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* [PATCH] fs: Convert return type int to vm_fault_t
@ 2018-08-28 19:25 Souptick Joarder
  2018-08-30  7:56 ` Ryusuke Konishi
  0 siblings, 1 reply; 3+ messages in thread
From: Souptick Joarder @ 2018-08-28 19:25 UTC (permalink / raw)
  To: willy, viro, tytso, adilger.kernel, konishi.ryusuke,
	darrick.wong, axboe, ebiggers, tglx, gregkh, kemi.wang, akpm
  Cc: linux-fsdevel, linux-kernel, linux-ext4, linux-nilfs

Return type for fault handlers  in ext4 and nilfs are
changed to use vm_fault_t.

Return type of block_page_mkwrite() is changed from
int to vm_fault_t. The function signature of
block_page_mkwrite() is changed to add one new parameter
int *err. This will provide a way for caller functions
to get error number along with VM_FAULT return value and
use it further.

Return type of block_page_mkwrite_return() is also changed
to use new vm_fault_t type.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
---
 fs/buffer.c                 | 20 +++++++++++---------
 fs/ext4/ext4.h              |  4 ++--
 fs/ext4/inode.c             | 34 ++++++++++++++++++----------------
 fs/nilfs2/file.c            | 16 ++++++++++------
 include/linux/buffer_head.h |  7 ++++---
 5 files changed, 45 insertions(+), 36 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index ebf78ab..aacfc73 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2487,21 +2487,21 @@ int block_commit_write(struct page *page, unsigned from, unsigned to)
  * Direct callers of this function should protect against filesystem freezing
  * using sb_start_pagefault() - sb_end_pagefault() functions.
  */
-int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
-			 get_block_t get_block)
+vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+			 get_block_t get_block, int *err)
 {
 	struct page *page = vmf->page;
 	struct inode *inode = file_inode(vma->vm_file);
 	unsigned long end;
 	loff_t size;
-	int ret;
+	int err1;
 
 	lock_page(page);
 	size = i_size_read(inode);
 	if ((page->mapping != inode->i_mapping) ||
 	    (page_offset(page) > size)) {
 		/* We overload EFAULT to mean page got truncated */
-		ret = -EFAULT;
+		err1 = -EFAULT;
 		goto out_unlock;
 	}
 
@@ -2511,18 +2511,20 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 	else
 		end = PAGE_SIZE;
 
-	ret = __block_write_begin(page, 0, end, get_block);
-	if (!ret)
-		ret = block_commit_write(page, 0, end);
+	err1 = __block_write_begin(page, 0, end, get_block);
+	if (!err1)
+		err1 = block_commit_write(page, 0, end);
 
-	if (unlikely(ret < 0))
+	if (unlikely(err1 < 0))
 		goto out_unlock;
+	*err = err1;
 	set_page_dirty(page);
 	wait_for_stable_page(page);
 	return 0;
 out_unlock:
 	unlock_page(page);
-	return ret;
+	*err = err1;
+	return block_page_mkwrite_return(err1);
 }
 EXPORT_SYMBOL(block_page_mkwrite);
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 0f0edd1..8506b14 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2469,8 +2469,8 @@ int do_journal_get_write_access(handle_t *handle,
 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
 			     loff_t lstart, loff_t lend);
-extern int ext4_page_mkwrite(struct vm_fault *vmf);
-extern int ext4_filemap_fault(struct vm_fault *vmf);
+extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
+extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
 extern void ext4_da_update_reserve_space(struct inode *inode,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 82adee7..1062a8e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -6151,39 +6151,40 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
 	return !buffer_mapped(bh);
 }
 
-int ext4_page_mkwrite(struct vm_fault *vmf)
+vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct page *page = vmf->page;
 	loff_t size;
 	unsigned long len;
-	int ret;
+	vm_fault_t ret;
 	struct file *file = vma->vm_file;
 	struct inode *inode = file_inode(file);
 	struct address_space *mapping = inode->i_mapping;
 	handle_t *handle;
 	get_block_t *get_block;
-	int retries = 0;
+	int retries = 0, err;
 
 	sb_start_pagefault(inode->i_sb);
 	file_update_time(vma->vm_file);
 
 	down_read(&EXT4_I(inode)->i_mmap_sem);
 
