From f2a745c41df44c32149abb27b80e92cede772551 Mon Sep 17 00:00:00 2001 From: Richard Yao Date: Wed, 3 Jul 2013 16:34:52 -0400 Subject: Linux 3.10 compat: Do not rely on struct proc_dir_entry definition Linux kernel commit torvalds/linux#59d8053f moved the definition of struct proc_dir_entry from include/linux/proc_fs.h to the private header fs/proc/internal.h. The SPL relied on that to map Solaris' kstat to entries in /proc/spl/kstat. Since the proc_dir_entry structure is now private the only safe thing to do is wrap the opaque proc handle with our own structure. This actually ends up simplify the code and is good because it moves us away from depending on implementation details of /proc. Signed-off-by: Richard Yao Signed-off-by: Brian Behlendorf Issue #257 --- include/linux/proc_compat.h | 3 - include/sys/kstat.h | 8 +++ module/spl/spl-kstat.c | 135 ++++++++++++++++++++++++++++---------------- module/spl/spl-proc.c | 37 +----------- 4 files changed, 95 insertions(+), 88 deletions(-) diff --git a/include/linux/proc_compat.h b/include/linux/proc_compat.h index 434ffa3f1..7b044e7e1 100644 --- a/include/linux/proc_compat.h +++ b/include/linux/proc_compat.h @@ -43,9 +43,6 @@ #endif extern struct proc_dir_entry *proc_spl_kstat; -struct proc_dir_entry *proc_dir_entry_find(struct proc_dir_entry *root, - const char *str); -int proc_dir_entries(struct proc_dir_entry *root); int spl_proc_init(void); void spl_proc_fini(void); diff --git a/include/sys/kstat.h b/include/sys/kstat.h index 9275c1ea4..da3c5899d 100644 --- a/include/sys/kstat.h +++ b/include/sys/kstat.h @@ -83,6 +83,13 @@ struct kstat_s; typedef int kid_t; /* unique kstat id */ typedef int kstat_update_t(struct kstat_s *, int); /* dynamic update cb */ +typedef struct kstat_module { + char ksm_name[KSTAT_STRLEN+1]; /* module name */ + struct list_head ksm_module_list; /* module linkage */ + struct list_head ksm_kstat_list; /* list of kstat entries */ + struct proc_dir_entry *ksm_proc; /* proc entry */ +} kstat_module_t; + typedef struct kstat_s { int ks_magic; /* magic value */ kid_t ks_kid; /* unique kstat ID */ @@ -102,6 +109,7 @@ typedef struct kstat_s { void *ks_private; /* private data */ kmutex_t ks_lock; /* kstat data lock */ struct list_head ks_list; /* kstat linkage */ + kstat_module_t *ks_owner; /* kstat module linkage */ } kstat_t; typedef struct kstat_named_s { diff --git a/module/spl/spl-kstat.c b/module/spl/spl-kstat.c index 2e5590101..4e900c066 100644 --- a/module/spl/spl-kstat.c +++ b/module/spl/spl-kstat.c @@ -37,8 +37,8 @@ #define PDE_DATA(x) (PDE(x)->data) #endif -static spinlock_t kstat_lock; -static struct list_head kstat_list; +static kmutex_t kstat_module_lock; +static struct list_head kstat_module_list; static kid_t kstat_id; static void @@ -351,6 +351,47 @@ static struct seq_operations kstat_seq_ops = { .stop = kstat_seq_stop, }; +static kstat_module_t * +kstat_find_module(char *name) +{ + kstat_module_t *module; + + list_for_each_entry(module, &kstat_module_list, ksm_module_list) + if (strncmp(name, module->ksm_name, KSTAT_STRLEN) == 0) + return (module); + + return (NULL); +} + +static kstat_module_t * +kstat_create_module(char *name) +{ + kstat_module_t *module; + struct proc_dir_entry *pde; + + pde = proc_mkdir(name, proc_spl_kstat); + if (pde == NULL) + return (NULL); + + module = kmem_alloc(sizeof (kstat_module_t), KM_SLEEP); + module->ksm_proc = pde; + strlcpy(module->ksm_name, name, KSTAT_STRLEN+1); + INIT_LIST_HEAD(&module->ksm_kstat_list); + list_add_tail(&module->ksm_module_list, &kstat_module_list); + + return (module); + +} + +static void +kstat_delete_module(kstat_module_t *module) +{ + ASSERT(list_empty(&module->ksm_kstat_list)); + remove_proc_entry(module->ksm_name, proc_spl_kstat); + list_del(&module->ksm_module_list); + kmem_free(module, sizeof(kstat_module_t)); +} + static int proc_kstat_open(struct inode *inode, struct file *filp) { @@ -393,10 +434,10 @@ __kstat_create(const char *ks_module, int ks_instance, const char *ks_name, if (ksp == NULL) return ksp; - spin_lock(&kstat_lock); + mutex_enter(&kstat_module_lock); ksp->ks_kid = kstat_id; kstat_id++; - spin_unlock(&kstat_lock); + mutex_exit(&kstat_module_lock); ksp->ks_magic = KS_MAGIC; mutex_init(&ksp->ks_lock, NULL, MUTEX_DEFAULT, NULL); @@ -459,71 +500,64 @@ EXPORT_SYMBOL(__kstat_create); void __kstat_install(kstat_t *ksp) { - struct