Re: [f2fs-dev] [PATCH v5 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

From: Chao Yu
Date: Thu Oct 29 2020 - 03:58:33 EST


On 2020/10/29 15:39, Daeho Jeong wrote:
f2fs_cops is a static variable. Do you wanna change this to global
variable (extern)?

Oh, no, how about updating f2fs_is_compress_algorithm_ready() as below?
and use this function in f2fs_ioc_set_compress_option().

bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
{
return f2fs_cops[algorithm];
}


2020년 10월 29일 (목) 오후 4:29, Chao Yu <yuchao0@xxxxxxxxxx>님이 작성:

On 2020/10/29 12:15, Daeho Jeong wrote:
From: Daeho Jeong <daehojeong@xxxxxxxxxx>

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

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
=> 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size; => log scale cluster size
=> 2 ~ 8
};

struct f2fs_comp_option option;

option.algorithm = 1;
option.log_cluster_size = 7;

ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
---

v5: allowed to set algorithm which is not currently enabled by kernel
v4: changed commit message.
v3: changed the error number more specific.
folded in fix for build breakage reported by kernel test robot
<lkp@xxxxxxxxx> and Dan Carpenter <dan.carpenter@xxxxxxxxxx>.
v2: added ioctl description.
---
fs/f2fs/compress.c | 5 +++++
fs/f2fs/f2fs.h | 7 ++++++
fs/f2fs/file.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 66 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 7895186cc765..816d7adc914c 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
}

+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+ return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
+}
+
static mempool_t *compress_page_pool;
static int num_compress_pages = 512;
module_param(num_compress_pages, uint, 0444);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..cc38afde6c04 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.
@@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, void *fsdata,
int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
bool f2fs_is_compress_backend_ready(struct inode *inode);
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm);
int f2fs_init_compress_mempool(void);
void f2fs_destroy_compress_mempool(void);
void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
@@ -3945,6 +3948,10 @@ static inline bool f2fs_is_compress_backend_ready(struct inode *inode)
/* not support compression */
return false;
}
+static inline bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+ return false;
+}
static inline struct page *f2fs_compress_control_page(struct page *page)
{
WARN_ON_ONCE(1);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 8922ab191a9d..a0f31d8ebcfd 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,57 @@ 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 = 0;
+
+ 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)))
+ return -EFAULT;
+
+ if (!f2fs_compressed_file(inode) ||
+ option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+ option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
+ option.algorithm >= COMPRESS_MAX)
+ return -EINVAL;
+
+ file_start_write(filp);
+ inode_lock(inode);
+
+ if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (inode->i_size != 0) {
+ ret = -EFBIG;
+ goto out;
+ }

Hmm...

Shouldn't it be:

if (algorithm >= COMPRESS_MAX) {
ret = -ENOPKG;
goto out;
}

if (!f2fs_cops[algorithm])
f2fs_warn(...);

+
+ 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);
+
+ if (!f2fs_is_compress_algorithm_ready(option.algorithm))
+ f2fs_warn(sbi, "compression algorithm is successfully set, "
+ "but current kernel doesn't support this algorithm.");
+out:
+ 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)))))
@@ -4053,6 +4104,8 @@ 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 +4277,7 @@ 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;

.