Merge branch 'for-4.18/dax' into libnvdimm-for-next
[sfrench/cifs-2.6.git] / fs / xfs / xfs_file.c
index e70fb8cceceaa5d2333573e49460beba75629815..19b0c3e0e232203ffb2c8f7c60d640424542b2b7 100644 (file)
@@ -312,7 +312,7 @@ restart:
        if (error <= 0)
                return error;
 
-       error = xfs_break_layouts(inode, iolock);
+       error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
        if (error)
                return error;
 
@@ -718,6 +718,69 @@ buffered:
        return ret;
 }
 
+static void
+xfs_wait_dax_page(
+       struct inode            *inode,
+       bool                    *did_unlock)
+{
+       struct xfs_inode        *ip = XFS_I(inode);
+
+       *did_unlock = true;
+       xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
+       schedule();
+       xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+}
+
+static int
+xfs_break_dax_layouts(
+       struct inode            *inode,
+       uint                    iolock,
+       bool                    *did_unlock)
+{
+       struct page             *page;
+
+       ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL));
+
+       page = dax_layout_busy_page(inode->i_mapping);
+       if (!page)
+               return 0;
+
+       return ___wait_var_event(&page->_refcount,
+                       atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
+                       0, 0, xfs_wait_dax_page(inode, did_unlock));
+}
+
+int
+xfs_break_layouts(
+       struct inode            *inode,
+       uint                    *iolock,
+       enum layout_break_reason reason)
+{
+       bool                    retry;
+       int                     error;
+
+       ASSERT(xfs_isilocked(XFS_I(inode), XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
+
+       do {
+               retry = false;
+               switch (reason) {
+               case BREAK_UNMAP:
+                       error = xfs_break_dax_layouts(inode, *iolock, &retry);
+                       if (error || retry)
+                               break;
+                       /* fall through */
+               case BREAK_WRITE:
+                       error = xfs_break_leased_layouts(inode, iolock, &retry);
+                       break;
+               default:
+                       WARN_ON_ONCE(1);
+                       error = -EINVAL;
+               }
+       } while (error == 0 && retry);
+
+       return error;
+}
+
 #define        XFS_FALLOC_FL_SUPPORTED                                         \
                (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |           \
                 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |      \
@@ -734,7 +797,7 @@ xfs_file_fallocate(
        struct xfs_inode        *ip = XFS_I(inode);
        long                    error;
        enum xfs_prealloc_flags flags = 0;
-       uint                    iolock = XFS_IOLOCK_EXCL;
+       uint                    iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
        loff_t                  new_size = 0;
        bool                    do_file_insert = false;
 
@@ -744,13 +807,10 @@ xfs_file_fallocate(
                return -EOPNOTSUPP;
 
        xfs_ilock(ip, iolock);
-       error = xfs_break_layouts(inode, &iolock);
+       error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
        if (error)
                goto out_unlock;
 
-       xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
-       iolock |= XFS_MMAPLOCK_EXCL;
-
        if (mode & FALLOC_FL_PUNCH_HOLE) {
                error = xfs_free_file_space(ip, offset, len);
                if (error)