f2fs: add F2FS_INLINE_DOTS to recover missing dot dentries
If f2fs was corrupted with missing dot dentries, it needs to recover them after
fsck.f2fs detection.
The underlying precedure is:
1. The fsck.f2fs remains F2FS_INLINE_DOTS flag in directory inode, if it detects
missing dot dentries.
2. When f2fs looks up the corrupted directory, it triggers f2fs_add_link with
proper inode numbers and their dot and dotdot names.
3. Once f2fs recovers the directory without errors, it removes F2FS_INLINE_DOTS
finally.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 1e2ae21..8055e30 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -187,6 +187,44 @@
return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
}
+static int __recover_dot_dentries(struct inode *dir, nid_t pino)
+{
+ struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+ struct qstr dot = QSTR_INIT(".", 1);
+ struct qstr dotdot = QSTR_INIT("..", 2);
+ struct f2fs_dir_entry *de;
+ struct page *page;
+ int err = 0;
+
+ f2fs_lock_op(sbi);
+
+ de = f2fs_find_entry(dir, &dot, &page);
+ if (de) {
+ f2fs_dentry_kunmap(dir, page);
+ f2fs_put_page(page, 0);
+ } else {
+ err = __f2fs_add_link(dir, &dot, NULL, dir->i_ino, S_IFDIR);
+ if (err)
+ goto out;
+ }
+
+ de = f2fs_find_entry(dir, &dotdot, &page);
+ if (de) {
+ f2fs_dentry_kunmap(dir, page);
+ f2fs_put_page(page, 0);
+ } else {
+ err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
+ }
+out:
+ if (!err) {
+ clear_inode_flag(F2FS_I(dir), FI_INLINE_DOTS);
+ mark_inode_dirty(dir);
+ }
+
+ f2fs_unlock_op(sbi);
+ return err;
+}
+
static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
@@ -206,6 +244,16 @@
inode = f2fs_iget(dir->i_sb, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
+
+ if (f2fs_has_inline_dots(inode)) {
+ int err;
+
+ err = __recover_dot_dentries(inode, dir->i_ino);
+ if (err) {
+ iget_failed(inode);
+ return ERR_PTR(err);
+ }
+ }
}
return d_splice_alias(inode, dentry);