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([102.208.164.46]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45b6f306c22sm325019885e9.13.2025.09.03.05.20.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Sep 2025 05:20:27 -0700 (PDT) From: Erick Karanja To: tony.luck@intel.com, reinette.chatre@intel.com Cc: julia.lawall@inria.fr, Dave.Martin@arm.com, james.morse@arm.com, linux-kernel@vger.kernel.org, Erick Karanja Subject: [PATCH] fs/resctrl: Convert lock to guard Date: Wed, 3 Sep 2025 15:20:15 +0300 Message-ID: <20250903122017.1331877-1-karanja99erick@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Convert manual lock/unlock calls to guard and tidy up the code. Generated-by: Coccinelle SmPL Signed-off-by: Erick Karanja --- fs/resctrl/rdtgroup.c | 249 +++++++++++++++++++----------------------- 1 file changed, 113 insertions(+), 136 deletions(-) diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index 77d08229d855..3c81f1535dbb 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -916,14 +916,13 @@ int proc_resctrl_show(struct seq_file *s, struct pid_= namespace *ns, struct pid *pid, struct task_struct *tsk) { struct rdtgroup *rdtg; - int ret =3D 0; =20 - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); =20 /* Return empty if resctrl has not been mounted. */ if (!resctrl_mounted) { seq_puts(s, "res:\nmon:\n"); - goto unlock; + return 0; } =20 list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { @@ -952,17 +951,13 @@ int proc_resctrl_show(struct seq_file *s, struct pid_= namespace *ns, break; } seq_putc(s, '\n'); - goto unlock; + return 0; } /* * The above search should succeed. Otherwise return * with an error. */ - ret =3D -ENOENT; -unlock: - mutex_unlock(&rdtgroup_mutex); - - return ret; + return -ENOENT; } #endif =20 @@ -971,13 +966,12 @@ static int rdt_last_cmd_status_show(struct kernfs_ope= n_file *of, { int len; =20 - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); len =3D seq_buf_used(&last_cmd_status); if (len) seq_printf(seq, "%.*s", len, last_cmd_status_buf); else seq_puts(seq, "ok\n"); - mutex_unlock(&rdtgroup_mutex); return 0; } =20 @@ -1062,66 +1056,66 @@ static int rdt_bit_usage_show(struct kernfs_open_fi= le *of, u32 ctrl_val; =20 cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - hw_shareable =3D r->cache.shareable_bits; - list_for_each_entry(dom, &r->ctrl_domains, hdr.list) { - if (sep) - seq_putc(seq, ';'); - sw_shareable =3D 0; - exclusive =3D 0; - seq_printf(seq, "%d=3D", dom->hdr.id); - for (i =3D 0; i < closids_supported(); i++) { - if (!closid_allocated(i)) - continue; - ctrl_val =3D resctrl_arch_get_config(r, dom, i, - s->conf_type); - mode =3D rdtgroup_mode_by_closid(i); - switch (mode) { - case RDT_MODE_SHAREABLE: - sw_shareable |=3D ctrl_val; - break; - case RDT_MODE_EXCLUSIVE: - exclusive |=3D ctrl_val; - break; - case RDT_MODE_PSEUDO_LOCKSETUP: - /* - * RDT_MODE_PSEUDO_LOCKSETUP is possible - * here but not included since the CBM - * associated with this CLOSID in this mode - * is not initialized and no task or cpu can be - * assigned this CLOSID. - */ - break; - case RDT_MODE_PSEUDO_LOCKED: - case RDT_NUM_MODES: - WARN(1, - "invalid mode for closid %d\n", i); - break; + scoped_guard (mutex, &rdtgroup_mutex) { + hw_shareable =3D r->cache.shareable_bits; + list_for_each_entry(dom, &r->ctrl_domains, hdr.list) { + if (sep) + seq_putc(seq, ';'); + sw_shareable =3D 0; + exclusive =3D 0; + seq_printf(seq, "%d=3D", dom->hdr.id); + for (i =3D 0; i < closids_supported(); i++) { + if (!closid_allocated(i)) + continue; + ctrl_val =3D resctrl_arch_get_config(r, dom, i, + s->conf_type); + mode =3D rdtgroup_mode_by_closid(i); + switch (mode) { + case RDT_MODE_SHAREABLE: + sw_shareable |=3D ctrl_val; + break; + case RDT_MODE_EXCLUSIVE: + exclusive |=3D ctrl_val; + break; + case RDT_MODE_PSEUDO_LOCKSETUP: + /* + * RDT_MODE_PSEUDO_LOCKSETUP is possible + * here but not included since the CBM + * associated with this CLOSID in this mode + * is not initialized and no task or cpu can be + * assigned this CLOSID. + */ + break; + case RDT_MODE_PSEUDO_LOCKED: + case RDT_NUM_MODES: + WARN(1, + "invalid mode for closid %d\n", i); + break; + } } + for (i =3D r->cache.cbm_len - 1; i >=3D 0; i--) { + pseudo_locked =3D dom->plr ? dom->plr->cbm : 0; + hwb =3D test_bit(i, &hw_shareable); + swb =3D test_bit(i, &sw_shareable); + excl =3D test_bit(i, &exclusive); + psl =3D test_bit(i, &pseudo_locked); + if (hwb && swb) + seq_putc(seq, 'X'); + else if (hwb && !swb) + seq_putc(seq, 'H'); + else if (!hwb && swb) + seq_putc(seq, 'S'); + else if (excl) + seq_putc(seq, 'E'); + else if (psl) + seq_putc(seq, 'P'); + else /* Unused bits remain */ + seq_putc(seq, '0'); + } + sep =3D true; } - for (i =3D r->cache.cbm_len - 1; i >=3D 0; i--) { - pseudo_locked =3D dom->plr ? dom->plr->cbm : 0; - hwb =3D test_bit(i, &hw_shareable); - swb =3D test_bit(i, &sw_shareable); - excl =3D test_bit(i, &exclusive); - psl =3D test_bit(i, &pseudo_locked); - if (hwb && swb) - seq_putc(seq, 'X'); - else if (hwb && !swb) - seq_putc(seq, 'H'); - else if (!hwb && swb) - seq_putc(seq, 'S'); - else if (excl) - seq_putc(seq, 'E'); - else if (psl) - seq_putc(seq, 'P'); - else /* Unused bits remain */ - seq_putc(seq, '0'); - } - sep =3D true; + seq_putc(seq, '\n'); } - seq_putc(seq, '\n'); - mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); return 0; } @@ -1625,24 +1619,24 @@ static int mbm_config_show(struct seq_file *s, stru= ct rdt_resource *r, u32 evtid bool sep =3D false; =20 cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); + scoped_guard (mutex, &rdtgroup_mutex) { =20 - list_for_each_entry(dom, &r->mon_domains, hdr.list) { - if (sep) - seq_puts(s, ";"); + list_for_each_entry(dom, &r->mon_domains, hdr.list) { + if (sep) + seq_puts(s, ";"); =20 - memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info)); - mon_info.r =3D r; - mon_info.d =3D dom; - mon_info.evtid =3D evtid; - mondata_config_read(&mon_info); + memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info)); + mon_info.r =3D r; + mon_info.d =3D dom; + mon_info.evtid =3D evtid; + mondata_config_read(&mon_info); =20 - seq_printf(s, "%d=3D0x%02x", dom->hdr.id, mon_info.mon_config); - sep =3D true; - } - seq_puts(s, "\n"); + seq_printf(s, "%d=3D0x%02x", dom->hdr.id, mon_info.mon_config); + sep =3D true; + } + seq_puts(s, "\n"); =20 - mutex_unlock(&rdtgroup_mutex); + } cpus_read_unlock(); =20 return 0; @@ -1763,15 +1757,15 @@ static ssize_t mbm_total_bytes_config_write(struct = kernfs_open_file *of, return -EINVAL; =20 cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); + scoped_guard (mutex, &rdtgroup_mutex) { =20 - rdt_last_cmd_clear(); + rdt_last_cmd_clear(); =20 - buf[nbytes - 1] =3D '\0'; + buf[nbytes - 1] =3D '\0'; =20 - ret =3D mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID); + ret =3D mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID); =20 - mutex_unlock(&rdtgroup_mutex); + } cpus_read_unlock(); =20 return ret ?: nbytes; @@ -1789,15 +1783,15 @@ static ssize_t mbm_local_bytes_config_write(struct = kernfs_open_file *of, return -EINVAL; =20 cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); + scoped_guard (mutex, &rdtgroup_mutex) { =20 - rdt_last_cmd_clear(); + rdt_last_cmd_clear(); =20 - buf[nbytes - 1] =3D '\0'; + buf[nbytes - 1] =3D '\0'; =20 - ret =3D mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID); + ret =3D mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID); =20 - mutex_unlock(&rdtgroup_mutex); + } cpus_read_unlock(); =20 return ret ?: nbytes; @@ -2786,7 +2780,7 @@ static void rdt_move_group_tasks(struct rdtgroup *fro= m, struct rdtgroup *to, { struct task_struct *p, *t; =20 - read_lock(&tasklist_lock); + guard(read_lock)(&tasklist_lock); for_each_process_thread(p, t) { if (!from || is_closid_match(t, from) || is_rmid_match(t, from)) { @@ -2812,7 +2806,6 @@ static void rdt_move_group_tasks(struct rdtgroup *fro= m, struct rdtgroup *to, cpumask_set_cpu(task_cpu(t), mask); } } - read_unlock(&tasklist_lock); } =20 static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp) @@ -2959,22 +2952,22 @@ static void rdt_kill_sb(struct super_block *sb) struct rdt_resource *r; =20 cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); + scoped_guard (mutex, &rdtgroup_mutex) { =20 - rdt_disable_ctx(); + rdt_disable_ctx(); =20 - /* Put everything back to default values. */ - for_each_alloc_capable_rdt_resource(r) - resctrl_arch_reset_all_ctrls(r); + /* Put everything back to default