bug#78328: Copy fails setting system.nfs4_acl extended attribute [cp (GNU coreutils) 9.7.7-6218c]
Paul Eggert <[email protected]>
| Newsgroups | gmane.comp.gnu.core-utils.bugs |
|---|---|
| Organization | UCLA Computer Science Department |
| Message-ID | <[email protected]> |
On 2025-05-09 02:32, Pádraig Brady wrote: > This is actually being looked at in: > https://bugzilla.redhat.com/2363149 > > There is a proposed patch there. I looked at that patch, and although it sorta works it has a memory leak and it issues unnecessary system calls in the normal case. I wrote a more comprehensive patch and installed it into Gnulib; see attached (which combines two Gnulib patches). I've merged this into bleeding-edge Coreutils on Savannah so someone who builds from Git can simply do that to try it out. I hope that someone who can reproduce the bug can try this patch out. I didn't reproduce the bug on my RHEL 9.5 host with a NetApp NFS server, but NFS is kinda tricky that way.
gnulib.patch
(text/x-patch, 21 KB)
diff --git a/ChangeLog b/ChangeLog index 9cc1032a85..3d32510130 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,33 @@ +2025-05-09 Paul Eggert <[email protected]> + + acl-tests: link with $(FILE_HAS_ACL_LIB) + * modules/acl-tests (test_copy_acl_LDADD): Add + $(FILE_HAS_ACL_LIB), since qcopy-acl depends on file-has-acl. + Although this suggests that QCOPY_ACL_LIB should contain + FILE_HAS_ACL_LIB, I’m not sure whether that’s the right course of + action and anyway this is good enough for coreutils. + + qcopy-acl: port better to NFSv4 on GNU/Linux + Problem reported by Ian Dall in <https://bugs.gnu.org/78328> + and by Thomas Clark in <https://bugzilla.redhat.com/2363149>. + * lib/file-has-acl.c (smack_new_label_from_file) [!HAVE_SMACK]: + New dummy function. + (has_xattr, get_aclinfo): New arg FD. All callers changed. + Remove some unnecessary MAYBE_UNUSEDs. + (acl_get_fd_np): Fall back on acl_get_fd if this function is + needed but not available. + (acl_get_fdfile): New function, if needed. + (file_has_aclinfo): Reimplement in terms of ... + (fdfile_has_aclinfo): ... this new function, + which also has an FD argument. + * lib/qcopy-acl.c [USE_XATTR]: Include dirent.h, for DT_DIR etc. + (qcopy_acl): If attr_copy_file or attr_copy_fd fail with EOPNOTSUPP, + don’t fail if the source has a trivial ACL (this is the part + that fixes the bug; the rest is optimization). + * modules/qcopy-acl (Depends-on): Depend on dirent-h and + file-has-acl if $use_xattr. Also, depend on acl-permissions + unconditionally, since qcopy-acl.c includes acl.h unconditionally. + 2025-05-08 Bruno Haible <[email protected]> nstrftime: Fix a link error on Android API level ≥ 35. diff --git a/NEWS b/NEWS index 57249ffc02..639760a5b9 100644 --- a/NEWS +++ b/NEWS @@ -74,6 +74,10 @@ User visible incompatible changes Date Modules Changes +2025-05-09 copy-acl The mode_t arguments of qcopy_acl and xcopy_acl + qcopy-acl should be the full st_mode of the source, + not merely st_mode's permission bits. + 2025-04-29 hash-triple-simple This module is renamed to hashcode-named-file. 2025-01-02 string-desc The function prefix is changed from string_desc_ diff --git a/lib/acl.h b/lib/acl.h index 90fd24e152..e3c134fb41 