Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 75051206 authored by Daniel Rosenberg's avatar Daniel Rosenberg
Browse files

ANDROID: sdcardfs: Hold i_mutex for i_size_write 



When we call i_size_write, we must be holding i_mutex to avoid
possible lockups on 32 bit/SMP architectures. This is not
necessary on 64 bit architectures.

Change-Id: Ic3b946507c54d81b5c9046f9b57d25d4b0f9feef
Signed-off-by: default avatarDaniel Rosenberg <drosen@google.com>
Bug: 73287721
parent 1a19138f

fs/sdcardfs/file.c

+14 −8
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ static ssize_t sdcardfs_write(struct file *file, const char __user *buf, 
	int err;

	struct file *lower_file;

	struct dentry *dentry = file->f_path.dentry;

	struct inode *inode = dentry->d_inode;



	/* check disk space */

	if (!check_min_free_space(dentry, count, 0)) {
@@ -73,10 +74,12 @@ static ssize_t sdcardfs_write(struct file *file, const char __user *buf, 
	err = vfs_write(lower_file, buf, count, ppos);

	/* update our inode times+sizes upon a successful lower write */

	if (err >= 0) {

		fsstack_copy_inode_size(dentry->d_inode,

					file_inode(lower_file));

		fsstack_copy_attr_times(dentry->d_inode,

					file_inode(lower_file));

		if (sizeof(loff_t) > sizeof(long))

			mutex_lock(&inode->i_mutex);

		fsstack_copy_inode_size(inode, file_inode(lower_file));

		fsstack_copy_attr_times(inode, file_inode(lower_file));

		if (sizeof(loff_t) > sizeof(long))

			mutex_unlock(&inode->i_mutex);

	}



	return err;
@@ -391,6 +394,7 @@ ssize_t sdcardfs_write_iter(struct kiocb *iocb, struct iov_iter *iter) 
{

	int err;

	struct file *file = iocb->ki_filp, *lower_file;

	struct inode *inode = file->f_path.dentry->d_inode;



	lower_file = sdcardfs_lower_file(file);

	if (!lower_file->f_op->write_iter) {
@@ -405,10 +409,12 @@ ssize_t sdcardfs_write_iter(struct kiocb *iocb, struct iov_iter *iter) 
	fput(lower_file);

	/* update upper inode times/sizes as needed */

	if (err >= 0 || err == -EIOCBQUEUED) {

		fsstack_copy_inode_size(file->f_path.dentry->d_inode,

					file_inode(lower_file));

		fsstack_copy_attr_times(file->f_path.dentry->d_inode,

					file_inode(lower_file));

		if (sizeof(loff_t) > sizeof(long))

			mutex_lock(&inode->i_mutex);

		fsstack_copy_inode_size(inode, file_inode(lower_file));

		fsstack_copy_attr_times(inode, file_inode(lower_file));

		if (sizeof(loff_t) > sizeof(long))

			mutex_unlock(&inode->i_mutex);

	}

out:

	return err;