[RFC v2 42/83] Log operation: link change append.

Andiry Xu
2018-03-10T18:21:10Z

NOVA appends link change entries to atomically update link count and ctime.
This occurs in link, unlink and rmdir.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/log.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/nova/log.h | 3 +++
2 files changed, 55 insertions(+)

diff --git a/fs/nova/log.c b/fs/nova/log.c
index f85b63e..4638ccf 100644
--- a/fs/nova/log.c
+++ b/fs/nova/log.c
@@ -51,6 +51,25 @@ static void nova_update_setattr_entry(struct inode *inode,
nova_persist_entry(entry);
}

+static void nova_update_link_change_entry(struct inode *inode,
+ struct nova_link_change_entry *entry,
+ struct nova_log_entry_info *entry_info)
+{
+ struct nova_inode_info *si = NOVA_I(inode);
+ struct nova_inode_info_header *sih = &si->header;
+
+ entry->entry_type = LINK_CHANGE;
+ entry->epoch_id = cpu_to_le64(entry_info->epoch_id);
+ entry->trans_id = cpu_to_le64(entry_info->trans_id);
+ entry->invalid = 0;
+ entry->links = cpu_to_le16(inode->i_nlink);
+ entry->ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+ entry->flags = cpu_to_le32(sih->i_flags);
+ entry->generation = cpu_to_le32(inode->i_generation);
+
+ nova_persist_entry(entry);
+}
+
static int nova_update_write_entry(struct super_block *sb,
struct nova_file_write_entry *entry,
struct nova_log_entry_info *entry_info)
@@ -150,6 +169,7 @@ static int nova_update_log_entry(struct super_block *sb, struct inode *inode,
nova_update_setattr_entry(inode, entry, entry_info);
break;
case LINK_CHANGE:
+ nova_update_link_change_entry(inode, entry, entry_info);
break;
default:
break;
@@ -230,6 +250,38 @@ static int nova_append_setattr_entry(struct super_block *sb,
return ret;
}

+/* Returns new tail after append */
+int nova_append_link_change_entry(struct super_block *sb,
+ struct nova_inode *pi, struct inode *inode,
+ struct nova_inode_update *update, u64 *old_linkc, u64 epoch_id)
+{
+ struct nova_inode_info *si = NOVA_I(inode);
+ struct nova_inode_info_header *sih = &si->header;
+ struct nova_log_entry_info entry_info;
+ int ret = 0;
+ timing_t append_time;
+
+ NOVA_START_TIMING(append_link_change_t, append_time);
+
+ entry_info.type = LINK_CHANGE;
+ entry_info.update = update;
+ entry_info.epoch_id = epoch_id;
+ entry_info.trans_id = sih->trans_id;
+
+ ret = nova_append_log_entry(sb, pi, inode, sih, &entry_info);
+ if (ret) {
+ nova_err(sb, "%s failed\n", __func__);
+ goto out;
+ }
+
+ *old_linkc = sih->last_link_change;
+ sih->last_link_change = entry_info.curr_p;
+ sih->trans_id++;
+out:
+ NOVA_END_TIMING(append_link_change_t, append_time);
+ return ret;
+}
+
/*
* Append a nova_file_write_entry to the current nova_inode_log_page.
* blocknr and start_blk are pgoff.
diff --git a/fs/nova/log.h b/fs/nova/log.h
index db7a72e..f36f4a3 100644
--- a/fs/nova/log.h
+++ b/fs/nova/log.h
@@ -364,6 +364,9 @@ static inline int is_dir_init_entry(struct super_block *sb,
}

+int nova_append_link_change_entry(struct super_block *sb,
+ struct nova_inode *pi, struct inode *inode,
+ struct nova_inode_update *update, u64 *old_linkc, u64 epoch_id);
int nova_append_file_write_entry(struct super_block *sb, struct nova_inode *pi,
struct inode *inode, struct nova_file_write_item *item,
struct nova_inode_update *update);
--
2.7.4