From patchwork Sat Jun 13 23:25:41 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC,1/2] dm: introduce target_type method .iterate_devices Date: Sat, 13 Jun 2009 23:25:41 -0000 From: Mike Snitzer X-Patchwork-Id: 30111 Added .iterate_devices to 'struct target_type' to allow a function to be called for all devices in a DM target. Implemented it for both the linear and stripe targets. Once I get confirmation that this infrastructure looks reasonable I'll implement .iterate_devices for the remaining targets. I've not yet bumped each target_type's .version but I assume I need to given the introduction of a new method. Signed-off-by: Mike Snitzer Cc: agk@redhat.com Cc: martin.petersen@oracle.com --- drivers/md/dm-linear.c | 8 ++++++++ drivers/md/dm-stripe.c | 21 +++++++++++++++++++++ include/linux/device-mapper.h | 11 +++++++++++ 3 files changed, 40 insertions(+) -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel Index: linux-2.6/drivers/md/dm-linear.c =================================================================== --- linux-2.6.orig/drivers/md/dm-linear.c +++ linux-2.6/drivers/md/dm-linear.c @@ -132,6 +132,13 @@ static int linear_merge(struct dm_target return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); } +static int linear_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct linear_c *lc = (struct linear_c *) ti->private; + return (fn ? fn(ti, lc->dev, lc->start, data) : 0); +} + static struct target_type linear_target = { .name = "linear", .version= {1, 0, 3}, @@ -142,6 +149,7 @@ static struct target_type linear_target .status = linear_status, .ioctl = linear_ioctl, .merge = linear_merge, + .iterate_devices = linear_iterate_devices, }; int __init dm_linear_init(void) Index: linux-2.6/include/linux/device-mapper.h =================================================================== --- linux-2.6.orig/include/linux/device-mapper.h +++ linux-2.6/include/linux/device-mapper.h @@ -11,6 +11,7 @@ #include #include +struct dm_dev; struct dm_target; struct dm_table; struct mapped_device; @@ -87,6 +88,15 @@ typedef int (*dm_merge_fn) (struct dm_ta */ typedef int (*dm_busy_fn) (struct dm_target *ti); +typedef int (*iterate_devices_callout_fn) (struct dm_target *ti, + struct dm_dev *dev, + sector_t physical_start, + void *data); + +typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, + iterate_devices_callout_fn fn, + void *data); + void dm_error(const char *message); /* @@ -138,6 +148,7 @@ struct target_type { dm_ioctl_fn ioctl; dm_merge_fn merge; dm_busy_fn busy; + dm_iterate_devices_fn iterate_devices; /* For internal device-mapper use. */ struct list_head list; Index: linux-2.6/drivers/md/dm-stripe.c =================================================================== --- linux-2.6.orig/drivers/md/dm-stripe.c +++ linux-2.6/drivers/md/dm-stripe.c @@ -304,6 +304,26 @@ static int stripe_end_io(struct dm_targe return error; } +static int stripe_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + unsigned i; + struct stripe_c *sc = (struct stripe_c *) ti->private; + int ret = 0; + + if (!fn) + return ret; + + for (i = 0; i < sc->stripes; i++) { + ret = fn(ti, sc->stripe[i].dev, + sc->stripe[i].physical_start, data); + if (ret) + break; + } + + return ret; +} + static struct target_type stripe_target = { .name = "striped", .version = {1, 1, 0}, @@ -313,6 +333,7 @@ static struct target_type stripe_target .map = stripe_map, .end_io = stripe_end_io, .status = stripe_status, + .iterate_devices = stripe_iterate_devices, }; int __init dm_stripe_init(void)