xfs: consolidate the various page fault handlers
Add a new __xfs_filemap_fault helper that implements all four page fault
callouts, and make these methods themselves small stubs that set the
correct write_fault flag, and exit early for the non-DAX case for the
hugepage related ones.
Also remove the extra size checking in the pfn_fault path, which is now
handled in the core DAX code.
Life would be so much simpler if we only had one method for all this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 8b0181c..0debbc7 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1011,97 +1011,69 @@
* page_lock (MM)
* i_lock (XFS - extent map serialisation)
*/
-
-/*
- * mmap()d file has taken write protection fault and is being made writable. We
- * can set the page state up correctly for a writable page, which means we can
- * do correct delalloc accounting (ENOSPC checking!) and unwritten extent
- * mapping.
- */
-STATIC int
-xfs_filemap_page_mkwrite(
- struct vm_fault *vmf)
-{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- int ret;
-
- trace_xfs_filemap_page_mkwrite(XFS_I(inode));
-
- sb_start_pagefault(inode->i_sb);
- file_update_time(vmf->vma->vm_file);
- xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
-
- if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
- } else {
- ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
- }
-
- xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
-
- return ret;
-}
-
-STATIC int
-xfs_filemap_fault(
- struct vm_fault *vmf)
-{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- int ret;
-
- trace_xfs_filemap_fault(XFS_I(inode));
-
- /* DAX can shortcut the normal fault path on write faults! */
- if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(inode))
- return xfs_filemap_page_mkwrite(vmf);
-
- xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
- else
- ret = filemap_fault(vmf);
- xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
-
- return ret;
-}
-
-/*
- * Similar to xfs_filemap_fault(), the DAX fault path can call into here on
- * both read and write faults. Hence we need to handle both cases. There is no
- * ->huge_mkwrite callout for huge pages, so we have a single function here to
- * handle both cases here. @flags carries the information on the type of fault
- * occuring.
- */
-STATIC int
-xfs_filemap_huge_fault(
+static int
+__xfs_filemap_fault(
struct vm_fault *vmf,
- enum page_entry_size pe_size)
+ enum page_entry_size pe_size,
+ bool write_fault)
{
struct inode *inode = file_inode(vmf->vma->vm_file);
struct xfs_inode *ip = XFS_I(inode);
int ret;
- if (!IS_DAX(inode))
- return VM_FAULT_FALLBACK;
+ trace_xfs_filemap_fault(ip, pe_size, write_fault);
- trace_xfs_filemap_huge_fault(ip);
-
- if (vmf->flags & FAULT_FLAG_WRITE) {
+ if (write_fault) {
sb_start_pagefault(inode->i_sb);
file_update_time(vmf->vma->vm_file);
}
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ if (IS_DAX(inode)) {
+ ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ } else {
+ if (write_fault)
+ ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
+ else
+ ret = filemap_fault(vmf);
+ }
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (write_fault)
sb_end_pagefault(inode->i_sb);
-
return ret;
}
+static int
+xfs_filemap_fault(
+ struct vm_fault *vmf)
+{
+ /* DAX can shortcut the normal fault path on write faults! */
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE,
+ IS_DAX(file_inode(vmf->vma->vm_file)) &&
+ (vmf->flags & FAULT_FLAG_WRITE));
+}
+
+static int
+xfs_filemap_huge_fault(
+ struct vm_fault *vmf,
+ enum page_entry_size pe_size)
+{
+ if (!IS_DAX(file_inode(vmf->vma->vm_file)))
+ return VM_FAULT_FALLBACK;
+
+ /* DAX can shortcut the normal fault path on write faults! */
+ return __xfs_filemap_fault(vmf, pe_size,
+ (vmf->flags & FAULT_FLAG_WRITE));
+}
+
+static int
+xfs_filemap_page_mkwrite(
+ struct vm_fault *vmf)
+{
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
+}
+
/*
* pfn_mkwrite was originally inteneded to ensure we capture time stamp
* updates on write faults. In reality, it's need to serialise against