Commit ac45d613 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: fix nlink after unlink 



Anand Avati reports that the following sequence of system calls fail on a fuse
filesystem:


 	create("filename") => 0
 	link("filename", "linkname") => 0
 	unlink("filename") => 0
 	link("linkname", "filename") => -ENOENT ### BUG ###

vfs_link() fails with ENOENT if i_nlink is zero, this is done to prevent
resurrecting already deleted files.

Fuse clears i_nlink on unlink even if there are other links pointing to the
file.

Reported-by: default avatarAnand Avati <avati@redhat.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent 192cfd58

fs/fuse/dir.c

+15 −7
Original line number Diff line number Diff line
@@ -644,13 +644,12 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry) 
	fuse_put_request(fc, req);

	if (!err) {

		struct inode *inode = entry->d_inode;

		struct fuse_inode *fi = get_fuse_inode(inode);



		/*

		 * Set nlink to zero so the inode can be cleared, if the inode

		 * does have more links this will be discovered at the next

		 * lookup/getattr.

		 */

		clear_nlink(inode);

		spin_lock(&fc->lock);

		fi->attr_version = ++fc->attr_version;

		drop_nlink(inode);

		spin_unlock(&fc->lock);

		fuse_invalidate_attr(inode);

		fuse_invalidate_attr(dir);

		fuse_invalidate_entry_cache(entry);
@@ -762,8 +761,17 @@ static int fuse_link(struct dentry *entry, struct inode *newdir, 
	   will reflect changes in the backing inode (link count,

	   etc.)

	*/

	if (!err || err == -EINTR)

	if (!err) {

		struct fuse_inode *fi = get_fuse_inode(inode);



		spin_lock(&fc->lock);

		fi->attr_version = ++fc->attr_version;

		inc_nlink(inode);

		spin_unlock(&fc->lock);

		fuse_invalidate_attr(inode);

	} else if (err == -EINTR) {

		fuse_invalidate_attr(inode);

	}

	return err;

}

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