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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: a7d42ddb30 ("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+
This commit is contained in:
Trond Myklebust 2019-02-13 09:21:38 -05:00
parent 2137397c92
commit f57dcf4c72
1 changed files with 21 additions and 5 deletions
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26
fs/nfs/pagelist.c
View File

@ -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;