[PATCH v2 18/50] convert pstore

Al Viro
2025-10-28T00:46:20Z

object creation by d_alloc_name()+d_add() in pstore_mkfile(), removal -
via normal VFS codepaths (with ->unlink() using simple_unlink()) or
in pstore_put_backend_records() via locked_recursive_removal()

Replace d_add() with d_make_persistent()+dput() - that's what really
happens there. The reference that goes into record->dentry is valid
only until the unlink (and explicitly cleared by pstore_unlink()).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/pstore/inode.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index b4e55c90f8dc..71deffcc3356 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -373,7 +373,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
if (!dentry)
return -ENOMEM;

- private->dentry = dentry;
+ private->dentry = dentry; // borrowed
private->record = record;
inode->i_size = private->total_size = size;
inode->i_private = private;
@@ -382,7 +382,8 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
inode_set_mtime_to_ts(inode,
inode_set_ctime_to_ts(inode, record->time));

- d_add(dentry, no_free_ptr(inode));
+ d_make_persistent(dentry, no_free_ptr(inode));
+ dput(dentry);

list_add(&(no_free_ptr(private))->list, &records_list);

@@ -465,7 +466,7 @@ static void pstore_kill_sb(struct super_block *sb)
guard(mutex)(&pstore_sb_lock);
WARN_ON(pstore_sb && pstore_sb != sb);

- kill_litter_super(sb);
+ kill_anon_super(sb);
pstore_sb = NULL;

guard(mutex)(&records_list_lock);
--
2.47.3