fuse: general infrastructure for pages[] of variable size
The patch removes inline array of FUSE_MAX_PAGES_PER_REQ page pointers from
fuse_req. Instead of that, req->pages may now point either to small inline
array or to an array allocated dynamically.
This essentially means that all callers of fuse_request_alloc[_nofs] should
pass the number of pages needed explicitly.
The patch doesn't make any logic changes.
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 05c3eec2..af37ae1 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -34,34 +34,55 @@
return file->private_data;
}
-static void fuse_request_init(struct fuse_req *req)
+static void fuse_request_init(struct fuse_req *req, struct page **pages,
+ unsigned npages)
{
memset(req, 0, sizeof(*req));
+ memset(pages, 0, sizeof(*pages) * 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->max_pages = npages;
}
-struct fuse_req *fuse_request_alloc(void)
+static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
{
- struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
- if (req)
- fuse_request_init(req);
+ struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
+ if (req) {
+ struct page **pages;
+
+ if (npages <= FUSE_REQ_INLINE_PAGES)
+ pages = req->inline_pages;
+ else
+ pages = kmalloc(sizeof(struct page *) * npages, flags);
+
+ if (!pages) {
+ kmem_cache_free(fuse_req_cachep, req);
+ return NULL;
+ }
+
+ fuse_request_init(req, pages, npages);
+ }
return req;
}
+
+struct fuse_req *fuse_request_alloc(unsigned npages)
+{
+ return __fuse_request_alloc(npages, GFP_KERNEL);
+}
EXPORT_SYMBOL_GPL(fuse_request_alloc);
-struct fuse_req *fuse_request_alloc_nofs(void)
+struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
{
- struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_NOFS);
- if (req)
- fuse_request_init(req);
- return req;
+ return __fuse_request_alloc(npages, GFP_NOFS);
}
void fuse_request_free(struct fuse_req *req)
{
+ if (req->pages != req->inline_pages)
+ kfree(req->pages);
kmem_cache_free(fuse_req_cachep, req);
}
@@ -116,7 +137,7 @@
if (!fc->connected)
goto out;
- req = fuse_request_alloc();
+ req = fuse_request_alloc(FUSE_MAX_PAGES_PER_REQ);
err = -ENOMEM;
if (!req)
goto out;
@@ -165,7 +186,7 @@
struct fuse_file *ff = file->private_data;
spin_lock(&fc->lock);
- fuse_request_init(req);
+ fuse_request_init(req, req->pages, req->max_pages);
BUG_ON(ff->reserved_req);
ff->reserved_req = req;
wake_up_all(&fc->reserved_req_waitq);
@@ -192,7 +213,7 @@
atomic_inc(&fc->num_waiting);
wait_event(fc->blocked_waitq, !fc->blocked);
- req = fuse_request_alloc();
+ req = fuse_request_alloc(FUSE_MAX_PAGES_PER_REQ);
if (!req)
req = get_reserved_req(fc, file);