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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2018-07-31 15:32:46 +0100 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2018-07-31 17:05:42 -0700 |
| commit | b7751410c180a05fdc21268f8661b1480169b0df (patch) | |
| tree | ec5c8bf369681268987df2866ee387e7946d51ca /drivers | |
| parent | b4d4702f30e09ed1311e560334eb25fc2015c8ce (diff) | |
| download | linux-stable-b7751410c180a05fdc21268f8661b1480169b0df.tar.gz linux-stable-b7751410c180a05fdc21268f8661b1480169b0df.tar.bz2 linux-stable-b7751410c180a05fdc21268f8661b1480169b0df.zip | |
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')
| -rw-r--r-- | drivers/dax/pmem.c | 12 |
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); |