/* Recursively descend the filesystem and visit each file. */
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdint.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
-#include <sys/types.h>
+#include <getopt.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
#include <unistd.h>
#include <algorithm>
-#include <string>
-#include <list>
-#include <vector>
+#include <fstream>
#include <iostream>
+#include <list>
+#include <set>
#include <sstream>
+#include <string>
+#include <vector>
-#include "format.h"
+#include "localdb.h"
#include "store.h"
#include "sha1.h"
+#include "statcache.h"
+#include "util.h"
using std::list;
using std::string;
using std::vector;
using std::ostream;
+/* Version information. This will be filled in by the Makefile. */
+#ifndef LBS_VERSION
+#define LBS_VERSION Unknown
+#endif
+#define LBS_STRINGIFY(s) LBS_STRINGIFY2(s)
+#define LBS_STRINGIFY2(s) #s
+static const char lbs_version[] = LBS_STRINGIFY(LBS_VERSION);
+
static TarSegmentStore *tss = NULL;
/* Buffer for holding a single block of data read from a file. */
-static const int LBS_BLOCK_SIZE = 1024 * 1024;
+static const size_t LBS_BLOCK_SIZE = 1024 * 1024;
static char *block_buf;
-void scandir(const string& path, std::ostream& metadata);
+static const size_t LBS_METADATA_BLOCK_SIZE = 65536;
-/* Converts time to microseconds since the epoch. */
-int64_t encode_time(time_t time)
+/* Local database, which tracks objects written in this and previous
+ * invocations to help in creating incremental snapshots. */
+LocalDb *db;
+
+/* Stat cache, which stored data locally to speed the backup process by quickly
+ * skipping files which have not changed. */
+StatCache *statcache;
+
+/* Contents of the root object. This will contain a set of indirect links to
+ * the metadata objects. */
+std::ostringstream metadata_root;
+
+/* Buffer for building up metadata. */
+std::ostringstream metadata;
+
+/* Keep track of all segments which are needed to reconstruct the snapshot. */
+std::set<string> segment_list;
+
+void scandir(const string& path, bool include);
+
+/* Selection of files to include/exclude in the snapshot. */
+std::list<string> includes; // Paths in which files should be saved
+std::list<string> excludes; // Paths which will not be saved
+std::list<string> searches; // Directories we don't want to save, but
+ // do want to descend searching for data
+ // in included paths
+
+bool relative_paths = true;
+
+/* Ensure contents of metadata are flushed to an object. */
+void metadata_flush()
{
- return (int64_t)time * 1000000;
+ string m = metadata.str();
+ if (m.size() == 0)
+ return;
+
+ /* Write current metadata information to a new object. */
+ LbsObject *meta = new LbsObject;
+ meta->set_group("metadata");
+ meta->set_data(m.data(), m.size());
+ meta->write(tss);
+ meta->checksum();
+
+ /* Write a reference to this block in the root. */
+ ObjectReference ref = meta->get_ref();
+ metadata_root << "@" << ref.to_string() << "\n";
+ segment_list.insert(ref.get_segment());
+
+ delete meta;
+
+ metadata.str("");
}
/* Read data from a file descriptor and return the amount of data read. A
}
/* Read the contents of a file (specified by an open file descriptor) and copy
- * the data to the store. */
-void dumpfile(int fd, dictionary &file_info, ostream &metadata)
+ * the data to the store. Returns the size of the file (number of bytes
+ * dumped), or -1 on error. */
+int64_t dumpfile(int fd, dictionary &file_info, const string &path)
{
struct stat stat_buf;
fstat(fd, &stat_buf);
int64_t size = 0;
- list<string> segment_list;
+ list<string> object_list;
if ((stat_buf.st_mode & S_IFMT) != S_IFREG) {
- printf("file is no longer a regular file!\n");
- return;
+ fprintf(stderr, "file is no longer a regular file!\n");
+ return -1;
}
- /* The index data consists of a sequence of pointers to the data blocks
- * that actually comprise the file data. This level of indirection is used
- * so that the same data block can be used in multiple files, or multiple
- * versions of the same file. */
- SHA1Checksum hash;
- while (true) {
- size_t bytes = file_read(fd, block_buf, LBS_BLOCK_SIZE);
- if (bytes == 0)
- break;
+ /* 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. */
+ bool cached = false;
+
+ if (statcache->Find(path, &stat_buf)) {
