pax_global_header00006660000000000000000000000064112051522430014505gustar00rootroot0000000000000052 comment=7bdeaffcb57283afaa4a4bb6af7f2d43ede4468c chunkfs-0.4/000075500000000000000000000000001120515224300130075ustar00rootroot00000000000000chunkfs-0.4/COPYING000064400000000000000000000431031120515224300140430ustar00rootroot00000000000000 GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Lesser General Public License instead.) You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it. For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights. We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software. Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations. Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all. The precise terms and conditions for copying, distribution and modification follow. GNU GENERAL PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 0. This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term "modification".) Each licensee is addressed as "you". Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does. 1. You may copy and distribute verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of this License along with the Program. You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee. 2. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you also meet all of these conditions: a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License. c) If the modified program normally reads commands interactively when run, you must cause it, when started running for such interactive use in the most ordinary way, to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty (or else, saying that you provide a warranty) and that users may redistribute the program under these conditions, and telling the user how to view a copy of this License. (Exception: if the Program itself is interactive but does not normally print such an announcement, your work based on the Program is not required to print an announcement.) These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it. Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program. In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License. 3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following: a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.) The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code. 4. You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance. 5. You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it. 6. Each time you redistribute the Program (or any work based on the Program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the Program subject to these terms and conditions. You may not impose any further restrictions on the recipients' exercise of the rights granted herein. You are not responsible for enforcing compliance by third parties to this License. 7. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances. It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License. 8. If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. 9. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation. 10. If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally. NO WARRANTY 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. Copyright (C) This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Also add information on how to contact you by electronic and paper mail. If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. , 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. chunkfs-0.4/INSTALL000064400000000000000000000002471120515224300140430ustar00rootroot00000000000000 You need to have libfuse >= 2.5 installed, plus perl for the build process, at least if you want to have a man page. Then, a simple make && make install should do. chunkfs-0.4/Makefile000064400000000000000000000013371120515224300144530ustar00rootroot00000000000000 PREFIX?