Hi I'm sorry for subject with Re. I will send it again. On 2020/8/18 21:11, lixiaokeng wrote: > When one iscsi device logs in and logs out with the "multipath -r" > executed at the same time, memory leak happens in multipathd > process. > > The reason is following. When "multipath -r" is executed, the path > will be free in configure function. Before path_discovery executed, > iscsi device logs out. Then path_discovery will not find any path and > there is no path in the gvecs->pathvec. When map_discovery function > is executed, disassemble_map function will be called. Because > gvecs->pathvec->slot is empty and is_deamon is 1, a path will be > allocated and is not stored in gvecs->pathvec but store in > mpp->pg. But when the mpp is removed and freed by remove_map > function, the path will not be free and can't be find anymore. > > The procedure details given as follows, > 1."multipath -r" is executed > main > ->child > ->reconfigure > ->configure > ->path_discovery //after iscsi logout > ->map_discovery > ->update_multipath_table > ->disassemble_map > ->alloc_path > 2.then "multipath -r" is executed again > main > main > ->child > ->reconfigure > ->remove_maps_and_stop_waiters > ->remove_maps > > If checking is_deamon is deleted, there are many other things need be done like in > https://www.redhat.com/archives/dm-devel/2020-July/msg00245.html. And this > branch develops from 0.8.3 but upstream_queue is mainline which develops from > 0.8.4. > Here, we skip alloc_path if pp isn't find in pathvec and process is daemon. In > daemon, we should not store path with incomplete information to pathvec. The > pathvec stores all paths in daemon, so it is reasonable keep same with pathvec. > > Reported-by: Tianxiong Li <lutianxiong@xxxxxxxxxx> > Signed-off-by: Lixiaokeng <lixiaokeng@xxxxxxxxxx> > Signed-off-by: Zhiqiang Liu <liuzhiqiang26@xxxxxxxxxx> > --- > libmultipath/dmparser.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c > index f02c551..0f370e9 100644 > --- a/libmultipath/dmparser.c > +++ b/libmultipath/dmparser.c > @@ -314,6 +314,16 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp, > } > > if (!pp) { > + /* daemon should keep same with pathvec */ > + /* pp is not find in pathvec, skip it */ > + if (is_daemon) { > + FREE(word); > + for (k = 0; k < num_paths_args; k++) { > + p += get_word(p, NULL); > + } > + continue; > + } > + > pp_unfound = 1; > pp = alloc_path(); > > @@ -326,8 +336,8 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp, > strncpy(pp->wwid, mpp->wwid, > WWID_SIZE - 1); > } > - /* Only call this in multipath client mode */ > - if (!is_daemon && store_path(pathvec, pp)) { > + > + if (store_path(pathvec, pp)) { > free_path(pp); > goto out1; > } > -- > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
