Since snprintf() has the documented, but still rather strange trait of returning the length of the data that *would have been* written to the array if space were available, rather than the arguably more useful length of data *actually* written, it is usually considered wise to use something else instead in order to avoid confusion.
In the case of sysfs call-backs, new wrappers exist that do just that. Link: https://lwn.net/Articles/69419/ Link: https://github.com/KSPP/linux/issues/105 Signed-off-by: Lee Jones <l...@kernel.org> --- Cc: Adaptec OEM Raid Solutions <aacr...@microsemi.com> Cc: "James E.J. Bottomley" <j...@linux.ibm.com> Cc: "Martin K. Petersen" <martin.peter...@oracle.com> Cc: "PMC-Sierra, Inc" <aacr...@pmc-sierra.com> Cc: linux-s...@vger.kernel.org --- drivers/scsi/aacraid/linit.c | 34 ++++++++++++++-------------------- 1 file changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c index 68f4dbcfff492..69526e2bd2e78 100644 --- a/drivers/scsi/aacraid/linit.c +++ b/drivers/scsi/aacraid/linit.c @@ -558,11 +558,9 @@ static ssize_t aac_show_raid_level(struct device *dev, struct device_attribute * struct scsi_device *sdev = to_scsi_device(dev); struct aac_dev *aac = (struct aac_dev *)(sdev->host->hostdata); if (sdev_channel(sdev) != CONTAINER_CHANNEL) - return snprintf(buf, PAGE_SIZE, sdev->no_uld_attach - ? "Hidden\n" : + return sysfs_emit(buf, sdev->no_uld_attach ? "Hidden\n" : ((aac->jbod && (sdev->type == TYPE_DISK)) ? "JBOD\n" : "")); - return snprintf(buf, PAGE_SIZE, "%s\n", - get_container_type(aac->fsa_dev[sdev_id(sdev)].type)); + return sysfs_emit(buf, "%s\n", get_container_type(aac->fsa_dev[sdev_id(sdev)].type)); } static struct device_attribute aac_raid_level_attr = { @@ -1195,10 +1193,9 @@ static ssize_t aac_show_model(struct device *device, ++cp; while (*cp == ' ') ++cp; - len = snprintf(buf, PAGE_SIZE, "%s\n", cp); + len = sysfs_emit(buf, "%s\n", cp); } else - len = snprintf(buf, PAGE_SIZE, "%s\n", - aac_drivers[dev->cardtype].model); + len = sysfs_emit(buf, "%s\n", aac_drivers[dev->cardtype].model); return len; } @@ -1214,12 +1211,11 @@ static ssize_t aac_show_vendor(struct device *device, char *cp = sup_adap_info->adapter_type_text; while (*cp && *cp != ' ') ++cp; - len = snprintf(buf, PAGE_SIZE, "%.*s\n", + len = sysfs_emit(buf, "%.*s\n", (int)(cp - (char *)sup_adap_info->adapter_type_text), sup_adap_info->adapter_type_text); } else - len = snprintf(buf, PAGE_SIZE, "%s\n", - aac_drivers[dev->cardtype].vname); + len = sysfs_emit(buf, "%s\n", aac_drivers[dev->cardtype].vname); return len; } @@ -1230,7 +1226,7 @@ static ssize_t aac_show_flags(struct device *cdev, struct aac_dev *dev = (struct aac_dev*)class_to_shost(cdev)->hostdata; if (nblank(dprintk(x))) - len = snprintf(buf, PAGE_SIZE, "dprintk\n"); + len = sysfs_emit(buf, "dprintk\n"); #ifdef AAC_DETAILED_STATUS_INFO len += scnprintf(buf + len, PAGE_SIZE - len, "AAC_DETAILED_STATUS_INFO\n"); @@ -1258,7 +1254,7 @@ static ssize_t aac_show_kernel_version(struct device *device, int len, tmp; tmp = le32_to_cpu(dev->adapter_info.kernelrev); - len = snprintf(buf, PAGE_SIZE, "%d.%d-%d[%d]\n", + len = sysfs_emit(buf, "%d.%d-%d[%d]\n", tmp >> 24, (tmp >> 16) & 0xff, tmp & 0xff, le32_to_cpu(dev->adapter_info.kernelbuild)); return len; @@ -1272,7 +1268,7 @@ static ssize_t aac_show_monitor_version(struct device *device, int len, tmp; tmp = le32_to_cpu(dev->adapter_info.monitorrev); - len = snprintf(buf, PAGE_SIZE, "%d.%d-%d[%d]\n", + len = sysfs_emit(buf, "%d.%d-%d[%d]\n", tmp >> 24, (tmp >> 16) & 0xff, tmp & 0xff, le32_to_cpu(dev->adapter_info.monitorbuild)); return len; @@ -1286,7 +1282,7 @@ static ssize_t aac_show_bios_version(struct device *device, int len, tmp; tmp = le32_to_cpu(dev->adapter_info.biosrev); - len = snprintf(buf, PAGE_SIZE, "%d.%d-%d[%d]\n", + len = sysfs_emit(buf, "%d.%d-%d[%d]\n", tmp >> 24, (tmp >> 16) & 0xff, tmp & 0xff, le32_to_cpu(dev->adapter_info.biosbuild)); return len; @@ -1296,7 +1292,7 @@ static ssize_t aac_show_driver_version(struct device *device, struct device_attribute *attr, char *buf) { - return snprintf(buf, PAGE_SIZE, "%s\n", aac_driver_version); + return sysfs_emit(buf, "%s\n", aac_driver_version); } static ssize_t aac_show_serial_number(struct device *device, @@ -1322,15 +1318,13 @@ static ssize_t aac_show_serial_number(struct device *device, static ssize_t aac_show_max_channel(struct device *device, struct device_attribute *attr, char *buf) { - return snprintf(buf, PAGE_SIZE, "%d\n", - class_to_shost(device)->max_channel); + return sysfs_emit(buf, "%d\n", class_to_shost(device)->max_channel); } static ssize_t aac_show_max_id(struct device *device, struct device_attribute *attr, char *buf) { - return snprintf(buf, PAGE_SIZE, "%d\n", - class_to_shost(device)->max_id); + return sysfs_emit(buf, "%d\n", class_to_shost(device)->max_id); } static ssize_t aac_store_reset_adapter(struct device *device, @@ -1360,7 +1354,7 @@ static ssize_t aac_show_reset_adapter(struct device *device, tmp = aac_adapter_check_health(dev); if ((tmp == 0) && dev->in_reset) tmp = -EBUSY; - len = snprintf(buf, PAGE_SIZE, "0x%x\n", tmp); + len = sysfs_emit(buf, "0x%x\n", tmp); return len; } -- 2.43.0.594.gd9cf4e227d-goog