-	ret = ext4_convert_inline_data(inode);
-	if (ret)
+	err = ext4_convert_inline_data(inode);
+	if (err)
 		goto out_ret;
 
+	err = 0;
 	/* Delalloc case is easy... */
 	if (test_opt(inode->i_sb, DELALLOC) &&
 	    !ext4_should_journal_data(inode) &&
 	    !ext4_nonda_switch(inode->i_sb)) {
 		do {
 			ret = block_page_mkwrite(vma, vmf,
-						   ext4_da_get_block_prep);
-		} while (ret == -ENOSPC &&
+					ext4_da_get_block_prep, &err);
+		} while (err == -ENOSPC &&
 		       ext4_should_retry_alloc(inode->i_sb, &retries));
-		goto out_ret;
+		goto out;
 	}
 
 	lock_page(page);
@@ -6226,36 +6227,37 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
 		ret = VM_FAULT_SIGBUS;
 		goto out;
 	}
-	ret = block_page_mkwrite(vma, vmf, get_block);
+	err = 0;
+	ret = block_page_mkwrite(vma, vmf, get_block, &err);
 	if (!ret && ext4_should_journal_data(inode)) {
 		if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
 			  PAGE_SIZE, NULL, do_journal_get_write_access)) {
 			unlock_page(page);
-			ret = VM_FAULT_SIGBUS;
 			ext4_journal_stop(handle);
 			goto out;
 		}
 		ext4_set_inode_state(inode, EXT4_STATE_JDATA);
 	}
 	ext4_journal_stop(handle);
-	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+	if (err == -ENOSPC &&
+		ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry_alloc;
 out_ret:
-	ret = block_page_mkwrite_return(ret);
+	ret = block_page_mkwrite_return(err);
 out:
 	up_read(&EXT4_I(inode)->i_mmap_sem);
 	sb_end_pagefault(inode->i_sb);
 	return ret;
 }
 
-int ext4_filemap_fault(struct vm_fault *vmf)
+vm_fault_t ext4_filemap_fault(struct vm_fault *vmf)
 {
 	struct inode *inode = file_inode(vmf->vma->vm_file);
-	int err;
+	vm_fault_t ret;
 
 	down_read(&EXT4_I(inode)->i_mmap_sem);
-	err = filemap_fault(vmf);
+	ret = filemap_fault(vmf);
 	up_read(&EXT4_I(inode)->i_mmap_sem);
 
-	return err;
+	return ret;
 }
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 7da0fac..58d2a81 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -57,7 +57,8 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
 	struct page *page = vmf->page;
 	struct inode *inode = file_inode(vma->vm_file);
 	struct nilfs_transaction_info ti;
-	int ret = 0;
+	vm_fault_t ret = VM_FAULT_LOCKED;
+	int err = 0;
 
 	if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
 		return VM_FAULT_SIGBUS; /* -ENOSPC */
@@ -67,7 +68,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
 	if (page->mapping != inode->i_mapping ||
 	    page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
 		unlock_page(page);
-		ret = -EFAULT;	/* make the VM retry the fault */
+		ret = VM_FAULT_NOPAGE;	/* make the VM retry the fault */
 		goto out;
 	}
 
@@ -99,13 +100,16 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
 	/*
 	 * fill hole blocks
 	 */
-	ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
+	err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
 	/* never returns -ENOMEM, but may return -ENOSPC */
-	if (unlikely(ret))
+	if (unlikely(err)) {
+		ret = block_page_mkwrite_return(err);
 		goto out;
+	}
 
