Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3dc14735 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

pNFS/flexfiles: Fix an Oopsable condition when connection to the DS fails 



If the attempt to connect to a DS fails inside ff_layout_pg_init_read or
ff_layout_pg_init_write, then we currently end up clearing the layout
segment carried by the struct nfs_pageio_descriptor, causing an Oops
when we later call into ff_layout_read_pagelist/ff_layout_write_pagelist.

The fix is to ensure we return the layout and then retry.

Fixes: 446ca219 ("pNFS/flexfiles: When initing reads or writes, we...")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent d138027a

fs/nfs/flexfilelayout/flexfilelayout.c

+18 −19
Original line number Diff line number Diff line
@@ -806,11 +806,14 @@ ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg, 
{

	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);

	struct nfs4_pnfs_ds *ds;

	bool fail_return = false;

	int idx;



	/* mirrors are sorted by efficiency */

	for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {

		ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);

		if (idx+1 == fls->mirror_array_cnt)

			fail_return = true;

		ds = nfs4_ff_layout_prepare_ds(lseg, idx, fail_return);

		if (ds) {

			*best_idx = idx;

			return ds;
@@ -859,6 +862,7 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, 
	struct nfs4_pnfs_ds *ds;

	int ds_idx;



retry:

	/* Use full layout for now */

	if (!pgio->pg_lseg)

		ff_layout_pg_get_read(pgio, req, false);
@@ -871,10 +875,13 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, 


	ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);

	if (!ds) {

		if (ff_layout_no_fallback_to_mds(pgio->pg_lseg))

			goto out_pnfs;

		else

		if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))

			goto out_mds;

		pnfs_put_lseg(pgio->pg_lseg);

		pgio->pg_lseg = NULL;

		/* Sleep for 1 second before retrying */

		ssleep(1);

		goto retry;

	}



	mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
@@ -890,12 +897,6 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, 
	pnfs_put_lseg(pgio->pg_lseg);

	pgio->pg_lseg = NULL;

	nfs_pageio_reset_read_mds(pgio);

	return;



out_pnfs:

	pnfs_set_lo_fail(pgio->pg_lseg);

	pnfs_put_lseg(pgio->pg_lseg);

	pgio->pg_lseg = NULL;

}



static void
@@ -909,6 +910,7 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
	int i;

	int status;



retry:

	if (!pgio->pg_lseg) {

		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,

						   req->wb_context,
@@ -940,10 +942,13 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
	for (i = 0; i < pgio->pg_mirror_count; i++) {

		ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);

		if (!ds) {

			if (ff_layout_no_fallback_to_mds(pgio->pg_lseg))

				goto out_pnfs;

			else

			if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))

				goto out_mds;

			pnfs_put_lseg(pgio->pg_lseg);

			pgio->pg_lseg = NULL;

			/* Sleep for 1 second before retrying */

			ssleep(1);

			goto retry;

		}

		pgm = &pgio->pg_mirrors[i];

		mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
@@ -956,12 +961,6 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
	pnfs_put_lseg(pgio->pg_lseg);

	pgio->pg_lseg = NULL;

	nfs_pageio_reset_write_mds(pgio);

	return;



out_pnfs:

	pnfs_set_lo_fail(pgio->pg_lseg);

	pnfs_put_lseg(pgio->pg_lseg);

	pgio->pg_lseg = NULL;

}



static unsigned int

fs/nfs/flexfilelayout/flexfilelayoutdev.c

+10 −9
Original line number Diff line number Diff line
@@ -379,7 +379,7 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx, 


	devid = &mirror->mirror_ds->id_node;

	if (ff_layout_test_devid_unavailable(devid))

		goto out;

		goto out_fail;



	ds = mirror->mirror_ds->ds;

	/* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */
@@ -405,15 +405,16 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx, 
			mirror->mirror_ds->ds_versions[0].rsize = max_payload;

		if (mirror->mirror_ds->ds_versions[0].wsize > max_payload)

			mirror->mirror_ds->ds_versions[0].wsize = max_payload;

	} else {

		goto out;

	}

	ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),

				 mirror, lseg->pls_range.offset,

				 lseg->pls_range.length, NFS4ERR_NXIO,

				 OP_ILLEGAL, GFP_NOIO);

out_fail:

	if (fail_return || !ff_layout_has_available_ds(lseg))

		pnfs_error_mark_layout_for_return(ino, lseg);

	ds = NULL;

	}

out:

	return ds;

}