/* 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;
}
}
+/* Return true if A and B are the same birthtimes.
+ Unavailable birthtimes, which have negative tv_nsec members,
+ all compare equal to each other. */
+static bool
+same_birthtime (struct timespec a, struct timespec b)
+{
+ return (a.tv_nsec == b.tv_nsec && (a.tv_nsec < 0 || a.tv_sec == b.tv_sec));
+}
+
/* Check time after successfully setting FILE_NAME's time stamp to T. */
static void
check_time (char const *file_name, struct timespec t)
struct stat st;
h->after_links = 1;
- if (fstatat (chdir_fd, h->file_name, &st, 0) != 0)
+ if (deref_stat (h->file_name, &st) != 0)
stat_error (h->file_name);
else
{
/* 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;
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
- <Warren.Hyde@motorola.com> */
- || 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
+ directory, and has a time stamp newer than (or equal to) that of
+ TAR_STAT. */
static bool
-file_newer_p (const char *file_name, struct tar_stat_info *tar_stat)
+file_newer_p (const char *file_name, struct stat const *stp,
+ struct tar_stat_info *tar_stat)
{
struct stat st;
- if (fstatat (chdir_fd, file_name, &st, 0))
+ if (!stp)
{
- if (errno != ENOENT)
+ if (deref_stat (file_name, &st) != 0)
{
- stat_warn (file_name);
- /* Be on the safe side: if the file does exist assume it is newer */
- return true;
+ if (errno != ENOENT)
+ {
+ stat_warn (file_name);
+ /* Be safer: if the file exists, assume it is newer. */
+ return true;
+ }
+ return false;
}
- return false;
- }
- if (!S_ISDIR (st.st_mode)
- && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (&st)) <= 0)
- {
- return true;
+ stp = &st;
}
- return false;
+
+ return (! S_ISDIR (stp->st_mode)
+ && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (stp)) <= 0);
}
#define RECOVER_NO 0
Return RECOVER_OK if we somewhat increased our chances at a successful
extraction, RECOVER_NO if there are no chances, and RECOVER_SKIP if the
caller should skip extraction of that member. The value of errno is
- properly restored on returning RECOVER_NO. */
+ properly restored on returning RECOVER_NO.
+
+ If REGULAR, the caller was trying to extract onto a regular file.
+
+ Set *INTERDIR_MADE if an intermediate directory is made as part of
+ the recovery process. */
static int
-maybe_recoverable (char *file_name, bool *interdir_made)
+maybe_recoverable (char *file_name, bool regular, bool *interdir_made)
{
int e = errno;
+ struct stat st;
+ struct stat const *stp = 0;
if (*interdir_made)
return RECOVER_NO;
- switch (errno)
+ 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 <http://gnats.netbsd.org/43154>. */
+ 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;
+ if (strchr (file_name, '/'))
+ {
+ if (deref_stat (file_name, &st) != 0)
+ break;
+ stp = &st;
+ }
+
+ /* The caller tried to open a symbolic link with O_NOFOLLOW.
+ Fall through, treating it as an already-existing file. */
+
case EEXIST:
/* Remove an old file, if the options allow this. */
return RECOVER_SKIP;
case KEEP_NEWER_FILES:
- if (file_newer_p (file_name, ¤t_stat_info))
- {
- errno = e;
- return RECOVER_NO;
- }
+ if (file_newer_p (file_name, stp, ¤t_stat_info))
+ break;
/* FALL THROUGH */
case DEFAULT_OLD_FILES:
case NO_OVERWRITE_DIR_OLD_FILES:
case OVERWRITE_OLD_FILES:
- {
- int r = remove_any_file (file_name, ORDINARY_REMOVE_OPTION);
- errno = EEXIST;
- return r > 0 ? RECOVER_OK : RECOVER_NO;
- }
+ if (0 < remove_any_file (file_name, ORDINARY_REMOVE_OPTION))
+ return RECOVER_OK;
+ break;
case UNLINK_FIRST_OLD_FILES:
break;
case ENOENT:
/* Attempt creating missing intermediate directories. */
- if (! make_directories (file_name))
- {
- errno = ENOENT;
- return RECOVER_NO;
- }
- *interdir_made = true;
- return RECOVER_OK;
+ if (make_directories (file_name, interdir_made) == 0 && *interdir_made)
+ return RECOVER_OK;
+ break;
