FAILED: patch "[PATCH] NFSv4/pnfs: Free the netid when draining a data-server" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x a7c8e96d1b9fa327cbdea514d047c8295b28d49a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026110414-pebble-stimulus-c18a@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a7c8e96d1b9fa327cbdea514d047c8295b28d49a Mon Sep 17 00:00:00 2001
From: Benjamin Coddington <ben.coddington@hammerspace.com>
Date: Tue, 15 Sep 2026 08:22:03 -0400
Subject: [PATCH] NFSv4/pnfs: Free the netid when draining a data-server
 address list

nfs4_pnfs_ds_addr_free() releases all three of an address entry's
allocations, but the four sites that drain a decoded list before it
reaches a data server open-code the loop and free only da_remotestr and
the entry, leaking da_netid.  Both layout drivers drain that list when
nfs4_pnfs_ds_add() returned a data server already in the cache, and
again on their error exits.

Lift the drain into nfs4_pnfs_ds_addr_list_free() so an address list has
one owner.  A striping mount reaches the cached case on nearly every
GETDEVICEINFO, since many deviceIDs name the same data servers.

Fixes: 4be78d26810b ("NFSv4/pNFS: Store the transport type in struct nfs4_pnfs_ds_addr")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: Benjamin Coddington <bcodding@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>

diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c
index 88bc79ec3459..57e0654cd98c 100644
--- a/fs/nfs/filelayout/filelayoutdev.c
+++ b/fs/nfs/filelayout/filelayoutdev.c
@@ -177,27 +177,14 @@ nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 		trace_fl_getdevinfo(server, &pdev->dev_id, dsaddr->ds_list[i]->ds_remotestr);
 
 		/* If DS was already in cache, free ds addrs */
-		while (!list_empty(&dsaddrs)) {
-			da = list_first_entry(&dsaddrs,
-					      struct nfs4_pnfs_ds_addr,
-					      da_node);
-			list_del_init(&da->da_node);
-			kfree(da->da_remotestr);
-			kfree(da);
-		}
+		nfs4_pnfs_ds_addr_list_free(&dsaddrs);
 	}
 
 	folio_put(scratch);
 	return dsaddr;
 
 out_err_drain_dsaddrs:
-	while (!list_empty(&dsaddrs)) {
-		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
-				      da_node);
-		list_del_init(&da->da_node);
-		kfree(da->da_remotestr);
-		kfree(da);
-	}
+	nfs4_pnfs_ds_addr_list_free(&dsaddrs);
 out_err_free_deviceid:
 	nfs4_fl_free_deviceid(dsaddr);
 	/* stripe_indicies was part of dsaddr */
diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
index 5c0216bd5fce..6cd3859d4a24 100644
--- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -159,26 +159,13 @@ nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 		goto out_err_drain_dsaddrs;
 
 	/* If DS was already in cache, free ds addrs */
-	while (!list_empty(&dsaddrs)) {
-		da = list_first_entry(&dsaddrs,
-				      struct nfs4_pnfs_ds_addr,
-				      da_node);
-		list_del_init(&da->da_node);
-		kfree(da->da_remotestr);
-		kfree(da);
-	}
+	nfs4_pnfs_ds_addr_list_free(&dsaddrs);
 
 	folio_put(scratch);
 	return new_ds;
 
 out_err_drain_dsaddrs:
-	while (!list_empty(&dsaddrs)) {
-		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
-				      da_node);
-		list_del_init(&da->da_node);
-		kfree(da->da_remotestr);
-		kfree(da);
-	}
+	nfs4_pnfs_ds_addr_list_free(&dsaddrs);
 
 	kfree(ds_versions);
 out_scratch:
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 70d20f779678..5725ea06efc2 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -427,6 +427,7 @@ int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
 struct nfs4_pnfs_ds_addr *nfs4_decode_mp_ds_addr(struct net *net,
 						 struct xdr_stream *xdr,
 						 gfp_t gfp_flags);
+void nfs4_pnfs_ds_addr_list_free(struct list_head *dsaddrs);
 void pnfs_layout_mark_request_commit(struct nfs_page *req,
 				     struct pnfs_layout_segment *lseg,
 				     struct nfs_commit_info *cinfo,
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 93d63f75a355..5bd014b981bf 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -633,23 +633,28 @@ static void nfs4_pnfs_ds_addr_free(struct nfs4_pnfs_ds_addr *da)
 	kfree(da);
 }
 
-static void destroy_ds(struct nfs4_pnfs_ds *ds)
+void nfs4_pnfs_ds_addr_list_free(struct list_head *dsaddrs)
 {
 	struct nfs4_pnfs_ds_addr *da;
 
+	while (!list_empty(dsaddrs)) {
+		da = list_first_entry(dsaddrs, struct nfs4_pnfs_ds_addr,
+				      da_node);
+		list_del_init(&da->da_node);
+		nfs4_pnfs_ds_addr_free(da);
+	}
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_addr_list_free);
+
+static void destroy_ds(struct nfs4_pnfs_ds *ds)
+{
 	dprintk("--> %s\n", __func__);
 	ifdebug(FACILITY)
 		print_ds(ds);
 
 	nfs_put_client(ds->ds_clp);
 
-	while (!list_empty(&ds->ds_addrs)) {
-		da = list_first_entry(&ds->ds_addrs,
-				      struct nfs4_pnfs_ds_addr,
-				      da_node);
-		list_del_init(&da->da_node);
-		nfs4_pnfs_ds_addr_free(da);
-	}
+	nfs4_pnfs_ds_addr_list_free(&ds->ds_addrs);
 
 	kfree(ds->ds_remotestr);
 	kfree(ds);