From: Andiry Xu <jix...@cs.ucsd.edu>

NOVA reads the directory by traversing the log and reports
the valid dentries. Valid dentris have inode number greater than zero,
meaning it's a create dentry.

Signed-off-by: Andiry Xu <jix...@cs.ucsd.edu>
---
 fs/nova/dir.c   | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/nova/inode.c |   2 +
 fs/nova/nova.h  |   1 +
 3 files changed, 156 insertions(+)

diff --git a/fs/nova/dir.c b/fs/nova/dir.c
index 377d2da..35a66f9 100644
--- a/fs/nova/dir.c
+++ b/fs/nova/dir.c
@@ -221,3 +221,156 @@ int nova_append_dir_init_entries(struct super_block *sb,
 
        return 0;
 }
+
+static u64 nova_find_next_dentry_addr(struct super_block *sb,
+       struct nova_inode_info_header *sih, u64 pos)
+{
+       struct nova_sb_info *sbi = NOVA_SB(sb);
+       struct nova_file_write_entry *entry = NULL;
+       struct nova_file_write_entry *entries[1];
+       int nr_entries;
+       u64 addr = 0;
+
+       nr_entries = radix_tree_gang_lookup(&sih->tree,
+                                       (void **)entries, pos, 1);
+       if (nr_entries == 1) {
+               entry = entries[0];
+               addr = nova_get_addr_off(sbi, entry);
+       }
+
+       return addr;
+}
+
+static int nova_readdir(struct file *file, struct dir_context *ctx)
+{
+       struct inode *inode = file_inode(file);
+       struct super_block *sb = inode->i_sb;
+       struct nova_inode *pidir;
+       struct nova_inode_info *si = NOVA_I(inode);
+       struct nova_inode_info_header *sih = &si->header;
+       struct nova_inode *child_pi;
+       struct nova_inode *prev_child_pi = NULL;
+       struct nova_dentry *entry = NULL;
+       struct nova_dentry *prev_entry = NULL;
+       unsigned short de_len;
+       u64 pi_addr;
+       unsigned long pos = 0;
+       ino_t ino;
+       void *addr;
+       u64 curr_p;
+       u8 type;
+       int ret = 0;
+       timing_t readdir_time;
+
+       NOVA_START_TIMING(readdir_t, readdir_time);
+       pidir = nova_get_inode(sb, inode);
+       nova_dbgv("%s: ino %llu, size %llu, pos 0x%llx\n",
+                       __func__, (u64)inode->i_ino,
+                       pidir->i_size, ctx->pos);
+
+       if (sih->log_head == 0) {
+               nova_err(sb, "Dir %lu log is NULL!\n", inode->i_ino);
+               ret = -ENOSPC;
+               goto out;
+       }
+
+       pos = ctx->pos;
+
+       if (pos == 0)
+               curr_p = sih->log_head;
+       else if (pos == READDIR_END)
+               goto out;
+       else {
+               curr_p = nova_find_next_dentry_addr(sb, sih, pos);
+               if (curr_p == 0)
+                       goto out;
+       }
+
+       while (curr_p != sih->log_tail) {
+               if (goto_next_page(sb, curr_p))
+                       curr_p = next_log_page(sb, curr_p);
+
+
+               if (curr_p == 0) {
+                       nova_err(sb, "Dir %lu log is NULL!\n", inode->i_ino);
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               addr = (void *)nova_get_block(sb, curr_p);
+               type = nova_get_entry_type(addr);
+               switch (type) {
+               case SET_ATTR:
+                       curr_p += sizeof(struct nova_setattr_logentry);
+                       continue;
+               case LINK_CHANGE:
+                       curr_p += sizeof(struct nova_link_change_entry);
+                       continue;
+               case DIR_LOG:
+                       break;
+               default:
+                       nova_err(sb, "%s: unknown type %d, 0x%llx\n",
+                                __func__, type, curr_p);
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               entry = (struct nova_dentry *)nova_get_block(sb, curr_p);
+               nova_dbgv("curr_p: 0x%llx, type %d, ino %llu, name %s, namelen 
