Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-12 23:23:03 +00:00
Code Issues Packages Projects Releases Wiki Activity

um: chan_user: retry partial writes

Browse Source 
In the next commit, we are going to set the output FD to be blocking.
Once that is done, the write() may be short if an interrupt happens
while it is writing out data. As such, to properly catch an EINTR error,
we need to retry the write.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Benjamin Berg 2023-10-18 14:36:42 +02:00 committed by Johannes Berg
parent c6c4cbaa01
commit 4cfb44df8d
1 changed files with 15 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/um/drivers/chan_user.c
View File

@ -37,11 +37,23 @@ int generic_read(int fd, __u8 *c_out, void *unused)
int generic_write(int fd, const __u8 *buf, size_t n, void *unused)
{
int written = 0;
int err;
CATCH_EINTR(err = write(fd, buf, n));
if (err > 0)
return err;
/* The FD may be in blocking mode, as such, need to retry short writes,
* they may have been interrupted by a signal.
*/
do {
errno = 0;
err = write(fd, buf + written, n - written);
if (err > 0) {
written += err;
continue;
}
} while (err < 0 && errno == EINTR);
if (written > 0)
return written;
else if (errno == EAGAIN)
return 0;
else if (err == 0)