This is the second of several mails containing patches to be included in 2.4.19. Some are worthy of dicussion prior to inclusion and have been marked as such. The majority of these patches were found on lkml; the remaining ones have URLs listed.
This one was both on lkml and ftp://ftp.XX.kernel.org/pub/linux/kernel/people/rgooch/v2.4/sdmany-patch-v3.bz2
I have attached this patch because I have rediffed it to apply nicely to 2.4.19-pre1.
------
Michael Cohen
OhDarn.net
diff -Nru linux-2.4.19-pre1/Documentation/Configure.help linux-patched/Documentation/Configure.help
--- linux-2.4.19-pre1/Documentation/Configure.help Mon Feb 25 20:08:18 2002
+++ linux-patched/Documentation/Configure.help Mon Feb 25 20:08:44 2002
@@ -6667,6 +6667,17 @@
is 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.
+
Maximum number of SCSI disks that can be loaded as modules
CONFIG_SD_EXTRA_DEVS
This controls the amount of additional space allocated in tables for
diff -Nru linux-2.4.19-pre1/drivers/scsi/Config.in linux-patched/drivers/scsi/Config.in
--- linux-2.4.19-pre1/drivers/scsi/Config.in Mon Feb 25 14:38:04 2002
+++ linux-patched/drivers/scsi/Config.in Mon Feb 25 20:08:44 2002
@@ -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 -Nru linux-2.4.19-pre1/drivers/scsi/hosts.h linux-patched/drivers/scsi/hosts.h
--- linux-2.4.19-pre1/drivers/scsi/hosts.h Mon Feb 25 14:38:04 2002
+++ linux-patched/drivers/scsi/hosts.h Mon Feb 25 20:08:44 2002
@@ -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 -Nru linux-2.4.19-pre1/drivers/scsi/osst.c linux-patched/drivers/scsi/osst.c
--- linux-2.4.19-pre1/drivers/scsi/osst.c Fri Dec 21 12:41:55 2001
+++ linux-patched/drivers/scsi/osst.c Mon Feb 25 20:08:44 2002
@@ -162,7 +162,6 @@
name: "OnStream tape",
tag: "osst",
scsi_type: TYPE_TAPE,
- major: OSST_MAJOR,
detect: osst_detect,
init: osst_init,
attach: osst_attach,
diff -Nru linux-2.4.19-pre1/drivers/scsi/scsi_lib.c linux-patched/drivers/scsi/scsi_lib.c
--- linux-2.4.19-pre1/drivers/scsi/scsi_lib.c Fri Oct 12 18:35:54 2001
+++ linux-patched/drivers/scsi/scsi_lib.c Mon Feb 25 20:08:44 2002
@@ -795,25 +795,12 @@
* 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 -Nru linux-2.4.19-pre1/drivers/scsi/sd.c linux-patched/drivers/scsi/sd.c
--- linux-2.4.19-pre1/drivers/scsi/sd.c Mon Feb 25 14:38:04 2002
+++ linux-patched/drivers/scsi/sd.c Mon Feb 25 20:08:44 2002
@@ -28,6 +28,8 @@
*
* Modified by Alex Davis <[email protected]>
* Fix problem where removable media could be ejected after sd_open.
+ *
+ * Modified by Richard Gooch [email protected] to support >128 discs.
*/
#include <linux/config.h>
@@ -65,7 +67,11 @@
* static const char RCSid[] = "$Header:";
*/
+#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);
@@ -1054,6 +1075,43 @@
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.
@@ -1068,17 +1126,22 @@
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_template.dev_noticed = 0;
+ sd_dealloc_majors();
return 1;
}
}
@@ -1088,26 +1151,26 @@
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;
@@ -1131,9 +1194,7 @@
* 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));
@@ -1179,17 +1240,17 @@
if (sd_gendisks != &sd_gendisk)
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);
rscsi_disks = NULL;
cleanup_devfs:
for (i = 0; i < N_USED_SD_MAJORS; i++) {
@@ -1197,6 +1258,7 @@
}
sd_registered--;
sd_template.dev_noticed = 0;
+ sd_dealloc_majors();
return 1;
}
@@ -1402,16 +1464,17 @@
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 -Nru linux-2.4.19-pre1/drivers/scsi/sd.h linux-patched/drivers/scsi/sd.h
--- linux-2.4.19-pre1/drivers/scsi/sd.h Thu Nov 22 14:49:15 2001
+++ linux-patched/drivers/scsi/sd.h Mon Feb 25 20:08:44 2002
@@ -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 -Nru linux-2.4.19-pre1/drivers/scsi/sg.c linux-patched/drivers/scsi/sg.c
--- linux-2.4.19-pre1/drivers/scsi/sg.c Mon Feb 25 14:38:04 2002
+++ linux-patched/drivers/scsi/sg.c Mon Feb 25 20:08:44 2002
@@ -125,7 +125,6 @@
{
tag:"sg",
scsi_type:0xff,
- major:SCSI_GENERIC_MAJOR,
detect:sg_detect,
init:sg_init,
finish:sg_finish,
diff -Nru linux-2.4.19-pre1/drivers/scsi/sr.c linux-patched/drivers/scsi/sr.c
--- linux-2.4.19-pre1/drivers/scsi/sr.c Mon Feb 25 14:38:04 2002
+++ linux-patched/drivers/scsi/sr.c Mon Feb 25 20:08:44 2002
@@ -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 -Nru linux-2.4.19-pre1/drivers/scsi/st.c linux-patched/drivers/scsi/st.c
--- linux-2.4.19-pre1/drivers/scsi/st.c Mon Feb 25 14:38:04 2002
+++ linux-patched/drivers/scsi/st.c Mon Feb 25 20:08:44 2002
@@ -170,7 +170,6 @@
name:"tape",
tag:"st",
scsi_type:TYPE_TAPE,
- major:SCSI_TAPE_MAJOR,
detect:st_detect,
init:st_init,
attach:st_attach,
diff -Nru linux-2.4.19-pre1/include/linux/blk.h linux-patched/include/linux/blk.h
