* [PATCH 2/3] [SCSI] sd: remove dead code
2011-08-02 3:50 [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn Namhyung Kim
@ 2011-08-02 3:50 ` Namhyung Kim
2011-08-02 16:29 ` James Bottomley
2011-08-02 3:50 ` [PATCH 3/3] [SCSI] sd: update kernel doc comments Namhyung Kim
2011-08-02 16:29 ` [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn James Bottomley
2 siblings, 1 reply; 6+ messages in thread
From: Namhyung Kim @ 2011-08-02 3:50 UTC (permalink / raw)
To: James E.J. Bottomley; +Cc: linux-scsi, linux-kernel
As rq_data_dir() only checks a single bit (REQ_WRITE), the result
can not be anything but READ or WRITE. Thus last ELSE clause is
not needed at all.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
drivers/scsi/sd.c | 5 +----
1 files changed, 1 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 463a324835f4..fbb522add124 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -760,12 +760,9 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
goto out;
- } else if (rq_data_dir(rq) == READ) {
+ } else { /* READ */
SCpnt->cmnd[0] = READ_6;
SCpnt->sc_data_direction = DMA_FROM_DEVICE;
- } else {
- scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
- goto out;
}
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
--
1.7.6
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 2/3] [SCSI] sd: remove dead code
2011-08-02 3:50 ` [PATCH 2/3] [SCSI] sd: remove dead code Namhyung Kim
@ 2011-08-02 16:29 ` James Bottomley
0 siblings, 0 replies; 6+ messages in thread
From: James Bottomley @ 2011-08-02 16:29 UTC (permalink / raw)
To: Namhyung Kim; +Cc: linux-scsi, linux-kernel
On Tue, 2011-08-02 at 12:50 +0900, Namhyung Kim wrote:
> As rq_data_dir() only checks a single bit (REQ_WRITE), the result
> can not be anything but READ or WRITE. Thus last ELSE clause is
> not needed at all.
This isn't really dead code, it's future proofing. Block can handle
bidirectional commands. It's true that currently the rq_data_dir()
macro is wrong for them. However, if anyone decided to fix it, we'd
need the check.
James
> Signed-off-by: Namhyung Kim <namhyung@gmail.com>
> ---
> drivers/scsi/sd.c | 5 +----
> 1 files changed, 1 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 463a324835f4..fbb522add124 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -760,12 +760,9 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
> sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
> goto out;
>
> - } else if (rq_data_dir(rq) == READ) {
> + } else { /* READ */
> SCpnt->cmnd[0] = READ_6;
> SCpnt->sc_data_direction = DMA_FROM_DEVICE;
> - } else {
> - scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
> - goto out;
> }
>
> SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 3/3] [SCSI] sd: update kernel doc comments
2011-08-02 3:50 [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn Namhyung Kim
2011-08-02 3:50 ` [PATCH 2/3] [SCSI] sd: remove dead code Namhyung Kim
@ 2011-08-02 3:50 ` Namhyung Kim
2011-08-02 16:29 ` [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn James Bottomley
2 siblings, 0 replies; 6+ messages in thread
From: Namhyung Kim @ 2011-08-02 3:50 UTC (permalink / raw)
To: James E.J. Bottomley; +Cc: linux-scsi, linux-kernel, Randy Dunlap
Fix a typo and update argument names.
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
drivers/scsi/sd.c | 31 +++++++++++++------------------
1 files changed, 13 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index fbb522add124..496a4d9ca670 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -529,7 +529,7 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
/**
* scsi_setup_discard_cmnd - unmap blocks on thinly provisioned device
- * @sdp: scsi device to operate one
+ * @sdp: scsi device to operate on
* @rq: Request to prepare
*
* Will issue either UNMAP or WRITE SAME(16) depending on preference
@@ -635,8 +635,8 @@ static void sd_unprep_fn(struct request_queue *q, struct request *rq)
/**
* sd_init_command - build a scsi (read or write) command from
* information in the request structure.
