Chao, > A little bit wired, why not failing cluster_may_compress() for user mode, and > let writepages write cluster as raw blocks, in-where we can update > i_compr_blocks > and global compr block stats correctly.
For decompression ioctl, I've made f2fs_need_compress_data() return "false" to prevent compression write, so we don't use f2fs_write_compressed_pages() anymore in this case. Because of this, I manually updated i_compr_blocks. Do you have any suggestions on this? 2020년 11월 26일 (목) 오후 2:04, Daeho Jeong <daeh...@gmail.com>님이 작성: > > Eric, > > do_page_cache_ra() is defined in mm/internal.h for internal use > between in mm, so we cannot use this one right now. > So, I think we could use page_cache_ra_unbounded(), because we already > check i_size boundary on our own. > What do you think? > > 2020년 11월 24일 (화) 오후 12:05, Chao Yu <yuch...@huawei.com>님이 작성: > > > > On 2020/11/23 11:17, Daeho Jeong wrote: > > > From: Daeho Jeong <daehoje...@google.com> > > > > > > Added two ioctl to decompress/compress explicitly the compression > > > enabled file in "compress_mode=user-based" mount option. > > > > > > Using these two ioctls, the users can make a control of compression > > > and decompression of their files. > > > > > > Signed-off-by: Daeho Jeong <daehoje...@google.com> > > > --- > > > fs/f2fs/file.c | 181 +++++++++++++++++++++++++++++++++++++- > > > include/uapi/linux/f2fs.h | 2 + > > > 2 files changed, 182 insertions(+), 1 deletion(-) > > > > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > > index be8db06aca27..e8f142470e87 100644 > > > --- a/fs/f2fs/file.c > > > +++ b/fs/f2fs/file.c > > > @@ -4026,6 +4026,180 @@ static int f2fs_ioc_set_compress_option(struct > > > file *filp, unsigned long arg) > > > return ret; > > > } > > > > > > +static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len) > > > +{ > > > + DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx); > > > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > > + struct address_space *mapping = inode->i_mapping; > > > + struct page *page; > > > + pgoff_t redirty_idx = page_idx; > > > + int i, page_len = 0, ret = 0; > > > + > > > + page_cache_ra_unbounded(&ractl, len, 0); > > > + > > > + for (i = 0; i < len; i++, page_idx++) { > > > + page = read_cache_page(mapping, page_idx, NULL, NULL); > > > + if (IS_ERR(page)) { > > > + ret = PTR_ERR(page); > > > + f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) " > > > + "couldn't be read (errno:%d).\n", > > > + __func__, inode->i_ino, page_idx, ret); > > > > This is a common error case during calling read_cache_page(), IMO, this > > looks > > more like a debug log, so I prefer to print nothing here, or at least using > > f2fs_debug() instead. > > > > > + break; > > > + } > > > + page_len++; > > > + } > > > + > > > + for (i = 0; i < page_len; i++, redirty_idx++) { > > > + page = find_lock_page(mapping, redirty_idx); > > > + if (!page) { > > > + ret = -ENOENT; > > > + f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) " > > > + "couldn't be found (errno:%d).\n", > > > + __func__, inode->i_ino, redirty_idx, ret); > > > > Ditto. > > > > > + } > > > + set_page_dirty(page); > > > + f2fs_put_page(page, 1); > > > + f2fs_put_page(page, 0); > > > + } > > > + > > > + return ret; > > > +} > > > + > > > +static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg) > > > +{ > > > + struct inode *inode = file_inode(filp); > > > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > > + struct f2fs_inode_info *fi = F2FS_I(inode); > > > + pgoff_t page_idx = 0, last_idx; > > > + int cluster_size = F2FS_I(inode)->i_cluster_size; > > > + int count, ret; > > > + > > > + if (!f2fs_sb_has_compression(sbi)) > > > + return -EOPNOTSUPP; > > > + > > > + if (!(filp->f_mode & FMODE_WRITE)) > > > + return -EBADF; > > > + > > > + if (!f2fs_compressed_file(inode)) > > > + return -EINVAL; > > > > Before compressubg/decompressing file, should we check whether current > > inode's > > compress algorithm backend is available in f2fs module? > > > > > + > > > + f2fs_balance_fs(F2FS_I_SB(inode), true); > > > + > > > + file_start_write(filp); > > > + inode_lock(inode); > > > + > > > + if (f2fs_is_mmap_file(inode)) { > > > + ret = -EBUSY; > > > + goto out; > > > + } > > > + > > > + ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX); > > > + if (ret) > > > + goto out; > > > + > > > + if (!atomic_read(&fi->i_compr_blocks)) > > > + goto out; > > > + > > > + last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); > > > + > > > + count = last_idx - page_idx; > > > + while (count) { > > > + int len = min(cluster_size, count); > > > + > > > + ret = redirty_blocks(inode, page_idx, len); > > > + > > > > unneeded blank line.. > > > > > + if (ret < 0) > > > + break; > > > + > > > + page_idx += len; > > > + count -= len; > > > > Considering there isn't so many memory in low-end device, how about calling > > filemap_fdatawrite() to writeback cluster after redirty several clusters > > or xxMB? > > > > > + } > > > + > > > + if (!ret) > > > + ret = filemap_write_and_wait_range(inode->i_mapping, 0, > > > + LLONG_MAX); > > > + > > > + if (!ret) { > > > + stat_sub_compr_blocks(inode, > > > atomic_read(&fi->i_compr_blocks)); > > > + atomic_set(&fi->i_compr_blocks, 0); > > > + f2fs_mark_inode_dirty_sync(inode, true); > > > > A little bit wired, why not failing cluster_may_compress() for user mode, > > and > > let writepages write cluster as raw blocks, in-where we can update > > i_compr_blocks > > and global compr block stats correctly. > > > > > + } else { > > > + f2fs_warn(sbi, "%s: The file might be partially > > > decompressed " > > > + "(errno=%d). Please delete the file.\n", > > > + __func__, ret); > > > + } > > > +out: > > > + inode_unlock(inode); > > > + file_end_write(filp); > > > + > > > + return ret; > > > +} > > > + > > > +static int f2fs_ioc_compress_file(struct file *filp, unsigned long arg) > > > +{ > > > + struct inode *inode = file_inode(filp); > > > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > > + pgoff_t page_idx = 0, last_idx; > > > + int cluster_size = F2FS_I(inode)->i_cluster_size; > > > + int count, ret; > > > + > > > + if (!f2fs_sb_has_compression(sbi)) > > > + return -EOPNOTSUPP; > > > + > > > + if (!(filp->f_mode & FMODE_WRITE)) > > > + return -EBADF; > > > + > > > + if (!f2fs_compressed_file(inode)) > > > + return -EINVAL; > > > > algorithm backend check? > > > > > + > > > + f2fs_balance_fs(F2FS_I_SB(inode), true); > > > + > > > + file_start_write(filp); > > > + inode_lock(inode); > > > + > > > + if (f2fs_is_mmap_file(inode)) { > > > + ret = -EBUSY; > > > + goto out; > > > + } > > > + > > > + ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX); > > > + if (ret) > > > + goto out; > > > + > > > + set_inode_flag(inode, FI_ENABLE_COMPRESS); > > > + > > > + last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); > > > + > > > + count = last_idx - page_idx; > > > + while (count) { > > > + int len = min(cluster_size, count); > > > + > > > + ret = redirty_blocks(inode, page_idx, len); > > > + > > > > Ditto. > > > > Thanks, > > > > > + if (ret < 0) > > > + break; > > > + > > > + page_idx += len; > > > + count -= len; > > > + } > > > + > > > + if (!ret) > > > + ret = filemap_write_and_wait_range(inode->i_mapping, 0, > > > + LLONG_MAX); > > > + > > > + clear_inode_flag(inode, FI_ENABLE_COMPRESS); > > > + > > > + if (ret) > > > + f2fs_warn(sbi, "%s: The file might be partially compressed " > > > + "(errno=%d). Please delete the file.\n", > > > + __func__, ret); > > > +out: > > > + inode_unlock(inode); > > > + file_end_write(filp); > > > + > > > + return ret; > > > +} > > > + > > > static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned > > > long arg) > > > { > > > switch (cmd) { > > > @@ -4113,6 +4287,10 @@ static long __f2fs_ioctl(struct file *filp, > > > unsigned int cmd, unsigned long arg) > > > return f2fs_ioc_get_compress_option(filp, arg); > > > case F2FS_IOC_SET_COMPRESS_OPTION: > > > return f2fs_ioc_set_compress_option(filp, arg); > > > + case F2FS_IOC_DECOMPRESS_FILE: > > > + return f2fs_ioc_decompress_file(filp, arg); > > > + case F2FS_IOC_COMPRESS_FILE: > > > + return f2fs_ioc_compress_file(filp, arg); > > > default: > > > return -ENOTTY; > > > } > > > @@ -4352,7 +4530,8 @@ long f2fs_compat_ioctl(struct file *file, unsigned > > > int cmd, unsigned long arg) > > > case F2FS_IOC_SEC_TRIM_FILE: > > > case F2FS_IOC_GET_COMPRESS_OPTION: > > > case F2FS_IOC_SET_COMPRESS_OPTION: > > > - break; > > > + case F2FS_IOC_DECOMPRESS_FILE: > > > + case F2FS_IOC_COMPRESS_FILE: > > > default: > > > return -ENOIOCTLCMD; > > > } > > > diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h > > > index f00199a2e38b..352a822d4370 100644 > > > --- a/include/uapi/linux/f2fs.h > > > +++ b/include/uapi/linux/f2fs.h > > > @@ -40,6 +40,8 @@ > > > struct f2fs_comp_option) > > > #define F2FS_IOC_SET_COMPRESS_OPTION _IOW(F2FS_IOCTL_MAGIC, 22, > > > \ > > > struct f2fs_comp_option) > > > +#define F2FS_IOC_DECOMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 23) > > > +#define F2FS_IOC_COMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 24) > > > > > > /* > > > * should be same as XFS_IOC_GOINGDOWN. > > >