2011-06-15 16:31:25

by Fred Isaman

[permalink] [raw]
Subject: [PATCH 1/1] nfs4.1: prevent race that allowed use of freed layout in _pnfs_return_layout

mark_matching_lsegs_invalid could put the last ref to the layout, so
the get_layout_hdr needs to be called first.

Signed-off-by: Fred Isaman <[email protected]>
---
fs/nfs/pnfs.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index d25f66d..f99f068 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -646,10 +646,10 @@ _pnfs_return_layout(struct inode *ino)
return status;
}
stateid = nfsi->layout->plh_stateid;
- mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
- lo->plh_block_lgets++;
/* Reference matched in nfs4_layoutreturn_release */
get_layout_hdr(lo);
+ mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
+ lo->plh_block_lgets++;
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&tmp_list);

--
1.7.2.1