scsi: ufs: core: Handle sentinel value for dHIDAvailableSize

JEDEC UFS spec defines 0xFFFFFFFF for dHIDAvailableSize as indicating no
valid fragmented size information. Returning the raw value can mislead
userspace. Return -ENODATA instead when the value is unavailable.

Signed-off-by: Keoseong Park <keosung.park@samsung.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251226042825epcms2p6f02ba12fa97ff4a69c00f6fb9ff55603@epcms2p6
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index b33f8656edb53a45081434738eca577d3fd08c2b..1017dd3ae5d3a38749e84c0132acc22afcd421e4 100644 (file)
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -1847,6 +1847,7 @@ static ssize_t defrag_trigger_store(struct device *dev,
 
 static DEVICE_ATTR_WO(defrag_trigger);
 
+#define UFS_HID_AVAILABLE_SIZE_INVALID 0xFFFFFFFFU
 static ssize_t fragmented_size_show(struct device *dev,
                struct device_attribute *attr, char *buf)
 {
@@ -1859,6 +1860,9 @@ static ssize_t fragmented_size_show(struct device *dev,
        if (ret)
                return ret;
 
+       if (value == UFS_HID_AVAILABLE_SIZE_INVALID)
+               return -ENODATA;
+
        return sysfs_emit(buf, "%u\n", value);
 }