100644 --- a/lib/acl.h +++ b/lib/acl.h @@ -79,6 +79,8 @@ struct aclinfo bool acl_errno_valid (int) _GL_ATTRIBUTE_CONST; int file_has_acl (char const *, struct stat const *); int file_has_aclinfo (char const *restrict, struct aclinfo *restrict, int); +int fdfile_has_aclinfo (int, char const *restrict, + struct aclinfo *restrict, int); #if HAVE_LINUX_XATTR_H && HAVE_LISTXATTR bool aclinfo_has_xattr (struct aclinfo const *, char const *) diff --git a/lib/copy-acl.c b/lib/copy-acl.c index c36f64e51d..2fce6c7d46 100644 --- a/lib/copy-acl.c +++ b/lib/copy-acl.c @@ -33,6 +33,7 @@ a valid file descriptor, use file descriptor operations, else use filename based operations on SRC_NAME. Likewise for DEST_DESC and DST_NAME. + MODE should be the source file's st_mode. If access control lists are not available, fchmod the target file to MODE. Also sets the non-permission bits of the destination file (S_ISUID, S_ISGID, S_ISVTX) to those from MODE if any are set. diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c index 66b920c1ab..a356ee0d0b 100644 --- a/lib/file-has-acl.c +++ b/lib/file-has-acl.c @@ -85,6 +85,13 @@ smack_new_label_from_path (MAYBE_UNUSED const char *path, { return -1; } +static ssize_t +smack_new_label_from_file (MAYBE_UNUSED int fd, + MAYBE_UNUSED const char *xattr, + MAYBE_UNUSED char **label) +{ + return -1; +} # endif static bool is_smack_enabled (void) @@ -115,14 +122,16 @@ aclinfo_may_indicate_xattr (struct aclinfo const *ai) static bool has_xattr (char const *xattr, struct aclinfo const *ai, - MAYBE_UNUSED char const *restrict name, MAYBE_UNUSED int flags) + int fd, char const *restrict name, int flags) { if (ai && aclinfo_has_xattr (ai, xattr)) return true; else if (!ai || aclinfo_may_indicate_xattr (ai)) { - int ret = ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr) - (name, xattr, NULL, 0)); + int ret = (fd < 0 + ? ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr) + (name, xattr, NULL, 0)) + : fgetxattr (fd, xattr, NULL, 0)); if (0 <= ret || (errno == ERANGE || errno == E2BIG)) return true; } @@ -145,11 +154,12 @@ aclinfo_has_xattr (struct aclinfo const *ai, char const *xattr) return false; } -/* Get attributes of the file NAME into AI, if USE_ACL. +/* Get attributes of the file FD aka NAME into AI, if USE_ACL. + Ignore FD if it is negative. If FLAGS & ACL_GET_SCONTEXT, also get security context. If FLAGS & ACL_SYMLINK_FOLLOW, follow symbolic links. */ static void -get_aclinfo (char const *name, struct aclinfo *ai, int flags) +get_aclinfo (int fd, char const *name, struct aclinfo *ai, int flags) { int scontext_err = ENOTSUP; ai->buf = ai->u.__gl_acl_ch; @@ -163,7 +173,9 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags) = (flags & ACL_SYMLINK_FOLLOW ? listxattr : llistxattr); while (true) { - ai->size = lsxattr (name, ai->buf, acl_alloc); + ai->size = (fd < 0 + ? lsxattr (name, ai->buf, acl_alloc) + : flistxattr (fd, ai->buf, acl_alloc)); if (0 < ai->size) break; ai->u.err = ai->size < 0 ? errno : 0; @@ -171,7 +183,9 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags) break; /* The buffer was too small. Find how large it should have been. */ - ssize_t size = lsxattr (name, NULL, 0); + ssize_t size = (fd < 0 + ? lsxattr (name, NULL, 0) + : flistxattr (fd, NULL, 0)); if (size <= 0) { ai->size = size; @@ -214,9 +228,13 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags) { if (ai->size < 0 || aclinfo_has_xattr (ai, XATTR_NAME_SMACK)) { - ssize_t r = smack_new_label_from_path (name, "security.SMACK64", - flags & ACL_SYMLINK_FOLLOW, - &ai->scontext); + static char const SMACK64[] = "security.SMACK64"; + ssize_t r = + (fd < 0 + ? smack_new_label_from_path (name, SMACK64, + flags & ACL_SYMLINK_FOLLOW, + &ai->scontext) + : smack_new_label_from_file (fd, SMACK64, &ai->scontext)); scontext_err = r < 0 ? errno : 0; } } @@ -226,8 +244,10 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags) if (ai->size < 0 || aclinfo_has_xattr (ai, XATTR_NAME_SELINUX)) { ssize_t r = - ((flags & ACL_SYMLINK_FOLLOW ? getfilecon : lgetfilecon) - (name, &ai->scontext)); + (fd < 0 + ? ((flags & ACL_SYMLINK_FOLLOW ? getfilecon : lgetfilecon) + (name, &ai->scontext)) + : fgetfilecon (fd, &ai->scontext)); scontext_err = r < 0 ? errno : 0; # ifndef SE_SELINUX_INLINE /* Gnulib's selinux-h module is not in use, so getfilecon and @@ -362,11 +382,13 @@ acl_nfs4_nontrivial (uint32_t *xattr, ssize_t nbytes) } #endif -#if (!USE_LINUX_XATTR && USE_ACL && HAVE_ACL_GET_FD \ - && !HAVE_ACL_EXTENDED_FILE && !HAVE_ACL_TYPE_EXTENDED \ - && !HAVE_ACL_GET_LINK_NP) -# include <fcntl.h> -# ifdef O_PATH +#if (!USE_LINUX_XATTR && USE_ACL && !HAVE_ACL_EXTENDED_FILE \ + && !HAVE_ACL_TYPE_EXTENDED) + +# if HAVE_ACL_GET_FD && !HAVE_ACL_GET_LINK_NP +# include <fcntl.h> +# ifdef O_PATH +# define acl_get_fd_np(fd, type) acl_get_fd (fd) /* Like acl_get_file, but do not follow symbolic links. */ static acl_t @@ -381,8 +403,24 @@ acl_get_link_np (char const *name, acl_type_t type) errno = err; return r; } -# define HAVE_ACL_GET_LINK_NP 1 +# define HAVE_ACL_GET_LINK_NP 1 +# endif # endif + +static acl_t +acl_get_fdfile (int fd, char const *name, acl_type_t type, int flags) +{ + acl_t (*get) (char const *, acl_type_t) = acl_get_file; +# if HAVE_ACL_GET_LINK_NP /* FreeBSD, NetBSD >= 10, Cygwin >= 2.5 */ + if (0 <= fd) + return acl_get_fd_np (fd, type); + if (! (flags & ACL_SYMLINK_FOLLOW)) + get = acl_get_link_np; +# else + /* Ignore FD and FLAGS, unfortunately. */ +# endif + return get (name, type); +} #endif /* Return 1 if NAME has a nontrivial access control list, @@ -398,14 +436,35 @@ acl_get_link_np (char const *name, acl_type_t type) If the d_type value is not known, use DT_UNKNOWN though this may be less efficient. */ int -file_has_aclinfo (MAYBE_UNUSED char const *restrict name, +file_has_aclinfo (char const *restrict name, struct aclinfo *restrict ai, int flags) +{ + return fdfile_has_aclinfo (-1, name, ai, flags); +} + +/* Return 1 if FD aka NAME has a nontrivial access control list, + 0 if ACLs are not supported, or if NAME has no or only a base ACL, + and -1 (setting errno) on error. Note callers can determine + if ACLs are not supported as errno is set in that case also. + Ignore FD if it is negative. + Set *AI to ACL info regardless of return value. + FLAGS should be a <dirent.h> d_type value, optionally ORed with + - _GL_DT_NOTDIR if it is known that NAME is not a directory, + - ACL_GET_SCONTEXT to retrieve security context and