Change default value of max_report_luns to 16k-1.
Use data returned from max report luns command to configure the number
of logical units present if previous default of 511 isn't enough.
Signed-off-by: Rob Evers <revers@xxxxxxxxxx>
---
drivers/scsi/scsi_scan.c | 79 +++++++++++++++++++++++++++++++++++-------------
1 file changed, 58 insertions(+), 21 deletions(-)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index b2abf22..0f7ce45 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -109,12 +109,13 @@ MODULE_PARM_DESC(scan, "sync, async or none");
* in practice, the maximum number of LUNs suppored by any device
* is about 16k.
*/
-static unsigned int max_scsi_report_luns = 511;
+static unsigned int max_scsi_report_luns = 16383;
module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_report_luns,
"REPORT LUNS maximum number of LUNS received (should be"
- " between 1 and 16384)");
+ " between 1 and 16383)");
+#define INITIAL_MAX_REPORT_LUNS 511
static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
@@ -1366,9 +1367,10 @@ static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
char devname[64];
unsigned int length;
unsigned int lun;
- unsigned int num_luns;
+ unsigned int num_luns, num_luns_reported;
int result;
struct scsi_lun *lunp, *lun_data;
+ struct scsi_lun *first_lun_data, *second_lun_data;
u8 *data;
struct scsi_device *sdev;
struct Scsi_Host *shost = dev_to_shost(&starget->dev);
@@ -1409,45 +1411,80 @@ static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
/*
* Allocate enough to hold the header (the same size as one scsi_lun)
* plus the max number of luns we are requesting.
- *
- * Reallocating and trying again (with the exact amount we need)
- * would be nice, but then we need to somehow limit the size
- * allocated based on the available memory and the limits of
- * kmalloc - we don't want a kmalloc() failure of a huge value to
- * prevent us from finding any LUNs on this target.
*/
- length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
- lun_data = kmalloc(length, GFP_ATOMIC |
- (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
- if (!lun_data) {
+ if (max_scsi_report_luns > INITIAL_MAX_REPORT_LUNS)
+ length = (INITIAL_MAX_REPORT_LUNS + 1) *
+ sizeof(struct scsi_lun);
+ else
+ length = (max_scsi_report_luns + 1) *
+ sizeof(struct scsi_lun);
+
+ first_lun_data = kmalloc(length, GFP_ATOMIC |
+ (sdev->host->unchecked_isa_dma ?
+ __GFP_DMA : 0));
+ if (!first_lun_data) {
printk(ALLOC_FAILURE_MSG, __func__);
goto out;
}
- result = scsi_do_report_luns(sdev, length, lun_data, devname);
+ result = scsi_do_report_luns(sdev, length, first_lun_data, devname);
if (result) {
/*
* The device probably does not support a REPORT LUN command
*/
+ lun_data = first_lun_data;
ret = 1;
goto out_err;
}
/*
- * Get the length from the first four bytes of lun_data.
+ * Get the length from the first four bytes of first_lun_data.
*/
- data = (u8 *) lun_data->scsi_lun;
+ data = (u8 *) first_lun_data->scsi_lun;
length = ((data[0] << 24) | (data[1] << 16) |
(data[2] << 8) | (data[3] << 0));
- num_luns = (length / sizeof(struct scsi_lun));
- if (num_luns > max_scsi_report_luns) {
+ num_luns_reported = (length / sizeof(struct scsi_lun));
+
+ if (num_luns_reported > max_scsi_report_luns) {
+ num_luns = max_scsi_report_luns;
+ length = num_luns * sizeof(struct scsi_lun);
printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
" of %d luns reported, try increasing"
- " max_scsi_report_luns.\n", devname,
- max_scsi_report_luns, num_luns);
- num_luns = max_scsi_report_luns;
+ " max_report_luns parameter.\n", devname,
+ max_scsi_report_luns, num_luns_reported);
+ } else {
+ num_luns = num_luns_reported;
+ }
+
+ if (num_luns > INITIAL_MAX_REPORT_LUNS) {
+ /*
+ * add one for the header
+ */
+ length = length + sizeof(struct scsi_lun);
+ second_lun_data = kmalloc(length, GFP_ATOMIC |
+ (sdev->host->unchecked_isa_dma ?
+ __GFP_DMA : 0));
+ if (!second_lun_data) {
+ num_luns = INITIAL_MAX_REPORT_LUNS;
+ lun_data = first_lun_data;
+ printk(ALLOC_FAILURE_MSG, __func__);
+ printk(KERN_WARNING "scsi: On %s %d of %d luns reported.\n",
+ devname, num_luns,
+ num_luns_reported);
+ } else {
+ kfree(first_lun_data);
+ lun_data = second_lun_data;
+ result = scsi_do_report_luns(sdev, length,
+ lun_data, devname);
+ if (result) {
+ ret = 1;
+ goto out_err;
+ }
+ }
+ } else {
+ lun_data = first_lun_data;
}
SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
--
1.7.11.7
--
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