[PATCH v2] f2fs: fix to release inode page in get_new_data_page

[PATCH v2] f2fs: fix to release inode page in get_new_data_page

[Chao Yu]

In following call path, we will pass a locked and referenced ipage
pointer to get_new_data_page:
 - init_inode_metadata
  - make_empty_dir
   - get_new_data_page

There are two exit paths in get_new_data_page when error occurs:
1) grab_cache_page fails, ipage will not be released;
2) f2fs_reserve_block fails, ipage will be released in callee.

So, it's not consistent for error handling in get_new_data_page.

For f2fs_reserve_block, it's not very easy to change the rule
of error handling, since it's already complicated.

Here we deside to choose a easy way to fix this issue:
If any error occur in get_new_data_page, we will ensure releasing
ipage in this function.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
---
v2:
 * add comments in commit log and codes suggested by Jaegeuk.

 fs/f2fs/data.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 387d710..ddfc083 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -387,7 +387,8 @@ repeat:
  *
  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
  * f2fs_unlock_op().
- * Note that, ipage is set only by make_empty_dir.
+ * Note that, ipage is set only by make_empty_dir, and if any error occur,
+ * ipage should be released by this function.
  */
 struct page *get_new_data_page(struct inode *inode,
 		struct page *ipage, pgoff_t index, bool new_i_size)
@@ -398,8 +399,14 @@ struct page *get_new_data_page(struct inode *inode,
 	int err;
 repeat:
 	page = grab_cache_page(mapping, index);
-	if (!page)
+	if (!page) {
+		/*
+		 * before exiting, we should make sure ipage will be released
+		 * if any error occur.
+		 */
+		f2fs_put_page(ipage, 1);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	set_new_dnode(&dn, inode, ipage, NULL, 0);
 	err = f2fs_reserve_block(&dn, index);
-- 
2.4.2

RE: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page

[Chao Yu]

>From c0f2abda489150d5d458aaae9026f1243daea604 Mon Sep 17 00:00:00 2001
From: Chao Yu <chao2.yu@samsung.com>
Date: Tue, 14 Jul 2015 18:14:06 +0800
Subject: [PATCH v3] f2fs: fix to release inode page correctly

In following call path, we will pass a locked and referenced ipage
pointer to get_new_data_page:
 - init_inode_metadata
  - make_empty_dir
   - get_new_data_page

There are two exit paths in get_new_data_page when error occurs:
1) grab_cache_page fails, ipage will not be released;
2) f2fs_reserve_block fails, ipage will be released in callee.

So, it's not consistent for error handling in get_new_data_page.

For f2fs_reserve_block, it's not very easy to change the rule
of error handling, since it's already complicated.

Here we deside to choose an easy way to fix this issue:
If any error occur in get_new_data_page, we will ensure releasing
ipage in this function.

The same issue is in f2fs_convert_inline_dir, fix that too.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
---
v3:
 * fix the same issue in f2fs_convert_inline_dir.

 fs/f2fs/data.c   | 11 +++++++++--
 fs/f2fs/inline.c | 13 ++++++++++---
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e58562e..5da0529 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -387,7 +387,8 @@ repeat:
  *
  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
  * f2fs_unlock_op().
- * Note that, ipage is set only by make_empty_dir.
+ * Note that, ipage is set only by make_empty_dir, and if any error occur,
+ * ipage should be released by this function.
  */
 struct page *get_new_data_page(struct inode *inode,
 		struct page *ipage, pgoff_t index, bool new_i_size)
@@ -398,8 +399,14 @@ struct page *get_new_data_page(struct inode *inode,
 	int err;
 repeat:
 	page = grab_cache_page(mapping, index);
-	if (!page)
+	if (!page) {
+		/*
+		 * before exiting, we should make sure ipage will be released
+		 * if any error occur.
+		 */
+		f2fs_put_page(ipage, 1);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	set_new_dnode(&dn, inode, ipage, NULL, 0);
 	err = f2fs_reserve_block(&dn, index);
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index a13ffcc..79d18d5 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -360,6 +360,10 @@ int make_empty_inline_dir(struct inode *inode, struct inode *parent,
 	return 0;
 }
 
+/*
+ * NOTE: ipage is grabbed by caller, but if any error occurs, we should
+ * release ipage in this function.
+ */
 static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
 				struct f2fs_inline_dentry *inline_dentry)
 {
@@ -369,8 +373,10 @@ static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
 	int err;
 
 	page = grab_cache_page(dir->i_mapping, 0);
-	if (!page)
+	if (!page) {
+		f2fs_put_page(ipage, 1);
 		return -ENOMEM;
+	}
 
 	set_new_dnode(&dn, dir, ipage, NULL, 0);
 	err = f2fs_reserve_block(&dn, 0);
@@ -434,8 +440,9 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
 						slots, NR_INLINE_DENTRY);
 	if (bit_pos >= NR_INLINE_DENTRY) {
 		err = f2fs_convert_inline_dir(dir, ipage, dentry_blk);
-		if (!err)
-			err = -EAGAIN;
+		if (err)
+			return err;
+		err = -EAGAIN;
 		goto out;
 	}
 
-- 
2.4.2

RE: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page

[Chao Yu]

Hi Jaegeuk,

How about using v3 instead of v2 since it fixes the same type issue
in f2fs_convert_inline_dir?

