| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <5b3cb83d-5d0f-c1ca-2cff-f28372dec48e@huawei.com>
Date: Tue, 24 Nov 2020 11:05:03 +0800
From: Chao Yu <yuchao0@...wei.com>
To: Daeho Jeong <daeho43@...il.com>, <linux-kernel@...r.kernel.org>,
<linux-f2fs-devel@...ts.sourceforge.net>, <kernel-team@...roid.com>
CC: Daeho Jeong <daehojeong@...gle.com>
Subject: Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and
F2FS_IOC_COMPRESS_FILE
On 2020/11/23 11:17, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@...gle.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 <daehojeong@...gle.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.
>
Powered by blists - more mailing lists