[Bug 1775] NFS issues: read/write problems when requested bytes greater than nfsStBlksize. Failure to create files and symlinks.

bugzilla-daemon at rtems.org bugzilla-daemon at rtems.org
Wed Jul 13 17:00:04 UTC 2011


https://www.rtems.org/bugzilla/show_bug.cgi?id=1775

strauman at slac.stanford.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.11                        |4.10
           Severity|normal                      |major

--- Comment #2 from strauman at slac.stanford.edu 2011-07-13 12:00:03 CDT ---
The first issue reported and fixed ("Correct usage of nfs_evalpath_arg in
nfs_do_evalpath()") is indeed a serious bug that should IMO be fixed on the
4.10 branch and the head (it was introduced by changes to the code after 4.9
IIRC).

However, the other issue (read/write count greater than nfsStBlksize) could not
be confirmed. The NFS layer is on top of RPC and may in principle use an
arbitrary
transfer size (the underlying protocol layers must handle this transparently).
However, NFS2 itself imposes a limit of 8192 bytes (payload; note that the
actual RPC is bigger than that).

If this was indeed a problem then it would be a bug in the lower protocols
(IP must handle fragmentation transparently).

Indeed, a loop of

while ( (got = read( nfs_in_fd, buffer, 10000 )) >0 )
    write( nfs_out_fd, buffer, got );

works as expected (regardless of the value of nfsStBlksize).

Hence, I'd suggest to remove the second and third hunk from the patch
(see new attachment).

-- 
Configure bugmail: https://www.rtems.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching all bug changes.



More information about the bugs mailing list