On 10/12/18 6:55 AM, Kevin Wolf wrote:
If read-only=off, but auto-read-only=on is given, open the file
read-write if we have the permissions, but instead of erroring out for
read-only files, just degrade to read-only.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/gluster.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/block/gluster.c b/block/gluster.c
index 4fd55a9cc5..68d20c8830 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -849,6 +849,15 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict
*options,
qemu_gluster_parse_flags(bdrv_flags, &open_flags);
s->fd = glfs_open(s->glfs, gconf->path, open_flags);
+ if (!s->fd && errno == EACCES) {
EROFS is not possible as it was for posix file?
+ /* Try to degrade to read-only, but if it doesn't work, still use the
+ * normal error message. */
+ ret = bdrv_apply_auto_read_only(bs, NULL, NULL);
No guarantees on what errno is on failure...
+ if (ret == 0) {
+ open_flags = (open_flags & ~O_RDWR) | O_RDONLY;
+ s->fd = glfs_open(s->glfs, gconf->path, open_flags);
+ }
+ }
if (!s->fd) {
ret = -errno;
...but you are relying on it here. (Same story as in the posix driver)
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org