[PATCH 4.2 30/54] nfsd/blocklayout: accept any minlength

Greg Kroah-Hartman
2015-10-23T18:26:45Z

From: Christoph Hellwig <hch@lst.de>

commit 8c3ad9cb7343dc5f61b8cf3cdbe1016c5e7c2c8b upstream.

Recent Linux clients have started to send GETLAYOUT requests with
minlength less than blocksize.

Servers aren't really allowed to impose this kind of restriction on
layouts; see RFC 5661 section 18.43.3 for details.

This has been observed to cause indefinite hangs on fsx runs on some
clients.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfsd/blocklayout.c | 8 --------
1 file changed, 8 deletions(-)

--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -56,14 +56,6 @@ nfsd4_block_proc_layoutget(struct inode
u32 device_generation = 0;
int error;

- /*
- * We do not attempt to support I/O smaller than the fs block size,
- * or not aligned to it.
- */
- if (args->lg_minlength < block_size) {
- dprintk("pnfsd: I/O too small\n");
- goto out_layoutunavailable;
- }
if (seg->offset & (block_size - 1)) {
dprintk("pnfsd: I/O misaligned\n");
goto out_layoutunavailable;