=/usr/local VERSION=0.4 CFLAGS=-std=c99 -O2 -Wall LDFLAGS=-lfuse all: chunkfs unchunkfs chunkfs.1.gz install: install chunkfs ${DESTDIR}${PREFIX}/bin/ install unchunkfs ${DESTDIR}${PREFIX}/bin/ install -d ${DESTDIR}${PREFIX}/share/doc/chunkfs/examples/ install writeoverlay.sh ${DESTDIR}${PREFIX}/share/doc/chunkfs/examples/ install -m 644 chunkfs.1.gz ${DESTDIR}${PREFIX}/share/man/man1/ ln -s chunkfs.1.gz ${DESTDIR}${PREFIX}/share/man/man1/unchunkfs.1.gz clean: -rm chunkfs.o unchunkfs.o utils.o chunkfs unchunkfs chunkfs.1.gz chunkfs: chunkfs.o utils.o unchunkfs: unchunkfs.o utils.o chunkfs.1.gz: manpage.pod pod2man -c '' -n CHUNKFS -r 'ChunkFS ${VERSION}' -s 1 $< | gzip > $@ .PHONY: all install clean chunkfs-0.4/chunkfs.c000064400000000000000000000124111120515224300146130ustar00rootroot00000000000000/* * ChunkFS - mount arbitrary files via FUSE as a tree of chunk files * Copyright (C) 2007 Florian Zumbiehl * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #define _FILE_OFFSET_BITS 64 #define _XOPEN_SOURCE 500 #define FUSE_USE_VERSION 25 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "utils.h" struct chunk_stat { int level; mode_t mode; off_t chunk,offset,size; }; static int image_fd; static off_t chunk_size,image_size,image_chunks; #define cons_hexdig(a,b,c) { \ uint64_t t; \ if((c)>='0'&&(c)<='9'){ \ t=(c)-'0'; \ }else if((c)>='a'&&(c)<='f'){ \ t=(c)-'a'+10; \ }else{ \ return -ENOENT; \ } \ a|=t<<(b); \ } static int resolve_path(const char *path,struct chunk_stat *st){ size_t l; uint64_t r; l=strlen(path); r=0; if(l<3||l>8*3||l%3){ if(strcmp(path,"/"))return -ENOENT; }else{ for(int x=0;x=(uint64_t)image_chunks)return -ENOENT; } st->level=l/3; st->chunk=r; st->offset=st->chunk*chunk_size; if(st->level<8){ st->mode=S_IFDIR; }else{ st->mode=S_IFREG; st->size=min(image_size-st->offset,chunk_size); } return 0; } static int chunkfs_getattr(const char *path,struct stat *buf){ int r; struct chunk_stat st; if((r=resolve_path(path,&st))<0)return r; if(fstat(image_fd,buf)<0)return -errno; buf->st_mode=(buf->st_mode&~(S_IFMT|S_IXUSR|S_IXGRP|S_IXOTH))|(st.mode&S_IFMT); if(S_ISDIR(st.mode)){ buf->st_mode=buf->st_mode |((buf->st_mode&S_IRUSR)?S_IXUSR:0) |((buf->st_mode&S_IRGRP)?S_IXGRP:0) |((buf->st_mode&S_IROTH)?S_IXOTH:0); buf->st_nlink=256+2; buf->st_size=0; }else{ buf->st_nlink=1; buf->st_size=st.size; } buf->st_blocks=0; return 0; } static int chunkfs_readdir(const char *path,void *buf,fuse_fill_dir_t filler,off_t offset,struct fuse_file_info *fi){ int r; struct chunk_stat st; uint64_t chunks_per_entry; if((r=resolve_path(path,&st))<0)return r; if(!S_ISDIR(st.mode))return -ENOTDIR; chunks_per_entry=1ULL<<((8-1-st.level)*8); filler(buf,".",NULL,0); filler(buf,"..",NULL,0); for(uint64_t x=0;x<256&&(uint64_t)st.chunk+x*chunks_per_entry<(uint64_t)image_chunks;x++){ char nbuf[3]; sprintf(nbuf,"%02llx",x); filler(buf,nbuf,NULL,0); } return 0; } static int chunkfs_open(const char *path,struct fuse_file_info *fi){ int r; struct chunk_stat st; if((r=resolve_path(path,&st))<0)return r; if((fi->flags&O_ACCMODE)!=O_RDONLY)return -EROFS; return 0; } static int chunkfs_read(const char *path,char *buf,size_t count,off_t offset,struct fuse_file_info *fi){ int r; struct chunk_stat st; ssize_t bufpos,r2; if((r=resolve_path(path,&st))<0)return r; if(S_ISDIR(st.mode))return -EISDIR; if(count>INT_MAX)die(false,"read request larger than can be represented in an int"); if(count>SSIZE_MAX)die(false,"read request larger than can be represented in an ssize_t"); count=min((off_t)count,max(st.size-offset,(off_t)0)); for(bufpos=0;bufpos ",*argv); errno=0; chunk_size=strtoll(argv[optind],&end,10); if(errno||*end||chunk_size<1)die(false,"Specified invalid chunk size"); if((image_fd=open(argv[optind+1],O_RDONLY))<0)die(true,"open(image)"); if(fstat(image_fd,&st)<0)die(true,"stat(image)"); if(S_ISBLK(st.st_mode)){ uint64_t blksize; if(ioctl(image_fd,BLKGETSIZE64,&blksize)<0)die(true,"ioctl(image,BLKGETSIZE64)"); if(blksize>(uint64_t)INT64_MAX)die(false,"block device too large"); image_size=blksize; }else{ image_size=st.st_size; } image_chunks=image_size/chunk_size; if(image_size%chunk_size)image_chunks++; argv[optind]=argv[optind+2]; argc-=2; return fuse_main(argc,argv,&chunkfs_ops); } chunkfs-0.4/debian/000075500000000000000000000000001120515224300142315ustar00rootroot00000000000000chunkfs-0.4/debian/changelog000064400000000000000000000011271120515224300161040ustar00rootroot00000000000000chunkfs (0.4) unstable; urgency=low * fixed read errors being ignored because of size_t being used where ssize_t should be -- Florian Zumbiehl Wed, 23 Jul 2008 10:18:36 +0200 chunkfs (0.3) unstable; urgency=low * Added writeoverlay.sh -- Florian Zumbiehl Thu, 5 Jul 2007 03:48:03 +0200 chunkfs (0.2) unstable; urgency=low * Added UnChunkFS -- Florian Zumbiehl Wed, 27 Jun 2007 00:08:38 +0200 chunkfs (0.1) unstable; urgency=low * Initial release -- Florian Zumbiehl Mon, 20 Jun 2007 18:29:09 +0200 chunkfs-0.4/debian/compat000064400000000000000000000000021120515224300154270ustar00rootroot000000000000005 chunkfs-0.4/debian/control000064400000000000000000000014671120515224300156440ustar00rootroot00000000000000Source: