Change mutex to rw_semaphore, so that there could be multiple processes inside dm_bufio_lock_read/dm_bufio_unlock_read concurrently.
Signed-off-by: Mikulas Patocka <[email protected]> --- drivers/md/dm-bufio.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) Index: linux-2.6/drivers/md/dm-bufio.c =================================================================== --- linux-2.6.orig/drivers/md/dm-bufio.c 2022-10-10 11:13:57.000000000 +0200 +++ linux-2.6/drivers/md/dm-bufio.c 2022-10-10 11:13:57.000000000 +0200 @@ -81,7 +81,7 @@ * context. */ struct dm_bufio_client { - struct mutex lock; + struct rw_semaphore lock; spinlock_t spinlock; bool no_sleep; @@ -174,7 +174,7 @@ static void dm_bufio_lock(struct dm_bufi if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep) spin_lock_bh(&c->spinlock); else - mutex_lock_nested(&c->lock, dm_bufio_in_request()); + down_write_nested(&c->lock, dm_bufio_in_request()); } static int dm_bufio_trylock(struct dm_bufio_client *c) @@ -182,7 +182,7 @@ static int dm_bufio_trylock(struct dm_bu if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep) return spin_trylock_bh(&c->spinlock); else - return mutex_trylock(&c->lock); + return down_write_trylock(&c->lock); } static void dm_bufio_unlock(struct dm_bufio_client *c) @@ -190,18 +190,18 @@ static void dm_bufio_unlock(struct dm_bu if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep) spin_unlock_bh(&c->spinlock); else - mutex_unlock(&c->lock); + up_write(&c->lock); } void dm_bufio_lock_read(struct dm_bufio_client *c) { - mutex_lock(&c->lock); + down_read(&c->lock); } EXPORT_SYMBOL_GPL(dm_bufio_lock_read); void dm_bufio_unlock_read(struct dm_bufio_client *c) { - mutex_unlock(&c->lock); + up_read(&c->lock); } EXPORT_SYMBOL_GPL(dm_bufio_unlock_read); @@ -1808,7 +1808,7 @@ struct dm_bufio_client *dm_bufio_client_ c->n_buffers[i] = 0; } - mutex_init(&c->lock); + init_rwsem(&c->lock); spin_lock_init(&c->spinlock); INIT_LIST_HEAD(&c->reserved_buffers); c->need_reserved_buffers = reserved_buffers; @@ -1887,7 +1887,6 @@ bad: kmem_cache_destroy(c->slab_buffer); dm_io_client_destroy(c->dm_io); bad_dm_io: - mutex_destroy(&c->lock); kfree(c); bad_client: return ERR_PTR(r); @@ -1935,7 +1934,6 @@ void dm_bufio_client_destroy(struct dm_b kmem_cache_destroy(c->slab_cache); kmem_cache_destroy(c->slab_buffer); dm_io_client_destroy(c->dm_io); - mutex_destroy(&c->lock); if (c->no_sleep) static_branch_dec(&no_sleep_enabled); kfree(c); -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
