diff options
Diffstat (limited to 'fs/file_table.c')
| -rw-r--r-- | fs/file_table.c | 85 |
1 files changed, 58 insertions, 27 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index 7ec0b3e5f05d..d6eccd04d703 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -51,6 +51,7 @@ static void file_free_rcu(struct rcu_head *head) static inline void file_free(struct file *f) { + security_file_free(f); percpu_counter_dec(&nr_files); call_rcu(&f->f_u.fu_rcuhead, file_free_rcu); } @@ -100,9 +101,8 @@ int proc_nr_files(struct ctl_table *table, int write, * done, you will imbalance int the mount's writer count * and a warning at __fput() time. */ -struct file *get_empty_filp(void) +struct file *alloc_empty_file(int flags, const struct cred *cred) { - const struct cred *cred = current_cred(); static long old_max; struct file *f; int error; @@ -123,11 +123,10 @@ struct file *get_empty_filp(void) if (unlikely(!f)) return ERR_PTR(-ENOMEM); - percpu_counter_inc(&nr_files); f->f_cred = get_cred(cred); error = security_file_alloc(f); if (unlikely(error)) { - file_free(f); + file_free_rcu(&f->f_u.fu_rcuhead); return ERR_PTR(error); } @@ -136,7 +135,10 @@ struct file *get_empty_filp(void) spin_lock_init(&f->f_lock); mutex_init(&f->f_pos_lock); eventpoll_init_file(f); + f->f_flags = flags; + f->f_mode = OPEN_FMODE(flags); /* f->f_version: 0 */ + percpu_counter_inc(&nr_files); return f; over: @@ -152,15 +154,15 @@ over: * alloc_file - allocate and initialize a 'struct file' * * @path: the (dentry, vfsmount) pair for the new file - * @mode: the mode with which the new file will be opened + * @flags: O_... flags with which the new file will be opened * @fop: the 'struct file_operations' for the new file */ -struct file *alloc_file(const struct path *path, fmode_t mode, +static struct file *alloc_file(const struct path *path, int flags, const struct file_operations *fop) { struct file *file; - file = get_empty_filp(); + file = alloc_empty_file(flags, current_cred()); if (IS_ERR(file)) return file; @@ -168,19 +170,56 @@ struct file *alloc_file(const struct path *path, fmode_t mode, file->f_inode = path->dentry->d_inode; file->f_mapping = path->dentry->d_inode->i_mapping; file->f_wb_err = filemap_sample_wb_err(file->f_mapping); - if ((mode & FMODE_READ) && + if ((file->f_mode & FMODE_READ) && likely(fop->read || fop->read_iter)) - mode |= FMODE_CAN_READ; - if ((mode & FMODE_WRITE) && + file->f_mode |= FMODE_CAN_READ; + if ((file->f_mode & FMODE_WRITE) && likely(fop->write || fop->write_iter)) - mode |= FMODE_CAN_WRITE; - file->f_mode = mode; + file->f_mode |= FMODE_CAN_WRITE; + file->f_mode |= FMODE_OPENED; file->f_op = fop; - if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) + if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) i_readcount_inc(path->dentry->d_inode); return file; } -EXPORT_SYMBOL(alloc_file); + +struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt, + const char *name, int flags, + const struct file_operations *fops) +{ + static const struct dentry_operations anon_ops = { + .d_dname = simple_dname + }; + struct qstr this = QSTR_INIT(name, strlen(name)); + struct path path; + struct file *file; + + path.dentry = d_alloc_pseudo(mnt->mnt_sb, &this); + if (!path.dentry) + return ERR_PTR(-ENOMEM); + if (!mnt->mnt_sb->s_d_op) + d_set_d_op(path.dentry, &anon_ops); + path.mnt = mntget(mnt); + d_instantiate(path.dentry, inode); + file = alloc_file(&path, flags, fops); + if (IS_ERR(file)) { + ihold(inode); + path_put(&path); + } + return file; +} +EXPORT_SYMBOL(alloc_file_pseudo); + +struct file *alloc_file_clone(struct file *base, int flags, + const struct file_operations *fops) +{ + struct file *f = alloc_file(&base->f_path, flags, fops); + if (!IS_ERR(f)) { + path_get(&f->f_path); + f->f_mapping = base->f_mapping; + } + return f; +} /* the real guts of fput() - releasing the last reference to file */ @@ -190,6 +229,9 @@ static void __fput(struct file *file) struct vfsmount *mnt = file->f_path.mnt; struct inode *inode = file->f_inode; + if (unlikely(!(file->f_mode & FMODE_OPENED))) + goto out; + might_sleep(); fsnotify_close(file); @@ -207,7 +249,6 @@ static void __fput(struct file *file) } 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 && !(file->f_mode & FMODE_PATH))) { cdev_put(inode->i_cdev); @@ -220,12 +261,10 @@ static void __fput(struct file *file) put_write_access(inode); __mnt_drop_write(mnt); } - file->f_path.dentry = NULL; - file->f_path.mnt = NULL; - file->f_inode = NULL; - file_free(file); dput(dentry); mntput(mnt); +out: + file_free(file); } static LLIST_HEAD(delayed_fput_list); @@ -300,14 +339,6 @@ void __fput_sync(struct file *file) EXPORT_SYMBOL(fput); -void put_filp(struct file *file) -{ - if (atomic_long_dec_and_test(&file->f_count)) { - security_file_free(file); - file_free(file); - } -} - void __init files_init(void) { filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0, |