diff options
| author | Ed Cashin <ecashin@coraid.com> | 2012-10-04 17:16:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-06 03:05:29 +0900 |
| commit | 4bcce1a355c8248fb5661cb78bb14b9e19475cd4 (patch) | |
| tree | 6a6db4ec3f569bdbbf925d9419d7f89ce7cace34 /drivers | |
| parent | 0c966214589b9767fd8771b71328f83bac58cb25 (diff) | |
| download | linux-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.c | 54 |
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) |