[PATCH v4 1/5] dcache: export d_find_alias_rcu() for modular filesystems

[Alex Markuze]

The Ceph subvolume quarantine ancestry walk needs to find a dentry
alias under RCU without taking a reference. d_find_alias_rcu() provides
these semantics, but it is not exported, so a modular Ceph client fails
at modpost with an undefined reference to the helper.

Export d_find_alias_rcu() to GPL modules so filesystem modules can use
the existing RCU lookup without changing its lifetime rules.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202610171220.i77KPiw5-lkp@xxxxxxxxx/
Signed-off-by: Alex Markuze <amarkuze@xxxxxxxxxx>
---
 fs/dcache.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/dcache.c b/fs/dcache.c
index 1b1a81f10da6..13ba553081b3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1248,6 +1248,7 @@ struct dentry *d_find_alias_rcu(struct inode *inode)
 	spin_unlock(&inode->i_lock);
 	return de;
 }
+EXPORT_SYMBOL_GPL(d_find_alias_rcu);
 
 /*
  *	Try to kill dentries associated with this inode.