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[PATCH 07/11] fuse: add per-page descriptor <offset, length> to fuse_req (v2) [message #48162 is a reply to message #47955] Mon, 01 October 2012 11:20 Go to previous messageGo to previous message
Maxim Patlasov is currently offline  Maxim Patlasov
Messages: 45
Registered: July 2012
Member
The ability to save page pointers along with lengths and offsets in fuse_req
will be useful to cover several iovec-s with a single fuse_req.

Per-request page_offset is removed because anybody who need it can use
req->page_descs[0].offset instead.

Changed in v2:
- replaced structure page_desc with fuse_page_desc

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
---
fs/fuse/dev.c | 26 +++++++++++++++++++-------
fs/fuse/file.c | 10 +++++-----
fs/fuse/fuse_i.h | 15 ++++++++++++---
3 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index b241a7d..72ad962 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -35,14 +35,17 @@ static struct fuse_conn *fuse_get_conn(struct file *file)
}

static void fuse_request_init(struct fuse_req *req, struct page **pages,
+ struct fuse_page_desc *page_descs,
unsigned npages)
{
memset(req, 0, sizeof(*req));
+ memset(page_descs, 0, sizeof(*page_descs) * npages);
INIT_LIST_HEAD(&req->list);
INIT_LIST_HEAD(&req->intr_entry);
init_waitqueue_head(&req->waitq);
atomic_set(&req->count, 1);
req->pages = pages;
+ req->page_descs = page_descs;
req->max_pages = npages;
}

@@ -51,18 +54,25 @@ static struct fuse_req *__fuse_request_alloc(int npages, gfp_t flags)
struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
if (req) {
struct page **pages;
+ struct fuse_page_desc *page_descs;

- if (npages <= FUSE_REQ_INLINE_PAGES)
+ if (npages <= FUSE_REQ_INLINE_PAGES) {
pages = req->inline_pages;
- else
+ page_descs = req->inline_page_descs;
+ } else {
pages = kmalloc(sizeof(struct page *) * npages, flags);
+ page_descs = kmalloc(sizeof(struct fuse_page_desc) *
+ npages, flags);
+ }

- if (!pages) {
+ if (!pages || !page_descs) {
+ kfree(pages);
+ kfree(page_descs);
kmem_cache_free(fuse_req_cachep, req);
return NULL;
}

- fuse_request_init(req, pages, npages);
+ fuse_request_init(req, pages, page_descs, npages);
}
return req;
}
@@ -82,6 +92,8 @@ void fuse_request_free(struct fuse_req *req)
{
if (req->pages != req->inline_pages)
kfree(req->pages);
+ if (req->page_descs != req->inline_page_descs)
+ kfree(req->page_descs);
kmem_cache_free(fuse_req_cachep, req);
}

@@ -186,7 +198,7 @@ static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
struct fuse_file *ff = file->private_data;

spin_lock(&fc->lock);
- fuse_request_init(req, req->pages, req->max_pages);
+ fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
BUG_ON(ff->reserved_req);
ff->reserved_req = req;
wake_up_all(&fc->reserved_req_waitq);
@@ -877,7 +889,7 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
{
unsigned i;
struct fuse_req *req = cs->req;
- unsigned offset = req->page_offset;
+ unsigned offset = req->page_descs[0].offset;
unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset);

for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
@@ -1585,7 +1597,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
req->in.h.nodeid = outarg->nodeid;
req->in.numargs = 2;
req->in.argpages = 1;
- req->page_offset = offset;
+ req->page_descs[0].offset = offset;
req->end = fuse_retrieve_end;

index = outarg->offset >> PAGE_CACHE_SHIFT;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 08899a6..b68cf3b 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -798,7 +798,7 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,

res = fuse_send_write(req, file, pos, count, NULL);

- offset = req->page_offset;
+ offset = req->page_descs[0].offset;
count = res;
for (i = 0; i < req->num_pages; i++) {
struct page *page = req->pages[i];
@@ -829,7 +829,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
int err;

req->in.argpages = 1;
- req->page_offset = offset;
+ req->page_descs[0].offset = offset;

do {
size_t tmp;
@@ -1070,14 +1070,14 @@ static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
return npages;

req->num_pages = npages;
- req->page_offset = offset;
+ req->page_descs[0].offset = offset;

if (write)
req->in.argpages = 1;
else
req->out.argpages = 1;

- nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
+ nbytes = (req->num_pages << PAGE_SHIFT) - req->page_descs[0].offset;
*nbytesp = min(*nbytesp, nbytes);

return 0;
@@ -1314,7 +1314,7 @@ static int fuse_writepage_locked(struct page *page)
req->in.argpages = 1;
req->num_pages = 1;
req->pages[0] = tmp_page;
- req->page_offset = 0;
+ req->page_descs[0].offset = 0;
req->end = fuse_writepage_end;
req->inode = inode;

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index fd69d62..c07e454 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -203,6 +203,12 @@ struct fuse_out {
struct fuse_arg args[3];
};

+/** FUSE page descriptor */
+struct fuse_page_desc {
+ unsigned int length;
+ unsigned int offset;
+};
+
/** The request state */
enum fuse_req_state {
FUSE_REQ_INIT = 0,
@@ -296,18 +302,21 @@ struct fuse_req {
/** page vector */
struct page **pages;

+ /** page-descriptor vector */
+ struct fuse_page_desc *page_descs;
+
/** size of the 'pages' array */
unsigned max_pages;

/** inline page vector */
struct page *inline_pages[FUSE_REQ_INLINE_PAGES];

+ /** inline page-descriptor vector */
+ struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
+
/** number of pages in vector */
unsigned num_pages;

- /** offset of data on first page */
- unsigned page_offset;
-
/** File used in the request (or NULL) */
struct fuse_file *ff;
 
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