fuse: add per-page descriptor <offset, length> to fuse_req

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.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 28d9792..db4af8f 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -35,15 +35,18 @@ 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(pages, 0, sizeof(*pages) * npages);
+       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;
 }
 
@@ -52,18 +55,25 @@ static struct fuse_req *__fuse_request_alloc(unsigned 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;
 }
@@ -81,8 +91,10 @@ struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
 
 void fuse_request_free(struct fuse_req *req)
 {
-       if (req->pages != req->inline_pages)
+       if (req->pages != req->inline_pages) {
                kfree(req->pages);
+               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);
@@ -891,7 +903,7 @@ 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++) {
@@ -1599,7 +1611,7 @@ 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 fdb5b33..2b6f08a 100644 (file)
--- 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 5b21e6a..70cef60 100644 (file)
--- 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;