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authorLinus Torvalds <torvalds@linux-foundation.org>2017-12-15 12:53:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-12-15 12:53:37 -0800
commitee1b43ece1533ee60b876fd75ddb20ba1ea186bb (patch)
treed049463295c3aa2fdb21d08509821452b67d2d4f
parent66dbbd72005c5ebdd1de35ba5a41393f01df48d6 (diff)
parentfbc7c07ec23c040179384a1f16b62b6030eb6bdd (diff)
downloadlinux-sh-ee1b43ece1533ee60b876fd75ddb20ba1ea186bb.tar.gz
Merge tag 'for-4.15/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer: - fix a particularly nasty DM core bug in a 4.15 refcount_t conversion. - fix various targets to dm_register_target after module __init resources created; otherwise racing lvm2 commands could result in a NULL pointer during initialization of associated DM kernel module. - fix regression in bio-based DM multipath queue_if_no_path handling. - fix DM bufio's shrinker to reclaim more than one buffer per scan. * tag 'for-4.15/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm bufio: fix shrinker scans when (nr_to_scan < retain_target) dm mpath: fix bio-based multipath queue_if_no_path handling dm: fix various targets to dm_register_target after module __init resources created dm table: fix regression from improper dm_dev_internal.count refcount_t conversion
-rw-r--r--drivers/md/dm-bufio.c8
-rw-r--r--drivers/md/dm-cache-target.c12
-rw-r--r--drivers/md/dm-mpath.c67
-rw-r--r--drivers/md/dm-snap.c48
-rw-r--r--drivers/md/dm-table.c5
-rw-r--r--drivers/md/dm-thin.c22
6 files changed, 100 insertions, 62 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index b8ac591aaaa7..c546b567f3b5 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1611,7 +1611,8 @@ static unsigned long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
int l;
struct dm_buffer *b, *tmp;
unsigned long freed = 0;
- unsigned long count = nr_to_scan;
+ unsigned long count = c->n_buffers[LIST_CLEAN] +
+ c->n_buffers[LIST_DIRTY];
unsigned long retain_target = get_retain_buffers(c);
for (l = 0; l < LIST_SIZE; l++) {
@@ -1647,8 +1648,11 @@ static unsigned long
dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
{
struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker);
+ unsigned long count = READ_ONCE(c->n_buffers[LIST_CLEAN]) +
+ READ_ONCE(c->n_buffers[LIST_DIRTY]);
+ unsigned long retain_target = get_retain_buffers(c);
- return READ_ONCE(c->n_buffers[LIST_CLEAN]) + READ_ONCE(c->n_buffers[LIST_DIRTY]);
+ return (count < retain_target) ? 0 : (count - retain_target);
}
/*
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index cf23a14f9c6a..47407e43b96a 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -3472,18 +3472,18 @@ static int __init dm_cache_init(void)
{
int r;
- r = dm_register_target(&cache_target);
- if (r) {
- DMERR("cache target registration failed: %d", r);
- return r;
- }
-
migration_cache = KMEM_CACHE(dm_cache_migration, 0);
if (!migration_cache) {
dm_unregister_target(&cache_target);
return -ENOMEM;
}
+ r = dm_register_target(&cache_target);
+ if (r) {
+ DMERR("cache target registration failed: %d", r);
+ return r;
+ }
+
return 0;
}
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index c8faa2b85842..f7810cc869ac 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -458,6 +458,38 @@ do { \
} while (0)
/*
+ * Check whether bios must be queued in the device-mapper core rather
+ * than here in the target.
+ *
+ * If MPATHF_QUEUE_IF_NO_PATH and MPATHF_SAVED_QUEUE_IF_NO_PATH hold
+ * the same value then we are not between multipath_presuspend()
+ * and multipath_resume() calls and we have no need to check
+ * for the DMF_NOFLUSH_SUSPENDING flag.
