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Merge tag 'dm-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/agk/linux-dm

Pull dm fixes from Alasdair G Kergon:
 "A few fixes for problems discovered during the 3.6 cycle.

  Of particular note, are fixes to the thin target's discard support,
  which I hope is finally working correctly; and fixes for multipath
  ioctls and device limits when there are no paths."

* tag 'dm-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm verity: fix overflow check
  dm thin: fix discard support for data devices
  dm thin: tidy discard support
  dm: retain table limits when swapping to new table with no devices
  dm table: clear add_random unless all devices have it set
  dm: handle requests beyond end of device instead of using BUG_ON
  dm mpath: only retry ioctl when no paths if queue_if_no_path set
  dm thin: do not set discard_zeroes_data
  • Loading branch information...
2 parents 99a1300 + 1d55f6b commit c3a086e638e0cf76b26f6053a096354980af9396 @torvalds torvalds committed Sep 28, 2012
Showing with 209 additions and 78 deletions.
  1. +7 −4 drivers/md/dm-mpath.c
  2. +57 −4 drivers/md/dm-table.c
  3. +88 −47 drivers/md/dm-thin.c
  4. +4 −4 drivers/md/dm-verity.c
  5. +52 −19 drivers/md/dm.c
  6. +1 −0 drivers/md/dm.h
View
@@ -1555,6 +1555,7 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
unsigned long arg)
{
struct multipath *m = ti->private;
+ struct pgpath *pgpath;
struct block_device *bdev;
fmode_t mode;
unsigned long flags;
@@ -1570,12 +1571,14 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
if (!m->current_pgpath)
__choose_pgpath(m, 0);
- if (m->current_pgpath) {
- bdev = m->current_pgpath->path.dev->bdev;
- mode = m->current_pgpath->path.dev->mode;
+ pgpath = m->current_pgpath;
+
+ if (pgpath) {
+ bdev = pgpath->path.dev->bdev;
+ mode = pgpath->path.dev->mode;
}
- if (m->queue_io)
+ if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path))
r = -EAGAIN;
else if (!bdev)
r = -EIO;
View
@@ -1212,6 +1212,41 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
return &t->targets[(KEYS_PER_NODE * n) + k];
}
+static int count_device(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ unsigned *num_devices = data;
+
+ (*num_devices)++;
+
+ return 0;
+}
+
+/*
+ * Check whether a table has no data devices attached using each
+ * target's iterate_devices method.
+ * Returns false if the result is unknown because a target doesn't
+ * support iterate_devices.
+ */
+bool dm_table_has_no_data_devices(struct dm_table *table)
+{
+ struct dm_target *uninitialized_var(ti);
+ unsigned i = 0, num_devices = 0;
+
+ while (i < dm_table_get_num_targets(table)) {
+ ti = dm_table_get_target(table, i++);
+
+ if (!ti->type->iterate_devices)
+ return false;
+
+ ti->type->iterate_devices(ti, count_device, &num_devices);
+ if (num_devices)
+ return false;
+ }
+
+ return true;
+}
+
/*
* Establish the new table's queue_limits and validate them.
*/
@@ -1354,17 +1389,25 @@ static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
return q && blk_queue_nonrot(q);
}
-static bool dm_table_is_nonrot(struct dm_table *t)
+static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ struct request_queue *q = bdev_get_queue(dev->bdev);
+
+ return q && !blk_queue_add_random(q);
+}
+
+static bool dm_table_all_devices_attribute(struct dm_table *t,
+ iterate_devices_callout_fn func)
{
struct dm_target *ti;
unsigned i = 0;
- /* Ensure that all underlying device are non-rotational. */
while (i < dm_table_get_num_targets(t)) {
ti = dm_table_get_target(t, i++);
if (!ti->type->iterate_devices ||
- !ti->type->iterate_devices(ti, device_is_nonrot, NULL))
+ !ti->type->iterate_devices(ti, func, NULL))
return 0;
}
@@ -1396,13 +1439,23 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
if (!dm_table_discard_zeroes_data(t))
q->limits.discard_zeroes_data = 0;
- if (dm_table_is_nonrot(t))
+ /* Ensure that all underlying devices are non-rotational. */
+ if (dm_table_all_devices_attribute(t, device_is_nonrot))
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
else
queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
dm_table_set_integrity(t);
+ /*
+ * Determine whether or not this queue's I/O timings contribute
+ * to the entropy pool, Only request-based targets use this.
+ * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
+ * have it set.
+ */
+ if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
+ queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
+
/*
* QUEUE_FLAG_STACKABLE must be set after all queue settings are
* visible to other CPUs because, once the flag is set, incoming bios
View
@@ -509,9 +509,9 @@ enum pool_mode {
struct pool_features {
enum pool_mode mode;
- unsigned zero_new_blocks:1;
- unsigned discard_enabled:1;
- unsigned discard_passdown:1;
+ bool zero_new_blocks:1;
+ bool discard_enabled:1;
+ bool discard_passdown:1;
};
struct thin_c;
@@ -580,7 +580,8 @@ struct pool_c {
struct dm_target_callbacks callbacks;
dm_block_t low_water_blocks;
- struct pool_features pf;
+ struct pool_features requested_pf; /* Features requested during table load */
+ struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
};
/*
@@ -1839,6 +1840,47 @@ static void __requeue_bios(struct pool *pool)
/*----------------------------------------------------------------
* Binding of control targets to a pool object
*--------------------------------------------------------------*/
+static bool data_dev_supports_discard(struct pool_c *pt)
+{
+ struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
+
+ return q && blk_queue_discard(q);
+}
+
+/*
+ * If discard_passdown was enabled verify that the data device
+ * supports discards. Disable discard_passdown if not.
+ */
+static void disable_passdown_if_not_supported(struct pool_c *pt)
+{
+ struct pool *pool = pt->pool;
+ struct block_device *data_bdev = pt->data_dev->bdev;
+ struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
+ sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
+ const char *reason = NULL;
+ char buf[BDEVNAME_SIZE];
+
+ if (!pt->adjusted_pf.discard_passdown)
+ return;
+
+ if (!data_dev_supports_discard(pt))
+ reason = "discard unsupported";
+
+ else if (data_limits->max_discard_sectors < pool->sectors_per_block)
+ reason = "max discard sectors smaller than a block";
+
+ else if (data_limits->discard_granularity > block_size)
+ reason = "discard granularity larger than a block";
+
+ else if (block_size & (data_limits->discard_granularity - 1))
+ reason = "discard granularity not a factor of block size";
+
+ if (reason) {
+ DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason);
+ pt->adjusted_pf.discard_passdown = false;
+ }
+}
+
static int bind_control_target(struct pool *pool, struct dm_target *ti)
{
struct pool_c *pt = ti->private;
@@ -1847,31 +1889,16 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti)
* We want to make sure that degraded pools are never upgraded.
*/
enum pool_mode old_mode = pool->pf.mode;
- enum pool_mode new_mode = pt->pf.mode;
+ enum pool_mode new_mode = pt->adjusted_pf.mode;
if (old_mode > new_mode)
new_mode = old_mode;
pool->ti = ti;
pool->low_water_blocks = pt->low_water_blocks;
- pool->pf = pt->pf;
- set_pool_mode(pool, new_mode);
+ pool->pf = pt->adjusted_pf;
- /*
- * If discard_passdown was enabled verify that the data device
- * supports discards. Disable discard_passdown if not; otherwise
- * -EOPNOTSUPP will be returned.
