[PATCH] sd-many for 2.4.10

Richard Gooch (rgooch@ras.ucalgary.ca)
Mon, 24 Sep 2001 21:09:57 -0600


Hi, Linus. Here is my complete sd-many patch for 2.4.10. It's
tested, it works and it's safe. Please apply.

Patch generated against 2.4.10-pre14 but applies cleanly against
2.4.10.

Regards,

Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca

diff -urN linux-2.4.10-pre14/Documentation/Configure.help linux/Documentation/Configure.help
--- linux-2.4.10-pre14/Documentation/Configure.help Sat Sep 22 00:26:10 2001
+++ linux/Documentation/Configure.help Sat Sep 22 00:36:08 2001
@@ -5453,6 +5453,17 @@
located on a SCSI disk. In this case, do not compile the driver for
your SCSI host adapter (below) as a module either.

+Many SCSI Discs support
+CONFIG_SD_MANY
+ This allows you to support a very large number of SCSI discs
+ (approximately 2080). You will also need to set CONFIG_DEVFS_FS=y
+ later. This option may consume all unassigned block majors
+ (i.e. those which do not have an allocation in
+ Documentation/devices.txt). Enabling this will consume a few extra
+ kilobytes of kernel memory.
+
+ Unless you have a large storage array, say N.
+
Extra SCSI Disks
CONFIG_SD_EXTRA_DEVS
This controls the amount of additional space allocated in tables for
diff -urN linux-2.4.10-pre14/drivers/scsi/Config.in linux/drivers/scsi/Config.in
--- linux-2.4.10-pre14/drivers/scsi/Config.in Sat Sep 22 00:26:14 2001
+++ linux/drivers/scsi/Config.in Sat Sep 22 00:40:04 2001
@@ -3,7 +3,8 @@
dep_tristate ' SCSI disk support' CONFIG_BLK_DEV_SD $CONFIG_SCSI

if [ "$CONFIG_BLK_DEV_SD" != "n" ]; then
- int 'Maximum number of SCSI disks that can be loaded as modules' CONFIG_SD_EXTRA_DEVS 40
+ bool ' Many (~2080) SCSI discs support (requires devfs)' CONFIG_SD_MANY
+ int ' Maximum number of SCSI disks that can be loaded as modules' CONFIG_SD_EXTRA_DEVS 40
fi

dep_tristate ' SCSI tape support' CONFIG_CHR_DEV_ST $CONFIG_SCSI
diff -urN linux-2.4.10-pre14/drivers/scsi/hosts.h linux/drivers/scsi/hosts.h
--- linux-2.4.10-pre14/drivers/scsi/hosts.h Thu Sep 20 22:33:51 2001
+++ linux/drivers/scsi/hosts.h Sat Sep 22 00:27:45 2001
@@ -506,9 +506,8 @@
const char * tag;
struct module * module; /* Used for loadable modules */
unsigned char scsi_type;
- unsigned int major;
- unsigned int min_major; /* Minimum major in range. */
- unsigned int max_major; /* Maximum major in range. */
+ unsigned int *majors; /* Array of majors used by driver */
+ unsigned int num_majors; /* Number of majors used by driver */
unsigned int nr_dev; /* Number currently attached */
unsigned int dev_noticed; /* Number of devices detected. */
unsigned int dev_max; /* Current size of arrays */
diff -urN linux-2.4.10-pre14/drivers/scsi/osst.c linux/drivers/scsi/osst.c
--- linux-2.4.10-pre14/drivers/scsi/osst.c Thu Jul 19 22:18:15 2001
+++ linux/drivers/scsi/osst.c Sat Sep 22 00:27:45 2001
@@ -160,7 +160,6 @@
name: "OnStream tape",
tag: "osst",
scsi_type: TYPE_TAPE,
- major: OSST_MAJOR,
detect: osst_detect,
init: osst_init,
attach: osst_attach,
diff -urN linux-2.4.10-pre14/drivers/scsi/scsi_lib.c linux/drivers/scsi/scsi_lib.c
--- linux-2.4.10-pre14/drivers/scsi/scsi_lib.c Sun Aug 12 11:51:42 2001
+++ linux/drivers/scsi/scsi_lib.c Sat Sep 22 00:27:45 2001
@@ -788,25 +788,10 @@
* Search for a block device driver that supports this
* major.
*/
- if (spnt->blk && spnt->major == major) {
- return spnt;
- }
- /*
- * I am still not entirely satisfied with this solution,
- * but it is good enough for now. Disks have a number of
- * major numbers associated with them, the primary
- * 8, which we test above, and a secondary range of 7
- * different consecutive major numbers. If this ever
- * becomes insufficient, then we could add another function
- * to the structure, and generalize this completely.
- */
- if( spnt->min_major != 0
- && spnt->max_major != 0
- && major >= spnt->min_major
- && major <= spnt->max_major )
- {
- return spnt;
- }
+ int i;
+ if (!spnt->blk || !spnt->majors) continue;
+ for (i = 0; i < spnt->num_majors; ++i)
+ if (spnt->majors[i] == major) return spnt;
}
return NULL;
}
diff -urN linux-2.4.10-pre14/drivers/scsi/sd.c linux/drivers/scsi/sd.c
--- linux-2.4.10-pre14/drivers/scsi/sd.c Sat Sep 22 00:26:14 2001
+++ linux/drivers/scsi/sd.c Sat Sep 22 00:37:11 2001
@@ -28,6 +28,8 @@
*
* Modified by Alex Davis <letmein@erols.com>
* Fix problem where removable media could be ejected after sd_open.
+ *
+ * Modified by Richard Gooch rgooch@atnf.csiro.au to support >128 discs.
*/

