[PATCH v4 6/6] f2fs: access compression level and flags by extra attr ioctls

[Sheng Yong]

Allow getting or setting compression level and flags through
F2FS_IOC_GET_EXTRA_ATTR and F2FS_IOC_SET_EXTRA_ATTR.

Signed-off-by: Sheng Yong <shengyong@xxxxxxxx>
---
 fs/f2fs/file.c            | 56 ++++++++++++++++++++++++++++++++-------
 include/uapi/linux/f2fs.h | 10 ++++++-
 2 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 39d04f8f0bb6b..1ac73cd59db79 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3916,10 +3916,14 @@ static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)
 	return ret;
 }
 
-static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+static int f2fs_get_compress_option_v2(struct file *filp,
+				       unsigned long attr, __u16 *attr_size)
 {
 	struct inode *inode = file_inode(filp);
-	struct f2fs_comp_option option;
+	struct f2fs_comp_option_v2 option;
+
+	if (sizeof(option) < *attr_size)
+		*attr_size = sizeof(option);
 
 	if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
 		return -EOPNOTSUPP;
@@ -3933,31 +3937,42 @@ static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
 
 	option.algorithm = F2FS_I(inode)->i_compress_algorithm;
 	option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
+	option.level = F2FS_I(inode)->i_compress_level;
+	option.flag = F2FS_I(inode)->i_compress_flag;
 
 	inode_unlock_shared(inode);
 
-	if (copy_to_user((struct f2fs_comp_option __user *)arg, &option,
-				sizeof(option)))
+	if (copy_to_user((void __user *)attr, &option, *attr_size))
 		return -EFAULT;
 
 	return 0;
 }
 
-static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+{
+	__u16 size = sizeof(struct f2fs_comp_option);
+
+	return f2fs_get_compress_option_v2(filp, arg, &size);
+}
+
+static int f2fs_set_compress_option_v2(struct file *filp,
+				       unsigned long attr, __u16 *attr_size)
 {
 	struct inode *inode = file_inode(filp);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-	struct f2fs_comp_option option;
+	struct f2fs_comp_option_v2 option;
 	int ret = 0;
 
+	if (sizeof(option) < *attr_size)
+		*attr_size = sizeof(option);
+
 	if (!f2fs_sb_has_compression(sbi))
 		return -EOPNOTSUPP;
 
 	if (!(filp->f_mode & FMODE_WRITE))
 		return -EBADF;
 
-	if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
-				sizeof(option)))
+	if (copy_from_user(&option, (void __user *)attr, *attr_size))
 		return -EFAULT;
 
 	if (!f2fs_compressed_file(inode) ||
@@ -3966,6 +3981,14 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
 			option.algorithm >= COMPRESS_MAX)
 		return -EINVAL;
 
+	if (*attr_size == sizeof(struct f2fs_comp_option_v2)) {
+		if (!f2fs_is_compress_level_valid(option.algorithm,
+						  option.level))
+			return -EINVAL;
+		if (option.flag > BIT(COMPRESS_MAX_FLAG) - 1)
+			return -EINVAL;
+	}
+
 	file_start_write(filp);
 	inode_lock(inode);
 
@@ -3982,6 +4005,10 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
 	F2FS_I(inode)->i_compress_algorithm = option.algorithm;
 	F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
 	F2FS_I(inode)->i_cluster_size = BIT(option.log_cluster_size);
+	if (*attr_size == sizeof(struct f2fs_comp_option_v2)) {
+		F2FS_I(inode)->i_compress_level = option.level;
+		F2FS_I(inode)->i_compress_flag = option.flag;
+	}
 	f2fs_mark_inode_dirty_sync(inode, true);
 
 	if (!f2fs_is_compress_backend_ready(inode))
@@ -3994,6 +4021,13 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+	__u16 size = sizeof(struct f2fs_comp_option);
+
+	return f2fs_set_compress_option_v2(filp, arg, &size);
+}
+
 static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
 {
 	DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, page_idx);
@@ -4277,7 +4311,8 @@ static int f2fs_ioc_get_extra_attr(struct file *filp, unsigned long arg)
 		ret = f2fs_get_compress_blocks(inode, &attr.attr);
 		break;
 	case F2FS_EXTRA_ATTR_COMPR_OPTION:
-		ret = f2fs_ioc_get_compress_option(filp, attr.attr);
+		ret = f2fs_get_compress_option_v2(filp, attr.attr,
+						  &attr.attr_size);
 		break;
 	default:
 		return -EINVAL;
@@ -4371,7 +4406,8 @@ static int f2fs_ioc_set_extra_attr(struct file *filp, unsigned long arg)
 			f2fs_balance_fs(sbi, true);
 		break;
 	case F2FS_EXTRA_ATTR_COMPR_OPTION:
-		ret = f2fs_ioc_set_compress_option(filp, attr.attr);
+		ret = f2fs_set_compress_option_v2(filp, attr.attr,
+						  &attr.attr_size);
 		break;
 	default:
 		return -EINVAL;
diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
index 2b53e90421bfc..153a6395c5f35 100644
--- a/include/uapi/linux/f2fs.h
+++ b/include/uapi/linux/f2fs.h
@@ -100,6 +100,13 @@ struct f2fs_comp_option {
 	__u8 log_cluster_size;
 };
 
+struct f2fs_comp_option_v2 {
+	__u8 algorithm;
+	__u8 log_cluster_size;
+	__u8 level;
+	__u8 flag;
+};
+
 enum {
 	F2FS_EXTRA_ATTR_TOTAL_SIZE,		/* ro, size of extra attr area */
 	F2FS_EXTRA_ATTR_ISIZE,			/* ro, i_extra_isize */
@@ -109,7 +116,8 @@ enum {
 	F2FS_EXTRA_ATTR_CRTIME,			/* ro, i_crtime, i_crtime_nsec */
 	F2FS_EXTRA_ATTR_COMPR_BLOCKS,		/* ro, i_compr_blocks */
 	F2FS_EXTRA_ATTR_COMPR_OPTION,		/* rw, i_compress_algorithm,
-						 *     i_log_cluster_size
+						 *     i_log_cluster_size,
+						 *     i_compress_flag
 						 */
 	F2FS_EXTRA_ATTR_MAX,
 };
-- 
2.40.1