+ cached = true;
+ const list<ObjectReference> &blocks = statcache->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<ObjectReference>::const_iterator i = blocks.begin();
+ i != blocks.end(); ++i) {
+ const ObjectReference &ref = *i;
+ if (!db->IsAvailable(ref)) {
+ cached = false;
+ break;
+ }
+ }
- hash.process(block_buf, bytes);
+ /* If everything looks okay, use the cached information */
+ if (cached) {
+ file_info["checksum"] = statcache->get_checksum();
+ for (list<ObjectReference>::const_iterator i = blocks.begin();
+ i != blocks.end(); ++i) {
+ const ObjectReference &ref = *i;
+ object_list.push_back(ref.to_string());
+ segment_list.insert(ref.get_segment());
+ db->UseObject(ref);
+ }
+ size = stat_buf.st_size;
+ }
+ }
- // tarstore processing
- string blockid = tss->write_object(block_buf, bytes, "data");
- segment_list.push_back(blockid);
+ /* If the file is new or changed, we must read in the contents a block at a
+ * time. */
+ if (!cached) {
+ printf(" [new]\n");
+
+ SHA1Checksum hash;
+ while (true) {
+ size_t bytes = file_read(fd, block_buf, LBS_BLOCK_SIZE);
+ if (bytes == 0)
+ break;
+
+ hash.process(block_buf, bytes);
+
+ // 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;
+ SHA1Checksum block_hash;
+ block_hash.process(block_buf, bytes);
+ string block_csum = block_hash.checksum_str();
+ ObjectReference ref = db->FindObject(block_csum, bytes);
+
+ // Store a copy of the object if one does not yet exist
+ if (ref.get_segment().size() == 0) {
+ LbsObject *o = new LbsObject;
+
+ /* We might still have seen this checksum before, if the object
+ * was stored at some time in the past, but we have decided to
+ * clean the segment the object was originally stored in
+ * (FindObject will not return such objects). When rewriting
+ * the object contents, put it in a separate group, so that old
+ * objects get grouped together. The hope is that these old
+ * objects will continue to be used in the future, and we
+ * obtain segments which will continue to be well-utilized.
+ * Additionally, keep track of the age of the data by looking
+ * up the age of the block which was expired and using that
+ * instead of the current time. */
+ if (db->IsOldObject(block_csum, bytes, &block_age))
+ o->set_group("compacted");
+ else
+ o->set_group("data");
+
+ o->set_data(block_buf, bytes);
+ o->write(tss);
+ ref = o->get_ref();
+ db->StoreObject(ref, block_csum, bytes, block_age);
+ delete o;
+ }
+
+ object_list.push_back(ref.to_string());
+ segment_list.insert(ref.get_segment());
+ db->UseObject(ref);
+ size += bytes;
+ }
- size += bytes;
+ file_info["checksum"] = hash.checksum_str();
}
- file_info["checksum"] = hash.checksum_str();
+ statcache->Save(path, &stat_buf, file_info["checksum"], object_list);
/* For files that only need to be broken apart into a few objects, store
* the list of objects directly. For larger files, store the data
* out-of-line and provide a pointer to the indrect object. */
- if (segment_list.size() < 8) {
+ if (object_list.size() < 8) {
string blocklist = "";
- for (list<string>::iterator i = segment_list.begin();
- i != segment_list.end(); ++i) {
- if (i != segment_list.begin())
+ for (list<string>::iterator i = object_list.begin();
+ i != object_list.end(); ++i) {
+ if (i != object_list.begin())
blocklist += " ";
blocklist += *i;
}
file_info["data"] = blocklist;
} else {
string blocklist = "";
- for (list<string>::iterator i = segment_list.begin();
- i != segment_list.end(); ++i) {
+ for (list<string>::iterator i = object_list.begin();
+ i != object_list.end(); ++i) {
blocklist += *i + "\n";
}
- string indirect = tss->write_object(blocklist.data(), blocklist.size(),
- "indirect");
- file_info["data"] = "@" + indirect;
+
+ LbsObject *i = new LbsObject;
+ i->set_group("metadata");
+ i->set_data(blocklist.data(), blocklist.size());
+ i->write(tss);
+ file_info["data"] = "@" + i->get_name();
+ segment_list.insert(i->get_ref().get_segment());
+ delete i;
}
+
+ return size;
}
-void scanfile(const string& path, ostream &metadata)
+void scanfile(const string& path, bool include)
{
int fd;
long flags;
struct stat stat_buf;
char *buf;
ssize_t len;
+ int64_t file_size;
list<string> refs;
+ string true_path;
+ if (relative_paths)
+ true_path = path;
+ else
+ true_path = "/" + path;
+
