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synced 2024-11-24 12:44:11 +08:00
get rid of s_files and files_lock
The only thing we need it for is alt-sysrq-r (emergency remount r/o) and these days we can do just as well without going through the list of files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
8b61e74ffc
commit
eee5cc2702
125
fs/file_table.c
125
fs/file_table.c
@ -36,8 +36,6 @@ struct files_stat_struct files_stat = {
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.max_files = NR_FILE
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};
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DEFINE_STATIC_LGLOCK(files_lglock);
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/* SLAB cache for file structures */
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static struct kmem_cache *filp_cachep __read_mostly;
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@ -134,7 +132,6 @@ struct file *get_empty_filp(void)
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return ERR_PTR(error);
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}
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INIT_LIST_HEAD(&f->f_u.fu_list);
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atomic_long_set(&f->f_count, 1);
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rwlock_init(&f->f_owner.lock);
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spin_lock_init(&f->f_lock);
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@ -304,7 +301,6 @@ void fput(struct file *file)
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if (atomic_long_dec_and_test(&file->f_count)) {
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struct task_struct *task = current;
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file_sb_list_del(file);
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if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) {
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init_task_work(&file->f_u.fu_rcuhead, ____fput);
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if (!task_work_add(task, &file->f_u.fu_rcuhead, true))
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@ -333,7 +329,6 @@ void __fput_sync(struct file *file)
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{
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if (atomic_long_dec_and_test(&file->f_count)) {
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struct task_struct *task = current;
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file_sb_list_del(file);
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BUG_ON(!(task->flags & PF_KTHREAD));
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__fput(file);
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}
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@ -345,129 +340,10 @@ void put_filp(struct file *file)
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{
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if (atomic_long_dec_and_test(&file->f_count)) {
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security_file_free(file);
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file_sb_list_del(file);
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file_free(file);
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}
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}
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static inline int file_list_cpu(struct file *file)
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{
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#ifdef CONFIG_SMP
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return file->f_sb_list_cpu;
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#else
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return smp_processor_id();
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#endif
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}
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/* helper for file_sb_list_add to reduce ifdefs */
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static inline void __file_sb_list_add(struct file *file, struct super_block *sb)
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{
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struct list_head *list;
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#ifdef CONFIG_SMP
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int cpu;
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cpu = smp_processor_id();
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file->f_sb_list_cpu = cpu;
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list = per_cpu_ptr(sb->s_files, cpu);
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#else
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list = &sb->s_files;
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#endif
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list_add(&file->f_u.fu_list, list);
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}
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/**
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* file_sb_list_add - add a file to the sb's file list
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* @file: file to add
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* @sb: sb to add it to
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*
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* Use this function to associate a file with the superblock of the inode it
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* refers to.
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*/
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void file_sb_list_add(struct file *file, struct super_block *sb)
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{
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if (likely(!(file->f_mode & FMODE_WRITE)))
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return;
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if (!S_ISREG(file_inode(file)->i_mode))
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return;
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lg_local_lock(&files_lglock);
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__file_sb_list_add(file, sb);
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lg_local_unlock(&files_lglock);
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}
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/**
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* file_sb_list_del - remove a file from the sb's file list
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* @file: file to remove
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* @sb: sb to remove it from
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*
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* Use this function to remove a file from its superblock.
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*/
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void file_sb_list_del(struct file *file)
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{
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if (!list_empty(&file->f_u.fu_list)) {
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lg_local_lock_cpu(&files_lglock, file_list_cpu(file));
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list_del_init(&file->f_u.fu_list);
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lg_local_unlock_cpu(&files_lglock, file_list_cpu(file));
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}
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}
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#ifdef CONFIG_SMP
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/*
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* These macros iterate all files on all CPUs for a given superblock.
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* files_lglock must be held globally.
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*/
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#define do_file_list_for_each_entry(__sb, __file) \
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{ \
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int i; \
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for_each_possible_cpu(i) { \
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struct list_head *list; \
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list = per_cpu_ptr((__sb)->s_files, i); \
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list_for_each_entry((__file), list, f_u.fu_list)
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#define while_file_list_for_each_entry \
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} \
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}
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#else
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#define do_file_list_for_each_entry(__sb, __file) \
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{ \
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struct list_head *list; \
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list = &(sb)->s_files; \
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list_for_each_entry((__file), list, f_u.fu_list)
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#define while_file_list_for_each_entry \
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}
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#endif
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/**
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* mark_files_ro - mark all files read-only
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* @sb: superblock in question
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*
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* All files are marked read-only. We don't care about pending
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* delete files so this should be used in 'force' mode only.
