target: Fix max_unmap_lba_count calc overflow
max_discard_sectors only 32bits, and some non scsi backend
devices will set this to the max 0xffffffff, so we can end up
overflowing during the max_unmap_lba_count calculation.
This fixes a regression caused by my patch:
commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3
Author: Mike Christie <mchristi@redhat.com>
Date: Mon Jan 18 14:09:27 2016 -0600
target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors
which can result in extra discards being sent to due the overflow
causing max_unmap_lba_count to be smaller than what the backing
device can actually support.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index a4046ca..6b42348 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -821,13 +821,15 @@
* in ATA and we need to set TPE=1
*/
bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
- struct request_queue *q, int block_size)
+ struct request_queue *q)
{
+ int block_size = queue_logical_block_size(q);
+
if (!blk_queue_discard(q))
return false;
- attrib->max_unmap_lba_count = (q->limits.max_discard_sectors << 9) /
- block_size;
+ attrib->max_unmap_lba_count =
+ q->limits.max_discard_sectors >> (ilog2(block_size) - 9);
/*
* Currently hardcoded to 1 in Linux/SCSI code..
*/
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 75f0f08..7929186 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -161,8 +161,7 @@
dev_size, div_u64(dev_size, fd_dev->fd_block_size),
fd_dev->fd_block_size);
- if (target_configure_unmap_from_queue(&dev->dev_attrib, q,
- fd_dev->fd_block_size))
+ if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
pr_debug("IFILE: BLOCK Discard support available,"
" disabled by default\n");
/*
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 7c4efb4..2077bc2 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -121,8 +121,7 @@
dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
dev->dev_attrib.hw_queue_depth = q->nr_requests;
- if (target_configure_unmap_from_queue(&dev->dev_attrib, q,
- dev->dev_attrib.hw_block_size))
+ if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
pr_debug("IBLOCK: BLOCK Discard support available,"
" disabled by default\n");
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index d8ab510..f6f3bc5 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -95,6 +95,6 @@
bool target_sense_desc_format(struct se_device *dev);
sector_t target_to_linux_sector(struct se_device *dev, sector_t lb);
bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
- struct request_queue *q, int block_size);
+ struct request_queue *q);
#endif /* TARGET_CORE_BACKEND_H */
