xfs: refactor __xfs_filemap_fault

Split the write fault and DAX fault handling into separate helpers
so that the main fault handler is easier to follow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 8aab2f66fe016ffd8f52c080e90df784a251c607..32a2cd6ec82e0c7a46e48a47b00f20ec4a4fa0f1 100644 (file)
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1252,7 +1252,7 @@ xfs_file_llseek(
 }
 
 static inline vm_fault_t
-xfs_dax_fault(
+xfs_dax_fault_locked(
        struct vm_fault         *vmf,
        unsigned int            order,
        bool                    write_fault)
@@ -1273,6 +1273,45 @@ xfs_dax_fault(
        return ret;
 }
 
+static vm_fault_t
+xfs_dax_read_fault(
+       struct vm_fault         *vmf,
+       unsigned int            order)
+{
+       struct xfs_inode        *ip = XFS_I(file_inode(vmf->vma->vm_file));
+       unsigned int            lock_mode;
+       vm_fault_t              ret;
+
+       lock_mode = xfs_ilock_for_write_fault(ip);
+       ret = xfs_dax_fault_locked(vmf, order, false);
+       xfs_iunlock(ip, lock_mode);
+
+       return ret;
+}
+
+static vm_fault_t
+xfs_write_fault(
+       struct vm_fault         *vmf,
+       unsigned int            order)
+{
+       struct inode            *inode = file_inode(vmf->vma->vm_file);
+       unsigned int            lock_mode;
+       vm_fault_t              ret;
+
+       sb_start_pagefault(inode->i_sb);
+       file_update_time(vmf->vma->vm_file);
+
+       lock_mode = xfs_ilock_for_write_fault(XFS_I(inode));
+       if (IS_DAX(inode))
+               ret = xfs_dax_fault_locked(vmf, order, true);
+       else
+               ret = iomap_page_mkwrite(vmf, &xfs_page_mkwrite_iomap_ops);
+       xfs_iunlock(XFS_I(inode), lock_mode);
+
+       sb_end_pagefault(inode->i_sb);
+       return ret;
+}
+
 /*
  * Locking for serialisation of IO during page faults. This results in a lock
  * ordering of:
@@ -1290,34 +1329,14 @@ __xfs_filemap_fault(
        bool                    write_fault)
 {
        struct inode            *inode = file_inode(vmf->vma->vm_file);
-       struct xfs_inode        *ip = XFS_I(inode);
-       vm_fault_t              ret;
-       unsigned int            lock_mode = 0;
-
-       trace_xfs_filemap_fault(ip, order, write_fault);
 
-       if (write_fault) {
-               sb_start_pagefault(inode->i_sb);
-               file_update_time(vmf->vma->vm_file);
-       }
-
-       if (IS_DAX(inode) || write_fault)
-               lock_mode = xfs_ilock_for_write_fault(XFS_I(inode));
-
-       if (IS_DAX(inode)) {
-               ret = xfs_dax_fault(vmf, order, write_fault);
-       } else if (write_fault) {
-               ret = iomap_page_mkwrite(vmf, &xfs_page_mkwrite_iomap_ops);
-       } else {
-               ret = filemap_fault(vmf);
-       }
-
-       if (lock_mode)
-               xfs_iunlock(XFS_I(inode), lock_mode);
+       trace_xfs_filemap_fault(XFS_I(inode), order, write_fault);
 
        if (write_fault)
-               sb_end_pagefault(inode->i_sb);
-       return ret;
+               return xfs_write_fault(vmf, order);
+       if (IS_DAX(inode))
+               return xfs_dax_read_fault(vmf, order);
+       return filemap_fault(vmf);
 }
 
 static inline bool