2017-11-01 15:36:46

by Jan Kara

[permalink] [raw]
Subject: [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()

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 <[email protected]>
---
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


2017-11-14 02:19:13

by Darrick J. Wong

[permalink] [raw]
Subject: Re: [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()

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 <[email protected]>

Looks ok,
Reviewed-by: Darrick J. Wong <[email protected]>

> ---
> 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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