+	err = 0;
 	file_update_time(vma->vm_file);
-	ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
+	ret = block_page_mkwrite(vma, vmf, nilfs_get_block, &err);
 	if (ret) {
 		nilfs_transaction_abort(inode->i_sb);
 		goto out;
@@ -117,7 +121,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
 	wait_for_stable_page(page);
  out:
 	sb_end_pagefault(inode->i_sb);
-	return block_page_mkwrite_return(ret);
+	return ret;
 }
 
 static const struct vm_operations_struct nilfs_file_vm_ops = {
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 96225a7..e212b13 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -14,6 +14,7 @@
 #include <linux/pagemap.h>
 #include <linux/wait.h>
 #include <linux/atomic.h>
+#include <linux/mm_types.h>
 
 #ifdef CONFIG_BLOCK
 
@@ -239,10 +240,10 @@ int cont_write_begin(struct file *, struct address_space *, loff_t,
 			get_block_t *, loff_t *);
 int generic_cont_expand_simple(struct inode *inode, loff_t size);
 int block_commit_write(struct page *page, unsigned from, unsigned to);
-int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
-				get_block_t get_block);
+vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+				get_block_t get_block, int *err);
 /* Convert errno to return value from ->page_mkwrite() call */
-static inline int block_page_mkwrite_return(int err)
+static inline vm_fault_t block_page_mkwrite_return(int err)
 {
 	if (err == 0)
 		return VM_FAULT_LOCKED;
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] fs: Convert return type int to vm_fault_t
  2018-08-28 19:25 [PATCH] fs: Convert return type int to vm_fault_t Souptick Joarder
@ 2018-08-30  7:56 ` Ryusuke Konishi
  2018-08-30 16:38   ` Souptick Joarder
  0 siblings, 1 reply; 3+ messages in thread
From: Ryusuke Konishi @ 2018-08-30  7:56 UTC (permalink / raw)
  To: Souptick Joarder
  Cc: willy, viro, tytso, adilger.kernel, darrick.wong, axboe,
	ebiggers, tglx, gregkh, kemi.wang, akpm, linux-fsdevel,
	linux-kernel, linux-ext4, linux-nilfs