// Set to true if the item is a directory and we should recursively scan
bool recurse = false;
+ // Set to true if we should scan through the contents of this directory,
+ // but not actually back files up
+ bool scan_only = false;
+
+ // Check this file against the include/exclude list to see if it should be
+ // considered
+ for (list<string>::iterator i = includes.begin();
+ i != includes.end(); ++i) {
+ if (path == *i) {
+ printf("Including %s\n", path.c_str());
+ include = true;
+ }
+ }
+
+ for (list<string>::iterator i = excludes.begin();
+ i != excludes.end(); ++i) {
+ if (path == *i) {
+ printf("Excluding %s\n", path.c_str());
+ include = false;
+ }
+ }
+
+ for (list<string>::iterator i = searches.begin();
+ i != searches.end(); ++i) {
+ if (path == *i) {
+ printf("Scanning %s\n", path.c_str());
+ scan_only = true;
+ }
+ }
+
+ if (!include && !scan_only)
+ return;
+
dictionary file_info;
- lstat(path.c_str(), &stat_buf);
+ lstat(true_path.c_str(), &stat_buf);
printf("%s\n", path.c_str());
- metadata << "name: " << uri_encode(path) << "\n";
-
file_info["mode"] = encode_int(stat_buf.st_mode & 07777);
- file_info["atime"] = encode_int(stat_buf.st_atime);
- file_info["ctime"] = encode_int(stat_buf.st_ctime);
file_info["mtime"] = encode_int(stat_buf.st_mtime);
file_info["user"] = encode_int(stat_buf.st_uid);
file_info["group"] = encode_int(stat_buf.st_gid);
+ struct passwd *pwd = getpwuid(stat_buf.st_uid);
+ if (pwd != NULL) {
+ file_info["user"] += " (" + uri_encode(pwd->pw_name) + ")";
+ }
+
+ struct group *grp = getgrgid(stat_buf.st_gid);
+ if (pwd != NULL) {
+ file_info["group"] += " (" + uri_encode(grp->gr_name) + ")";
+ }
+
char inode_type;
switch (stat_buf.st_mode & S_IFMT) {
case S_IFSOCK:
inode_type = 's';
break;
- case S_IFCHR:
- inode_type = 'c';
- break;
case S_IFBLK:
- inode_type = 'b';
+ case S_IFCHR:
+ inode_type = ((stat_buf.st_mode & S_IFMT) == S_IFBLK) ? 'b' : 'c';
+ file_info["device"] = encode_int(major(stat_buf.st_rdev))
+ + "/" + encode_int(minor(stat_buf.st_rdev));
break;
case S_IFLNK:
inode_type = 'l';
* the symlink. Allocate slightly more space, so that we ask for more
* bytes than we expect and so check for truncation. */
buf = new char[stat_buf.st_size + 2];
- len = readlink(path.c_str(), buf, stat_buf.st_size + 1);
+ len = readlink(true_path.c_str(), buf, stat_buf.st_size + 1);
if (len < 0) {
- printf("error reading symlink: %m\n");
+ fprintf(stderr, "error reading symlink: %m\n");
} else if (len <= stat_buf.st_size) {
buf[len] = '\0';
- printf(" contents=%s\n", buf);
+ file_info["contents"] = uri_encode(buf);
} else if (len > stat_buf.st_size) {
- printf("error reading symlink: name truncated\n");
+ fprintf(stderr, "error reading symlink: name truncated\n");
}
- file_info["contents"] = uri_encode(buf);
-
delete[] buf;
break;
case S_IFREG:
* - O_NONBLOCK: prevents open() from blocking if the file was
* replaced by a fifo
* We also add in O_NOATIME, since this may reduce disk writes (for
- * inode updates). */
- fd = open(path.c_str(), O_RDONLY|O_NOATIME|O_NOFOLLOW|O_NONBLOCK);
+ * inode updates). However, O_NOATIME may result in EPERM, so if the
+ * initial open fails, try again without O_NOATIME. */
+ fd = open(true_path.c_str(), O_RDONLY|O_NOATIME|O_NOFOLLOW|O_NONBLOCK);
+ if (fd < 0) {
+ fd = open(true_path.c_str(), O_RDONLY|O_NOFOLLOW|O_NONBLOCK);
+ }
+ if (fd < 0) {
+ fprintf(stderr, "Unable to open file %s: %m\n", path.c_str());
+ return;
+ }
/* Drop the use of the O_NONBLOCK flag; we only wanted that for file
* open. */
flags = fcntl(fd, F_GETFL);
fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
- file_info["size"] = encode_int(stat_buf.st_size);
- dumpfile(fd, file_info, metadata);
+ file_size = dumpfile(fd, file_info, path);
+ file_info["size"] = encode_int(file_size);
close(fd);
+ if (file_size < 0)
+ return; // error occurred; do not dump file
+
+ if (file_size != stat_buf.st_size) {
+ fprintf(stderr, "Warning: Size of %s changed during reading\n",
+ path.c_str());
+ }
+
break;
case S_IFDIR:
inode_type = 'd';
}
file_info["type"] = string(1, inode_type);
- metadata << "type: " << inode_type << "\n";
+ metadata << "name: " << uri_encode(path) << "\n";
dict_output(metadata, file_info);
metadata << "\n";
+ // Break apart metadata listing if it becomes too large.
