From ee40c217e373b538e227f7218b09c1c794b4124a Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Sun, 16 Jun 2013 19:48:52 -0700 Subject: [PATCH] client: fix sync read zeroing at EOF If we have a read that hits EOF, we need to do a short read. Previously we would zero the buffer if we were completely withing the file, but we also need to zero things if we overlap with EOF. This fixes a hang of mpi-fsx on ceph-fuse. Triggered/tested by LibCephFS.MulticlientHoleEOF. Fixes: #5368 Signed-off-by: Sage Weil Reviewed-by: Greg Farnum --- src/client/Client.cc | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/src/client/Client.cc b/src/client/Client.cc index 204dc98d74d05..dec364567b62f 100644 --- a/src/client/Client.cc +++ b/src/client/Client.cc @@ -5826,13 +5826,17 @@ int Client::_read_sync(Fh *f, uint64_t off, uint64_t len, bufferlist *bl) } // short read? if (r >= 0 && r < wanted) { - if (pos + left <= in->size) { - // hole, zero and return. - bufferptr z(left); + if (pos < in->size) { + // zero up to known EOF + int some = MIN(in->size - pos, left); + bufferptr z(some); z.zero(); bl->push_back(z); - read += left; - return read; + read += some; + pos += some; + left -= some; + if (left == 0) + return read; } // reverify size -- 2.39.5