X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=scandir.cc;h=d50867ae4bf0f5a76b1e6bbe20266a6a279d2783;hb=908cfc1af3e761d3243d31a68420fb8994840721;hp=7c940f5d214b6d1de439372a58221d0b1db83ce6;hpb=03e760560aa77aa4f29de0610f41b547ac43ed00;p=cumulus.git diff --git a/scandir.cc b/scandir.cc index 7c940f5..d50867a 100644 --- a/scandir.cc +++ b/scandir.cc @@ -1,4 +1,25 @@ -/* Recursively descend the filesystem and visit each file. */ +/* Cumulus: Smart Filesystem Backup to Dumb Servers + * + * Copyright (C) 2006-2008 The Regents of the University of California + * Written by Michael Vrable + * + * 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. + */ + +/* Main entry point for LBS. Contains logic for traversing the filesystem and + * constructing a backup. */ #include #include @@ -26,8 +47,10 @@ #include "localdb.h" #include "metadata.h" +#include "remote.h" #include "store.h" #include "sha1.h" +#include "subfile.h" #include "util.h" using std::list; @@ -43,6 +66,7 @@ using std::ostream; #define LBS_STRINGIFY2(s) #s static const char lbs_version[] = LBS_STRINGIFY(LBS_VERSION); +static RemoteStore *remote = NULL; static TarSegmentStore *tss = NULL; static MetadataWriter *metawriter = NULL; @@ -57,6 +81,11 @@ LocalDb *db; /* Keep track of all segments which are needed to reconstruct the snapshot. */ std::set segment_list; +/* Snapshot intent: 1=daily, 7=weekly, etc. This is not used directly, but is + * stored in the local database and can help guide segment cleaning and + * snapshot expiration policies. */ +double snapshot_intent = 1.0; + /* Selection of files to include/exclude in the snapshot. */ std::list includes; // Paths in which files should be saved std::list excludes; // Paths which will not be saved @@ -111,17 +140,23 @@ int64_t dumpfile(int fd, dictionary &file_info, const string &path, /* Look up this file in the old stat cache, if we can. If the stat * information indicates that the file has not changed, do not bother - * re-reading the entire contents. */ + * re-reading the entire contents. Even if the information has been + * changed, we can use the list of old blocks in the search for a sub-block + * incremental representation. */ bool cached = false; + list old_blocks; + + bool found = metawriter->find(path); + if (found) + old_blocks = metawriter->get_blocks(); - if (metawriter->matched() && metawriter->is_unchanged(&stat_buf)) { + if (found && metawriter->is_unchanged(&stat_buf)) { cached = true; - list blocks = metawriter->get_blocks(); /* If any of the blocks in the object have been expired, then we should * fall back to fully reading in the file. */ - for (list::const_iterator i = blocks.begin(); - i != blocks.end(); ++i) { + for (list::const_iterator i = old_blocks.begin(); + i != old_blocks.end(); ++i) { const ObjectReference &ref = *i; if (!db->IsAvailable(ref)) { cached = false; @@ -133,11 +168,12 @@ int64_t dumpfile(int fd, dictionary &file_info, const string &path, /* If everything looks okay, use the cached information */ if (cached) { file_info["checksum"] = metawriter->get_checksum(); - for (list::const_iterator i = blocks.begin(); - i != blocks.end(); ++i) { + for (list::const_iterator i = old_blocks.begin(); + i != old_blocks.end(); ++i) { const ObjectReference &ref = *i; object_list.push_back(ref.to_string()); - segment_list.insert(ref.get_segment()); + if (ref.is_normal()) + add_segment(ref.get_segment()); db->UseObject(ref); } size = stat_buf.st_size; @@ -148,6 +184,9 @@ int64_t dumpfile(int fd, dictionary &file_info, const string &path, * time. */ if (!cached) { SHA1Checksum hash; + Subfile subfile(db); + subfile.load_old_blocks(old_blocks); + while (true) { ssize_t bytes = file_read(fd, block_buf, LBS_BLOCK_SIZE); if (bytes == 0) @@ -160,16 +199,36 @@ int64_t dumpfile(int fd, dictionary &file_info, const string &path, hash.process(block_buf, bytes); + // Sparse file processing: if we read a block of all zeroes, encode + // that explicitly. + bool all_zero = true; + for (int i = 0; i < bytes; i++) { + if (block_buf[i] != 0) { + all_zero = false; + break; + } + } + // Either find a copy of this block in an already-existing segment, // or index it so it can be re-used in the future double block_age = 0.0; + ObjectReference ref; + SHA1Checksum block_hash; block_hash.process(block_buf, bytes); string block_csum = block_hash.checksum_str(); - ObjectReference ref = db->FindObject(block_csum, bytes); + + if (all_zero) { + ref = ObjectReference(ObjectReference::REF_ZERO); + ref.set_range(0, bytes); + } else { + ref = db->FindObject(block_csum, bytes); + } + + list refs; // Store a copy of the object if one does not yet exist - if (ref.get_segment().size() == 0) { + if (ref.is_null()) { LbsObject *o = new LbsObject; int object_group; @@ -200,16 +259,19 @@ int64_t dumpfile(int fd, dictionary &file_info, const string &path, status = "new"; } - o->set_data(block_buf, bytes); - o->write(tss); - ref = o->get_ref(); - db->StoreObject(ref, block_csum, bytes, block_age); - delete o; + subfile.analyze_new_block(block_buf, bytes); + refs = subfile.create_incremental(tss, o, block_age); + } else { + refs.push_back(ref); } - object_list.push_back(ref.to_string()); - segment_list.insert(ref.get_segment()); - db->UseObject(ref); + while (!refs.empty()) { + ref = refs.front(); refs.pop_front(); + object_list.push_back(ref.to_string()); + if (ref.is_normal()) + add_segment(ref.get_segment()); + db->UseObject(ref); + } size += bytes; if (status == NULL) @@ -248,7 +310,6 @@ void dump_inode(const string& path, // Path within snapshot ssize_t len; printf("%s\n", path.c_str()); - metawriter->find(path); file_info["name"] = uri_encode(path); @@ -258,6 +319,11 @@ void dump_inode(const string& path, // Path within snapshot file_info["user"] = encode_int(stat_buf.st_uid); file_info["group"] = encode_int(stat_buf.st_gid); + time_t now = time(NULL); + if (now - stat_buf.st_ctime < 30 || now - stat_buf.st_mtime < 30) + if ((stat_buf.st_mode & S_IFMT) != S_IFDIR) + file_info["volatile"] = "1"; + struct passwd *pwd = getpwuid(stat_buf.st_uid); if (pwd != NULL) { file_info["user"] += " (" + uri_encode(pwd->pw_name) + ")"; @@ -322,6 +388,7 @@ void dump_inode(const string& path, // Path within snapshot if (file_size != stat_buf.st_size) { fprintf(stderr, "Warning: Size of %s changed during reading\n", path.c_str()); + file_info["volatile"] = "1"; } break; @@ -361,7 +428,6 @@ void scanfile(const string& path, bool include) for (list::iterator i = includes.begin(); i != includes.end(); ++i) { if (path == *i) { - printf("Including %s\n", path.c_str()); include = true; } } @@ -369,7 +435,6 @@ void scanfile(const string& path, bool include) for (list::iterator i = excludes.begin(); i != excludes.end(); ++i) { if (path == *i) { - printf("Excluding %s\n", path.c_str()); include = false; } } @@ -377,7 +442,6 @@ void scanfile(const string& path, bool include) for (list::iterator i = searches.begin(); i != searches.end(); ++i) { if (path == *i) { - printf("Scanning %s\n", path.c_str()); scan_only = true; } } @@ -478,7 +542,6 @@ void scanfile(const string& path, bool include) * themselves are excluded from being backed up. */ void add_include(const char *path) { - printf("Add: %s\n", path); /* Was an absolute path specified? If so, we'll need to start scanning * from the root directory. Make sure that the user was consistent in * providing either all relative paths or all absolute paths. */ @@ -522,9 +585,13 @@ void usage(const char *program) "Produce backup snapshot of files in SOURCE and store to DEST.