--- linux-2.4.19-pre1/include/linux/blk.h Thu Nov 22 14:48:07 2001
+++ linux-patched/include/linux/blk.h Mon Feb 25 20:08:44 2002
@@ -146,7 +146,11 @@
#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)
> +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
As discussed before - this is a bad idea. Please don't regurgitate random
incorrect patches - it doesnt help. For 2.4 there is no clean way to do
this for 2.5 driverfs and a 32bit dev_t gets you there for free and done
right
Alan Cox writes:
> > +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
>
> As discussed before - this is a bad idea. Please don't regurgitate
> random incorrect patches - it doesnt help. For 2.4 there is no clean
> way to do this for 2.5 driverfs and a 32bit dev_t gets you there for
> free and done right
No, Alan. *You* don't think this is a good idea. Not everyone agrees
with you. My patch is safe: it makes use of the safe major allocation
function so that >128 SD's can be used. You seem to be against this
patch because it would mean that you can't just keep handing out major
numbers, ignoring Linus' "no new majors" decree.
Regards,
Richard....
Permanent: [email protected]
Current: [email protected]
> function so that >128 SD's can be used. You seem to be against this
> patch because it would mean that you can't just keep handing out major
> numbers, ignoring Linus' "no new majors" decree.
Linus no new numbers decree was irrelevant. You can live in your little
ivory tower if it makes you happy, but everyone else works off the post
Linus devices.txt maintained by LANANA.
Even if your hack reflected the newer table it would still be an ugly hack
for a few special case situations rather than any notion of release quality.
Its a very clever devfs hack, but its still an ugly hack
Do it right, and do it in 2.5
Alan
On Tue, 26 Feb 2002, Alan Cox wrote:
> Even if your hack reflected the newer table it would still be an ugly hack
> for a few special case situations rather than any notion of release quality.
> Its a very clever devfs hack, but its still an ugly hack
>
> Do it right, and do it in 2.5
Hate to say it but 2.5 is not ready for any kind of production use, and
some people really need to connect more SCSI devices than are currently
supported. That's NOT ivory tower, it's real world "do it with Linux"
problem solving.
If you have a "do it right" solution which is stable, for a stable kernel,
please let us know. This isn't a theoretical problem.
--
bill davidsen <[email protected]>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.
> Hate to say it but 2.5 is not ready for any kind of production use, and
> some people really need to connect more SCSI devices than are currently
> supported. That's NOT ivory tower, it's real world "do it with Linux"
> problem solving.
I'd be interested to know if Al Viro considers devfs production use ready yet
On Thu, 28 Feb 2002, Alan Cox wrote:
> > Hate to say it but 2.5 is not ready for any kind of production use, and
> > some people really need to connect more SCSI devices than are currently
> > supported. That's NOT ivory tower, it's real world "do it with Linux"
> > problem solving.
>
> I'd be interested to know if Al Viro considers devfs production use ready yet
I would say that is a fair question. I find it in the production kernel?
Good, so it was considered ready by someone. Seems to me one of the Redhat
kernels had devfs as a module, they seem to think so.
It's a good question, though, and I am assuming that the answer is "it's
in the stable kernel" which isn't yes or no.
If it's not stable then there simply is no Linux solution to large
storage. Given what vendors are doing I find that unintuitive.
--
bill davidsen <[email protected]>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.
> I would say that is a fair question. I find it in the production kernel?
> Good, so it was considered ready by someone. Seems to me one of the Redhat
> kernels had devfs as a module, they seem to think so.
<Red Hat on>We don't ship devfs.</Red Hat>
Alan
On Fri, 1 Mar 2002, Alan Cox wrote:
> > I would say that is a fair question. I find it in the production kernel?
> > Good, so it was considered ready by someone. Seems to me one of the Redhat
> > kernels had devfs as a module, they seem to think so.
>
> <Red Hat on>We don't ship devfs.</Red Hat>
Thanks, someone has obviously rebuilt the kernel on the machine I was
considering, possibly even me... :-(
In any case if devfs is stable enough to be in the stable kernel, can we
really say that something using it isn't (for that reason alone)? I any
case I'm still interested, TB are not what they used to be.
Okay, I'll look at other solutions, AIX seems able to handle it.
--
bill davidsen <[email protected]>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.