%u, rec len %u\n",
+                         curr_p, entry->entry_type, le64_to_cpu(entry->ino),
+                         entry->name, entry->name_len,
+                         le16_to_cpu(entry->de_len));
+
+               de_len = le16_to_cpu(entry->de_len);
+               if (entry->ino > 0 && entry->invalid == 0
+                                       && entry->reassigned == 0) {
+                       ino = __le64_to_cpu(entry->ino);
+                       pos = BKDRHash(entry->name, entry->name_len);
+
+                       ret = nova_get_inode_address(sb, ino,
+                                                    &pi_addr, 0);
+                       if (ret) {
+                               nova_dbg("%s: get child inode %lu address 
failed %d\n",
+                                        __func__, ino, ret);
+                               ctx->pos = READDIR_END;
+                               goto out;
+                       }
+
+                       child_pi = nova_get_block(sb, pi_addr);
+                       nova_dbgv("ctx: ino %llu, name %s, name_len %u, de_len 
%u\n",
+                               (u64)ino, entry->name, entry->name_len,
+                               entry->de_len);
+                       if (prev_entry && !dir_emit(ctx, prev_entry->name,
+                               prev_entry->name_len, ino,
+                               IF2DT(le16_to_cpu(prev_child_pi->i_mode)))) {
+                               nova_dbgv("Here: pos %llu\n", ctx->pos);
+                               ret = 0;
+                               goto out;
+                       }
+                       prev_entry = entry;
+
+                       prev_child_pi = child_pi;
+               }
+               ctx->pos = pos;
+               curr_p += de_len;
+       }
+
+       if (prev_entry && !dir_emit(ctx, prev_entry->name,
+                       prev_entry->name_len, ino,
+                       IF2DT(le16_to_cpu(prev_child_pi->i_mode))))
+               return 0;
+
+       ctx->pos = READDIR_END;
+       ret = 0;
+out:
+       NOVA_END_TIMING(readdir_t, readdir_time);
+       nova_dbgv("%s return\n", __func__);
+       return ret;
+}
+
+const struct file_operations nova_dir_operations = {
+       .llseek         = generic_file_llseek,
+       .read           = generic_read_dir,
+       .iterate        = nova_readdir,
+       .fsync          = noop_fsync,
+};
diff --git a/fs/nova/inode.c b/fs/nova/inode.c
index 15517cc..41417e3 100644
--- a/fs/nova/inode.c
+++ b/fs/nova/inode.c
@@ -181,6 +181,7 @@ static int nova_read_inode(struct super_block *sb, struct 
inode *inode,
        case S_IFREG:
                break;
        case S_IFDIR:
+               inode->i_fop = &nova_dir_operations;
                break;
        case S_IFLNK:
                break;
@@ -625,6 +626,7 @@ struct inode *nova_new_vfs_inode(enum nova_new_inode_type 
type,
                inode->i_mapping->a_ops = &nova_aops_dax;
                break;
        case TYPE_MKDIR:
+               inode->i_fop = &nova_dir_operations;
                inode->i_mapping->a_ops = &nova_aops_dax;
                set_nlink(inode, 2);
                break;
diff --git a/fs/nova/nova.h b/fs/nova/nova.h
index a94f44d..ed269fe 100644
--- a/fs/nova/nova.h
+++ b/fs/nova/nova.h
@@ -447,6 +447,7 @@ nova_get_blocknr(struct super_block *sb, u64 block, 
unsigned short btype)
 /* ====================================================== */
 
 /* dir.c */
+extern const struct file_operations nova_dir_operations;
 int nova_insert_dir_radix_tree(struct super_block *sb,
        struct nova_inode_info_header *sih, const char *name,
        int namelen, struct nova_dentry *direntry);
-- 
2.7.4

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