From: Daeho Jeong <daehoje...@google.com>
Added a new ioctl to send discard commands to whole data area of
a regular file for security reason.
Signed-off-by: Daeho Jeong <daehoje...@google.com>
---
fs/f2fs/f2fs.h | 1 +
fs/f2fs/file.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 130 insertions(+)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c812fb8e2d9c..9ae81d0fefa0 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_TRIM_FILE _IO(F2FS_IOCTL_MAGIC, 20)
#define F2FS_IOC_GET_VOLUME_NAME FS_IOC_GETFSLABEL
#define F2FS_IOC_SET_VOLUME_NAME FS_IOC_SETFSLABEL
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index dfa1ac2d751a..58507bb5649c 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3749,6 +3749,132 @@ static int f2fs_reserve_compress_blocks(struct file
*filp, unsigned long arg)
return ret;
}
+static int f2fs_trim_file(struct file *filp)
+{
+ struct inode *inode = file_inode(filp);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct address_space *mapping = inode->i_mapping;
+ struct bio *bio = NULL;
+ 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;
+ int ret = 0;
+
+ if (!f2fs_hw_support_discard(sbi))
+ return -EOPNOTSUPP;
+
+ if (!S_ISREG(inode->i_mode) || f2fs_is_atomic_file(inode) ||
+ f2fs_compressed_file(inode))
+ return -EINVAL;
+
+ if (f2fs_readonly(sbi->sb))
+ return -EROFS;
+
+ 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 = __blkdev_issue_discard(prev_bdev,
+ SECTOR_FROM_BLOCK(prev_block),
+ SECTOR_FROM_BLOCK(len),
+ GFP_NOFS, 0, &bio);
+ if (ret)
+ goto out;
+
+ len = 0;
+ }
+ }
+
+ if (!len) {
+ prev_bdev = cur_bdev;
+ prev_block = blkaddr;
+ len = 1;
+ }
+ }
+
+ f2fs_put_dnode(&dn);
+ }
+
+ if (len)
+ ret = __blkdev_issue_discard(prev_bdev,
+ SECTOR_FROM_BLOCK(prev_block),
+ SECTOR_FROM_BLOCK(len),
+ GFP_NOFS, 0, &bio);
+out:
+ if (bio) {
+ ret = submit_bio_wait(bio);
+ bio_put(bio);
+ }
+
+ 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 +3961,8 @@ 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_TRIM_FILE:
+ return f2fs_trim_file(filp);
default:
return -ENOTTY;
}
@@ -4004,6 +4132,7 @@ 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_TRIM_FILE:
break;
default:
return -ENOIOCTLCMD;
--
2.27.0.278.ge193c7cf3a9-goog
