From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: target-devel@vger.kernel.org, nab@linux-iscsi.org, hch@lst.de,
roland@kernel.org
Subject: [PATCH 04/11] target: support zero-size allocation lengths in transport_kmap_data_sg
Date: Fri, 7 Sep 2012 17:30:35 +0200 [thread overview]
Message-ID: <1347031842-2531-5-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1347031842-2531-1-git-send-email-pbonzini@redhat.com>
In order to support zero-size allocation lengths, do not assert
that we have a scatterlist until after checking cmd->data_length.
But once we do this, we can have two cases of transport_kmap_data_sg
returning NULL: a zero-size allocation length, or an out-of-memory
condition. Report the latter using sense codes, so that the SCSI
command that triggered it will fail.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
drivers/target/target_core_transport.c | 13 +++++++++----
1 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 2e55aa9..8facb74 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2185,7 +2185,6 @@ void *transport_kmap_data_sg(struct se_cmd *cmd)
struct page **pages;
int i;
- BUG_ON(!sg);
/*
* We need to take into account a possible offset here for fabrics like
* tcm_loop who may be using a contig buffer from the SCSI midlayer for
@@ -2193,13 +2192,17 @@ void *transport_kmap_data_sg(struct se_cmd *cmd)
*/
if (!cmd->t_data_nents)
return NULL;
- else if (cmd->t_data_nents == 1)
+
+ BUG_ON(!sg);
+ if (cmd->t_data_nents == 1)
return kmap(sg_page(sg)) + sg->offset;
/* >1 page. use vmap */
pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
- if (!pages)
+ if (!pages) {
+ cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
return NULL;
+ }
/* convert sg[] to pages[] */
for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
@@ -2208,8 +2211,10 @@ void *transport_kmap_data_sg(struct se_cmd *cmd)
cmd->t_data_vmap = vmap(pages, cmd->t_data_nents, VM_MAP, PAGE_KERNEL);
kfree(pages);
- if (!cmd->t_data_vmap)
+ if (!cmd->t_data_vmap) {
+ cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
return NULL;
+ }
return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
}
--
1.7.1
next prev parent reply other threads:[~2012-09-07 15:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-07 15:30 [PATCH 00/11] lots of fixes for zero allocation length Paolo Bonzini
2012-09-07 15:30 ` [PATCH 01/11] target: go through normal processing for zero-length PSCSI commands Paolo Bonzini
2012-09-07 18:06 ` Nicholas A. Bellinger
2012-09-07 15:30 ` [PATCH 02/11] target: report too-small parameter lists everywhere Paolo Bonzini
2012-09-07 18:09 ` Nicholas A. Bellinger
2012-09-07 15:30 ` [PATCH 03/11] target: fail REPORT LUNS with less than 16 bytes of payload Paolo Bonzini
2012-09-07 18:09 ` Nicholas A. Bellinger
2012-09-07 15:30 ` Paolo Bonzini [this message]
2012-09-07 18:12 ` [PATCH 04/11] target: support zero-size allocation lengths in transport_kmap_data_sg Nicholas A. Bellinger
2012-09-07 15:30 ` [PATCH 05/11] target: support zero allocation length in REQUEST SENSE Paolo Bonzini
2012-09-07 18:17 ` Nicholas A. Bellinger
2012-09-07 15:30 ` [PATCH 06/11] target: go through normal processing for zero-length REQUEST_SENSE Paolo Bonzini
2012-09-07 18:23 ` Nicholas A. Bellinger
2012-09-07 18:33 ` Nicholas A. Bellinger
2012-09-07 20:34 ` Paolo Bonzini
2012-09-07 15:30 ` [PATCH 07/11] target: support zero allocation length in INQUIRY Paolo Bonzini
2012-09-07 15:30 ` [PATCH 08/11] target: fix truncation of mode data, support zero allocation length Paolo Bonzini
2012-09-07 15:30 ` [PATCH 09/11] target: support zero allocation length in SBC commands Paolo Bonzini
2012-09-07 15:30 ` [PATCH 10/11] target: do not submit a zero-bio I/O request Paolo Bonzini
2012-09-07 15:30 ` [PATCH 11/11] target: go through normal processing for all zero-length commands Paolo Bonzini
2012-09-07 19:01 ` [PATCH 00/11] lots of fixes for zero allocation length Nicholas A. Bellinger
2012-09-10 7:28 ` Christoph Hellwig
2012-09-10 7:48 ` Paolo Bonzini
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