[RFC v2 57/83] Namei: rmdir

Andiry Xu
2018-03-10T18:31:00Z

Similar to unlink.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/namei.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 105 insertions(+)

diff --git a/fs/nova/namei.c b/fs/nova/namei.c
index 360d716..4bf6396 100644
--- a/fs/nova/namei.c
+++ b/fs/nova/namei.c
@@ -437,6 +437,110 @@ static int nova_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
goto out;
}

+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+static int nova_empty_dir(struct inode *inode)
+{
+ struct super_block *sb;
+ struct nova_inode_info *si = NOVA_I(inode);
+ struct nova_inode_info_header *sih = &si->header;
+ struct nova_dentry *entry;
+ unsigned long pos = 0;
+ struct nova_dentry *entries[4];
+ int nr_entries;
+ int i;
+
+ sb = inode->i_sb;
+ nr_entries = radix_tree_gang_lookup(&sih->tree,
+ (void **)entries, pos, 4);
+ if (nr_entries > 2)
+ return 0;
+
+ for (i = 0; i < nr_entries; i++) {
+ entry = entries[i];
+
+ if (!is_dir_init_entry(sb, entry))
+ return 0;
+ }
+
+ return 1;
+}
+
+static int nova_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ struct nova_dentry *de;
+ struct super_block *sb = inode->i_sb;
+ struct nova_inode *pi = nova_get_inode(sb, inode), *pidir;
+ struct nova_inode_update update_dir;
+ struct nova_inode_update update;
+ u64 old_linkc = 0;
+ struct nova_inode_info *si = NOVA_I(inode);
+ struct nova_inode_info_header *sih = &si->header;
+ int err = -ENOTEMPTY;
+ u64 epoch_id;
+ timing_t rmdir_time;
+
+ NOVA_START_TIMING(rmdir_t, rmdir_time);
+ if (!inode)
+ return -ENOENT;
+
+ nova_dbgv("%s: name %s\n", __func__, dentry->d_name.name);
+ pidir = nova_get_inode(sb, dir);
+ if (!pidir)
+ return -EINVAL;
+
+ if (nova_inode_by_name(dir, &dentry->d_name, &de) == 0)
+ return -ENOENT;
+
+ if (!nova_empty_dir(inode))
+ return err;
+
+ nova_dbgv("%s: inode %lu, dir %lu, link %d\n", __func__,
+ inode->i_ino, dir->i_ino, dir->i_nlink);
+
+ if (inode->i_nlink != 2)
+ nova_dbg("empty directory %lu has nlink!=2 (%d), dir %lu",
+ inode->i_ino, inode->i_nlink, dir->i_ino);
+
+ epoch_id = nova_get_epoch_id(sb);
+
+ update_dir.tail = 0;
+ err = nova_remove_dentry(dentry, -1, &update_dir, epoch_id);
+ if (err)
+ goto end_rmdir;
+
+ /*inode->i_version++; */
+ clear_nlink(inode);
+ inode->i_ctime = dir->i_ctime;
+
+ if (dir->i_nlink)
+ drop_nlink(dir);
+
+ nova_delete_dir_tree(sb, sih);
+
+ update.tail = 0;
+ err = nova_append_link_change_entry(sb, pi, inode, &update,
+ &old_linkc, epoch_id);
+ if (err)
+ goto end_rmdir;
+
+ nova_lite_transaction_for_time_and_link(sb, pi, pidir, inode, dir,
+ &update, &update_dir, 1, epoch_id);
+
+ nova_invalidate_link_change_entry(sb, old_linkc);
+ nova_invalidate_dentries(sb, &update_dir);
+
+ NOVA_END_TIMING(rmdir_t, rmdir_time);
+ return err;
+
+end_rmdir:
+ nova_err(sb, "%s return %d\n", __func__, err);
+ NOVA_END_TIMING(rmdir_t, rmdir_time);
+ return err;
+}
+
struct dentry *nova_get_parent(struct dentry *child)
{
struct inode *inode;
@@ -467,5 +571,6 @@ const struct inode_operations nova_dir_inode_operations = {
.link = nova_link,
.unlink = nova_unlink,
.mkdir = nova_mkdir,
+ .rmdir = nova_rmdir,
.mknod = nova_mknod,
};
--
2.7.4