dentry, new_lower_dentry);
	if (err)
		goto out_unlink;

#ifdef CONFIG_UNION_FS_XATTR
	/* Selinux uses extended attributes for permissions. */
	err = copyup_xattrs(old_lower_dentry, new_lower_dentry);
	if (err)
		goto out_unlink;
#endif /* CONFIG_UNION_FS_XATTR */

	/* do not allow files getting deleted to be re-interposed */
	if (!d_deleted(dentry))
		unionfs_reinterpose(dentry);

	goto out_unlock;

out_unlink:
	/*
	 * copyup failed, because we possibly ran out of space or
	 * quota, or something else happened so let's unlink; we don't
	 * really care about the return value of vfs_unlink
	 */
	vfs_unlink(new_lower_parent_dentry->d_inode, new_lower_dentry);

	if (copyup_file) {
		/* need to close the file */

		fput(*copyup_file);
		branchput(sb, new_bindex);
	}

	/*
	 * TODO: should we reset the error to something like -EIO?
	 *
	 * If we don't reset, the user may get some nonsensical errors, but
	 * on the other hand, if we reset to EIO, we guarantee that the user
	 * will get a "confusing" error message.
	 */

out_unlock:
	unlock_dir(new_lower_parent_dentry);

out_free:
	/*
	 * If old_lower_dentry was not a file, then we need to dput it.  If
	 * it was a file, then it was already dput indirectly by other
	 * functions we call above which operate on regular files.
	 */
	if (old_lower_dentry && old_lower_dentry->d_inode &&
	    !S_ISREG(old_lower_dentry->d_inode->i_mode))
		dput(old_lower_dentry);
	kfree(symbuf);

	if (err) {
		/*
		 * if directory creation succeeded, but inode copyup failed,
		 * then purge new dentries.
		 */
		if (dbstart(dentry) < old_bstart &&
		    ibstart(dentry->d_inode) > dbstart(dentry))
			__clear(dentry, NULL, old_bstart, old_bend,
				unionfs_lower_dentry(dentry), dbstart(dentry));
		goto out;
	}
	if (!S_ISDIR(dentry->d_inode->i_mode)) {
		unionfs_postcopyup_release(dentry);
		if (!unionfs_lower_inode(dentry->d_inode)) {
			/*
			 * If we got here, then we copied up to an
			 * unlinked-open file, whose name is .unionfsXXXXX.
			 */
			struct inode *inode = new_lower_dentry->d_inode;
			atomic_inc(&inode->i_count);
			unionfs_set_lower_inode_idx(dentry->d_inode,
						    ibstart(dentry->d_inode),
						    inode);
		}
	}
	unionfs_postcopyup_setmnt(dentry);
	/* sync inode times from copied-up inode to our inode */
	unionfs_copy_attr_times(dentry->d_inode);
	unionfs_check_inode(dir);
	unionfs_check_dentry(dentry);
out:
	return err;
}
Esempio n. 7
0
static int __copyup_reg_data(struct dentry *dentry,
			     struct dentry *new_lower_dentry, int new_bindex,
			     struct dentry *old_lower_dentry, int old_bindex,
			     struct file **copyup_file, loff_t len)
{
	struct super_block *sb = dentry->d_sb;
	struct file *input_file;
	struct file *output_file;
	struct vfsmount *output_mnt;
	mm_segment_t old_fs;
	char *buf = NULL;
	ssize_t read_bytes, write_bytes;
	loff_t size;
	int err = 0;

	/* open old file */
	unionfs_mntget(dentry, old_bindex);
	branchget(sb, old_bindex);
	/* dentry_open calls dput and mntput if it returns an error */
	input_file = dentry_open(old_lower_dentry,
				 unionfs_lower_mnt_idx(dentry, old_bindex),
				 O_RDONLY | O_LARGEFILE);
	if (IS_ERR(input_file)) {
		dput(old_lower_dentry);
		err = PTR_ERR(input_file);
		goto out;
	}
	if (unlikely(!input_file->f_op || !input_file->f_op->read)) {
		err = -EINVAL;
		goto out_close_in;
	}

	/* open new file */
	dget(new_lower_dentry);
	output_mnt = unionfs_mntget(sb->s_root, new_bindex);
	branchget(sb, new_bindex);
	output_file = dentry_open(new_lower_dentry, output_mnt,
				  O_RDWR | O_LARGEFILE);
	if (IS_ERR(output_file)) {
		err = PTR_ERR(output_file);
		goto out_close_in2;
	}
	if (unlikely(!output_file->f_op || !output_file->f_op->write)) {
		err = -EINVAL;
		goto out_close_out;
	}

