From 3d310eb7b3df1252e8595d059d982b0a9825a137 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 21 Jun 2005 17:17:26 -0700 Subject: [PATCH] md: fix deadlock due to md thread processing delayed requests. Before completing a 'write' the md superblock might need to be updated. This is best done by the md_thread. The current code schedules this up and queues the write request for later handling by the md_thread. However some personalities (Raid5/raid6) will deadlock if the md_thread tries to submit requests to its own array. So this patch changes things so the processes submitting the request waits for the superblock to be written and then submits the request itself. This fixes a recently-created deadlock in raid5/raid6 Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/raid/md.h | 2 +- include/linux/raid/md_k.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h index cfde8f497d6..75f41d8faed 100644 --- a/include/linux/raid/md.h +++ b/include/linux/raid/md.h @@ -69,7 +69,7 @@ extern mdk_thread_t * md_register_thread (void (*run) (mddev_t *mddev), extern void md_unregister_thread (mdk_thread_t *thread); extern void md_wakeup_thread(mdk_thread_t *thread); extern void md_check_recovery(mddev_t *mddev); -extern int md_write_start(mddev_t *mddev, struct bio *bi); +extern void md_write_start(mddev_t *mddev, struct bio *bi); extern void md_write_end(mddev_t *mddev); extern void md_handle_safemode(mddev_t *mddev); extern void md_done_sync(mddev_t *mddev, int blocks, int ok); diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 6cdcb4434c6..3e977025cf4 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -261,7 +261,7 @@ struct mddev_s sector_t recovery_cp; spinlock_t write_lock; - struct bio_list write_list; + wait_queue_head_t sb_wait; /* for waiting on superblock updates */ unsigned int safemode; /* if set, update "clean" superblock * when no writes pending. -- cgit v1.2.3