| Message ID | 20241122211133.718861-12-bmarzins@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | multipath-tools: Handle tableless DM devices | expand |
On Fri, 2024-11-22 at 16:11 -0500, Benjamin Marzinski wrote: > If dm_get_opencount() fails, open_count will be negative, which means > mpath_in_use() will never fail. However, dm_flush_map__() will > eventually fail. There are multiple callers of dm_get_opencount() > that > run when trying to remove a device. All the others treat a failed > call > as if the device was in use, including one that will later be called > directly on this device. So save ourselves the work, and exit early > > Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Side note: I realize that there are other callers of dm_get_opencount() that take a negative return value for a "yes". That happens to be correct for the respective callers, but it's quite unclean. Your patch is fine though. Martin > --- > libmultipath/devmapper.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c > index 751b45d8..3667c51b 100644 > --- a/libmultipath/devmapper.c > +++ b/libmultipath/devmapper.c > @@ -961,6 +961,11 @@ int mpath_in_use(const char *name) > { > int open_count = dm_get_opencount(name); > > + if (open_count < 0) { > + condlog(0, "%s: %s: failed to get open count, > assuming in use", > + __func__, name); > + return 1; > + } > if (open_count) { > int part_count = 0; >
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c index 751b45d8..3667c51b 100644 --- a/libmultipath/devmapper.c +++ b/libmultipath/devmapper.c @@ -961,6 +961,11 @@ int mpath_in_use(const char *name) { int open_count = dm_get_opencount(name); + if (open_count < 0) { + condlog(0, "%s: %s: failed to get open count, assuming in use", + __func__, name); + return 1; + } if (open_count) { int part_count = 0;
If dm_get_opencount() fails, open_count will be negative, which means mpath_in_use() will never fail. However, dm_flush_map__() will eventually fail. There are multiple callers of dm_get_opencount() that run when trying to remove a device. All the others treat a failed call as if the device was in use, including one that will later be called directly on this device. So save ourselves the work, and exit early Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> --- libmultipath/devmapper.c | 5 +++++ 1 file changed, 5 insertions(+)