- */
- /* FIXME: pull this out into a sep fn. */
- if (pt->pf.discard_passdown) {
- struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
- if (!q || !blk_queue_discard(q)) {
- char buf[BDEVNAME_SIZE];
- DMWARN("Discard unsupported by data device (%s): Disabling discard passdown.",
- bdevname(pt->data_dev->bdev, buf));
- pool->pf.discard_passdown = 0;
- }
- }
+ set_pool_mode(pool, new_mode);
return 0;
}
@@ -1889,9 +1916,9 @@ static void unbind_control_target(struct pool *pool, struct dm_target *ti)
static void pool_features_init(struct pool_features *pf)
{
pf->mode = PM_WRITE;
- pf->zero_new_blocks = 1;
- pf->discard_enabled = 1;
- pf->discard_passdown = 1;
+ pf->zero_new_blocks = true;
+ pf->discard_enabled = true;
+ pf->discard_passdown = true;
}
static void __pool_destroy(struct pool *pool)
@@ -2119,13 +2146,13 @@ static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
argc--;
if (!strcasecmp(arg_name, "skip_block_zeroing"))
- pf->zero_new_blocks = 0;
+ pf->zero_new_blocks = false;
else if (!strcasecmp(arg_name, "ignore_discard"))
- pf->discard_enabled = 0;
+ pf->discard_enabled = false;
else if (!strcasecmp(arg_name, "no_discard_passdown"))
- pf->discard_passdown = 0;
+ pf->discard_passdown = false;
else if (!strcasecmp(arg_name, "read_only"))
pf->mode = PM_READ_ONLY;
@@ -2259,21 +2286,24 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
pt->metadata_dev = metadata_dev;
pt->data_dev = data_dev;
pt->low_water_blocks = low_water_blocks;
- pt->pf = pf;
+ pt->adjusted_pf = pt->requested_pf = pf;
ti->num_flush_requests = 1;
+
/*
* Only need to enable discards if the pool should pass
* them down to the data device. The thin device's discard
* processing will cause mappings to be removed from the btree.
*/
if (pf.discard_enabled && pf.discard_passdown) {
ti->num_discard_requests = 1;
+
/*
* Setting 'discards_supported' circumvents the normal
* stacking of discard limits (this keeps the pool and
* thin devices' discard limits consistent).
*/
ti->discards_supported = true;
+ ti->discard_zeroes_data_unsupported = true;
}
ti->private = pt;
@@ -2703,7 +2733,7 @@ static int pool_status(struct dm_target *ti, status_type_t type,
format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
(unsigned long)pool->sectors_per_block,
(unsigned long long)pt->low_water_blocks);
- emit_flags(&pt->pf, result, sz, maxlen);
+ emit_flags(&pt->requested_pf, result, sz, maxlen);
break;
}
@@ -2732,20 +2762,21 @@ static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
-static void set_discard_limits(struct pool *pool, struct queue_limits *limits)
+static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
{
- /*
- * FIXME: these limits may be incompatible with the pool's data device
- */
+ struct pool *pool = pt->pool;
+ struct queue_limits *data_limits;
+
limits->max_discard_sectors = pool->sectors_per_block;
/*
- * This is just a hint, and not enforced. We have to cope with
- * bios that cover a block partially. A discard that spans a block
- * boundary is not sent to this target.
+ * discard_granularity is just a hint, and not enforced.
*/
- limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
- limits->discard_zeroes_data = pool->pf.zero_new_blocks;
+ if (pt->adjusted_pf.discard_passdown) {
+ data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
+ limits->discard_granularity = data_limits->discard_granularity;
+ } else
+ limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
}
static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
@@ -2755,15 +2786,25 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
- if (pool->pf.discard_enabled)
- set_discard_limits(pool, limits);
+
+ /*
+ * pt->adjusted_pf is a staging area for the actual features to use.
+ * They get transferred to the live pool in bind_control_target()
+ * called from pool_preresume().
+ */
+ if (!pt->adjusted_pf.discard_enabled)
+ return;
+
+ disable_passdown_if_not_supported(pt);
+
+ set_discard_limits(pt, limits);
}
static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
- .version = {1, 3, 0},
+ .version = {1, 4, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
@@ -3042,19 +3083,19 @@ static int thin_iterate_devices(struct dm_target *ti,
return 0;
}
+/*
+ * A thin device always inherits its queue limits from its pool.
+ */
static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct thin_c *tc = ti->private;
- struct pool *pool = tc->pool;
- blk_limits_io_min(limits, 0);
- blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
- set_discard_limits(pool, limits);
+ *limits = bdev_get_queue(tc->pool_dev->bdev)->limits;
}
static struct target_type thin_target = {
.name = "thin",
- .version = {1, 3, 0},
+ .version = {1, 4, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,
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