On 11/27/2018 03:24 PM, Javier Gonzalez wrote:

quoted

On 27 Nov 2018, at 15.22, Matias Bjørling [off-list ref] wrote:

On 11/27/2018 01:57 PM, Javier Gonzalez wrote:

quoted

quoted

On 27 Nov 2018, at 02.53, Hua Su [off-list ref] wrote:

Add lock protection for list operations.
Signed-off-by: Hua Su <redacted>
---
drivers/lightnvm/pblk-core.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 6944aac43b01..e490df217dac 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c

@@ -1286,24 +1286,27 @@ int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line)
    list_del(&line->list);

    ret = pblk_line_prepare(pblk, line);
-    if (ret) {
-        list_add(&line->list, &l_mg->free_list);
-        spin_unlock(&l_mg->free_lock);
-        return ret;
-    }
-    spin_unlock(&l_mg->free_lock);
+    if (ret)
+        goto out;

    ret = pblk_line_alloc_bitmaps(pblk, line);
    if (ret)
-        return ret;
+        goto out;

    if (!pblk_line_init_bb(pblk, line, 0)) {
        list_add(&line->list, &l_mg->free_list);
+        spin_unlock(&l_mg->free_lock);
        return -EINTR;
    }
+    spin_unlock(&l_mg->free_lock);

    pblk_rl_free_lines_dec(&pblk->rl, line, true);
    return 0;
+
+out:
+    list_add(&line->list, &l_mg->free_list);
+    spin_unlock(&l_mg->free_lock);
+    return ret;

}

void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line)
--
2.19.1

This path is only touched by the recovery path, which is single
threaded, so there is no race condition as is. Also, if recovery fails,
pblk will not create the instance at all. This said, it would be
good to protect the list_add on the pblk_line_init_bb() error path in
case this code is used for some other purpose in the future.

I like your explanation here. Another option is that we could add a comment to notify the developer that it safe in this context?

Sure. Do you want to add it? Or should I send it?

Javier

Please send it. Thanks!