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Message-Id: <20200609060137.143501-1-daeho43@gmail.com>
Date: Tue, 9 Jun 2020 15:01:37 +0900
From: Daeho Jeong <daeho43@...il.com>
To: linux-kernel@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net, kernel-team@...roid.com
Cc: Daeho Jeong <daehojeong@...gle.com>
Subject: [PATCH] f2fs: add F2FS_IOC_SEC_TRIM_FILE ioctl
From: Daeho Jeong <daehojeong@...gle.com>
Added a new ioctl to send discard commands or/and zero out
to whole data area of a regular file for security reason.
Signed-off-by: Daeho Jeong <daehojeong@...gle.com>
---
fs/f2fs/f2fs.h | 8 +++
fs/f2fs/file.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 157 insertions(+)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c812fb8e2d9c..ca139fac5a73 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -434,6 +434,7 @@ 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, __u32)
#define F2FS_IOC_GET_VOLUME_NAME FS_IOC_GETFSLABEL
#define F2FS_IOC_SET_VOLUME_NAME FS_IOC_SETFSLABEL
@@ -453,6 +454,13 @@ 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
+
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
* ioctl commands in 32 bit emulation
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index dfa1ac2d751a..df5149a4a627 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3749,6 +3749,152 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
return ret;
}
+static int f2fs_secure_erase(struct block_device *bdev, 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)
+ 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;
+ loff_t file_size;
+ pgoff_t index, pg_start = 0, pg_end;
+ block_t prev_block = 0, len = 0;
+ u32 flags;
+ int ret = 0;
+
+ if (!S_ISREG(inode->i_mode) || f2fs_is_atomic_file(inode) ||
+ f2fs_compressed_file(inode))
+ return -EINVAL;
+
+ if (f2fs_readonly(sbi->sb))
+ return -EROFS;
+
+ if (f2fs_lfs_mode(sbi))
+ return -EOPNOTSUPP;
+
+ if (get_user(flags, (u32 __user *)arg))
+ return -EFAULT;
+ if (!(flags & F2FS_TRIM_FILE_MASK))
+ return -EINVAL;
+
+ if (flags & F2FS_TRIM_FILE_DISCARD && !f2fs_hw_support_discard(sbi))
+ return -EOPNOTSUPP;
+
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ inode_lock(inode);
+
+ file_size = i_size_read(inode);
+ if (!file_size)
+ goto err;
+ pg_end = (pgoff_t)round_up(file_size, PAGE_SIZE) >> PAGE_SHIFT;
+
+ 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(mapping);
+ if (ret)
+ goto out;
+
+ truncate_inode_pages(mapping, 0);
+
+ for (index = pg_start; index < pg_end;) {
+ struct dnode_of_data dn;
+ unsigned int end_offset;
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ ret = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
+ if (ret)
+ goto out;
+
+ end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
+ if (pg_end < end_offset + index)
+ end_offset = pg_end - index;
+
+ for (; dn.ofs_in_node < end_offset;
+ dn.ofs_in_node++, index++) {
+ struct block_device *cur_bdev;
+ block_t blkaddr = f2fs_data_blkaddr(&dn);
+
+ if (__is_valid_data_blkaddr(blkaddr)) {
+ if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode),
+ blkaddr, DATA_GENERIC_ENHANCE)) {
+ ret = -EFSCORRUPTED;
+ goto out;
+ }
+ } else
+ continue;
+
+ cur_bdev = f2fs_target_device(sbi, blkaddr, NULL);
+ if (f2fs_is_multi_device(sbi)) {
+ int i = f2fs_target_device_index(sbi, blkaddr);
+
+ blkaddr -= FDEV(i).start_blk;
+ }
+
+ if (len) {
+ if (prev_bdev == cur_bdev &&
+ blkaddr == prev_block + len) {
+ len++;
+ } else {
+ ret = f2fs_secure_erase(prev_bdev,
+ prev_block, len, flags);
+ if (ret)
+ goto out;
+
+ len = 0;
+ }
+ }
+
+ if (!len) {
+ prev_bdev = cur_bdev;
+ prev_block = blkaddr;
+ len = 1;
+ }
+ }
+
+ f2fs_put_dnode(&dn);
+ }
+
+ if (len)
+ ret = f2fs_secure_erase(prev_bdev, prev_block, len, flags);
+out:
+ up_write(&F2FS_I(inode)->i_mmap_sem);
+ up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+err:
+ inode_unlock(inode);
+ mnt_drop_write_file(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)))))
@@ -3835,6 +3981,8 @@ 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;
}
@@ -4004,6 +4152,7 @@ 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;
--
2.27.0.278.ge193c7cf3a9-goog
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