#include <linux/config.h>
@@ -65,7 +67,11 @@
* static const char RCSid[] = "$Header:";
*/

-#define SD_MAJOR(i) (!(i) ? SCSI_DISK0_MAJOR : SCSI_DISK1_MAJOR-1+(i))
+#ifdef CONFIG_SD_MANY
+# define SD_MAJOR(i) sd_template.majors[(i)]
+#else
+# define SD_MAJOR(i) (!(i) ? SCSI_DISK0_MAJOR : SCSI_DISK1_MAJOR-1+(i))
+#endif

#define SCSI_DISKS_PER_MAJOR 16
#define SD_MAJOR_NUMBER(i) SD_MAJOR((i) >> 8)
@@ -77,6 +83,14 @@

#define MAX_RETRIES 5

+#ifdef CONFIG_SD_MANY
+# define sdmalloc(size) vmalloc((size))
+# define sdfree(ptr) vfree((ptr))
+#else
+# define sdmalloc(size) kmalloc((size),GFP_ATOMIC)
+# define sdfree(ptr) kfree((ptr))
+#endif
+
/*
* Time out in seconds for disks and Magneto-opticals (which are slower).
*/
@@ -109,12 +123,6 @@
name:"disk",
tag:"sd",
scsi_type:TYPE_DISK,
- major:SCSI_DISK0_MAJOR,
- /*
- * Secondary range of majors that this driver handles.
- */
- min_major:SCSI_DISK1_MAJOR,
- max_major:SCSI_DISK7_MAJOR,
blk:1,
detect:sd_detect,
init:sd_init,
@@ -124,6 +132,19 @@
init_command:sd_init_command,
};

+#ifdef CONFIG_SD_MANY
+static inline int sd_devnum_to_index (int devnum)
+{
+ int i, major = MAJOR (devnum);
+
+ for (i = 0; i < sd_template.num_majors; ++i)
+ {
+ if (sd_template.majors[i] != major) continue;
+ return (i << 4) | (MINOR (devnum) >> 4);
+ }
+ return -ENODEV;
+}
+#endif

static void rw_intr(Scsi_Cmnd * SCpnt);

@@ -1049,6 +1070,43 @@
return i;
}

+static int sd_alloc_majors (void)
+/* Allocate as many majors as required
+ */
+{
+ int i, major;
+
+ if ( ( sd_template.majors =
+ kmalloc (sizeof *sd_template.majors * N_USED_SD_MAJORS,
+ GFP_KERNEL) ) == NULL ) {
+ printk ("sd.c: unable to allocate major array\n");
+ return -ENOMEM;
+ }
+ sd_template.majors[0] = SCSI_DISK0_MAJOR;
+ for (i = 1; (i < N_USED_SD_MAJORS) && (i <N_SD_PREASSIGNED_MAJORS);++i)
+ sd_template.majors[i] = SCSI_DISK1_MAJOR + i - 1;
+ for (; (i >= N_SD_PREASSIGNED_MAJORS) && (i < N_USED_SD_MAJORS); ++i) {
+ if ( ( major = devfs_alloc_major (DEVFS_SPECIAL_BLK) ) < 0 ) {
+ printk (KERN_WARNING __FUNCTION__ "() major[%d] allocation failed\n", i);
+ break;
+ }
+ sd_template.majors[i] = major;
+ }
+ sd_template.dev_max = i * SCSI_DISKS_PER_MAJOR;
+ sd_template.num_majors = i;
+ return 0;
+} /* End Function sd_alloc_majors */
+
+static void sd_dealloc_majors (void)
+/* Deallocate all the allocated majors
+ */
+{
+ int i;
+
+ for (i = sd_template.num_majors - 1; i >= N_SD_PREASSIGNED_MAJORS; --i)
+ devfs_dealloc_major (DEVFS_SPECIAL_BLK, sd_template.majors[i]);
+} /* End Function sd_dealloc_majors */
+
/*
* The sd_init() function looks at all SCSI drives present, determines
* their size, and reads partition table entries for them.
@@ -1063,16 +1121,20 @@
if (sd_template.dev_noticed == 0)
return 0;