return 1 if present, + - ACL_SYMLINK_FOLLOW to follow the link if NAME is a symbolic link; + otherwise do not follow them if possible. + If the d_type value is not known, use DT_UNKNOWN though this may be less + efficient. */ +int +fdfile_has_aclinfo (MAYBE_UNUSED int fd, + MAYBE_UNUSED char const *restrict name, + struct aclinfo *restrict ai, int flags) { MAYBE_UNUSED unsigned char d_type = flags & UCHAR_MAX; #if USE_LINUX_XATTR int initial_errno = errno; - get_aclinfo (name, ai, flags); + get_aclinfo (fd, name, ai, flags); if (!aclinfo_may_indicate_xattr (ai) && ai->size <= 0) { @@ -418,11 +477,11 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, In earlier Fedora the two types of ACLs were mutually exclusive. Attempt to work correctly on both kinds of systems. */ - if (!has_xattr (XATTR_NAME_NFSV4_ACL, ai, name, flags)) + if (!has_xattr (XATTR_NAME_NFSV4_ACL, ai, fd, name, flags)) return - (has_xattr (XATTR_NAME_POSIX_ACL_ACCESS, ai, name, flags) + (has_xattr (XATTR_NAME_POSIX_ACL_ACCESS, ai, fd, name, flags) || ((d_type == DT_DIR || d_type == DT_UNKNOWN) - && has_xattr (XATTR_NAME_POSIX_ACL_DEFAULT, ai, name, flags))); + && has_xattr (XATTR_NAME_POSIX_ACL_DEFAULT, ai, fd, name, flags))); /* A buffer large enough to hold any trivial NFSv4 ACL. The max length of a trivial NFSv4 ACL is 6 words for owner, @@ -432,8 +491,10 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, everyone is another word to hold "EVERYONE@". */ uint32_t buf[2 * (6 + 6 + 7)]; - int ret = ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr) - (name, XATTR_NAME_NFSV4_ACL, buf, sizeof buf)); + int ret = (fd < 0 + ? ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr) + (name, XATTR_NAME_NFSV4_ACL, buf, sizeof buf)) + : fgetxattr (fd, XATTR_NAME_NFSV4_ACL, buf, sizeof buf)); if (ret < 0) switch (errno) { @@ -467,20 +528,23 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, /* On Linux, acl_extended_file is an optimized function: It only makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for ACL_TYPE_DEFAULT. */ - ret = ((flags & ACL_SYMLINK_FOLLOW - ? acl_extended_file - : acl_extended_file_nofollow) - (name)); + ret = (fd < 0 + ? ((flags & ACL_SYMLINK_FOLLOW + ? acl_extended_file + : acl_extended_file_nofollow) + (name)) + : acl_extended_fd (fd)); # elif HAVE_ACL_TYPE_EXTENDED /* Mac OS X */ /* On Mac OS X, acl_get_file (name, ACL_TYPE_ACCESS) and acl_get_file (name, ACL_TYPE_DEFAULT) always return NULL / EINVAL. There is no point in making these two useless calls. The real ACL is retrieved through - acl_get_file (name, ACL_TYPE_EXTENDED). */ - acl_t acl = ((flags & ACL_SYMLINK_FOLLOW - ? acl_get_file - : acl_get_link_np) - (name, ACL_TYPE_EXTENDED)); + ACL_TYPE_EXTENDED. */ + acl_t acl = + (fd < 0 + ? ((flags & ACL_SYMLINK_FOLLOW ? acl_get_file : acl_get_link_np) + (name, ACL_TYPE_EXTENDED)) + : acl_get_fd_np (fd, ACL_TYPE_EXTENDED)); if (acl) { ret = acl_extended_nontrivial (acl); @@ -489,13 +553,8 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, else ret = -1; # else /* FreeBSD, NetBSD >= 10, IRIX, Tru64, Cygwin >= 2.5 */ - acl_t (*acl_get_file_or_link) (char const *, acl_type_t) = acl_get_file; -# if HAVE_ACL_GET_LINK_NP /* FreeBSD, NetBSD >= 10, Cygwin >= 2.5 */ - if (! (flags & ACL_SYMLINK_FOLLOW)) - acl_get_file_or_link = acl_get_link_np; -# endif - acl_t acl = acl_get_file_or_link (name, ACL_TYPE_ACCESS); + acl_t acl = acl_get_fdfile (fd, name, ACL_TYPE_ACCESS, flags); if (acl) { ret = acl_access_nontrivial (acl); @@ -517,7 +576,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, && (d_type == DT_DIR || (d_type == DT_UNKNOWN && !