X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=src%2Fextract.c;h=bd5e7bf588daecfa0da25ef9fa1bc64957e1be8e;hb=6689e8db4f53f6a0bed3d1bc4ed12d31eaa3bf51;hp=0a1a032989d3d59a1aeb989f3bd6a3fe08ea1422;hpb=14efeb9f956e38d7beaf3fbedb04d3f3bb9ece3a;p=chaz%2Ftar diff --git a/src/extract.c b/src/extract.c index 0a1a032..bd5e7bf 100644 --- a/src/extract.c +++ b/src/extract.c @@ -110,12 +110,15 @@ struct delayed_link /* The next delayed link in the list. */ struct delayed_link *next; - /* The device, inode number and ctime of the placeholder. Use - ctime, not mtime, to make false matches less likely if some - other process removes the placeholder. */ + /* The device, inode number and birthtime of the placeholder. + birthtime.tv_nsec is negative if the birthtime is not available. + Don't use mtime as this would allow for false matches if some + other process removes the placeholder. Don't use ctime as + this would cause race conditions and other screwups, e.g., + when restoring hard-linked symlinks. */ dev_t dev; ino_t ino; - struct timespec ctime; + struct timespec birthtime; /* True if the link is symbolic. */ bool is_symlink; @@ -478,20 +481,20 @@ repair_delayed_set_stat (char const *dir, /* After a file/link/directory creation has failed, see if it's because some required directory was not present, and if so, - create all required directories. Return non-zero if a directory - was created. */ + create all required directories. Return zero if all the required + directories were created, nonzero (issuing a diagnostic) otherwise. + Set *INTERDIR_MADE if at least one directory was created. */ static int -make_directories (char *file_name) +make_directories (char *file_name, bool *interdir_made) { char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name); char *cursor; /* points into the file name */ - int did_something = 0; /* did we do anything yet? */ - int status; for (cursor = cursor0; *cursor; cursor++) { mode_t mode; mode_t desired_mode; + int status; if (! ISSLASH (*cursor)) continue; @@ -524,28 +527,32 @@ make_directories (char *file_name) desired_mode, AT_SYMLINK_NOFOLLOW); print_for_mkdir (file_name, cursor - file_name, desired_mode); - did_something = 1; - - *cursor = '/'; - continue; + *interdir_made = true; + } + else if (errno == EEXIST) + status = 0; + else + { + /* Check whether the desired file exists. Even when the + file exists, mkdir can fail with some errno value E other + than EEXIST, so long as E describes an error condition + that also applies. */ + int e = errno; + struct stat st; + status = fstatat (chdir_fd, file_name, &st, 0); + if (status) + { + errno = e; + mkdir_error (file_name); + } } *cursor = '/'; - - if (errno == EEXIST) - continue; /* Directory already exists. */ - else if ((errno == ENOSYS /* Automounted dirs on Solaris return - this. Reported by Warren Hyde - */ - || ERRNO_IS_EACCES) /* Turbo C mkdir gives a funny errno. */ - && faccessat (chdir_fd, file_name, W_OK, AT_EACCESS) == 0) - continue; - - /* Some other error in the mkdir. We return to the caller. */ - break; + if (status) + return status; } - return did_something; /* tell them to retry if we made one */ + return 0; } /* Return true if FILE_NAME (with status *STP, if STP) is not a @@ -605,6 +612,18 @@ maybe_recoverable (char *file_name, bool regular, bool *interdir_made) switch (e) { case ELOOP: + + /* With open ("symlink", O_NOFOLLOW|...), POSIX says errno == ELOOP, + but some operating systems do not conform to the standard. */ +#ifdef EFTYPE + /* NetBSD uses errno == EFTYPE; see . */ + case EFTYPE: +#endif + /* FreeBSD 8.1 uses errno == EMLINK. */ + case EMLINK: + /* Tru64 5.1B uses errno == ENOTSUP. */ + case