diff options
| author | Eric Blake <eblake@redhat.com> | 2016-07-21 13:34:46 -0600 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-08-03 18:44:56 +0200 |
| commit | 7423f417827146f956df820f172d0bf80a489495 (patch) | |
| tree | c344d494cc4fab46a7bb1daacb0088bc35e9ee1f /include | |
| parent | 5bee0f4717c4c67394aaade0c5a9cee3d42cc614 (diff) | |
nbd: Limit nbdflags to 16 bits
Rather than asserting that nbdflags is within range, just give
it the correct type to begin with :) nbdflags corresponds to
the per-export portion of NBD Protocol "transmission flags", which
is 16 bits in response to NBD_OPT_EXPORT_NAME and NBD_OPT_GO.
Furthermore, upstream NBD has never passed the global flags to
the kernel via ioctl(NBD_SET_FLAGS) (the ioctl was first
introduced in NBD 2.9.22; then a latent bug in NBD 3.1 actually
tried to OR the global flags with the transmission flags, with
the disaster that the addition of NBD_FLAG_NO_ZEROES in 3.9
caused all earlier NBD 3.x clients to treat every export as
read-only; NBD 3.10 and later intentionally clip things to 16
bits to pass only transmission flags). Qemu should follow suit,
since the current two global flags (NBD_FLAG_FIXED_NEWSTYLE
and NBD_FLAG_NO_ZEROES) have no impact on the kernel's behavior
during transmission.
CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1469129688-22848-3-git-send-email-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/nbd.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/block/nbd.h b/include/block/nbd.h index cb91820f38..1897557a9b 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -90,11 +90,11 @@ ssize_t nbd_wr_syncv(QIOChannel *ioc, size_t niov, size_t length, bool do_read); -int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags, +int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, QCryptoTLSCreds *tlscreds, const char *hostname, QIOChannel **outioc, off_t *size, Error **errp); -int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size); +int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size); ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request); ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply); int nbd_client(int fd); @@ -104,7 +104,7 @@ typedef struct NBDExport NBDExport; typedef struct NBDClient NBDClient; NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size, - uint32_t nbdflags, void (*close)(NBDExport *), + uint16_t nbdflags, void (*close)(NBDExport *), Error **errp); void nbd_export_close(NBDExport *exp); void nbd_export_get(NBDExport *exp); |