[v2] erofs: refactor fast_symlink and read_inode

[PATCH V2 1/2] erofs: use kmemdup_nul in erofs_fill_symlink

Posted by Yiyang Wu 1 year, 3 months ago

Remove open coding in erofs_fill_symlink.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/all/20240425222847.GN2118490@ZenIV
Signed-off-by: Yiyang Wu <toolmanp@tlmp.cc>
---
 fs/erofs/inode.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 419432be3223..d051afe39670 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -188,22 +188,20 @@ static int erofs_fill_symlink(struct inode *inode, void *kaddr,
 		return 0;
 	}
 
-	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
-	if (!lnk)
-		return -ENOMEM;
-
 	m_pofs += vi->xattr_isize;
 	/* inline symlink data shouldn't cross block boundary */
 	if (m_pofs + inode->i_size > bsz) {
-		kfree(lnk);
 		erofs_err(inode->i_sb,
 			  "inline data cross block boundary @ nid %llu",
 			  vi->nid);
 		DBG_BUGON(1);
 		return -EFSCORRUPTED;
 	}
-	memcpy(lnk, kaddr + m_pofs, inode->i_size);
-	lnk[inode->i_size] = '\0';
+
+	lnk = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
+
+	if (!lnk)
+		return -ENOMEM;
 
 	inode->i_link = lnk;
 	inode->i_op = &erofs_fast_symlink_iops;
-- 
2.46.0

Re: [PATCH V2 1/2] erofs: use kmemdup_nul in erofs_fill_symlink

Posted by Gao Xiang 1 year, 3 months ago


On 2024/9/2 15:00, Yiyang Wu via Linux-erofs wrote:
> Remove open coding in erofs_fill_symlink.
> 
> Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
> Link: https://lore.kernel.org/all/20240425222847.GN2118490@ZenIV
> Signed-off-by: Yiyang Wu <toolmanp@tlmp.cc>
> ---
>   fs/erofs/inode.c | 12 +++++-------
>   1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index 419432be3223..d051afe39670 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -188,22 +188,20 @@ static int erofs_fill_symlink(struct inode *inode, void *kaddr,
>   		return 0;
>   	}
>   
> -	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
> -	if (!lnk)
> -		return -ENOMEM;
> -
>   	m_pofs += vi->xattr_isize;
>   	/* inline symlink data shouldn't cross block boundary */
>   	if (m_pofs + inode->i_size > bsz) {
> -		kfree(lnk);
>   		erofs_err(inode->i_sb,
>   			  "inline data cross block boundary @ nid %llu",
>   			  vi->nid);
>   		DBG_BUGON(1);
>   		return -EFSCORRUPTED;
>   	}
> -	memcpy(lnk, kaddr + m_pofs, inode->i_size);
> -	lnk[inode->i_size] = '\0';
> +
> +	lnk = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
> +

Unnecessary new line.

Also I wonder if it's possible to just
	inode->i_link = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
	if (!inode->i_link)
		return -ENOMEM;

here, and get rid of variable lnk.

Otherwise it looks good to me.

Thanks,
Gao Xiang

> +	if (!lnk)
> +		return -ENOMEM;
>   
>   	inode->i_link = lnk;
>   	inode->i_op = &erofs_fast_symlink_iops;

Re: [PATCH V2 1/2] erofs: use kmemdup_nul in erofs_fill_symlink

Posted by Yiyang Wu 1 year, 3 months ago

On Mon, Sep 02, 2024 at 03:11:45PM GMT, Gao Xiang wrote:

> 
> 
> On 2024/9/2 15:00, Yiyang Wu via Linux-erofs wrote:
> > Remove open coding in erofs_fill_symlink.
> > 
> > Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
> > Link: https://lore.kernel.org/all/20240425222847.GN2118490@ZenIV
> > Signed-off-by: Yiyang Wu <toolmanp@tlmp.cc>
> > ---
> >   fs/erofs/inode.c | 12 +++++-------
> >   1 file changed, 5 insertions(+), 7 deletions(-)
> > 
> > diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> > index 419432be3223..d051afe39670 100644
> > --- a/fs/erofs/inode.c
> > +++ b/fs/erofs/inode.c
> > @@ -188,22 +188,20 @@ static int erofs_fill_symlink(struct inode *inode, void *kaddr,
> >   		return 0;
> >   	}
> > -	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
> > -	if (!lnk)
> > -		return -ENOMEM;
> > -
> >   	m_pofs += vi->xattr_isize;
> >   	/* inline symlink data shouldn't cross block boundary */
> >   	if (m_pofs + inode->i_size > bsz) {
> > -		kfree(lnk);
> >   		erofs_err(inode->i_sb,
> >   			  "inline data cross block boundary @ nid %llu",
> >   			  vi->nid);
> >   		DBG_BUGON(1);
> >   		return -EFSCORRUPTED;
> >   	}
> > -	memcpy(lnk, kaddr + m_pofs, inode->i_size);
> > -	lnk[inode->i_size] = '\0';
> > +
> > +	lnk = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
> > +
> 
> Unnecessary new line.
> 
> Also I wonder if it's possible to just
> 	inode->i_link = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
> 	if (!inode->i_link)
> 		return -ENOMEM;
> 
> here, and get rid of variable lnk.
> 
> Otherwise it looks good to me.
> 
> Thanks,
> Gao Xiang
>  
Yeah, it looks good to me. Fixed.
> > +	if (!lnk)
> > +		return -ENOMEM;
> >   	inode->i_link = lnk;
> >   	inode->i_op = &erofs_fast_symlink_iops;
> 

Best Regards,
Yiyang Wu