commit 1e994f0f8f00a6f4350dae185d321ff8b5d29dc4 Author: Tom Marshall Date: Tue Dec 12 00:32:06 2017 +0100 Initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..b302c43 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +.obj +gzextfs diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..b076b43 --- /dev/null +++ b/LICENSE @@ -0,0 +1,824 @@ + GNU GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1989, 1991 Free Software Foundation, Inc. + 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. By contrast, the GNU General Public +License is intended to guarantee your freedom to share and change free +software--to make sure the software is free for all its users. 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See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +Also add information on how to contact you by electronic and paper mail. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the library, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the + library `Frob' (a library for tweaking knobs) written by James Random Hacker. + + , 1 April 1990 + Ty Coon, President of Vice + +That's all there is to it! diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..b00ecac --- /dev/null +++ b/Makefile @@ -0,0 +1,84 @@ +# Makefile + +### Compatibility checks + +LIBEXT2FS_INCLUDE_ROOT := /usr/include/ext2fs + +test_file := $(LIBEXT2FS_INCLUDE_ROOT)/ext2fs.h +test_result := $(shell grep ext2fs_dirent_name_len $(test_file) | wc -l) +ifneq ($(test_result),0) +LIBEXT2_CFLAGS += -DHAVE_EXT2FS_DIRENT_NAME_LEN +endif + +test_file := $(LIBEXT2FS_INCLUDE_ROOT)/ext2_io.h +test_result := $(shell grep cache_readahead $(test_file) | wc -l) +ifneq ($(test_result),0) +LIBEXT2_CFLAGS += -DHAVE_EXT2FS_CACHE_READAHEAD +endif + +test_file := $(LIBEXT2FS_INCLUDE_ROOT)/ext2_io.h +test_result := $(shell grep zeroout $(test_file) | wc -l) +ifneq ($(test_result),0) +LIBEXT2_CFLAGS += -DHAVE_EXT2FS_ZEROOUT +endif + +### Tools and flags + +CC := gcc +CFLAGS := -g -Wall $(LIBEXT2_CFLAGS) + +CXX := g++ +CXXFLAGS := $(CFLAGS) + +LD := g++ +LDFLAGS := -g + +STATIC_LIBS := +SHARED_LIBS := -lfuse -lext2fs -lz + +DESTDIR ?= /usr/local +BINDIR ?= $(DESTDIR)/bin + +### Rules + +MODULE := gzextfs + +SRC_FILES := \ + gzextio.cxx \ + gzextfs.cxx + +all: $(MODULE) +.PHONY: all + +obj_dir := .obj + +c_sources := $(filter %.c,$(SRC_FILES)) +c_objects := $(addprefix $(obj_dir)/,$(c_sources:.c=.o)) + +cxx_sources := $(filter %.cxx,$(SRC_FILES)) +cxx_objects := $(addprefix $(obj_dir)/,$(cxx_sources:.cxx=.o)) + +module_objects := $(c_objects) $(cxx_objects) + +ifeq (,$(filter clean,$(MAKECMDGOALS))) +-include $(obj_dir)/*.d +endif + +$(MODULE): $(module_objects) + $(LD) $(LDFLAGS) -o $@ $^ $(STATIC_LIBS) $(SHARED_LIBS) + +$(obj_dir)/%.o: %.c + @mkdir -p $(@D) + $(CC) $(CFLAGS) -MD -MP -MF $(@D)/$(@F:.o=.d) -c -o $@ $< + +$(obj_dir)/%.o: %.cxx + @mkdir -p $(@D) + $(CXX) $(CXXFLAGS) -MD -MP -MF $(@D)/$(@F:.o=.d) -c -o $@ $< + +.PHONY: clean +clean: + rm -rf $(obj_dir) $(MODULE) + +.PHONY: install +install: $(MODULE) + install -m 0755 $(MODULE) $(BINDIR) diff --git a/README b/README new file mode 100644 index 0000000..aa8441f --- /dev/null +++ b/README @@ -0,0 +1,18 @@ +This is the gzextfs package. It is a FUSE filesystem implementation +which is able to mount a gzip compressed ext2/3/4 image. + +Installation instructions: + + make + make install + +Usage instructions: + + gzextfs --filename=image.gz /mnt + +The official source code repository for gzextfs can be found at: + + https://github.com/tdm/gzextfs + +Copyright (C) Tom Marshall +Licensed under the GNU Public License version 2. diff --git a/gzextdef.h b/gzextdef.h new file mode 100644 index 0000000..5f809c5 --- /dev/null +++ b/gzextdef.h @@ -0,0 +1,8 @@ +#ifndef GZEXTDEF_H +#define GZEXTDEF_H + +#define _FILE_OFFSET_BITS 64 + +#define FUSE_USE_VERSION 26 + +#endif diff --git a/gzextfs.cxx b/gzextfs.cxx new file mode 100644 index 0000000..1590752 --- /dev/null +++ b/gzextfs.cxx @@ -0,0 +1,521 @@ +/* gsextfs.cxx */ + +#include "gzextdef.h" + +#include +#include +#include + +#include +#include + +#include + +extern "C" { +#include +#include +} +#ifndef HAVE_EXT2FS_DIRENT_NAME_LEN +static inline int +ext2fs_dirent_name_len(const struct ext2_dir_entry *entry) +{ + return entry->name_len & 0xff; +} +#endif + +#include "gzextio.h" + +#include +#include +#include + +using namespace std; + +typedef list stringlist; + +typedef map pathcache; +typedef map inodecache; +typedef map dircache; + +struct file_state { + pthread_mutex_t lock; +}; +typedef map filemap; + +static struct options { + const char* filename; + int show_help; +} options; + +struct gzfs_priv { + char* filename; + ext2_filsys fs; + + pthread_mutex_t path_lock; + pathcache path_cache; + pthread_mutex_t inode_lock; + inodecache inode_cache; + pthread_mutex_t dir_lock; + dircache dir_cache; + + pthread_mutex_t file_lock; + filemap file_table; +}; +#define GZFS_PRIV(p) ((struct gzfs_priv*)(p->private_data)) + +/*** ext2 helpers ***/ + +static bool +lookup_path(struct gzfs_priv* priv, const char* pathname, ext2_ino_t& inum) +{ + const char* p; + const char* q; + ext2_ino_t dir; + ext2_ino_t subdir; + + if (!*pathname) { + inum = EXT2_ROOT_INO; + return true; + } + + pthread_mutex_lock(&priv->path_lock); + + pathcache::iterator itr = priv->path_cache.find(pathname); + if (itr != priv->path_cache.end()) { + inum = itr->second; + pthread_mutex_unlock(&priv->path_lock); + return true; + } + + dir = EXT2_ROOT_INO; + + p = pathname; + q = strchr(p, '/'); + while (q) { + if (ext2fs_lookup(priv->fs, dir, p, q - p, NULL, &subdir) != 0) { + pthread_mutex_unlock(&priv->path_lock); + return false; + } + dir = subdir; + p = q + 1; + q = strchr(p, '/'); + } + + if (ext2fs_lookup(priv->fs, dir, p, strlen(p), NULL, &inum) != 0) { + pthread_mutex_unlock(&priv->path_lock); + return false; + } + + priv->path_cache[pathname] = inum; + + pthread_mutex_unlock(&priv->path_lock); + + return true; +} + +static bool +lookup_inode(struct gzfs_priv* priv, ext2_ino_t inum, ext2_inode& inode) +{ + pthread_mutex_lock(&priv->inode_lock); + + inodecache::iterator itr = priv->inode_cache.find(inum); + if (itr != priv->inode_cache.end()) { + inode = itr->second; + pthread_mutex_unlock(&priv->inode_lock); + return true; + } + + if (ext2fs_read_inode(priv->fs, inum, &inode) != 0) { + pthread_mutex_unlock(&priv->inode_lock); + return false; + } + + priv->inode_cache[inum] = inode; + + pthread_mutex_unlock(&priv->inode_lock); + + return true; +} + +static int +dir_iterator(struct ext2_dir_entry* dirent, int offset, + int blocksize, char* buf, void* priv) +{ + stringlist* filenames = (stringlist*)priv; + + filenames->push_back(string(dirent->name, ext2fs_dirent_name_len(dirent))); + + return 0; +} + +static bool +lookup_dir(struct gzfs_priv* priv, ext2_ino_t inum, stringlist& filenames) +{ + pthread_mutex_lock(&priv->dir_lock); + + dircache::iterator itr = priv->dir_cache.find(inum); + if (itr != priv->dir_cache.end()) { + filenames = itr->second; + pthread_mutex_unlock(&priv->dir_lock); + return true; + } + + if (ext2fs_dir_iterate(priv->fs, inum, 0, NULL, dir_iterator, &filenames) != 0) { + pthread_mutex_unlock(&priv->dir_lock); + return false; + } + + priv->dir_cache[inum] = filenames; + + pthread_mutex_unlock(&priv->dir_lock); + + return true; +} + +/*** FUSE operations ***/ + +static int +gzfs_getattr(const char* path, struct stat* st) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + ext2_ino_t inum; + struct ext2_inode inode; + + if (*path != '/') { + return -1; + } + + if (!lookup_path(priv, path + 1, inum)) { + return -1; + } + + if (!lookup_inode(priv, inum, inode)) { + return -1; + } + + st->st_ino = inum; + st->st_mode = inode.i_mode; + st->st_nlink = inode.i_links_count; + st->st_uid = inode.i_uid; + st->st_gid = inode.i_gid; + st->st_size = inode.i_size; + st->st_blksize = 4096 /* XXX */; + st->st_blocks = inode.i_blocks; + st->st_atime = inode.i_atime; + st->st_mtime = inode.i_mtime; + st->st_ctime = inode.i_ctime; + + return 0; +} + +static int +gzfs_readlink(const char* path, char* buf, size_t size) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + ext2_ino_t inum; + struct ext2_inode inode; + + if (*path != '/') { + return -1; + } + + if (!lookup_path(priv, path+1, inum)) { + return -1; + } + + if (!lookup_inode(priv, inum, inode)) { + return -1; + } + + /* XXX: The below needs tested thoroughly. */ + char linkbuf[PATH_MAX + 1]; + size_t linksize; + if (ext2fs_inode_has_valid_blocks(&inode)) { + ext2_file_t file; + unsigned int nread; + if (ext2fs_file_open(priv->fs, inum, 0, &file) != 0) { + return -1; + } + if (ext2fs_file_read(file, linkbuf, sizeof(linkbuf), &nread) != 0) { + ext2fs_file_close(file); + return -1; + } + linksize = nread; + ext2fs_file_close(file); + } + else { + memcpy(linkbuf, (const char*)inode.i_block, sizeof(inode.i_block)); + linksize = sizeof(inode.i_block); + } + + if (size > linksize) { + size = linksize; + } + memcpy(buf, linkbuf, size); + + return 0; +} + +static int +gzfs_open(const char* path, struct fuse_file_info* ffi) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + ext2_ino_t inum; + ext2_file_t file; + + if (*path != '/') { + return -1; + } + + if (!lookup_path(priv, path + 1, inum)) { + return -1; + } + + if (ext2fs_file_open(priv->fs, inum, 0, &file) != 0) { + return -1; + } + + file_state* state = new file_state; + pthread_mutex_init(&state->lock, NULL); + + pthread_mutex_lock(&priv->file_lock); + priv->file_table[file] = state; + pthread_mutex_unlock(&priv->file_lock); + + ffi->fh = (uint64_t)file; + + return 0; +} + +static int +gzfs_read(const char* path, char* buf, size_t size, off_t off, struct fuse_file_info* ffi) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + __u64 pos; + unsigned int nread; + ext2_file_t file = (ext2_file_t)ffi->fh; + + pthread_mutex_lock(&priv->file_lock); + file_state* state = priv->file_table.find(file)->second; + pthread_mutex_unlock(&priv->file_lock); + + pthread_mutex_lock(&state->lock); + + if (ext2fs_file_llseek(file, off, SEEK_SET, &pos) != 0) { + pthread_mutex_unlock(&state->lock); + return -1; + } + + if (ext2fs_file_read(file, buf, size, &nread) != 0) { + pthread_mutex_unlock(&state->lock); + return -1; + } + + pthread_mutex_unlock(&state->lock); + + return nread; +} + +static int +gzfs_statfs(const char* param1, struct statvfs* param2) +{ + return -1; +} + +static int +gzfs_flush(const char* param1, struct fuse_file_info* ffi) +{ + return 0; +} + +static int +gzfs_release(const