diff options
Diffstat (limited to 'ports/unix/guts/fchmodat.c')
-rw-r--r-- | ports/unix/guts/fchmodat.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/ports/unix/guts/fchmodat.c b/ports/unix/guts/fchmodat.c index 59a92ce..69a953c 100644 --- a/ports/unix/guts/fchmodat.c +++ b/ports/unix/guts/fchmodat.c @@ -8,6 +8,7 @@ */ PSEUDO_STATBUF buf; int save_errno = errno; + static int picky_fchmodat = 0; #ifdef PSEUDO_NO_REAL_AT_FUNCTIONS if (dirfd != AT_FDCWD) { @@ -15,6 +16,16 @@ return -1; } if (flags & AT_SYMLINK_NOFOLLOW) { + /* Linux, as of this writing, will always reject this. + * GNU tar relies on getting the rejection. To cut down + * on traffic, we check for the failure, and if we saw + * a failure previously, we reject it right away and tell + * the caller to retry. + */ + if (picky_fchmodat) { + errno = ENOTSUP; + return -1; + } rc = base_lstat(path, &buf); } else { rc = base_stat(path, &buf); @@ -50,13 +61,22 @@ /* user bits added so "root" can always access files. */ #ifdef PSEUDO_NO_REAL_AT_FUNCTIONS - /* note: if path was a symlink, and AT_NOFOLLOW_SYMLINKS was + /* note: if path was a symlink, and AT_SYMLINK_NOFOLLOW was * specified, we already bailed previously. */ real_chmod(path, PSEUDO_FS_MODE(mode, S_ISDIR(buf.st_mode))); #else - real_fchmodat(dirfd, path, PSEUDO_FS_MODE(mode, S_ISDIR(buf.st_mode)), flags); + rc = real_fchmodat(dirfd, path, PSEUDO_FS_MODE(mode, S_ISDIR(buf.st_mode)), flags); + /* AT_SYMLINK_NOFOLLOW isn't supported by fchmodat. GNU tar + * tries to use it anyway, figuring it can just retry if that + * fails. So we want to report that *particular* failure instead + * of doing the fallback. + */ + if (rc == -1 && errno == ENOTSUP && (flags & AT_SYMLINK_NOFOLLOW)) { + picky_fchmodat = 1; + return -1; + } #endif - /* we ignore a failure from underlying fchmod, because pseudo + /* we otherwise ignore failures from underlying fchmod, because pseudo * may believe you are permitted to change modes that the filesystem * doesn't. Note that we also don't need to know whether the * file might be a (pseudo) block device or some such; pseudo |