scsi: sd: Fix capacity calculation with 32-bit sector_t

[pandora-kernel.git] / drivers / scsi / sd.c

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 9a4f52d..6cbe2eb 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1051,18 +1051,19 @@ static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
        struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
        struct scsi_device *sdp = sdkp->device;
        struct Scsi_Host *host = sdp->host;
+       sector_t capacity = logical_to_sectors(sdp, sdkp->capacity);
        int diskinfo[4];
 
        /* default to most commonly used values */
-        diskinfo[0] = 0x40;    /* 1 << 6 */
-               diskinfo[1] = 0x20;     /* 1 << 5 */
-               diskinfo[2] = sdkp->capacity >> 11;
-       
+       diskinfo[0] = 0x40;     /* 1 << 6 */
+       diskinfo[1] = 0x20;     /* 1 << 5 */
+       diskinfo[2] = capacity >> 11;
+
        /* override with calculated, extended default, or driver values */
        if (host->hostt->bios_param)
-               host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
+               host->hostt->bios_param(sdp, bdev, capacity, diskinfo);
        else
-               scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
+               scsicam_bios_param(bdev, capacity, diskinfo);
 
        geo->heads = diskinfo[0];
        geo->sectors = diskinfo[1];
@@ -1647,6 +1648,22 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
 
 #define READ_CAPACITY_RETRIES_ON_RESET 10
 
+/*
+ * Ensure that we don't overflow sector_t when CONFIG_LBDAF is not set
+ * and the reported logical block size is bigger than 512 bytes. Note
+ * that last_sector is a u64 and therefore logical_to_sectors() is not
+ * applicable.
+ */
+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)
 {
@@ -1709,7 +1726,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
 
        sd_read_protection_type(sdkp, buffer);
 
-       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");
@@ -1795,7 +1812,7 @@ 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");
@@ -1931,14 +1948,6 @@ got_data:
                }
        }
 
-       /* Rescale capacity to 512-byte units */
-       if (sector_size == 4096)
-               sdkp->capacity <<= 3;
-       else if (sector_size == 2048)
-               sdkp->capacity <<= 2;
-       else if (sector_size == 1024)
-               sdkp->capacity <<= 1;
-
        blk_queue_physical_block_size(sdp->request_queue,
                                      sdkp->physical_block_size);
        sdkp->device->sector_size = sector_size;
@@ -2416,7 +2425,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 
        blk_queue_flush(sdkp->disk->queue, flush);
 
-       set_capacity(disk, sdkp->capacity);
+       set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity));
        kfree(buffer);
 
  out: