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path: root/drivers/md/dm-snap.c
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Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c124
1 files changed, 111 insertions, 13 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 864b03f47727..f83a0f3fc365 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -20,6 +20,8 @@
#include <linux/log2.h>
#include <linux/dm-kcopyd.h>
+#include "dm.h"
+
#include "dm-exception-store.h"
#define DM_MSG_PREFIX "snapshots"
@@ -291,12 +293,23 @@ struct origin {
};
/*
+ * This structure is allocated for each origin target
+ */
+struct dm_origin {
+ struct dm_dev *dev;
+ struct dm_target *ti;
+ unsigned split_boundary;
+ struct list_head hash_list;
+};
+
+/*
* Size of the hash table for origin volumes. If we make this
* the size of the minors list then it should be nearly perfect
*/
#define ORIGIN_HASH_SIZE 256
#define ORIGIN_MASK 0xFF
static struct list_head *_origins;
+static struct list_head *_dm_origins;
static struct rw_semaphore _origins_lock;
static DECLARE_WAIT_QUEUE_HEAD(_pending_exceptions_done);
@@ -310,12 +323,22 @@ static int init_origin_hash(void)
_origins = kmalloc(ORIGIN_HASH_SIZE * sizeof(struct list_head),
GFP_KERNEL);
if (!_origins) {
- DMERR("unable to allocate memory");
+ DMERR("unable to allocate memory for _origins");
return -ENOMEM;
}
-
for (i = 0; i < ORIGIN_HASH_SIZE; i++)
INIT_LIST_HEAD(_origins + i);
+
+ _dm_origins = kmalloc(ORIGIN_HASH_SIZE * sizeof(struct list_head),
+ GFP_KERNEL);
+ if (!_dm_origins) {
+ DMERR("unable to allocate memory for _dm_origins");
+ kfree(_origins);
+ return -ENOMEM;
+ }
+ for (i = 0; i < ORIGIN_HASH_SIZE; i++)
+ INIT_LIST_HEAD(_dm_origins + i);
+
init_rwsem(&_origins_lock);
return 0;
@@ -324,6 +347,7 @@ static int init_origin_hash(void)
static void exit_origin_hash(void)
{
kfree(_origins);
+ kfree(_dm_origins);
}
static unsigned origin_hash(struct block_device *bdev)
@@ -350,6 +374,30 @@ static void __insert_origin(struct origin *o)
list_add_tail(&o->hash_list, sl);
}
+static struct dm_origin *__lookup_dm_origin(struct block_device *origin)
+{
+ struct list_head *ol;
+ struct dm_origin *o;
+
+ ol = &_dm_origins[origin_hash(origin)];
+ list_for_each_entry (o, ol, hash_list)
+ if (bdev_equal(o->dev->bdev, origin))
+ return o;
+
+ return NULL;
+}
+
+static void __insert_dm_origin(struct dm_origin *o)
+{
+ struct list_head *sl = &_dm_origins[origin_hash(o->dev->bdev)];
+ list_add_tail(&o->hash_list, sl);
+}
+
+static void __remove_dm_origin(struct dm_origin *o)
+{
+ list_del(&o->hash_list);
+}
+
/*
* _origins_lock must be held when calling this function.
