diff --git a/drivers/md/md.c b/drivers/md/md.c index 084a6540a4bd..adf4d7e1d5e1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5337,8 +5337,14 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev) err = -EBUSY; goto out; } - if (bdev) - sync_blockdev(bdev); + if (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags)) { + /* Someone opened the device since we flushed it + * so page cache could be dirty and it is too late + * to flush. So abort + */ + mutex_unlock(&mddev->open_mutex); + return -EBUSY; + } if (mddev->pers) { __md_stop_writes(mddev); @@ -5373,14 +5379,14 @@ static int do_md_stop(struct mddev * mddev, int mode, mutex_unlock(&mddev->open_mutex); return -EBUSY; } - if (bdev) - /* It is possible IO was issued on some other - * open file which was closed before we took ->open_mutex. - * As that was not the last close __blkdev_put will not - * have called sync_blockdev, so we must. + if (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags)) { + /* Someone opened the device since we flushed it + * so page cache could be dirty and it is too late + * to flush. So abort */ - sync_blockdev(bdev); - + mutex_unlock(&mddev->open_mutex); + return -EBUSY; + } if (mddev->pers) { if (mddev->ro) set_disk_ro(disk, 0); @@ -6417,6 +6423,20 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, !test_bit(MD_RECOVERY_NEEDED, &mddev->flags), msecs_to_jiffies(5000)); + if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) { + /* Need to flush page cache, and ensure no-one else opens + * and writes + */ + mutex_lock(&mddev->open_mutex); + if (atomic_read(&mddev->openers) > 1) { + mutex_unlock(&mddev->open_mutex); + err = -EBUSY; + goto abort; + } + set_bit(MD_STILL_CLOSED, &mddev->flags); + mutex_unlock(&mddev->open_mutex); + sync_blockdev(bdev); + } err = mddev_lock(mddev); if (err) { printk(KERN_INFO @@ -6670,6 +6690,7 @@ static int md_open(struct block_device *bdev, fmode_t mode) err = 0; atomic_inc(&mddev->openers); + clear_bit(MD_STILL_CLOSED, &mddev->flags); mutex_unlock(&mddev->open_mutex); check_disk_change(bdev); diff --git a/drivers/md/md.h b/drivers/md/md.h index 53283beda21b..608050c43f17 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -211,6 +211,9 @@ struct mddev { #define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */ #define MD_UPDATE_SB_FLAGS (1 | 2 | 4) /* If these are set, md_update_sb needed */ #define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */ +#define MD_STILL_CLOSED 4 /* If set, then array has not been opened since + * md_ioctl checked on it. + */ int suspended; atomic_t active_io;