Hi,

On Wed, 29 Aug 2018 00:55:28 +0530, Souptick Joarder wrote:
> Return type for fault handlers  in ext4 and nilfs are
> changed to use vm_fault_t.
> 
> Return type of block_page_mkwrite() is changed from
> int to vm_fault_t. The function signature of
> block_page_mkwrite() is changed to add one new parameter
> int *err. This will provide a way for caller functions
> to get error number along with VM_FAULT return value and
> use it further.
> 
> Return type of block_page_mkwrite_return() is also changed
> to use new vm_fault_t type.
> 
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> ---
>  fs/buffer.c                 | 20 +++++++++++---------
>  fs/ext4/ext4.h              |  4 ++--
>  fs/ext4/inode.c             | 34 ++++++++++++++++++----------------
>  fs/nilfs2/file.c            | 16 ++++++++++------
>  include/linux/buffer_head.h |  7 ++++---
>  5 files changed, 45 insertions(+), 36 deletions(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index ebf78ab..aacfc73 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -2487,21 +2487,21 @@ int block_commit_write(struct page *page, unsigned from, unsigned to)
>   * Direct callers of this function should protect against filesystem freezing
>   * using sb_start_pagefault() - sb_end_pagefault() functions.
>   */
> -int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> -			 get_block_t get_block)
> +vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> +			 get_block_t get_block, int *err)
>  {
>  	struct page *page = vmf->page;
>  	struct inode *inode = file_inode(vma->vm_file);
>  	unsigned long end;
>  	loff_t size;
> -	int ret;
> +	int err1;
>  
>  	lock_page(page);
>  	size = i_size_read(inode);
>  	if ((page->mapping != inode->i_mapping) ||
>  	    (page_offset(page) > size)) {
>  		/* We overload EFAULT to mean page got truncated */
> -		ret = -EFAULT;
> +		err1 = -EFAULT;
>  		goto out_unlock;
>  	}
>  
> @@ -2511,18 +2511,20 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
>  	else
>  		end = PAGE_SIZE;
>  
> -	ret = __block_write_begin(page, 0, end, get_block);
> -	if (!ret)
> -		ret = block_commit_write(page, 0, end);
> +	err1 = __block_write_begin(page, 0, end, get_block);
> +	if (!err1)
> +		err1 = block_commit_write(page, 0, end);
>  
> -	if (unlikely(ret < 0))
> +	if (unlikely(err1 < 0))
>  		goto out_unlock;
> +	*err = err1;
>  	set_page_dirty(page);
>  	wait_for_stable_page(page);
>  	return 0;
>  out_unlock:
>  	unlock_page(page);
> -	return ret;
> +	*err = err1;
> +	return block_page_mkwrite_return(err1);
>  }
>  EXPORT_SYMBOL(block_page_mkwrite);
>  
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 0f0edd1..8506b14 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2469,8 +2469,8 @@ int do_journal_get_write_access(handle_t *handle,
>  extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
>  extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
>  			     loff_t lstart, loff_t lend);
> -extern int ext4_page_mkwrite(struct vm_fault *vmf);
> -extern int ext4_filemap_fault(struct vm_fault *vmf);
> +extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
> +extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
>  extern qsize_t *ext4_get_reserved_space(struct inode *inode);
>  extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
>  extern void ext4_da_update_reserve_space(struct inode *inode,
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 82adee7..1062a8e 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -6151,39 +6151,40 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
>  	return !buffer_mapped(bh);
>  }
>  
> -int ext4_page_mkwrite(struct vm_fault *vmf)
> +vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
>  {
>  	struct vm_area_struct *vma = vmf->vma;
>  	struct page *page = vmf->page;
>  	loff_t size;
>  	unsigned long len;
> -	int ret;
> +	vm_fault_t ret;
>  	struct file *file = vma->vm_file;
>  	struct inode *inode = file_inode(file);
>  	struct address_space *mapping = inode->i_mapping;
>  	handle_t *handle;
>  	get_block_t *get_block;
> -	int retries = 0;
> +	int retries = 0, err;
>  
>  	sb_start_pagefault(inode->i_sb);
>  	file_update_time(vma->vm_file);
>  
>  	down_read(&EXT4_I(inode)->i_mmap_sem);
>  
> -	ret = ext4_convert_inline_data(inode);
> -	if (ret)
> +	err = ext4_convert_inline_data(inode);
> +	if (err)
>  		goto out_ret;
>  
> +	err = 0;
>  	/* Delalloc case is easy... */
>  	if (test_opt(inode->i_sb, DELALLOC) &&
>  	    !ext4_should_journal_data(inode) &&
>  	    !ext4_nonda_switch(inode->i_sb)) {
>  		do {
>  			ret = block_page_mkwrite(vma, vmf,
> -						   ext4_da_get_block_prep);
> -		} while (ret == -ENOSPC &&
> +					ext4_da_get_block_prep, &err);
> +		} while (err == -ENOSPC &&
>  		       ext4_should_retry_alloc(inode->i_sb, &retries));
> -		goto out_ret;
> +		goto out;
>  	}
>  
>  	lock_page(page);
> @@ -6226,36 +6227,37 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
>  		ret = VM_FAULT_SIGBUS;
>  		goto out;
>  	}
> -	ret = block_page_mkwrite(vma, vmf, get_block);
> +	err = 0;
> +	ret = block_page_mkwrite(vma, vmf, get_block, &err);
>  	if (!ret && ext4_should_journal_data(inode)) {
>  		if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
>  			  PAGE_SIZE, NULL, do_journal_get_write_access)) {
>  			unlock_page(page);
> -			ret = VM_FAULT_SIGBUS;
>  			ext4_journal_stop(handle);
>  			goto out;
>  		}
>  		ext4_set_inode_state(inode, EXT4_STATE_JDATA);
>  	}
>  	ext4_journal_stop(handle);
> -	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
> +	if (err == -ENOSPC &&
> +		ext4_should_retry_alloc(inode->i_sb, &retries))
>  		goto retry_alloc;
>  out_ret:
> -	ret = block_page_mkwrite_return(ret);
> +	ret = block_page_mkwrite_return(err);
>  out:
>  	up_read(&EXT4_I(inode)->i_mmap_sem);
>  	sb_end_pagefault(inode->i_sb);
>  	return ret;
>  }
>  
> -int ext4_filemap_fault(struct vm_fault *vmf)
> +vm_fault_t ext4_filemap_fault(struct vm_fault *vmf)
>  {
>  	struct inode *inode = file_inode(vmf->vma->vm_file);
> -	int err;
> +	vm_fault_t ret;
>  
>  	down_read(&EXT4_I(inode)->i_mmap_sem);
> -	err = filemap_fault(vmf);
> +	ret = filemap_fault(vmf);
>  	up_read(&EXT4_I(inode)->i_mmap_sem);
>  
> -	return err;
> +	return ret;
>  }
> diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
> index 7da0fac..58d2a81 100644
> --- a/fs/nilfs2/file.c
> +++ b/fs/nilfs2/file.c
> @@ -57,7 +57,8 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
>  	struct page *page = vmf->page;
>  	struct inode *inode = file_inode(vma->vm_file);
>  	struct nilfs_transaction_info ti;
> -	int ret = 0;
> +	vm_fault_t ret = VM_FAULT_LOCKED;
> +	int err = 0;
>  
>  	if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
>  		return VM_FAULT_SIGBUS; /* -ENOSPC */
> @@ -67,7 +68,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
>  	if (page->mapping != inode->i_mapping ||
>  	    page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
>  		unlock_page(page);
> -		ret = -EFAULT;	/* make the VM retry the fault */
> +		ret = VM_FAULT_NOPAGE;	/* make the VM retry the fault */
>  		goto out;
>  	}
>  
> @@ -99,13 +100,16 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
>  	/*
>  	 * fill hole blocks
>  	 */
> -	ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
> +	err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
>  	/* never returns -ENOMEM, but may return -ENOSPC */
> -	if (unlikely(ret))
> +	if (unlikely(err)) {
> +		ret = block_page_mkwrite_return(err);
>  		goto out;
> +	}
>  