+ */
+static bool __must_push_back(struct multipath *m, unsigned long flags)
+{
+ return ((test_bit(MPATHF_QUEUE_IF_NO_PATH, &flags) !=
+ test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &flags)) &&
+ dm_noflush_suspending(m->ti));
+}
+
+/*
+ * Following functions use READ_ONCE to get atomic access to
+ * all m->flags to avoid taking spinlock
+ */
+static bool must_push_back_rq(struct multipath *m)
+{
+ unsigned long flags = READ_ONCE(m->flags);
+ return test_bit(MPATHF_QUEUE_IF_NO_PATH, &flags) || __must_push_back(m, flags);
+}
+
+static bool must_push_back_bio(struct multipath *m)
+{
+ unsigned long flags = READ_ONCE(m->flags);
+ return __must_push_back(m, flags);
+}
+
+/*
* Map cloned requests (request-based multipath)
*/
static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
@@ -478,7 +510,7 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
pgpath = choose_pgpath(m, nr_bytes);
if (!pgpath) {
- if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
+ if (must_push_back_rq(m))
return DM_MAPIO_DELAY_REQUEUE;
dm_report_EIO(m); /* Failed */
return DM_MAPIO_KILL;
@@ -553,7 +585,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
}
if (!pgpath) {
- if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
+ if (must_push_back_bio(m))
return DM_MAPIO_REQUEUE;
dm_report_EIO(m);
return DM_MAPIO_KILL;
@@ -651,8 +683,7 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags,
(save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) ||
(!save_old_value && queue_if_no_path));
- assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags,
- queue_if_no_path || dm_noflush_suspending(m->ti));
+ assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path);
spin_unlock_irqrestore(&m->lock, flags);
if (!queue_if_no_path) {
@@ -1486,7 +1517,7 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
fail_path(pgpath);
if (atomic_read(&m->nr_valid_paths) == 0 &&
- !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
+ !must_push_back_rq(m)) {
if (error == BLK_STS_IOERR)
dm_report_EIO(m);
/* complete with the original error */
@@ -1521,8 +1552,12 @@ static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone,
if (atomic_read(&m->nr_valid_paths) == 0 &&
!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
- dm_report_EIO(m);
- *error = BLK_STS_IOERR;
+ if (must_push_back_bio(m)) {
+ r = DM_ENDIO_REQUEUE;
+ } else {
+ dm_report_EIO(m);
+ *error = BLK_STS_IOERR;
+ }
goto done;
}
@@ -1957,13 +1992,6 @@ static int __init dm_multipath_init(void)
{
int r;
- r = dm_register_target(&multipath_target);
- if (r < 0) {
- DMERR("request-based register failed %d", r);
- r = -EINVAL;
- goto bad_register_target;
- }
-
kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0);
if (!kmultipathd) {
DMERR("failed to create workqueue kmpathd");
@@ -1985,13 +2013,20 @@ static int __init dm_multipath_init(void)
goto bad_alloc_kmpath_handlerd;
}
+ r = dm_register_target(&multipath_target);
+ if (r < 0) {
+ DMERR("request-based register failed %d", r);
+ r = -EINVAL;
+ goto bad_register_target;
+ }
+
return 0;
+bad_register_target:
+ destroy_workqueue(kmpath_handlerd);
bad_alloc_kmpath_handlerd:
destroy_workqueue(kmultipathd);
bad_alloc_kmultipathd:
- dm_unregister_target(&multipath_target);
-bad_register_target:
return r;
}
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 1113b42e1eda..a0613bd8ed00 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -2411,24 +2411,6 @@ static int __init dm_snapshot_init(void)
return r;
}
- r = dm_register_target(&snapshot_target);
- if (r < 0) {
- DMERR("snapshot target register failed %d", r);
- goto bad_register_snapshot_target;
- }
-
- r = dm_register_target(&origin_target);
- if (r < 0) {
- DMERR("Origin target register failed %d", r);
- goto bad_register_origin_target;
- }
-
- r = dm_register_target(&merge_target);
- if (r < 0) {
- DMERR("Merge target register failed %d", r);
- goto bad_register_merge_target;
- }
-
r = init_origin_hash();
if (r) {
DMERR("init_origin_hash failed.");
@@ -2449,19 +2431,37 @@ static int __init dm_snapshot_init(void)
goto bad_pending_cache;
}
+ r = dm_register_target(&snapshot_target);
+ if (r < 0) {
+ DMERR("snapshot target register failed %d", r);
+ goto bad_register_snapshot_target;
+ }
+
+ r = dm_register_target(&origin_target);
+ if (r < 0) {
+ DMERR("Origin target register failed %d", r);
+ goto bad_register_origin_target;
+ }
+
+ r = dm_register_target(&merge_target);
+ if (r < 0) {
+ DMERR("Merge target register failed %d", r);
+ goto bad_register_merge_target;
+ }
+
return 0;
-bad_pending_cache:
- kmem_cache_destroy(exception_cache);
-bad_exception_cache:
- exit_origin_hash();
-bad_origin_hash:
- dm_unregister_target(&merge_target);
bad_register_merge_target:
dm_unregister_target(&origin_target);
bad_register_origin_target:
dm_unregister_target(&snapshot_target);
bad_register_snapshot_target:
+ kmem_cache_destroy(pending_cache);
+bad_pending_cache:
+ kmem_cache_destroy(exception_cache);
+bad_exception_cache:
+ exit_origin_hash();
+bad_origin_hash:
dm_exception_store_exit();
return r;
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 88130b5d95f9..aaffd0c0ee9a 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -453,14 +453,15 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
refcount_set(&dd->count, 1);
list_add(&dd->list, &t->devices);
+ goto out;
} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
r = upgrade_mode(dd, mode, t->md);
if (r)
return r;
- refcount_inc(&dd->count);
}
-
+ refcount_inc(&dd->count);
+out:
*result = dd->dm_dev;
return 0;
}
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 89e5dff9b4cf..f91d771fff4b 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -4355,30 +4355,28 @@ static struct target_type thin_target = {
static int __init dm_thin_init(void)
{
- int r;
+ int r = -ENOMEM;
pool_table_init();
+ _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
+ if (!_new_mapping_cache)
+ return r;
+
r = dm_register_target(&thin_target);
if (r)
- return r;
+ goto bad_new_mapping_cache;
r = dm_register_target(&pool_target);
if (r)
- goto bad_pool_target;
-
- r = -ENOMEM;
-
- _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
- if (!_new_mapping_cache)
- goto bad_new_mapping_cache;
+ goto bad_thin_target;
return 0;
-bad_new_mapping_cache:
- dm_unregister_target(&pool_target);
-bad_pool_target:
+bad_thin_target:
dm_unregister_target(&thin_target);
+bad_new_mapping_cache:
+ kmem_cache_destroy(_new_mapping_cache);
return r;
}