[RFC v2 47/83] Dir: Add initial dentries when initializing a directory inode log.

Andiry Xu
2018-03-10T18:33:14Z

For root directory and newly created directory via mkdir(),
we append . and .. dentries to the directory inode log.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/dir.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/nova/nova.h | 2 ++
fs/nova/super.c | 5 ++++
3 files changed, 89 insertions(+)

diff --git a/fs/nova/dir.c b/fs/nova/dir.c
index 5bea57a..377d2da 100644
--- a/fs/nova/dir.c
+++ b/fs/nova/dir.c
@@ -139,3 +139,85 @@ void nova_delete_dir_tree(struct super_block *sb,

NOVA_END_TIMING(delete_dir_tree_t, delete_time);
}
+
+/* ========================= Entry operations ============================= */
+
+static unsigned int nova_init_dentry(struct super_block *sb,
+ struct nova_dentry *de_entry, u64 self_ino, u64 parent_ino,
+ u64 epoch_id)
+{
+ void *start = de_entry;
+ struct nova_inode_log_page *curr_page = start;
+ unsigned int length;
+ unsigned short de_len;
+
+ de_len = NOVA_DIR_LOG_REC_LEN(1);
+ memset(de_entry, 0, de_len);
+ de_entry->entry_type = DIR_LOG;
+ de_entry->epoch_id = epoch_id;
+ de_entry->trans_id = 0;
+ de_entry->ino = cpu_to_le64(self_ino);
+ de_entry->name_len = 1;
+ de_entry->de_len = cpu_to_le16(de_len);
+ de_entry->mtime = timespec_trunc(current_kernel_time(),
+ sb->s_time_gran).tv_sec;
+
+ de_entry->links_count = 1;
+ strncpy(de_entry->name, ".\0", 2);
+ nova_persist_entry(de_entry);
+
+ length = de_len;
+
+ de_entry = (struct nova_dentry *)((char *)de_entry + length);
+ de_len = NOVA_DIR_LOG_REC_LEN(2);
+ memset(de_entry, 0, de_len);
+ de_entry->entry_type = DIR_LOG;
+ de_entry->epoch_id = epoch_id;
+ de_entry->trans_id = 0;
+ de_entry->ino = cpu_to_le64(parent_ino);
+ de_entry->name_len = 2;
+ de_entry->de_len = cpu_to_le16(de_len);
+ de_entry->mtime = timespec_trunc(current_kernel_time(),
+ sb->s_time_gran).tv_sec;
+
+ de_entry->links_count = 2;
+ strncpy(de_entry->name, "..\0", 3);
+ nova_persist_entry(de_entry);
+ length += de_len;
+
+ nova_set_page_num_entries(sb, curr_page, 2, 1);
+
+ nova_flush_buffer(start, length, 0);
+ return length;
+}
+
+/* Append . and .. entries */
+int nova_append_dir_init_entries(struct super_block *sb,
+ struct nova_inode *pi, u64 self_ino, u64 parent_ino, u64 epoch_id)
+{
+ struct nova_inode_info_header sih;
+ int allocated;
+ u64 new_block;
+ unsigned int length;
+ struct nova_dentry *de_entry;
+
+ sih.ino = self_ino;
+ sih.i_blk_type = NOVA_DEFAULT_BLOCK_TYPE;
+
+ allocated = nova_allocate_inode_log_pages(sb, &sih, 1, &new_block,
+ ANY_CPU, 0);
+ if (allocated != 1) {
+ nova_err(sb, "ERROR: no inode log page available\n");
+ return -ENOMEM;
+ }
+
+ pi->log_tail = pi->log_head = new_block;
+
+ de_entry = (struct nova_dentry *)nova_get_block(sb, new_block);
+
+ length = nova_init_dentry(sb, de_entry, self_ino, parent_ino, epoch_id);
+
+ nova_update_tail(pi, new_block + length);
+
+ return 0;
+}
diff --git a/fs/nova/nova.h b/fs/nova/nova.h
index 3890479..a94f44d 100644
--- a/fs/nova/nova.h
+++ b/fs/nova/nova.h
@@ -458,6 +458,8 @@ void nova_delete_dir_tree(struct super_block *sb,
struct nova_dentry *nova_find_dentry(struct super_block *sb,
struct nova_inode *pi, struct inode *inode, const char *name,
unsigned long name_len);
+int nova_append_dir_init_entries(struct super_block *sb,
+ struct nova_inode *pi, u64 self_ino, u64 parent_ino, u64 epoch_id);

/* rebuild.c */
int nova_rebuild_inode(struct super_block *sb, struct nova_inode_info *si,
diff --git a/fs/nova/super.c b/fs/nova/super.c
index 216d396..1e67062 100644
--- a/fs/nova/super.c
+++ b/fs/nova/super.c
@@ -349,6 +349,7 @@ static struct nova_inode *nova_init(struct super_block *sb,
struct nova_inode *root_i, *pi;
struct nova_super_block *super;
struct nova_sb_info *sbi = NOVA_SB(sb);
+ u64 epoch_id;
timing_t init_time;

NOVA_START_TIMING(new_init_t, init_time);
@@ -415,6 +416,10 @@ static struct nova_inode *nova_init(struct super_block *sb,

nova_flush_buffer(root_i, sizeof(*root_i), false);

+ epoch_id = nova_get_epoch_id(sb);
+ nova_append_dir_init_entries(sb, root_i, NOVA_ROOT_INO,
+ NOVA_ROOT_INO, epoch_id);
+
PERSISTENT_MARK();
PERSISTENT_BARRIER();
nova_info("NOVA initialization finish\n");
--
2.7.4