From: Andiry Xu <jix024@xxxxxxxxxxx> NOVA adds or removes a directory/file by appending a dentry to the parent directory's log. Dentry contains filename and inode number. A positive inode number indicates a create(valid) dentry, and a dentry with inode number zero is a remove dentry. NOVA can also inplace update a create dentry to invalidate it. Signed-off-by: Andiry Xu <jix024@xxxxxxxxxxx> --- fs/nova/dir.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nova/nova.h | 4 ++ 2 files changed, 144 insertions(+) diff --git a/fs/nova/dir.c b/fs/nova/dir.c index 35a66f9..47ee9ad 100644 --- a/fs/nova/dir.c +++ b/fs/nova/dir.c @@ -222,6 +222,146 @@ int nova_append_dir_init_entries(struct super_block *sb, return 0; } +/* adds a directory entry pointing to the inode. assumes the inode has + * already been logged for consistency + */ +int nova_add_dentry(struct dentry *dentry, u64 ino, int inc_link, + struct nova_inode_update *update, u64 epoch_id) +{ + struct inode *dir = dentry->d_parent->d_inode; + struct super_block *sb = dir->i_sb; + struct nova_inode_info *si = NOVA_I(dir); + struct nova_inode_info_header *sih = &si->header; + struct nova_inode *pidir; + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + struct nova_dentry *direntry; + unsigned short loglen; + int ret; + u64 curr_entry; + timing_t add_dentry_time; + + nova_dbg_verbose("%s: dir %lu new inode %llu\n", + __func__, dir->i_ino, ino); + nova_dbg_verbose("%s: %s %d\n", __func__, name, namelen); + NOVA_START_TIMING(add_dentry_t, add_dentry_time); + if (namelen == 0) + return -EINVAL; + + pidir = nova_get_inode(sb, dir); + + /* + * XXX shouldn't update any times until successful + * completion of syscall, but too many callers depend + * on this. + */ + dir->i_mtime = dir->i_ctime = current_time(dir); + + loglen = NOVA_DIR_LOG_REC_LEN(namelen); + ret = nova_append_dentry(sb, pidir, dir, dentry, + ino, loglen, update, + inc_link, epoch_id); + + if (ret) { + nova_dbg("%s: append dir entry failure\n", __func__); + return ret; + } + + curr_entry = update->curr_entry; + direntry = (struct nova_dentry *)nova_get_block(sb, curr_entry); + sih->last_dentry = curr_entry; + ret = nova_insert_dir_radix_tree(sb, sih, name, namelen, direntry); + + sih->trans_id++; + NOVA_END_TIMING(add_dentry_t, add_dentry_time); + return ret; +} + +static int nova_can_inplace_update_dentry(struct super_block *sb, + struct nova_dentry *dentry, u64 epoch_id) +{ + if (dentry && dentry->epoch_id == epoch_id) + return 1; + + return 0; +} + +/* removes a directory entry pointing to the inode. assumes the inode has + * already been logged for consistency + */ +int nova_remove_dentry(struct dentry *dentry, int dec_link, + struct nova_inode_update *update, u64 epoch_id) +{ + struct inode *dir = dentry->d_parent->d_inode; + struct super_block *sb = dir->i_sb; + struct nova_sb_info *sbi = NOVA_SB(sb); + struct nova_inode_info *si = NOVA_I(dir); + struct nova_inode_info_header *sih = &si->header; + struct nova_inode *pidir; + struct qstr *entry = &dentry->d_name; + struct nova_dentry *old_dentry = NULL; + unsigned short loglen; + int ret; + u64 curr_entry; + timing_t remove_dentry_time; + + NOVA_START_TIMING(remove_dentry_t, remove_dentry_time); + + update->create_dentry = NULL; + update->delete_dentry = NULL; + + if (!dentry->d_name.len) { + ret = -EINVAL; + goto out; + } + + ret = nova_remove_dir_radix_tree(sb, sih, entry->name, entry->len, 0, + &old_dentry); + + if (ret) + goto out; + + pidir = nova_get_inode(sb, dir); + + dir->i_mtime = dir->i_ctime = current_time(dir); + + if (nova_can_inplace_update_dentry(sb, old_dentry, epoch_id)) { + nova_inplace_update_dentry(sb, dir, old_dentry, + dec_link, epoch_id); + curr_entry = nova_get_addr_off(sbi, old_dentry); + + sih->last_dentry = curr_entry; + /* Leave create/delete_dentry to NULL + * Do not change tail if used as input + */ + if (update->tail == 0) { + update->tail = sih->log_tail; + } + sih->trans_id++; + goto out; + } + + loglen = NOVA_DIR_LOG_REC_LEN(entry->len); + ret = nova_append_dentry(sb, pidir, dir, dentry, + 0, loglen, update, + dec_link, epoch_id); + + if (ret) { + nova_dbg("%s: append dir entry failure\n", __func__); + goto out; + } + + update->create_dentry = old_dentry; + curr_entry = update->curr_entry; + update->delete_dentry = (struct nova_dentry *)nova_get_block(sb, + curr_entry); + sih->last_dentry = curr_entry; + sih->trans_id++; +out: + NOVA_END_TIMING(remove_dentry_t, remove_dentry_time); + return ret; +} + static u64 nova_find_next_dentry_addr(struct super_block *sb, struct nova_inode_info_header *sih, u64 pos) { diff --git a/fs/nova/nova.h b/fs/nova/nova.h index ed269fe..3a51dae 100644 --- a/fs/nova/nova.h +++ b/fs/nova/nova.h @@ -461,6 +461,10 @@ struct nova_dentry *nova_find_dentry(struct super_block *sb, 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); +int nova_add_dentry(struct dentry *dentry, u64 ino, int inc_link, + struct nova_inode_update *update, u64 epoch_id); +int nova_remove_dentry(struct dentry *dentry, int dec_link, + struct nova_inode_update *update, u64 epoch_id); /* rebuild.c */ int nova_rebuild_inode(struct super_block *sb, struct nova_inode_info *si, -- 2.7.4