Re: [PATCH 1/2] f2fs: compress: fix to disallow wildcard extension for hot/cold file

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 05/20, Chao Yu wrote:
> On 2021/5/20 10:21, Jaegeuk Kim wrote:
> > On 05/18, Chao Yu wrote:
> > > If all files are hot or cold, hot/cold separation is not needed anymore,
> > > so let's disallow configure wildcard extension.
> > 
> > We need to be able to set hot/cold on the fly?
> 
> I got your concern, so do you prefer to keep "*" extension configuration
> for hot/cold file?

I'm fine with "*".

> 
> Thanks,
> 
> > 
> > > 
> > > Fixes: 4c8ff7095bef ("f2fs: support data compression")
> > > Signed-off-by: Chao Yu <yuchao0@huawei.com>
> > > ---
> > >   fs/f2fs/f2fs.h  |  1 +
> > >   fs/f2fs/namei.c | 12 ++++++++----
> > >   fs/f2fs/sysfs.c |  3 +++
> > >   3 files changed, 12 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > > index b753cc88c77e..ecb13c3b458d 100644
> > > --- a/fs/f2fs/f2fs.h
> > > +++ b/fs/f2fs/f2fs.h
> > > @@ -3322,6 +3322,7 @@ void f2fs_handle_failed_inode(struct inode *inode);
> > >   /*
> > >    * namei.c
> > >    */
> > > +bool f2fs_is_wildcard_char(const char *ext);
> > >   int f2fs_update_extension_list(struct f2fs_sb_info *sbi, const char *name,
> > >   							bool hot, bool set);
> > >   struct dentry *f2fs_get_parent(struct dentry *child);
> > > diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> > > index a9cd9cf97229..8d78b96a8b3b 100644
> > > --- a/fs/f2fs/namei.c
> > > +++ b/fs/f2fs/namei.c
> > > @@ -153,15 +153,17 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
> > >   	return ERR_PTR(err);
> > >   }
> > > +bool f2fs_is_wildcard_char(const char *ext)
> > > +{
> > > +	return *ext == '*' && strlen(ext) == 1;
> > > +}
> > > +
> > >   static inline int is_extension_exist(const unsigned char *s, const char *sub)
> > >   {
> > >   	size_t slen = strlen(s);
> > >   	size_t sublen = strlen(sub);
> > >   	int i;
> > > -	if (sublen == 1 && *sub == '*')
> > > -		return 1;
> > > -
> > >   	/*
> > >   	 * filename format of multimedia file should be defined as:
> > >   	 * "filename + '.' + extension + (optional: '.' + temp extension)".
> > > @@ -306,9 +308,11 @@ static void set_compress_inode(struct f2fs_sb_info *sbi, struct inode *inode,
> > >   	ext = F2FS_OPTION(sbi).extensions;
> > >   	for (i = 0; i < ext_cnt; i++) {
> > > +		if (f2fs_is_wildcard_char(ext[i]))
> > > +			goto set_compress;
> > >   		if (!is_extension_exist(name, ext[i]))
> > >   			continue;
> > > -
> > > +set_compress:
> > >   		set_compress_context(inode);
> > >   		return;
> > >   	}
> > > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > > index dc71bc968c72..ff5acb4de1b6 100644
> > > --- a/fs/f2fs/sysfs.c
> > > +++ b/fs/f2fs/sysfs.c
> > > @@ -343,6 +343,9 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
> > >   		if (strlen(name) >= F2FS_EXTENSION_LEN)
> > >   			return -EINVAL;
> > > +		if (f2fs_is_wildcard_char(name))
> > > +			return -EINVAL;
> > > +
> > >   		down_write(&sbi->sb_lock);
> > >   		ret = f2fs_update_extension_list(sbi, name, hot, set);
> > > -- 
> > > 2.29.2
> > .
> >