Commit 2394b311 authored by Jens Axboe's avatar Jens Axboe
Browse files

Merge branch 'vfs.file' of... 

Merge branch 'vfs.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs into for-6.8/io_uring

Merge vfs.file from the VFS tree to avoid conflicts with receive_fd() now
having 3 arguments rather than just 2.

* 'vfs.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  file: remove __receive_fd()
  file: stop exposing receive_fd_user()
  fs: replace f_rcuhead with f_task_work
  file: remove pointless wrapper
  file: s/close_fd_get_file()/file_close_fd()/g
  Improve __fget_files_rcu() code generation (and thus __fget_light())
  file: massage cleanup of files that failed to open
parents a39b6ac3 4e94ddfe

drivers/android/binder.c

+1 −1
Original line number Diff line number Diff line
@@ -1921,7 +1921,7 @@ static void binder_deferred_fd_close(int fd) 
	if (!twcb)

		return;

	init_task_work(&twcb->twork, binder_do_fd_close);

	twcb->file = close_fd_get_file(fd);

	twcb->file = file_close_fd(fd);

	if (twcb->file) {

		// pin it until binder_do_fd_close(); see comments there

		get_file(twcb->file);

drivers/vdpa/vdpa_user/vduse_dev.c

+1 −1
Original line number Diff line number Diff line
@@ -1157,7 +1157,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, 
			fput(f);

			break;

		}

		ret = receive_fd(f, perm_to_file_flags(entry.perm));

		ret = receive_fd(f, NULL, perm_to_file_flags(entry.perm));

		fput(f);

		break;

	}

fs/file.c

+53 −44
Original line number Diff line number Diff line
@@ -629,19 +629,23 @@ void fd_install(unsigned int fd, struct file *file) 
EXPORT_SYMBOL(fd_install);



/**

 * pick_file - return file associatd with fd

 * file_close_fd_locked - return file associated with fd

 * @files: file struct to retrieve file from

 * @fd: file descriptor to retrieve file for

 *

 * Doesn't take a separate reference count.

 *

 * Context: files_lock must be held.

 *

 * Returns: The file associated with @fd (NULL if @fd is not open)

 */

static struct file *pick_file(struct files_struct *files, unsigned fd)

struct file *file_close_fd_locked(struct files_struct *files, unsigned fd)

{

	struct fdtable *fdt = files_fdtable(files);

	struct file *file;



	lockdep_assert_held(&files->file_lock);



	if (fd >= fdt->max_fds)

		return NULL;
@@ -660,7 +664,7 @@ int close_fd(unsigned fd) 
	struct file *file;



	spin_lock(&files->file_lock);

	file = pick_file(files, fd);

	file = file_close_fd_locked(files, fd);

	spin_unlock(&files->file_lock);

	if (!file)

		return -EBADF;
@@ -707,7 +711,7 @@ static inline void __range_close(struct files_struct *files, unsigned int fd, 
	max_fd = min(max_fd, n);



	for (; fd <= max_fd; fd++) {

		file = pick_file(files, fd);

		file = file_close_fd_locked(files, fd);

		if (file) {

			spin_unlock(&files->file_lock);

			filp_close(file, files);
@@ -795,26 +799,21 @@ int __close_range(unsigned fd, unsigned max_fd, unsigned int flags) 
	return 0;

}



/*

 * See close_fd_get_file() below, this variant assumes current->files->file_lock

 * is held.

 */

struct file *__close_fd_get_file(unsigned int fd)

{

	return pick_file(current->files, fd);

}



/*

 * variant of close_fd that gets a ref on the file for later fput.

 * The caller must ensure that filp_close() called on the file.

/**

 * file_close_fd - return file associated with fd

 * @fd: file descriptor to retrieve file for

 *

 * Doesn't take a separate reference count.

 *

 * Returns: The file associated with @fd (NULL if @fd is not open)

 */

struct file *close_fd_get_file(unsigned int fd)

struct file *file_close_fd(unsigned int fd)

{

	struct files_struct *files = current->files;

	struct file *file;



	spin_lock(&files->file_lock);

	file = pick_file(files, fd);

	file = file_close_fd_locked(files, fd);

	spin_unlock(&files->file_lock);



	return file;
@@ -959,31 +958,45 @@ static inline struct file *__fget_files_rcu(struct files_struct *files, 
		struct file *file;

		struct fdtable *fdt = rcu_dereference_raw(files->fdt);

		struct file __rcu **fdentry;

		unsigned long nospec_mask;



		if (unlikely(fd >= fdt->max_fds))

			return NULL;



		fdentry = fdt->fd + array_index_nospec(fd, fdt->max_fds);

		/* Mask is a 0 for invalid fd's, ~0 for valid ones */

		nospec_mask = array_index_mask_nospec(fd, fdt->max_fds);



		/*

		 * Ok, we have a file pointer. However, because we do

		 * this all locklessly under RCU, we may be racing with

		 * that file being closed.

		 *

		 * Such a race can take two forms:

		 *

		 *  (a) the file ref already went down to zero and the

		 *      file hasn't been reused yet or the file count

		 *      isn't zero but the file has already been reused.

		 * fdentry points to the 'fd' offset, or fdt->fd[0].

		 * Loading from fdt->fd[0] is always safe, because the

		 * array always exists.

		 */

		file = __get_file_rcu(fdentry);

		fdentry = fdt->fd + (fd & nospec_mask);



		/* Do the load, then mask any invalid result */

		file = rcu_dereference_raw(*fdentry);

		file = (void *)(nospec_mask & (unsigned long)file);

		if (unlikely(!file))

			return NULL;



		if (unlikely(IS_ERR(file)))

		/*

		 * Ok, we have a file pointer that was valid at

		 * some point, but it might have become stale since.