	/* allocating a buffer */
	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (unlikely(!buf)) {
		err = -ENOMEM;
		goto out_close_out;
	}

	input_file->f_pos = 0;
	output_file->f_pos = 0;

	old_fs = get_fs();
	set_fs(KERNEL_DS);

	size = len;
	err = 0;
	do {
		if (len >= PAGE_SIZE)
			size = PAGE_SIZE;
		else if ((len < PAGE_SIZE) && (len > 0))
			size = len;

		len -= PAGE_SIZE;

		read_bytes =
			input_file->f_op->read(input_file,
					       (char __user *)buf, size,
					       &input_file->f_pos);
		if (read_bytes <= 0) {
			err = read_bytes;
			break;
		}

		/* see Documentation/filesystems/unionfs/issues.txt */
		lockdep_off();
		write_bytes =
			output_file->f_op->write(output_file,
						 (char __user *)buf,
						 read_bytes,
						 &output_file->f_pos);
		lockdep_on();
		if ((write_bytes < 0) || (write_bytes < read_bytes)) {
			err = write_bytes;
			break;
		}
	} while ((read_bytes > 0) && (len > 0));

	set_fs(old_fs);

	kfree(buf);

	if (!err)
		err = output_file->f_op->fsync(output_file,
					       new_lower_dentry, 0);

	if (err)
		goto out_close_out;

	if (copyup_file) {
		*copyup_file = output_file;
		goto out_close_in;
	}

out_close_out:
	fput(output_file);

out_close_in2:
	branchput(sb, new_bindex);

out_close_in:
	fput(input_file);

out:
	branchput(sb, old_bindex);

	return err;
}
Esempio n. 8
0
/* copy up a dentry to a file of specified name */
static int copyup_named_dentry(struct inode *dir, struct dentry *dentry,
			       int bstart, int new_bindex, const char *name,
			       int namelen, struct file **copyup_file,
			       loff_t len)
{
	struct dentry *new_hidden_dentry;
	struct dentry *old_hidden_dentry = NULL;
	struct super_block *sb;
	int err = 0;
	int old_bindex;
	int old_bstart;
	int old_bend;
	struct dentry *new_hidden_parent_dentry = NULL;
	mm_segment_t oldfs;
	char *symbuf = NULL;

	verify_locked(dentry);

	old_bindex = bstart;
	old_bstart = dbstart(dentry);
	old_bend = dbend(dentry);

	BUG_ON(new_bindex < 0);
	BUG_ON(new_bindex >= old_bindex);

	sb = dir->i_sb;

	unionfs_read_lock(sb);

	if ((err = is_robranch_super(sb, new_bindex))) {
		dput(old_hidden_dentry);
		goto out;
	}

	/* Create the directory structure above this dentry. */
	new_hidden_dentry = create_parents_named(dir, dentry, name, new_bindex);
	if (IS_ERR(new_hidden_dentry)) {
		dput(old_hidden_dentry);
		err = PTR_ERR(new_hidden_dentry);
		goto out;
	}

	old_hidden_dentry = unionfs_lower_dentry_idx(dentry, old_bindex);
	dget(old_hidden_dentry);

	/* For symlinks, we must read the link before we lock the directory. */
	if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) {

		symbuf = kmalloc(PATH_MAX, GFP_KERNEL);
		if (!symbuf) {
			__clear(dentry, old_hidden_dentry,
				old_bstart, old_bend,
				new_hidden_dentry, new_bindex);
			err = -ENOMEM;
			goto out_free;
		}

		oldfs = get_fs();
		set_fs(KERNEL_DS);
		err = old_hidden_dentry->d_inode->i_op->readlink(
					old_hidden_dentry,
					(char __user *)symbuf,
					PATH_MAX);
		set_fs(oldfs);
		if (err) {
			__clear(dentry, old_hidden_dentry,
				old_bstart, old_bend,
				new_hidden_dentry, new_bindex);
			goto out_free;
		}
		symbuf[err] = '\0';
	}

	/* Now we lock the parent, and create the object in the new branch. */
	new_hidden_parent_dentry = lock_parent(new_hidden_dentry);

	/* create the new inode */
	err = __copyup_ndentry(old_hidden_dentry, new_hidden_dentry,
			       new_hidden_parent_dentry, symbuf);

	if (err) {
		__clear(dentry, old_hidden_dentry,
			old_bstart, old_bend,
			new_hidden_dentry, new_bindex);
		goto out_unlock;
	}