\n" "\n" "Options:\n" - " --dest=PATH path where backup is to be written [REQUIRED]\n" + " --dest=PATH path where backup is to be written\n" + " --upload-script=COMMAND\n" + " program to invoke for each backup file generated\n" " --exclude=PATH exclude files in PATH from snapshot\n" " --localdb=PATH local backup metadata is stored in PATH\n" + " --tmpdir=PATH path for temporarily storing backup files\n" + " (defaults to TMPDIR environment variable or /tmp)\n" " --filter=COMMAND program through which to filter segment data\n" " (defaults to \"bzip2 -c\")\n" " --filter-extension=EXT\n" @@ -532,18 +599,27 @@ void usage(const char *program) " (defaults to \".bz2\")\n" " --signature-filter=COMMAND\n" " program though which to filter descriptor\n" - " --scheme=NAME optional name for this snapshot\n", + " --scheme=NAME optional name for this snapshot\n" + " --intent=FLOAT intended backup type: 1=daily, 7=weekly, ...\n" + " (defaults to \"1\")\n" + " --full-metadata do not re-use metadata from previous backups\n" + "\n" + "Exactly one of --dest or --upload-script must be specified.\n", lbs_version, program ); } int main(int argc, char *argv[]) { - string backup_dest = ""; + string backup_dest = "", backup_script = ""; string localdb_dir = ""; string backup_scheme = ""; string signature_filter = ""; + string tmp_dir = "/tmp"; + if (getenv("TMPDIR") != NULL) + tmp_dir = getenv("TMPDIR"); + while (1) { static struct option long_options[] = { {"localdb", 1, 0, 0}, // 0 @@ -553,6 +629,10 @@ int main(int argc, char *argv[]) {"dest", 1, 0, 0}, // 4 {"scheme", 1, 0, 0}, // 5 {"signature-filter", 1, 0, 0}, // 6 + {"intent", 1, 0, 0}, // 7 + {"full-metadata", 0, 0, 0}, // 8 + {"tmpdir", 1, 0, 0}, // 9 + {"upload-script", 1, 0, 0}, // 10 {NULL, 0, 0, 0}, }; @@ -588,6 +668,20 @@ int main(int argc, char *argv[]) case 6: // --signature-filter signature_filter = optarg; break; + case 7: // --intent + snapshot_intent = atof(optarg); + if (snapshot_intent <= 0) + snapshot_intent = 1; + break; + case 8: // --full-metadata + flag_full_metadata = true; + break; + case 9: // --tmpdir + tmp_dir = optarg; + break; + case 10: // --upload-script + backup_script = optarg; + break; default: fprintf(stderr, "Unhandled long option!\n"); return 1; @@ -607,9 +701,16 @@ int main(int argc, char *argv[]) for (int i = optind; i < argc; i++) add_include(argv[i]); - if (backup_dest == "") { + if (backup_dest == "" && backup_script == "") { fprintf(stderr, - "Error: Backup destination must be specified with --dest=\n"); + "Error: Backup destination must be specified using --dest= or --upload-script=\n"); + usage(argv[0]); + return 1; + } + + if (backup_dest != "" && backup_script != "") { + fprintf(stderr, + "Error: Cannot specify both --dest= and --upload-script=\n"); usage(argv[0]); return 1; } @@ -618,31 +719,31 @@ int main(int argc, char *argv[]) if (localdb_dir == "") { localdb_dir = backup_dest; } - - // Dump paths for debugging/informational purposes - { - list::const_iterator i; - - printf("LBS Version: %s\n", lbs_version); - - printf("--dest=%s\n--localdb=%s\n\n", - backup_dest.c_str(), localdb_dir.c_str()); - - printf("Includes:\n"); - for (i = includes.begin(); i != includes.end(); ++i) - printf(" %s\n", i->c_str()); - - printf("Excludes:\n"); - for (i = excludes.begin(); i != excludes.end(); ++i) - printf(" %s\n", i->c_str()); - - printf("Searching:\n"); - for (i = searches.begin(); i != searches.end(); ++i) - printf(" %s\n", i->c_str()); + if (localdb_dir == "") { + fprintf(stderr, + "Error: Must specify local database path with --localdb=\n"); + usage(argv[0]); + return 1; } block_buf = new char[LBS_BLOCK_SIZE]; + /* Initialize the remote storage layer. If using an upload script, create + * a temporary directory for staging files. Otherwise, write backups + * directly to the destination directory. */ + if (backup_script != "") { + tmp_dir = tmp_dir + "/lbs." + generate_uuid(); + if (mkdir(tmp_dir.c_str(), 0700) < 0) { + fprintf(stderr, "Cannot create temporary directory %s: %m\n", + tmp_dir.c_str()); + return 1; + } + remote = new RemoteStore(tmp_dir); + remote->set_script(backup_script); + } else { + remote = new RemoteStore(backup_dest); + } + /* Store the time when the backup started, so it can be included in the * snapshot name. */ time_t now; @@ -658,9 +759,10 @@ int main(int argc, char *argv[]) string database_path = localdb_dir + "/localdb.sqlite"; db = new