fs: relocate and tidy up ihold()

The placement was illogical, move it next to igrab().

Take this opportunity to add docs and an assert on the refcount. While
its modification remains gated with a WARN_ON, the new assert will also
dump the inode state which might aid debugging.

No functional changes.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260421182538.1215894-3-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/inode.c b/fs/inode.c
index 3338ef2710999936f0c05c3d4dda8be1fda9baca..ab9573355f3b8858ac94bd9482f6bc2711fa4c12 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -518,15 +518,6 @@ static void init_once(void *foo)
        inode_init_once(inode);
 }
 
-/*
- * get additional reference to inode; caller must already hold one.
- */
-void ihold(struct inode *inode)
-{
-       WARN_ON(atomic_inc_return(&inode->i_count) < 2);
-}
-EXPORT_SYMBOL(ihold);
-
 struct wait_queue_head *inode_bit_waitqueue(struct wait_bit_queue_entry *wqe,
                                            struct inode *inode, u32 bit)
 {
@@ -1572,6 +1563,17 @@ ino_t iunique(struct super_block *sb, ino_t max_reserved)
 }
 EXPORT_SYMBOL(iunique);
 
+/**
+ * ihold - get a reference on the inode, provided you already have one
+ * @inode:     inode to operate on
+ */
+void ihold(struct inode *inode)
+{
+       VFS_BUG_ON_INODE(icount_read_once(inode) < 1, inode);
+       WARN_ON(atomic_inc_return(&inode->i_count) < 2);
+}
+EXPORT_SYMBOL(ihold);
+
 struct inode *igrab(struct inode *inode)
 {
        spin_lock(&inode->i_lock);