cd123012d9
When the kernel calls svc_reserve to downsize the expected size of an RPC reply, it fails to account for the possibility of a checksum at the end of the packet. If a client mounts a NFSv2/3 with sec=krb5i/p, and does I/O then you'll generally see messages similar to this in the server's ring buffer: RPC request reserved 164 but used 208 While I was never able to verify it, I suspect that this problem is also the root cause of some oopses I've seen under these conditions: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=227726 This is probably also a problem for other sec= types and for NFSv4. The large reserved size for NFSv4 compound packets seems to generally paper over the problem, however. This patch adds a wrapper for svc_reserve that accounts for the possibility of a checksum. It also fixes up the appropriate callers of svc_reserve to call the wrapper. For now, it just uses a hardcoded value that I determined via testing. That value may need to be revised upward as things change, or we may want to eventually add a new auth_op that attempts to calculate this somehow. Unfortunately, there doesn't seem to be a good way to reliably determine the expected checksum length prior to actually calculating it, particularly with schemes like spkm3. Signed-off-by: Jeff Layton <jlayton@redhat.com> Acked-by: Neil Brown <neilb@suse.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Acked-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| Kbuild | ||
| auth.h | ||
| auth_gss.h | ||
| cache.h | ||
| clnt.h | ||
| debug.h | ||
| gss_api.h | ||
| gss_asn1.h | ||
| gss_err.h | ||
| gss_krb5.h | ||
| gss_spkm3.h | ||
| metrics.h | ||
| msg_prot.h | ||
| rpc_pipe_fs.h | ||
| sched.h | ||
| stats.h | ||
| svc.h | ||
| svcauth.h | ||
| svcauth_gss.h | ||
| svcsock.h | ||
| timer.h | ||
| types.h | ||
| xdr.h | ||
| xprt.h | ||