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authorEd Cashin <ecashin@coraid.com>2012-10-04 17:16:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-06 03:05:29 +0900
commit4bcce1a355c8248fb5661cb78bb14b9e19475cd4 (patch)
tree6a6db4ec3f569bdbbf925d9419d7f89ce7cace34 /drivers
parent0c966214589b9767fd8771b71328f83bac58cb25 (diff)
downloadlinux-4bcce1a355c8248fb5661cb78bb14b9e19475cd4.tar.bz2
aoe: retain static block device numbers for backwards compatibility
The old mapping between AoE target shelf and slot addresses and the block device minor number is retained as a backwards-compatible feature, with a new "aoe_dyndevs" module parameter available for enabling dynamic block device minor numbers. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/aoe/aoedev.c54
1 files changed, 51 insertions, 3 deletions
diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
index 68a7a5a9ced0..3d494fdfb43d 100644
--- a/drivers/block/aoe/aoedev.c
+++ b/drivers/block/aoe/aoedev.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/bitmap.h>
#include <linux/kdev_t.h>
+#include <linux/moduleparam.h>
#include "aoe.h"
static void dummy_timer(ulong);
@@ -18,6 +19,10 @@ static void aoedev_freedev(struct aoedev *);
static void freetgt(struct aoedev *d, struct aoetgt *t);
static void skbpoolfree(struct aoedev *d);
+static int aoe_dyndevs;
+module_param(aoe_dyndevs, int, 0644);
+MODULE_PARM_DESC(aoe_dyndevs, "Use dynamic minor numbers for devices.");
+
static struct aoedev *devlist;
static DEFINE_SPINLOCK(devlist_lock);
@@ -34,7 +39,7 @@ static DEFINE_SPINLOCK(used_minors_lock);
static DECLARE_BITMAP(used_minors, N_DEVS);
static int
-minor_get(ulong *minor)
+minor_get_dyn(ulong *sysminor)
{
ulong flags;
ulong n;
@@ -48,10 +53,53 @@ minor_get(ulong *minor)
error = -1;
spin_unlock_irqrestore(&used_minors_lock, flags);
- *minor = n * AOE_PARTITIONS;
+ *sysminor = n * AOE_PARTITIONS;
return error;
}
+static int
+minor_get_static(ulong *sysminor, ulong aoemaj, int aoemin)
+{
+ ulong flags;
+ ulong n;
+ int error = 0;
+ enum {
+ /* for backwards compatibility when !aoe_dyndevs,
+ * a static number of supported slots per shelf */
+ NPERSHELF = 16,
+ };
+
+ n = aoemaj * NPERSHELF + aoemin;
+ if (aoemin >= NPERSHELF || n >= N_DEVS) {
+ pr_err("aoe: %s with e%ld.%d\n",
+ "cannot use static minor device numbers",
+ aoemaj, aoemin);
+ error = -1;
+ } else {
+ spin_lock_irqsave(&used_minors_lock, flags);
+ if (test_bit(n, used_minors)) {
+ pr_err("aoe: %s %lu\n",
+ "existing device already has static minor number",
+ n);
+ error = -1;
+ } else
+ set_bit(n, used_minors);
+ spin_unlock_irqrestore(&used_minors_lock, flags);
+ }
+
+ *sysminor = n;
+ return error;
+}
+
+static int
+minor_get(ulong *sysminor, ulong aoemaj, int aoemin)
+{
+ if (aoe_dyndevs)
+ return minor_get_dyn(sysminor);
+ else
+ return minor_get_static(sysminor, aoemaj, aoemin);
+}
+
static void
minor_free(ulong minor)
{
@@ -293,7 +341,7 @@ aoedev_by_aoeaddr(ulong maj, int min, int do_alloc)
d->ref++;
break;
}
- if (d || !do_alloc || minor_get(&sysminor) < 0)
+ if (d || !do_alloc || minor_get(&sysminor, maj, min) < 0)
goto out;
d = kcalloc(1, sizeof *d, GFP_ATOMIC);
if (!d)