lkml.org 
[lkml]   [2010]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 03/97] SCSI: st: fix mdata->page_order handling
Date
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

commit c982c368bb90adbd312faa05d0cfd842e9ab45a7 upstream.

dio transfer always resets mdata->page_order to zero. It breaks
high-order pages previously allocated for non-dio transfer.

This patches adds reserved_page_order to st_buffer structure to save
page order for non-dio transfer.

http://bugzilla.kernel.org/show_bug.cgi?id=14563

When enlarge_buffer() allocates 524288 from 0, st uses six-order page
allocation. So mdata->page_order is 6 and frp_seg is 2.

After that, if st uses dio, sgl_map_user_pages() sets
mdata->page_order to 0 for st_do_scsi(). After that, when we call
normalize_buffer(), it frees only free frp_seg * PAGE_SIZE (2 * 4096)
though we should free frp_seg * PAGE_SIZE << 6 (2 * 4096 << 6). So we
see buffer_size is set to 516096 (524288 - 8192).

Reported-by: Joachim Breuer <linux-kernel@jmbreuer.net>
Tested-by: Joachim Breuer <linux-kernel@jmbreuer.net>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/scsi/st.c | 23 ++++++++++++-----------
drivers/scsi/st.h | 1 +
2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 12d58a7..5081f97 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -552,13 +552,15 @@ st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd
SRpnt->waiting = waiting;

if (STp->buffer->do_dio) {
+ mdata->page_order = 0;
mdata->nr_entries = STp->buffer->sg_segs;
mdata->pages = STp->buffer->mapped_pages;
} else {
+ mdata->page_order = STp->buffer->reserved_page_order;
mdata->nr_entries =
DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
- STp->buffer->map_data.pages = STp->buffer->reserved_pages;
- STp->buffer->map_data.offset = 0;
+ mdata->pages = STp->buffer->reserved_pages;
+ mdata->offset = 0;
}

memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
@@ -3718,7 +3720,7 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm
priority |= __GFP_ZERO;

if (STbuffer->frp_segs) {
- order = STbuffer->map_data.page_order;
+ order = STbuffer->reserved_page_order;
b_size = PAGE_SIZE << order;
} else {
for (b_size = PAGE_SIZE, order = 0;
@@ -3751,7 +3753,7 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm
segs++;
}
STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
- STbuffer->map_data.page_order = order;
+ STbuffer->reserved_page_order = order;

return 1;
}
@@ -3764,7 +3766,7 @@ static void clear_buffer(struct st_buffer * st_bp)

for (i=0; i < st_bp->frp_segs; i++)
memset(page_address(st_bp->reserved_pages[i]), 0,
- PAGE_SIZE << st_bp->map_data.page_order);
+ PAGE_SIZE << st_bp->reserved_page_order);
st_bp->cleared = 1;
}

@@ -3772,7 +3774,7 @@ static void clear_buffer(struct st_buffer * st_bp)
/* Release the extra buffer */
static void normalize_buffer(struct st_buffer * STbuffer)
{
- int i, order = STbuffer->map_data.page_order;
+ int i, order = STbuffer->reserved_page_order;

for (i = 0; i < STbuffer->frp_segs; i++) {
__free_pages(STbuffer->reserved_pages[i], order);
@@ -3780,7 +3782,7 @@ static void normalize_buffer(struct st_buffer * STbuffer)
}
STbuffer->frp_segs = 0;
STbuffer->sg_segs = 0;
- STbuffer->map_data.page_order = 0;
+ STbuffer->reserved_page_order = 0;
STbuffer->map_data.offset = 0;
}

@@ -3790,7 +3792,7 @@ static void normalize_buffer(struct st_buffer * STbuffer)
static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
{
int i, cnt, res, offset;
- int length = PAGE_SIZE << st_bp->map_data.page_order;
+ int length = PAGE_SIZE << st_bp->reserved_page_order;

for (i = 0, offset = st_bp->buffer_bytes;
i < st_bp->frp_segs && offset >= length; i++)
@@ -3822,7 +3824,7 @@ static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, in
static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
{
int i, cnt, res, offset;
- int length = PAGE_SIZE << st_bp->map_data.page_order;
+ int length = PAGE_SIZE << st_bp->reserved_page_order;

for (i = 0, offset = st_bp->read_pointer;
i < st_bp->frp_segs && offset >= length; i++)
@@ -3855,7 +3857,7 @@ static void move_buffer_data(struct st_buffer * st_bp, int offset)
{
int src_seg, dst_seg, src_offset = 0, dst_offset;
int count, total;
- int length = PAGE_SIZE << st_bp->map_data.page_order;
+ int length = PAGE_SIZE << st_bp->reserved_page_order;

if (offset == 0)
return;
@@ -4577,7 +4579,6 @@ static int sgl_map_user_pages(struct st_buffer *STbp,
}

mdata->offset = uaddr & ~PAGE_MASK;
- mdata->page_order = 0;
STbp->mapped_pages = pages;

return nr_pages;
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index 544dc6b..f91a67c 100644
--- a/drivers/scsi/st.h
+++ b/drivers/scsi/st.h
@@ -46,6 +46,7 @@ struct st_buffer {
struct st_request *last_SRpnt;
struct st_cmdstatus cmdstat;
struct page **reserved_pages;
+ int reserved_page_order;
struct page **mapped_pages;
struct rq_map_data map_data;
unsigned char *b_data;
--
1.6.6


\
 
 \ /
  Last update: 2010-01-05 02:01    [W:0.483 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site