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From: Richard Gooch <rgooch@ras.ucalgary.ca>
To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: [RFT] Support for ~2144 SCSI discs
Date: Mon, 30 Jul 2001 20:30:40 -0400
Cc: devfs-announce-list@mobilix.ras.ucalgary.ca
Hi, all. Below is a patch that adds support for large numbers of
SCSI discs (approximately 2144). I'd like people to try this out. I'm
not doing my normal devfs-patch-v??? thing because this is completely
untested (I'm away from my SCSI boxes), and I don't want to put a
possibly FS-corrupting patch on my ftp archive. The code does compile
and link, though.
There are 3 cases I'd like to have tested:
- people with 1 to 16 SCSI discs
- people with 17 to 128 SCSI discs
- people with >128 SCSI discs
because each of these exercises a slightly different setup path.
Please send success or failure reports to me.
REMINDER: be careful with this patch. It could corrupt your FS.
Regards,
Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca
diff -urN linux-2.4.7/Documentation/Configure.help linux/Documentation/Configure.help
--- linux-2.4.7/Documentation/Configure.help Thu Jul 19 20:48:15 2001
+++ linux/Documentation/Configure.help Mon Jul 23 01:19:24 2001
@@ -5410,6 +5410,17 @@
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 2144). 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-2.4.7/Documentation/filesystems/devfs/ChangeLog linux/Documentation/filesystems/devfs/ChangeLog
--- linux-2.4.7/Documentation/filesystems/devfs/ChangeLog Wed Jul 11 17:55:41 2001
+++ linux/Documentation/filesystems/devfs/ChangeLog Mon Jul 30 19:13:00 2001
@@ -1675,3 +1675,13 @@
- Fixed number leak for /dev/cdroms/cdrom%d
- Fixed number leak for /dev/discs/disc%d
+===============================================================================
+Changes for patch v183
+
+- Fixed bug in <devfs_setup> which could hang boot process
+===============================================================================
+Changes for patch v184
+
+- Support large numbers of SCSI discs (~2144)
+
+- Documentation typo fix for fs/devfs/util.c
diff -urN linux-2.4.7/drivers/scsi/Config.in linux/drivers/scsi/Config.in
--- linux-2.4.7/drivers/scsi/Config.in Thu Jul 5 14:28:16 2001
+++ linux/drivers/scsi/Config.in Mon Jul 23 01:19:47 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 (~2144) 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-2.4.7/drivers/scsi/hosts.h linux/drivers/scsi/hosts.h
--- linux-2.4.7/drivers/scsi/hosts.h Fri Jul 20 15:55:46 2001
+++ linux/drivers/scsi/hosts.h Mon Jul 30 19:20:27 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-2.4.7/drivers/scsi/osst.c linux/drivers/scsi/osst.c
--- linux-2.4.7/drivers/scsi/osst.c Fri Jul 20 00:18:15 2001
+++ linux/drivers/scsi/osst.c Mon Jul 30 17:57:27 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-2.4.7/drivers/scsi/scsi_lib.c linux/drivers/scsi/scsi_lib.c
--- linux-2.4.7/drivers/scsi/scsi_lib.c Thu Jul 19 23:48:04 2001
+++ linux/drivers/scsi/scsi_lib.c Mon Jul 30 17:52:35 2001
@@ -769,25 +769,10 @@
* 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-2.4.7/drivers/scsi/sd.c linux/drivers/scsi/sd.c
--- linux-2.4.7/drivers/scsi/sd.c Thu Jul 5 14:28:17 2001
+++ linux/drivers/scsi/sd.c Mon Jul 30 20:10:58 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 +67,7 @@
* static const char RCSid[] = "$Header:";
*/
-#define SD_MAJOR(i) (!(i) ? SCSI_DISK0_MAJOR : SCSI_DISK1_MAJOR-1+(i))
+#define SD_MAJOR(i) sd_template.majors[(i)]
#define SCSI_DISKS_PER_MAJOR 16
#define SD_MAJOR_NUMBER(i) SD_MAJOR((i) >> 8)
@@ -108,12 +110,6 @@
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,
@@ -123,6 +119,19 @@
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 (i) >> 4);
+ }
+ return -ENODEV;
+}
+#endif
static void rw_intr(Scsi_Cmnd * SCpnt);
@@ -1043,6 +1052,41 @@
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_ATOMIC) ) == 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 )
+ 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.
