xattr API question

[Andreas Jaeger <aj@xxxxxxx>]

Hi,

I'm one of the glibc developers and we considered adding support for
the *xattr syscalls to glibc.

Ulrich Drepper mentioned:
> - the various *xattr syscalls which were introduced in the 2.5 kernel
> might need libc support.  I guess they do.  But somebody should contact
> whoever wrote the code and ask them about the API which should be
> provided.

Can you tell me a bit more about the API?  Is it stable?  Should we
define it in glibc?  Which constants/flags should be added?  Do you
have some more documentation for the interface?  Is it used in other
OSes and which header files define all the stuff?

I guess, we have these interfaces to implement and at least briefly
document:

setxattr(char *path, char *name, void *value, size_t size, int flags);
lsetxattr(char *path, char *name, void *value, size_t size, int flags);
fsetxattr(int fd, char *name, void *value, size_t size, int flags)
getxattr(char *path, char *name, void *value, size_t size)
lgetxattr(char *path, char *name, void *value, size_t size)
fgetxattr(int fd, char *name, void *value, size_t size)
listxattr(char *path, char *list, size_t size)
llistxattr(char *path, char *list, size_t size)
flistxattr(int fd, char *list, size_t size)
removexattr(char *path, char *name)
lremovexattr(char *path, char *name)
fremovexattr(int fd, char *name)

Some questions: What's the meaning of the size parameter?  What can be
given for flags?  What does getxattr return?

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@xxxxxxx
   private aj@xxxxxxxxxxxxxx
    http://www.suse.de/~aj