> +	err = 0;

This initialization looks unnecessary.  "err" is always zero here.

Regards,
Ryusuke Konishi

>  	file_update_time(vma->vm_file);
> -	ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
> +	ret = block_page_mkwrite(vma, vmf, nilfs_get_block, &err);
>  	if (ret) {
>  		nilfs_transaction_abort(inode->i_sb);
>  		goto out;
> @@ -117,7 +121,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
>  	wait_for_stable_page(page);
>   out:
>  	sb_end_pagefault(inode->i_sb);
> -	return block_page_mkwrite_return(ret);
> +	return ret;
>  }
>  
>  static const struct vm_operations_struct nilfs_file_vm_ops = {
> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> index 96225a7..e212b13 100644
> --- a/include/linux/buffer_head.h
> +++ b/include/linux/buffer_head.h
> @@ -14,6 +14,7 @@
>  #include <linux/pagemap.h>
>  #include <linux/wait.h>
>  #include <linux/atomic.h>
> +#include <linux/mm_types.h>
>  
>  #ifdef CONFIG_BLOCK
>  
> @@ -239,10 +240,10 @@ int cont_write_begin(struct file *, struct address_space *, loff_t,
>  			get_block_t *, loff_t *);
>  int generic_cont_expand_simple(struct inode *inode, loff_t size);
>  int block_commit_write(struct page *page, unsigned from, unsigned to);
> -int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> -				get_block_t get_block);
> +vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> +				get_block_t get_block, int *err);
>  /* Convert errno to return value from ->page_mkwrite() call */
> -static inline int block_page_mkwrite_return(int err)
> +static inline vm_fault_t block_page_mkwrite_return(int err)
>  {
>  	if (err == 0)
>  		return VM_FAULT_LOCKED;
> -- 
> 1.9.1
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] fs: Convert return type int to vm_fault_t
  2018-08-30  7:56 ` Ryusuke Konishi
@ 2018-08-30 16:38   ` Souptick Joarder
  0 siblings, 0 replies; 3+ messages in thread
From: Souptick Joarder @ 2018-08-30 16:38 UTC (permalink / raw)
  To: Ryusuke Konishi
  Cc: Matthew Wilcox, Al Viro, Theodore Ts'o, adilger.kernel,
	Darrick J. Wong, Jens Axboe, Eric Biggers, Thomas Gleixner,
	Greg KH, kemi.wang, Andrew Morton, linux-fsdevel, linux-kernel,
	linux-ext4, linux-nilfs