char* param1, struct fuse_file_info* ffi) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + ext2_file_t file = (ext2_file_t)ffi->fh; + + pthread_mutex_lock(&priv->file_lock); + filemap::iterator itr = priv->file_table.find(file); + file_state* state = itr->second; + priv->file_table.erase(itr); + pthread_mutex_unlock(&priv->file_lock); + + pthread_mutex_destroy(&state->lock); + delete state; + + ext2fs_file_close(file); + + return 0; +} + +static int +gzfs_readdir(const char* path, void* buf, fuse_fill_dir_t filler, off_t off, struct fuse_file_info* ffi) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + ext2_ino_t inum; + + if (*path != '/') { + return -1; + } + + if (!lookup_path(priv, path+1, inum)) { + return -1; + } + + stringlist filenames; + if (!lookup_dir(priv, inum, filenames)) { + return -1; + } + + stringlist::iterator itr; + for (itr = filenames.begin(); itr != filenames.end(); ++itr) { + const string& name = *itr; + if (filler(buf, name.c_str(), NULL, 0) != 0) { + break; + } + } + + return 0; +} + +static void* +gzfs_init(struct fuse_conn_info *conn) +{ + errcode_t rc; + + struct gzfs_priv* priv = new gzfs_priv; + + priv->filename = strdup(options.filename); + pthread_mutex_init(&priv->path_lock, NULL); + pthread_mutex_init(&priv->inode_lock, NULL); + pthread_mutex_init(&priv->dir_lock, NULL); + pthread_mutex_init(&priv->file_lock, NULL); + + rc = ext2fs_open(priv->filename, + 0 /* flags */, + 0 /* superblock */, + 4096 /* block_size */, + const_cast(gzext_io_manager), + &priv->fs); + if (rc != 0) { + fprintf(stderr, "Failed to open ext2 filesystem on %s\n", priv->filename); + exit(1); + } + + return priv; +} + +static void +gzfs_destroy(void* param) +{ + struct gzfs_priv* priv = GZFS_PRIV(fuse_get_context()); + + ext2fs_close(priv->fs); + + delete priv; +} + +static const struct fuse_operations gzfs_oper = { + .getattr = gzfs_getattr, + .readlink = gzfs_readlink, + .getdir = NULL, + .mknod = NULL, + .mkdir = NULL, + .unlink = NULL, + .rmdir = NULL, + .symlink = NULL, + .rename = NULL, + .link = NULL, + .chmod = NULL, + .chown = NULL, + .truncate = NULL, + .utime = NULL, + .open = gzfs_open, + .read = gzfs_read, + .write = NULL, + .statfs = gzfs_statfs, + .flush = gzfs_flush, + .release = gzfs_release, + .fsync = NULL, + .setxattr = NULL, + .getxattr = NULL, + .listxattr = NULL, + .removexattr = NULL, + .opendir = NULL, + .readdir = gzfs_readdir, + .releasedir = NULL, + .fsyncdir = NULL, + .init = gzfs_init, + .destroy = gzfs_destroy, + .access = NULL, + .create = NULL, + .ftruncate = NULL, + .fgetattr = NULL, + .lock = NULL, + .utimens = NULL, + .bmap = NULL, + .flag_nullpath_ok = 0, + .flag_nopath = 0, + .flag_utime_omit_ok = 0, + .flag_reserved = 0, + .ioctl = NULL, + .poll = NULL, + .write_buf = NULL, + .read_buf = NULL, + .flock = NULL, + .fallocate = NULL, +}; + +#define OPTION(t,p) \ + { t, offsetof(struct options, p), 1 } + +static const struct fuse_opt option_spec[] = { + OPTION("--filename=%s", filename), + OPTION("-h", show_help), + OPTION("--help", show_help), + FUSE_OPT_END +}; + +static void +usage(const char* argv0) +{ + fprintf(stderr, "Usage: %s --filename= ... \n", argv0); + exit(1); +} + +int +main(int argc, char** argv) +{ + struct fuse_args args = FUSE_ARGS_INIT(argc, argv); + + if ((getuid() == 0) || (geteuid() == 0)) { + fprintf(stderr, "Refusing to run as root.