From e714eb26fddc8768a8de279d1de3ffedab35929e Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Fri, 5 Mar 2021 21:40:57 -0600 Subject: [PATCH] libmultipath: check if user_friendly_name is in use If there are multipath devices that have user_friendly_names but do not have their bindings in the bindings_file, get_user_friendly_alias() can currently give out those names again. This can result in an incorrect entry in the bindings file, and a device that gets created with a WWID alias instead of a user_friendly_name. This situation can happen after the pivot root, if a multipath device is created in the initramfs. If this device doesn't have a binding in the regular filesystem bindings_file and a new multipath device is created before it can add its binding, the new device can steal that user_friendly_name during multipathd's initial configure. To solve this, get_user_friendly_alias() now calls lookup_binding() with a new paramter, telling it to check if the id it found is already in use by a diffent device. If so, lookup_binding() will continue to check open ids, until it finds one that it not currently in use by a dm device. --- libmultipath/alias.c | 48 +++++++++++++++++++++++++++++++++++++++++--- tests/alias.c | 22 ++++++++++---------- 2 files changed, 56 insertions(+), 14 deletions(-) diff --git a/libmultipath/alias.c b/libmultipath/alias.c index 14401cae..01f737f4 100644 --- a/libmultipath/alias.c +++ b/libmultipath/alias.c @@ -17,6 +17,7 @@ #include "vector.h" #include "checkers.h" #include "structs.h" +#include "devmapper.h" /* @@ -104,6 +105,28 @@ scan_devname(const char *alias, const char *prefix) return n; } +static int +id_already_taken(int id, const char *prefix, const char *map_wwid) +{ + char alias[LINE_MAX]; + + if (format_devname(alias, id, LINE_MAX, prefix) < 0) + return 0; + + if (dm_map_present(alias)) { + char wwid[WWID_SIZE]; + + /* If both the name and the wwid match, then it's fine.*/ + if (dm_get_uuid(alias, wwid, sizeof(wwid)) == 0 && + strncmp(map_wwid, wwid, sizeof(wwid)) == 0) + return 0; + condlog(3, "%s: alias '%s' already taken, but not in bindings file. reselecting alias", map_wwid, alias); + return 1; + } + return 0; +} + + /* * Returns: 0 if matching entry in WWIDs file found * -1 if an error occurs @@ -113,7 +136,7 @@ scan_devname(const char *alias, const char *prefix) */ static int lookup_binding(FILE *f, const char *map_wwid, char **map_alias, - const char *prefix) + const char *prefix, int check_if_taken) { char buf[LINE_MAX]; unsigned int line_nr = 0; @@ -168,12 +191,31 @@ lookup_binding(FILE *f, const char *map_wwid, char **map_alias, return 0; } } + if (!prefix && check_if_taken) + id = -1; if (id >= smallest_bigger_id) { if (biggest_id < INT_MAX) id = biggest_id + 1; else id = -1; } + if (id > 0 && check_if_taken) { + while(id_already_taken(id, prefix, map_wwid)) { + if (id == INT_MAX) { + id = -1; + break; + } + id++; + if (id == smallest_bigger_id) { + if (biggest_id == INT_MAX) { + id = -1; + break; + } + if (biggest_id >= smallest_bigger_id) + id = biggest_id + 1; + } + } + } if (id < 0) { condlog(0, "no more available user_friendly_names"); return -1; @@ -316,7 +358,7 @@ use_existing_alias (const char *wwid, const char *file, const char *alias_old, goto out; } - id = lookup_binding(f, wwid, &alias, NULL); + id = lookup_binding(f, wwid, &alias, NULL, 0); if (alias) { condlog(3, "Use existing binding [%s] for WWID [%s]", alias, wwid); @@ -373,7 +415,7 @@ get_user_friendly_alias(const char *wwid, const char *file, const char *prefix, return NULL; } - id = lookup_binding(f, wwid, &alias, prefix); + id = lookup_binding(f, wwid, &alias, prefix, 1); if (id < 0) { fclose(f); return NULL; diff --git a/tests/alias.c b/tests/alias.c index 30414db0..ab1a9325 100644 --- a/tests/alias.c +++ b/tests/alias.c @@ -356,7 +356,7 @@ static void lb_empty(void **state) will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID0] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID0", &alias, NULL); + rc = lookup_binding(NULL, "WWID0", &alias, NULL, 0); assert_int_equal(rc, 1); assert_ptr_equal(alias, NULL); } @@ -369,7 +369,7 @@ static void lb_match_a(void **state) will_return(__wrap_fgets, "MPATHa WWID0\n"); expect_condlog(3, "Found matching wwid [WWID0] in bindings file." " Setting alias to MPATHa\n"); - rc = lookup_binding(NULL, "WWID0", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID0", &alias, "MPATH", 0); assert_int_equal(rc, 0); assert_ptr_not_equal(alias, NULL); assert_string_equal(alias, "MPATHa"); @@ -384,7 +384,7 @@ static void lb_nomatch_a(void **state) will_return(__wrap_fgets, "MPATHa WWID0\n"); will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID1] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID1", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID1", &alias, "MPATH", 0); assert_int_equal(rc, 2); assert_ptr_equal(alias, NULL); } @@ -398,7 +398,7 @@ static void lb_match_c(void **state) will_return(__wrap_fgets, "MPATHc WWID1\n"); expect_condlog(3, "Found matching wwid [WWID1] in bindings file." " Setting alias to MPATHc\n"); - rc = lookup_binding(NULL, "WWID1", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID1", &alias, "MPATH", 0); assert_int_equal(rc, 0); assert_ptr_not_equal(alias, NULL); assert_string_equal(alias, "MPATHc"); @@ -414,7 +414,7 @@ static void lb_nomatch_a_c(void **state) will_return(__wrap_fgets, "MPATHc WWID1\n"); will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID2] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, 2); assert_ptr_equal(alias, NULL); } @@ -428,7 +428,7 @@ static void lb_nomatch_c_a(void **state) will_return(__wrap_fgets, "MPATHa WWID0\n"); will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID2] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, 2); assert_ptr_equal(alias, NULL); } @@ -443,7 +443,7 @@ static void lb_nomatch_a_b(void **state) will_return(__wrap_fgets, "MPATHb WWID1\n"); will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID2] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, 3); assert_ptr_equal(alias, NULL); } @@ -459,7 +459,7 @@ static void lb_nomatch_a_b_bad(void **state) will_return(__wrap_fgets, NULL); expect_condlog(3, "Ignoring malformed line 3 in bindings file\n"); expect_condlog(3, "No matching wwid [WWID2] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, 3); assert_ptr_equal(alias, NULL); } @@ -474,7 +474,7 @@ static void lb_nomatch_b_a(void **state) will_return(__wrap_fgets, "MPATHa WWID0\n"); will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID2] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, 27); assert_ptr_equal(alias, NULL); } @@ -490,7 +490,7 @@ static void lb_nomatch_int_max(void **state) will_return(__wrap_fgets, "MPATHa WWID0\n"); will_return(__wrap_fgets, NULL); expect_condlog(0, "no more available user_friendly_names\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, -1); assert_ptr_equal(alias, NULL); } @@ -505,7 +505,7 @@ static void lb_nomatch_int_max_m1(void **state) will_return(__wrap_fgets, "MPATHa WWID0\n"); will_return(__wrap_fgets, NULL); expect_condlog(3, "No matching wwid [WWID2] in bindings file.\n"); - rc = lookup_binding(NULL, "WWID2", &alias, "MPATH"); + rc = lookup_binding(NULL, "WWID2", &alias, "MPATH", 0); assert_int_equal(rc, INT_MAX); assert_ptr_equal(alias, NULL); } -- 2.17.2