[PATCH] md - 3 of 3 - Avoid races by never no releasing rdev->sb for faulty devices.
From: NeilBrown <hidden>
Date: 2002-12-17 02:00:50
There are races relating to the superblocks being written out just as a device has failed, and the rdev->sb getting freeing while it is being written out. This patch tries to avoid one of the races by testing the faulty bit in the superblock (which gets set early) as well as rdev->faulty (which gets set late), and does not free rdev->sb until the rdev is fully removed, thus making the races less critical. ----------- Diffstat output ------------ ./drivers/md/md.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-) diff ./drivers/md/md.c~current~ ./drivers/md/md.c
--- ./drivers/md/md.c~current~ 2002-12-16 16:29:52.000000000 +1100
+++ ./drivers/md/md.c 2002-12-16 16:30:42.000000000 +1100@@ -1048,7 +1048,11 @@ repeat: printk("(skipping faulty "); if (rdev->alias_device) printk("(skipping alias "); - + if (disk_faulty(&rdev->sb->this_disk)) { + printk("(skipping new-faulty %s )\n", + partition_name(rdev->dev)); + continue; + } printk("%s ", partition_name(rdev->dev)); if (!rdev->faulty && !rdev->alias_device) { printk("[events: %08lx]",
@@ -1075,7 +1079,6 @@ repeat: * - the device is nonexistent (zero size) * - the device has no valid superblock * - * a faulty rdev _never_ has rdev->sb set. */ static int md_import_device(kdev_t newdev, int on_disk) {
@@ -1147,8 +1150,6 @@ static int md_import_device(kdev_t newde md_list_add(&rdev->all, &all_raid_disks); MD_INIT_LIST_HEAD(&rdev->pending); - if (rdev->faulty && rdev->sb) - free_disk_sb(rdev); return 0; abort_free:
@@ -3062,7 +3063,6 @@ int md_error(mddev_t *mddev, kdev_t rdev return 0; if (!mddev->pers->error_handler || mddev->pers->error_handler(mddev,rdev) <= 0) { - free_disk_sb(rrdev); rrdev->faulty = 1; } else return 1;