ä 2010å12æ21æ 22:40, Eric Blake åé:
On 12/20/2010 11:47 PM, Osier Yang wrote:
a more efficient solution would be to check if errno
is ELOOP or ENOENT (the only possibilities for a dangling symlink; any
other error should return -1), and in those two cases a successful
lstat() is sufficient to detect a broken symlink without resorting to
reading its contents.
I guess you mean stat, lstat will not work here, as it doesn't follow
the *symbolic* link. what we need to do is to determine if the symbolic
link is dangling, so use "stat" to update the patch, v3 send, thanks
again.
No, I really meant lstat(). If stat() would have failed because of a
dangling symlink, then open() will fail for the same reasons.
Therefore, check errno before lstat, and use the successful lstat as
proof that a symlink is in place but that stat()ing the symlink would
fail because it is dangling.
if (open(f)< 0) {
if ((errno == ENOENT || errno == ELOOP)&&
lstat(f, buf) == 0) {
/* Dangling symlink, since lstat() passed but open failed. */
log message about ignored file
return -2;
}
either an unrelated errno, like EACCES, or we got ENOENT because
the file was deleted after readdir but before open/lstat
error message about unaccessible file
return -1;
}
Eric, thanks for the detailed knowledge..
- Osier
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list