From: "Martin K. Petersen" <martin.petersen@oracle.com>
Date: Thu, 25 May 2017 09:34:30 -0400
Subject: [PATCH] scsi: sd: Use sysfs_match_string()
References: bsc#1061782
Git-commit: 4c11712ad0e1aa38154854a2a3efb1f4a90a059d
Patch-Mainline: v4.13-rc1
Avoid unnecessary snprintf() when formatting variables for display in
sysfs and switch to sysfs_match_string() for validating user input.
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/scsi/sd.c | 71 +++++++++++++++++++++++--------------------------------
1 file changed, 29 insertions(+), 42 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 53b6d72..7dc8cb8 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -155,7 +155,7 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
}
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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 @@ static void sd_set_flush_flag(struct scsi_disk *sdkp)
{
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);
--
1.8.5.6