destroy void (*destroy) (void *userdata); 清理init缓存的文件系统信息。 lookup void (*lookup) (fuse_req_t req, fuse_ino_t parent, const char *name); 根据parent inode id和name从denty缓存中找到对应的denty结构； 如果dentry缓存中不存在对应的inode，则从mds根据parent 根据找到的denty结构，获取inodeid，设置 fuse_entry_param，返回给fuse write void (*write) (fuse_req_t req, fuse_ino_t ino, const char *buf, size_t size, off_t off, struct fuse_file_info *fi); 首先根据inode id 从缓存中查找到对应inode结构； 如果ino 构而定；inode修改需要持久化到底层并修改本地cache；© XXX Page 6 of 11 read void (*read) (fuse_req_t req, fuse_ino_t ino, size_t size, off_t off, struct fuse_file_info *fi); 首先根据inode id 从缓存中查找到对应inode结构； 如果inode缓存中不存在对

*inode, uint64_t offset, uint64_t length, const char* buf bool di); int Read(Inode *inode, uint64_t offset, uint64_t length, char* buf); int ReleaseCache(uint64_t inodeId); FsSync(); uint64_t GetBlockSize() {return blockSize_;} uint64_t GetChunkSize() {return chunkSize_;} CURVEFS_ERROR AllocS3ChunkId(uint32_t fsId); CURVEFS_ERROR GetInode(uint64_t inodeId, Inode *out); *out); private: S3Client *client_; uint64_t blockSize_; uint64_t chunkSize_; std::string metaServerEps_; std::string allocateServerEps_; Thread bgFlushThread_; std::atomic toStop_;

int flags, mode_t mode); int creat(const char *pathname, mode_t mode); int openat(int dirfd, const char *pathname, int flags); int openat(int dirfd, const char *pathname, int flags, mode_t mode); int openat2(int openat2(int dirfd, const char *pathname, const struct open_how *how, size_t size); open系统调用会打开pathname指定的文件（如果不存在，如果携带O_CREAT flag则会创建），返回一个文件描述符fd（该fd是进程打开文件描述符表的index），在后续系统调用（read(2)、write(2)、lseek(2)、fcntl(2) 用于生产临时的无名的普通文件，pathname指定一个目录。 O_TMPFILE libfuse open void(* fuse_lowlevel_ops::open)(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)© XXX Page 6 of 23 Open a file Open flags are available in

of 24 typedef uint64_t InodeId; enum FileType { TYPE_DIRECTORY = 0, TYPE_FILE, TYPE_SYM_LINK, }; class VolumeSpaceItem { uint64_t volumeOffset; // uint64_t length; // bool used; InodeId inode; uint64_t fsId; // uint32_t btime; /* birth / create time */ uint32_t ctime; /* status change time */ uint32_t mtime; /* modify time */ uint32_t atime; /* access time */ uint32_t uid; /* user id * uint32_t gid; /* group id */ uint32_t mode; /* file mode */ int nlink; /* ref count for hard link */ int64_t size; FileType

功能协商 init()函数实现© XXX Page 9 of 33 // libfuse lib/fuse_lowlevel.c static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) { struct fuse_init_in *arg = (struct fuse_init_in *) inarg; struct version and other filesystem parameters. struct fuse_init_in { uint32_t major; uint32_t minor; uint32_t max_readahead; uint32_t flags; }; // libfuse include/fuse.h /**© XXX Page 10 of 33 * Initialize STICKY # chmod o+t DIR # chmod 1777 DIR nbs@pubbeta1-nostest2:/tmp$ ls -l | grep stmp drwxrwxrwx 2 nbs netease 4096 Jul 29 11:02 stmp nbs@pubbeta1-nostest2:/tmp$ chmod o+t stmp nbs@pub

Write(std::string name, const char* buf, uint64_t length); int Read(std::string name, char* buf, uint64_t offset, uint64_t length); int CreateDir(); uint64_t GetCachedSize(); std::string GetCacheDir(); addCache(std::string name); /** * @brief tell whether the cache disk is full or not. */ int64_t CacheDiskUsedRatio(); bool IsDiskCacheFull(); bool IsDiskCacheSafe(); /**© XXX Page 5 of isRunning_; curve::common::InterruptibleSleeper sleeper_; uint32_t trimCheckInterval_; int64_t fullRatio_; int64_t safeRatio_; std::string cacheDir_; std::shared_ptr

快照目标卷名 snapshotName string 快照名 seqNum uint64_t 快照版本号 chunkSize uint32_t chunk的size segmentSize uint64_t segment的size fileLength uint64_t 卷的大小 time uint64_t 快照创建时间 status enum 快照的创建状态 Etcd中的快照元数据:快照的元数据和数据组织 ChunkFile。CHUNKSERVER端快照实现-SNAPFILE 字段 类型 说明 version uint8_t 文件格式协议 版本号 demaged bool 损坏标记 sn uint64_t 快照版本号 bits uint32_t 位图的位数 bitmap char[] 位图 crc uint32_t 上述字段的crc 校验码 padding / 填0，以补足 4KBCHUNKSERVER端快照实现-写时复制原理 version uint8_t 文件格式协议版本号 sn uint64_t chunk文件的版本号 correntSn uint64_t chunk的修正版本号 locationSi ze size_t 可缺省，当前为CloneChunk时表示 location占用的字节数 location char[] 可缺省，当前为CloneChunk时表示 克隆源字段 bits uint32_t 可缺省，当前为CloneChunk时表示

int write(Inode *inode, uint64_t offset, uint64_t length, const char* buf); int read(Inode *inode, uint64_t offset, uint64_t length, char* buf); private: S3Client* S3Client* client_; uint64_t blockSize_; uint64_t chunkSize_; }; //s3 class S3Client { public: S3Client() {} virtual ~S3Client() {} virtual void Init(curve::common::S3AdapterOption char* buf, uint64_t length) = 0; virtual int Append(std::string name, const char* buf, uint64_t length) = 0; virtual int Download(std::string name, char* buf, uint64_t offset, uint64_t length) = 0;

●增加pfs_pwritev和pfs_preadv接口 ●ssize_t pfs_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset); ●ssize_t pfs_pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset); ●IO vector的接口主要 PFS+SPDK 的DMA支持 ●ssize_t pfs_writev_dma(int fd, const struct iovec *iov, int iovcnt, off_t offset) ●ssize_t pfs_preadv_dma(int fd, const struct iovec *iov, int iovcnt, off_t offset); ●直接DMA读写，要求的内存必须是DPDK的hugetlb内存 page2+4096）， [page3, page3+512)10/17/22 14 IOPortal实现读对齐支持 ●ssize_t IOPortal::pappend_from_dev_descriptor(int fd, off_t offset, size_t max_count) ●这个函数的实现是按PRP的规定来做的 ●IOPortal就是IOBuf，是BRPC存放数据的类

并设计解决上述遗留问题。 当前删除接口代码如下：© XXX Page 3 of 15 CURVEFS_ERROR FuseClient::RemoveNode(fuse_req_t req, fuse_ino_t parent, const char *name) { Dentry dentry; CURVEFS_ERROR ret = dentryManager_->GetDentry(parent number * @param nlookup the number of lookups to forget */ void (*forget) (fuse_req_t req, fuse_ino_t ino, uint64_t nlookup); /** * Remove a file * * If the file's inode's lookup count is non-zero inode number of the parent directory * @param name to remove */ void (*unlink) (fuse_req_t req, fuse_ino_t parent, const char *name); /** * Remove a directory * * If the directory's inode's lookup