LocalDb; db->Open(database_path.c_str(), desc_buf, - backup_scheme.size() ? backup_scheme.c_str() : NULL); + backup_scheme.size() ? backup_scheme.c_str() : NULL, + snapshot_intent); - tss = new TarSegmentStore(backup_dest, db); + tss = new TarSegmentStore(remote, db); /* Initialize the stat cache, for skipping over unchanged files. */ metawriter = new MetadataWriter(tss, localdb_dir.c_str(), desc_buf, @@ -684,48 +786,56 @@ int main(int argc, char *argv[]) * segments included in this snapshot. The format is designed so that it * may be easily verified using the sha1sums command. */ const char csum_type[] = "sha1"; - string checksum_filename = backup_dest + "/snapshot-"; + string checksum_filename = "snapshot-"; if (backup_scheme.size() > 0) checksum_filename += backup_scheme + "-"; checksum_filename = checksum_filename + desc_buf + "." + csum_type + "sums"; - FILE *checksums = fopen(checksum_filename.c_str(), "w"); - if (checksums != NULL) { - for (std::set::iterator i = segment_list.begin(); - i != segment_list.end(); ++i) { - string seg_path, seg_csum; - if (db->GetSegmentChecksum(*i, &seg_path, &seg_csum)) { - const char *raw_checksum = NULL; - if (strncmp(seg_csum.c_str(), csum_type, - strlen(csum_type)) == 0) { - raw_checksum = seg_csum.c_str() + strlen(csum_type); - if (*raw_checksum == '=') - raw_checksum++; - else - raw_checksum = NULL; - } + RemoteFile *checksum_file = remote->alloc_file(checksum_filename, + "checksums"); + FILE *checksums = fdopen(checksum_file->get_fd(), "w"); - if (raw_checksum != NULL) - fprintf(checksums, "%s *%s\n", - raw_checksum, seg_path.c_str()); + for (std::set::iterator i = segment_list.begin(); + i != segment_list.end(); ++i) { + string seg_path, seg_csum; + if (db->GetSegmentChecksum(*i, &seg_path, &seg_csum)) { + const char *raw_checksum = NULL; + if (strncmp(seg_csum.c_str(), csum_type, + strlen(csum_type)) == 0) { + raw_checksum = seg_csum.c_str() + strlen(csum_type); + if (*raw_checksum == '=') + raw_checksum++; + else + raw_checksum = NULL; } + + if (raw_checksum != NULL) + fprintf(checksums, "%s *%s\n", + raw_checksum, seg_path.c_str()); } - fclose(checksums); - } else { - fprintf(stderr, "ERROR: Unable to write checksums file: %m\n"); } + fclose(checksums); + checksum_file->send(); db->Close(); + /* All other files should be flushed to remote storage before writing the + * backup descriptor below, so that it is not possible to have a backup + * descriptor written out depending on non-existent (not yet written) + * files. */ + remote->sync(); + /* Write a backup descriptor file, which says which segments are needed and * where to start to restore this snapshot. The filename is based on the * current time. If a signature filter program was specified, filter the * data through that to give a chance to sign the descriptor contents. */ - string desc_filename = backup_dest + "/snapshot-"; + string desc_filename = "snapshot-"; if (backup_scheme.size() > 0) desc_filename += backup_scheme + "-"; desc_filename = desc_filename + desc_buf + ".lbs"; - int descriptor_fd = open(desc_filename.c_str(), O_WRONLY | O_CREAT, 0666); + RemoteFile *descriptor_file = remote->alloc_file(desc_filename, + "snapshots"); + int descriptor_fd = descriptor_file->get_fd(); if (descriptor_fd < 0) { fprintf(stderr, "Unable to open descriptor output file: %m\n"); return 1; @@ -745,6 +855,7 @@ int main(int argc, char *argv[]) fprintf(descriptor, "Date: %s\n", desc_buf); if (backup_scheme.size() > 0) fprintf(descriptor, "Scheme: %s\n", backup_scheme.c_str()); + fprintf(descriptor, "Backup-Intent: %g\n", snapshot_intent); fprintf(descriptor, "Root: %s\n", backup_root.c_str()); SHA1Checksum checksum_csum; @@ -770,5 +881,18 @@ int main(int argc, char *argv[]) } } + descriptor_file->send(); + + remote->sync(); + delete remote; + + if (backup_script != "") { + if (rmdir(tmp_dir.c_str()) < 0) { + fprintf(stderr, + "Warning: Cannot delete temporary directory %s: %m\n", + tmp_dir.c_str()); + } + } + return 0; }