Chao,
Do you want to print out a kernel warning message in this case? like
"XX compression algorithm is set for this inode, but current mount
option doesn't support this algorithm."?
2020년 10월 28일 (수) 오후 3:47, Chao Yu <yuch...@huawei.com>님이 작성:
>
> On 2020/10/27 13:38, Daeho Jeong wrote:
> > From: Daeho Jeong <daehoje...@google.com>
> >
> > 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 <daehoje...@google.com>
> > ---
> >
> > v4: changed commit message.
> > v3: changed the error number more specific.
> > folded in fix for build breakage reported by kernel test robot
> > <l...@intel.com> and Dan Carpenter <dan.carpen...@oracle.com>.
> > v2: added ioctl description.
> > ---
> > fs/f2fs/compress.c | 5 +++++
> > fs/f2fs/f2fs.h | 7 +++++++
> > fs/f2fs/file.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 64 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..8048b150e43b 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -3963,6 +3963,55 @@ 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)
> > + return -EINVAL;
> > +
> > + if (!f2fs_is_compress_algorithm_ready(option.algorithm))
> > + return -ENOPKG;
>
> As we allow to mount image with different kernel which supports different
> compress
> algorithms, so I guess we can support to change algorithm to one other which
> current
> kernel doesn't support, since we have add f2fs_is_compress_backend_ready() in
> all
> foreground operations to disallow user to operate such inode's data.
>
> IMO, just add to print one warnning message is fine.
>
> Thanks,
>
> > +
> > + 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;
> > + }
> > +
> > + 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);
> > + 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 +4102,8 @@ 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 +4275,7 @@ 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;
> >