- * @SCpnt: pointer to mid-level's per scsi command structure that
- * contains request and into which the scsi command is written
+ * @q: pointer to request queue structure
+ * @rq: request to prepare
*
* Returns 1 if successful and 0 if error (or cannot be done now).
**/
@@ -890,17 +890,12 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
/**
* sd_open - open a scsi disk device
- * @inode: only i_rdev member may be used
- * @filp: only f_mode and f_flags may be used
+ * @bdev: block device to open
+ * @mode: file open mode
*
* Returns 0 if successful. Returns a negated errno value in case
* of error.
*
- * Note: This can be called from a user context (e.g. fsck(1) )
- * or from within the kernel (e.g. as a result of a mount(1) ).
- * In the latter case @inode and @filp carry an abridged amount
- * of information as noted above.
- *
* Locking: called with bdev->bd_mutex held.
**/
static int sd_open(struct block_device *bdev, fmode_t mode)
@@ -973,8 +968,8 @@ error_autopm:
/**
* sd_release - invoked when the (last) close(2) is called on this
* scsi disk.
- * @inode: only i_rdev member may be used
- * @filp: only f_mode and f_flags may be used
+ * @disk: generic disk structure
+ * @mode: file open mode
*
* Returns 0.
*
@@ -1031,8 +1026,8 @@ static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
/**
* sd_ioctl - process an ioctl
- * @inode: only i_rdev/i_bdev members may be used
- * @filp: only f_mode and f_flags may be used
+ * @bdev: block device to process
+ * @mode: file open mode
* @cmd: ioctl command number
* @arg: this is third argument given to ioctl(2) system call.
* Often contains a pointer.
@@ -2198,7 +2193,7 @@ static void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
/**
* sd_read_block_limits - Query disk device for preferred I/O sizes.
- * @disk: disk to query
+ * @sdkp: disk to query
*/
static void sd_read_block_limits(struct scsi_disk *sdkp)
{
@@ -2264,7 +2259,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
/**
* sd_read_block_characteristics - Query block dev. characteristics
- * @disk: disk to query
+ * @sdkp: disk to query
*/
static void sd_read_block_characteristics(struct scsi_disk *sdkp)
{
@@ -2290,7 +2285,7 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
/**
* sd_read_block_provisioning - Query provisioning VPD page
- * @disk: disk to query
+ * @sdkp: disk to query
*/
static void sd_read_block_provisioning(struct scsi_disk *sdkp)
{
@@ -2629,7 +2624,7 @@ static int sd_probe(struct device *dev)
* sd_remove - called whenever a scsi disk (previously recognized by
* sd_probe) is detached from the system. It is called (potentially
* multiple times) during sd module unload.
- * @sdp: pointer to mid level scsi device object
+ * @dev: pointer to device object
*
* Note: this function is invoked from the scsi mid-level.
* This function potentially frees up a device name (e.g. /dev/sdc)
--
1.7.6
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn
2011-08-02 3:50 [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn Namhyung Kim
2011-08-02 3:50 ` [PATCH 2/3] [SCSI] sd: remove dead code Namhyung Kim
2011-08-02 3:50 ` [PATCH 3/3] [SCSI] sd: update kernel doc comments Namhyung Kim
@ 2011-08-02 16:29 ` James Bottomley
2011-08-03 1:03 ` [PATCH v2] [SCSI] sd: consolidate sector size alignment check in sd_prep_fn Namhyung Kim
2 siblings, 1 reply; 6+ messages in thread
From: James Bottomley @ 2011-08-02 16:29 UTC (permalink / raw)
To: Namhyung Kim; +Cc: linux-scsi, linux-kernel
On Tue, 2011-08-02 at 12:50 +0900, Namhyung Kim wrote:
> Generalize common code to reduce code duplication.
This code isn't equivalent because it won't fail sector sizes > 4096
which we can't support.
Plus I really don't see much point doing this: ilog2 is a far less
efficient operation on several platforms and this is the hot path.
