X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Ffile_table.c;h=ad17e05ebf95f07888b15f2b09a7b37ac89b9710;hb=a68a6ab313ea321f84978cbe42cca025651e1dc2;hp=485dc0eddd6707839120324ab552d94ef5ed5ab9;hpb=91e14b294f3fe4d8b28516b21ceef187ea9b1bdf;p=firefly-linux-kernel-4.4.55.git diff --git a/fs/file_table.c b/fs/file_table.c index 485dc0eddd67..ad17e05ebf95 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -20,12 +20,12 @@ #include #include #include -#include #include #include #include #include #include +#include #include @@ -36,8 +36,6 @@ struct files_stat_struct files_stat = { .max_files = NR_FILE }; -DEFINE_STATIC_LGLOCK(files_lglock); - /* SLAB cache for file structures */ static struct kmem_cache *filp_cachep __read_mostly; @@ -54,7 +52,6 @@ static void file_free_rcu(struct rcu_head *head) static inline void file_free(struct file *f) { percpu_counter_dec(&nr_files); - file_check_state(f); call_rcu(&f->f_u.fu_rcuhead, file_free_rcu); } @@ -79,14 +76,14 @@ EXPORT_SYMBOL_GPL(get_max_files); * Handle nr_files sysctl */ #if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS) -int proc_nr_files(ctl_table *table, int write, +int proc_nr_files(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { files_stat.nr_files = get_nr_files(); return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); } #else -int proc_nr_files(ctl_table *table, int write, +int proc_nr_files(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; @@ -134,10 +131,10 @@ struct file *get_empty_filp(void) return ERR_PTR(error); } - INIT_LIST_HEAD(&f->f_u.fu_list); atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); spin_lock_init(&f->f_lock); + mutex_init(&f->f_pos_lock); eventpoll_init_file(f); /* f->f_version: 0 */ return f; @@ -153,18 +150,10 @@ over: /** * alloc_file - allocate and initialize a 'struct file' - * @mnt: the vfsmount on which the file will reside - * @dentry: the dentry representing the new file + * + * @path: the (dentry, vfsmount) pair for the new file * @mode: the mode with which the new file will be opened * @fop: the 'struct file_operations' for the new file - * - * Use this instead of get_empty_filp() to get a new - * 'struct file'. Do so because of the same initialization - * pitfalls reasons listed for init_file(). This is a - * preferred interface to using init_file(). - * - * If all the callers of init_file() are eliminated, its - * code should be moved into this function. */ struct file *alloc_file(struct path *path, fmode_t mode, const struct file_operations *fop) @@ -178,56 +167,27 @@ struct file *alloc_file(struct path *path, fmode_t mode, file->f_path = *path; file->f_inode = path->dentry->d_inode; file->f_mapping = path->dentry->d_inode->i_mapping; + if ((mode & FMODE_READ) && + likely(fop->read || fop->read_iter)) + mode |= FMODE_CAN_READ; + if ((mode & FMODE_WRITE) && + likely(fop->write || fop->write_iter)) + mode |= FMODE_CAN_WRITE; file->f_mode = mode; file->f_op = fop; - - /* - * These mounts don't really matter in practice - * for r/o bind mounts. They aren't userspace- - * visible. We do this for consistency, and so - * that we can do debugging checks at __fput() - */ - if ((mode & FMODE_WRITE) && !special_file(path->dentry->d_inode->i_mode)) { - file_take_write(file); - WARN_ON(mnt_clone_write(path->mnt)); - } if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) i_readcount_inc(path->dentry->d_inode); return file; } EXPORT_SYMBOL(alloc_file); -/** - * drop_file_write_access - give up ability to write to a file - * @file: the file to which we will stop writing - * - * This is a central place which will give up the ability - * to write to @file, along with access to write through - * its vfsmount. - */ -static void drop_file_write_access(struct