diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/infiniband/core/cache.c | 484 | ||||
-rw-r--r-- | drivers/infiniband/core/sysfs.c | 18 |
2 files changed, 268 insertions, 234 deletions
diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c index e03eaf0c7527..045ca11fa135 100644 --- a/drivers/infiniband/core/cache.c +++ b/drivers/infiniband/core/cache.c @@ -59,8 +59,6 @@ struct ib_update_work { union ib_gid zgid; EXPORT_SYMBOL(zgid); -static const struct ib_gid_attr zattr; - enum gid_attr_find_mask { GID_ATTR_FIND_MASK_GID = 1UL << 0, GID_ATTR_FIND_MASK_NETDEV = 1UL << 1, @@ -73,15 +71,6 @@ enum gid_table_entry_props { GID_TABLE_ENTRY_DEFAULT = 1UL << 1, }; -enum gid_table_write_action { - GID_TABLE_WRITE_ACTION_ADD, - GID_TABLE_WRITE_ACTION_DEL, - /* MODIFY only updates the GID table. Currently only used by - * ib_cache_update. - */ - GID_TABLE_WRITE_ACTION_MODIFY -}; - struct ib_gid_table_entry { unsigned long props; union ib_gid gid; @@ -100,16 +89,13 @@ struct ib_gid_table { * (a) Find the GID * (b) Delete it. * - * Add/delete should be carried out atomically. - * This is done by locking this mutex from multiple - * writers. We don't need this lock for IB, as the MAD - * layer replaces all entries. All data_vec entries - * are locked by this lock. **/ - struct mutex lock; - /* This lock protects the table entries from being - * read and written simultaneously. + /* Any writer to data_vec must hold this lock and the write side of + * rwlock. readers must hold only rwlock. All writers must be in a + * sleepable context. */ + struct mutex lock; + /* rwlock protects data_vec[ix]->props. */ rwlock_t rwlock; struct ib_gid_table_entry *data_vec; }; @@ -163,94 +149,128 @@ int ib_cache_gid_parse_type_str(const char *buf) } EXPORT_SYMBOL(ib_cache_gid_parse_type_str); -/* This function expects that rwlock will be write locked in all - * scenarios and that lock will be locked in sleep-able (RoCE) - * scenarios. - */ -static int write_gid(struct ib_device *ib_dev, u8 port, - struct ib_gid_table *table, int ix, - const union ib_gid *gid, - const struct ib_gid_attr *attr, - enum gid_table_write_action action, - bool default_gid) - __releases(&table->rwlock) __acquires(&table->rwlock) +static void del_roce_gid(struct ib_device *device, u8 port_num, + struct ib_gid_table *table, int ix) { - int ret = 0; - struct net_device *old_net_dev; - enum ib_gid_type old_gid_type; + pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__, + device->name, port_num, ix, + table->data_vec[ix].gid.raw); + + if (rdma_cap_roce_gid_table(device, port_num)) + device->del_gid(device, port_num, ix, + &table->data_vec[ix].context); + dev_put(table->data_vec[ix].attr.ndev); +} - /* in rdma_cap_roce_gid_table, this funciton should be protected by a - * sleep-able lock. - */ +static int add_roce_gid(struct ib_gid_table *table, + const union ib_gid *gid, + const struct ib_gid_attr *attr) +{ + struct ib_gid_table_entry *entry; + int ix = attr->index; + int ret = 0; - if (rdma_cap_roce_gid_table(ib_dev, port)) { - table->data_vec[ix].props |= GID_TABLE_ENTRY_INVALID; - write_unlock_irq(&table->rwlock); - /* GID_TABLE_WRITE_ACTION_MODIFY currently isn't supported by - * RoCE providers and thus only updates the cache. - */ - if (action == GID_TABLE_WRITE_ACTION_ADD) - ret = ib_dev->add_gid(ib_dev, port, ix, gid, attr, - &table->data_vec[ix].context); - else if (action == GID_TABLE_WRITE_ACTION_DEL) - ret = ib_dev->del_gid(ib_dev, port, ix, - &table->data_vec[ix].context); - write_lock_irq(&table->rwlock); + if (!attr->ndev) { + pr_err("%s NULL netdev device=%s port=%d index=%d\n", + __func__, attr->device->name, attr->port_num, + attr->index); + return -EINVAL; } - old_net_dev = table->data_vec[ix].attr.ndev; - old_gid_type = table->data_vec[ix].attr.gid_type; - if (old_net_dev && old_net_dev != attr->ndev) - dev_put(old_net_dev); - /* if modify_gid failed, just delete the old gid */ - if (ret || action == GID_TABLE_WRITE_ACTION_DEL) { - gid = &zgid; - attr = &zattr; - table->data_vec[ix].context = NULL; + entry = &table->data_vec[ix]; + if ((entry->props & GID_TABLE_ENTRY_INVALID) == 0) { + WARN(1, "GID table corruption device=%s port=%d index=%d\n", + attr->device->name, attr->port_num, + attr->index); + return -EINVAL; } - memcpy(&table->data_vec[ix].gid, gid, sizeof(*gid)); - memcpy(&table->data_vec[ix].attr, attr, sizeof(*attr)); - if (default_gid) { - table->data_vec[ix].props |= GID_TABLE_ENTRY_DEFAULT; - if (action == GID_TABLE_WRITE_ACTION_DEL) - table->data_vec[ix].attr.gid_type = old_gid_type; + if (rdma_cap_roce_gid_table(attr->device, attr->port_num)) { + ret = attr->device->add_gid(attr->device, attr->port_num, + ix, gid, attr, &entry->context); + if (ret) { + pr_err("%s GID add failed device=%s port=%d index=%d\n", + __func__, attr->device->name, attr->port_num, + attr->index); + goto add_err; + } } - if (table->data_vec[ix].attr.ndev && - table->data_vec[ix].attr.ndev != old_net_dev) - dev_hold(table->data_vec[ix].attr.ndev); - - table->data_vec[ix].props &= ~GID_TABLE_ENTRY_INVALID; + dev_hold(attr->ndev); +add_err: + if (!ret) + pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__, + attr->device->name, attr->port_num, ix, gid->raw); return ret; } -static int add_gid(struct ib_device *ib_dev, u8 port, - struct ib_gid_table *table, int ix, - const union ib_gid *gid, - const struct ib_gid_attr *attr, - bool default_gid) { - return write_gid(ib_dev, port, table, ix, gid, attr, - GID_TABLE_WRITE_ACTION_ADD, default_gid); -} +/** + * add_modify_gid - Add or modify GID table entry + * + * @table: GID table in which GID to be added or modified + * @gid: GID content + * @attr: Attributes of the GID + * + * Returns 0 on success or appropriate error code. It accepts zero + * GID addition for non RoCE ports for HCA's who report them as valid + * GID. However such zero GIDs are not added to the cache. + */ +static int add_modify_gid(struct ib_gid_table *table, + const union ib_gid *gid, + const struct ib_gid_attr *attr) +{ + int ret; + + if (rdma_protocol_roce(attr->device, attr->port_num)) { + ret = add_roce_gid(table, gid, attr); + if (ret) + return ret; + } else { + /* + * Some HCA's report multiple GID entries with only one + * valid GID, but remaining as zero GID. + * So ignore such behavior for IB link layer and don't + * fail the call, but don't add such entry to GID cache. + */ + if (!memcmp(gid, &zgid, sizeof(*gid))) + return 0; + } + + lockdep_assert_held(&table->lock); + memcpy(&table->data_vec[attr->index].gid, gid, sizeof(*gid)); + memcpy(&table->data_vec[attr->index].attr, attr, sizeof(*attr)); -static int modify_gid(struct ib_device *ib_dev, u8 port, - struct ib_gid_table *table, int ix, - const union ib_gid *gid, - const struct ib_gid_attr *attr, - bool default_gid) { - return write_gid(ib_dev, port, table, ix, gid, attr, - GID_TABLE_WRITE_ACTION_MODIFY, default_gid); + write_lock_irq(&table->rwlock); + table->data_vec[attr->index].props &= ~GID_TABLE_ENTRY_INVALID; + write_unlock_irq(&table->rwlock); + return 