James
> Signed-off-by: Namhyung Kim <namhyung@gmail.com>
> ---
> drivers/scsi/sd.c | 32 ++++++++------------------------
> 1 files changed, 8 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 953773cb26d9..463a324835f4 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -735,36 +735,20 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
> * and not force the scsi disk driver to use bounce buffers
> * for this.
> */
> - if (sdp->sector_size == 1024) {
> - if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
> - scmd_printk(KERN_ERR, SCpnt,
> - "Bad block number requested\n");
> - goto out;
> - } else {
> - block = block >> 1;
> - this_count = this_count >> 1;
> - }
> - }
> - if (sdp->sector_size == 2048) {
> - if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
> - scmd_printk(KERN_ERR, SCpnt,
> - "Bad block number requested\n");
> - goto out;
> - } else {
> - block = block >> 2;
> - this_count = this_count >> 2;
> - }
> - }
> - if (sdp->sector_size == 4096) {
> - if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
> + if (sdp->sector_size > 512) {
> + int shift = ilog2(sdp->sector_size) - 9;
> +
> + if (!IS_ALIGNED(block, 1 << shift) ||
> + !IS_ALIGNED(blk_rq_sectors(rq), 1 << shift)) {
> scmd_printk(KERN_ERR, SCpnt,
> "Bad block number requested\n");
> goto out;
> } else {
> - block = block >> 3;
> - this_count = this_count >> 3;
> + block = block >> shift;
> + this_count = this_count >> shift;
> }
> }
> +
> if (rq_data_dir(rq) == WRITE) {
> if (!sdp->writeable) {
> goto out;
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v2] [SCSI] sd: consolidate sector size alignment check in sd_prep_fn
2011-08-02 16:29 ` [PATCH 1/3] [SCSI] sd: consolidate sector size alignment check in sd_pref_fn James Bottomley
@ 2011-08-03 1:03 ` Namhyung Kim
0 siblings, 0 replies; 6+ messages in thread
From: Namhyung Kim @ 2011-08-03 1:03 UTC (permalink / raw)
To: James Bottomley; +Cc: linux-scsi, linux-kernel
Generalize common code to reduce code duplication.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
drivers/scsi/sd.c | 36 ++++++++++++------------------------
1 files changed, 12 insertions(+), 24 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 953773cb26d9..fb9d997ece9d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -651,6 +651,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
unsigned int this_count = blk_rq_sectors(rq);
int ret, host_dif;
unsigned char protect;
+ int sector_shift;
/*
* Discard request come in as REQ_TYPE_FS but we turn them into
@@ -735,36 +736,23 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
* and not force the scsi disk driver to use bounce buffers
* for this.
*/
- if (sdp->sector_size == 1024) {
- if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
+ sector_shift = 0;
+ switch (sdp->sector_size) {
+ case 4096: sector_shift++; /* fall through */
+ case 2048: sector_shift++; /* fall through */
+ case 1024: sector_shift++;
+
+ if (!IS_ALIGNED(block, 1 << sector_shift) ||
+ !IS_ALIGNED(blk_rq_sectors(rq), 1 << sector_shift)) {
scmd_printk(KERN_ERR, SCpnt,
"Bad block number requested\n");
goto out;
} else {
- block = block >> 1;
- this_count = this_count >> 1;
- }
- }
- if (sdp->sector_size == 2048) {
- if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
- scmd_printk(KERN_ERR, SCpnt,
- "Bad block number requested\n");
- goto out;
- } else {
- block = block >> 2;
- this_count = this_count >> 2;
- }
- }
- if (sdp->sector_size == 4096) {
- if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
- scmd_printk(KERN_ERR, SCpnt,
- "Bad block number requested\n");
- goto out;
- } else {
- block = block >> 3;
- this_count = this_count >> 3;
+ block = block >> sector_shift;
+ this_count = this_count >> sector_shift;
}
}
+
if (rq_data_dir(rq) == WRITE) {
if (!sdp->writeable) {
goto out;
--
1.7.6
^ permalink raw reply related [flat|nested] 6+ messages in thread