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Diffstat (limited to 'api/src/glfs.h')
| -rw-r--r-- | api/src/glfs.h | 581 |
1 files changed, 581 insertions, 0 deletions
diff --git a/api/src/glfs.h b/api/src/glfs.h new file mode 100644 index 000000000..18fda496e --- /dev/null +++ b/api/src/glfs.h @@ -0,0 +1,581 @@ +/* + Copyright (c) 2012 Red Hat, Inc. <http://www.redhat.com> + This file is part of GlusterFS. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ + + +#ifndef _GLFS_H +#define _GLFS_H + +/* + Enforce the following flags as libgfapi is built + with them, and we want programs linking against them to also + be built with these flags. This is necessary as it affects + some of the structures defined in libc headers (like struct stat) + and those definitions need to be consistently compiled in + both the library and the application. +*/ + +#ifndef _FILE_OFFSET_BITS +#define _FILE_OFFSET_BITS 64 +#endif + +#ifndef __USE_FILE_OFFSET64 +#define __USE_FILE_OFFSET64 +#endif + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <sys/uio.h> +#include <unistd.h> +#include <sys/cdefs.h> +#include <dirent.h> +#include <sys/statvfs.h> + +__BEGIN_DECLS + +/* The filesystem object. One object per 'virtual mount' */ +struct glfs; +typedef struct glfs glfs_t; + + +/* + SYNOPSIS + + glfs_new: Create a new 'virtual mount' object. + + DESCRIPTION + + This is most likely the very first function you will use. This function + will create a new glfs_t (virtual mount) object in memory. + + On this newly created glfs_t, you need to be either set a volfile path + (glfs_set_volfile) or a volfile server (glfs_set_volfile_server). + + The glfs_t object needs to be initialized with glfs_init() before you + can start issuing file operations on it. + + PARAMETERS + + @volname: Name of the volume. This identifies the server-side volume and + the fetched volfile (equivalent of --volfile-id command line + parameter to glusterfsd). When used with glfs_set_volfile() the + @volname has no effect (except for appearing in log messages). + + RETURN VALUES + + NULL : Out of memory condition. + Others : Pointer to the newly created glfs_t virtual mount object. + +*/ + +glfs_t *glfs_new (const char *volname); + + +/* + SYNOPSIS + + glfs_set_volfile: Specify the path to the volume specification file. + + DESCRIPTION + + If you are using a static volume specification file (without dynamic + volume management abilities from the CLI), then specify the path to + the volume specification file. + + This is incompatible with glfs_set_volfile_server(). + + PARAMETERS + + @fs: The 'virtual mount' object to be configured with the volume + specification file. + + @volfile: Path to the locally available volume specification file. + + RETURN VALUES + + 0 : Success. + -1 : Failure. @errno will be set with the type of failure. + +*/ + +int glfs_set_volfile (glfs_t *fs, const char *volfile); + + +/* + SYNOPSIS + + glfs_set_volfile_server: Specify the address of management server. + + DESCRIPTION + + This function specifies the address of the management server (glusterd) + to connect, and establish the volume configuration. The @volname + parameter passed to glfs_new() is the volume which will be virtually + mounted as the glfs_t object. All operations performed by the CLI at + the management server will automatically be reflected in the 'virtual + mount' object as it maintains a connection to glusterd and polls on + configuration change notifications. + + This is incompatible with glfs_set_volfile(). + + PARAMETERS + + @fs: The 'virtual mount' object to be configured with the volume + specification file. + + @transport: String specifying the transport used to connect to the + management daemon. Specifying NULL will result in the usage + of the default (tcp) transport type. Permitted values + are those what you specify as transport-type in a volume + specification file (e.g "tcp", "rdma", "unix".) + + @host: String specifying the address of where to find the management + daemon. Depending on the transport type this would either be + an FQDN (e.g: "storage01.company.com"), ASCII encoded IP + address "192.168.22.1", or a UNIX domain socket path (e.g + "/tmp/glusterd.socket".) + + @port: The TCP port number where gluster management daemon is listening. + Specifying 0 uses the default port number