#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
+#include <sys/sysmacros.h>
#include <sys/types.h>
#include <unistd.h>
#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. */
/* 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
/* Read data from a file descriptor and return the amount of data read. A
* short read (less than the requested size) will only occur if end-of-file is
* hit. */
-size_t file_read(int fd, char *buf, size_t maxlen)
+ssize_t file_read(int fd, char *buf, size_t maxlen)
{
size_t bytes_read = 0;
if (res < 0) {
if (errno == EINTR)
continue;
- throw IOException("file_read: error reading");
+ fprintf(stderr, "error reading file: %m\n");
+ return -1;
} else if (res == 0) {
break;
} else {
/* Read the contents of a file (specified by an open file descriptor) and copy
* 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)
+int64_t dumpfile(int fd, dictionary &file_info, const string &path,
+ struct stat& stat_buf)
{
- struct stat stat_buf;
- fstat(fd, &stat_buf);
int64_t size = 0;
list<string> object_list;
- if ((stat_buf.st_mode & S_IFMT) != S_IFREG) {
- fprintf(stderr, "file is no longer a regular file!\n");
- return -1;
- }
-
/* 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. */
SHA1Checksum hash;
while (true) {
- size_t bytes = file_read(fd, block_buf, LBS_BLOCK_SIZE);
+ ssize_t bytes = file_read(fd, block_buf, LBS_BLOCK_SIZE);
if (bytes == 0)
break;
+ if (bytes < 0) {
+ fprintf(stderr, "Backup contents for %s may be incorrect\n",
+ path.c_str());
+ break;
+ }
hash.process(block_buf, bytes);
return size;
}
-void scanfile(const string& path, bool include)
+/* Dump a specified filesystem object (file, directory, etc.) based on its
+ * inode information. If the object is a regular file, an open filehandle is
+ * provided. */
+void dump_inode(const string& path, // Path within snapshot
+ const string& fullpath, // Path to object in filesystem
+ struct stat& stat_buf, // Results of stat() call
+ int fd) // Open filehandle if regular file
{
- 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(true_path.c_str(), &stat_buf);
+ int64_t file_size;
+ ssize_t len;
printf("%s\n", path.c_str());
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(true_path.c_str(), buf, stat_buf.st_size + 1);
+ len = readlink(fullpath.c_str(), buf, stat_buf.st_size + 1);
if (len < 0) {
fprintf(stderr, "error reading symlink: %m\n");
} else if (len <= stat_buf.st_size) {
case S_IFREG:
inode_type = '-';
- /* Be paranoid when opening the file. We have no guarantee that the
- * file was not replaced between the stat() call above and the open()
- * call below, so we might not even be opening a regular file. That
- * the file descriptor refers to a regular file is checked in
- * dumpfile(). But we also supply flags to open to to guard against
- * various conditions before we can perform that verification:
- * - O_NOFOLLOW: in the event the file was replaced by a symlink
- * - 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). 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_size = dumpfile(fd, file_info, path);
+ file_size = dumpfile(fd, file_info, path, stat_buf);
file_info["size"] = encode_int(file_size);
close(fd);
break;
case S_IFDIR:
inode_type = 'd';
- recurse = true;
break;
default:
// 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, include);
}
-void scandir(const string& path, bool include)
+void scanfile(const string& path, bool include)
{
+ int fd = -1;
+ long flags;
+ struct stat stat_buf;
+ list<string> refs;
+
string true_path;
if (relative_paths)
true_path = path;
else
true_path = "/" + path;
- DIR *dir = opendir(true_path.c_str());
+ // Set to true if we should scan through the contents of this directory,
+ // but not actually back files up
+ bool scan_only = false;
- if (dir == NULL) {
- fprintf(stderr, "Error: %m\n");
- return;
+ // 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;
+ }
}
- struct dirent *ent;
- vector<string> contents;
- while ((ent = readdir(dir)) != NULL) {
- string filename(ent->d_name);
- if (filename == "." || filename == "..")
- continue;
- contents.push_back(filename);
+ 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;
+
+ if (lstat(true_path.c_str(), &stat_buf) < 0) {
+ fprintf(stderr, "lstat(%s): %m\n", path.c_str());
+ return;
}
- sort(contents.begin(), contents.end());
+ if ((stat_buf.st_mode & S_IFMT) == S_IFREG) {
+ /* Be paranoid when opening the file. We have no guarantee that the
+ * file was not replaced between the stat() call above and the open()
+ * call below, so we might not even be opening a regular file. We
+ * supply flags to open to to guard against various conditions before
+ * we can perform an lstat to check that the file is still a regular
+ * file:
+ * - O_NOFOLLOW: in the event the file was replaced by a symlink
+ * - 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). 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);
- for (vector<string>::iterator i = contents.begin();
- i != contents.end(); ++i) {
- const string& filename = *i;
- if (path == ".")
- scanfile(filename, include);
- else
- scanfile(path + "/" + filename, include);
+ /* Perform the stat call again, and check that we still have a regular
+ * file. */
+ if (fstat(fd, &stat_buf) < 0) {
+ fprintf(stderr, "fstat: %m\n");
+ close(fd);
+ return;
+ }
+
+ if ((stat_buf.st_mode & S_IFMT) != S_IFREG) {
+ fprintf(stderr, "file is no longer a regular file!\n");
+ close(fd);
+ return;
+ }
}
- closedir(dir);
+ dump_inode(path, true_path, stat_buf, fd);
+
+ if (fd >= 0)
+ close(fd);
+
+ // If we hit a directory, now that we've written the directory itself,
+ // recursively scan the directory.
+ if ((stat_buf.st_mode & S_IFMT) == S_IFDIR) {
+ DIR *dir = opendir(true_path.c_str());
+
+ if (dir == NULL) {
+ fprintf(stderr, "Error: %m\n");
+ return;
+ }
+
+ struct dirent *ent;
+ vector<string> contents;
+ while ((ent = readdir(dir)) != NULL) {
+ string filename(ent->d_name);
+ if (filename == "." || filename == "..")
+ continue;
+ contents.push_back(filename);
+ }
+
+ closedir(dir);
+
+ sort(contents.begin(), contents.end());
+
+ for (vector<string>::iterator i = contents.begin();
+ i != contents.end(); ++i) {
+ const string& filename = *i;
+ if (path == ".")
+ scanfile(filename, include);
+ else
+ scanfile(path + "/" + filename, include);
+ }
+ }
}
/* Include the specified file path in the backups. Append the path to the
{
list<string>::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());
std::ofstream descriptor(desc_filename.c_str());
descriptor << "Format: LBS Snapshot v0.1\n";
+ descriptor << "Producer: LBS " << 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";
projects / cumulus.git / blobdiff