From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- net/ceph/string_table.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 net/ceph/string_table.c (limited to 'net/ceph/string_table.c') diff --git a/net/ceph/string_table.c b/net/ceph/string_table.c new file mode 100644 index 000000000..3191d9d16 --- /dev/null +++ b/net/ceph/string_table.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(string_tree_lock); +static struct rb_root string_tree = RB_ROOT; + +struct ceph_string *ceph_find_or_create_string(const char* str, size_t len) +{ + struct ceph_string *cs, *exist; + struct rb_node **p, *parent; + int ret; + + exist = NULL; + spin_lock(&string_tree_lock); + p = &string_tree.rb_node; + while (*p) { + exist = rb_entry(*p, struct ceph_string, node); + ret = ceph_compare_string(exist, str, len); + if (ret > 0) + p = &(*p)->rb_left; + else if (ret < 0) + p = &(*p)->rb_right; + else + break; + exist = NULL; + } + if (exist && !kref_get_unless_zero(&exist->kref)) { + rb_erase(&exist->node, &string_tree); + RB_CLEAR_NODE(&exist->node); + exist = NULL; + } + spin_unlock(&string_tree_lock); + if (exist) + return exist; + + cs = kmalloc(sizeof(*cs) + len + 1, GFP_NOFS); + if (!cs) + return NULL; + + kref_init(&cs->kref); + cs->len = len; + memcpy(cs->str, str, len); + cs->str[len] = 0; + +retry: + exist = NULL; + parent = NULL; + p = &string_tree.rb_node; + spin_lock(&string_tree_lock); + while (*p) { + parent = *p; + exist = rb_entry(*p, struct ceph_string, node); + ret = ceph_compare_string(exist, str, len); + if (ret > 0) + p = &(*p)->rb_left; + else if (ret < 0) + p = &(*p)->rb_right; + else + break; + exist = NULL; + } + ret = 0; + if (!exist) { + rb_link_node(&cs->node, parent, p); + rb_insert_color(&cs->node, &string_tree); + } else if (!kref_get_unless_zero(&exist->kref)) { + rb_erase(&exist->node, &string_tree); + RB_CLEAR_NODE(&exist->node); + ret = -EAGAIN; + } + spin_unlock(&string_tree_lock); + if (ret == -EAGAIN) + goto retry; + + if (exist) { + kfree(cs); + cs = exist; + } + + return cs; +} +EXPORT_SYMBOL(ceph_find_or_create_string); + +void ceph_release_string(struct kref *ref) +{ + struct ceph_string *cs = container_of(ref, struct ceph_string, kref); + + spin_lock(&string_tree_lock); + if (!RB_EMPTY_NODE(&cs->node)) { + rb_erase(&cs->node, &string_tree); + RB_CLEAR_NODE(&cs->node); + } + spin_unlock(&string_tree_lock); + + kfree_rcu(cs, rcu); +} +EXPORT_SYMBOL(ceph_release_string); + +bool ceph_strings_empty(void) +{ + return RB_EMPTY_ROOT(&string_tree); +} -- cgit v1.3.1