GF_DEFAULT_BASE_PORT. + This parameter is unused if you are using a UNIX domain socket. + + RETURN VALUES + + 0 : Success. + -1 : Failure. @errno will be set with the type of failure. + +*/ + +int glfs_set_volfile_server (glfs_t *fs, const char *transport, + const char *host, int port); + + +/* + SYNOPSIS + + glfs_set_logging: Specify logging parameters. + + DESCRIPTION + + This function specifies logging parameters for the virtual mount. + Default log file is /dev/null. + + PARAMETERS + + @fs: The 'virtual mount' object to be configured with the logging parameters. + + @logfile: The logfile to be used for logging. Will be created if it does not + already exist (provided system permissions allow). If NULL, a new + logfile will be created in default log directory associated with + the glusterfs installation. + + @loglevel: Numerical value specifying the degree of verbosity. Higher the + value, more verbose the logging. + + RETURN VALUES + + 0 : Success. + -1 : Failure. @errno will be set with the type of failure. + +*/ + +int glfs_set_logging (glfs_t *fs, const char *logfile, int loglevel); + + +/* + SYNOPSIS + + glfs_init: Initialize the 'virtual mount' + + DESCRIPTION + + This function initializes the glfs_t object. This consists of many steps: + - Spawn a poll-loop thread. + - Establish connection to management daemon and receive volume specification. + - Construct translator graph and initialize graph. + - Wait for initialization (connecting to all bricks) to complete. + + PARAMETERS + + @fs: The 'virtual mount' object to be initialized. + + RETURN VALUES + + 0 : Success. + -1 : Failure. @errno will be set with the type of failure. + +*/ + +int glfs_init (glfs_t *fs); + + +/* + SYNOPSIS + + glfs_fini: Cleanup and destroy the 'virtual mount' + + DESCRIPTION + + This function attempts to gracefully destroy glfs_t object. An attempt is + made to wait for all background processing to complete before returning. + + glfs_fini() must be called after all operations on glfs_t is finished. + + IMPORTANT + + IT IS NECESSARY TO CALL glfs_fini() ON ALL THE INITIALIZED glfs_t + OBJECTS BEFORE TERMINATING THE PROGRAM. THERE MAY BE CACHED AND + UNWRITTEN / INCOMPLETE OPERATIONS STILL IN PROGRESS EVEN THOUGH THE + API CALLS HAVE RETURNED. glfs_fini() WILL WAIT FOR BACKGROUND OPERATIONS + TO COMPLETE BEFORE RETURNING, THEREBY MAKING IT SAFE FOR THE PROGRAM TO + EXIT. + + PARAMETERS + + @fs: The 'virtual mount' object to be destroyed. + + RETURN VALUES + + 0 : Success. +*/ + +int glfs_fini (glfs_t *fs); + +/* + * FILE OPERATION + * + * What follows are filesystem operations performed on the + * 'virtual mount'. The calls here are kept as close to + * the POSIX system calls as possible. + * + * Notes: + * + * - All paths specified, even if absolute, are relative to the + * root of the virtual mount and not the system root (/). + * + */ + +/* The file descriptor object. One per open file/directory. */ + +struct glfs_fd; +typedef struct glfs_fd glfs_fd_t; + +/* + * PER THREAD IDENTITY MODIFIERS + * + * The following operations enable to set a per thread identity context + * for the glfs APIs to perform operations as. The calls here are kept as close + * to POSIX equivalents as possible. + * + * NOTES: + * + * - setgroups is a per thread setting, hence this is named as fsgroups to be + * close in naming to the fs(u/g)id APIs + * - Typical mode of operation is to set the IDs as required, with the + * supplementary groups being optionally set, make the glfs call and post the + * glfs operation set them back to eu/gid or uid/gid as appropriate to the + * caller + * - The groups once set, need to be unset by setting the size to 0 (in which + * case the list argument is a do not care) + * - Once a process for a thread of operation choses to set the IDs, all glfs + * calls made from that thread would default to the IDs set for the thread. + * As a result use these APIs with care and ensure that the set IDs are + * reverted to global process defaults as required. + * + */ +int glfs_setfsuid (uid_t fsuid); +int glfs_setfsgid (gid_t fsgid); +int glfs_setfsgroups (size_t size, const gid_t *list); + +/* + SYNOPSIS + + glfs_open: Open a file. + + DESCRIPTION + + This function opens a file on a virtual mount. + + PARAMETERS + + @fs: The 'virtual mount' object to be initialized. + + @path: Path