- if (!rscsi_disks)
+ if (!rscsi_disks) {
+ if ( in_interrupt () ) {
+ printk (__FUNCTION__ "(): called from interrupt\n");
+ return 1;
+ }
sd_template.dev_max = sd_template.dev_noticed + SD_EXTRA_DEVS;
-
- if (sd_template.dev_max > N_SD_MAJORS * SCSI_DISKS_PER_MAJOR)
- sd_template.dev_max = N_SD_MAJORS * SCSI_DISKS_PER_MAJOR;
+ if ( sd_alloc_majors() ) return 1;
+ }

if (!sd_registered) {
for (i = 0; i < N_USED_SD_MAJORS; i++) {
if (devfs_register_blkdev(SD_MAJOR(i), "sd", &sd_fops)) {
printk("Unable to get major %d for SCSI disk\n", SD_MAJOR(i));
+ sd_dealloc_majors();
return 1;
}
}
@@ -1082,26 +1144,26 @@
if (rscsi_disks)
return 0;

- rscsi_disks = kmalloc(sd_template.dev_max * sizeof(Scsi_Disk), GFP_ATOMIC);
+ rscsi_disks = sdmalloc(sd_template.dev_max * sizeof(Scsi_Disk));
if (!rscsi_disks)
goto cleanup_devfs;
memset(rscsi_disks, 0, sd_template.dev_max * sizeof(Scsi_Disk));

/* for every (necessary) major: */
- sd_sizes = kmalloc((sd_template.dev_max << 4) * sizeof(int), GFP_ATOMIC);
+ sd_sizes = sdmalloc((sd_template.dev_max << 4) * sizeof(int));
if (!sd_sizes)
goto cleanup_disks;
memset(sd_sizes, 0, (sd_template.dev_max << 4) * sizeof(int));

- sd_blocksizes = kmalloc((sd_template.dev_max << 4) * sizeof(int), GFP_ATOMIC);
+ sd_blocksizes = sdmalloc((sd_template.dev_max << 4) * sizeof(int));
if (!sd_blocksizes)
goto cleanup_sizes;

- sd_hardsizes = kmalloc((sd_template.dev_max << 4) * sizeof(int), GFP_ATOMIC);
+ sd_hardsizes = sdmalloc((sd_template.dev_max << 4) * sizeof(int));
if (!sd_hardsizes)
goto cleanup_blocksizes;

- sd_max_sectors = kmalloc((sd_template.dev_max << 4) * sizeof(int), GFP_ATOMIC);
+ sd_max_sectors = sdmalloc((sd_template.dev_max << 4) * sizeof(int));
if (!sd_max_sectors)
goto cleanup_max_sectors;

@@ -1125,9 +1187,7 @@
* FIXME: should unregister blksize_size, hardsect_size and max_sectors when
* the module is unloaded.
*/
- sd = kmalloc((sd_template.dev_max << 4) *
- sizeof(struct hd_struct),
- GFP_ATOMIC);
+ sd = sdmalloc((sd_template.dev_max << 4) * sizeof(struct hd_struct));
if (!sd)
goto cleanup_sd;
memset(sd, 0, (sd_template.dev_max << 4) * sizeof(struct hd_struct));
@@ -1172,21 +1232,22 @@
}
kfree(sd_gendisks);
cleanup_sd_gendisks:
- kfree(sd);
+ sdfree(sd);
cleanup_sd:
- kfree(sd_max_sectors);
+ sdfree(sd_max_sectors);
cleanup_max_sectors:
- kfree(sd_hardsizes);
+ sdfree(sd_hardsizes);
cleanup_blocksizes:
- kfree(sd_blocksizes);
+ sdfree(sd_blocksizes);
cleanup_sizes:
- kfree(sd_sizes);
+ sdfree(sd_sizes);
cleanup_disks:
- kfree(rscsi_disks);
+ sdfree(rscsi_disks);
cleanup_devfs:
for (i = 0; i < N_USED_SD_MAJORS; i++) {
devfs_unregister_blkdev(SD_MAJOR(i), "sd");
}
+ sd_dealloc_majors();
sd_registered--;
return 1;
}
@@ -1385,16 +1446,17 @@

scsi_unregister_module(MODULE_SCSI_DEV, &sd_template);