Thanks,

> -----Original Message-----
> From: Chao Yu [mailto:chao2.yu@samsung.com]
> Sent: Monday, August 03, 2015 9:03 PM
> To: 'Jaegeuk Kim'
> Cc: linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net
> Subject: Re: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page
> 
> >From c0f2abda489150d5d458aaae9026f1243daea604 Mon Sep 17 00:00:00 2001
> From: Chao Yu <chao2.yu@samsung.com>
> Date: Tue, 14 Jul 2015 18:14:06 +0800
> Subject: [PATCH v3] f2fs: fix to release inode page correctly
> 
> In following call path, we will pass a locked and referenced ipage
> pointer to get_new_data_page:
>  - init_inode_metadata
>   - make_empty_dir
>    - get_new_data_page
> 
> There are two exit paths in get_new_data_page when error occurs:
> 1) grab_cache_page fails, ipage will not be released;
> 2) f2fs_reserve_block fails, ipage will be released in callee.
> 
> So, it's not consistent for error handling in get_new_data_page.
> 
> For f2fs_reserve_block, it's not very easy to change the rule
> of error handling, since it's already complicated.
> 
> Here we deside to choose an easy way to fix this issue:
> If any error occur in get_new_data_page, we will ensure releasing
> ipage in this function.
> 
> The same issue is in f2fs_convert_inline_dir, fix that too.
> 
> Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> ---
> v3:
>  * fix the same issue in f2fs_convert_inline_dir.
> 
>  fs/f2fs/data.c   | 11 +++++++++--
>  fs/f2fs/inline.c | 13 ++++++++++---
>  2 files changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index e58562e..5da0529 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -387,7 +387,8 @@ repeat:
>   *
>   * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
>   * f2fs_unlock_op().
> - * Note that, ipage is set only by make_empty_dir.
> + * Note that, ipage is set only by make_empty_dir, and if any error occur,
> + * ipage should be released by this function.
>   */
>  struct page *get_new_data_page(struct inode *inode,
>  		struct page *ipage, pgoff_t index, bool new_i_size)
> @@ -398,8 +399,14 @@ struct page *get_new_data_page(struct inode *inode,
>  	int err;
>  repeat:
>  	page = grab_cache_page(mapping, index);
> -	if (!page)
> +	if (!page) {
> +		/*
> +		 * before exiting, we should make sure ipage will be released
> +		 * if any error occur.
> +		 */
> +		f2fs_put_page(ipage, 1);
>  		return ERR_PTR(-ENOMEM);
> +	}
> 
>  	set_new_dnode(&dn, inode, ipage, NULL, 0);
>  	err = f2fs_reserve_block(&dn, index);
> diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
> index a13ffcc..79d18d5 100644
> --- a/fs/f2fs/inline.c
> +++ b/fs/f2fs/inline.c
> @@ -360,6 +360,10 @@ int make_empty_inline_dir(struct inode *inode, struct inode *parent,
>  	return 0;
>  }
> 
> +/*
> + * NOTE: ipage is grabbed by caller, but if any error occurs, we should
> + * release ipage in this function.
> + */
>  static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
>  				struct f2fs_inline_dentry *inline_dentry)
>  {
> @@ -369,8 +373,10 @@ static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
>  	int err;
> 
>  	page = grab_cache_page(dir->i_mapping, 0);
> -	if (!page)
> +	if (!page) {
> +		f2fs_put_page(ipage, 1);
>  		return -ENOMEM;
> +	}
> 
>  	set_new_dnode(&dn, dir, ipage, NULL, 0);
>  	err = f2fs_reserve_block(&dn, 0);
> @@ -434,8 +440,9 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
>  						slots, NR_INLINE_DENTRY);
>  	if (bit_pos >= NR_INLINE_DENTRY) {
>  		err = f2fs_convert_inline_dir(dir, ipage, dentry_blk);
> -		if (!err)
> -			err = -EAGAIN;
> +		if (err)
> +			return err;
> +		err = -EAGAIN;
>  		goto out;
>  	}
> 
> --
> 2.4.2
> 
> 
> 
> ------------------------------------------------------------------------------
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page

[Jaegeuk Kim]

On Wed, Aug 05, 2015 at 05:25:12PM +0800, Chao Yu wrote:
> Hi Jaegeuk,
> 
> How about using v3 instead of v2 since it fixes the same type issue
> in f2fs_convert_inline_dir?

