Commit ea5dc046 authored by Jeffle Xu's avatar Jeffle Xu Committed by David Howells
Browse files

cachefiles: unmark inode in use in error path 



Unmark inode in use if error encountered. If the in-use flag leakage
occurs in cachefiles_open_file(), Cachefiles will complain "Inode
already in use" when later another cookie with the same index key is
looked up.

If the in-use flag leakage occurs in cachefiles_create_tmpfile(), though
the "Inode already in use" warning won't be triggered, fix the leakage
anyway.

Reported-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Fixes: 1f08c925 ("cachefiles: Implement backing file wrangling")
Signed-off-by: default avatarJeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://listman.redhat.com/archives/linux-cachefs/2022-March/006615.html # v1
Link: https://listman.redhat.com/archives/linux-cachefs/2022-March/006618.html # v2
parent 42e7a03d

fs/cachefiles/namei.c

+24 −9
Original line number Diff line number Diff line
@@ -57,6 +57,16 @@ static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 
	trace_cachefiles_mark_inactive(object, inode);

}



static void cachefiles_do_unmark_inode_in_use(struct cachefiles_object *object,

					      struct dentry *dentry)

{

	struct inode *inode = d_backing_inode(dentry);



	inode_lock(inode);

	__cachefiles_unmark_inode_in_use(object, dentry);

	inode_unlock(inode);

}



/*

 * Unmark a backing inode and tell cachefilesd that there's something that can

 * be culled.
@@ -68,9 +78,7 @@ void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 
	struct inode *inode = file_inode(file);



	if (inode) {

		inode_lock(inode);

		__cachefiles_unmark_inode_in_use(object, file->f_path.dentry);

		inode_unlock(inode);

		cachefiles_do_unmark_inode_in_use(object, file->f_path.dentry);



		if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {

			atomic_long_add(inode->i_blocks, &cache->b_released);
@@ -484,7 +492,7 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object) 
				object, d_backing_inode(path.dentry), ret,

				cachefiles_trace_trunc_error);

			file = ERR_PTR(ret);

			goto out_dput;

			goto out_unuse;

		}

	}
@@ -494,15 +502,20 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object) 
		trace_cachefiles_vfs_error(object, d_backing_inode(path.dentry),

					   PTR_ERR(file),

					   cachefiles_trace_open_error);

		goto out_dput;

		goto out_unuse;

	}

	if (unlikely(!file->f_op->read_iter) ||

	    unlikely(!file->f_op->write_iter)) {

		fput(file);

		pr_notice("Cache does not support read_iter and write_iter\n");

		file = ERR_PTR(-EINVAL);

		goto out_unuse;

	}



	goto out_dput;



out_unuse:

	cachefiles_do_unmark_inode_in_use(object, path.dentry);

out_dput:

	dput(path.dentry);

out:
@@ -590,14 +603,16 @@ static bool cachefiles_open_file(struct cachefiles_object *object, 
check_failed:

	fscache_cookie_lookup_negative(object->cookie);

	cachefiles_unmark_inode_in_use(object, file);

	if (ret == -ESTALE) {

	fput(file);

	dput(dentry);

	if (ret == -ESTALE)

		return cachefiles_create_file(object);

	}

	return false;



error_fput:

	fput(file);

error:

	cachefiles_do_unmark_inode_in_use(object, dentry);

	dput(dentry);

	return false;

}