On Fri, Jan 04, 2013 at 01:15:01PM -0500, Trond Myklebust wrote:
> This patch ensures that we free the rpc_task after the cleanup callbacks
> are done in order to avoid a deadlock problem that can be triggered if
> the callback needs to wait for another workqueue item to complete.
Makes sense to me!
(Dumb question: so read and write data are the only two cases where the
calldata embeds an rpc task? Why is that?)
--b.
>
> Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> Cc: Weston Andros Adamson <dros@xxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Bruce Fields <bfields@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx [>= 3.5]
> ---
> fs/nfs/read.c | 10 +++++++---
> fs/nfs/write.c | 10 +++++++---
> 2 files changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index b6bdb18..a5e5d98 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -91,12 +91,16 @@ void nfs_readdata_release(struct nfs_read_data *rdata)
> put_nfs_open_context(rdata->args.context);
> if (rdata->pages.pagevec != rdata->pages.page_array)
> kfree(rdata->pages.pagevec);
> - if (rdata != &read_header->rpc_data)
> - kfree(rdata);
> - else
> + if (rdata == &read_header->rpc_data) {
> rdata->header = NULL;
> + rdata = NULL;
> + }
> if (atomic_dec_and_test(&hdr->refcnt))
> hdr->completion_ops->completion(hdr);
> + /* Note: we only free the rpc_task after callbacks are done.
> + * See the comment in rpc_free_task() for why
> + */
> + kfree(rdata);
> }
> EXPORT_SYMBOL_GPL(nfs_readdata_release);
>
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index b673be3..c483cc5 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -126,12 +126,16 @@ void nfs_writedata_release(struct nfs_write_data *wdata)
> put_nfs_open_context(wdata->args.context);
> if (wdata->pages.pagevec != wdata->pages.page_array)
> kfree(wdata->pages.pagevec);
> - if (wdata != &write_header->rpc_data)
> - kfree(wdata);
> - else
> + if (wdata == &write_header->rpc_data) {
> wdata->header = NULL;
> + wdata = NULL;
> + }
> if (atomic_dec_and_test(&hdr->refcnt))
> hdr->completion_ops->completion(hdr);
> + /* Note: we only free the rpc_task after callbacks are done.
> + * See the comment in rpc_free_task() for why
> + */
> + kfree(wdata);
> }
> EXPORT_SYMBOL_GPL(nfs_writedata_release);
>
> --
> 1.7.11.7
>
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
