From 569083c08dc16c043b4bdd473d41ff85a2b2df9e Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Mon, 7 Mar 2011 09:49:02 +0100 Subject: [PATCH] drbd: fix drbd_delete_device: remove vnr from volumes; idr_remove(); synchronize_rcu(); before cleanup Still missing: rcu_readlock() on the various call sites that access/iterate over those idrs. We don't need a specific write lock, as we only modify from configuration context, which is already strictly serialized. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_main.c | 42 +++++++++++++++++++--------------- 1 file changed, 24 insertions(+), 18 deletions(-) diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 997b2e214670..9f6db5947c65 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2124,7 +2124,9 @@ void drbd_delete_device(unsigned int minor) if (!mdev) return; - idr_remove(&mdev->tconn->volumes, minor); + idr_remove(&mdev->tconn->volumes, mdev->vnr); + idr_remove(&minors, minor); + synchronize_rcu(); /* paranoia asserts */ D_ASSERT(mdev->open_cnt == 0); @@ -2153,7 +2155,6 @@ void drbd_delete_device(unsigned int minor) * allocated from drbd_new_device * and actually free the mdev itself */ drbd_free_mdev(mdev); - idr_remove(&minors, minor); } static void drbd_cleanup(void) @@ -2331,15 +2332,6 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, return ERR_NOMEM; mdev->tconn = tconn; - if (!idr_pre_get(&tconn->volumes, GFP_KERNEL)) - goto out_no_idr; - if (idr_get_new(&tconn->volumes, mdev, &vnr_got)) - goto out_no_idr; - if (vnr_got != vnr) { - dev_err(DEV, "vnr_got (%d) != vnr (%d)\n", vnr_got, vnr); - goto out_no_q; - } - mdev->minor = minor; drbd_init_set_defaults(mdev); @@ -2395,19 +2387,35 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, INIT_LIST_HEAD(&mdev->current_epoch->list); mdev->epochs = 1; + if (!idr_pre_get(&tconn->volumes, GFP_KERNEL)) + goto out_no_vol_idr; + if (idr_get_new(&tconn->volumes, mdev, &vnr_got)) + goto out_no_vol_idr; + if (vnr_got != vnr) { + dev_err(DEV, "vnr_got (%d) != vnr (%d)\n", vnr_got, vnr); + goto out_idr_remove_vol; + } + if (!idr_pre_get(&minors, GFP_KERNEL)) - goto out_no_minor_idr; + goto out_idr_remove_vol; if (idr_get_new(&minors, mdev, &minor_got)) - goto out_no_minor_idr; + goto out_idr_remove_vol; if (minor_got != minor) { - idr_remove(&minors, minor_got); - goto out_no_minor_idr; + /* minor exists, or other idr strangeness? */ + dev_err(DEV, "available minor (%d) != requested minor (%d)\n", + minor_got, minor); + goto out_idr_remove_minor; } add_disk(disk); return NO_ERROR; -out_no_minor_idr: +out_idr_remove_minor: + idr_remove(&minors, minor_got); +out_idr_remove_vol: + idr_remove(&tconn->volumes, vnr_got); + synchronize_rcu(); +out_no_vol_idr: kfree(mdev->current_epoch); out_no_epoch: drbd_bm_cleanup(mdev); @@ -2418,8 +2426,6 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, out_no_disk: blk_cleanup_queue(q); out_no_q: - idr_remove(&tconn->volumes, vnr_got); -out_no_idr: kfree(mdev); return ERR_NOMEM; } -- GitLab