On 01/31 2014 18:44 PM, Vyacheslav Dubeyko wrote: > On Fri, 2014-01-31 at 16:54 +0800, Jeff Liu wrote: >> Hello, >> >> On 01/31 2014 15:40 PM, Sun_Blood wrote: >>> Hello, >>> >>> If I understands it correctly XFS don't have a limit to the size of >>> extended attributes(EA) but Linux impose a limit at 64k. >>> What I am trying to do is build a backup server that our Apple computers >>> will use together with rsync to backup files to. The problem I face is >>> that Apple HFS+ don't have a limit to EA so it has files with more then >>> 64k of EA in it. > > Technical Note TN1150: > "In an HFS Plus B-tree, the node size is determined by a field > (nodeSize) in the header node. The node size must be a power from 512 > through 32,768." > > So, as minimum, xattrs unable to be a larger than node size. > > But xattrs' size has limitation anyway: > > https://github.com/darwin-on-arm/xnu/blob/master/bsd/hfs/hfs.h#L849 > > /* Maximum extended attribute size supported for all extended attributes except > * resource fork and finder info. > */ > #define HFS_XATTR_MAXSIZE (128 * 1024) > > So, I need to check and correct slightly HFS+ xattrs support code. > Because, I used 3082 bytes limitation value. I just verified above limits on Mac OS X, that's true. sh-3.2# a=`perl -e 'print "A"x131072'` sh-3.2# xattr -w user.comment ${a} xattr_test sh-3.2# a=`perl -e 'print "A"x131073'` sh-3.2# xattr -w user.comment ${a} xattr_test xattr: [Errno 7] Argument list too long: 'xattr' Hence, that would be a problem to preserve EA with large value size on Linux. Thanks, -Jeff _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
