Skip to contentSkip to conversation

Patch "pNFS: Prevent the layout header refcount going to zero in pnfs_roc()" has been added to the 4.14-stable tree

PATCH [email protected] 1 participant 1 message Mar 13, 2018

Subsystems (2)
Stable branch NFS client
lore
Share & tools
lore

[email protected]

author maintainer Applied
#0 lore raw

This is a note to let you know that I've just added the patch titled

pNFS: Prevent the layout header refcount going to zero in pnfs_roc()

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
pnfs-prevent-the-layout-header-refcount-going-to-zero-in-pnfs_roc.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 9c6376ebddad585da4238532dd6d90ae23ffee67 Mon Sep 17 00:00:00 2001

From: Trond Myklebust <[email protected]>
Date: Wed, 7 Mar 2018 14:49:06 -0500
Subject: pNFS: Prevent the layout header refcount going to zero in pnfs_roc()

From: Trond Myklebust <[email protected]>

commit 9c6376ebddad585da4238532dd6d90ae23ffee67 upstream.

Ensure that we hold a reference to the layout header when processing the pNFS return-on-close so that the refcount value does not inadvertently go to zero.

Reported-by Tigran Mkrtchyan <[email protected]>
Signed-off-by Trond Myklebust <[email protected]>
Cc [email protected] # v4.10+
Tested-by Tigran Mkrtchyan <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 fs/nfs/pnfs.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
fs/nfs/pnfs.c +10 -3
@@ -292,8 +292,11 @@ pnfs_detach_layout_hdr(struct pnfs_layou
 void
 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 {
-	struct inode *inode = lo->plh_inode;
+	struct inode *inode;
 
+	if (!lo)
+		return;
+	inode = lo->plh_inode;
 	pnfs_layoutreturn_before_put_layout_hdr(lo);
 
 	if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {

@@ -1223,10 +1226,12 @@ retry:
 	spin_lock(&ino->i_lock);
 	lo = nfsi->layout;
 	if (!lo || !pnfs_layout_is_valid(lo) ||
-	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
+	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+		lo = NULL;
 		goto out_noroc;
+	}
+	pnfs_get_layout_hdr(lo);
 	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
-		pnfs_get_layout_hdr(lo);
 		spin_unlock(&ino->i_lock);
 		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
 				TASK_UNINTERRUPTIBLE);

@@ -1294,10 +1299,12 @@ out_noroc:
 		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 		if (ld->prepare_layoutreturn)
 			ld->prepare_layoutreturn(args);
+		pnfs_put_layout_hdr(lo);
 		return true;
 	}
 	if (layoutreturn)
 		pnfs_send_layoutreturn(lo, &stateid, iomode, true);
+	pnfs_put_layout_hdr(lo);
 	return false;
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/nfs-fix-unstable-write-completion.patch queue-4.14/nfs-fix-an-incorrect-type-in-struct-nfs_direct_req.patch queue-4.14/pnfs-prevent-the-layout-header-refcount-going-to-zero-in-pnfs_roc.patch