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[SCSI] sd: Refactor sd_read_capacity()
The sd_read_capacity() function was about 180 lines long and included a backwards goto and a tricky state variable. Splitting out read_capacity_10() and read_capacity_16() (about 50 lines each) reduces sd_read_capacity to about 100 lines and gets rid of the backwards goto and the state variable. I've tried to avoid any behaviour change with this patch. [jejb: upped transfer request to standard recommended 32 for RC16] Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Matthew Wilcox
James Bottomley
parent
635374e7eb
commit
0da205e01b
1 changed files with 158 additions and 89 deletions
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@ -1273,42 +1273,61 @@ void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
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sdkp->capacity = 0;
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}
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/*
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* read disk capacity
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*/
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static void
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sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
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static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
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struct scsi_sense_hdr *sshdr, int sense_valid,
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int the_result)
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{
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sd_print_result(sdkp, the_result);
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if (driver_byte(the_result) & DRIVER_SENSE)
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sd_print_sense_hdr(sdkp, sshdr);
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else
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sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
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/*
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* Set dirty bit for removable devices if not ready -
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* sometimes drives will not report this properly.
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*/
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if (sdp->removable &&
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sense_valid && sshdr->sense_key == NOT_READY)
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sdp->changed = 1;
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/*
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* We used to set media_present to 0 here to indicate no media
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* in the drive, but some drives fail read capacity even with
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* media present, so we can't do that.
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*/
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sdkp->capacity = 0; /* unknown mapped to zero - as usual */
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}
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#define RC16_LEN 32
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#if RC16_LEN > SD_BUF_SIZE
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#error RC16_LEN must not be more than SD_BUF_SIZE
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#endif
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static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
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unsigned char *buffer)
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{
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unsigned char cmd[16];
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int the_result, retries;
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int sector_size = 0;
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/* Force READ CAPACITY(16) when PROTECT=1 */
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int longrc = scsi_device_protection(sdkp->device) ? 1 : 0;
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struct scsi_sense_hdr sshdr;
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int sense_valid = 0;
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struct scsi_device *sdp = sdkp->device;
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int the_result;
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int retries = 3;
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unsigned long long lba;
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unsigned sector_size;
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repeat:
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retries = 3;
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do {
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if (longrc) {
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memset((void *) cmd, 0, 16);
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cmd[0] = SERVICE_ACTION_IN;
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cmd[1] = SAI_READ_CAPACITY_16;
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cmd[13] = 13;
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memset((void *) buffer, 0, 13);
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} else {
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cmd[0] = READ_CAPACITY;
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memset((void *) &cmd[1], 0, 9);
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memset((void *) buffer, 0, 8);
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}
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memset(cmd, 0, 16);
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cmd[0] = SERVICE_ACTION_IN;
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cmd[1] = SAI_READ_CAPACITY_16;
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cmd[13] = RC16_LEN;
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memset(buffer, 0, RC16_LEN);
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the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
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buffer, longrc ? 13 : 8, &sshdr,
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SD_TIMEOUT, SD_MAX_RETRIES, NULL);
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buffer, RC16_LEN, &sshdr,
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SD_TIMEOUT, SD_MAX_RETRIES, NULL);
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if (media_not_present(sdkp, &sshdr))
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return;
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return -ENODEV;
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if (the_result)
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sense_valid = scsi_sense_valid(&sshdr);
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@ -1316,72 +1335,122 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
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} while (the_result && retries);
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if (the_result && !longrc) {
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sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
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sd_print_result(sdkp, the_result);
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if (driver_byte(the_result) & DRIVER_SENSE)
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sd_print_sense_hdr(sdkp, &sshdr);
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else
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sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
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/* Set dirty bit for removable devices if not ready -
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* sometimes drives will not report this properly. */
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if (sdp->removable &&
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sense_valid && sshdr.sense_key == NOT_READY)
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sdp->changed = 1;
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/* Either no media are present but the drive didn't tell us,
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or they are present but the read capacity command fails */
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/* sdkp->media_present = 0; -- not always correct */
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sdkp->capacity = 0; /* unknown mapped to zero - as usual */
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return;
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} else if (the_result && longrc) {
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/* READ CAPACITY(16) has been failed */
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if (the_result) {
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sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
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sd_print_result(sdkp, the_result);
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sd_printk(KERN_NOTICE, sdkp, "Use 0xffffffff as device size\n");
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read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
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return -EINVAL;
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}
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sdkp->capacity = 1 + (sector_t) 0xffffffff;
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goto got_data;
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}
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if (!longrc) {
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sector_size = (buffer[4] << 24) |
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(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
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if (buffer[0] == 0xff && buffer[1] == 0xff &&
