Since we are no longer using refcnt for kernfs_open_node instances, rename
kernfs_put_open_node to kernfs_unlink_open_file to reflect this change.
Also update function description and inline comments accordingly.
Signed-off-by: Imran Khan <[email protected]>
---
fs/kernfs/file.c | 28 +++++++++++++++++++---------
1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index aea6968c979e..e3abfa843879 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -552,18 +552,19 @@ static int kernfs_get_open_node(struct kernfs_node *kn,
}
/**
- * kernfs_put_open_node - put kernfs_open_node
+ * kernfs_unlink_open_file - Unlink @of from @kn.
+ *
* @kn: target kernfs_node
* @of: associated kernfs_open_file
*
- * Put @kn->attr.open and unlink @of from the files list. If
- * list of associated open files becomes empty, disassociate and
- * free kernfs_open_node.
+ * Unlink @of from list of @kn's associated open files. If list of
+ * associated open files becomes empty, disassociate and free
+ * kernfs_open_node.
*
* LOCKING:
* None.
*/
-static void kernfs_put_open_node(struct kernfs_node *kn,
+static void kernfs_unlink_open_file(struct kernfs_node *kn,
struct kernfs_open_file *of)
{
struct kernfs_open_node *on = kn->attr.open;
@@ -703,7 +704,7 @@ static int kernfs_fop_open(struct inode *inode, struct file *file)
return 0;
err_put_node:
- kernfs_put_open_node(kn, of);
+ kernfs_unlink_open_file(kn, of);
err_seq_release:
seq_release(inode, file);
err_free:
@@ -749,7 +750,7 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp)
mutex_unlock(&kernfs_open_file_mutex);
}
- kernfs_put_open_node(kn, of);
+ kernfs_unlink_open_file(kn, of);
seq_release(inode, filp);
kfree(of->prealloc_buf);
kfree(of);
@@ -765,8 +766,15 @@ void kernfs_drain_open_files(struct kernfs_node *kn)
if (!(kn->flags & (KERNFS_HAS_MMAP | KERNFS_HAS_RELEASE)))
return;
- on = kn->attr.open;
- if (!on)
+ /*
+ * lockless opportunistic check is safe below because no one is adding to
+ * ->attr.open at this point of time. This check allows early bail out
+ * if ->attr.open is already NULL. kernfs_unlink_open_file makes
+ * ->attr.open NULL only while holding kernfs_open_file_mutex so below
+ * check under kernfs_open_file_mutex will ensure bailing out if
+ * ->attr.open became NULL while waiting for the mutex.
+ */
+ if (!kn->attr.open)
return;
mutex_lock(&kernfs_open_file_mutex);
@@ -775,6 +783,8 @@ void kernfs_drain_open_files(struct kernfs_node *kn)
return;
}
+ on = kn->attr.open;
+
list_for_each_entry(of, &on->files, list) {
struct inode *inode = file_inode(of->file);
--
2.30.2