From 9af846486d781a63de025a5f502c515268e48790 Mon Sep 17 00:00:00 2001 From: Daeho Jeong Date: Tue, 21 Jul 2020 12:21:11 +0900 Subject: [PATCH] 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: Daeho Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 15 ++++ fs/f2fs/file.c | 191 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 206 insertions(+) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 163fd5fadf11..3d9dd32a176a 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -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); diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 521987cd8772..cc7f5670390f 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -21,6 +21,7 @@ #include #include #include +#include #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; -- 2.25.1