\n"); + exit(1); + } + + if (fuse_opt_parse(&args, &options, option_spec, NULL) == -1) { + return 1; + } + + if (options.show_help) { + usage(argv[0]); + } + + if (!options.filename) { + usage(argv[0]); + } + char* real_filename = NULL; + if (options.filename[0] == '/') { + real_filename = strdup(options.filename); + } + else { + real_filename = (char*)malloc(PATH_MAX + 1); + if (realpath(options.filename, real_filename) == NULL) { + fprintf(stderr, "Failed to resolve %s\n", options.filename); + exit(1); + } + options.filename = real_filename; + } + + return fuse_main(args.argc, args.argv, &gzfs_oper, NULL); +} diff --git a/gzextio.cxx b/gzextio.cxx new file mode 100644 index 0000000..5a5521a --- /dev/null +++ b/gzextio.cxx @@ -0,0 +1,283 @@ +/* gzextio.cxx */ + +#include "gzextdef.h" + +#include +#include +#include +#include +#include + +#include + +#include +#include +#include +#include +#include + +#include "gzextio.h" + +#include +#include +#include + +using namespace std; + +typedef map blockcache; +typedef vector blockhistory; + +/* + * Cache roughly 1gb of block data: + * 64kb * 16k = 1gb + */ +#define GZ_CACHE_BLOCKSIZE (1024*1024) +#define GZ_CACHE_SIZE (1024) + +struct gz_cache_entry { + unsigned long block; + unsigned char data[GZ_CACHE_BLOCKSIZE]; +}; + +struct gzio_priv { + uint64_t offset; + pthread_mutex_t lock; + gzFile file; + blockcache cache; + size_t index; + blockhistory history; +}; +#define GZIO_PRIV(p) ((struct gzio_priv*)(p->private_data)) + +static unsigned char* +fetch_block(struct gzio_priv* priv, unsigned long block) +{ + blockcache::iterator itr = priv->cache.find(block); + if (itr != priv->cache.end()) { + return itr->second; + } + + if (gzseek(priv->file, block * GZ_CACHE_BLOCKSIZE, SEEK_SET) == -1) { + return NULL; + } + unsigned char* data = new unsigned char[GZ_CACHE_BLOCKSIZE]; + if (gzread(priv->file, data, GZ_CACHE_BLOCKSIZE) != GZ_CACHE_BLOCKSIZE) { + delete[] data; + return NULL; + } + + if (priv->cache.size() == GZ_CACHE_SIZE) { + unsigned long evict = priv->history[priv->index]; + itr = priv->cache.find(evict); + delete[] itr->second; + priv->cache.erase(itr); + } + + priv->cache[block] = data; + priv->history[priv->index] = block; + priv->index = (priv->index + 1) % GZ_CACHE_SIZE; + + return data; +} + +static int +gzio_do_read(struct gzio_priv* priv, void* buf, uint64_t off, uint64_t len) +{ + pthread_mutex_lock(&priv->lock); + + while (len > 0) { + unsigned long block = off / GZ_CACHE_BLOCKSIZE; + unsigned char* data = fetch_block(priv, block); + if (!data) { + pthread_mutex_unlock(&priv->lock); + return -1; + } + uint64_t copyoff = off - (block * GZ_CACHE_BLOCKSIZE); + uint64_t copylen = GZ_CACHE_BLOCKSIZE - copyoff; + if (copylen > len) { + copylen = len; + } + memcpy(buf, data + copyoff, copylen); + off += copylen; + len -= copylen; + buf = (unsigned char*)buf + copylen; + } + + pthread_mutex_unlock(&priv->lock); + + return 0; +} + +static errcode_t +gzio_open(const char* name, int flags, io_channel* channel) +{ + gzFile gzf = NULL; + io_channel io = NULL; + struct gzio_priv* priv = NULL; + + gzf = gzopen(name, "rb"); + if (!gzf) { + return errno; + } + + io = new struct_io_channel; + memset(io, 0, sizeof(*io)); + io->magic = EXT2_ET_MAGIC_IO_CHANNEL; + io->manager = const_cast(gzext_io_manager); + io->name = strdup(name); + io->block_size = 1024; + io->refcount = 1; + + priv = new gzio_priv; + memset(priv, 0, sizeof(*priv)); + pthread_mutex_init(&priv->lock, NULL); + priv->file = gzf; + priv->cache = blockcache(); + priv->history = blockhistory(GZ_CACHE_SIZE); + + io->private_data = priv; + + *channel = io; + + return 