0; } -static int del_gid(struct ib_device *ib_dev, u8 port, - struct ib_gid_table *table, int ix, - bool default_gid) { - return write_gid(ib_dev, port, table, ix, &zgid, &zattr, - GID_TABLE_WRITE_ACTION_DEL, default_gid); +/** + * del_gid - Delete GID table entry + * + * @ib_dev: IB device whose GID entry to be deleted + * @port: Port number of the IB device + * @table: GID table of the IB device for a port + * @ix: GID entry index to delete + * + */ +static void del_gid(struct ib_device *ib_dev, u8 port, + struct ib_gid_table *table, int ix) +{ + lockdep_assert_held(&table->lock); + write_lock_irq(&table->rwlock); + table->data_vec[ix].props |= GID_TABLE_ENTRY_INVALID; + write_unlock_irq(&table->rwlock); + + if (rdma_protocol_roce(ib_dev, port)) + del_roce_gid(ib_dev, port, table, ix); + memcpy(&table->data_vec[ix].gid, &zgid, sizeof(zgid)); + memset(&table->data_vec[ix].attr, 0, sizeof(table->data_vec[ix].attr)); + table->data_vec[ix].context = NULL; } -/* rwlock should be read locked */ +/* rwlock should be read locked, or lock should be held */ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid, const struct ib_gid_attr *val, bool default_gid, unsigned long mask, int *pempty) @@ -266,15 +286,32 @@ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid, i++; + /* find_gid() is used during GID addition where it is expected + * to return a free entry slot which is not duplicate. + * Free entry slot is requested and returned if pempty is set, + * so lookup free slot only if requested. + */ + if (pempty && empty < 0) { + if (data->props & GID_TABLE_ENTRY_INVALID) { + /* Found an invalid (free) entry; allocate it */ + if (data->props & GID_TABLE_ENTRY_DEFAULT) { + if (default_gid) + empty = curr_index; + } else { + empty = curr_index; + } + } + } + + /* + * Additionally find_gid() is used to find valid entry during + * lookup operation, where validity needs to be checked. So + * find the empty entry first to continue to search for a free + * slot and ignore its INVALID flag. + */ if (data->props & GID_TABLE_ENTRY_INVALID) continue; - if (empty < 0) - if (!memcmp(&data->gid, &zgid, sizeof(*gid)) && - !memcmp(attr, &zattr, sizeof(*attr)) && - !data->props) - empty = curr_index; - if (found >= 0) continue; @@ -310,20 +347,56 @@ static void make_default_gid(struct net_device *dev, union ib_gid *gid) addrconf_ifid_eui48(&gid->raw[8], dev); } -int ib_cache_gid_add(struct ib_device *ib_dev, u8 port, - union ib_gid *gid, struct ib_gid_attr *attr) +static int __ib_cache_gid_add(struct ib_device *ib_dev, u8 port, + union ib_gid *gid, struct ib_gid_attr *attr, + unsigned long mask, bool default_gid) { struct ib_gid_table *table; - int ix; int ret = 0; - struct net_device *idev; int empty; + int ix; - table = ib_dev->cache.ports[port - rdma_start_port(ib_dev)].gid; - + /* Do not allow adding zero GID in support of + * IB spec version 1.3 section 4.1.1 point (6) and + * section 12.7.10 and section 12.7.20 + */ if (!memcmp(gid, &zgid, sizeof(*gid))) return -EINVAL; + table = ib_dev->cache.ports[port - rdma_start_port(ib_dev)].gid; + + mutex_lock(&table->lock); + + ix = find_gid(table, gid, attr, default_gid, mask, &empty); + if (ix >= 0) + goto out_unlock; + + if (empty < 0) { + ret = -ENOSPC; + goto out_unlock; + } + attr->device = ib_dev; + attr->index = empty; + attr->port_num = port; + ret = add_modify_gid(table, gid, attr); + if (!ret) + dispatch_gid_change_event(ib_dev, port); + +out_unlock: + mutex_unlock(&table->lock); + if (ret) + pr_warn("%s: unable to