On Thu, Aug 30, 2018 at 1:26 PM Ryusuke Konishi
<konishi.ryusuke@lab.ntt.co.jp> wrote:
>
> Hi,
>
> On Wed, 29 Aug 2018 00:55:28 +0530, Souptick Joarder wrote:
> > Return type for fault handlers  in ext4 and nilfs are
> > changed to use vm_fault_t.
> >
> > Return type of block_page_mkwrite() is changed from
> > int to vm_fault_t. The function signature of
> > block_page_mkwrite() is changed to add one new parameter
> > int *err. This will provide a way for caller functions
> > to get error number along with VM_FAULT return value and
> > use it further.
> >
> > Return type of block_page_mkwrite_return() is also changed
> > to use new vm_fault_t type.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > ---
> >  fs/buffer.c                 | 20 +++++++++++---------
> >  fs/ext4/ext4.h              |  4 ++--
> >  fs/ext4/inode.c             | 34 ++++++++++++++++++----------------
> >  fs/nilfs2/file.c            | 16 ++++++++++------
> >  include/linux/buffer_head.h |  7 ++++---
> >  5 files changed, 45 insertions(+), 36 deletions(-)
> >
> > diff --git a/fs/buffer.c b/fs/buffer.c
> > index ebf78ab..aacfc73 100644
> > --- a/fs/buffer.c
> > +++ b/fs/buffer.c
> > @@ -2487,21 +2487,21 @@ int block_commit_write(struct page *page, unsigned from, unsigned to)
> >   * Direct callers of this function should protect against filesystem freezing
> >   * using sb_start_pagefault() - sb_end_pagefault() functions.
> >   */
> > -int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> > -                      get_block_t get_block)
> > +vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> > +                      get_block_t get_block, int *err)
> >  {
> >       struct page *page = vmf->page;
> >       struct inode *inode = file_inode(vma->vm_file);
> >       unsigned long end;
> >       loff_t size;
> > -     int ret;
> > +     int err1;
> >
> >       lock_page(page);
> >       size = i_size_read(inode);
> >       if ((page->mapping != inode->i_mapping) ||
> >           (page_offset(page) > size)) {
> >               /* We overload EFAULT to mean page got truncated */
> > -             ret = -EFAULT;
> > +             err1 = -EFAULT;
> >               goto out_unlock;
> >       }
> >
> > @@ -2511,18 +2511,20 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> >       else
> >               end = PAGE_SIZE;
> >
> > -     ret = __block_write_begin(page, 0, end, get_block);
> > -     if (!ret)
> > -             ret = block_commit_write(page, 0, end);
> > +     err1 = __block_write_begin(page, 0, end, get_block);
> > +     if (!err1)
> > +             err1 = block_commit_write(page, 0, end);
> >
> > -     if (unlikely(ret < 0))
> > +     if (unlikely(err1 < 0))
> >               goto out_unlock;
> > +     *err = err1;
> >       set_page_dirty(page);
> >       wait_for_stable_page(page);
> >       return 0;
> >  out_unlock:
> >       unlock_page(page);
> > -     return ret;
> > +     *err = err1;
> > +     return block_page_mkwrite_return(err1);
> >  }
> >  EXPORT_SYMBOL(block_page_mkwrite);
> >
> > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> > index 0f0edd1..8506b14 100644
> > --- a/fs/ext4/ext4.h
> > +++ b/fs/ext4/ext4.h
> > @@ -2469,8 +2469,8 @@ int do_journal_get_write_access(handle_t *handle,
> >  extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
> >  extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
> >                            loff_t lstart, loff_t lend);
> > -extern int ext4_page_mkwrite(struct vm_fault *vmf);
> > -extern int ext4_filemap_fault(struct vm_fault *vmf);
> > +extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
> > +extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
> >  extern qsize_t *ext4_get_reserved_space(struct inode *inode);
> >  extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
> >  extern void ext4_da_update_reserve_space(struct inode *inode,
> > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> > index 82adee7..1062a8e 100644
> > --- a/fs/ext4/inode.c
> > +++ b/fs/ext4/inode.c
> > @@ -6151,39 +6151,40 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
> >       return !buffer_mapped(bh);
> >  }
> >
> > -int ext4_page_mkwrite(struct vm_fault *vmf)
> > +vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
> >  {
> >       struct vm_area_struct *vma = vmf->vma;
> >       struct page *page = vmf->page;
> >       loff_t size;
> >       unsigned long len;
> > -     int ret;
> > +     vm_fault_t ret;
> >       struct file *file = vma->vm_file;
> >       struct inode *inode = file_inode(file);
