* [PATCH] scsi: sd: Use sysfs_match_string()
@ 2017-05-26 17:02 Martin K. Petersen
2017-05-26 21:09 ` Bart Van Assche
0 siblings, 1 reply; 2+ messages in thread
From: Martin K. Petersen @ 2017-05-26 17:02 UTC (permalink / raw)
To: linux-scsi; +Cc: Martin K. Petersen
Avoid unnecessary snprintf() when formatting variables for display in
sysfs and switch to sysfs_match_string() for validating user input.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/sd.c | 71 ++++++++++++++++++++-----------------------------------
1 file changed, 26 insertions(+), 45 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index f9d1432d7cc5..aaf5cd7e4e6f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -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 = -1, 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);
@@ -362,7 +356,7 @@ 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);
@@ -381,7 +375,7 @@ 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
@@ -389,7 +383,7 @@ provisioning_mode_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct scsi_disk *sdkp = to_scsi_disk(dev);
- struct scsi_device *sdp = sdkp->device;
+ int mode;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
@@ -399,21 +393,11 @@ provisioning_mode_store(struct device *dev, struct device_attribute *attr,
return count;
}
- if (sdp->type != TYPE_DISK)
+ mode = sysfs_match_string(lbp_mode, buf);
+ if (mode < 0)
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
- return -EINVAL;
+ sd_config_discard(sdkp, mode);
return count;
}
@@ -432,7 +416,7 @@ 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 +424,17 @@ 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 +445,7 @@ 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 +471,7 @@ 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 +676,7 @@ 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);
--
2.13.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] scsi: sd: Use sysfs_match_string()
2017-05-26 17:02 [PATCH] scsi: sd: Use sysfs_match_string() Martin K. Petersen
@ 2017-05-26 21:09 ` Bart Van Assche
0 siblings, 0 replies; 2+ messages in thread
From: Bart Van Assche @ 2017-05-26 21:09 UTC (permalink / raw)
To: linux-scsi@vger.kernel.org, martin.petersen@oracle.com
On Fri, 2017-05-26 at 13:02 -0400, Martin K. Petersen wrote:
> Avoid unnecessary snprintf() when formatting variables for display in
> sysfs and switch to sysfs_match_string() for validating user input.
Hello Martin,
Would it be worth it to split this patch into two patches - one for the
snprintf() conversion and another patch for the sysfs_match_string()
conversion?
> @@ -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 = -1, rcd, wce, sp;
Is it still necessary to initialize ct in this function?
> + mode = sysfs_match_string(lbp_mode, buf);
> + if (mode < 0)
> return -EINVAL;
> [ ... ]
> + mode = sysfs_match_string(zeroing_mode, buf);
> + if (mode < 0)
> return -EINVAL;
sysfs_match_string() only supports dense arrays. Maybe it's worth to add a
comment above lbp_mode[] and zeroing_mode[] that these must be dense arrays
or that the above calls to sysfs_match_string() will break?
Otherwise this patch looks fine to me.
Bart.
^ permalink raw reply [flat|nested] 2+ messages in thread
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