values. */ + for_each_alloc_capable_rdt_resource(r) + resctrl_arch_reset_all_ctrls(r); =20 - resctrl_fs_teardown(); - if (resctrl_arch_alloc_capable()) - resctrl_arch_disable_alloc(); - if (resctrl_arch_mon_capable()) - resctrl_arch_disable_mon(); - resctrl_mounted =3D false; - kernfs_kill_sb(sb); - mutex_unlock(&rdtgroup_mutex); + resctrl_fs_teardown(); + if (resctrl_arch_alloc_capable()) + resctrl_arch_disable_alloc(); + if (resctrl_arch_mon_capable()) + resctrl_arch_disable_mon(); + resctrl_mounted =3D false; + kernfs_kill_sb(sb); + } cpus_read_unlock(); } =20 @@ -4008,7 +4001,7 @@ static void rdtgroup_destroy_root(void) =20 static void rdtgroup_setup_default(void) { - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); =20 rdtgroup_default.closid =3D RESCTRL_RESERVED_CLOSID; rdtgroup_default.mon.rmid =3D RESCTRL_RESERVED_RMID; @@ -4016,8 +4009,6 @@ static void rdtgroup_setup_default(void) INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list); =20 list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); - - mutex_unlock(&rdtgroup_mutex); } =20 static void domain_destroy_mon_state(struct rdt_mon_domain *d) @@ -4029,17 +4020,15 @@ static void domain_destroy_mon_state(struct rdt_mon= _domain *d) =20 void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_d= omain *d) { - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); =20 if (supports_mba_mbps() && r->rid =3D=3D RDT_RESOURCE_MBA) mba_sc_domain_destroy(r, d); - - mutex_unlock(&rdtgroup_mutex); } =20 void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_dom= ain *d) { - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); =20 /* * If resctrl is mounted, remove all the @@ -4064,8 +4053,6 @@ void resctrl_offline_mon_domain(struct rdt_resource *= r, struct rdt_mon_domain *d } =20 domain_destroy_mon_state(d); - - mutex_unlock(&rdtgroup_mutex); } =20 /** @@ -4116,15 +4103,13 @@ int resctrl_online_ctrl_domain(struct rdt_resource = *r, struct rdt_ctrl_domain *d { int err =3D 0; =20 - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); =20 if (supports_mba_mbps() && r->rid =3D=3D RDT_RESOURCE_MBA) { /* RDT_RESOURCE_MBA is never mon_capable */ err =3D mba_sc_domain_allocate(r, d); } =20 - mutex_unlock(&rdtgroup_mutex); - return err; } =20 @@ -4132,11 +4117,11 @@ int resctrl_online_mon_domain(struct rdt_resource *= r, struct rdt_mon_domain *d) { int err; =20 - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); =20 err =3D domain_setup_mon_state(r, d); if (err) - goto out_unlock; + return err; =20 if (resctrl_is_mbm_enabled()) { INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); @@ -4156,18 +4141,14 @@ int resctrl_online_mon_domain(struct rdt_resource *= r, struct rdt_mon_domain *d) if (resctrl_mounted && resctrl_arch_mon_capable()) mkdir_mondata_subdir_allrdtgrp(r, d); =20 -out_unlock: - mutex_unlock(&rdtgroup_mutex); - return err; } =20 void resctrl_online_cpu(unsigned int cpu) { - mutex_lock(&rdtgroup_mutex); - /* The CPU is set in default rdtgroup after online. */ - cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); - mutex_unlock(&rdtgroup_mutex); + scoped_guard (mutex, &rdtgroup_mutex) + /* The CPU is set in default rdtgroup after online. */ + cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); } =20 static void clear_childcpus(struct rdtgroup *r, unsigned int cpu) @@ -4202,7 +4183,7 @@ void resctrl_offline_cpu(unsigned int cpu) struct rdt_mon_domain *d; struct rdtgroup *rdtgrp; =20 - mutex_lock(&rdtgroup_mutex); + guard(mutex)(&rdtgroup_mutex); list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) { clear_childcpus(rdtgrp, cpu); @@ -4211,7 +4192,7 @@ void resctrl_offline_cpu(unsigned int cpu) } =20 if (!l3->mon_capable) - goto out_unlock; + return; =20 d =3D get_mon_domain_from_cpu(cpu, l3); if (d) { @@ -4225,9 +4206,6 @@ void resctrl_offline_cpu(unsigned int cpu) cqm_setup_limbo_handler(d, 0, cpu); } } - -out_unlock: - mutex_unlock(&rdtgroup_mutex); } =20 /* @@ -4338,9 +4316,8 @@ void resctrl_exit(void) cpus_read_lock(); WARN_ON_ONCE(resctrl_online_domains_exist()); =20 - mutex_lock(&rdtgroup_mutex); - resctrl_fs_teardown(); - mutex_unlock(&rdtgroup_mutex); + scoped_guard (mutex, &rdtgroup_mutex) + resctrl_fs_teardown(); =20 cpus_read_unlock(); =20 --=20 2.43.0