diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/file-posix.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/block/file-posix.c b/block/file-posix.c index 2da3a76355..0c1b81ce4b 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -527,9 +527,22 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->fd = -1; fd = qemu_open(filename, s->open_flags, 0644); - if (fd < 0) { - ret = -errno; - error_setg_errno(errp, errno, "Could not open '%s'", filename); + ret = fd < 0 ? -errno : 0; + + if (ret == -EACCES || ret == -EROFS) { + /* Try to degrade to read-only, but if it doesn't work, still use the + * normal error message. */ + if (bdrv_apply_auto_read_only(bs, NULL, NULL) == 0) { + bdrv_flags &= ~BDRV_O_RDWR; + raw_parse_flags(bdrv_flags, &s->open_flags); + assert(!(s->open_flags & O_CREAT)); + fd = qemu_open(filename, s->open_flags); + ret = fd < 0 ? -errno : 0; + } + } + + if (ret < 0) { + error_setg_errno(errp, -ret, "Could not open '%s'", filename); if (ret == -EROFS) { ret = -EACCES; } |