| Message ID | 20210927220039.1064193-4-mcgrof@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: second batch of add_disk() error handling conversions | expand |
On Mon, Sep 27, 2021 at 03:00:32PM -0700, Luis Chamberlain wrote: > + /* > + * test_and_set_bit() is used because it is protecting against two nvme > + * paths simultaneously calling device_add_disk() on the same namespace > + * head. > + */ > if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { > - device_add_disk(&head->subsys->dev, head->disk, > - nvme_ns_id_attr_groups); > + rc = device_add_disk(&head->subsys->dev, head->disk, > + nvme_ns_id_attr_groups); > + if (rc) > + return; > + set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags); No need to set_bit() here since the test_and_set_bit() already took care of that.
On 9/28/21 12:00 AM, Luis Chamberlain wrote: > We never checked for errors on add_disk() as this function > returned void. Now that this is fixed, use the shiny new > error handling. > > Since we now can tell for sure when a disk was added, move > setting the bit NVME_NSHEAD_DISK_LIVE only when we did > add the disk successfully. > > Nothing to do here as the cleanup is done elsewhere. We take > care and use test_and_set_bit() because it is protects against > two nvme paths simultaneously calling device_add_disk() on the > same namespace head. > > Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> > --- > drivers/nvme/host/multipath.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c > index e8ccdd398f78..35cace4f3f5f 100644 > --- a/drivers/nvme/host/multipath.c > +++ b/drivers/nvme/host/multipath.c > @@ -496,13 +496,22 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) > static void nvme_mpath_set_live(struct nvme_ns *ns) > { > struct nvme_ns_head *head = ns->head; > + int rc; > > if (!head->disk) > return; > > + /* > + * test_and_set_bit() is used because it is protecting against two nvme > + * paths simultaneously calling device_add_disk() on the same namespace > + * head. > + */ > if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { > - device_add_disk(&head->subsys->dev, head->disk, > - nvme_ns_id_attr_groups); > + rc = device_add_disk(&head->subsys->dev, head->disk, > + nvme_ns_id_attr_groups); > + if (rc) > + return; > + set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags); > nvme_add_ns_head_cdev(head); > } > > Errm. Setting the same bit twice? And shouldn't you unset the bit if 'device_add_disk()' fails? Cheers, Hannes
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index e8ccdd398f78..35cace4f3f5f 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -496,13 +496,22 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) static void nvme_mpath_set_live(struct nvme_ns *ns) { struct nvme_ns_head *head = ns->head; + int rc; if (!head->disk) return; + /* + * test_and_set_bit() is used because it is protecting against two nvme + * paths simultaneously calling device_add_disk() on the same namespace + * head. + */ if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { - device_add_disk(&head->subsys->dev, head->disk, - nvme_ns_id_attr_groups); + rc = device_add_disk(&head->subsys->dev, head->disk, + nvme_ns_id_attr_groups); + if (rc) + return; + set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags); nvme_add_ns_head_cdev(head); }
We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. Since we now can tell for sure when a disk was added, move setting the bit NVME_NSHEAD_DISK_LIVE only when we did add the disk successfully. Nothing to do here as the cleanup is done elsewhere. We take care and use test_and_set_bit() because it is protects against two nvme paths simultaneously calling device_add_disk() on the same namespace head. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> --- drivers/nvme/host/multipath.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)