(flags & _GL_DT_NOTDIR)))) { - acl = acl_get_file_or_link (name, ACL_TYPE_DEFAULT); + acl = acl_get_fdfile (fd, name, ACL_TYPE_DEFAULT, flags); if (acl) { # ifdef __CYGWIN__ /* Cygwin >= 2.5 */ @@ -562,7 +621,10 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, /* Solaris 10 (newer version), which has additional API declared in <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial, - acl_fromtext, ...). */ + acl_fromtext, ...). + + Ignore FD, unfortunately. That is better than mishandling + ZFS-style ACLs, as the general case code does. */ return acl_trivial (name); # else /* Solaris, Cygwin, general case */ @@ -586,7 +648,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, for (;;) { - count = acl (name, GETACL, alloc, entries); + count = (fd < 0 + ? acl (name, GETACL, alloc, entries) + : facl (fd, GETACL, alloc, entries)); if (count < 0 && errno == ENOSPC) { /* Increase the size of the buffer. */ @@ -657,7 +721,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, for (;;) { - count = acl (name, ACE_GETACL, alloc, entries); + count = (fd < 0 + ? acl (name, ACE_GETACL, alloc, entries) + : facl (fd, ACE_GETACL, alloc, entries)); if (count < 0 && errno == ENOSPC) { /* Increase the size of the buffer. */ @@ -722,7 +788,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, struct acl_entry entries[NACLENTRIES]; int count; - count = getacl (name, NACLENTRIES, entries); + count = (fd < 0 + ? getacl (name, NACLENTRIES, entries) + : fgetacl (fd, NACLENTRIES, entries)); if (count < 0) { @@ -751,7 +819,8 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, { struct stat statbuf; - if (stat (name, &statbuf) == -1 && errno != EOVERFLOW) + if ((fd < 0 ? stat (name, &statbuf) : fstat (fd, &statbuf)) < 0 + && errno != EOVERFLOW) return -1; return acl_nontrivial (count, entries); @@ -765,6 +834,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, struct acl entries[NACLVENTRIES]; int count; + /* Ignore FD, unfortunately. */ count = acl ((char *) name, ACL_GET, NACLVENTRIES, entries); if (count < 0) @@ -809,7 +879,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, /* The docs say that type being 0 is equivalent to ACL_ANY, but it is not true, in AIX 5.3. */ type.u64 = ACL_ANY; - if (aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) >= 0) + if (0 <= (fd < 0 + ? aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) + : aclx_fget (fd, 0, &type, aclbuf, &aclsize, &mode))) break; if (errno == ENOSYS) return 0; @@ -855,7 +927,10 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, union { struct acl a; char room[4096]; } u; - if (statacl ((char *) name, STX_NORMAL, &u.a, sizeof (u)) < 0) + if ((fd < 0 + ? statacl ((char *) name, STX_NORMAL, &u.a, sizeof u) + : fstatacl (fd, STX_NORMAL, &u.a, sizeof u)) + < 0) return -1; return acl_nontrivial (&u.a); @@ -866,6 +941,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name, struct acl entries[NACLENTRIES]; int count; + /* Ignore FD, unfortunately. */ count = acl ((char *) name, ACL_GET, NACLENTRIES, entries); if (count < 0) diff --git a/lib/qcopy-acl.c b/lib/qcopy-acl.c index ad7966152a..282f4b2d2a 100644 --- a/lib/qcopy-acl.c +++ b/lib/qcopy-acl.c @@ -26,6 +26,7 @@ #if USE_XATTR # include <attr/libattr.h> +# include <dirent.h> # include <string.h> # if HAVE_LINUX_XATTR_H @@ -61,6 +62,7 @@ is_attr_permissions (const char *name, struct error_context *ctx) a valid file descriptor, use file descriptor operations, else use filename based operations on SRC_NAME. Likewise for DEST_DESC and DST_NAME. + MODE should be the source file's st_mode. If access control lists are not available, fchmod the target file to MODE. Also sets the non-permission bits of the destination file (S_ISUID, S_ISGID, S_ISVTX) to those from MODE if any are set. @@ -86,10 +88,29 @@ qcopy_acl (const char *src_name, int source_desc, const char *dst_name, Functions attr_copy_* return 0 in case we copied something OR nothing to copy */ if (ret == 0) - ret = source_desc <= 0 || dest_desc <= 0 - ? attr_copy_file (src_name, dst_name, is_attr_permissions, NULL) - : attr_copy_fd (src_name, source_desc, dst_name, dest_desc, - is_attr_permissions, NULL); + { + ret = source_desc <= 0 || dest_desc <= 0 + ? attr_copy_file (src_name, dst_name, is_attr_permissions, NULL) + : attr_copy_fd (src_name, source_desc, dst_name, dest_desc, + is_attr_permissions, NULL); + + /* Copying can fail with EOPNOTSUPP even when the source + permissions are trivial (Bug#78328). Don't report an error + in this case, as the chmod_or_fchmod suffices. */ + if (ret < 0 && errno == EOPNOTSUPP) + { + /* fdfile_has_aclinfo cares only about DT_DIR, _GL_DT_NOTDIR, + and DT_LNK (but DT_LNK is not possible here), + so use _GL_DT_NOTDIR | DT_UNKNOWN for other file types. */ + int flags = S_ISDIR (mode) ? DT_DIR : _GL_DT_NOTDIR | DT_UNKNOWN; + + struct aclinfo ai; + if (!fdfile_has_aclinfo (source_desc, src_name, &ai, flags)) + ret = 0; + aclinfo_free (&ai); + errno = EOPNOTSUPP; + } + } #else /* no XATTR, so we proceed the old dusty way */ struct permission_context ctx; diff --git a/modules/acl-tests b/modules/acl-tests index 5add9405bc..c77ca16361 100644 --- a/modules/acl-tests +++ b/modules/acl-tests @@ -26,5 +26,5 @@ TESTS += \ TESTS_ENVIRONMENT += USE_ACL=$(USE_ACL) check_PROGRAMS += test-set-mode-acl test-copy-acl test-sameacls test_set_mode_acl_LDADD = $(LDADD) $(LIB_ACL) $(LIBUNISTRING) @LIBINTL@ $(MBRTOWC_LIB) $(LIBC32CONV) -test_copy_acl_LDADD = $(LDADD) $(LIB_ACL) $(QCOPY_ACL_LIB) $(LIBUNISTRING) @LIBINTL@ $(MBRTOWC_LIB) $(LIBC32CONV) +test_copy_acl_LDADD = $(LDADD) $(LIB_ACL) $(QCOPY_ACL_LIB) $(FILE_HAS_ACL_LIB) $(LIBUNISTRING) @LIBINTL@ $(MBRTOWC_LIB) $(LIBC32CONV) test_sameacls_LDADD = $(LDADD) $(LIB_ACL) @LIBINTL@ $(MBRTOWC_LIB) diff --git a/modules/qcopy-acl b/modules/qcopy-acl index e692a28625..8adedf7ad9 100644 --- a/modules/qcopy-acl +++ b/modules/qcopy-acl @@ -7,7 +7,9 @@ m4/acl.m4 m4/xattr.m4 Depends-on: -acl-permissions [test "$use_xattr" != yes] +acl-permissions +dirent-h [test "$use_xattr" = yes] +file-has-acl [test "$use_xattr" = yes] configure.ac: gl_QCOPY_ACL