From: Song Liu song@kernel.org
stable inclusion from stable-v5.10.215 commit b07326747952c6f109e4aa92801abac99e1a27fe category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAB04V CVE: CVE-2024-39476
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 3445139e3a594be77eff48bc17eff67cf983daed ]
This reverts commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d.
The original set [1][2] was expected to undo a suboptimal fix in [2], and replace it with a better fix [1]. However, as reported by Dan Moulding [2] causes an issue with raid5 with journal device.
Revert [2] for now to close the issue. We will follow up on another issue reported by Juxiao Bi, as [2] is expected to fix it. We believe this is a good trade-off, because the latter issue happens less freqently.
In the meanwhile, we will NOT revert [1], as it contains the right logic.
[1] commit d6e035aad6c0 ("md: bypass block throttle for superblock update") [2] commit bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")
Reported-by: Dan Moulding dan@danm.net Closes: https://lore.kernel.org/linux-raid/20240123005700.9302-1-dan@danm.net/ Fixes: bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"") Cc: stable@vger.kernel.org # v5.19+ Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Yu Kuai yukuai3@huawei.com Signed-off-by: Song Liu song@kernel.org Reviewed-by: Yu Kuai yukuai3@huawei.com Link: https://lore.kernel.org/r/20240125082131.788600-1-song@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Wang Hai wanghai38@huawei.com Signed-off-by: Li Nan linan122@huawei.com --- drivers/md/raid5.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 6b70c8bdb4be..c4938b1a587e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -36,6 +36,7 @@ */
#include <linux/blkdev.h> +#include <linux/delay.h> #include <linux/kthread.h> #include <linux/raid/pq.h> #include <linux/async_tx.h> @@ -6511,7 +6512,18 @@ static void raid5d(struct md_thread *thread) spin_unlock_irq(&conf->device_lock); md_check_recovery(mddev); spin_lock_irq(&conf->device_lock); + + /* + * Waiting on MD_SB_CHANGE_PENDING below may deadlock + * seeing md_check_recovery() is needed to clear + * the flag when using mdmon. + */ + continue; } + + wait_event_lock_irq(mddev->sb_wait, + !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags), + conf->device_lock); } pr_debug("%d stripes handled\n", handled);