linux-kernel - [PATCH 1/4] lightnvm: double-clear of dev->lun

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Date:   Fri,  7 Apr 2017 20:31:11 +0200
From:   "Javier González" <jg@...htnvm.io>
To:     mb@...htnvm.io
Cc:     linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        Javier González <javier@...xlabs.com>,
        Matias Bjørling <matias@...xlabs.com>
Subject: [PATCH 1/4] lightnvm: double-clear of dev->lun_map on target init error

The dev->lun_map bits are cleared twice if an target init error occurs.
First in the target clean routine, and then next in the nvm_tgt_create
error function. Make sure that it is only cleared once by extending
nvm_remove_tgt_devi() with a clear bit, such that clearing of bits can
ignored when cleaning up a successful initialized target.

Signed-off-by: Javier González <javier@...xlabs.com>
Signed-off-by: Matias Bjørling <matias@...xlabs.com>
---
 drivers/lightnvm/core.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 2122922..da4c082 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -89,7 +89,7 @@ static void nvm_release_luns_err(struct nvm_dev *dev, int lun_begin,
 		WARN_ON(!test_and_clear_bit(i, dev->lun_map));
 }
 
-static void nvm_remove_tgt_dev(struct nvm_tgt_dev *tgt_dev)
+static void nvm_remove_tgt_dev(struct nvm_tgt_dev *tgt_dev, int clear)
 {
 	struct nvm_dev *dev = tgt_dev->parent;
 	struct nvm_dev_map *dev_map = tgt_dev->map;
@@ -100,11 +100,13 @@ static void nvm_remove_tgt_dev(struct nvm_tgt_dev *tgt_dev)
 		int *lun_offs = ch_map->lun_offs;
 		int ch = i + ch_map->ch_off;
 
-		for (j = 0; j < ch_map->nr_luns; j++) {
-			int lun = j + lun_offs[j];
-			int lunid = (ch * dev->geo.luns_per_chnl) + lun;
+		if (clear) {
+			for (j = 0; j < ch_map->nr_luns; j++) {
+				int lun = j + lun_offs[j];
+				int lunid = (ch * dev->geo.luns_per_chnl) + lun;
 
-			WARN_ON(!test_and_clear_bit(lunid, dev->lun_map));
+				WARN_ON(!test_and_clear_bit(lunid, dev->lun_map));
+			}
 		}
 
 		kfree(ch_map->lun_offs);
@@ -309,7 +311,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
 err_queue:
 	blk_cleanup_queue(tqueue);
 err_dev:
-	nvm_remove_tgt_dev(tgt_dev);
+	nvm_remove_tgt_dev(tgt_dev, 0);
 err_t:
 	kfree(t);
 err_reserve:
@@ -332,7 +334,7 @@ static void __nvm_remove_target(struct nvm_target *t)
 	if (tt->exit)
 		tt->exit(tdisk->private_data);
 
-	nvm_remove_tgt_dev(t->dev);
+	nvm_remove_tgt_dev(t->dev, 1);
 	put_disk(tdisk);
 
 	list_del(&t->list);
-- 
2.7.4