mark struct file that had write access grabbed by open() (83f936c7) · Commits · 戴 / test

fs/file_table.c

+4 −33

Original line number	Diff line number	Diff line
		@@ -177,43 +177,12 @@ struct file alloc_file(struct path path, fmode_t mode,
		file->f_mapping = path->dentry->d_inode->i_mapping;
		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)) {
		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;

		if (special_file(inode->i_mode))
		return;

		put_write_access(inode);
		__mnt_drop_write(mnt);
		}

		/* the real guts of fput() - releasing the last reference to file
		*/
		static void __fput(struct file *file)
		@@ -248,8 +217,10 @@ 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;

fs/namespace.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -414,9 +414,7 @@ EXPORT_SYMBOL_GPL(mnt_clone_write);
		*/
		int __mnt_want_write_file(struct file *file)
		{
		struct inode *inode = file_inode(file);

		if (!(file->f_mode & FMODE_WRITE) \|\| special_file(inode->i_mode))
		if (!(file->f_mode & FMODE_WRITER))
		return __mnt_want_write(file->f_path.mnt);
		else
		return mnt_clone_write(file->f_path.mnt);

fs/open.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -670,6 +670,7 @@ static int do_dentry_open(struct file *f,
		put_write_access(inode);
		goto cleanup_file;
		}
		f->f_mode \|= FMODE_WRITER;
		}

		f->f_mapping = inode->i_mapping;
		@@ -715,12 +716,10 @@ static int do_dentry_open(struct file *f,

		cleanup_all:
		fops_put(f->f_op);
		if (f->f_mode & FMODE_WRITE) {
		if (!special_file(inode->i_mode)) {
		if (f->f_mode & FMODE_WRITER) {
		put_write_access(inode);
		__mnt_drop_write(f->f_path.mnt);
		}
		}
		cleanup_file:
		path_put(&f->f_path);
		f->f_path.mnt = NULL;

include/linux/fs.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -125,6 +125,8 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,

		/* File needs atomic accesses to f_pos */
		#define FMODE_ATOMIC_POS ((__force fmode_t)0x8000)
		/* Write access to underlying fs */
		#define FMODE_WRITER ((__force fmode_t)0x10000)

		/* File was opened by fanotify and shouldn't generate fanotify events */
		#define FMODE_NONOTIFY ((__force fmode_t)0x1000000)

Admin message