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authorGuoqing Jiang <gqjiang@suse.com>2019-06-14 12:10:36 +0300
committerSong Liu <songliubraving@fb.com>2019-06-21 02:36:00 +0300
commit963c555e75b033202dd76cf6325a7b7c83d08d5f (patch)
tree093639f1a814ce053bee95459f4f9c242dfc72ea /drivers/md/md.c
parent3e148a3209792e04f63ec99701235c960765fc9a (diff)
downloadlinux-963c555e75b033202dd76cf6325a7b7c83d08d5f.tar.xz
md: introduce mddev_create/destroy_wb_pool for the change of member device
Previously, we called rdev_init_wb to avoid potential data inconsistency when array is created. Now, we need to call the function and create mempool if a device is added or just be flaged as "writemostly". So mddev_create_wb_pool is introduced and called accordingly. And for safety reason, we mark implicit GFP_NOIO allocation scope for create mempool during mddev_suspend/mddev_resume. And mempool should be removed conversely after remove a member device or its's "writemostly" flag, which is done by call mddev_destroy_wb_pool. Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Song Liu <songliubraving@fb.com>
Diffstat (limited to 'drivers/md/md.c')
-rw-r--r--drivers/md/md.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9a9762c83cc8..b43207ab00b2 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -37,6 +37,7 @@
*/
+#include <linux/sched/mm.h>
#include <linux/sched/signal.h>
#include <linux/kthread.h>
#include <linux/blkdev.h>
@@ -137,6 +138,64 @@ static int rdev_init_wb(struct md_rdev *rdev)
return 1;
}
+/*
+ * Create wb_info_pool if rdev is the first multi-queue device flaged
+ * with writemostly, also write-behind mode is enabled.
+ */
+void mddev_create_wb_pool(struct mddev *mddev, struct md_rdev *rdev,
+ bool is_suspend)
+{
+ if (mddev->bitmap_info.max_write_behind == 0)
+ return;
+
+ if (!test_bit(WriteMostly, &rdev->flags) || !rdev_init_wb(rdev))
+ return;
+
+ if (mddev->wb_info_pool == NULL) {
+ unsigned int noio_flag;
+
+ if (!is_suspend)
+ mddev_suspend(mddev);
+ noio_flag = memalloc_noio_save();
+ mddev->wb_info_pool = mempool_create_kmalloc_pool(NR_WB_INFOS,
+ sizeof(struct wb_info));
+ memalloc_noio_restore(noio_flag);
+ if (!mddev->wb_info_pool)
+ pr_err("can't alloc memory pool for writemostly\n");
+ if (!is_suspend)
+ mddev_resume(mddev);
+ }
+}
+EXPORT_SYMBOL_GPL(mddev_create_wb_pool);
+
+/*
+ * destroy wb_info_pool if rdev is the last device flaged with WBCollisionCheck.
+ */
+static void mddev_destroy_wb_pool(struct mddev *mddev, struct md_rdev *rdev)
+{
+ if (!test_and_clear_bit(WBCollisionCheck, &rdev->flags))
+ return;
+
+ if (mddev->wb_info_pool) {
+ struct md_rdev *temp;
+ int num = 0;
+
+ /*
+ * Check if other rdevs need wb_info_pool.
+ */
+ rdev_for_each(temp, mddev)
+ if (temp != rdev &&
+ test_bit(WBCollisionCheck, &temp->flags))
+ num++;
+ if (!num) {
+ mddev_suspend(rdev->mddev);
+ mempool_destroy(mddev->wb_info_pool);
+ mddev->wb_info_pool = NULL;
+ mddev_resume(rdev->mddev);
+ }
+ }
+}
+
static struct ctl_table_header *raid_table_header;
static struct ctl_table raid_table[] = {
@@ -2223,6 +2282,9 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
rdev->mddev = mddev;
pr_debug("md: bind<%s>\n", b);
+ if (mddev->raid_disks)
+ mddev_create_wb_pool(mddev, rdev, false);
+
if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
goto fail;
@@ -2259,6 +2321,7 @@ static void unbind_rdev_from_array(struct md_rdev *rdev)
bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
list_del_rcu(&rdev->same_set);
pr_debug("md: unbind<%s>\n", bdevname(rdev->bdev,b));
+ mddev_destroy_wb_pool(rdev->mddev, rdev);
rdev->mddev = NULL;
sysfs_remove_link(&rdev->kobj, "block");
sysfs_put(rdev->sysfs_state);
@@ -2771,8 +2834,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
}
} else if (cmd_match(buf, "writemostly")) {
set_bit(WriteMostly, &rdev->flags);
+ mddev_create_wb_pool(rdev->mddev, rdev, false);
err = 0;
} else if (cmd_match(buf, "-writemostly")) {
+ mddev_destroy_wb_pool(rdev->mddev, rdev);
clear_bit(WriteMostly, &rdev->flags);
err = 0;
} else if (cmd_match(buf, "blocked")) {