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f2fs: add F2FS_IOC_SEC_TRIM_FILE ioctl

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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 <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Daeho Jeong 2020-07-21 12:21:11 +09:00 committed by Jaegeuk Kim
parent b0f3b87fb3
commit 9af846486d
2 changed files with 206 additions and 0 deletions
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15
fs/f2fs/f2fs.h
View File

@ -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);

191
fs/f2fs/file.c
View File

@ -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;