* Returns number of snapshots registered using the supplied cow device, plus:
@@ -1432,8 +1480,6 @@ out:
full_bio->bi_private = pe->full_bio_private;
atomic_inc(&full_bio->bi_remaining);
}
- free_pending_exception(pe);
-
increment_pending_exceptions_done_count();
up_write(&s->lock);
@@ -1450,6 +1496,8 @@ out:
}
retry_origin_bios(s, origin_bios);
+
+ free_pending_exception(pe);
}
static void commit_callback(void *context, int success)
@@ -1840,9 +1888,40 @@ static int snapshot_preresume(struct dm_target *ti)
static void snapshot_resume(struct dm_target *ti)
{
struct dm_snapshot *s = ti->private;
- struct dm_snapshot *snap_src = NULL, *snap_dest = NULL;
+ struct dm_snapshot *snap_src = NULL, *snap_dest = NULL, *snap_merging = NULL;
+ struct dm_origin *o;
+ struct mapped_device *origin_md = NULL;
+ bool must_restart_merging = false;
+
+ down_read(&_origins_lock);
+
+ o = __lookup_dm_origin(s->origin->bdev);
+ if (o)
+ origin_md = dm_table_get_md(o->ti->table);
+ if (!origin_md) {
+ (void) __find_snapshots_sharing_cow(s, NULL, NULL, &snap_merging);
+ if (snap_merging)
+ origin_md = dm_table_get_md(snap_merging->ti->table);
+ }
+ if (origin_md == dm_table_get_md(ti->table))
+ origin_md = NULL;
+ if (origin_md) {
+ if (dm_hold(origin_md))
+ origin_md = NULL;
+ }
+
+ up_read(&_origins_lock);
+
+ if (origin_md) {
+ dm_internal_suspend_fast(origin_md);
+ if (snap_merging && test_bit(RUNNING_MERGE, &snap_merging->state_bits)) {
+ must_restart_merging = true;
+ stop_merge(snap_merging);
+ }
+ }
down_read(&_origins_lock);
+
(void) __find_snapshots_sharing_cow(s, &snap_src, &snap_dest, NULL);
if (snap_src && snap_dest) {
down_write(&snap_src->lock);
@@ -1851,8 +1930,16 @@ static void snapshot_resume(struct dm_target *ti)
up_write(&snap_dest->lock);
up_write(&snap_src->lock);
}
+
up_read(&_origins_lock);
+ if (origin_md) {
+ if (must_restart_merging)
+ start_merge(snap_merging);
+ dm_internal_resume_fast(origin_md);
+ dm_put(origin_md);
+ }
+
/* Now we have correct chunk size, reregister */
reregister_snapshot(s);
@@ -2133,11 +2220,6 @@ static int origin_write_extent(struct dm_snapshot *merging_snap,
* Origin: maps a linear range of a device, with hooks for snapshotting.
*/
-struct dm_origin {
- struct dm_dev *dev;
- unsigned split_boundary;
-};
-
/*
* Construct an origin mapping: <dev_path>
* The context for an origin is merely a 'struct dm_dev *'
@@ -2166,6 +2248,7 @@ static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad_open;
}
+ o->ti = ti;
ti->private = o;
ti->num_flush_bios = 1;
@@ -2180,6 +2263,7 @@ bad_alloc:
static void origin_dtr(struct dm_target *ti)
{
struct dm_origin *o = ti->private;
+
dm_put_device(ti, o->dev);
kfree(o);
}
@@ -2216,6 +2300,19 @@ static void origin_resume(struct dm_target *ti)
struct dm_origin *o = ti->private;
o->split_boundary = get_origin_minimum_chunksize(o->dev->bdev);
+
+ down_write(&_origins_lock);
+ __insert_dm_origin(o);
+ up_write(&_origins_lock);
+}
+
+static void origin_postsuspend(struct dm_target *ti)
+{
+ struct dm_origin *o = ti->private;
+
+ down_write(&_origins_lock);
+ __remove_dm_origin(o);
+ up_write(&_origins_lock);
}
static void origin_status(struct dm_target *ti, status_type_t type,
@@ -2258,12 +2355,13 @@ static int origin_iterate_devices(struct dm_target *ti,
static struct target_type origin_target = {
.name = "snapshot-origin",
- .version = {1, 8, 1},
+ .version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = origin_ctr,
.dtr = origin_dtr,
.map = origin_map,
.resume = origin_resume,
+ .postsuspend = origin_postsuspend,
.status = origin_status,
.merge = origin_merge,
.iterate_devices = origin_iterate_devices,
@@ -2271,7 +2369,7 @@ static struct target_type origin_target = {
static struct target_type snapshot_target = {
.name = "snapshot",
- .version = {1, 12, 0},
+ .version = {1, 13, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,
@@ -2285,7 +2383,7 @@ static struct target_type snapshot_target = {
static struct target_type merge_target = {
.name = dm_snapshot_merge_target_name,
- .version = {1, 2, 0},
+ .version = {1, 3, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 14:14:13 +0300