> >       struct address_space *mapping = inode->i_mapping;
> >       handle_t *handle;
> >       get_block_t *get_block;
> > -     int retries = 0;
> > +     int retries = 0, err;
> >
> >       sb_start_pagefault(inode->i_sb);
> >       file_update_time(vma->vm_file);
> >
> >       down_read(&EXT4_I(inode)->i_mmap_sem);
> >
> > -     ret = ext4_convert_inline_data(inode);
> > -     if (ret)
> > +     err = ext4_convert_inline_data(inode);
> > +     if (err)
> >               goto out_ret;
> >
> > +     err = 0;
> >       /* Delalloc case is easy... */
> >       if (test_opt(inode->i_sb, DELALLOC) &&
> >           !ext4_should_journal_data(inode) &&
> >           !ext4_nonda_switch(inode->i_sb)) {
> >               do {
> >                       ret = block_page_mkwrite(vma, vmf,
> > -                                                ext4_da_get_block_prep);
> > -             } while (ret == -ENOSPC &&
> > +                                     ext4_da_get_block_prep, &err);
> > +             } while (err == -ENOSPC &&
> >                      ext4_should_retry_alloc(inode->i_sb, &retries));
> > -             goto out_ret;
> > +             goto out;
> >       }
> >
> >       lock_page(page);
> > @@ -6226,36 +6227,37 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
> >               ret = VM_FAULT_SIGBUS;
> >               goto out;
> >       }
> > -     ret = block_page_mkwrite(vma, vmf, get_block);
> > +     err = 0;
> > +     ret = block_page_mkwrite(vma, vmf, get_block, &err);
> >       if (!ret && ext4_should_journal_data(inode)) {
> >               if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
> >                         PAGE_SIZE, NULL, do_journal_get_write_access)) {
> >                       unlock_page(page);
> > -                     ret = VM_FAULT_SIGBUS;
> >                       ext4_journal_stop(handle);
> >                       goto out;
> >               }
> >               ext4_set_inode_state(inode, EXT4_STATE_JDATA);
> >       }
> >       ext4_journal_stop(handle);
> > -     if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
> > +     if (err == -ENOSPC &&
> > +             ext4_should_retry_alloc(inode->i_sb, &retries))
> >               goto retry_alloc;
> >  out_ret:
> > -     ret = block_page_mkwrite_return(ret);
> > +     ret = block_page_mkwrite_return(err);
> >  out:
> >       up_read(&EXT4_I(inode)->i_mmap_sem);
> >       sb_end_pagefault(inode->i_sb);
> >       return ret;
> >  }
> >
> > -int ext4_filemap_fault(struct vm_fault *vmf)
> > +vm_fault_t ext4_filemap_fault(struct vm_fault *vmf)
> >  {
> >       struct inode *inode = file_inode(vmf->vma->vm_file);
> > -     int err;
> > +     vm_fault_t ret;
> >
> >       down_read(&EXT4_I(inode)->i_mmap_sem);
> > -     err = filemap_fault(vmf);
> > +     ret = filemap_fault(vmf);
> >       up_read(&EXT4_I(inode)->i_mmap_sem);
> >
> > -     return err;
> > +     return ret;
> >  }
> > diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
> > index 7da0fac..58d2a81 100644
> > --- a/fs/nilfs2/file.c
> > +++ b/fs/nilfs2/file.c
> > @@ -57,7 +57,8 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
> >       struct page *page = vmf->page;
> >       struct inode *inode = file_inode(vma->vm_file);
> >       struct nilfs_transaction_info ti;
> > -     int ret = 0;
> > +     vm_fault_t ret = VM_FAULT_LOCKED;
> > +     int err = 0;
> >
> >       if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
> >               return VM_FAULT_SIGBUS; /* -ENOSPC */
> > @@ -67,7 +68,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
> >       if (page->mapping != inode->i_mapping ||
> >           page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
> >               unlock_page(page);
> > -             ret = -EFAULT;  /* make the VM retry the fault */
> > +             ret = VM_FAULT_NOPAGE;  /* make the VM retry the fault */
> >               goto out;
> >       }
> >
> > @@ -99,13 +100,16 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
> >       /*
> >        * fill hole blocks
> >        */
> > -     ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
> > +     err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
> >       /* never returns -ENOMEM, but may return -ENOSPC */
> > -     if (unlikely(ret))
> > +     if (unlikely(err)) {
> > +             ret = block_page_mkwrite_return(err);
> >               goto out;
> > +     }
> >
>
> > +     err = 0;
>
> This initialization looks unnecessary.  "err" is always zero here.