file *file) -{ - struct vfsmount *mnt = file->f_path.mnt; - struct dentry *dentry = file->f_path.dentry; - struct inode *inode = dentry->d_inode; - - put_write_access(inode); - - if (special_file(inode->i_mode)) - return; - if (file_check_writeable(file) != 0) - return; - __mnt_drop_write(mnt); - file_release_write(file); -} - /* the real guts of fput() - releasing the last reference to file */ static void __fput(struct file *file) { struct dentry *dentry = file->f_path.dentry; struct vfsmount *mnt = file->f_path.mnt; - struct inode *inode = dentry->d_inode; + struct inode *inode = file->f_inode; might_sleep(); @@ -237,14 +197,14 @@ static void __fput(struct file *file) * in the file cleanup chain. */ eventpoll_release(file); - locks_remove_flock(file); + locks_remove_file(file); if (unlikely(file->f_flags & FASYNC)) { - if (file->f_op && file->f_op->fasync) + if (file->f_op->fasync) file->f_op->fasync(-1, file, 0); } ima_file_free(file); - if (file->f_op && file->f_op->release) + if (file->f_op->release) file->f_op->release(inode, file); security_file_free(file); if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL && @@ -255,8 +215,10 @@ static void __fput(struct file *file) put_pid(file->f_owner.pid); if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) i_readcount_dec(inode); - if (file->f_mode & FMODE_WRITE) - drop_file_write_access(file); + if (file->f_mode & FMODE_WRITER) { + put_write_access(inode); + __mnt_drop_write(mnt); + } file->f_path.dentry = NULL; file->f_path.mnt = NULL; file->f_inode = NULL; @@ -265,18 +227,15 @@ static void __fput(struct file *file) mntput(mnt); } -static DEFINE_SPINLOCK(delayed_fput_lock); -static LIST_HEAD(delayed_fput_list); +static LLIST_HEAD(delayed_fput_list); static void delayed_fput(struct work_struct *unused) { - LIST_HEAD(head); - spin_lock_irq(&delayed_fput_lock); - list_splice_init(&delayed_fput_list, &head); - spin_unlock_irq(&delayed_fput_lock); - while (!list_empty(&head)) { - struct file *f = list_first_entry(&head, struct file, f_u.fu_list); - list_del_init(&f->f_u.fu_list); - __fput(f); + struct llist_node *node = llist_del_all(&delayed_fput_list); + struct llist_node *next; + + for (; node; node = next) { + next = llist_next(node); + __fput(llist_entry(node, struct file, f_u.fu_llist)); } } @@ -300,24 +259,26 @@ void flush_delayed_fput(void) delayed_fput(NULL); } -static DECLARE_WORK(delayed_fput_work, delayed_fput); +static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput); void fput(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { struct task_struct *task = current; - unsigned long flags; - file_sb_list_del(file); if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { init_task_work(&file->f_u.fu_rcuhead, ____fput); if (!task_work_add(task, &file->f_u.fu_rcuhead, true)) return; + /* + * After this task has run exit_task_work(), + * task_work_add() will fail. Fall through to delayed + * fput to avoid leaking *file. + */ } - spin_lock_irqsave(&delayed_fput_lock, flags); - list_add(&file->f_u.fu_list, &delayed_fput_list); - schedule_work(&delayed_fput_work); - spin_unlock_irqrestore(&delayed_fput_lock, flags); + + if (llist_add(&file->f_u.fu_llist, &delayed_fput_list)) + schedule_delayed_work(&delayed_fput_work, 1); } } @@ -333,7 +294,6 @@ void __fput_sync(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { struct task_struct *task = current; - file_sb_list_del(file); BUG_ON(!