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buffer[2] == 0xff && buffer[3] == 0xff) {
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if(sizeof(sdkp->capacity) > 4) {
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sd_printk(KERN_NOTICE, sdkp, "Very big device. "
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"Trying to use READ CAPACITY(16).\n");
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longrc = 1;
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goto repeat;
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}
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sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use "
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"a kernel compiled with support for large "
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"block devices.\n");
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sdkp->capacity = 0;
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sector_size = (buffer[8] << 24) | (buffer[9] << 16) |
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(buffer[10] << 8) | buffer[11];
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lba = (((u64)buffer[0] << 56) | ((u64)buffer[1] << 48) |
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((u64)buffer[2] << 40) | ((u64)buffer[3] << 32) |
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((u64)buffer[4] << 24) | ((u64)buffer[5] << 16) |
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((u64)buffer[6] << 8) | (u64)buffer[7]);
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sd_read_protection_type(sdkp, buffer);
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if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
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sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
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"kernel compiled with support for large block "
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"devices.\n");
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sdkp->capacity = 0;
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return -EOVERFLOW;
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}
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sdkp->capacity = lba + 1;
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return sector_size;
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}
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static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
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unsigned char *buffer)
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{
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unsigned char cmd[16];
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struct scsi_sense_hdr sshdr;
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int sense_valid = 0;
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int the_result;
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int retries = 3;
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sector_t lba;
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unsigned sector_size;
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do {
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cmd[0] = READ_CAPACITY;
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memset(&cmd[1], 0, 9);
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memset(buffer, 0, 8);
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the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
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buffer, 8, &sshdr,
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SD_TIMEOUT, SD_MAX_RETRIES, NULL);
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if (media_not_present(sdkp, &sshdr))
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return -ENODEV;
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if (the_result)
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sense_valid = scsi_sense_valid(&sshdr);
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retries--;
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} while (the_result && retries);
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if (the_result) {
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sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
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read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
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return -EINVAL;
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}
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sector_size = (buffer[4] << 24) | (buffer[5] << 16) |
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(buffer[6] << 8) | buffer[7];
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lba = (buffer[0] << 24) | (buffer[1] << 16) |
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(buffer[2] << 8) | buffer[3];
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if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
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sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
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"kernel compiled with support for large block "
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"devices.\n");
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sdkp->capacity = 0;
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return -EOVERFLOW;
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}
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sdkp->capacity = lba + 1;
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return sector_size;
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}
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/*
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* read disk capacity
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*/
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static void
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sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
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{
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int sector_size;
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struct scsi_device *sdp = sdkp->device;
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/* Force READ CAPACITY(16) when PROTECT=1 */
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if (scsi_device_protection(sdp)) {
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sector_size = read_capacity_16(sdkp, sdp, buffer);
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if (sector_size == -EOVERFLOW)
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goto got_data;
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}
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sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
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(buffer[1] << 16) |
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(buffer[2] << 8) |
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buffer[3]);
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if (sector_size < 0)
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return;
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} else {
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sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
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((u64)buffer[1] << 48) |
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((u64)buffer[2] << 40) |
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((u64)buffer[3] << 32) |
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((sector_t)buffer[4] << 24) |
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((sector_t)buffer[5] << 16) |
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((sector_t)buffer[6] << 8) |
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(sector_t)buffer[7]);
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sector_size = (buffer[8] << 24) |
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(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
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sd_read_protection_type(sdkp, buffer);
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}
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sector_size = read_capacity_10(sdkp, sdp, buffer);
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if (sector_size == -EOVERFLOW)
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goto got_data;
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if (sector_size < 0)
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return;
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if ((sizeof(sdkp->capacity) > 4) &&
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(sdkp->capacity > 0xffffffffULL)) {
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int old_sector_size = sector_size;
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sd_printk(KERN_NOTICE, sdkp, "Very big device. "
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"Trying to use READ CAPACITY(16).\n");
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sector_size = read_capacity_16(sdkp, sdp, buffer);
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if (sector_size < 0) {
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sd_printk(KERN_NOTICE, sdkp,
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"Using 0xffffffff as device size\n");
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sdkp->capacity = 1 + (sector_t) 0xffffffff;
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sector_size = old_sector_size;
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goto got_data;
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}
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}
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}
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/* Some devices are known to return the total number of blocks,
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* not the highest block number. Some devices have versions
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