+ if (metadata.str().size() > LBS_METADATA_BLOCK_SIZE)
+ metadata_flush();
+
// If we hit a directory, now that we've written the directory itself,
// recursively scan the directory.
if (recurse)
- scandir(path, metadata);
+ scandir(path, include);
}
-void scandir(const string& path, ostream &metadata)
+void scandir(const string& path, bool include)
{
- DIR *dir = opendir(path.c_str());
+ string true_path;
+ if (relative_paths)
+ true_path = path;
+ else
+ true_path = "/" + path;
+
+ DIR *dir = opendir(true_path.c_str());
if (dir == NULL) {
- printf("Error: %m\n");
+ fprintf(stderr, "Error: %m\n");
return;
}
for (vector<string>::iterator i = contents.begin();
i != contents.end(); ++i) {
const string& filename = *i;
- scanfile(path + "/" + filename, metadata);
+ if (path == ".")
+ scanfile(filename, include);
+ else
+ scanfile(path + "/" + filename, include);
}
closedir(dir);
}
+/* Include the specified file path in the backups. Append the path to the
+ * includes list, and to ensure that we actually see the path when scanning the
+ * directory tree, add all the parent directories to the search list, which
+ * means we will scan through the directory listing even if the files
+ * 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. */
+ if (path[0] == '/') {
+ if (includes.size() > 0 && relative_paths == true) {
+ fprintf(stderr,
+ "Error: Cannot mix relative and absolute paths!\n");
+ exit(1);
+ }
+
+ relative_paths = false;
+
+ // Skip over leading '/'
+ path++;
+ } else if (relative_paths == false && path[0] != '/') {
+ fprintf(stderr, "Error: Cannot mix relative and absolute paths!\n");
+ exit(1);
+ }
+
+ includes.push_back(path);
+
+ /* Split the specified path into directory components, and ensure that we
+ * descend into all the directories along the path. */
+ const char *slash = path;
+
+ if (path[0] == '\0')
+ return;
+
+ while ((slash = strchr(slash + 1, '/')) != NULL) {
+ string component(path, slash - path);
+ searches.push_back(component);
+ }
+}
+
+void usage(const char *program)
+{
+ fprintf(
+ stderr,
+ "Usage: %s [OPTION]... --dest=DEST PATHS...\n"
+ "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"
+ " --exclude=PATH exclude files in PATH from snapshot\n"
+ " --localdb=PATH local backup metadata is stored in PATH\n"
+ " --filter=COMMAND program through which to filter segment data\n"
+ " (defaults to \"bzip2 -c\")\n"
+ " --filter-extension=EXT\n"
+ " string to append to segment files\n"
+ " (defaults to \".bz2\")\n",
+ program
+ );
+}
+
int main(int argc, char *argv[])
{
- block_buf = new char[LBS_BLOCK_SIZE];
+ string backup_source = ".";
+ string backup_dest = "";
+ string localdb_dir = "";
+
+ while (1) {
+ static struct option long_options[] = {
+ {"localdb", 1, 0, 0}, // 0
+ {"exclude", 1, 0, 0}, // 1
+ {"filter", 1, 0, 0}, // 2
+ {"filter-extension", 1, 0, 0}, // 3
+ {"dest", 1, 0, 0}, // 4
+ {NULL, 0, 0, 0},
+ };
+
+ int long_index;
+ int c = getopt_long(argc, argv, "", long_options, &long_index);
+
+ if (c == -1)
+ break;
- tss = new TarSegmentStore(".");
+ if (c == 0) {
+ switch (long_index) {
+ case 0: // --localdb
+ localdb_dir = optarg;
+ break;
+ case 1: // --exclude
+ if (optarg[0] != '/')
+ excludes.push_back(optarg);
+ else
+ excludes.push_back(optarg + 1);
+ break;