chunkfs Section: unknown Priority: extra Maintainer: Florian Zumbiehl Build-Depends: debhelper (>= 5), libfuse-dev (>= 2.5), perl Standards-Version: 3.7.2 Package: chunkfs Architecture: any Depends: ${shlibs:Depends}, fuse-utils Description: Mount arbitrary files via FUSE as a tree of chunk files. ChunkFS allows you to mount an arbitrary file or block device as a directory tree of read-only files that each represent a chunk of user-specified size of the mounted file. . A possible use for this is space-efficient incremental backups of encrypted filesystem images using rsync's --link-dest option. . The package also contains UnChunkFs, which allows you to mount a ChunkFS tree as an image file that mirrors the contents of whatever file or device the ChunkFS tree was created from. chunkfs-0.4/debian/copyright000064400000000000000000000017341120515224300161710ustar00rootroot00000000000000 ChunkFS - mount arbitrary files via FUSE as a tree of chunk files Copyright (C) 2007 Florian Zumbiehl This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. On Debian systems, the complete text of the GNU General Public License, version 2, can be found in /usr/share/common-licenses/GPL-2. chunkfs-0.4/debian/dirs000064400000000000000000000000331120515224300151110ustar00rootroot00000000000000usr/bin usr/share/man/man1 chunkfs-0.4/debian/rules000075500000000000000000000023721120515224300153150ustar00rootroot00000000000000#!/usr/bin/make -f # -*- makefile -*- # Sample debian/rules that uses debhelper. # This file was originally written by Joey Hess and Craig Small. # As a special exception, when this file is copied by dh-make into a # dh-make output file, you may use that output file without restriction. # This special exception was added by Craig Small in version 0.37 of dh-make. # Uncomment this to turn on verbose mode. #export DH_VERBOSE=1 configure: configure-stamp configure-stamp: dh_testdir touch configure-stamp build: build-stamp build-stamp: configure-stamp dh_testdir $(MAKE) touch $@ clean: dh_testdir dh_testroot rm -f build-stamp configure-stamp -$(MAKE) clean dh_clean install: build dh_testdir dh_testroot dh_clean -k dh_installdirs $(MAKE) DESTDIR=$(CURDIR)/debian/chunkfs PREFIX=/usr install # Build architecture-independent files here. binary-indep: build install # We have nothing to do by default. # Build architecture-dependent files here. binary-arch: build install dh_testdir dh_testroot dh_installchangelogs dh_installdocs dh_strip dh_compress dh_fixperms dh_installdeb dh_shlibdeps dh_gencontrol dh_md5sums dh_builddeb binary: binary-indep binary-arch .PHONY: build clean binary-indep binary-arch binary install configure chunkfs-0.4/manpage.pod000064400000000000000000000126461120515224300151340ustar00rootroot00000000000000 =head1 NAME chunkfs - mount arbitrary files via FUSE as a tree of chunk files =head1 SYNOPSIS B { B<-h> | > > > } B { B<-h> | > > } =head1 DESCRIPTION ChunkFS allows you to mount an arbitrary file or block device as a directory tree of read-only files that each represent a chunk of user-specified size of the mounted file. A possible use for this is space-efficient incremental backups of encrypted filesystem images using rsync's --link-dest option. That way you can create incremental backups from the ChunkFS-mounted image where any chunk that hasn't changed since the last backup will be a hard link to the corresponding chunk from the previous backup. In order to restore a revision, you simply have to concatenate all the chunks from the backup. Or you could use UnCunkFS to mount a ChunkFS tree (or a copy of one) as an image file. > is the size of the chunks into which > is to be divided when mounted at >, specified in bytes. If the mounted file's size is not a multiple of the >, the last file in the tree simply will be smaller than the chunk size. In case of UnChunkFS, > is the directory that contains a ChunkFS tree (or a copy of one) that is to be mounted at >. The chunk files of a ChunkFS are always at the eightth level of the mounted directory tree, if there are any (that is: if the image file is at least one byte in size). The concatenation of the path components from the root of the filesystem to a file gives you the hexadecimal representation of the number of the chunk that can be found in that respective file. This layout allows you to even incrementally backup files that have changed in size, as long as you do mount the ChunkFS with the same chunk