	/* We actually copyup the file here. */
	if (S_ISREG(old_hidden_dentry->d_inode->i_mode))
		err = __copyup_reg_data(dentry, new_hidden_dentry, new_bindex,
				old_hidden_dentry, old_bindex, copyup_file, len);
	if (err)
		goto out_unlink;

	/* Set permissions. */
	if ((err = copyup_permissions(sb, old_hidden_dentry, new_hidden_dentry)))
		goto out_unlink;

#ifdef CONFIG_UNION_FS_XATTR
	/* Selinux uses extended attributes for permissions. */
	if ((err = copyup_xattrs(old_hidden_dentry, new_hidden_dentry)))
		goto out_unlink;
#endif

	/* do not allow files getting deleted to be reinterposed */
	if (!d_deleted(dentry))
		unionfs_reinterpose(dentry);

	goto out_unlock;
	/****/

out_unlink:
	/* copyup failed, because we possibly ran out of space or
	 * quota, or something else happened so let's unlink; we don't
	 * really care about the return value of vfs_unlink
	 */
	vfs_unlink(new_hidden_parent_dentry->d_inode, new_hidden_dentry);

	if (copyup_file) {
		/* need to close the file */

		fput(*copyup_file);
		branchput(sb, new_bindex);
	}

	/*
	 * TODO: should we reset the error to something like -EIO?
	 *
	 * If we don't reset, the user may get some non-sensical errors, but
	 * on the other hand, if we reset to EIO, we guarantee that the user
	 * will get a "confusing" error message.
	 */

out_unlock:
	unlock_dir(new_hidden_parent_dentry);

out_free:
	kfree(symbuf);

out:
	unionfs_read_unlock(sb);

	return err;
}
Esempio n. 9
0
static int __copyup_reg_data(struct dentry *dentry,
			     struct dentry *new_hidden_dentry, int new_bindex,
			     struct dentry *old_hidden_dentry, int old_bindex,
			     struct file **copyup_file, loff_t len)
{
	struct super_block *sb = dentry->d_sb;
	struct file *input_file;
	struct file *output_file;
	mm_segment_t old_fs;
	char *buf = NULL;
	ssize_t read_bytes, write_bytes;
	loff_t size;
	int err = 0;

	/* open old file */
	mntget(unionfs_lower_mnt_idx(dentry, old_bindex));
	branchget(sb, old_bindex);
	input_file = dentry_open(old_hidden_dentry,
				unionfs_lower_mnt_idx(dentry, old_bindex),
				O_RDONLY | O_LARGEFILE);
	if (IS_ERR(input_file)) {
		dput(old_hidden_dentry);
		err = PTR_ERR(input_file);
		goto out;
	}
	if (!input_file->f_op || !input_file->f_op->read) {
		err = -EINVAL;
		goto out_close_in;
	}

	/* open new file */
	dget(new_hidden_dentry);
	mntget(unionfs_lower_mnt_idx(dentry, new_bindex));
	branchget(sb, new_bindex);
	output_file = dentry_open(new_hidden_dentry,
				unionfs_lower_mnt_idx(dentry, new_bindex),
				O_WRONLY | O_LARGEFILE);
	if (IS_ERR(output_file)) {
		err = PTR_ERR(output_file);
		goto out_close_in2;
	}
	if (!output_file->f_op || !output_file->f_op->write) {
		err = -EINVAL;
		goto out_close_out;
	}

	/* allocating a buffer */
	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!buf) {
		err = -ENOMEM;
		goto out_close_out;
	}

	input_file->f_pos = 0;
	output_file->f_pos = 0;

	old_fs = get_fs();
	set_fs(KERNEL_DS);

	size = len;
	err = 0;
	do {
		if (len >= PAGE_SIZE)
			size = PAGE_SIZE;
		else if ((len < PAGE_SIZE) && (len > 0))
			size = len;

		len -= PAGE_SIZE;

		read_bytes =
		    input_file->f_op->read(input_file,
					   (char __user *)buf, size,
					   &input_file->f_pos);
		if (read_bytes <= 0) {
			err = read_bytes;
			break;
		}

		write_bytes =
		    output_file->f_op->write(output_file,
					     (char __user *)buf,
					     read_bytes,
					     &output_file->f_pos);
		if ((write_bytes < 0) || (write_bytes < read_bytes)) {
			err = write_bytes;
			break;
		}
	} while ((read_bytes > 0) && (len > 0));

	set_fs(old_fs);

	kfree(buf);

	if (err)
		goto out_close_out;
	if (copyup_file) {
		*copyup_file = output_file;
		goto out_close_in;
	}

out_close_out:
	fput(output_file);

out_close_in2:
	branchput(sb, new_bindex);

out_close_in:
	fput(input_file);

out:
	branchput(sb, old_bindex);

	return err;
}
Esempio n. 10
0
/*
 * release all lower object references & free the file info structure
 *
 * No need to grab sb info's rwsem.
 */
int unionfs_file_release(struct inode *inode, struct file *file)
{
	struct file *lower_file = NULL;
	struct unionfs_file_info *fileinfo;
	struct unionfs_inode_info *inodeinfo;
	struct super_block *sb = inode->i_sb;
	struct dentry *dentry = file->f_path.dentry;
	struct dentry *parent;
	int bindex, bstart, bend;
	int fgen, err = 0;

