The commit is pushed to "branch-rh7-3.10.0-327.36.1.vz7.19.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.36.1.vz7.19.3
------>
commit f15082476d7879d16faf25e0c76ed332ebebba14
Author: Maxim Patlasov <mpatla...@virtuozzo.com>
Date: Mon Oct 24 16:43:16 2016 +0400
md: add support for dm-crypted ploops
Previos patch adding support for dm-crypt ploops naively suggested
that every time we build dm-crypt device, crypt_ctr() is called, and
vice versa - every time we dismantle it, crypt_dtr() is called. But
in practice, crypt_ctr/dtr is called more than once because md->map
is RCU-protected. For example, during resize, new dm target is
constructed and registetred in md->map, then the former md->map is
released.
Only dm-crypt knows how to find underlaying ploop device. That's why
the patch implements ploop_modify methods of dm-crypt target. And
only general dm code (dm.c, dm-table.c, dm-ioctl.c and friends) knows
which instance of dm-target is actual and which is obsoleted. That's
why the patch orchestrates calling this new method from general code,
close to __bind/__unbind managing md->map pointer.
https://jira.sw.ru/browse/PSBM-53386
Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com>
Reviewed-by: Andrey Ryabinin <aryabi...@virtuozzo.com>
---
drivers/md/dm-crypt.c | 25 ++++++++++++++++++++-----
drivers/md/dm-ioctl.c | 3 +++
drivers/md/dm-table.c | 15 +++++++++++++++
drivers/md/dm.c | 4 +++-
drivers/md/dm.h | 1 +
include/linux/device-mapper.h | 9 +++++++++
6 files changed, 51 insertions(+), 6 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index bcdd794..41019b8 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1647,10 +1647,8 @@ static void crypt_dtr(struct dm_target *ti)
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
cc->iv_gen_ops->dtr(cc);
- if (cc->dev) {
- ploop_set_dm_crypt_bdev(cc->dev->bdev, NULL);
+ if (cc->dev)
dm_put_device(ti, cc->dev);
- }
kzfree(cc->cipher);
kzfree(cc->cipher_string);
@@ -1919,8 +1917,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int
argc, char **argv)
goto bad;
}
- ploop_set_dm_crypt_bdev(cc->dev->bdev,
dm_md_get_bdev(dm_table_get_md(ti->table)));
-
if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
ti->error = "Invalid device sector";
goto bad;
@@ -2173,6 +2169,24 @@ static void crypt_io_hints(struct dm_target *ti, struct
queue_limits *limits)
limits->max_segment_size = PAGE_SIZE;
}
+static void crypt_ploop_modify(struct dm_target *ti, int action)
+{
+ struct crypt_config *cc = ti->private;
+
+ if (cc && cc->dev)
+ switch (action) {
+ case DM_PLOOP_ATTACH:
+ ploop_set_dm_crypt_bdev(cc->dev->bdev,
+ dm_md_get_bdev(dm_table_get_md(ti->table)));
+ break;
+ case DM_PLOOP_DETACH:
+ ploop_set_dm_crypt_bdev(cc->dev->bdev, NULL);
+ break;
+ default:
+ BUG();
+ }
+}
+
static struct target_type crypt_target = {
.name = "crypt",
.version = {1, 14, 1},
@@ -2188,6 +2202,7 @@ static struct target_type crypt_target = {
.merge = crypt_merge,
.iterate_devices = crypt_iterate_devices,
.io_hints = crypt_io_hints,
+ .ploop_modify = crypt_ploop_modify,
};
static int __init dm_crypt_init(void)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 0fe4233..fd4b2cc 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1029,6 +1029,9 @@ static int do_resume(struct dm_ioctl *param)
return PTR_ERR(old_map);
}
+ dm_table_ploop_modify(old_map, DM_PLOOP_DETACH);
+ dm_table_ploop_modify(new_map, DM_PLOOP_ATTACH);
+
if (dm_table_get_mode(new_map) & FMODE_WRITE)
set_disk_ro(dm_disk(md), 0);
else
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 16ba55a..e910fbe 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1705,3 +1705,18 @@ void dm_table_run_md_queue_async(struct dm_table *t)
}
EXPORT_SYMBOL(dm_table_run_md_queue_async);
+void dm_table_ploop_modify(struct dm_table *t, int action)
+{
+ unsigned int i;
+
+ if (!t)
+ return;
+
+ /* attach or detach the targets */
+ for (i = 0; i < t->num_targets; i++) {
+ struct dm_target *tgt = t->targets + i;
+
+ if (tgt->type->ploop_modify)
+ tgt->type->ploop_modify(tgt, action);
+ }
+}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index a7993cf..210221e 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -3088,7 +3088,9 @@ static void __dm_destroy(struct mapped_device *md, bool
wait)
dm_device_name(md), atomic_read(&md->holders));
dm_sysfs_exit(md);
- dm_table_destroy(__unbind(md));
+ map = __unbind(md);
+ dm_table_ploop_modify(map, DM_PLOOP_DETACH);
+ dm_table_destroy(map);
free_dev(md);
}
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 815afa5..7330c89 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -76,6 +76,7 @@ bool dm_table_request_based(struct dm_table *t);
bool dm_table_mq_request_based(struct dm_table *t);
void dm_table_free_md_mempools(struct dm_table *t);
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
+void dm_table_ploop_modify(struct dm_table *t, int action);
int dm_queue_merge_is_compulsory(struct request_queue *q);
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 0e7360c..bea9446 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -112,6 +112,14 @@ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
typedef void (*dm_io_hints_fn) (struct dm_target *ti,
struct queue_limits *limits);
+typedef void (*dm_ploop_modify_fn) (struct dm_target *ti, int action);
+
+/* "action" arg of dm_ploop_modify_fn */
+enum {
+ DM_PLOOP_ATTACH,
+ DM_PLOOP_DETACH,
+};
+
/*
* Returns:
* 0: The target can handle the next I/O immediately.
@@ -164,6 +172,7 @@ struct target_type {
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
dm_io_hints_fn io_hints;
+ dm_ploop_modify_fn ploop_modify;
/* For internal device-mapper use. */
struct list_head list;
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