size. Note, however, that ChunkFS does not cope well with image files that change their size while they are mounted. It shouldn't crash, but you will not be able to access any newly-allocated space and you will immediately hit end of file, or maybe even get other errors, if you try to read from a chunk file for which there is no data in the image file anymore. With UnChunkFS, you will always have exactly one file below the mount point, named B. The permissions of the files within the ChunkFS are derived from the permissions of the image file. Owner and group are simply inherited. The mode of all objects is the same as that of the image file, except that any executable bits are cleared for files, while directories have their executable bits set for exactly those entities (owner, group, others) that also have read permission. In the same way, UnChunkFS derives ownership and permissions for its root directory and the image file from the root of the mounted ChunkFS tree. But see below for what all these permissions actually effect. =head1 OPTIONS Actually, there are quite a few options provided by the FUSE library. For most of those, I don't even know what they do and there doesn't seem to be any documentation. If you run chunkfs with the B<-h> option, you will get a list of those options. Don't get confused by the fact that the FUSE library also tells you a synopsis that contradicts what's stated in this man page--I simply don't know how to stop libfuse from telling you that nonsense. Note that, by default, the permissions described above are used for presentation only, not for actual permission checking. You might want to use B<­o default_permissions> to change that, and maybe B<-o allow_other> to actually allow others to access your ChunkFS mount. =head1 EXAMPLES chunkfs 1048576 supersecretcryptoimage forbackup This gives you 1 MiB chunks of supersecretcryptoimage mounted below forbackup. unchunkfs forbackup forrestore mount -o loop forrestore/image gimmebackmydata When it's time for a restore. chunkfs 1 /dev/hda myharddiskinpieces You always wanted to examine every byte on your hard disk individually, right? If you want to use (Un)ChunkFS with block device snapshots, you might anticipate the problem that the snapshot of a journalling filesystem usually will need a log replay before it can be mounted--but you can't do any log replay on a read-only image like that provided by UnChunkFS, of course. As a possible solution, there is a B script included in this package's documentation directory that allows you to create from an arbitrary read-only block device a writable one by the means of the Linux device mapper's snapshot facility. Any writes to that device will be redirected to a temporary file. Make sure you read at the very least the comments within the script before you use it, as I wouldn't consider it production quality. =head1 COPYRIGHT Copyright (C) 2007 Florian Zumbiehl This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. chunkfs-0.4/unchunkfs.c000064400000000000000000000127051120515224300151640ustar00rootroot00000000000000/* * ChunkFS - mount arbitrary files via FUSE as a tree of chunk files * Copyright (C) 2007 Florian Zumbiehl * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #define _FILE_OFFSET_BITS 64 #define _XOPEN_SOURCE 500 #define FUSE_USE_VERSION 25 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "utils.h" static int chunkdir_fd; static off_t chunk_size,image_size; static int ensure_chunkdir_is_cwd(){ static bool done; if(!done){ if(fchdir(chunkdir_fd)<0)return -errno; done=true; } return 0; } static int resolve_path(const char *path,mode_t *mode){ if(!strcmp(path,"/")){ *mode=S_IFDIR; }else if(!strcmp(path,"/image")){ *mode=S_IFREG; }else{ return -ENOENT; } return 0; } static void gen_chunk_name(char *buf,off_t num){ sprintf(buf+7,"%016llx",num); for(int x=0;x<7;x++){ memmove(buf+x*3,buf+7+x*2,2); buf[x*3+2]='/'; } } static int unchunkfs_getattr(const char *path,struct stat *buf){ int r; mode_t mode; if((r=resolve_path(path,&mode))<0)return r; if(fstat(chunkdir_fd,buf)<0)return -errno; buf->st_mode=(buf->st_mode&~(S_IFMT|S_IXUSR|S_IXGRP|S_IXOTH))|(mode&S_IFMT); if(S_ISDIR(mode)){ buf->st_mode=buf->st_mode |((buf->st_mode&S_IRUSR)?S_IXUSR:0) |((buf->st_mode&S_IRGRP)?S_IXGRP:0) |((buf->st_mode&S_IROTH)?S_IXOTH:0); buf->st_nlink=2; buf->st_size=0; }else{ buf->st_nlink=1; buf->st_size=image_size; } buf->st_blocks=0; return 0; } static int unchunkfs_readdir(const char *path,void *buf,fuse_fill_dir_t filler,off_t offset,struct fuse_file_info *fi){ int r; mode_t mode; if((r=resolve_path(path,&mode))<0)return r; if(!S_ISDIR(mode))return -ENOTDIR; filler(buf,".",NULL,0); filler(buf,"..",NULL,0); filler(buf,"image",NULL,0); return 0; } static int unchunkfs_open(const char *path,struct fuse_file_info *fi){ int r; mode_t mode; if((r=resolve_path(path,&mode))<0)return r; if((fi->flags&O_ACCMODE)!