add gid %pI6 error=%d\n", + __func__, gid->raw, ret); + return ret; +} + +int ib_cache_gid_add(struct ib_device *ib_dev, u8 port, + union ib_gid *gid, struct ib_gid_attr *attr) +{ + struct net_device *idev; + unsigned long mask; + int ret; + if (ib_dev->get_netdev) { idev = ib_dev->get_netdev(ib_dev, port); if (idev && attr->ndev != idev) { @@ -340,27 +413,11 @@ int ib_cache_gid_add(struct ib_device *ib_dev, u8 port, dev_put(idev); } - mutex_lock(&table->lock); - write_lock_irq(&table->rwlock); - - ix = find_gid(table, gid, attr, false, GID_ATTR_FIND_MASK_GID | - GID_ATTR_FIND_MASK_GID_TYPE | - GID_ATTR_FIND_MASK_NETDEV, &empty); - if (ix >= 0) - goto out_unlock; - - if (empty < 0) { - ret = -ENOSPC; - goto out_unlock; - } - - ret = add_gid(ib_dev, port, table, empty, gid, attr, false); - if (!ret) - dispatch_gid_change_event(ib_dev, port); + mask = GID_ATTR_FIND_MASK_GID | + GID_ATTR_FIND_MASK_GID_TYPE | + GID_ATTR_FIND_MASK_NETDEV; -out_unlock: - write_unlock_irq(&table->rwlock); - mutex_unlock(&table->lock); + ret = __ib_cache_gid_add(ib_dev, port, gid, attr, mask, false); return ret; } @@ -368,29 +425,32 @@ int ib_cache_gid_del(struct ib_device *ib_dev, u8 port, union ib_gid *gid, struct ib_gid_attr *attr) { struct ib_gid_table *table; + int ret = 0; int ix; table = ib_dev->cache.ports[port - rdma_start_port(ib_dev)].gid; mutex_lock(&table->lock); - write_lock_irq(&table->rwlock); ix = find_gid(table, gid, attr, false, GID_ATTR_FIND_MASK_GID | GID_ATTR_FIND_MASK_GID_TYPE | - GID_ATTR_FIND_MASK_NETDEV | - GID_ATTR_FIND_MASK_DEFAULT, + GID_ATTR_FIND_MASK_NETDEV, NULL); - if (ix < 0) + if (ix < 0) { + ret = -EINVAL; goto out_unlock; + } - if (!del_gid(ib_dev, port, table, ix, false)) - dispatch_gid_change_event(ib_dev, port); + del_gid(ib_dev, port, table, ix); + dispatch_gid_change_event(ib_dev, port); out_unlock: - write_unlock_irq(&table->rwlock); mutex_unlock(&table->lock); - return 0; + if (ret) + pr_debug("%s: can't delete gid %pI6 error=%d\n", + __func__, gid->raw, ret); + return ret; } int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u8 port, @@ -403,16 +463,14 @@ int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u8 port, table = ib_dev->cache.ports[port - rdma_start_port(ib_dev)].gid; mutex_lock(&table->lock); - write_lock_irq(&table->rwlock); - for (ix = 0; ix < table->sz; ix++) - if (table->data_vec[ix].attr.ndev == ndev) - if (!del_gid(ib_dev, port, table, ix, - !!(table->data_vec[ix].props & - GID_TABLE_ENTRY_DEFAULT))) - deleted = true; + for (ix = 0; ix < table->sz; ix++) { + if (table->data_vec[ix].attr.ndev == ndev) { + del_gid(ib_dev, port, table, ix); + deleted = true; + } + } - write_unlock_irq(&table->rwlock); mutex_unlock(&table->lock); if (deleted) @@ -609,6 +667,7 @@ static struct ib_gid_table *alloc_gid_table(int sz) { struct ib_gid_table *table = kzalloc(sizeof(struct ib_gid_table), GFP_KERNEL); + int i; if (!table) return NULL; @@ -622,6 +681,11 @@ static struct ib_gid_table *alloc_gid_table(int sz) table->sz = sz; rwlock_init(&table->rwlock); + /* Mark all entries as invalid so that allocator can allocate + * one of the invalid (free) entry. + */ + for (i = 0; i < sz; i++) + table->data_vec[i].props |= GID_TABLE_ENTRY_INVALID; return table; err_free_table: @@ -646,16 +710,15 @@ static void cleanup_gid_table_port(struct ib_device *ib_dev, u8 port, if (!table) return; - write_lock_irq(&table->rwlock); + mutex_lock(&table->lock); for (i = 0; i < table->sz; ++i) { if (memcmp(&table->data_vec[i].gid, &zgid, - sizeof(table->data_vec[i].gid))) - if (!del_gid(ib_dev, port, table, i, - table->data_vec[i].props & - GID_ATTR_FIND_MASK_DEFAULT)) - deleted = true; + sizeof(table->data_vec[i].gid))) { + del_gid(ib_dev, port, table, i); + deleted = true; + } } - write_unlock_irq(&table->rwlock); + mutex_unlock(&table->lock); if (deleted) dispatch_gid_change_event(ib_dev, port); @@ -668,9 +731,9 @@ void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port, { union ib_gid gid; struct ib_gid_attr gid_attr; - struct ib_gid_attr zattr_type = zattr; struct ib_gid_table *table; unsigned int gid_type; + unsigned long mask; table = ib_dev->cache.ports[port - rdma_start_port(ib_dev)].gid; @@ -679,60 +742,19 @@ void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port, gid_attr.ndev = ndev; for (gid_type = 0; gid_type < IB_GID_TYPE_SIZE; ++gid_type) { - int ix; - union ib_gid current_gid; - struct ib_gid_attr current_gid_attr = {}; - if (1UL << gid_type & ~gid_type_mask) continue; gid_attr.gid_type = gid_type; - mutex_lock(&table->lock); - write_lock_irq(&table->rwlock); - ix = find_gid(table, NULL, &gid_attr, true, - GID_ATTR_FIND_MASK_GID_TYPE | - GID_ATTR_FIND_MASK_DEFAULT, - NULL); - - /* Coudn't find default GID location */ - if (WARN_ON(ix < 0)) - goto release; - - zattr_type.gid_type = gid_type; - - if (!__ib_cache_gid_get(ib_dev, port, ix, - ¤t_gid, ¤t_gid_attr) && - mode == IB_CACHE_GID_DEFAULT_MODE_SET && - !memcmp(&gid, ¤t_gid, sizeof(gid)) && - !memcmp(&gid_attr, ¤t_gid_attr, sizeof(gid_attr))) - goto release; - - if (memcmp(¤t_gid, &zgid, sizeof(current_gid)) || - memcmp(¤t_gid_attr, &zattr_type, - sizeof(current_gid_attr))) { - if (del_gid(ib_dev, port, table, ix, true)) { - pr_warn("ib_cache_gid: can't delete index %d for default gid %pI6\n", - ix, gid.raw); - goto release; - } else { - dispatch_gid_change_event(ib_dev, port); - } - } - if (mode == IB_CACHE_GID_DEFAULT_MODE_SET) { - if (add_gid(ib_dev, port, table, ix, &gid, &gid_attr, true)) - pr_warn("ib_cache_gid: unable to add default gid %pI6\n", - gid.raw); - else - dispatch_gid_change_event(ib_dev, port); + mask = GID_ATTR_FIND_MASK_GID_TYPE | + GID_ATTR_FIND_MASK_DEFAULT; + __ib_cache_gid_add(ib_dev, port, &gid, + &gid_attr, mask, true); + } else if (mode == IB_CACHE_GID_DEFAULT_MODE_DELETE) { + ib_cache_gid_del(ib_dev, port, &gid, &gid_attr); } - -release: - if (current_gid_attr.ndev) - dev_put(current_gid_attr.ndev); - write_unlock_irq(&table->rwlock); - mutex_unlock(&table->lock); } } @@ -1057,25 +1079,50 @@ int ib_get_cached_port_state(struct ib_device *device, } EXPORT_SYMBOL(ib_get_cached_port_state); +static int config_non_roce_gid_cache(struct ib_device *device, + u8 port, int gid_tbl_len) +{ + struct ib_gid_attr gid_attr = {}; + struct ib_gid_table *table; + union ib_gid gid; + int ret = 0; + int i; + + gid_attr.device = device; + gid_attr.port_num = port; + table = device->cache.ports[port - rdma_start_port(device)].gid; + + mutex_lock(&table->lock); + for (i = 0; i < gid_tbl_len; ++i) { + if (!device->query_gid) + continue; + ret = device->query_gid(device, port, i, &gid); + if (ret) { + pr_warn("query_gid failed (%d) for %s (index %d)\n", + ret, device->name, i); + goto err; + } + gid_attr.index = i; + add_modify_gid(table, &gid, &gid_attr); + } +err: + mutex_unlock(&table->lock); + return ret; +} + static void ib_cache_update(struct ib_device *device, u8 port, bool enforce_security) { struct ib_port_attr *tprops = NULL; struct ib_pkey_cache *pkey_cache = NULL, *old_pkey_cache; - struct ib_gid_cache { - int table_len; - union ib_gid table[0]; - } *gid_cache = NULL; int i; int ret; struct ib_gid_table *table; - bool use_roce_gid_table; if (!rdma_is_port_valid(device, port)) return; - use_roce_gid_table = rdma_protocol_roce(device, port); table = device->cache.ports[port - rdma_start_port(device)].gid; tprops = kmalloc(sizeof *tprops, GFP_KERNEL); @@ -1089,6 +1136,13 @@ static void ib_cache_update(struct ib_device *device, goto err; } + if (!rdma_protocol_roce(device, port)) { + ret = config_non_roce_gid_cache(device, port, + tprops->gid_tbl_len); + if (ret) + goto err; + } + pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len * sizeof *pkey_cache->table, GFP_KERNEL); if (!pkey_cache) @@ -1096,15 +1150,6 @@ static void ib_cache_update(struct ib_device *device, pkey_cache->table_len = tprops->pkey_tbl_len; - if (!use_roce_gid_table) { - gid_cache = kmalloc(sizeof(*gid_cache) + tprops->gid_tbl_len * - sizeof(*gid_cache->table), GFP_KERNEL); - if (!gid_cache) - goto err; - - gid_cache->table_len = tprops->gid_tbl_len; - } - for (i = 0; i < pkey_cache->table_len; ++i) { ret = ib_query_pkey(device, port, i, pkey_cache->table + i); if (ret) { @@ -1114,33 +1159,12 @@ static void ib_cache_update(struct ib_device *device, } } - if (!use_roce_gid_table) { - for (i = 0; i < gid_cache->table_len; ++i) { - ret = device->query_gid(device, port, i, - gid_cache->table + i); - if (ret) { - pr_warn("ib_query_gid failed (%d) for %s (index %d)\n", - ret, device->name, i); - goto err; - } - } - } - write_lock_irq(&device->cache.lock); old_pkey_cache = device->cache.ports[port - rdma_start_port(device)].pkey; device->cache.ports[port - rdma_start_port(device)].pkey = pkey_cache; - if (!use_roce_gid_table) { - write_lock(&table->rwlock); - for (i = 0; i < gid_cache->table_len; i++) { - modify_gid(device, port, table, i, gid_cache->table + i, - &zattr, false); - } - write_unlock(&table->rwlock); - } - device->cache.ports[port - rdma_start_port(device)].lmc = tprops->lmc; device->cache.ports[port - rdma_start_port(device)].port_state = tprops->state; @@ -1154,14 +1178,12 @@ static void ib_cache_update(struct ib_device *device, port, tprops->subnet_prefix); - kfree(gid_cache); kfree(old_pkey_cache); kfree(tprops); return; err: kfree(pkey_cache); - kfree(gid_cache); kfree(tprops); } diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c index 9b0fbab41dc6..31c7efaf8e7a 100644 --- a/drivers/infiniband/core/sysfs.c +++ b/drivers/infiniband/core/sysfs.c @@ -389,14 +389,26 @@ static ssize_t show_port_gid(struct ib_port *p, struct port_attribute *attr, { struct port_table_attribute *tab_attr = container_of(attr, struct port_table_attribute, attr); + union ib_gid *pgid; union ib_gid gid; ssize_t ret; ret = ib_query_gid(p->ibdev, p->port_num, tab_attr->index, &gid, NULL); - if (ret) - return ret; - return sprintf(buf, "%pI6\n", gid.raw); + /* If reading GID fails, it is likely due to GID entry being empty + * (invalid) or reserved GID in the table. + * User space expects to read GID table entries as long as it given + * index is within GID table size. + * Administrative/debugging tool fails to query rest of the GID entries + * if it hits error while querying a GID of the given index. + * To avoid user space throwing such error on fail to read gid, return + * zero GID as before. This maintains backward compatibility. + */ + if (ret) + pgid = &zgid; + else + pgid = &gid; + return sprintf(buf, "%pI6\n", pgid->raw); } static ssize_t show_port_gid_attr_ndev(struct ib_port *p, |