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Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r--drivers/md/dm-mpath.c146
1 files changed, 98 insertions, 48 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 73bb23de6336..53645a6f474c 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -128,6 +128,20 @@ static void queue_if_no_path_timeout_work(struct timer_list *t);
#define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */
#define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */
+static bool mpath_double_check_test_bit(int MPATHF_bit, struct multipath *m)
+{
+ bool r = test_bit(MPATHF_bit, &m->flags);
+
+ if (r) {
+ unsigned long flags;
+ spin_lock_irqsave(&m->lock, flags);
+ r = test_bit(MPATHF_bit, &m->flags);
+ spin_unlock_irqrestore(&m->lock, flags);
+ }
+
+ return r;
+}
+
/*-----------------------------------------------
* Allocation routines
*-----------------------------------------------*/
@@ -335,6 +349,8 @@ static int pg_init_all_paths(struct multipath *m)
static void __switch_pg(struct multipath *m, struct priority_group *pg)
{
+ lockdep_assert_held(&m->lock);
+
m->current_pg = pg;
/* Must we initialise the PG first, and queue I/O till it's ready? */
@@ -382,7 +398,9 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
unsigned bypassed = 1;
if (!atomic_read(&m->nr_valid_paths)) {
+ spin_lock_irqsave(&m->lock, flags);
clear_bit(MPATHF_QUEUE_IO, &m->flags);
+ spin_unlock_irqrestore(&m->lock, flags);
goto failed;
}
@@ -422,8 +440,11 @@ check_current_pg:
continue;
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath)) {
- if (!bypassed)
+ if (!bypassed) {
+ spin_lock_irqsave(&m->lock, flags);
set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
+ spin_unlock_irqrestore(&m->lock, flags);
+ }
return pgpath;
}
}
@@ -465,7 +486,14 @@ static bool __must_push_back(struct multipath *m)
static bool must_push_back_rq(struct multipath *m)
{
- return test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || __must_push_back(m);
+ unsigned long flags;
+ bool ret;
+
+ spin_lock_irqsave(&m->lock, flags);
+ ret = (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || __must_push_back(m));
+ spin_unlock_irqrestore(&m->lock, flags);
+
+ return ret;
}
/*
@@ -485,7 +513,7 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
/* Do we need to select a new pgpath? */
pgpath = READ_ONCE(m->current_pgpath);
- if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags))
+ if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m))
pgpath = choose_pgpath(m, nr_bytes);
if (!pgpath) {
@@ -493,8 +521,8 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
return DM_MAPIO_DELAY_REQUEUE;
dm_report_EIO(m); /* Failed */
return DM_MAPIO_KILL;
- } else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
- test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
+ } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) ||
+ mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) {
pg_init_all_paths(m);
return DM_MAPIO_DELAY_REQUEUE;
}
@@ -560,33 +588,45 @@ static void multipath_release_clone(struct request *clone,
* Map cloned bios (bio-based multipath)
*/
+static void __multipath_queue_bio(struct multipath *m, struct bio *bio)
+{
+ /* Queue for the daemon to resubmit */
+ bio_list_add(&m->queued_bios, bio);
+ if (!test_bit(MPATHF_QUEUE_IO, &m->flags))
+ queue_work(kmultipathd, &m->process_queued_bios);
+}
+
+static void multipath_queue_bio(struct multipath *m, struct bio *bio)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&m->lock, flags);
+ __multipath_queue_bio(m, bio);
+ spin_unlock_irqrestore(&m->lock, flags);
+}
+
static struct pgpath *__map_bio(struct multipath *m, struct bio *bio)
{
struct pgpath *pgpath;
unsigned long flags;
- bool queue_io;
/* Do we need to select a new pgpath? */
pgpath = READ_ONCE(m->current_pgpath);
- if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags))
+ if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m))
pgpath = choose_pgpath(m, bio->bi_iter.bi_size);
- /* MPATHF_QUEUE_IO might have been cleared by choose_pgpath. */
- queue_io = test_bit(MPATHF_QUEUE_IO, &m->flags);
-
- if ((pgpath && queue_io) ||
- (!pgpath && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))) {
- /* Queue for the daemon to resubmit */
+ if (!pgpath) {
spin_lock_irqsave(&m->lock, flags);
- bio_list_add(&m->queued_bios, bio);
+ if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
