-Original Message-
From: devel [mailto:driverdev-devel-boun...@linuxdriverproject.org] On
Behalf Of K. Y. Srinivasan
Sent: Monday, March 23, 2015 2:07 PM
To: gre...@linuxfoundation.org; linux-ker...@vger.kernel.org;
de...@linuxdriverproject.org; oher...@suse.com; jbottom...@parallels.com;
h...@infradead.org; linux-scsi@vger.kernel.org; a...@canonical.com;
vkuzn...@redhat.com; jasow...@redhat.com
Subject: [PATCH 6/7] scsi: storvsc: Don't assume that the scatterlist is not
chained
The current code assumes that the scatterlists presented are not chained.
Fix the code to not make this assumption.
Signed-off-by: K. Y. Srinivasan k...@microsoft.com
Reviewed-by: Long Li lon...@microsoft.com
---
drivers/scsi/storvsc_drv.c | 98 +--
1 files changed, 57 insertions(+), 41 deletions(-)
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index
88f5d79..a599677 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -626,19 +626,6 @@ cleanup:
return NULL;
}
-/* Disgusting wrapper functions */
-static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
-{
- void *addr = kmap_atomic(sg_page(sgl + idx));
- return (unsigned long)addr;
-}
-
-static inline void sg_kunmap_atomic(unsigned long addr) -{
- kunmap_atomic((void *)addr);
-}
-
-
/* Assume the original sgl has enough room */ static unsigned int
copy_from_bounce_buffer(struct scatterlist *orig_sgl,
struct scatterlist *bounce_sgl, @@ -
653,32 +640,39 @@ static unsigned int copy_from_bounce_buffer(struct
scatterlist *orig_sgl,
unsigned long bounce_addr = 0;
unsigned long dest_addr = 0;
unsigned long flags;
+ struct scatterlist *cur_dest_sgl;
+ struct scatterlist *cur_src_sgl;
local_irq_save(flags);
-
+ cur_dest_sgl = orig_sgl;
+ cur_src_sgl = bounce_sgl;
for (i = 0; i orig_sgl_count; i++) {
- dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
+ dest_addr = (unsigned long)
+ kmap_atomic(sg_page(cur_dest_sgl)) +
+ cur_dest_sgl-offset;
dest = dest_addr;
destlen = orig_sgl[i].length;
+ destlen = cur_dest_sgl-length;
if (bounce_addr == 0)
- bounce_addr = sg_kmap_atomic(bounce_sgl,j);
+ bounce_addr = (unsigned long)kmap_atomic(
+ sg_page(cur_src_sgl));
while (destlen) {
- src = bounce_addr + bounce_sgl[j].offset;
- srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
+ src = bounce_addr + cur_src_sgl-offset;
+ srclen = cur_src_sgl-length - cur_src_sgl-offset;
copylen = min(srclen, destlen);
memcpy((void *)dest, (void *)src, copylen);
total_copied += copylen;
- bounce_sgl[j].offset += copylen;
+ cur_src_sgl-offset += copylen;
destlen -= copylen;
dest += copylen;
- if (bounce_sgl[j].offset == bounce_sgl[j].length) {
+ if (cur_src_sgl-offset == cur_src_sgl-length) {
/* full */
- sg_kunmap_atomic(bounce_addr);
+ kunmap_atomic((void *)bounce_addr);
j++;
/*
@@ -692,21 +686,27 @@ static unsigned int copy_from_bounce_buffer(struct
scatterlist *orig_sgl,
/*
* We are done; cleanup and return.
*/
- sg_kunmap_atomic(dest_addr -
orig_sgl[i].offset);
+ kunmap_atomic((void *)(dest_addr -
+ cur_dest_sgl-offset));
local_irq_restore(flags);
return total_copied;
}
/* if we need to use another bounce buffer */
- if (destlen || i != orig_sgl_count - 1)
- bounce_addr =
sg_kmap_atomic(bounce_sgl,j);
+ if (destlen || i != orig_sgl_count - 1) {
+ cur_src_sgl = sg_next(cur_src_sgl);
+ bounce_addr = (unsigned long)
+ kmap_atomic(
+ sg_page(cur_src_sgl));
+ }