ENOTSUP: + if (! regular || old_files_option != OVERWRITE_OLD_FILES || dereference_option) break; @@ -623,9 +642,14 @@ maybe_recoverable (char *file_name, bool regular, bool *interdir_made) switch (old_files_option) { - case KEEP_OLD_FILES: + case SKIP_OLD_FILES: + WARNOPT (WARN_EXISTING_FILE, + (0, 0, _("%s: skipping existing file"), file_name)); return RECOVER_SKIP; + case KEEP_OLD_FILES: + return RECOVER_NO; + case KEEP_NEWER_FILES: if (file_newer_p (file_name, stp, ¤t_stat_info)) break; @@ -644,11 +668,8 @@ maybe_recoverable (char *file_name, bool regular, bool *interdir_made) case ENOENT: /* Attempt creating missing intermediate directories. */ - if (make_directories (file_name)) - { - *interdir_made = true; - return RECOVER_OK; - } + if (make_directories (file_name, interdir_made) == 0 && *interdir_made) + return RECOVER_OK; break; default: @@ -776,7 +797,7 @@ extract_dir (char *file_name, int typeflag) for (;;) { - status = mkdir (file_name, mode); + status = mkdirat (chdir_fd, file_name, mode); if (status == 0) { current_mode = mode & ~ current_umask; @@ -863,6 +884,21 @@ open_output_file (char const *file_name, int typeflag, mode_t mode, } } + /* If O_NOFOLLOW is needed but does not work, check for a symlink + separately. There's a race condition, but that cannot be avoided + on hosts lacking O_NOFOLLOW. */ + if (! HAVE_WORKING_O_NOFOLLOW + && overwriting_old_files && ! dereference_option) + { + struct stat st; + if (fstatat (chdir_fd, file_name, &st, AT_SYMLINK_NOFOLLOW) == 0 + && S_ISLNK (st.st_mode)) + { + errno = ELOOP; + return -1; + } + } + fd = openat (chdir_fd, file_name, openflag, mode); if (0 <= fd) { @@ -963,7 +999,7 @@ extract_file (char *file_name, int typeflag) if (written > size) written = size; errno = 0; - count = full_write (fd, data_block->buffer, written); + count = blocking_write (fd, data_block->buffer, written); size -= written; set_next_block_after ((union block *) @@ -1049,7 +1085,7 @@ create_placeholder_file (char *file_name, bool is_symlink, bool *interdir_made) delayed_link_head = p; p->dev = st.st_dev; p->ino = st.st_ino; - p->ctime = get_stat_ctime (&st); + p->birthtime = get_stat_birthtime (&st); p->is_symlink = is_symlink; if (is_symlink) { @@ -1107,7 +1143,8 @@ extract_link (char *file_name, int typeflag) if (ds->change_dir == chdir_current && ds->dev == st1.st_dev && ds->ino == st1.st_ino - && timespec_cmp (ds->ctime, get_stat_ctime (&st1)) == 0) + && (timespec_cmp (ds->birthtime, get_stat_birthtime (&st1)) + == 0)) { struct string_list *p = xmalloc (offsetof (struct string_list, string) + strlen (file_name) + 1); @@ -1190,7 +1227,7 @@ static int extract_node (char *file_name, int typeflag) { bool interdir_made = false; - mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX + mode_t mode = (current_stat_info.stat.st_mode & (MODE_RWX | S_IFBLK | S_IFCHR) & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); while (mknodat (chdir_fd, file_name, mode, current_stat_info.stat.st_rdev) @@ -1473,7 +1510,7 @@ apply_delayed_links (void) if (fstatat (chdir_fd, source, &st, AT_SYMLINK_NOFOLLOW) == 0 && st.st_dev == ds->dev && st.st_ino == ds->ino - && timespec_cmp (get_stat_ctime (&st), ds->ctime) == 0) + && timespec_cmp (get_stat_birthtime (&st), ds->birthtime) == 0) { /* Unlink the placeholder, then create a hard link if possible, a symbolic link otherwise. */ @@ -1544,11 +1581,12 @@ rename_directory (char *src, char *dst) if (renameat (chdir_fd, src, chdir_fd, dst) != 0) { int e = errno; + bool interdir_made; switch (e) { case ENOENT: - if (make_directories (dst)) + if (make_directories (dst, &interdir_made) == 0) { if (renameat (chdir_fd, src, chdir_fd, dst) == 0) return true;