	/*
	 * Since mm/memory.c:might_fault() (under PROVE_LOCKING) was
	 * modified in 2.6.29-rc1 to call might_lock_read on mmap_sem, this
	 * has been causing false positives in file system stacking layers.
	 * In particular, our ->mmap is called after sys_mmap2 already holds
	 * mmap_sem, then we lock our own mutexes; but earlier, it's
	 * possible for lockdep to have locked our mutexes first, and then
	 * we call a lower ->readdir which could call might_fault.  The
	 * different ordering of the locks is what lockdep complains about
	 * -- unnecessarily.  Therefore, we have no choice but to tell
	 * lockdep to temporarily turn off lockdep here.  Note: the comments
	 * inside might_sleep also suggest that it would have been
	 * nicer to only annotate paths that needs that might_lock_read.
	 */
	lockdep_off();
	unionfs_read_lock(sb, UNIONFS_SMUTEX_PARENT);
	parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
	unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);

	/*
	 * We try to revalidate, but the VFS ignores return return values
	 * from file->release, so we must always try to succeed here,
	 * including to do the kfree and dput below.  So if revalidation
	 * failed, all we can do is print some message and keep going.
	 */
	err = unionfs_file_revalidate(file, parent,
				      UNIONFS_F(file)->wrote_to_file);
	if (!err)
		unionfs_check_file(file);
	fileinfo = UNIONFS_F(file);
	BUG_ON(file->f_path.dentry->d_inode != inode);
	inodeinfo = UNIONFS_I(inode);

	/* fput all the lower files */
	fgen = atomic_read(&fileinfo->generation);
	bstart = fbstart(file);
	bend = fbend(file);

	for (bindex = bstart; bindex <= bend; bindex++) {
		lower_file = unionfs_lower_file_idx(file, bindex);

		if (lower_file) {
			unionfs_set_lower_file_idx(file, bindex, NULL);
			fput(lower_file);
			branchput(sb, bindex);
		}

		/* if there are no more refs to the dentry, dput it */
		if (d_deleted(dentry)) {
			dput(unionfs_lower_dentry_idx(dentry, bindex));
			unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
		}
	}

	kfree(fileinfo->lower_files);
	kfree(fileinfo->saved_branch_ids);

	if (fileinfo->rdstate) {
		fileinfo->rdstate->access = jiffies;
		spin_lock(&inodeinfo->rdlock);
		inodeinfo->rdcount++;
		list_add_tail(&fileinfo->rdstate->cache,
			      &inodeinfo->readdircache);
		mark_inode_dirty(inode);
		spin_unlock(&inodeinfo->rdlock);
		fileinfo->rdstate = NULL;
	}
	kfree(fileinfo);

	unionfs_unlock_dentry(dentry);
	unionfs_unlock_parent(dentry, parent);
	unionfs_read_unlock(sb);
	lockdep_on();
	return err;
}
Esempio n. 11
0
int unionfs_open(struct inode *inode, struct file *file)
{
	int err = 0;
	struct file *lower_file = NULL;
	struct dentry *dentry = file->f_path.dentry;
	struct dentry *parent;
	int bindex = 0, bstart = 0, bend = 0;
	int size;
	int valid = 0;

	unionfs_read_lock(inode->i_sb, UNIONFS_SMUTEX_PARENT);
	parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
	unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);

	/* don't open unhashed/deleted files */
	if (d_deleted(dentry)) {
		err = -ENOENT;
		goto out_nofree;
	}

