3.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: Trond Myklebust <[email protected]> commit 6db6dd7d3fd8f7c765dabc376493d6791ab28bd6 upstream. 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. Signed-off-by: Trond Myklebust <[email protected]> Cc: Weston Andros Adamson <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Bruce Fields <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfs/read.c | 10 +++++++--- fs/nfs/write.c | 10 +++++++--- 2 files changed, 14 insertions(+), 6 deletions(-) --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -91,12 +91,16 @@ void nfs_readdata_release(struct nfs_rea 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); --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -126,12 +126,16 @@ void nfs_writedata_release(struct nfs_wr 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
