On 11/19/2019 07:42 PM, Ilya Dryomov wrote:
On Tue, Nov 19, 2019 at 9:38 AM Dongsheng Yang
<dongsheng.yang@xxxxxxxxxxxx> wrote:
On 11/18/2019 09:38 PM, Ilya Dryomov wrote:
With exclusive lock out of the way, watch is the only thing left that
prevents a read-only mapping from being used with read-only OSD caps.
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
---
drivers/block/rbd.c | 41 +++++++++++++++++++++++++++--------------
1 file changed, 27 insertions(+), 14 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index aaa359561356..bfff195e8e23 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -6985,6 +6985,24 @@ static int rbd_dev_header_name(struct rbd_device *rbd_dev)
return ret;
}
+static void rbd_print_dne(struct rbd_device *rbd_dev, bool is_snap)
+{
+ if (!is_snap) {
+ pr_info("image %s/%s%s%s does not exist\n",
+ rbd_dev->spec->pool_name,
+ rbd_dev->spec->pool_ns ?: "",
+ rbd_dev->spec->pool_ns ? "/" : "",
+ rbd_dev->spec->image_name);
+ } else {
+ pr_info("snap %s/%s%s%s@%s does not exist\n",
+ rbd_dev->spec->pool_name,
+ rbd_dev->spec->pool_ns ?: "",
+ rbd_dev->spec->pool_ns ? "/" : "",
+ rbd_dev->spec->image_name,
+ rbd_dev->spec->snap_name);
+ }
+}
+
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
rbd_dev_unprobe(rbd_dev);
@@ -7003,6 +7021,7 @@ static void rbd_dev_image_release(struct rbd_device *rbd_dev)
*/
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
{
+ bool need_watch = !depth && !rbd_is_ro(rbd_dev);
int ret;
/*
@@ -7019,22 +7038,21 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
if (ret)
goto err_out_format;
- if (!depth) {
+ if (need_watch) {
ret = rbd_register_watch(rbd_dev);
if (ret) {
if (ret == -ENOENT)
- pr_info("image %s/%s%s%s does not exist\n",
- rbd_dev->spec->pool_name,
- rbd_dev->spec->pool_ns ?: "",
- rbd_dev->spec->pool_ns ? "/" : "",
- rbd_dev->spec->image_name);
+ rbd_print_dne(rbd_dev, false);
goto err_out_format;
}
}
ret = rbd_dev_header_info(rbd_dev);
- if (ret)
+ if (ret) {
+ if (ret == -ENOENT && !need_watch)
It's not just "if (ret == -ENOENT)" here, could you explain it more
about why we need "&& !need_watch"?
Just a mechanical transformation, I think.
There were two pr_infos before this patch, one for images and one for
snapshots. Because we don't call rbd_register_watch() in the read-only
case anymore, we need a second pr_info for images. One is "active" for
the normal case (need_watch), the other is "active" for the read-only
case (!need_watch).
Since only one ENOENT is expected, we could just "if (ret == -ENOENT)",
"&& !need_watch" isn't strictly needed.
Okey, thanx
+ rbd_print_dne(rbd_dev, false);
goto err_out_watch;
+ }
/*
* If this image is the one being mapped, we have pool name and
@@ -7048,12 +7066,7 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
ret = rbd_spec_fill_names(rbd_dev);
if (ret) {
if (ret == -ENOENT)
- pr_info("snap %s/%s%s%s@%s does not exist\n",
- rbd_dev->spec->pool_name,
- rbd_dev->spec->pool_ns ?: "",
- rbd_dev->spec->pool_ns ? "/" : "",
- rbd_dev->spec->image_name,
- rbd_dev->spec->snap_name);
+ rbd_print_dne(rbd_dev, true);
is_snap here is always true? IIUC, as we have a watcher for non-snap
mapping, the rbd_spec_fill_snap_id()
would not be fail with -ENOENT. Is that the reason? If so, can we add an
rbd_assert(depth); and add
a comment about why we use is_snap == true here?
I don't think we need an assert here. This just wraps the pr_info that
has been there for years, no other change is made.
Okey, let's keep this logic.
Thanks,
Ilya
