From: Long Li <longli@microsoft.com>
Date: Wed, 30 May 2018 12:47:56 -0700
Subject: [PATCH] CIFS: Add support for direct pages in wdata
Git-commit: 8e7360f67e75e06f3ea144354243728fb8f54c57
Patch-mainline: v4.17
References: bsc#1144333
Add a function to allocate wdata without allocating pages for data
transfer. This gives the caller an option to pass a number of pages that
point to the data buffer to write to.
wdata is reponsible for free those pages after it's done.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/cifsglob.h | 2 +-
fs/cifs/cifsproto.h | 2 ++
fs/cifs/cifssmb.c | 17 ++++++++++++++---
3 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 781c2af609e5..08d1cdd96701 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1211,7 +1211,7 @@ struct cifs_writedata {
unsigned int tailsz;
unsigned int credits;
unsigned int nr_pages;
- struct page *pages[];
+ struct page **pages;
};
/*
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 1f27d8e9dd26..7933c5f9c076 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -533,6 +533,8 @@ int cifs_async_writev(struct cifs_writedata *wdata,
void cifs_writev_complete(struct work_struct *work);
struct cifs_writedata *cifs_writedata_alloc(unsigned int nr_pages,
work_func_t complete);
+struct cifs_writedata *cifs_writedata_direct_alloc(struct page **pages,
+ work_func_t complete);
void cifs_writedata_release(struct kref *refcount);
int cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index c8e42785d261..5aca336642c0 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1952,6 +1952,7 @@ cifs_writedata_release(struct kref *refcount)
if (wdata->cfile)
cifsFileInfo_put(wdata->cfile);
+ kvfree(wdata->pages);
kfree(wdata);
}
@@ -2074,13 +2075,23 @@ cifs_writev_complete(struct work_struct *work)
struct cifs_writedata *
cifs_writedata_alloc(unsigned int nr_pages, work_func_t complete)
+{
+ struct page **pages =
+ kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
+ if (pages)
+ return cifs_writedata_direct_alloc(pages, complete);
+
+ return NULL;
+}
+
+struct cifs_writedata *
+cifs_writedata_direct_alloc(struct page **pages, work_func_t complete)
{
struct cifs_writedata *wdata;
- /* writedata + number of page pointers */
- wdata = kzalloc(sizeof(*wdata) +
- sizeof(struct page *) * nr_pages, GFP_NOFS);
+ wdata = kzalloc(sizeof(*wdata), GFP_NOFS);
if (wdata != NULL) {
+ wdata->pages = pages;
kref_init(&wdata->refcount);
INIT_LIST_HEAD(&wdata->list);
init_completion(&wdata->done);
--
2.16.4