xfs: consider shutdown in bmapbt cursor delete assert

commit 5fd4bdffa015359b962872ddc1a2c22d2d63c82a upstream.

[ Slightly modify fs/xfs/libxfs/xfs_btree.c to resolve merge conflicts ]

The assert in xfs_btree_del_cursor() checks that the bmapbt block
allocation field has been handled correctly before the cursor is
freed. This field is used for accurate calculation of indirect block
reservation requirements (for delayed allocations), for example.
generic/019 reproduces a scenario where this assert fails because
the filesystem has shutdown while in the middle of a bmbt record
insertion. This occurs after a bmbt block has been allocated via the
cursor but before the higher level bmap function (i.e.
xfs_bmap_add_extent_hole_real()) completes and resets the field.

Update the assert to accommodate the transient state if the
filesystem has shutdown. While here, clean up the indentation and
comments in the function.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 8c43cac15832b28724c0f2014230dc7408c6e8c3..121251651feaddeffce8ea9e0daf9f5a2e07c053 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -354,20 +354,17 @@ xfs_btree_free_block(
  */
 void
 xfs_btree_del_cursor(
-       xfs_btree_cur_t *cur,           /* btree cursor */
-       int             error)          /* del because of error */
+       struct xfs_btree_cur    *cur,           /* btree cursor */
+       int                     error)          /* del because of error */
 {
-       int             i;              /* btree level */
+       int                     i;              /* btree level */
 
        /*
-        * Clear the buffer pointers, and release the buffers.
-        * If we're doing this in the face of an error, we
-        * need to make sure to inspect all of the entries
-        * in the bc_bufs array for buffers to be unlocked.
-        * This is because some of the btree code works from
-        * level n down to 0, and if we get an error along
-        * the way we won't have initialized all the entries
-        * down to 0.
+        * Clear the buffer pointers and release the buffers. If we're doing
+        * this because of an error, inspect all of the entries in the bc_bufs
+        * array for buffers to be unlocked. This is because some of the btree
+        * code works from level n down to 0, and if we get an error along the
+        * way we won't have initialized all the entries down to 0.
         */
        for (i = 0; i < cur->bc_nlevels; i++) {
                if (cur->bc_bufs[i])
@@ -375,15 +372,10 @@ xfs_btree_del_cursor(
                else if (!error)
                        break;
        }
-       /*
-        * Can't free a bmap cursor without having dealt with the
-        * allocated indirect blocks' accounting.
-        */
+
        ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
-              cur->bc_private.b.allocated == 0);
-       /*
-        * Free the cursor.
-        */
+              cur->bc_private.b.allocated == 0 ||
+              XFS_FORCED_SHUTDOWN(cur->bc_mp));
        kmem_zone_free(xfs_btree_cur_zone, cur);
 }