of the file within the virtual mount. + + @flags: Open flags. See open(2). O_CREAT is not supported. + Use glfs_creat() for creating files. + + RETURN VALUES + + NULL : Failure. @errno will be set with the type of failure. + Others : Pointer to the opened glfs_fd_t. + + */ + +glfs_fd_t *glfs_open (glfs_t *fs, const char *path, int flags); + + +/* + SYNOPSIS + + glfs_creat: Create a file. + + DESCRIPTION + + This function opens a file on a virtual mount. + + PARAMETERS + + @fs: The 'virtual mount' object to be initialized. + + @path: Path of the file within the virtual mount. + + @mode: Permission of the file to be created. + + @flags: Create flags. See open(2). O_EXCL is supported. + + RETURN VALUES + + NULL : Failure. @errno will be set with the type of failure. + Others : Pointer to the opened glfs_fd_t. + + */ + +glfs_fd_t *glfs_creat (glfs_t *fs, const char *path, int flags, + mode_t mode); + +int glfs_close (glfs_fd_t *fd); + +glfs_t *glfs_from_glfd (glfs_fd_t *fd); + +int glfs_set_xlator_option (glfs_t *fs, const char *xlator, const char *key, + const char *value); + +/* + + glfs_io_cbk + + The following is the function type definition of the callback + function pointer which has to be provided by the caller to the + *_async() versions of the IO calls. + + The callback function is called on completion of the requested + IO, and the appropriate return value is returned in @ret. + + In case of an error in completing the IO, @ret will be -1 and + @errno will be set with the appropriate error. + + @ret will be same as the return value of the non _async() variant + of the particular call + + @data is the same context pointer provided by the caller at the + time of issuing the async IO call. This can be used by the + caller to differentiate different instances of the async requests + in a common callback function. +*/ + +typedef void (*glfs_io_cbk) (glfs_fd_t *fd, ssize_t ret, void *data); + +// glfs_{read,write}[_async] + +ssize_t glfs_read (glfs_fd_t *fd, void *buf, size_t count, int flags); +ssize_t glfs_write (glfs_fd_t *fd, const void *buf, size_t count, int flags); +int glfs_read_async (glfs_fd_t *fd, void *buf, size_t count, int flags, + glfs_io_cbk fn, void *data); +int glfs_write_async (glfs_fd_t *fd, const void *buf, size_t count, int flags, + glfs_io_cbk fn, void *data); + +// glfs_{read,write}v[_async] + +ssize_t glfs_readv (glfs_fd_t *fd, const struct iovec *iov, int iovcnt, + int flags); +ssize_t glfs_writev (glfs_fd_t *fd, const struct iovec *iov, int iovcnt, + int flags); +int glfs_readv_async (glfs_fd_t *fd, const struct iovec *iov, int count, + int flags, glfs_io_cbk fn, void *data); +int glfs_writev_async (glfs_fd_t *fd, const struct iovec *iov, int count, + int flags, glfs_io_cbk fn, void *data); + +// glfs_p{read,write}[_async] + +ssize_t glfs_pread (glfs_fd_t *fd, void *buf, size_t count, off_t offset, + int flags); +ssize_t glfs_pwrite (glfs_fd_t *fd, const void *buf, size_t count, + off_t offset, int flags); +int glfs_pread_async (glfs_fd_t *fd, void *buf, size_t count, off_t offset, + int flags, glfs_io_cbk fn, void *data); +int glfs_pwrite_async (glfs_fd_t *fd, const void *buf, int count, off_t offset, + int flags, glfs_io_cbk fn, void *data); + +// glfs_p{read,write}v[_async] + +ssize_t glfs_preadv (glfs_fd_t *fd, const struct iovec *iov, int iovcnt, + off_t offset, int flags); +ssize_t glfs_pwritev (glfs_fd_t *fd, const struct iovec *iov, int iovcnt, + off_t offset, int flags); +int glfs_preadv_async (glfs_fd_t *fd, const struct iovec *iov, int count, + off_t offset, int flags, glfs_io_cbk fn, void *data); +int glfs_pwritev_async (glfs_fd_t *fd, const struct iovec *iov, int count, + off_t offset, int flags, glfs_io_cbk fn, void *data); + + +off_t glfs_lseek (glfs_fd_t *fd, off_t offset, int whence); + +int glfs_truncate (glfs_t *fs, const char *path, off_t length); + +int glfs_ftruncate (glfs_fd_t *fd, off_t length); +int glfs_ftruncate_async (glfs_fd_t *fd, off_t length, glfs_io_cbk fn, + void *data); + +int glfs_lstat (glfs_t *fs, const char *path, struct stat *buf); +int glfs_stat (glfs_t *fs, const char *path, struct stat *buf); +int glfs_fstat (glfs_fd_t *fd, struct stat *buf); + +int glfs_fsync (glfs_fd_t *fd); +int glfs_fsync_async (glfs_fd_t *fd, glfs_io_cbk fn, void *data); + +int glfs_fdatasync (glfs_fd_t *fd); +int