diff options
author | Eric Blake <eblake@redhat.com> | 2016-05-11 16:39:40 -0600 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-16 18:39:05 +0200 |
commit | f57e2416aaeb39c32946d282768ece7ff619b423 (patch) | |
tree | 8639bbec9008f7383d80207c9b286976898b4a72 /nbd/client.c | |
parent | 98494e3b926ad62c5644fd84a37f04b5e7abb7a6 (diff) | |
download | qemu-f57e2416aaeb39c32946d282768ece7ff619b423.zip qemu-f57e2416aaeb39c32946d282768ece7ff619b423.tar.gz qemu-f57e2416aaeb39c32946d282768ece7ff619b423.tar.bz2 |
nbd: Clean up ioctl handling of qemu-nbd -c
The kernel ioctl() interface into NBD is limited to 'unsigned long';
we MUST pass in input with that type (and not int or size_t, as
there may be platform ABIs where the wrong types promote incorrectly
through var-args). Furthermore, on 32-bit platforms, the kernel
is limited to a maximum export size of 2T (our BLKSIZE of 512 times
a SIZE_BLOCKS constrained by 32 bit unsigned long).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1463006384-7734-8-git-send-email-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'nbd/client.c')
-rw-r--r-- | nbd/client.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/nbd/client.c b/nbd/client.c index 5604aa9..20e6daf 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -593,9 +593,15 @@ fail: #ifdef __linux__ int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size) { + unsigned long sectors = size / BDRV_SECTOR_SIZE; + if (size / BDRV_SECTOR_SIZE != sectors) { + LOG("Export size %lld too large for 32-bit kernel", (long long) size); + return -E2BIG; + } + TRACE("Setting NBD socket"); - if (ioctl(fd, NBD_SET_SOCK, sioc->fd) < 0) { + if (ioctl(fd, NBD_SET_SOCK, (unsigned long) sioc->fd) < 0) { int serrno = errno; LOG("Failed to set NBD socket"); return -serrno; @@ -603,21 +609,25 @@ int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size) TRACE("Setting block size to %lu", (unsigned long)BDRV_SECTOR_SIZE); - if (ioctl(fd, NBD_SET_BLKSIZE, (size_t)BDRV_SECTOR_SIZE) < 0) { + if (ioctl(fd, NBD_SET_BLKSIZE, (unsigned long)BDRV_SECTOR_SIZE) < 0) { int serrno = errno; LOG("Failed setting NBD block size"); return -serrno; } - TRACE("Setting size to %zd block(s)", (size_t)(size / BDRV_SECTOR_SIZE)); + TRACE("Setting size to %lu block(s)", sectors); + if (size % BDRV_SECTOR_SIZE) { + TRACE("Ignoring trailing %d bytes of export", + (int) (size % BDRV_SECTOR_SIZE)); + } - if (ioctl(fd, NBD_SET_SIZE_BLOCKS, (size_t)(size / BDRV_SECTOR_SIZE)) < 0) { + if (ioctl(fd, NBD_SET_SIZE_BLOCKS, sectors) < 0) { int serrno = errno; LOG("Failed setting size (in blocks)"); return -serrno; } - if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) { + if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) flags) < 0) { if (errno == ENOTTY) { int read_only = (flags & NBD_FLAG_READ_ONLY) != 0; TRACE("Setting readonly attribute"); |