Commit 4c11712a authored by Martin K. Petersen's avatar Martin K. Petersen
Browse files

scsi: sd: Use sysfs_match_string() 



Avoid unnecessary snprintf() when formatting variables for display in
sysfs and switch to sysfs_match_string() for validating user input.

Reviewed-by: default avatarBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 6934be4f

drivers/scsi/sd.c

+29 −42
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ static ssize_t 
cache_type_store(struct device *dev, struct device_attribute *attr,

		 const char *buf, size_t count)

{

	int i, ct = -1, rcd, wce, sp;

	int ct, rcd, wce, sp;

	struct scsi_disk *sdkp = to_scsi_disk(dev);

	struct scsi_device *sdp = sdkp->device;

	char buffer[64];
@@ -178,16 +178,10 @@ cache_type_store(struct device *dev, struct device_attribute *attr, 
		sdkp->cache_override = 0;

	}



	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {

		len = strlen(sd_cache_types[i]);

		if (strncmp(sd_cache_types[i], buf, len) == 0 &&

		    buf[len] == '\n') {

			ct = i;

			break;

		}

	}

	ct = sysfs_match_string(sd_cache_types, buf);

	if (ct < 0)

		return -EINVAL;



	rcd = ct & 0x01 ? 1 : 0;

	wce = (ct & 0x02) && !sdkp->write_prot ? 1 : 0;
@@ -227,7 +221,7 @@ manage_start_stop_show(struct device *dev, struct device_attribute *attr, 
	struct scsi_disk *sdkp = to_scsi_disk(dev);

	struct scsi_device *sdp = sdkp->device;



	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);

	return sprintf(buf, "%u\n", sdp->manage_start_stop);

}



static ssize_t
@@ -251,7 +245,7 @@ allow_restart_show(struct device *dev, struct device_attribute *attr, char *buf) 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);

	return sprintf(buf, "%u\n", sdkp->device->allow_restart);

}



static ssize_t
@@ -279,7 +273,7 @@ cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 
	struct scsi_disk *sdkp = to_scsi_disk(dev);

	int ct = sdkp->RCD + 2*sdkp->WCE;



	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);

	return sprintf(buf, "%s\n", sd_cache_types[ct]);

}

static DEVICE_ATTR_RW(cache_type);
@@ -288,7 +282,7 @@ FUA_show(struct device *dev, struct device_attribute *attr, char *buf) 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);

	return sprintf(buf, "%u\n", sdkp->DPOFUA);

}

static DEVICE_ATTR_RO(FUA);
@@ -298,7 +292,7 @@ protection_type_show(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->protection_type);

	return sprintf(buf, "%u\n", sdkp->protection_type);

}



static ssize_t
@@ -341,9 +335,9 @@ protection_mode_show(struct device *dev, struct device_attribute *attr, 
	}



	if (!dif && !dix)

		return snprintf(buf, 20, "none\n");

		return sprintf(buf, "none\n");



	return snprintf(buf, 20, "%s%u\n", dix ? "dix" : "dif", dif);

	return sprintf(buf, "%s%u\n", dix ? "dix" : "dif", dif);

}

static DEVICE_ATTR_RO(protection_mode);
@@ -352,7 +346,7 @@ app_tag_own_show(struct device *dev, struct device_attribute *attr, char *buf) 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->ATO);

	return sprintf(buf, "%u\n", sdkp->ATO);

}

static DEVICE_ATTR_RO(app_tag_own);
@@ -362,10 +356,11 @@ thin_provisioning_show(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->lbpme);

	return sprintf(buf, "%u\n", sdkp->lbpme);

}

static DEVICE_ATTR_RO(thin_provisioning);



/* sysfs_match_string() requires dense arrays */

static const char *lbp_mode[] = {

	[SD_LBP_FULL]		= "full",

	[SD_LBP_UNMAP]		= "unmap",
@@ -381,7 +376,7 @@ provisioning_mode_show(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%s\n", lbp_mode[sdkp->provisioning_mode]);

	return sprintf(buf, "%s\n", lbp_mode[sdkp->provisioning_mode]);

