From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751797Ab0IVIJd (ORCPT ); Wed, 22 Sep 2010 04:09:33 -0400 Received: from nm28-vm0.bullet.mail.ne1.yahoo.com ([98.138.91.22]:42523 "HELO nm28-vm0.bullet.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751316Ab0IVIJc (ORCPT ); Wed, 22 Sep 2010 04:09:32 -0400 X-Greylist: delayed 409 seconds by postgrey-1.27 at vger.kernel.org; Wed, 22 Sep 2010 04:09:32 EDT X-Yahoo-Newman-Id: 913354.4939.bm@omp1023.mail.ne1.yahoo.com X-Yahoo-SMTP: fzDSGlOswBCWnIOrNw7KwwK1j9PqyNbe5PtLKiS4dDU.UNl_t6bdEZu9tTLW X-YMail-OSG: DhsfIaUVM1nTcyD5d1uSGlfpkPKVQ8MXPdx5sbrrTBLZHBN tuJJNXA9lqVdCc6sVc3fJFMnIMQUI0EwpcxuEAF5eeFznuhnaSUE.t1gLIye AaubQqw35xguGJnXH7q46HEv4KgciK2uMFiRZU7TwoUMXmIR3pz6QNHedfK6 wke3EYBWlWqHea.zwjIf05fhmL3EM9KH5hkVBeCe2QNUEMbe9TIDlCcpiw9q 27PKb_GcvNkslUJ6ZtDjTinU12iM3UZJLfodfuiIIrNrr.6YDTfzUDaIurHt fgkuM_lbRtJGJ2az25bOycAdFgtsjdZqe3ofXPsq56mHiFCjyy_B2yi4- X-Yahoo-Newman-Property: ymail-3 From: "Nicholas A. Bellinger" To: linux-kernel , linux-scsi , Christoph Hellwig , FUJITA Tomonori , Mike Christie Cc: Fubo Chen , Nicholas Bellinger Subject: [PATCH] tcm/fileio: Convert to iov allocations for fd_do_readv() and fd_do_writev() Date: Wed, 22 Sep 2010 01:02:38 -0700 Message-Id: <1285142558-13219-1-git-send-email-nab@linux-iscsi.org> X-Mailer: git-send-email 1.5.6.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Bellinger Greetings all, This patch converts target_core_file.c fd_do_readv() and fd_do_writev() code to use dynamic allocation for *iov[] instead of local scope static memory to properly handle cases with TCM_Loop that can potentially exceed the 8K stack on 64-bit kernels with per 1:1 struct scatterlist <-> 512-byte block_size SGL length mapping up to the current FD_MAX_SECTORS=1024. For more information please see: http://lkml.org/lkml/2010/9/22/42 Many thanks to Fubo Chen for spotting this one! Signed-off-by: Nicholas A. Bellinger --- drivers/target/target_core_file.c | 20 ++++++++++++++++---- 1 files changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index 221b41e..93d3f63 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -476,12 +476,16 @@ static int fd_do_readv(struct fd_request *req, struct se_task *task) { struct file *fd = req->fd_dev->fd_file; struct scatterlist *sg = task->task_sg; - struct iovec iov[req->fd_sg_count]; + struct iovec *iov; mm_segment_t old_fs; loff_t pos = (req->fd_lba * DEV_ATTRIB(task->se_dev)->block_size); int ret = 0, i; - memset(iov, 0, sizeof(struct iovec) * req->fd_sg_count); + iov = kzalloc(sizeof(struct iovec) * req->fd_sg_count, GFP_KERNEL); + if (!(iov)) { + printk(KERN_ERR "Unable to allocate fd_do_readv iov[]\n"); + return -1; + } for (i = 0; i < req->fd_sg_count; i++) { iov[i].iov_len = sg[i].length; @@ -492,6 +496,8 @@ static int fd_do_readv(struct fd_request *req, struct se_task *task) set_fs(get_ds()); ret = vfs_readv(fd, &iov[0], req->fd_sg_count, &pos); set_fs(old_fs); + + kfree(iov); /* * Return zeros and GOOD status even if the READ did not return * the expected virt_size for struct file w/o a backing struct @@ -583,12 +589,16 @@ static int fd_do_writev(struct fd_request *req, struct se_task *task) { struct file *fd = req->fd_dev->fd_file; struct scatterlist *sg = task->task_sg; - struct iovec iov[req->fd_sg_count]; + struct iovec *iov; mm_segment_t old_fs; loff_t pos = (req->fd_lba * DEV_ATTRIB(task->se_dev)->block_size); int ret, i = 0; - memset(iov, 0, sizeof(struct iovec) * req->fd_sg_count); + iov = kzalloc(sizeof(struct iovec) * req->fd_sg_count, GFP_KERNEL); + if (!(iov)) { + printk(KERN_ERR "Unable to allocate fd_do_writev iov[]\n"); + return -1; + } for (i = 0; i < req->fd_sg_count; i++) { iov[i].iov_len = sg[i].length; @@ -600,6 +610,8 @@ static int fd_do_writev(struct fd_request *req, struct se_task *task) ret = vfs_writev(fd, &iov[0], req->fd_sg_count, &pos); set_fs(old_fs); + kfree(iov); + if (ret < 0 || ret != req->fd_size) { printk(KERN_ERR "vfs_writev() returned %d\n", ret); return -1; -- 1.5.6.5