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Commit 02917bef authored by Trond Myklebust's avatar Trond Myklebust Committed by Sasha Levin
Browse files

pNFS/flexfiles: Fix list corruption if the mirror count changes 



commit 8b04013737341442ed914b336cde866b902664ae upstream.

If the mirror count changes in the new layout we pick up inside
ff_layout_pg_init_write(), then we can end up adding the
request to the wrong mirror and corrupting the mirror->pg_list.

Fixes: d600ad1f ("NFS41: pop some layoutget errors to application")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7b99577f

fs/nfs/flexfilelayout/flexfilelayout.c

+7 −4
Original line number Diff line number Diff line
@@ -984,9 +984,8 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
		goto out_mds;



	/* Use a direct mapping of ds_idx to pgio mirror_idx */

	if (WARN_ON_ONCE(pgio->pg_mirror_count !=

	    FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))

		goto out_mds;

	if (pgio->pg_mirror_count != FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg))

		goto out_eagain;



	for (i = 0; i < pgio->pg_mirror_count; i++) {

		mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
@@ -1008,7 +1007,10 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
			(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))

		pgio->pg_maxretrans = io_maxretrans;

	return;



out_eagain:

	pnfs_generic_pg_cleanup(pgio);

	pgio->pg_error = -EAGAIN;

	return;

out_mds:

	trace_pnfs_mds_fallback_pg_init_write(pgio->pg_inode,

			0, NFS4_MAX_UINT64, IOMODE_RW,
@@ -1018,6 +1020,7 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
	pgio->pg_lseg = NULL;

	pgio->pg_maxretrans = 0;

	nfs_pageio_reset_write_mds(pgio);

	pgio->pg_error = -EAGAIN;

}



static unsigned int