+ case 2: // --filter
+ filter_program = optarg;
+ break;
+ case 3: // --filter-extension
+ filter_extension = optarg;
+ break;
+ case 4: // --dest
+ backup_dest = optarg;
+ break;
+ default:
+ fprintf(stderr, "Unhandled long option!\n");
+ return 1;
+ }
+ } else {
+ usage(argv[0]);
+ return 1;
+ }
+ }
+
+ if (argc < optind + 2) {
+ usage(argv[0]);
+ return 1;
+ }
+
+ searches.push_back(".");
+ if (optind == argc) {
+ add_include(".");
+ } else {
+ for (int i = optind; i < argc; i++)
+ add_include(argv[i]);
+ }
+
+ backup_source = argv[optind];
+
+ if (backup_dest == "") {
+ fprintf(stderr,
+ "Error: Backup destination must be specified with --dest=\n");
+ usage(argv[0]);
+ return 1;
+ }
+
+ // Default for --localdb is the same as --dest
+ if (localdb_dir == "") {
+ localdb_dir = backup_dest;
+ }
+
+ // Dump paths for debugging/informational purposes
+ {
+ list<string>::const_iterator i;
+
+ printf("LBS Version: %s\n", lbs_version);
- std::ostringstream metadata;
+ printf("--dest=%s\n--localdb=%s\n\n",
+ backup_dest.c_str(), localdb_dir.c_str());
- try {
- scanfile(".", metadata);
- } catch (IOException e) {
- fprintf(stderr, "IOException: %s\n", e.getError().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());
}
- const string md = metadata.str();
- string root = tss->write_object(md.data(), md.size(), "root");
+ tss = new TarSegmentStore(backup_dest);
+ block_buf = new char[LBS_BLOCK_SIZE];
+
+ /* Store the time when the backup started, so it can be included in the
+ * snapshot name. */
+ time_t now;
+ struct tm time_buf;
+ char desc_buf[256];
+ time(&now);
+ localtime_r(&now, &time_buf);
+ strftime(desc_buf, sizeof(desc_buf), "%Y%m%dT%H%M%S", &time_buf);
+
+ /* Open the local database which tracks all objects that are stored
+ * remotely, for efficient incrementals. Provide it with the name of this
+ * snapshot. */
+ string database_path = localdb_dir + "/localdb.sqlite";
+ db = new LocalDb;
+ db->Open(database_path.c_str(), desc_buf);
+
+ /* Initialize the stat cache, for skipping over unchanged files. */
+ statcache = new StatCache;
+ statcache->Open(localdb_dir.c_str(), desc_buf);
+
+ scanfile(".", false);
+
+ metadata_flush();
+ const string md = metadata_root.str();
+
+ LbsObject *root = new LbsObject;
+ root->set_group("metadata");
+ root->set_data(md.data(), md.size());
+ root->write(tss);
+ root->checksum();
+ segment_list.insert(root->get_ref().get_segment());
+
+ string backup_root = root->get_ref().to_string();
+ delete root;
+
+ db->Close();
+
+ statcache->Close();
+ delete statcache;
tss->sync();
+ tss->dump_stats();
delete tss;
+ /* 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. */
+ string desc_filename = backup_dest + "/snapshot-" + desc_buf + ".lbs";
+ std::ofstream descriptor(desc_filename.c_str());
+
+ descriptor << "Format: LBS Snapshot v0.1\n";
+ descriptor << "Producer: " << lbs_version << "\n";
+ strftime(desc_buf, sizeof(desc_buf), "%Y-%m-%d %H:%M:%S %z", &time_buf);
+ descriptor << "Date: " << desc_buf << "\n";
+ descriptor << "Root: " << backup_root << "\n";
+
+ descriptor << "Segments:\n";
+ for (std::set<string>::iterator i = segment_list.begin();
+ i != segment_list.end(); ++i) {
+ descriptor << " " << *i << "\n";
+ }
+
return 0;
}
projects / cumulus.git / blobdiff