The patch below does not apply to the 4.4-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.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f57dcf4c72113c745d83f1c65f7291299f65c14f Mon Sep 17 00:00:00 2001
From: Trond Myklebust trond.myklebust@hammerspace.com Date: Wed, 13 Feb 2019 09:21:38 -0500 Subject: [PATCH] NFS: Fix I/O request leakages
When we fail to add the request to the I/O queue, we currently leave it to the caller to free the failed request. However since some of the requests that fail are actually created by nfs_pageio_add_request() itself, and are not passed back the caller, this leads to a leakage issue, which can again cause page locks to leak.
This commit addresses the leakage by freeing the created requests on error, using desc->pg_completion_ops->error_cleanup()
Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Fixes: a7d42ddb30997 ("nfs: add mirroring support to pgio layer") Cc: stable@vger.kernel.org # v4.0: c18b96a1b862: nfs: clean up rest of reqs Cc: stable@vger.kernel.org # v4.0: d600ad1f2bdb: NFS41: pop some layoutget Cc: stable@vger.kernel.org # v4.0+
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index e54d899c1848..301880a3ad8e 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -988,6 +988,17 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) } }
+static void +nfs_pageio_cleanup_request(struct nfs_pageio_descriptor *desc, + struct nfs_page *req) +{ + LIST_HEAD(head); + + nfs_list_remove_request(req); + nfs_list_add_request(req, &head); + desc->pg_completion_ops->error_cleanup(&head); +} + /** * nfs_pageio_add_request - Attempt to coalesce a request into a page list. * @desc: destination io descriptor @@ -1025,10 +1036,8 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, nfs_page_group_unlock(req); desc->pg_moreio = 1; nfs_pageio_doio(desc); - if (desc->pg_error < 0) - return 0; - if (mirror->pg_recoalesce) - return 0; + if (desc->pg_error < 0 || mirror->pg_recoalesce) + goto out_cleanup_subreq; /* retry add_request for this subreq */ nfs_page_group_lock(req); continue; @@ -1061,6 +1070,10 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, desc->pg_error = PTR_ERR(subreq); nfs_page_group_unlock(req); return 0; +out_cleanup_subreq: + if (req != subreq) + nfs_pageio_cleanup_request(desc, subreq); + return 0; }
static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) @@ -1168,11 +1181,14 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, if (nfs_pgio_has_mirroring(desc)) desc->pg_mirror_idx = midx; if (!nfs_pageio_add_request_mirror(desc, dupreq)) - goto out_failed; + goto out_cleanup_subreq; }
return 1;
+out_cleanup_subreq: + if (req != dupreq) + nfs_pageio_cleanup_request(desc, dupreq); out_failed: nfs_pageio_error_cleanup(desc); return 0;