Hi Niels, On 2018/8/17 18:14, Niels de Vos wrote: > On Fri, Aug 17, 2018 at 05:22:17PM +0800, Kinglong Mee wrote: >> Hi Niels, >> >> On 2018/8/17 17:13, Niels de Vos wrote: >>> On Fri, Aug 17, 2018 at 03:04:43PM +0800, Kinglong Mee wrote: >>>> Hello folks, >>>> >>>> nfs-ganesha using the new gfapi named glfs_h_acl_set/glfs_h_acl_get, >>>> at xlator posix, glusterfsd calls acl_get_file/acl_set_file (libacl functions) to process xattrs. >>>> >>>> By default, sys_lsetxattr/sys_llistxattr/sys_lgetxattr/sys_lremovexattr are used to process xattrs. >>>> But, unfortunately, those two functions do syscall by getxattr/setxattr. >>>> I don't think that is we want. >>>> >>>> Is it a known problem ? >>> >>> There should not be a problem for libacl to use syscalls directly. The >>> Gluster sources use sys_<syscall> so that there can be wrappers for the >>> differences between OS's. In the end, these sys_<syscall> functions will >>> mostly call the <syscall> with (adapted) arguments. >>> >>> I do not know what problem you are facing, but I can imagine that there >>> is a 'getxattr' symbol in the executable image that gets called by >>> libacl, instead of the 'getxattr' syscall. This will likely result in >>> very strange behaviour, if not segfaults. >> >> Sorry for my unclear description. >> The real problem here is libacl gets/sets xattrs by getxattr/setxattr which follow symbolic links, >> but, posix xlator get/set xattrs by sys_l*xattr which do not follow symbolic links. > > Permission checking is done by the kernel. I do not think setting ACLs > on a symlink makes much sense. More liberal permissions on the symlink > will not help with accessing the contents, and restricting permissions > on a symlink still give the user to access the contents through its real > filename. > > Is there a reason that having ACLs on a symlink can have benefits? Sorry, i don't know. Md-cache supports caching GF_POSIX_ACL_ACCESS/GF_POSIX_ACL_DEFAULT right now, but posix_xattr_fill (call _posix_xattr_get_set) does not fill those two xattrs. After I adds the posix_pacl_get to _posix_xattr_get_set, there are some problems for symlink files. So that, I find the different between acl_get_file and sys_llistxattr/sys_lgetxattr. thanks, Kinglong Mee _______________________________________________ Gluster-devel mailing list Gluster-devel@xxxxxxxxxxx https://lists.gluster.org/mailman/listinfo/gluster-devel