}



static ssize_t
@@ -390,6 +385,7 @@ provisioning_mode_store(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);

	struct scsi_device *sdp = sdkp->device;

	int mode;



	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;
@@ -402,23 +398,17 @@ provisioning_mode_store(struct device *dev, struct device_attribute *attr, 
	if (sdp->type != TYPE_DISK)

		return -EINVAL;



	if (!strncmp(buf, lbp_mode[SD_LBP_UNMAP], 20))

		sd_config_discard(sdkp, SD_LBP_UNMAP);

	else if (!strncmp(buf, lbp_mode[SD_LBP_WS16], 20))

		sd_config_discard(sdkp, SD_LBP_WS16);

	else if (!strncmp(buf, lbp_mode[SD_LBP_WS10], 20))

		sd_config_discard(sdkp, SD_LBP_WS10);

	else if (!strncmp(buf, lbp_mode[SD_LBP_ZERO], 20))

		sd_config_discard(sdkp, SD_LBP_ZERO);

	else if (!strncmp(buf, lbp_mode[SD_LBP_DISABLE], 20))

		sd_config_discard(sdkp, SD_LBP_DISABLE);

	else

	mode = sysfs_match_string(lbp_mode, buf);

	if (mode < 0)

		return -EINVAL;



	sd_config_discard(sdkp, mode);



	return count;

}

static DEVICE_ATTR_RW(provisioning_mode);



/* sysfs_match_string() requires dense arrays */

static const char *zeroing_mode[] = {

	[SD_ZERO_WRITE]		= "write",

	[SD_ZERO_WS]		= "writesame",
@@ -432,7 +422,7 @@ zeroing_mode_show(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%s\n", zeroing_mode[sdkp->zeroing_mode]);

	return sprintf(buf, "%s\n", zeroing_mode[sdkp->zeroing_mode]);

}



static ssize_t
@@ -440,21 +430,17 @@ zeroing_mode_store(struct device *dev, struct device_attribute *attr, 
		   const char *buf, size_t count)

{

	struct scsi_disk *sdkp = to_scsi_disk(dev);

	int mode;



	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;



	if (!strncmp(buf, zeroing_mode[SD_ZERO_WRITE], 20))

		sdkp->zeroing_mode = SD_ZERO_WRITE;

	else if (!strncmp(buf, zeroing_mode[SD_ZERO_WS], 20))

		sdkp->zeroing_mode = SD_ZERO_WS;

	else if (!strncmp(buf, zeroing_mode[SD_ZERO_WS16_UNMAP], 20))

		sdkp->zeroing_mode = SD_ZERO_WS16_UNMAP;

	else if (!strncmp(buf, zeroing_mode[SD_ZERO_WS10_UNMAP], 20))

		sdkp->zeroing_mode = SD_ZERO_WS10_UNMAP;

	else

	mode = sysfs_match_string(zeroing_mode, buf);

	if (mode < 0)

		return -EINVAL;



	sdkp->zeroing_mode = mode;



	return count;

}

static DEVICE_ATTR_RW(zeroing_mode);
@@ -465,7 +451,7 @@ max_medium_access_timeouts_show(struct device *dev, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->max_medium_access_timeouts);

	return sprintf(buf, "%u\n", sdkp->max_medium_access_timeouts);

}



static ssize_t
@@ -491,7 +477,7 @@ max_write_same_blocks_show(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->max_ws_blocks);

	return sprintf(buf, "%u\n", sdkp->max_ws_blocks);

}



static ssize_t
@@ -696,6 +682,7 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode) 


	switch (mode) {



	case SD_LBP_FULL:

	case SD_LBP_DISABLE:

		blk_queue_max_discard_sectors(q, 0);

		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);