	/* XXX: should I change 'false' below to the 'willwrite' flag? */
	valid = __unionfs_d_revalidate(dentry, parent, false);
	if (unlikely(!valid)) {
		err = -ESTALE;
		goto out_nofree;
	}

	file->private_data =
		kzalloc(sizeof(struct unionfs_file_info), GFP_KERNEL);
	if (unlikely(!UNIONFS_F(file))) {
		err = -ENOMEM;
		goto out_nofree;
	}
	fbstart(file) = -1;
	fbend(file) = -1;
	atomic_set(&UNIONFS_F(file)->generation,
		   atomic_read(&UNIONFS_I(inode)->generation));

	size = sizeof(struct file *) * sbmax(inode->i_sb);
	UNIONFS_F(file)->lower_files = kzalloc(size, GFP_KERNEL);
	if (unlikely(!UNIONFS_F(file)->lower_files)) {
		err = -ENOMEM;
		goto out;
	}
	size = sizeof(int) * sbmax(inode->i_sb);
	UNIONFS_F(file)->saved_branch_ids = kzalloc(size, GFP_KERNEL);
	if (unlikely(!UNIONFS_F(file)->saved_branch_ids)) {
		err = -ENOMEM;
		goto out;
	}

	bstart = fbstart(file) = dbstart(dentry);
	bend = fbend(file) = dbend(dentry);

	/*
	 * open all directories and make the unionfs file struct point to
	 * these lower file structs
	 */
	if (S_ISDIR(inode->i_mode))
		err = __open_dir(inode, file);	/* open a dir */
	else
		err = __open_file(inode, file, parent);	/* open a file */

	/* freeing the allocated resources, and fput the opened files */
	if (err) {
		for (bindex = bstart; bindex <= bend; bindex++) {
			lower_file = unionfs_lower_file_idx(file, bindex);
			if (!lower_file)
				continue;

			branchput(dentry->d_sb, bindex);
			/* fput calls dput for lower_dentry */
			fput(lower_file);
		}
	}

out:
	if (err) {
		kfree(UNIONFS_F(file)->lower_files);
		kfree(UNIONFS_F(file)->saved_branch_ids);
		kfree(UNIONFS_F(file));
	}
out_nofree:
	if (!err) {
		unionfs_postcopyup_setmnt(dentry);
		unionfs_copy_attr_times(inode);
		unionfs_check_file(file);
		unionfs_check_inode(inode);
	}
	unionfs_unlock_dentry(dentry);
	unionfs_unlock_parent(dentry, parent);
	unionfs_read_unlock(inode->i_sb);
	return err;
}
Esempio n. 12
0
/* Is a directory logically empty? */
int check_empty(struct dentry *dentry, struct dentry *parent,
		struct unionfs_dir_state **namelist)
{
	int err = 0;
	struct dentry *lower_dentry = NULL;
	struct vfsmount *mnt;
	struct super_block *sb;
	struct file *lower_file;
	struct unionfs_rdutil_callback buf = {
		.ctx.actor = readdir_util_callback,
	};
	int bindex, bstart, bend, bopaque;
	struct path path;

	sb = dentry->d_sb;


	BUG_ON(!S_ISDIR(dentry->d_inode->i_mode));

	err = unionfs_partial_lookup(dentry, parent);
	if (err)
		goto out;

	bstart = dbstart(dentry);
	bend = dbend(dentry);
	bopaque = dbopaque(dentry);
	if (0 <= bopaque && bopaque < bend)
		bend = bopaque;

	buf.err = 0;
	buf.filldir_called = 0;
	buf.mode = RD_CHECK_EMPTY;
	buf.ctx.pos = 0; /* XXX: needed?! */
	buf.rdstate = alloc_rdstate(dentry->d_inode, bstart);
	if (unlikely(!buf.rdstate)) {
		err = -ENOMEM;
		goto out;
	}

	/* Process the lower directories with rdutil_callback as a filldir. */
	for (bindex = bstart; bindex <= bend; bindex++) {
		lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
		if (!lower_dentry)
			continue;
		if (!lower_dentry->d_inode)
			continue;
		if (!S_ISDIR(lower_dentry->d_inode->i_mode))
			continue;

		dget(lower_dentry);
		mnt = unionfs_mntget(dentry, bindex);
		branchget(sb, bindex);
		path.dentry = lower_dentry;
		path.mnt = mnt;
		lower_file = dentry_open(&path, O_RDONLY, current_cred());
		path_put(&path);
		if (IS_ERR(lower_file)) {
			err = PTR_ERR(lower_file);
			branchput(sb, bindex);
			goto out;
		}

		do {
			buf.filldir_called = 0;
			buf.rdstate->bindex = bindex;
			err = iterate_dir(lower_file, &buf.ctx);
			if (buf.err)
				err = buf.err;
		} while ((err >= 0) && buf.filldir_called);

		/* fput calls dput for lower_dentry */
		fput(lower_file);
		branchput(sb, bindex);

		if (err < 0)
			goto out;
	}

out:
	if (namelist && !err)
		*namelist = buf.rdstate;
	else if (buf.rdstate)
		free_rdstate(buf.rdstate);

	return err;
}