From 4250c0668ea10a19f3d37b1733f54ce6c8a37234 Mon Sep 17 00:00:00 2001 From: Maxim Patlasov Date: Fri, 26 Oct 2012 19:48:07 +0400 Subject: [PATCH] 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 Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 47 ++++++++++++++++++++++++++++++++++------------- fs/fuse/file.c | 4 ++-- fs/fuse/fuse_i.h | 15 ++++++++++++--- fs/fuse/inode.c | 4 ++-- 4 files changed, 50 insertions(+), 20 deletions(-) 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 @@ static struct fuse_conn *fuse_get_conn(struct file *file) 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 @@ struct fuse_req *fuse_get_req(struct fuse_conn *fc) 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 @@ 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); + 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 @@ struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file) 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); diff --git a/fs/fuse/file.c b/fs/fuse/file.c index f3ab824..2565f63 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -57,7 +57,7 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) return NULL; ff->fc = fc; - ff->reserved_req = fuse_request_alloc(); + ff->reserved_req = fuse_request_alloc(0); if (unlikely(!ff->reserved_req)) { kfree(ff); return NULL; @@ -1272,7 +1272,7 @@ static int fuse_writepage_locked(struct page *page) set_page_writeback(page); - req = fuse_request_alloc_nofs(); + req = fuse_request_alloc_nofs(1); if (!req) goto err; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 5c50553..0c5b931 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -44,6 +44,9 @@ doing the mount will be allowed to access the filesystem */ #define FUSE_ALLOW_OTHER (1 << 1) +/** Number of page pointers embedded in fuse_req */ +#define FUSE_REQ_INLINE_PAGES 1 + /** List of active connections */ extern struct list_head fuse_conn_list; @@ -291,7 +294,13 @@ struct fuse_req { } misc; /** page vector */ - struct page *pages[FUSE_MAX_PAGES_PER_REQ]; + struct page **pages; + + /** size of the 'pages' array */ + unsigned max_pages; + + /** inline page vector */ + struct page *inline_pages[FUSE_REQ_INLINE_PAGES]; /** number of pages in vector */ unsigned num_pages; @@ -664,9 +673,9 @@ void fuse_ctl_cleanup(void); /** * Allocate a request */ -struct fuse_req *fuse_request_alloc(void); +struct fuse_req *fuse_request_alloc(unsigned npages); -struct fuse_req *fuse_request_alloc_nofs(void); +struct fuse_req *fuse_request_alloc_nofs(unsigned npages); /** * Free a request diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 6f7d574..9a937f0 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1037,12 +1037,12 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) /* only now - we want root dentry with NULL ->d_op */ sb->s_d_op = &fuse_dentry_operations; - init_req = fuse_request_alloc(); + init_req = fuse_request_alloc(0); if (!init_req) goto err_put_root; if (is_bdev) { - fc->destroy_req = fuse_request_alloc(); + fc->destroy_req = fuse_request_alloc(0); if (!fc->destroy_req) goto err_free_init_req; } -- 2.7.4