Agree.
>
> > +     ret = block_page_mkwrite(vma, vmf, nilfs_get_block, &err);
> >       if (ret) {
> >               nilfs_transaction_abort(inode->i_sb);
> >               goto out;
> > @@ -117,7 +121,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
> >       wait_for_stable_page(page);
> >   out:
> >       sb_end_pagefault(inode->i_sb);
> > -     return block_page_mkwrite_return(ret);
> > +     return ret;
> >  }
> >
> >  static const struct vm_operations_struct nilfs_file_vm_ops = {
> > diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> > index 96225a7..e212b13 100644
> > --- a/include/linux/buffer_head.h
> > +++ b/include/linux/buffer_head.h
> > @@ -14,6 +14,7 @@
> >  #include <linux/pagemap.h>
> >  #include <linux/wait.h>
> >  #include <linux/atomic.h>
> > +#include <linux/mm_types.h>
> >
> >  #ifdef CONFIG_BLOCK
> >
> > @@ -239,10 +240,10 @@ int cont_write_begin(struct file *, struct address_space *, loff_t,
> >                       get_block_t *, loff_t *);
> >  int generic_cont_expand_simple(struct inode *inode, loff_t size);
> >  int block_commit_write(struct page *page, unsigned from, unsigned to);
> > -int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> > -                             get_block_t get_block);
> > +vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> > +                             get_block_t get_block, int *err);
> >  /* Convert errno to return value from ->page_mkwrite() call */
> > -static inline int block_page_mkwrite_return(int err)
> > +static inline vm_fault_t block_page_mkwrite_return(int err)
> >  {
> >       if (err == 0)
> >               return VM_FAULT_LOCKED;
> > --
> > 1.9.1
> >

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-08-30 20:38 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-28 19:25 [PATCH] fs: Convert return type int to vm_fault_t Souptick Joarder
2018-08-30  7:56 ` Ryusuke Konishi
2018-08-30 16:38   ` Souptick Joarder

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