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authorDave Chinner <dchinner@redhat.com>2015-11-02 20:37:02 -0500
committerDave Chinner <david@fromorbit.com>2015-11-02 20:37:02 -0500
commit3af49285854df66260a263198cc15abb07b95287 (patch)
tree36cf3d76bccae803a58886953be4709454a16838
parent01a155e6cf7db1a8ff2aa73162d7d9ec05ad298f (diff)
xfs: add ->pfn_mkwrite support for DAX
->pfn_mkwrite support is needed so that when a page with allocated backing store takes a write fault we can check that the fault has not raced with a truncate and is pointing to a region beyond the current end of file. This also allows us to update the timestamp on the inode, too, which fixes a generic/080 failure. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
-rw-r--r--fs/xfs/xfs_file.c35
-rw-r--r--fs/xfs/xfs_trace.h1
2 files changed, 36 insertions, 0 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 9c8eef7c57b4..f429662d7d42 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1572,11 +1572,46 @@ xfs_filemap_pmd_fault(
1572 return ret; 1572 return ret;
1573} 1573}
1574 1574
1575/*
1576 * pfn_mkwrite was originally inteneded to ensure we capture time stamp
1577 * updates on write faults. In reality, it's need to serialise against
1578 * truncate similar to page_mkwrite. Hence we open-code dax_pfn_mkwrite()
1579 * here and cycle the XFS_MMAPLOCK_SHARED to ensure we serialise the fault
1580 * barrier in place.
1581 */
1582static int
1583xfs_filemap_pfn_mkwrite(
1584 struct vm_area_struct *vma,
1585 struct vm_fault *vmf)
1586{
1587
1588 struct inode *inode = file_inode(vma->vm_file);
1589 struct xfs_inode *ip = XFS_I(inode);
1590 int ret = VM_FAULT_NOPAGE;
1591 loff_t size;
1592
1593 trace_xfs_filemap_pfn_mkwrite(ip);
1594
1595 sb_start_pagefault(inode->i_sb);
1596 file_update_time(vma->vm_file);
1597
1598 /* check if the faulting page hasn't raced with truncate */
1599 xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
1600 size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
1601 if (vmf->pgoff >= size)
1602 ret = VM_FAULT_SIGBUS;
1603 xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
1604 sb_end_pagefault(inode->i_sb);
1605 return ret;
1606
1607}
1608
1575static const struct vm_operations_struct xfs_file_vm_ops = { 1609static const struct vm_operations_struct xfs_file_vm_ops = {
1576 .fault = xfs_filemap_fault, 1610 .fault = xfs_filemap_fault,
1577 .pmd_fault = xfs_filemap_pmd_fault, 1611 .pmd_fault = xfs_filemap_pmd_fault,
1578 .map_pages = filemap_map_pages, 1612 .map_pages = filemap_map_pages,
1579 .page_mkwrite = xfs_filemap_page_mkwrite, 1613 .page_mkwrite = xfs_filemap_page_mkwrite,
1614 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1580}; 1615};
1581 1616
1582STATIC int 1617STATIC int
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 5ed36b1e04c1..c53beda675d6 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -689,6 +689,7 @@ DEFINE_INODE_EVENT(xfs_inode_free_eofblocks_invalid);
689DEFINE_INODE_EVENT(xfs_filemap_fault); 689DEFINE_INODE_EVENT(xfs_filemap_fault);
690DEFINE_INODE_EVENT(xfs_filemap_pmd_fault); 690DEFINE_INODE_EVENT(xfs_filemap_pmd_fault);
691DEFINE_INODE_EVENT(xfs_filemap_page_mkwrite); 691DEFINE_INODE_EVENT(xfs_filemap_page_mkwrite);
692DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
692 693
693DECLARE_EVENT_CLASS(xfs_iref_class, 694DECLARE_EVENT_CLASS(xfs_iref_class,
694 TP_PROTO(struct xfs_inode *ip, unsigned long caller_ip), 695 TP_PROTO(struct xfs_inode *ip, unsigned long caller_ip),