Fixes for procfs files backed by linked lists

[mirror_zfs.git] / module / spl / spl-kstat.c

diff --git a/module/spl/spl-kstat.c b/module/spl/spl-kstat.c
index c3fc2e4b24f0e36d2628aed2439f99063e16ae08..8683693c8e6735cc047d76a3e1857ff185b60a19 100644 (file)
--- a/module/spl/spl-kstat.c
+++ b/module/spl/spl-kstat.c
@@ -530,6 +530,18 @@ __kstat_set_raw_ops(kstat_t *ksp,
 }
 EXPORT_SYMBOL(__kstat_set_raw_ops);
 
+void
+kstat_proc_entry_init(kstat_proc_entry_t *kpep, const char *module,
+    const char *name)
+{
+       kpep->kpe_owner = NULL;
+       kpep->kpe_proc = NULL;
+       INIT_LIST_HEAD(&kpep->kpe_list);
+       strncpy(kpep->kpe_module, module, KSTAT_STRLEN);
+       strncpy(kpep->kpe_name, name, KSTAT_STRLEN);
+}
+EXPORT_SYMBOL(kstat_proc_entry_init);
+
 kstat_t *
 __kstat_create(const char *ks_module, int ks_instance, const char *ks_name,
     const char *ks_class, uchar_t ks_type, uint_t ks_ndata,
@@ -556,13 +568,10 @@ __kstat_create(const char *ks_module, int ks_instance, const char *ks_name,
        ksp->ks_magic = KS_MAGIC;
        mutex_init(&ksp->ks_private_lock, NULL, MUTEX_DEFAULT, NULL);
        ksp->ks_lock = &ksp->ks_private_lock;
-       INIT_LIST_HEAD(&ksp->ks_list);
 
        ksp->ks_crtime = gethrtime();
        ksp->ks_snaptime = ksp->ks_crtime;
-       strncpy(ksp->ks_module, ks_module, KSTAT_STRLEN);
        ksp->ks_instance = ks_instance;
-       strncpy(ksp->ks_name, ks_name, KSTAT_STRLEN);
        strncpy(ksp->ks_class, ks_class, KSTAT_STRLEN);
        ksp->ks_type = ks_type;
        ksp->ks_flags = ks_flags;
@@ -573,6 +582,7 @@ __kstat_create(const char *ks_module, int ks_instance, const char *ks_name,
        ksp->ks_raw_ops.addr = NULL;
        ksp->ks_raw_buf = NULL;
        ksp->ks_raw_bufsize = 0;
+       kstat_proc_entry_init(&ksp->ks_proc, ks_module, ks_name);
 
        switch (ksp->ks_type) {
                case KSTAT_TYPE_RAW:
@@ -614,14 +624,14 @@ __kstat_create(const char *ks_module, int ks_instance, const char *ks_name,
 EXPORT_SYMBOL(__kstat_create);
 
 static int
-kstat_detect_collision(kstat_t *ksp)
+kstat_detect_collision(kstat_proc_entry_t *kpep)
 {
        kstat_module_t *module;
-       kstat_t *tmp;
+       kstat_proc_entry_t *tmp;
        char *parent;
        char *cp;
 
-       parent = kmem_asprintf("%s", ksp->ks_module);
+       parent = kmem_asprintf("%s", kpep->kpe_module);
 
        if ((cp = strrchr(parent, '/')) == NULL) {
                strfree(parent);
@@ -630,8 +640,8 @@ kstat_detect_collision(kstat_t *ksp)
 
        cp[0] = '\0';
        if ((module = kstat_find_module(parent)) != NULL) {
-               list_for_each_entry(tmp, &module->ksm_kstat_list, ks_list) {
-                       if (strncmp(tmp->ks_name, cp+1, KSTAT_STRLEN) == 0) {
+               list_for_each_entry(tmp, &module->ksm_kstat_list, kpe_list) {
+                       if (strncmp(tmp->kpe_name, cp+1, KSTAT_STRLEN) == 0) {
                                strfree(parent);
                                return (EEXIST);
                        }
@@ -642,24 +652,30 @@ kstat_detect_collision(kstat_t *ksp)
        return (0);
 }
 
+/*
+ * Add a file to the proc filesystem under the kstat namespace (i.e.
+ * /proc/spl/kstat/). The file need not necessarily be implemented as a
+ * kstat.
+ */
 void
-__kstat_install(kstat_t *ksp)
+kstat_proc_entry_install(kstat_proc_entry_t *kpep,
+    const struct file_operations *file_ops, void *data)
 {
        kstat_module_t *module;
-       kstat_t *tmp;
+       kstat_proc_entry_t *tmp;
 
