Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752683AbZIHW5o (ORCPT ); Tue, 8 Sep 2009 18:57:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752661AbZIHW5m (ORCPT ); Tue, 8 Sep 2009 18:57:42 -0400 Received: from cobra.newdream.net ([66.33.216.30]:57539 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752498AbZIHW5i (ORCPT ); Tue, 8 Sep 2009 18:57:38 -0400 From: Sage Weil To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Sage Weil Subject: [PATCH 04/20] ceph: ref counted buffer Date: Tue, 8 Sep 2009 15:56:25 -0700 Message-Id: <1252450601-17610-5-git-send-email-sage@newdream.net> X-Mailer: git-send-email 1.5.6.5 In-Reply-To: <1252450601-17610-4-git-send-email-sage@newdream.net> References: <1252450601-17610-1-git-send-email-sage@newdream.net> <1252450601-17610-2-git-send-email-sage@newdream.net> <1252450601-17610-3-git-send-email-sage@newdream.net> <1252450601-17610-4-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: 2707 Lines: 118 struct ceph_buffer is a simple ref-counted buffer. We transparently choose between kmalloc for small buffers and vmalloc for large ones. This is used for allocating memory for xattr data, among other things. Signed-off-by: Sage Weil --- fs/ceph/buffer.h | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 93 insertions(+), 0 deletions(-) create mode 100644 fs/ceph/buffer.h diff --git a/fs/ceph/buffer.h b/fs/ceph/buffer.h new file mode 100644 index 0000000..b4ccb94 --- /dev/null +++ b/fs/ceph/buffer.h @@ -0,0 +1,93 @@ +#ifndef __FS_CEPH_BUFFER_H +#define __FS_CEPH_BUFFER_H + +#include +#include +#include + +#include "ceph_debug.h" + +/* + * 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_static, is_vmalloc; +}; + +static inline void ceph_buffer_init_static(struct ceph_buffer *b) +{ + atomic_set(&b->nref, 1); + b->vec.iov_base = NULL; + b->vec.iov_len = 0; + b->alloc_len = 0; + b->is_static = true; +} + +static inline 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; + b->is_static = false; + return b; +} + +static inline int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp) +{ + if (len <= PAGE_SIZE) { + b->vec.iov_base = kmalloc(len, gfp); + 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; +} + +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 -- 1.5.6.5 -- 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/