Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755639AbZLCXmo (ORCPT ); Thu, 3 Dec 2009 18:42:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755469AbZLCXlk (ORCPT ); Thu, 3 Dec 2009 18:41:40 -0500 Received: from cobra.newdream.net ([66.33.216.30]:36084 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266AbZLCXgP (ORCPT ); Thu, 3 Dec 2009 18:36:15 -0500 From: Sage Weil To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Sage Weil Subject: [PATCH 05/24] ceph: ref counted buffer Date: Thu, 3 Dec 2009 15:41:12 -0800 Message-Id: <1259883691-1042-6-git-send-email-sage@newdream.net> X-Mailer: git-send-email 1.6.5 In-Reply-To: <1259883691-1042-5-git-send-email-sage@newdream.net> References: <1259883691-1042-1-git-send-email-sage@newdream.net> <1259883691-1042-2-git-send-email-sage@newdream.net> <1259883691-1042-3-git-send-email-sage@newdream.net> <1259883691-1042-4-git-send-email-sage@newdream.net> <1259883691-1042-5-git-send-email-sage@newdream.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2865 Lines: 122 struct ceph_buffer is a simple ref-counted buffer. We transparently choose between kmalloc for small buffers and vmalloc for large ones. This is currently used only for allocating memory for xattr data. Signed-off-by: Sage Weil --- fs/ceph/buffer.c | 34 +++++++++++++++++++++++++++++++++ fs/ceph/buffer.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+), 0 deletions(-) create mode 100644 fs/ceph/buffer.c create mode 100644 fs/ceph/buffer.h diff --git a/fs/ceph/buffer.c b/fs/ceph/buffer.c new file mode 100644 index 0000000..cf9aacc --- /dev/null +++ b/fs/ceph/buffer.c @@ -0,0 +1,34 @@ + +#include "ceph_debug.h" +#include "buffer.h" + +struct ceph_buffer *ceph_buffer_new(gfp_t gfp) +{ + struct ceph_buffer *b; + + b = kmalloc(sizeof(*b), gfp); + if (!b) + return NULL; + atomic_set(&b->nref, 1); + b->vec.iov_base = NULL; + b->vec.iov_len = 0; + b->alloc_len = 0; + return b; +} + +int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp) +{ + b->vec.iov_base = kmalloc(len, gfp | __GFP_NOWARN); + if (b->vec.iov_base) { + b->is_vmalloc = false; + } else { + b->vec.iov_base = __vmalloc(len, gfp, PAGE_KERNEL); + b->is_vmalloc = true; + } + if (!b->vec.iov_base) + return -ENOMEM; + b->alloc_len = len; + b->vec.iov_len = len; + return 0; +} + diff --git a/fs/ceph/buffer.h b/fs/ceph/buffer.h new file mode 100644 index 0000000..16b1930 --- /dev/null +++ b/fs/ceph/buffer.h @@ -0,0 +1,55 @@ +#ifndef __FS_CEPH_BUFFER_H +#define __FS_CEPH_BUFFER_H + +#include +#include +#include +#include + +/* + * a simple reference counted buffer. + * + * use kmalloc for small sizes (<= one page), vmalloc for larger + * sizes. + */ +struct ceph_buffer { + atomic_t nref; + struct kvec vec; + size_t alloc_len; + bool is_vmalloc; +}; + +struct ceph_buffer *ceph_buffer_new(gfp_t gfp); +int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp); + +static inline struct ceph_buffer *ceph_buffer_get(struct ceph_buffer *b) +{ + atomic_inc(&b->nref); + return b; +} + +static inline void ceph_buffer_put(struct ceph_buffer *b) +{ + if (b && atomic_dec_and_test(&b->nref)) { + if (b->vec.iov_base) { + if (b->is_vmalloc) + vfree(b->vec.iov_base); + else + kfree(b->vec.iov_base); + } + kfree(b); + } +} + +static inline struct ceph_buffer *ceph_buffer_new_alloc(int len, gfp_t gfp) +{ + struct ceph_buffer *b = ceph_buffer_new(gfp); + + if (b && ceph_buffer_alloc(b, len, gfp) < 0) { + ceph_buffer_put(b); + b = NULL; + } + return b; +} + +#endif -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/