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From:   Daeho Jeong <daeho43@gmail.com>
To:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc:     Daeho Jeong <daehojeong@google.com>
Subject: [PATCH 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl
Date:   Tue, 13 Oct 2020 11:24:29 +0900
Message-Id: <20201013022429.454161-2-daeho43@gmail.com>
In-Reply-To: <20201013022429.454161-1-daeho43@gmail.com>
References: <20201013022429.454161-1-daeho43@gmail.com>
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From: Daeho Jeong <daehojeong@google.com>

Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
compression option of a file.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
 fs/f2fs/f2fs.h |  2 ++
 fs/f2fs/file.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..5ee8a4859b62 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION	_IOR(F2FS_IOCTL_MAGIC, 21,	\
 						struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION	_IOW(F2FS_IOCTL_MAGIC, 22,	\
+						struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 7e64259f6f5e..6c265c66ddd4 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,59 @@ static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
 	return 0;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_comp_option option;
+	int ret;
+	int writecount;
+
+	if (!f2fs_sb_has_compression(sbi))
+		return -EOPNOTSUPP;
+
+	if (!f2fs_compressed_file(inode) || IS_IMMUTABLE(inode))
+		return -EINVAL;
+
+	if (f2fs_readonly(sbi->sb))
+		return -EROFS;
+
+	if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
+				sizeof(option)))
+		return -EFAULT;
+
+	if (option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+			option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
+			option.algorithm >= COMPRESS_MAX)
+		return -EINVAL;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	writecount = atomic_read(&inode->i_writecount);
+	if ((filp->f_mode & FMODE_WRITE && writecount != 1) ||
+			(!(filp->f_mode & FMODE_WRITE) && writecount)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (get_dirty_pages(inode) || inode->i_size) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	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 = 1 << option.log_cluster_size;
+	f2fs_mark_inode_dirty_sync(inode, true);
+out:
+	inode_unlock(inode);
+	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)))))
@@ -4053,6 +4106,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_sec_trim_file(filp, arg);
 	case F2FS_IOC_GET_COMPRESS_OPTION:
 		return f2fs_ioc_get_compress_option(filp, arg);
+	case F2FS_IOC_SET_COMPRESS_OPTION:
+		return f2fs_ioc_set_compress_option(filp, arg);
 	default:
 		return -ENOTTY;
 	}
@@ -4224,6 +4279,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:
 	case F2FS_IOC_SEC_TRIM_FILE:
 	case F2FS_IOC_GET_COMPRESS_OPTION:
+	case F2FS_IOC_SET_COMPRESS_OPTION:
 		break;
 	default:
 		return -ENOIOCTLCMD;
-- 
2.28.0.1011.ga647a8990f-goog