-       ASSERT(ksp);
+       ASSERT(kpep);
 
        mutex_enter(&kstat_module_lock);
 
-       module = kstat_find_module(ksp->ks_module);
+       module = kstat_find_module(kpep->kpe_module);
        if (module == NULL) {
-               if (kstat_detect_collision(ksp) != 0) {
+               if (kstat_detect_collision(kpep) != 0) {
                        cmn_err(CE_WARN, "kstat_create('%s', '%s'): namespace" \
-                           " collision", ksp->ks_module, ksp->ks_name);
+                           " collision", kpep->kpe_module, kpep->kpe_name);
                        goto out;
                }
-               module = kstat_create_module(ksp->ks_module);
+               module = kstat_create_module(kpep->kpe_module);
                if (module == NULL)
                        goto out;
        }
@@ -668,44 +684,60 @@ __kstat_install(kstat_t *ksp)
         * Only one entry by this name per-module, on failure the module
         * shouldn't be deleted because we know it has at least one entry.
         */
-       list_for_each_entry(tmp, &module->ksm_kstat_list, ks_list) {
-               if (strncmp(tmp->ks_name, ksp->ks_name, KSTAT_STRLEN) == 0)
+       list_for_each_entry(tmp, &module->ksm_kstat_list, kpe_list) {
+               if (strncmp(tmp->kpe_name, kpep->kpe_name, KSTAT_STRLEN) == 0)
                        goto out;
        }
 
-       list_add_tail(&ksp->ks_list, &module->ksm_kstat_list);
+       list_add_tail(&kpep->kpe_list, &module->ksm_kstat_list);
 
-       mutex_enter(ksp->ks_lock);
-       ksp->ks_owner = module;
-       ksp->ks_proc = proc_create_data(ksp->ks_name, 0644,
-           module->ksm_proc, &proc_kstat_operations, (void *)ksp);
-       if (ksp->ks_proc == NULL) {
-               list_del_init(&ksp->ks_list);
+       kpep->kpe_owner = module;
+       kpep->kpe_proc = proc_create_data(kpep->kpe_name, 0644,
+           module->ksm_proc, file_ops, data);
+       if (kpep->kpe_proc == NULL) {
+               list_del_init(&kpep->kpe_list);
                if (list_empty(&module->ksm_kstat_list))
                        kstat_delete_module(module);
        }
-       mutex_exit(ksp->ks_lock);
 out:
        mutex_exit(&kstat_module_lock);
+
+}
+EXPORT_SYMBOL(kstat_proc_entry_install);
+
+void
+__kstat_install(kstat_t *ksp)
+{
+       ASSERT(ksp);
+       kstat_proc_entry_install(&ksp->ks_proc, &proc_kstat_operations, ksp);
 }
 EXPORT_SYMBOL(__kstat_install);
 
 void
-__kstat_delete(kstat_t *ksp)
+kstat_proc_entry_delete(kstat_proc_entry_t *kpep)
 {
-       kstat_module_t *module = ksp->ks_owner;
+       kstat_module_t *module = kpep->kpe_owner;
+       if (kpep->kpe_proc)
+               remove_proc_entry(kpep->kpe_name, module->ksm_proc);
 
        mutex_enter(&kstat_module_lock);
-       list_del_init(&ksp->ks_list);
+       list_del_init(&kpep->kpe_list);
+
+       /*
+        * Remove top level module directory if it wasn't empty before, but now
+        * is.
+        */
+       if (kpep->kpe_proc && list_empty(&module->ksm_kstat_list))
+               kstat_delete_module(module);
        mutex_exit(&kstat_module_lock);
 
-       if (ksp->ks_proc) {
-               remove_proc_entry(ksp->ks_name, module->ksm_proc);
+}
+EXPORT_SYMBOL(kstat_proc_entry_delete);
 
-               /* Remove top level module directory if it's empty */
-               if (list_empty(&module->ksm_kstat_list))
-                       kstat_delete_module(module);
-       }
+void
+__kstat_delete(kstat_t *ksp)
+{
+       kstat_proc_entry_delete(&ksp->ks_proc);
 
        if (!(ksp->ks_flags & KSTAT_FLAG_VIRTUAL))
                kmem_free(ksp->ks_data, ksp->ks_data_size);