[RFC v2 39/83] Log operation: dentry append.

Andiry Xu
2018-03-10T18:35:36Z

NOVA performs atomic log appending by first appending the entry
to the tail of the log, and then atomically update the log tail pointer.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/log.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/nova/log.h | 4 ++
2 files changed, 166 insertions(+)

diff --git a/fs/nova/log.c b/fs/nova/log.c
index f01b7c8..13f9597 100644
--- a/fs/nova/log.c
+++ b/fs/nova/log.c
@@ -20,6 +20,168 @@
#include "inode.h"
#include "log.h"

+static int nova_update_old_dentry(struct super_block *sb,
+ struct inode *dir, struct nova_dentry *dentry,
+ struct nova_log_entry_info *entry_info)
+{
+ unsigned short links_count;
+ int link_change = entry_info->link_change;
+ u64 addr;
+
+ dentry->epoch_id = entry_info->epoch_id;
+ dentry->trans_id = entry_info->trans_id;
+ /* Remove_dentry */
+ dentry->ino = cpu_to_le64(0);
+ dentry->invalid = 1;
+ dentry->mtime = cpu_to_le32(dir->i_mtime.tv_sec);
+
+ links_count = cpu_to_le16(dir->i_nlink);
+ if (links_count == 0 && link_change == -1)
+ links_count = 0;
+ else
+ links_count += link_change;
+ dentry->links_count = cpu_to_le16(links_count);
+
+ addr = nova_get_addr_off(NOVA_SB(sb), dentry);
+ nova_inc_page_invalid_entries(sb, addr);
+
+ nova_persist_entry(dentry);
+
+ return 0;
+}
+
+static int nova_update_new_dentry(struct super_block *sb,
+ struct inode *dir, struct nova_dentry *entry,
+ struct nova_log_entry_info *entry_info)
+{
+ struct dentry *dentry = entry_info->data;
+ unsigned short links_count;
+ int link_change = entry_info->link_change;
+
+ entry->entry_type = DIR_LOG;
+ entry->epoch_id = entry_info->epoch_id;
+ entry->trans_id = entry_info->trans_id;
+ entry->ino = entry_info->ino;
+ entry->name_len = dentry->d_name.len;
+ memcpy_to_pmem_nocache(entry->name, dentry->d_name.name,
+ dentry->d_name.len);
+ entry->name[dentry->d_name.len] = '\0';
+ entry->mtime = cpu_to_le32(dir->i_mtime.tv_sec);
+ //entry->size = cpu_to_le64(dir->i_size);
+
+ links_count = cpu_to_le16(dir->i_nlink);
+ if (links_count == 0 && link_change == -1)
+ links_count = 0;
+ else
+ links_count += link_change;
+ entry->links_count = cpu_to_le16(links_count);
+
+ /* Update actual de_len */
+ entry->de_len = cpu_to_le16(entry_info->file_size);
+
+ nova_persist_entry(entry);
+
+ return 0;
+}
+
+static int nova_update_log_entry(struct super_block *sb, struct inode *inode,
+ void *entry, struct nova_log_entry_info *entry_info)
+{
+ enum nova_entry_type type = entry_info->type;
+
+ switch (type) {
+ case FILE_WRITE:
+ break;
+ case DIR_LOG:
+ if (entry_info->inplace)
+ nova_update_old_dentry(sb, inode, entry, entry_info);
+ else
+ nova_update_new_dentry(sb, inode, entry, entry_info);
+ break;
+ case SET_ATTR:
+ break;
+ case LINK_CHANGE:
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int nova_append_log_entry(struct super_block *sb,
+ struct nova_inode *pi, struct inode *inode,
+ struct nova_inode_info_header *sih,
+ struct nova_log_entry_info *entry_info)
+{
+ void *entry;
+ enum nova_entry_type type = entry_info->type;
+ struct nova_inode_update *update = entry_info->update;
+ u64 tail;
+ u64 curr_p;
+ size_t size;
+ int extended = 0;
+
+ if (type == DIR_LOG)
+ size = entry_info->file_size;
+ else
+ size = nova_get_log_entry_size(sb, type);
+
+ tail = update->tail;
+
+ curr_p = nova_get_append_head(sb, pi, sih, tail, size,
+ MAIN_LOG, 0, &extended);
+ if (curr_p == 0)
+ return -ENOSPC;
+
+ nova_dbg_verbose("%s: inode %lu attr change entry @ 0x%llx\n",
+ __func__, sih->ino, curr_p);
+
+ entry = nova_get_block(sb, curr_p);
+ /* inode is already updated with attr */
+ memset(entry, 0, size);
+ nova_update_log_entry(sb, inode, entry, entry_info);
+ nova_inc_page_num_entries(sb, curr_p);
+ update->curr_entry = curr_p;
+ update->tail = curr_p + size;
+
+ entry_info->curr_p = curr_p;
+ return 0;
+}
+
+int nova_append_dentry(struct super_block *sb, struct nova_inode *pi,
+ struct inode *dir, struct dentry *dentry, u64 ino,
+ unsigned short de_len, struct nova_inode_update *update,
+ int link_change, u64 epoch_id)
+{
+ struct nova_inode_info *si = NOVA_I(dir);
+ struct nova_inode_info_header *sih = &si->header;
+ struct nova_log_entry_info entry_info;
+ timing_t append_time;
+ int ret;
+
+ NOVA_START_TIMING(append_dir_entry_t, append_time);
+
+ entry_info.type = DIR_LOG;
+ entry_info.update = update;
+ entry_info.data = dentry;
+ entry_info.ino = ino;
+ entry_info.link_change = link_change;
+ entry_info.file_size = de_len;
+ entry_info.epoch_id = epoch_id;
+ entry_info.trans_id = sih->trans_id;
+ entry_info.inplace = 0;
+
+ ret = nova_append_log_entry(sb, pi, dir, sih, &entry_info);
+ if (ret)
+ nova_err(sb, "%s failed\n", __func__);
+
+ dir->i_blocks = sih->i_blocks;
+
+ NOVA_END_TIMING(append_dir_entry_t, append_time);
+ return ret;
+}
+
/* Coalesce log pages to a singly linked list */
static int nova_coalesce_log_pages(struct super_block *sb,
unsigned long prev_blocknr, unsigned long first_blocknr,
diff --git a/fs/nova/log.h b/fs/nova/log.h
index 6b4a085..305e69b 100644
--- a/fs/nova/log.h
+++ b/fs/nova/log.h
@@ -364,6 +364,10 @@ static inline int is_dir_init_entry(struct super_block *sb,
}

+int nova_append_dentry(struct super_block *sb, struct nova_inode *pi,
+ struct inode *dir, struct dentry *dentry, u64 ino,
+ unsigned short de_len, struct nova_inode_update *update,
+ int link_change, u64 epoch_id);
int nova_allocate_inode_log_pages(struct super_block *sb,
struct nova_inode_info_header *sih, unsigned long num_pages,
u64 *new_block, int cpuid, enum nova_alloc_direction from_tail);
--
2.7.4