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tcmu: Skip Data-Out blocks before gathering Data-In buffer for BIDI case 

For the bidirectional case, the Data-Out buffer blocks will always at
the head of the tcmu_cmd's bitmap, and before gathering the Data-In
buffer, first of all it should skip the Data-Out ones, or the device
supporting BIDI commands won't work.

Fixed: 26418649ee ("target/user: Introduce data_bitmap, replace
		data_length/data_head/data_tail")
Reported-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Tested-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Xiubo Li 2017-03-31 10:35:25 +08:00 committed by Nicholas Bellinger
parent 1c99de981f
commit a5d68ba858
1 changed files with 33 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
drivers/target/target_core_user.c
View File

@ -311,24 +311,50 @@ static void free_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd)
DATA_BLOCK_BITS); DATA_BLOCK_BITS);
} }
static void gather_data_area(struct tcmu_dev *udev, unsigned long *cmd_bitmap, static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
struct scatterlist *data_sg, unsigned int data_nents) bool bidi)
{ {
struct se_cmd *se_cmd = cmd->se_cmd;
int i, block; int i, block;
int block_remaining = 0; int block_remaining = 0;
void *from, *to; void *from, *to;
size_t copy_bytes, from_offset; size_t copy_bytes, from_offset;
struct scatterlist *sg; struct scatterlist *sg, *data_sg;
unsigned int data_nents;
DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS);
bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS);
if (!bidi) {
data_sg = se_cmd->t_data_sg;
data_nents = se_cmd->t_data_nents;
} else {
uint32_t count;
/*
* For bidi case, the first count blocks are for Data-Out
* buffer blocks, and before gathering the Data-In buffer
* the Data-Out buffer blocks should be discarded.
*/
count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
while (count--) {
block = find_first_bit(bitmap, DATA_BLOCK_BITS);
clear_bit(block, bitmap);
}
data_sg = se_cmd->t_bidi_data_sg;
data_nents = se_cmd->t_bidi_data_nents;
}
for_each_sg(data_sg, sg, data_nents, i) { for_each_sg(data_sg, sg, data_nents, i) {
int sg_remaining = sg->length; int sg_remaining = sg->length;
to = kmap_atomic(sg_page(sg)) + sg->offset; to = kmap_atomic(sg_page(sg)) + sg->offset;
while (sg_remaining > 0) { while (sg_remaining > 0) {
if (block_remaining == 0) { if (block_remaining == 0) {
block = find_first_bit(cmd_bitmap, block = find_first_bit(bitmap,
DATA_BLOCK_BITS); DATA_BLOCK_BITS);
block_remaining = DATA_BLOCK_SIZE; block_remaining = DATA_BLOCK_SIZE;
clear_bit(block, cmd_bitmap); clear_bit(block, bitmap);
} }
copy_bytes = min_t(size_t, sg_remaining, copy_bytes = min_t(size_t, sg_remaining,
block_remaining); block_remaining);
@ -610,19 +636,11 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
se_cmd->scsi_sense_length); se_cmd->scsi_sense_length);
free_data_area(udev, cmd); free_data_area(udev, cmd);
} else if (se_cmd->se_cmd_flags & SCF_BIDI) { } else if (se_cmd->se_cmd_flags & SCF_BIDI) {
DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS);
/* Get Data-In buffer before clean up */ /* Get Data-In buffer before clean up */
bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); gather_data_area(udev, cmd, true);
gather_data_area(udev, bitmap,
se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents);
free_data_area(udev, cmd); free_data_area(udev, cmd);
} else if (se_cmd->data_direction == DMA_FROM_DEVICE) { } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); gather_data_area(udev, cmd, false);
bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS);
gather_data_area(udev, bitmap,
se_cmd->t_data_sg, se_cmd->t_data_nents);
free_data_area(udev, cmd); free_data_area(udev, cmd);
} else if (se_cmd->data_direction == DMA_TO_DEVICE) { } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
free_data_area(udev, cmd); free_data_area(udev, cmd);