@@ -1057,16 +1101,16 @@
if (sd_template.dev_noticed == 0)
return 0;
- if (!rscsi_disks)
+ if (!rscsi_disks) {
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;
}
}
@@ -1166,6 +1210,7 @@
for (i = 0; i < N_USED_SD_MAJORS; i++) {
devfs_unregister_blkdev(SD_MAJOR(i), "sd");
}
+ sd_dealloc_majors();
sd_registered--;
return 1;
}
@@ -1373,6 +1418,7 @@
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");
diff -urN linux-2.4.7/drivers/scsi/sd.h linux/drivers/scsi/sd.h
--- linux-2.4.7/drivers/scsi/sd.h Fri Jul 20 15:55:46 2001
+++ linux/drivers/scsi/sd.h Mon Jul 30 20:09:12 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
+#ifdef CONFIG_SD_MANY
+#define SD_PARTITION(i) ((sd_devnum_to_index((i)) << 4) | ((i)&0x0f))
+#else
#define SD_MAJOR_MASK (N_SD_MAJORS - 1)
#define SD_PARTITION(i) (((MAJOR(i) & SD_MAJOR_MASK) << 8) | (MINOR(i) & 255))
+#endif
#endif
diff -urN linux-2.4.7/drivers/scsi/sg.c linux/drivers/scsi/sg.c
--- linux-2.4.7/drivers/scsi/sg.c Wed Jul 4 18:39:28 2001
+++ linux/drivers/scsi/sg.c Mon Jul 30 17:57:52 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-2.4.7/drivers/scsi/sr.c linux/drivers/scsi/sr.c
--- linux-2.4.7/drivers/scsi/sr.c Thu Jul 5 14:28:17 2001
+++ linux/drivers/scsi/sr.c Mon Jul 30 17:59:33 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-2.4.7/drivers/scsi/st.c linux/drivers/scsi/st.c
--- linux-2.4.7/drivers/scsi/st.c Fri Jul 20 00:16:32 2001
+++ linux/drivers/scsi/st.c Mon Jul 30 17:58:22 2001
@@ -160,7 +160,6 @@
name:"tape",
tag:"st",
scsi_type:TYPE_TAPE,
- major:SCSI_TAPE_MAJOR,
detect:st_detect,
init:st_init,
attach:st_attach,
diff -urN linux-2.4.7/fs/devfs/base.c linux/fs/devfs/base.c
--- linux-2.4.7/fs/devfs/base.c Wed Jul 11 17:55:41 2001
+++ linux/fs/devfs/base.c Mon Jul 30 19:10:41 2001
@@ -511,6 +511,9 @@
Removed broken devnum allocation and use <devfs_alloc_devnum>.
Fixed old devnum leak by calling new <devfs_dealloc_devnum>.
v0.107
+ 20010712 Richard Gooch <rgooch@atnf.csiro.au>
+ Fixed bug in <devfs_setup> which could hang boot process.
+ v0.108
*/
#include <linux/types.h>
#include <linux/errno.h>
@@ -543,7 +546,7 @@
#include <asm/bitops.h>
#include <asm/atomic.h>
-#define DEVFS_VERSION "0.107 (20010709)"
+#define DEVFS_VERSION "0.108 (20010712)"
#define DEVFS_NAME "devfs"
@@ -1342,12 +1345,12 @@
return NULL;
}
}
- de->u.fcb.autogen = 0;
+ de->u.fcb.autogen = FALSE;
if ( S_ISCHR (mode) || S_ISBLK (mode) )
{
de->u.fcb.u.device.major = major;
de->u.fcb.u.device.minor = minor;
- de->u.fcb.autogen = (devnum == NODEV) ? 0 : 1;
+ de->u.fcb.autogen = (devnum == NODEV) ? FALSE : TRUE;
}
else if ( S_ISREG (mode) ) de->u.fcb.u.file.size = 0;
else
@@ -1418,7 +1421,7 @@
MKDEV (de->u.fcb.u.device.major,
de->u.fcb.u.device.minor) );
}
- de->u.fcb.autogen = 0;
+ de->u.fcb.autogen = FALSE;
return;
}
if (S_ISLNK (de->mode) && de->registered)
@@ -2063,6 +2066,7 @@
{"show", OPTION_SHOW, &boot_options},
{"only", OPTION_ONLY, &boot_options},
{"mount", OPTION_MOUNT, &boot_options},
+ {NULL, 0, NULL}
};
while ( (*str != '\0') && !isspace (*str) )
@@ -2074,7 +2078,7 @@
invert = 1;
str += 2;
}
- for (i = 0; i < sizeof (devfs_options_tab); i++)
+ for (i = 0; devfs_options_tab[i].name != NULL; i++)
{
int len = strlen (devfs_options_tab[i].name);
diff -urN linux-2.4.7/fs/devfs/util.c linux/fs/devfs/util.c
--- linux-2.4.7/fs/devfs/util.c Wed Jul 11 17:55:41 2001
+++ linux/fs/devfs/util.c Mon Jul 30 18:28:12 2001
@@ -39,6 +39,8 @@
Created <devfs_*alloc_major> and <devfs_*alloc_devnum>.
20010710 Richard Gooch <rgooch@atnf.csiro.au>
Created <devfs_*alloc_unique_number>.
+ 20010730 Richard Gooch <rgooch@atnf.csiro.au>
+ Documentation typo fix.
*/
#include <linux/module.h>
#include <linux/init.h>
@@ -214,7 +216,7 @@
/**
* devfs_alloc_major - Allocate a major number.
- * @type: The type of the major (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLOCK)
+ * @type: The type of the major (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK)
* Returns the allocated major, else -1 if none are available.
* This routine is thread safe and does not block.
@@ -238,7 +240,7 @@
/**
* devfs_dealloc_major - Deallocate a major number.
- * @type: The type of the major (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLOCK)
+ * @type: The type of the major (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK)
* @major: The major number.
* This routine is thread safe and does not block.
*/
@@ -282,7 +284,7 @@
/**
* devfs_alloc_devnum - Allocate a device number.
- * @type: The type (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLOCK).
+ * @type: The type (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK).
*
* Returns the allocated device number, else NODEV if none are available.
* This routine is thread safe and may block.
@@ -347,7 +349,7 @@
/**
* devfs_dealloc_devnum - Dellocate a device number.
- * @type: The type (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLOCK).
+ * @type: The type (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK).
* @devnum: The device number.
*
* This routine is thread safe and does not block.
diff -urN linux-2.4.7/include/linux/blk.h linux/include/linux/blk.h
--- linux-2.4.7/include/linux/blk.h Mon Jul 30 19:20:01 2001
+++ linux/include/linux/blk.h Mon Jul 30 20:05:18 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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