0; +} + +static errcode_t +gzio_close(io_channel channel) +{ + struct gzio_priv* priv = GZIO_PRIV(channel); + + channel->private_data = NULL; + gzclose(priv->file); + pthread_mutex_destroy(&priv->lock); + delete priv; + + return 0; +} + +static errcode_t +gzio_set_blksize(io_channel channel, int blksize) +{ + channel->block_size = blksize; + + return 0; +} + +static errcode_t +gzio_read_blk(io_channel channel, unsigned long block, int count, void* data) +{ + struct gzio_priv* priv = GZIO_PRIV(channel); + uint64_t off; + uint64_t len; + + off = priv->offset + block * channel->block_size; + len = (count < 0) ? -count : count * channel->block_size; + + return gzio_do_read(priv, data, off, len); +} + +static errcode_t +gzio_write_blk(io_channel channel, unsigned long block, int count, const void* data) +{ + return EXT2_ET_UNIMPLEMENTED; +} + +static errcode_t +gzio_flush(io_channel channel) +{ + return 0; +} + +static errcode_t +gzio_write_byte(io_channel channel, unsigned long offset, int count, const void* data) +{ + return EXT2_ET_UNIMPLEMENTED; +} + +static errcode_t +gzio_set_option(io_channel channel, const char *option, const char *arg) +{ + struct gzio_priv* priv = GZIO_PRIV(channel); + + if (!strcmp(option, "offset")) { + if (!arg) { + return EXT2_ET_INVALID_ARGUMENT; + } + priv->offset = atoi(arg); + return 0; + } + + return EXT2_ET_INVALID_ARGUMENT; +} + +static errcode_t +gzio_get_stats(io_channel channel, io_stats *io_stats) +{ + return EXT2_ET_UNIMPLEMENTED; +} + +static errcode_t +gzio_read_blk64(io_channel channel, unsigned long long block, int count, void *data) +{ + struct gzio_priv* priv = GZIO_PRIV(channel); + uint64_t off; + uint64_t len; + + off = priv->offset + block * channel->block_size; + len = (count < 0) ? -count : count * channel->block_size; + + return gzio_do_read(priv, data, off, len); +} + +static errcode_t +gzio_write_blk64(io_channel channel, unsigned long long block, int count, const void *data) +{ + return EXT2_ET_UNIMPLEMENTED; +} + +static errcode_t +gzio_discard(io_channel channel, unsigned long long block, unsigned long long count) +{ + return EXT2_ET_UNIMPLEMENTED; +} + +#ifdef HAVE_EXT2FS_CACHE_READAHEAD +static errcode_t +gzio_cache_readahead(io_channel channel, unsigned long long block, unsigned long long count) +{ + return 0; +} +#endif + +#ifdef HAVE_EXT2FS_ZEROOUT +static errcode_t +gzio_zeroout(io_channel channel, unsigned long long block, unsigned long long count) +{ + return EXT2_ET_UNIMPLEMENTED; +} +#endif + +static const struct struct_io_manager struct_gzext_manager = { + .magic = EXT2_ET_MAGIC_IO_MANAGER, + .name = "gzip I/O Manager", + .open = gzio_open, + .close = gzio_close, + .set_blksize = gzio_set_blksize, + .read_blk = gzio_read_blk, + .write_blk = gzio_write_blk, + .flush = gzio_flush, + .write_byte = gzio_write_byte, + .set_option = gzio_set_option, + .get_stats = gzio_get_stats, + .read_blk64 = gzio_read_blk64, + .write_blk64 = gzio_write_blk64, + .discard = gzio_discard, +#ifdef HAVE_EXT2FS_CACHE_READAHEAD + .cache_readahead = gzio_cache_readahead, +#endif +#ifdef HAVE_EXT2FS_ZEROOUT + .zeroout = gzio_zeroout, +#endif +}; + +const struct_io_manager* gzext_io_manager = &struct_gzext_manager; diff --git a/gzextio.h b/gzextio.h new file mode 100644 index 0000000..87e68f6 --- /dev/null +++ b/gzextio.h @@ -0,0 +1,14 @@ +#ifndef GZEXTIO_H +#define GZEXTIO_H + +#ifdef __cplusplus +extern "C" { +#endif + +extern const struct_io_manager* gzext_io_manager; + +#ifdef __cplusplus +} +#endif + +#endif