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*/
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void mark_files_ro(struct super_block *sb)
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{
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struct file *f;
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lg_global_lock(&files_lglock);
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do_file_list_for_each_entry(sb, f) {
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if (!file_count(f))
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continue;
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if (!(f->f_mode & FMODE_WRITE))
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continue;
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spin_lock(&f->f_lock);
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f->f_mode &= ~FMODE_WRITE;
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spin_unlock(&f->f_lock);
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if (file_check_writeable(f) != 0)
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continue;
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__mnt_drop_write(f->f_path.mnt);
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file_release_write(f);
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} while_file_list_for_each_entry;
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lg_global_unlock(&files_lglock);
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}
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void __init files_init(unsigned long mempages)
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{
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unsigned long n;
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@ -483,6 +359,5 @@ void __init files_init(unsigned long mempages)
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n = (mempages * (PAGE_SIZE / 1024)) / 10;
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files_stat.max_files = max_t(unsigned long, n, NR_FILE);
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files_defer_init();
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lg_lock_init(&files_lglock, "files_lglock");
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percpu_counter_init(&nr_files, 0);
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}
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@ -73,9 +73,6 @@ extern void chroot_fs_refs(const struct path *, const struct path *);
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/*
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* file_table.c
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*/
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extern void file_sb_list_add(struct file *f, struct super_block *sb);
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extern void file_sb_list_del(struct file *f);
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extern void mark_files_ro(struct super_block *);
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extern struct file *get_empty_filp(void);
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/*
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@ -685,7 +685,6 @@ static int do_dentry_open(struct file *f,
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}
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f->f_mapping = inode->i_mapping;
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file_sb_list_add(f, inode->i_sb);
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if (unlikely(f->f_mode & FMODE_PATH)) {
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f->f_op = &empty_fops;
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@ -724,7 +723,6 @@ static int do_dentry_open(struct file *f,
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cleanup_all:
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fops_put(f->f_op);
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file_sb_list_del(f);
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if (f->f_mode & FMODE_WRITE) {
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put_write_access(inode);
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if (!special_file(inode->i_mode)) {
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15
fs/super.c
15
fs/super.c
@ -140,9 +140,6 @@ static void destroy_super(struct super_block *s)
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int i;
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list_lru_destroy(&s->s_dentry_lru);
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list_lru_destroy(&s->s_inode_lru);
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#ifdef CONFIG_SMP
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free_percpu(s->s_files);
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#endif
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for (i = 0; i < SB_FREEZE_LEVELS; i++)
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percpu_counter_destroy(&s->s_writers.counter[i]);
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security_sb_free(s);
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@ -172,15 +169,6 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
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if (security_sb_alloc(s))
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goto fail;
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#ifdef CONFIG_SMP
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s->s_files = alloc_percpu(struct list_head);
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if (!s->s_files)
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goto fail;
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for_each_possible_cpu(i)
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INIT_LIST_HEAD(per_cpu_ptr(s->s_files, i));
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#else
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INIT_LIST_HEAD(&s->s_files);
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#endif
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for (i = 0; i < SB_FREEZE_LEVELS; i++) {
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if (percpu_counter_init(&s->s_writers.counter[i], 0) < 0)
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goto fail;
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@ -722,7 +710,8 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
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make sure there are no rw files opened */
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if (remount_ro) {
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if (force) {
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mark_files_ro(sb);
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sb->s_readonly_remount = 1;
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smp_wmb();
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} else {
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retval = sb_prepare_remount_readonly(sb);
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if (retval)
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@ -764,12 +764,7 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
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#define FILE_MNT_WRITE_RELEASED 2
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struct file {
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/*
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* fu_list becomes invalid after file_free is called and queued via
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* fu_rcuhead for RCU freeing
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*/
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union {
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struct list_head fu_list;
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struct llist_node fu_llist;
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struct rcu_head fu_rcuhead;
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} f_u;
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@ -783,9 +778,6 @@ struct file {
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* Must not be taken from IRQ context.
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*/
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spinlock_t f_lock;
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#ifdef CONFIG_SMP
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int f_sb_list_cpu;
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#endif
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atomic_long_t f_count;
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unsigned int f_flags;
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fmode_t f_mode;
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@ -1264,11 +1256,6 @@ struct super_block {
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struct list_head s_inodes; /* all inodes */
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struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */
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#ifdef CONFIG_SMP
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struct list_head __percpu *s_files;
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#else
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struct list_head s_files;
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#endif
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struct list_head s_mounts; /* list of mounts; _not_ for fs use */
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struct block_device *s_bdev;
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struct backing_dev_info *s_bdi;
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