+ __multipath_queue_bio(m, bio);
+ pgpath = ERR_PTR(-EAGAIN);
+ }
spin_unlock_irqrestore(&m->lock, flags);
- /* PG_INIT_REQUIRED cannot be set without QUEUE_IO */
- if (queue_io || test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
- pg_init_all_paths(m);
- else if (!queue_io)
- queue_work(kmultipathd, &m->process_queued_bios);
-
+ } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) ||
+ mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) {
+ multipath_queue_bio(m, bio);
+ pg_init_all_paths(m);
return ERR_PTR(-EAGAIN);
}
@@ -835,7 +875,7 @@ static int setup_scsi_dh(struct block_device *bdev, struct multipath *m,
struct request_queue *q = bdev_get_queue(bdev);
int r;
- if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) {
+ if (mpath_double_check_test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, m)) {
retain:
if (*attached_handler_name) {
/*
@@ -1614,7 +1654,7 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
if (pgpath)
fail_path(pgpath);
- if (atomic_read(&m->nr_valid_paths) == 0 &&
+ if (!atomic_read(&m->nr_valid_paths) &&
!must_push_back_rq(m)) {
if (error == BLK_STS_IOERR)
dm_report_EIO(m);
@@ -1649,23 +1689,22 @@ static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone,
if (pgpath)
fail_path(pgpath);
- if (atomic_read(&m->nr_valid_paths) == 0 &&
- !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
- if (__must_push_back(m)) {
- r = DM_ENDIO_REQUEUE;
- } else {
- dm_report_EIO(m);
- *error = BLK_STS_IOERR;
+ if (!atomic_read(&m->nr_valid_paths)) {
+ spin_lock_irqsave(&m->lock, flags);
+ if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
+ if (__must_push_back(m)) {
+ r = DM_ENDIO_REQUEUE;
+ } else {
+ dm_report_EIO(m);
+ *error = BLK_STS_IOERR;
+ }
+ spin_unlock_irqrestore(&m->lock, flags);
+ goto done;
}
- goto done;
+ spin_unlock_irqrestore(&m->lock, flags);
}
- spin_lock_irqsave(&m->lock, flags);
- bio_list_add(&m->queued_bios, clone);
- spin_unlock_irqrestore(&m->lock, flags);
- if (!test_bit(MPATHF_QUEUE_IO, &m->flags))
- queue_work(kmultipathd, &m->process_queued_bios);
-
+ multipath_queue_bio(m, clone);
r = DM_ENDIO_INCOMPLETE;
done:
if (pgpath) {
@@ -1937,16 +1976,17 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev)
{
struct multipath *m = ti->private;
- struct pgpath *current_pgpath;
+ struct pgpath *pgpath;
+ unsigned long flags;
int r;
- current_pgpath = READ_ONCE(m->current_pgpath);
- if (!current_pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags))
- current_pgpath = choose_pgpath(m, 0);
+ pgpath = READ_ONCE(m->current_pgpath);
+ if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m))
+ pgpath = choose_pgpath(m, 0);
- if (current_pgpath) {
- if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) {
- *bdev = current_pgpath->path.dev->bdev;
+ if (pgpath) {
+ if (!mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) {
+ *bdev = pgpath->path.dev->bdev;
r = 0;
} else {
/* pg_init has not started or completed */
@@ -1954,10 +1994,11 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
}
} else {
/* No path is available */
+ r = -EIO;
+ spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
r = -ENOTCONN;
- else
- r = -EIO;
+ spin_unlock_irqrestore(&m->lock, flags);
}
if (r == -ENOTCONN) {
@@ -1965,8 +2006,10 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
/* Path status changed, redo selection */
(void) choose_pgpath(m, 0);
}
+ spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
- pg_init_all_paths(m);
+ (void) __pg_init_all_paths(m);
+ spin_unlock_irqrestore(&m->lock, flags);
dm_table_run_md_queue_async(m->ti->table);
process_queued_io_list(m);
}
@@ -2026,8 +2069,15 @@ static int multipath_busy(struct dm_target *ti)
return true;
/* no paths available, for blk-mq: rely on IO mapping to delay requeue */
- if (!atomic_read(&m->nr_valid_paths) && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
- return (m->queue_mode != DM_TYPE_REQUEST_BASED);
+ if (!atomic_read(&m->nr_valid_paths)) {
+ unsigned long flags;
+ spin_lock_irqsave(&m->lock, flags);
+ if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
+ spin_unlock_irqrestore(&m->lock, flags);
+ return (m->queue_mode != DM_TYPE_REQUEST_BASED);
+ }
+ spin_unlock_irqrestore(&m->lock, flags);
+ }
/* Guess which priority_group will be used at next mapping time */
pg = READ_ONCE(m->current_pg);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 01:03:39 +0100