(task->flags & PF_KTHREAD)); __fput(file); } @@ -345,142 +305,28 @@ void put_filp(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { security_file_free(file); - file_sb_list_del(file); file_free(file); } } -static inline int file_list_cpu(struct file *file) -{ -#ifdef CONFIG_SMP - return file->f_sb_list_cpu; -#else - return smp_processor_id(); -#endif -} - -/* helper for file_sb_list_add to reduce ifdefs */ -static inline void __file_sb_list_add(struct file *file, struct super_block *sb) -{ - struct list_head *list; -#ifdef CONFIG_SMP - int cpu; - cpu = smp_processor_id(); - file->f_sb_list_cpu = cpu; - list = per_cpu_ptr(sb->s_files, cpu); -#else - list = &sb->s_files; -#endif - list_add(&file->f_u.fu_list, list); -} - -/** - * file_sb_list_add - add a file to the sb's file list - * @file: file to add - * @sb: sb to add it to - * - * Use this function to associate a file with the superblock of the inode it - * refers to. - */ -void file_sb_list_add(struct file *file, struct super_block *sb) -{ - lg_local_lock(&files_lglock); - __file_sb_list_add(file, sb); - lg_local_unlock(&files_lglock); -} - -/** - * file_sb_list_del - remove a file from the sb's file list - * @file: file to remove - * @sb: sb to remove it from - * - * Use this function to remove a file from its superblock. - */ -void file_sb_list_del(struct file *file) -{ - if (!list_empty(&file->f_u.fu_list)) { - lg_local_lock_cpu(&files_lglock, file_list_cpu(file)); - list_del_init(&file->f_u.fu_list); - lg_local_unlock_cpu(&files_lglock, file_list_cpu(file)); - } +void __init files_init(void) +{ + filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0, + SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); + percpu_counter_init(&nr_files, 0, GFP_KERNEL); } -#ifdef CONFIG_SMP - /* - * These macros iterate all files on all CPUs for a given superblock. - * files_lglock must be held globally. + * One file with associated inode and dcache is very roughly 1K. Per default + * do not use more than 10% of our memory for files. */ -#define do_file_list_for_each_entry(__sb, __file) \ -{ \ - int i; \ - for_each_possible_cpu(i) { \ - struct list_head *list; \ - list = per_cpu_ptr((__sb)->s_files, i); \ - list_for_each_entry((__file), list, f_u.fu_list) - -#define while_file_list_for_each_entry \ - } \ -} - -#else - -#define do_file_list_for_each_entry(__sb, __file) \ -{ \ - struct list_head *list; \ - list = &(sb)->s_files; \ - list_for_each_entry((__file), list, f_u.fu_list) - -#define while_file_list_for_each_entry \ -} - -#endif - -/** - * mark_files_ro - mark all files read-only - * @sb: superblock in question - * - * All files are marked read-only. We don't care about pending - * delete files so this should be used in 'force' mode only. - */ -void mark_files_ro(struct super_block *sb) +void __init files_maxfiles_init(void) { - struct file *f; - - lg_global_lock(&files_lglock); - do_file_list_for_each_entry(sb, f) { - if (!S_ISREG(file_inode(f)->i_mode)) - continue; - if (!file_count(f)) - continue; - if (!(f->f_mode & FMODE_WRITE)) - continue; - spin_lock(&f->f_lock); - f->f_mode &= ~FMODE_WRITE; - spin_unlock(&f->f_lock); - if (file_check_writeable(f) != 0) - continue; - __mnt_drop_write(f->f_path.mnt); - file_release_write(f); - } while_file_list_for_each_entry; - lg_global_unlock(&files_lglock); -} - -void __init files_init(unsigned long mempages) -{ unsigned long n; + unsigned long memreserve = (totalram_pages - nr_free_pages()) * 3/2; - filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0, - SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); - - /* - * One file with associated inode and dcache is very roughly 1K. - * Per default don't use more than 10% of our memory for files. - */ + memreserve = min(memreserve, totalram_pages - 1); + n = ((totalram_pages - memreserve) * (PAGE_SIZE / 1024)) / 10; - n = (mempages * (PAGE_SIZE / 1024)) / 10; files_stat.max_files = max_t(unsigned long, n, NR_FILE); - files_defer_init(); - lg_lock_init(&files_lglock, "files_lglock"); - percpu_counter_init(&nr_files, 0); }