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authorNicholas Bellinger <nab@daterainc.com>2013-08-20 21:45:16 +0400
committerNicholas Bellinger <nab@linux-iscsi.org>2013-09-10 01:29:33 +0400
commit47e459e622f07c2564e6be8412d75389d2a807b8 (patch)
tree685709343f949e5cc858e8657dba5d2bd79d91ca
parent8cefe07b5e9c2b0212ad6809a219e4489807a746 (diff)
downloadlinux-47e459e622f07c2564e6be8412d75389d2a807b8.tar.xz
target: Add transport_reset_sgl_orig() for COMPARE_AND_WRITE
After COMPARE_AND_WRITE completes it's comparision, the WRITE payload SGLs head expect to be updated to point from the verify instance of user data, to the write instance of user data. So for this special case, add transport_reset_sgl_orig() usage within transport_free_pages() and add se_cmd->t_data_[sg,nents]_orig members to save the original assignments. Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Martin Petersen <martin.petersen@oracle.com> Cc: Chris Mason <chris.mason@fusionio.com> Cc: James Bottomley <JBottomley@Parallels.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@daterainc.com>
-rw-r--r--drivers/target/target_core_transport.c21
-rw-r--r--include/target/target_core_base.h2
2 files changed, 22 insertions, 1 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index c974e1373c77..87d64add7874 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1991,10 +1991,29 @@ static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
kfree(sgl);
}
+static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
+{
+ /*
+ * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
+ * emulation, and free + reset pointers if necessary..
+ */
+ if (!cmd->t_data_sg_orig)
+ return;
+
+ kfree(cmd->t_data_sg);
+ cmd->t_data_sg = cmd->t_data_sg_orig;
+ cmd->t_data_sg_orig = NULL;
+ cmd->t_data_nents = cmd->t_data_nents_orig;
+ cmd->t_data_nents_orig = 0;
+}
+
static inline void transport_free_pages(struct se_cmd *cmd)
{
- if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
+ if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
+ transport_reset_sgl_orig(cmd);
return;
+ }
+ transport_reset_sgl_orig(cmd);
transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
cmd->t_data_sg = NULL;
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 4a26a18a24d6..7fdb3fae2961 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -478,7 +478,9 @@ struct se_cmd {
struct work_struct work;
struct scatterlist *t_data_sg;
+ struct scatterlist *t_data_sg_orig;
unsigned int t_data_nents;
+ unsigned int t_data_nents_orig;
void *t_data_vmap;
struct scatterlist *t_bidi_data_sg;
unsigned int t_bidi_data_nents;