default:
/* Just say we can't do anything about it... */
-
- return RECOVER_NO;
+ break;
}
+
+ errno = e;
+ return RECOVER_NO;
}
/* Fix the statuses of all directories whose statuses need fixing, and
for (;;)
{
- status = mkdir (file_name, mode);
+ status = mkdirat (chdir_fd, file_name, mode);
if (status == 0)
{
current_mode = mode & ~ current_umask;
|| old_files_option == OVERWRITE_OLD_FILES))
{
struct stat st;
- if (fstatat (chdir_fd, file_name, &st, 0) == 0)
+ if (deref_stat (file_name, &st) == 0)
{
current_mode = st.st_mode;
current_mode_mask = ALL_MODE_BITS;
errno = EEXIST;
}
- switch (maybe_recoverable (file_name, &interdir_made))
+ switch (maybe_recoverable (file_name, false, &interdir_made))
{
case RECOVER_OK:
continue;
{
int fd;
bool overwriting_old_files = old_files_option == OVERWRITE_OLD_FILES;
- int openflag = (O_WRONLY | O_BINARY | O_CREAT
- | (overwriting_old_files ? O_TRUNC : O_EXCL));
+ int openflag = (O_WRONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK
+ | O_CREAT
+ | (overwriting_old_files
+ ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW)
+ : O_EXCL));
if (typeflag == CONTTYPE)
{
}
}
+ /* 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 (! 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)
{
}
else
{
- int recover = RECOVER_NO;
- do
- fd = open_output_file (file_name, typeflag, mode,
- ¤t_mode, ¤t_mode_mask);
- while (fd < 0
- && (recover = maybe_recoverable (file_name, &interdir_made))
- == RECOVER_OK);
-
- if (fd < 0)
+ while ((fd = open_output_file (file_name, typeflag, mode,
+ ¤t_mode, ¤t_mode_mask))
+ < 0)
{
- skip_member ();
- if (recover == RECOVER_SKIP)
- return 0;
- open_error (file_name);
- return 1;
+ int recover = maybe_recoverable (file_name, true, &interdir_made);
+ if (recover != RECOVER_OK)
+ {
+ skip_member ();
+ if (recover == RECOVER_SKIP)
+ return 0;
+ open_error (file_name);
+ return 1;
+ }
}
}
while ((fd = openat (chdir_fd, file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0)
{
- switch (maybe_recoverable (file_name, interdir_made))
+ switch (maybe_recoverable (file_name, false, interdir_made))
{
case RECOVER_OK:
continue;
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)
{
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)
+ && same_birthtime (ds->birthtime, get_stat_birthtime (&st1)))
{
struct string_list *p = xmalloc (offsetof (struct string_list, string)
+ strlen (file_name) + 1);
errno = e;
}
- while ((rc = maybe_recoverable (file_name, &interdir_made)) == RECOVER_OK);
+ while ((rc = maybe_recoverable (file_name, false, &interdir_made))
+ == RECOVER_OK);
if (rc == RECOVER_SKIP)
return 0;
return create_placeholder_file (file_name, true, &interdir_made);
while (symlinkat (current_stat_info.link_name, chdir_fd, file_name) != 0)
- switch (maybe_recoverable (file_name, &interdir_made))
+ switch (maybe_recoverable (file_name, false, &interdir_made))
{
case RECOVER_OK:
continue;
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)
!= 0)
- switch (maybe_recoverable (file_name, &interdir_made))
+ switch (maybe_recoverable (file_name, false, &interdir_made))
{
case RECOVER_OK:
continue;
& ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
while (mkfifoat (chdir_fd, file_name, mode) != 0)
- switch (maybe_recoverable (file_name, &interdir_made))
+ switch (maybe_recoverable (file_name, false, &interdir_made))
{
case RECOVER_OK:
continue;
break;
case KEEP_NEWER_FILES:
- if (file_newer_p (file_name, ¤t_stat_info))
+ if (file_newer_p (file_name, 0, ¤t_stat_info))
{
WARNOPT (WARN_IGNORE_NEWER,
(0, 0, _("Current %s is newer or same age"),
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)
+ && same_birthtime (get_stat_birthtime (&st), ds->birthtime))
{
/* Unlink the placeholder, then create a hard link if possible,
a symbolic link otherwise. */
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;
projects / chaz / tar / blobdiff