+ sd_dealloc_majors();
for (i = 0; i < N_USED_SD_MAJORS; i++)
devfs_unregister_blkdev(SD_MAJOR(i), "sd");

sd_registered--;
if (rscsi_disks != NULL) {
- kfree(rscsi_disks);
- kfree(sd_sizes);
- kfree(sd_blocksizes);
- kfree(sd_hardsizes);
- kfree((char *) sd);
+ sdfree(rscsi_disks);
+ sdfree(sd_sizes);
+ sdfree(sd_blocksizes);
+ sdfree(sd_hardsizes);
+ sdfree((char *) sd);
}
for (i = 0; i < N_USED_SD_MAJORS; i++) {
del_gendisk(&sd_gendisks[i]);
diff -urN linux-2.4.10-pre14/drivers/scsi/sd.h linux/drivers/scsi/sd.h
--- linux-2.4.10-pre14/drivers/scsi/sd.h Thu Sep 20 22:33:51 2001
+++ linux/drivers/scsi/sd.h Sat Sep 22 00:27:45 2001
@@ -42,10 +42,14 @@
*/
extern kdev_t sd_find_target(void *host, int tgt);

-#define N_SD_MAJORS 8
+#define N_SD_PREASSIGNED_MAJORS 8

-#define SD_MAJOR_MASK (N_SD_MAJORS - 1)
+#ifdef CONFIG_SD_MANY
+#define SD_PARTITION(i) ((sd_devnum_to_index((i)) << 4) | ((i)&0x0f))
+#else
+#define SD_MAJOR_MASK (N_SD_PREASSIGNED_MAJORS - 1)
#define SD_PARTITION(i) (((MAJOR(i) & SD_MAJOR_MASK) << 8) | (MINOR(i) & 255))
+#endif

#endif

diff -urN linux-2.4.10-pre14/drivers/scsi/sg.c linux/drivers/scsi/sg.c
--- linux-2.4.10-pre14/drivers/scsi/sg.c Sat Sep 22 00:26:14 2001
+++ linux/drivers/scsi/sg.c Sat Sep 22 00:27:45 2001
@@ -123,7 +123,6 @@
{
tag:"sg",
scsi_type:0xff,
- major:SCSI_GENERIC_MAJOR,
detect:sg_detect,
init:sg_init,
finish:sg_finish,
diff -urN linux-2.4.10-pre14/drivers/scsi/sr.c linux/drivers/scsi/sr.c
--- linux-2.4.10-pre14/drivers/scsi/sr.c Sat Sep 22 00:26:14 2001
+++ linux/drivers/scsi/sr.c Sat Sep 22 00:27:45 2001
@@ -69,12 +69,15 @@

static int sr_init_command(Scsi_Cmnd *);

+static unsigned int sr_major = SCSI_CDROM_MAJOR;
+
static struct Scsi_Device_Template sr_template =
{
name:"cdrom",
tag:"sr",
scsi_type:TYPE_ROM,
- major:SCSI_CDROM_MAJOR,
+ majors:&sr_major,
+ num_majors:1,
blk:1,
detect:sr_detect,
init:sr_init,
diff -urN linux-2.4.10-pre14/drivers/scsi/st.c linux/drivers/scsi/st.c
--- linux-2.4.10-pre14/drivers/scsi/st.c Sun Aug 12 12:21:47 2001
+++ linux/drivers/scsi/st.c Sat Sep 22 00:27:45 2001
@@ -166,7 +166,6 @@
name:"tape",
tag:"st",
scsi_type:TYPE_TAPE,
- major:SCSI_TAPE_MAJOR,
detect:st_detect,
init:st_init,
attach:st_attach,
diff -urN linux-2.4.10-pre14/include/linux/blk.h linux/include/linux/blk.h
--- linux-2.4.10-pre14/include/linux/blk.h Thu Sep 20 22:33:32 2001
+++ linux/include/linux/blk.h Sat Sep 22 00:27:45 2001
@@ -144,7 +144,11 @@

#define DEVICE_NAME "scsidisk"
#define TIMEOUT_VALUE (2*HZ)
+#ifdef CONFIG_SD_MANY
+#define DEVICE_NR(device) sd_devnum_to_index((device))
+#else
#define DEVICE_NR(device) (((MAJOR(device) & SD_MAJOR_MASK) << (8 - 4)) + (MINOR(device) >> 4))
+#endif

/* Kludge to use the same number for both char and block major numbers */
#elif (MAJOR_NR == MD_MAJOR) && defined(MD_DRIVER)
-
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