Commit 9af84648 authored by Daeho Jeong's avatar Daeho Jeong Committed by Jaegeuk Kim
Browse files

f2fs: add F2FS_IOC_SEC_TRIM_FILE ioctl 



Added a new ioctl to send discard commands or/and zero out
to selected data area of a regular file for security reason.

The way of handling range.len of F2FS_IOC_SEC_TRIM_FILE:
1. Added -1 value support for range.len to secure trim the whole blocks
   starting from range.start regardless of i_size.
2. If the end of the range passes over the end of file, it means until
   the end of file (i_size).
3. ignored the case of that range.len is zero to prevent the function
   from making end_addr zero and triggering different behaviour of
   the function.

Signed-off-by: default avatarDaeho Jeong <daehojeong@google.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent b0f3b87f

fs/f2fs/f2fs.h

+15 −0
Original line number Diff line number Diff line
@@ -430,6 +430,8 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal, 
					_IOR(F2FS_IOCTL_MAGIC, 18, __u64)

#define F2FS_IOC_RESERVE_COMPRESS_BLOCKS				\

					_IOR(F2FS_IOCTL_MAGIC, 19, __u64)

#define F2FS_IOC_SEC_TRIM_FILE		_IOW(F2FS_IOCTL_MAGIC, 20,	\

						struct f2fs_sectrim_range)



/*

 * should be same as XFS_IOC_GOINGDOWN.
@@ -442,6 +444,13 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal, 
#define F2FS_GOING_DOWN_METAFLUSH	0x3	/* going down with meta flush */

#define F2FS_GOING_DOWN_NEED_FSCK	0x4	/* going down to trigger fsck */



/*

 * Flags used by F2FS_IOC_SEC_TRIM_FILE

 */

#define F2FS_TRIM_FILE_DISCARD		0x1	/* send discard command */

#define F2FS_TRIM_FILE_ZEROOUT		0x2	/* zero out */

#define F2FS_TRIM_FILE_MASK		0x3



struct f2fs_gc_range {

	u32 sync;

	u64 start;
@@ -465,6 +474,12 @@ struct f2fs_flush_device { 
	u32 segments;		/* # of segments to flush */

};



struct f2fs_sectrim_range {

	u64 start;

	u64 len;

	u64 flags;

};



/* for inline stuff */

#define DEF_INLINE_RESERVED_SIZE	1

static inline int get_extra_isize(struct inode *inode);

fs/f2fs/file.c

+191 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/uuid.h>

#include <linux/file.h>

#include <linux/nls.h>

#include <linux/sched/signal.h>



#include "f2fs.h"

#include "node.h"
@@ -3759,6 +3760,193 @@ out: 
	return ret;

}



static int f2fs_secure_erase(struct block_device *bdev, struct inode *inode,

		pgoff_t off, block_t block, block_t len, u32 flags)

{

	struct request_queue *q = bdev_get_queue(bdev);

	sector_t sector = SECTOR_FROM_BLOCK(block);

	sector_t nr_sects = SECTOR_FROM_BLOCK(len);

	int ret = 0;



	if (!q)

		return -ENXIO;



	if (flags & F2FS_TRIM_FILE_DISCARD)

		ret = blkdev_issue_discard(bdev, sector, nr_sects, GFP_NOFS,

						blk_queue_secure_erase(q) ?

						BLKDEV_DISCARD_SECURE : 0);



	if (!ret && (flags & F2FS_TRIM_FILE_ZEROOUT)) {

		if (IS_ENCRYPTED(inode))

			ret = fscrypt_zeroout_range(inode, off, block, len);

		else

			ret = blkdev_issue_zeroout(bdev, sector, nr_sects,

					GFP_NOFS, 0);

	}



	return ret;

}



static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)

{

	struct inode *inode = file_inode(filp);

	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	struct address_space *mapping = inode->i_mapping;

	struct block_device *prev_bdev = NULL;

	struct f2fs_sectrim_range range;

	pgoff_t index, pg_end, prev_index = 0;

	block_t prev_block = 0, len = 0;

	loff_t end_addr;

	bool to_end = false;

	int ret = 0;



	if (!(filp->f_mode & FMODE_WRITE))

		return -EBADF;



	if (copy_from_user(&range, (struct f2fs_sectrim_range __user *)arg,

				sizeof(range)))

		return -EFAULT;



	if (range.flags == 0 || (range.flags & ~F2FS_TRIM_FILE_MASK) ||

			!S_ISREG(inode->i_mode))

		return -EINVAL;



	if (((range.flags & F2FS_TRIM_FILE_DISCARD) &&

			!f2fs_hw_support_discard(sbi)) ||

			((range.flags & F2FS_TRIM_FILE_ZEROOUT) &&

			 IS_ENCRYPTED(inode) && f2fs_is_multi_device(sbi)))

		return -EOPNOTSUPP;



	file_start_write(filp);

	inode_lock(inode);



	if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode) ||

			range.start >= inode->i_size) {

		ret = -EINVAL;

		goto err;

