Message ID | 20210518083901.97369-3-pbonzini@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | block: file-posix queue | expand |
diff --git a/block/file-posix.c b/block/file-posix.c index e5ef006aee..77a45083a6 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1179,6 +1179,17 @@ static int sg_get_max_segments(int fd, struct stat *st) int sysfd = -1; long max_segments; + if (S_ISCHR(st->st_mode)) { + if (ioctl(fd, SG_GET_SG_TABLESIZE, &ret) == 0) { + return ret; + } + return -EIO; + } + + if (!S_ISBLK(st->st_mode)) { + return -ENOTSUP; + } + sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/max_segments", major(st->st_rdev), minor(st->st_rdev)); sysfd = open(sysfspath, O_RDONLY);
Even though it was only called for devices that have bs->sg set (which must be character devices), sg_get_max_segments looked at /sys/dev/block which only works for block devices. On Linux the sg driver has its own way to provide the maximum number of iovecs in a scatter/gather list. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- block/file-posix.c | 11 +++++++++++ 1 file changed, 11 insertions(+)