=O_RDONLY)return -EROFS; return 0; } static int unchunkfs_read(const char *path,char *buf,size_t count,off_t offset,struct fuse_file_info *fi){ int r,chunk_fd; mode_t mode; off_t chunk_num,chunk_offset; char chunk_name[24]; ssize_t bufpos,r2; if(ensure_chunkdir_is_cwd()<0)return -EIO; if((r=resolve_path(path,&mode))<0)return r; if(S_ISDIR(mode))return -EISDIR; if(count>INT_MAX)die(false,"read request larger than can be represented in an int"); if(count>SSIZE_MAX)die(false,"read request larger than can be represented in an ssize_t"); count=min((off_t)count,max(image_size-offset,(off_t)0)); for(bufpos=0;bufpos ",*argv); if((cwd_fd=open(".",O_RDONLY))<0)die(true,"open(.)"); if((chunkdir_fd=open(argv[optind],O_RDONLY))<0)die(true,"open()"); if(fchdir(chunkdir_fd)<0)die(true,"fchdir()"); last_chunk=0; last_chunk_size=0; for(int x=64;x--;){ off_t new_last_chunk; char chunk_name[24]; new_last_chunk=last_chunk|(x<63?(off_t)1</%s)",chunk_name); }else{ if(st.st_size<1)die(false,"/%s is smaller than one byte",chunk_name); if(!chunk_size)chunk_size=st.st_size; last_chunk=new_last_chunk; last_chunk_size=st.st_size; } } if(chunk_size<1)chunk_size=1; if(last_chunk>ANYSINT_MAX(off_t)/chunk_size)die(false,"the sum of the chunks is too large"); image_size=last_chunk*chunk_size; if(last_chunk_size>ANYSINT_MAX(off_t)-image_size)die(false,"the sum of the chunks is too large"); image_size+=last_chunk_size; argv[optind]=argv[optind+1]; argc--; if(fchdir(cwd_fd)<0)die(true,"fchdir()"); return fuse_main(argc,argv,&unchunkfs_ops); } chunkfs-0.4/utils.c000064400000000000000000000005461120515224300143200ustar00rootroot00000000000000 #include #include #include #include #include "utils.h" void die(bool syserr,const char *fmt,...){ va_list ap; char buf[1024]; va_start(ap,fmt); vsnprintf(buf,sizeof(buf),fmt,ap); buf[sizeof(buf)-1]=0; if(syserr)syslog(LOG_ERR,"%s: %m, exiting",buf); else syslog(LOG_ERR,"%s, exiting",buf); exit(1); } chunkfs-0.4/utils.h000064400000000000000000000004201120515224300143140ustar00rootroot00000000000000 #include #include #define min(a,b) (((a)<(b))?(a):(b)) #define max(a,b) (((a)>(b))?(a):(b)) #define ANYSINT_MAX(t) ((((t)1<<(sizeof(t)*CHAR_BIT-2))-(t)1)*(t)2+(t)1) void die(bool,const char *,...) __attribute__ ((noreturn,format (printf,2,3))); chunkfs-0.4/writeoverlay.sh000075500000000000000000000045021120515224300161030ustar00rootroot00000000000000#!/bin/sh # # Copyright (C) 2007 Florian Zumbiehl # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program; if not, write to the Free Software Foundation, Inc., # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. # # # !!! Be warned that this script isn't very sophisticated in terms of !!! # !!! error handling and the handling of special characters in arguments! !!! # # This script allows you to create from an arbitrary block device a # writable clone by the means of the Linux device mapper's snapshot # facilities. Any writes to the clone will be stored in a temporary file. # # The primary intended use for this is to allow for read-only filesystem # images (like from backups) to be mounted, even if they need some form # of recovery, like a log replay in case of a journalling filesystem. # That's a common problem if the image was created from a block device # snapshot of a live filesystem. # # If the image is a regular file, you'll first have to create a loop # device from that, and then use this script on that loop device. # set -e #set -x usage(){ echo usage: $0 '[ create | remove ]' exit 1 } case "$1" in create) [ $# -eq 5 ] || usage ORIGDEV=$2 COWSIZE=$3 SECT_PER_CHUNK=$4 OVERLAYDEV=$5 COWFILE=`mktemp -t writeoverlay.XXXXXXXXXX` dd if=/dev/zero bs=1 seek=$COWSIZE count=1 of=$COWFILE > /dev/null LOOPDEV=`losetup -f` losetup $LOOPDEV $COWFILE rm $COWFILE echo "0 `blockdev --getsz $ORIGDEV` snapshot $ORIGDEV $LOOPDEV n $SECT_PER_CHUNK" | dmsetup create $OVERLAYDEV ;; remove) [ $# -eq 2 ] || usage OVERLAYDEV=$2 LOOPDEV=/dev/loop`dmsetup table $OVERLAYDEV | cut '-d ' -f5 | cut -d: -f2` dmsetup remove $OVERLAYDEV losetup -d $LOOPDEV ;; *) usage ;; esac