f2fs: fix to release inode page in get_new_data_page

PATCH In review Chao Yu 2 participants 4 messages Jul 14, 2015 – Aug 5, 2015 F2FS file system

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Chao Yu

author

2015-07-14 10:14 UTC #0 lore raw

PATCH v2 1/1 f2fs: fix to release inode page in get_new_data_page

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 <[email protected]>

---
v2:
* add comments in commit log and codes suggested by Jaegeuk.

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

fs/f2fs/data.c +9 -2

index 387d710..ddfc083 100644
@@ -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);

Signature · 1 line

2.4.2

Chao Yu

author

2015-08-03 13:03 UTC #1 lore raw

Quoted 1 line

From c0f2abda489150d5d458aaae9026f1243daea604 Mon Sep 17 00:00:00 2001

From: Chao Yu <[email protected]>
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 <[email protected]>

---
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(-)

fs/f2fs/data.c +9 -2

index e58562e..5da0529 100644
@@ -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);

fs/f2fs/inline.c +10 -3

index a13ffcc..79d18d5 100644
@@ -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;
 	}

Signature · 1 line

2.4.2

Chao Yu

author

2015-08-05 09:25 UTC #2 lore raw

Hi Jaegeuk,

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

Thanks,

Quoted 121 lines

-----Original Message-----
From: Chao Yu [mailto:[email protected]]
Sent: Monday, August 03, 2015 9:03 PM
To: 'Jaegeuk Kim'
Cc: [email protected]; [email protected]
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page
Quoted 1 line
From c0f2abda489150d5d458aaae9026f1243daea604 Mon Sep 17 00:00:00 2001
From: Chao Yu <[email protected]>
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 <[email protected]>
---
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(-)
fs/f2fs/data.c +9 -2
index e58562e..5da0529 100644
@@ -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);
fs/f2fs/inline.c +10 -4
index a13ffcc..79d18d5 100644
@@ -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
------------------------------------------------------------------------------
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Linux-f2fs-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Jaegeuk Kim

maintainer

2015-08-05 15:12 UTC #3 lore raw

Quoted 4 lines · Chao Yu

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

Fixed.
Thanks,

Quoted 124 lines

Thanks,
Quoted 121 lines
-----Original Message-----
From: Chao Yu [mailto:[email protected]]
Sent: Monday, August 03, 2015 9:03 PM
To: 'Jaegeuk Kim'
Cc: [email protected]; [email protected]
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: fix to release inode page in get_new_data_page
Quoted 1 line
From c0f2abda489150d5d458aaae9026f1243daea604 Mon Sep 17 00:00:00 2001
From: Chao Yu <[email protected]>
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 <[email protected]>
---
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(-)
fs/f2fs/data.c +9 -2
index e58562e..5da0529 100644
@@ -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);
fs/f2fs/inline.c +10 -4
index a13ffcc..79d18d5 100644
@@ -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
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel