RE: [Patch v2 02/15] CIFS: Add support for direct pages in rdata

["Ruhl, Michael J" <michael.j.ruhl@intel.com>]

>-----Original Message-----
>From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
>owner@vger.kernel.org] On Behalf Of Long Li
>Sent: Wednesday, May 30, 2018 3:48 PM
>To: Steve French <sfrench@samba.org>; linux-cifs@vger.kernel.org; samba-
>technical@lists.samba.org; linux-kernel@vger.kernel.org; linux-
>rdma@vger.kernel.org
>Cc: Long Li <longli@microsoft.com>
>Subject: [Patch v2 02/15] CIFS: Add support for direct pages in rdata
>
>From: Long Li <longli@microsoft.com>
>
>Add a function to allocate rdata without allocating pages for data
>transfer. This gives the caller an option to pass a number of pages
>that point to the data buffer.
>
>rdata is still reponsible for free those pages after it's done.
>
>Signed-off-by: Long Li <longli@microsoft.com>
>---
> fs/cifs/cifsglob.h |  2 +-
> fs/cifs/file.c     | 23 ++++++++++++++++++++---
> 2 files changed, 21 insertions(+), 4 deletions(-)
>
>diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
>index 8d16c3e..56864a87 100644
>--- a/fs/cifs/cifsglob.h
>+++ b/fs/cifs/cifsglob.h
>@@ -1179,7 +1179,7 @@ struct cifs_readdata {
> 	unsigned int			tailsz;
> 	unsigned int			credits;
> 	unsigned int			nr_pages;
>-	struct page			*pages[];
>+	struct page			**pages;
> };
>
> struct cifs_writedata;
>diff --git a/fs/cifs/file.c b/fs/cifs/file.c
>index 23fd430..1c98293 100644
>--- a/fs/cifs/file.c
>+++ b/fs/cifs/file.c
>@@ -2880,13 +2880,13 @@ cifs_strict_writev(struct kiocb *iocb, struct
>iov_iter *from)
> }
>
> static struct cifs_readdata *
>-cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
>+cifs_readdata_direct_alloc(struct page **pages, work_func_t complete)
> {
> 	struct cifs_readdata *rdata;
>
>-	rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
>-			GFP_KERNEL);
>+	rdata = kzalloc(sizeof(*rdata), GFP_KERNEL);
> 	if (rdata != NULL) {
>+		rdata->pages = pages;
> 		kref_init(&rdata->refcount);
> 		INIT_LIST_HEAD(&rdata->list);
> 		init_completion(&rdata->done);
>@@ -2896,6 +2896,22 @@ cifs_readdata_alloc(unsigned int nr_pages,
>work_func_t complete)
> 	return rdata;
> }
>
>+static struct cifs_readdata *
>+cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
>+{
>+	struct page **pages =
>+		kzalloc(sizeof(struct page *) * nr_pages, GFP_KERNEL);
>+	struct cifs_readdata *ret = NULL;
>+
>+	if (pages) {
>+		ret = cifs_readdata_direct_alloc(pages, complete);
>+		if (!ret)
>+			kfree(pages);
>+	}
>+
>+	return ret;
>+}
>+
> void
> cifs_readdata_release(struct kref *refcount)
> {
>@@ -2910,6 +2926,7 @@ cifs_readdata_release(struct kref *refcount)
> 	if (rdata->cfile)
> 		cifsFileInfo_put(rdata->cfile);
>
>+	kvfree(rdata->pages);

Is the kvfree() correct?

You use kzalloc() and kfree in cifs_readdata_alloc().

Mike

> 	kfree(rdata);
> }
>
>--
>2.7.4
>
>--
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