Bart Van Assche <Bart.VanAssche@xxxxxxxxxxx> writes: Hi Bart, > Sorry but I still don't understand why the two checks are > different. How about the (untested) patch below? The approach below > avoids that the check is duplicated and - at least in my opinion - > results in code that is easier to read. Just tripped over this issue in connection with something else. However, I had to make a few passes to convince myself that your proposed fix was correct. How about something like the following? Martin diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index fb9b4d29af0b..6084c415c070 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2102,6 +2102,16 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp, #define READ_CAPACITY_RETRIES_ON_RESET 10 +static bool sd_addressable_capacity(u64 lba, unsigned int sector_size) +{ + u64 last_sector = lba + 1ULL << ilog2(sector_size) - 9; + + if (sizeof(sector_t) == 4 && last_sector > 0xffffffffULL) + return false; + + return true; +} + static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, unsigned char *buffer) { @@ -2167,7 +2177,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, return -ENODEV; } - if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) { + if (!sd_addressable_capacity(lba, sector_size)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " "devices.\n"); @@ -2256,7 +2266,7 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp, return sector_size; } - if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) { + if (!sd_addressable_capacity(lba, sector_size)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " "devices.\n");