glfs_fdatasync_async (glfs_fd_t *fd, glfs_io_cbk fn, void *data); + +int glfs_access (glfs_t *fs, const char *path, int mode); + +int glfs_symlink (glfs_t *fs, const char *oldpath, const char *newpath); + +int glfs_readlink (glfs_t *fs, const char *path, char *buf, size_t bufsiz); + +int glfs_mknod (glfs_t *fs, const char *path, mode_t mode, dev_t dev); + +int glfs_mkdir (glfs_t *fs, const char *path, mode_t mode); + +int glfs_unlink (glfs_t *fs, const char *path); + +int glfs_rmdir (glfs_t *fs, const char *path); + +int glfs_rename (glfs_t *fs, const char *oldpath, const char *newpath); + +int glfs_link (glfs_t *fs, const char *oldpath, const char *newpath); + +glfs_fd_t *glfs_opendir (glfs_t *fs, const char *path); + +/* + * @glfs_readdir_r and @glfs_readdirplus_r ARE thread safe AND re-entrant, + * but the interface has ambiguity about the size of @dirent to be allocated + * before calling the APIs. 512 byte buffer (for @dirent) is sufficient for + * all known systems which are tested againt glusterfs/gfapi, but may be + * insufficient in the future. + */ + +int glfs_readdir_r (glfs_fd_t *fd, struct dirent *dirent, + struct dirent **result); + +int glfs_readdirplus_r (glfs_fd_t *fd, struct stat *stat, struct dirent *dirent, + struct dirent **result); + +/* + * @glfs_readdir and @glfs_readdirplus are NEITHER thread safe NOR re-entrant + * when called on the same directory handle. However they ARE thread safe + * AND re-entrant when called on different directory handles (which may be + * referring to the same directory too.) + */ + +struct dirent *glfs_readdir (glfs_fd_t *fd); + +struct dirent *glfs_readdirplus (glfs_fd_t *fd, struct stat *stat); + +long glfs_telldir (glfs_fd_t *fd); + +void glfs_seekdir (glfs_fd_t *fd, long offset); + +int glfs_closedir (glfs_fd_t *fd); + +int glfs_statvfs (glfs_t *fs, const char *path, struct statvfs *buf); + +int glfs_chmod (glfs_t *fs, const char *path, mode_t mode); + +int glfs_fchmod (glfs_fd_t *fd, mode_t mode); + +int glfs_chown (glfs_t *fs, const char *path, uid_t uid, gid_t gid); + +int glfs_lchown (glfs_t *fs, const char *path, uid_t uid, gid_t gid); + +int glfs_fchown (glfs_fd_t *fd, uid_t uid, gid_t gid); + +int glfs_utimens (glfs_t *fs, const char *path, struct timespec times[2]); + +int glfs_lutimens (glfs_t *fs, const char *path, struct timespec times[2]); + +int glfs_futimens (glfs_fd_t *fd, struct timespec times[2]); + +ssize_t glfs_getxattr (glfs_t *fs, const char *path, const char *name, + void *value, size_t size); + +ssize_t glfs_lgetxattr (glfs_t *fs, const char *path, const char *name, + void *value, size_t size); + +ssize_t glfs_fgetxattr (glfs_fd_t *fd, const char *name, + void *value, size_t size); + +ssize_t glfs_listxattr (glfs_t *fs, const char *path, void *value, size_t size); + +ssize_t glfs_llistxattr (glfs_t *fs, const char *path, void *value, + size_t size); + +ssize_t glfs_flistxattr (glfs_fd_t *fd, void *value, size_t size); + +int glfs_setxattr (glfs_t *fs, const char *path, const char *name, + const void *value, size_t size, int flags); + +int glfs_lsetxattr (glfs_t *fs, const char *path, const char *name, + const void *value, size_t size, int flags); + +int glfs_fsetxattr (glfs_fd_t *fd, const char *name, + const void *value, size_t size, int flags); + +int glfs_removexattr (glfs_t *fs, const char *path, const char *name); + +int glfs_lremovexattr (glfs_t *fs, const char *path, const char *name); + +int glfs_fremovexattr (glfs_fd_t *fd, const char *name); + +int glfs_fallocate(glfs_fd_t *fd, int keep_size, off_t offset, size_t len); + +int glfs_discard(glfs_fd_t *fd, off_t offset, size_t len); + + +int glfs_discard_async (glfs_fd_t *fd, off_t length, size_t lent, + glfs_io_cbk fn, void *data); + +int glfs_zerofill(glfs_fd_t *fd, off_t offset, size_t len); + +int glfs_zerofill_async (glfs_fd_t *fd, off_t length, size_t len, + glfs_io_cbk fn, void *data); + +char *glfs_getcwd (glfs_t *fs, char *buf, size_t size); + +int glfs_chdir (glfs_t *fs, const char *path); + +int glfs_fchdir (glfs_fd_t *fd); + +char *glfs_realpath (glfs_t *fs, const char *path, char *resolved_path); + +/* + * @cmd and @flock are as specified in man fcntl(2). + */ +int glfs_posix_lock (glfs_fd_t *fd, int cmd, struct flock *flock); + +glfs_fd_t *glfs_dup (glfs_fd_t *fd); + +__END_DECLS + +#endif /* !_GLFS_H */ |