[17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()

Message ID 20171101153648.30166-18-jack@suse.cz
State New
Headers show
Series
  • dax, ext4, xfs: Synchronous page faults
Related show

Commit Message

Jan Kara Nov. 1, 2017, 3:36 p.m.
xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
It will also need to handle flushing for synchronous page faults. So
just make that function use __xfs_filemap_fault().

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_file.c  | 29 ++++-------------------------
 fs/xfs/xfs_trace.h |  2 --
 2 files changed, 4 insertions(+), 27 deletions(-)

Comments

Darrick J. Wong Nov. 14, 2017, 2:19 a.m. | #1
On Wed, Nov 01, 2017 at 04:36:46PM +0100, Jan Kara wrote:
> xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
> It will also need to handle flushing for synchronous page faults. So
> just make that function use __xfs_filemap_fault().
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

> ---
>  fs/xfs/xfs_file.c  | 29 ++++-------------------------
>  fs/xfs/xfs_trace.h |  2 --
>  2 files changed, 4 insertions(+), 27 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 7c6b8def6eed..4496b45678de 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
>  }
>  
>  /*
> - * pfn_mkwrite was originally inteneded to ensure we capture time stamp
> - * updates on write faults. In reality, it's need to serialise against
> - * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
> - * to ensure we serialise the fault barrier in place.
> + * pfn_mkwrite was originally intended to ensure we capture time stamp updates
> + * on write faults. In reality, it needs to serialise against truncate and
> + * prepare memory for writing so handle is as standard write fault.
>   */
>  static int
>  xfs_filemap_pfn_mkwrite(
>  	struct vm_fault		*vmf)
>  {
>  
> -	struct inode		*inode = file_inode(vmf->vma->vm_file);
> -	struct xfs_inode	*ip = XFS_I(inode);
> -	int			ret = VM_FAULT_NOPAGE;
> -	loff_t			size;
> -
> -	trace_xfs_filemap_pfn_mkwrite(ip);
> -
> -	sb_start_pagefault(inode->i_sb);
> -	file_update_time(vmf->vma->vm_file);
> -
> -	/* check if the faulting page hasn't raced with truncate */
> -	xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
> -	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
> -	if (vmf->pgoff >= size)
> -		ret = VM_FAULT_SIGBUS;
> -	else if (IS_DAX(inode))
> -		ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
> -	xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
> -	sb_end_pagefault(inode->i_sb);
> -	return ret;
> -
> +	return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
>  }
>  
>  static const struct vm_operations_struct xfs_file_vm_ops = {
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index bb5514688d47..6333ad09e0f3 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
>  DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
>  DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
>  
> -DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
> -
>  TRACE_EVENT(xfs_filemap_fault,
>  	TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
>  		 bool write_fault),
> -- 
> 2.12.3
> 
> --
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Patch

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7c6b8def6eed..4496b45678de 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1085,37 +1085,16 @@  xfs_filemap_page_mkwrite(
 }
 
 /*
- * pfn_mkwrite was originally inteneded to ensure we capture time stamp
- * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
- * to ensure we serialise the fault barrier in place.
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
  */
 static int
 xfs_filemap_pfn_mkwrite(
 	struct vm_fault		*vmf)
 {
 
-	struct inode		*inode = file_inode(vmf->vma->vm_file);
-	struct xfs_inode	*ip = XFS_I(inode);
-	int			ret = VM_FAULT_NOPAGE;
-	loff_t			size;
-
-	trace_xfs_filemap_pfn_mkwrite(ip);
-
-	sb_start_pagefault(inode->i_sb);
-	file_update_time(vmf->vma->vm_file);
-
-	/* check if the faulting page hasn't raced with truncate */
-	xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
-	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	if (vmf->pgoff >= size)
-		ret = VM_FAULT_SIGBUS;
-	else if (IS_DAX(inode))
-		ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
-	xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
-	sb_end_pagefault(inode->i_sb);
-	return ret;
-
+	return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
 }
 
 static const struct vm_operations_struct xfs_file_vm_ops = {
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb5514688d47..6333ad09e0f3 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -688,8 +688,6 @@  DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
 DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
 DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
 
-DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
-
 TRACE_EVENT(xfs_filemap_fault,
 	TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
 		 bool write_fault),