proc_dir_entry *de_module, *de_name; + kstat_module_t *module; kstat_t *tmp; - int rc = 0; - SENTRY; - - spin_lock(&kstat_lock); - /* Item may only be added to the list once */ - list_for_each_entry(tmp, &kstat_list, ks_list) { - if (tmp == ksp) { - spin_unlock(&kstat_lock); - SGOTO(out, rc = -EEXIST); - } - } + ASSERT(ksp); - list_add_tail(&ksp->ks_list, &kstat_list); - spin_unlock(&kstat_lock); + mutex_enter(&kstat_module_lock); - de_module = proc_dir_entry_find(proc_spl_kstat, ksp->ks_module); - if (de_module == NULL) { - de_module = proc_mkdir(ksp->ks_module, proc_spl_kstat); - if (de_module == NULL) - SGOTO(out, rc = -EUNATCH); + module = kstat_find_module(ksp->ks_module); + if (module == NULL) { + module = kstat_create_module(ksp->ks_module); + if (module == NULL) + goto out; } - de_name = create_proc_entry(ksp->ks_name, 0444, de_module); - if (de_name == NULL) - SGOTO(out, rc = -EUNATCH); + /* + * 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) + goto out; + + list_add_tail(&ksp->ks_list, &module->ksm_kstat_list); mutex_enter(&ksp->ks_lock); - ksp->ks_proc = de_name; - de_name->proc_fops = &proc_kstat_operations; - de_name->data = (void *)ksp; + ksp->ks_owner = module; + ksp->ks_proc = proc_create_data(ksp->ks_name, 0444, + module->ksm_proc, &proc_kstat_operations, (void *)ksp); + if (ksp->ks_proc == NULL) { + list_del_init(&ksp->ks_list); + if (list_empty(&module->ksm_kstat_list)) + kstat_delete_module(module); + } mutex_exit(&ksp->ks_lock); out: - if (rc) { - spin_lock(&kstat_lock); - list_del_init(&ksp->ks_list); - spin_unlock(&kstat_lock); - } - - SEXIT; + mutex_exit(&kstat_module_lock); } EXPORT_SYMBOL(__kstat_install); void __kstat_delete(kstat_t *ksp) { - struct proc_dir_entry *de_module; + kstat_module_t *module = ksp->ks_owner; - spin_lock(&kstat_lock); - list_del_init(&ksp->ks_list); - spin_unlock(&kstat_lock); + mutex_enter(&kstat_module_lock); + list_del_init(&ksp->ks_list); + mutex_exit(&kstat_module_lock); - if (ksp->ks_proc) { - de_module = ksp->ks_proc->parent; - remove_proc_entry(ksp->ks_name, de_module); + if (ksp->ks_proc) { + remove_proc_entry(ksp->ks_name, module->ksm_proc); - /* Remove top level module directory if it's empty */ - if (proc_dir_entries(de_module) == 0) - remove_proc_entry(de_module->name, de_module->parent); + /* Remove top level module directory if it's empty */ + if (list_empty(&module->ksm_kstat_list)) + kstat_delete_module(module); } if (!(ksp->ks_flags & KSTAT_FLAG_VIRTUAL)) - kmem_free(ksp->ks_data, ksp->ks_data_size); + kmem_free(ksp->ks_data, ksp->ks_data_size); mutex_destroy(&ksp->ks_lock); kmem_free(ksp, sizeof(*ksp)); @@ -536,8 +570,8 @@ int spl_kstat_init(void) { SENTRY; - spin_lock_init(&kstat_lock); - INIT_LIST_HEAD(&kstat_list); + mutex_init(&kstat_module_lock, NULL, MUTEX_DEFAULT, NULL); + INIT_LIST_HEAD(&kstat_module_list); kstat_id = 0; SRETURN(0); } @@ -546,7 +580,8 @@ void spl_kstat_fini(void) { SENTRY; - ASSERT(list_empty(&kstat_list)); + ASSERT(list_empty(&kstat_module_list)); + mutex_destroy(&kstat_module_lock); SEXIT; } diff --git a/module/spl/spl-proc.c b/module/spl/spl-proc.c index cd4fa1b47..b8379d0fe 100644 --- a/module/spl/spl-proc.c +++ b/module/spl/spl-proc.c @@ -1120,39 +1120,6 @@ static struct ctl_table spl_root[] = { { 0 } }; -static int -proc_dir_entry_match(int len, const char *name, struct proc_dir_entry *de) -{ - if (de->namelen != len) - return 0; - - return !memcmp(name, de->name, len); -} - -struct proc_dir_entry * -proc_dir_entry_find(struct proc_dir_entry *root, const char *str) -{ - struct proc_dir_entry *de; - - for (de = root->subdir; de; de = de->next) - if (proc_dir_entry_match(strlen(str), str, de)) - return de; - - return NULL; -} - -int -proc_dir_entries(struct proc_dir_entry *root) -{ - struct proc_dir_entry *de; - int i = 0; - - for (de = root->subdir; de; de = de->next) - i++; - - return i; -} - int spl_proc_init(void) { @@ -1174,11 +1141,11 @@ spl_proc_init(void) if (proc_spl_kmem == NULL) SGOTO(out, rc = -EUNATCH); - proc_spl_kmem_slab = create_proc_entry("slab", 0444, proc_spl_kmem); + proc_spl_kmem_slab = proc_create_data("slab", 0444, + proc_spl_kmem, &proc_slab_operations, NULL); if (proc_spl_kmem_slab == NULL) SGOTO(out, rc = -EUNATCH); - proc_spl_kmem_slab->proc_fops = &proc_slab_operations; #endif /* DEBUG_KMEM */ proc_spl_kstat = proc_mkdir("kstat", proc_spl); -- cgit v1.2.3