		 *

		 * We need to confirm it by incrementing the refcount

		 * and then check the lookup again.

		 *

		 * atomic_long_inc_not_zero() gives us a full memory

		 * barrier. We only really need an 'acquire' one to

		 * protect the loads below, but we don't have that.

		 */

		if (unlikely(!atomic_long_inc_not_zero(&file->f_count)))

			continue;



		/*

		 * Such a race can take two forms:

		 *

		 *  (a) the file ref already went down to zero and the

		 *      file hasn't been reused yet or the file count

		 *      isn't zero but the file has already been reused.

		 *

		 *  (b) the file table entry has changed under us.

		 *       Note that we don't need to re-check the 'fdt->fd'

		 *       pointer having changed, because it always goes
@@ -991,7 +1004,8 @@ static inline struct file *__fget_files_rcu(struct files_struct *files, 
		 *

		 * If so, we need to put our ref and try again.

		 */

		if (unlikely(rcu_dereference_raw(files->fdt) != fdt)) {

		if (unlikely(file != rcu_dereference_raw(*fdentry)) ||

		    unlikely(rcu_dereference_raw(files->fdt) != fdt)) {

			fput(file);

			continue;

		}
@@ -1128,13 +1142,13 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask) 
	 * atomic_read_acquire() pairs with atomic_dec_and_test() in

	 * put_files_struct().

	 */

	if (atomic_read_acquire(&files->count) == 1) {

	if (likely(atomic_read_acquire(&files->count) == 1)) {

		file = files_lookup_fd_raw(files, fd);

		if (!file || unlikely(file->f_mode & mask))

			return 0;

		return (unsigned long)file;

	} else {

		file = __fget(fd, mask);

		file = __fget_files(files, fd, mask);

		if (!file)

			return 0;

		return FDPUT_FPUT | (unsigned long)file;
@@ -1282,7 +1296,7 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) 
}



/**

 * __receive_fd() - Install received file into file descriptor table

 * receive_fd() - Install received file into file descriptor table

 * @file: struct file that was received from another process

 * @ufd: __user pointer to write new fd number to

 * @o_flags: the O_* flags to apply to the new fd entry
@@ -1296,7 +1310,7 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) 
 *

 * Returns newly install fd or -ve on error.

 */

int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags)

int receive_fd(struct file *file, int __user *ufd, unsigned int o_flags)

{

	int new_fd;

	int error;
@@ -1321,6 +1335,7 @@ int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags) 
	__receive_sock(file);

	return new_fd;

}

EXPORT_SYMBOL_GPL(receive_fd);



int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags)

{
@@ -1336,12 +1351,6 @@ int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags) 
	return new_fd;

}



int receive_fd(struct file *file, unsigned int o_flags)

{

	return __receive_fd(file, NULL, o_flags);

}

EXPORT_SYMBOL_GPL(receive_fd);



static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags)

{

	int err = -EBADF;

fs/file_table.c

+7 −15
Original line number Diff line number Diff line
@@ -75,18 +75,6 @@ static inline void file_free(struct file *f) 
	}

}



void release_empty_file(struct file *f)

{

	WARN_ON_ONCE(f->f_mode & (FMODE_BACKING | FMODE_OPENED));

	if (atomic_long_dec_and_test(&f->f_count)) {

		security_file_free(f);

		put_cred(f->f_cred);

		if (likely(!(f->f_mode & FMODE_NOACCOUNT)))

			percpu_counter_dec(&nr_files);

		kmem_cache_free(filp_cachep, f);

	}

}



/*

 * Return the total number of open files in the system

 */
@@ -419,7 +407,7 @@ static void delayed_fput(struct work_struct *unused) 


static void ____fput(struct callback_head *work)

{

	__fput(container_of(work, struct file, f_rcuhead));

	__fput(container_of(work, struct file, f_task_work));

}



/*
@@ -445,9 +433,13 @@ void fput(struct file *file) 
	if (atomic_long_dec_and_test(&file->f_count)) {

		struct task_struct *task = current;



		if (unlikely(!(file->f_mode & (FMODE_BACKING | FMODE_OPENED)))) {

			file_free(file);

			return;

		}

		if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) {

			init_task_work(&file->f_rcuhead, ____fput);

			if (!task_work_add(task, &file->f_rcuhead, TWA_RESUME))

			init_task_work(&file->f_task_work, ____fput);

			if (!task_work_add(task, &file->f_task_work, TWA_RESUME))

				return;

			/*

			 * After this task has run exit_task_work(),

fs/internal.h

+1 −2
Original line number Diff line number Diff line
@@ -94,7 +94,6 @@ extern void chroot_fs_refs(const struct path *, const struct path *); 
struct file *alloc_empty_file(int flags, const struct cred *cred);

struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);

struct file *alloc_empty_backing_file(int flags, const struct cred *cred);

void release_empty_file(struct file *f);



static inline void file_put_write_access(struct file *file)

{
@@ -180,7 +179,7 @@ extern struct file *do_file_open_root(const struct path *, 
		const char *, const struct open_flags *);

extern struct open_how build_open_how(int flags, umode_t mode);

extern int build_open_flags(const struct open_how *how, struct open_flags *op);

extern struct file *__close_fd_get_file(unsigned int fd);

struct file *file_close_fd_locked(struct files_struct *files, unsigned fd);



long do_sys_ftruncate(unsigned int fd, loff_t length, int small);

int chmod_common(const struct path *path, umode_t mode);