Fixed.
Thanks,

> 
> Thanks,
> 
> > -----Original Message-----
> > From: Chao Yu [mailto:chao2.yu@samsung.com]
> > Sent: Monday, August 03, 2015 9:03 PM
> > To: 'Jaegeuk Kim'
> > Cc: linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net
> > Subject: Re: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page
> > 
> > >From c0f2abda489150d5d458aaae9026f1243daea604 Mon Sep 17 00:00:00 2001
> > From: Chao Yu <chao2.yu@samsung.com>
> > Date: Tue, 14 Jul 2015 18:14:06 +0800
> > Subject: [PATCH v3] f2fs: fix to release inode page correctly
> > 
> > In following call path, we will pass a locked and referenced ipage
> > pointer to get_new_data_page:
> >  - init_inode_metadata
> >   - make_empty_dir
> >    - get_new_data_page
> > 
> > There are two exit paths in get_new_data_page when error occurs:
> > 1) grab_cache_page fails, ipage will not be released;
> > 2) f2fs_reserve_block fails, ipage will be released in callee.
> > 
> > So, it's not consistent for error handling in get_new_data_page.
> > 
> > For f2fs_reserve_block, it's not very easy to change the rule
> > of error handling, since it's already complicated.
> > 
> > Here we deside to choose an easy way to fix this issue:
> > If any error occur in get_new_data_page, we will ensure releasing
> > ipage in this function.
> > 
> > The same issue is in f2fs_convert_inline_dir, fix that too.
> > 
> > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > ---
> > v3:
> >  * fix the same issue in f2fs_convert_inline_dir.
> > 
> >  fs/f2fs/data.c   | 11 +++++++++--
> >  fs/f2fs/inline.c | 13 ++++++++++---
> >  2 files changed, 19 insertions(+), 5 deletions(-)
> > 
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index e58562e..5da0529 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -387,7 +387,8 @@ repeat:
> >   *
> >   * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
> >   * f2fs_unlock_op().
> > - * Note that, ipage is set only by make_empty_dir.
> > + * Note that, ipage is set only by make_empty_dir, and if any error occur,
> > + * ipage should be released by this function.
> >   */
> >  struct page *get_new_data_page(struct inode *inode,
> >  		struct page *ipage, pgoff_t index, bool new_i_size)
> > @@ -398,8 +399,14 @@ struct page *get_new_data_page(struct inode *inode,
> >  	int err;
> >  repeat:
> >  	page = grab_cache_page(mapping, index);
> > -	if (!page)
> > +	if (!page) {
> > +		/*
> > +		 * before exiting, we should make sure ipage will be released
> > +		 * if any error occur.
> > +		 */
> > +		f2fs_put_page(ipage, 1);
> >  		return ERR_PTR(-ENOMEM);
> > +	}
> > 
> >  	set_new_dnode(&dn, inode, ipage, NULL, 0);
> >  	err = f2fs_reserve_block(&dn, index);
> > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
> > index a13ffcc..79d18d5 100644
> > --- a/fs/f2fs/inline.c
> > +++ b/fs/f2fs/inline.c
> > @@ -360,6 +360,10 @@ int make_empty_inline_dir(struct inode *inode, struct inode *parent,
> >  	return 0;
> >  }
> > 
> > +/*
> > + * NOTE: ipage is grabbed by caller, but if any error occurs, we should
> > + * release ipage in this function.
> > + */
> >  static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
> >  				struct f2fs_inline_dentry *inline_dentry)
> >  {
> > @@ -369,8 +373,10 @@ static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
> >  	int err;
> > 
> >  	page = grab_cache_page(dir->i_mapping, 0);
> > -	if (!page)
> > +	if (!page) {
> > +		f2fs_put_page(ipage, 1);
> >  		return -ENOMEM;
> > +	}
> > 
> >  	set_new_dnode(&dn, dir, ipage, NULL, 0);
> >  	err = f2fs_reserve_block(&dn, 0);
> > @@ -434,8 +440,9 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
> >  						slots, NR_INLINE_DENTRY);
> >  	if (bit_pos >= NR_INLINE_DENTRY) {
> >  		err = f2fs_convert_inline_dir(dir, ipage, dentry_blk);
> > -		if (!err)
> > -			err = -EAGAIN;
> > +		if (err)
> > +			return err;
> > +		err = -EAGAIN;
> >  		goto out;
> >  	}
> > 
> > --
> > 2.4.2
> > 
> > 
> > 
> > ------------------------------------------------------------------------------
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel