From: Wen Congyang <we...@cn.fujitsu.com>
Currently, starting a datacopier requires a valid read and write fd, but this
is a problem when purely sending data from a local buffer to a writable fd.
The prefixdata mechanism already exists and works for inserting data from a
local buffer ahead of reading from the read fd.
Make the lack of a read fd non-fatal. A datacopier with no read fd, but some
prefixdata will write the prefixdata to the write fd and complete successfully.
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
[Rewrite commit message]
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
CC: Ian Campbell <ian.campb...@citrix.com>
CC: Ian Jackson <ian.jack...@eu.citrix.com>
CC: Wei Liu <wei.l...@citrix.com>
---
v2: Rewrite commit message. No code change
---
tools/libxl/libxl_aoutils.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/tools/libxl/libxl_aoutils.c b/tools/libxl/libxl_aoutils.c
index b10d2e1..3e0c0ae 100644
--- a/tools/libxl/libxl_aoutils.c
+++ b/tools/libxl/libxl_aoutils.c
@@ -309,9 +309,11 @@ int libxl__datacopier_start(libxl__datacopier_state *dc)
libxl__datacopier_init(dc);
- rc = libxl__ev_fd_register(gc, &dc->toread, datacopier_readable,
- dc->readfd, POLLIN);
- if (rc) goto out;
+ if (dc->readfd >= 0) {
+ rc = libxl__ev_fd_register(gc, &dc->toread, datacopier_readable,
+ dc->readfd, POLLIN);
+ if (rc) goto out;
+ }
rc = libxl__ev_fd_register(gc, &dc->towrite, datacopier_writable,
dc->writefd, POLLOUT);
--
1.7.10.4
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