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authorStefan Hajnoczi <stefanha@redhat.com>2018-07-31 15:32:46 +0100
committerDave Jiang <dave.jiang@intel.com>2018-07-31 17:05:42 -0700
commitb7751410c180a05fdc21268f8661b1480169b0df (patch)
treeec5c8bf369681268987df2866ee387e7946d51ca /drivers/dax
parentb4d4702f30e09ed1311e560334eb25fc2015c8ce (diff)
downloadlinux-b7751410c180a05fdc21268f8661b1480169b0df.tar.bz2
device-dax: avoid hang on error before devm_memremap_pages()
dax_pmem_percpu_exit() waits for dax_pmem_percpu_release() to invoke the dax_pmem->cmp completion. Unfortunately this approach to cleaning up the percpu_ref only works after devm_memremap_pages() was successful. If devm_add_action_or_reset() or devm_memremap_pages() fails, dax_pmem_percpu_release() is not invoked. Therefore dax_pmem_percpu_exit() hangs waiting for the completion: rc = devm_add_action_or_reset(dev, dax_pmem_percpu_exit, &dax_pmem->ref); if (rc) return rc; dax_pmem->pgmap.ref = &dax_pmem->ref; addr = devm_memremap_pages(dev, &dax_pmem->pgmap); Avoid the hang by calling percpu_ref_exit() in the error paths instead of going through dax_pmem_percpu_exit(). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Diffstat (limited to 'drivers/dax')
-rw-r--r--drivers/dax/pmem.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index fd49b24fd6af..99e2aace8078 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -105,15 +105,19 @@ static int dax_pmem_probe(struct device *dev)
if (rc)
return rc;
- rc = devm_add_action_or_reset(dev, dax_pmem_percpu_exit,
- &dax_pmem->ref);
- if (rc)
+ rc = devm_add_action(dev, dax_pmem_percpu_exit, &dax_pmem->ref);
+ if (rc) {
+ percpu_ref_exit(&dax_pmem->ref);
return rc;
+ }
dax_pmem->pgmap.ref = &dax_pmem->ref;
addr = devm_memremap_pages(dev, &dax_pmem->pgmap);
- if (IS_ERR(addr))
+ if (IS_ERR(addr)) {
+ devm_remove_action(dev, dax_pmem_percpu_exit, &dax_pmem->ref);
+ percpu_ref_exit(&dax_pmem->ref);
return PTR_ERR(addr);
+ }
rc = devm_add_action_or_reset(dev, dax_pmem_percpu_kill,
&dax_pmem->ref);