	}



	if (range.len == 0)

		goto err;



	if (inode->i_size - range.start > range.len) {

		end_addr = range.start + range.len;

	} else {

		end_addr = range.len == (u64)-1 ?

			sbi->sb->s_maxbytes : inode->i_size;

		to_end = true;

	}



	if (!IS_ALIGNED(range.start, F2FS_BLKSIZE) ||

			(!to_end && !IS_ALIGNED(end_addr, F2FS_BLKSIZE))) {

		ret = -EINVAL;

		goto err;

	}



	index = F2FS_BYTES_TO_BLK(range.start);

	pg_end = DIV_ROUND_UP(end_addr, F2FS_BLKSIZE);



	ret = f2fs_convert_inline_inode(inode);

	if (ret)

		goto err;



	down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

	down_write(&F2FS_I(inode)->i_mmap_sem);



	ret = filemap_write_and_wait_range(mapping, range.start,

			to_end ? LLONG_MAX : end_addr - 1);

	if (ret)

		goto out;



	truncate_inode_pages_range(mapping, range.start,

			to_end ? -1 : end_addr - 1);



	while (index < pg_end) {

		struct dnode_of_data dn;

		pgoff_t end_offset, count;

		int i;



		set_new_dnode(&dn, inode, NULL, NULL, 0);

		ret = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);

		if (ret) {

			if (ret == -ENOENT) {

				index = f2fs_get_next_page_offset(&dn, index);

				continue;

			}

			goto out;

		}



		end_offset = ADDRS_PER_PAGE(dn.node_page, inode);

		count = min(end_offset - dn.ofs_in_node, pg_end - index);

		for (i = 0; i < count; i++, index++, dn.ofs_in_node++) {

			struct block_device *cur_bdev;

			block_t blkaddr = f2fs_data_blkaddr(&dn);



			if (!__is_valid_data_blkaddr(blkaddr))

				continue;



			if (!f2fs_is_valid_blkaddr(sbi, blkaddr,

						DATA_GENERIC_ENHANCE)) {

				ret = -EFSCORRUPTED;

				f2fs_put_dnode(&dn);

				goto out;

			}



			cur_bdev = f2fs_target_device(sbi, blkaddr, NULL);

			if (f2fs_is_multi_device(sbi)) {

				int di = f2fs_target_device_index(sbi, blkaddr);



				blkaddr -= FDEV(di).start_blk;

			}



			if (len) {

				if (prev_bdev == cur_bdev &&

						index == prev_index + len &&

						blkaddr == prev_block + len) {

					len++;

				} else {

					ret = f2fs_secure_erase(prev_bdev,

						inode, prev_index, prev_block,

						len, range.flags);

					if (ret) {

						f2fs_put_dnode(&dn);

						goto out;

					}



					len = 0;

				}

			}



			if (!len) {

				prev_bdev = cur_bdev;

				prev_index = index;

				prev_block = blkaddr;

				len = 1;

			}

		}



		f2fs_put_dnode(&dn);



		if (fatal_signal_pending(current)) {

			ret = -EINTR;

			goto out;

		}

		cond_resched();

	}



	if (len)

		ret = f2fs_secure_erase(prev_bdev, inode, prev_index,

				prev_block, len, range.flags);

out:

	up_write(&F2FS_I(inode)->i_mmap_sem);

	up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

err:

	inode_unlock(inode);

	file_end_write(filp);



	return ret;

}



long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

{

	if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
@@ -3845,6 +4033,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
		return f2fs_release_compress_blocks(filp, arg);

	case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:

		return f2fs_reserve_compress_blocks(filp, arg);

	case F2FS_IOC_SEC_TRIM_FILE:

		return f2fs_sec_trim_file(filp, arg);

	default:

		return -ENOTTY;

	}
@@ -4014,6 +4204,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	case F2FS_IOC_GET_COMPRESS_BLOCKS:

	case F2FS_IOC_RELEASE_COMPRESS_BLOCKS:

	case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:

	case F2FS_IOC_SEC_TRIM_FILE:

		break;

	default:

		return -ENOIOCTLCMD;

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