This commit (1c9805a398cc1125b4defa6367172c8c2c0bca9f in Git) breaks qemu-nbd for me. I cannot mount any VM image (raw or qcow2 format) with this commit or today's HEAD. Previous commit c5fbe57111ef59c315a71cd80e8b0af59e36ff21 works fine.
The qemu-nbd process hangs while reading disk: 31175 ? Ss 0:00 qemu-nbd --connect=/dev/nbd0 /tmp/lenny-vm.raw 31176 ? S 0:00 \_ qemu-nbd --connect=/dev/nbd0 /tmp/lenny-vm.raw 31177 ? D 0:00 \_ qemu-nbd --connect=/dev/nbd0 /tmp/lenny-vm.raw In dmesg I see only: [18304.541058] nbd0: Then, if I pkill -9 nbd, dmesg gets more verbose: [18467.288183] nbd (pid 31175: qemu-nbd) got signal 9 [18467.303175] nbd0: shutting down socket [18467.314446] nbd0: Receive control failed (result -4) [18467.329354] end_request: I/O error, dev nbd0, sector 0 [18467.344771] __ratelimit: 38 callbacks suppressed [18467.358620] Buffer I/O error on device nbd0, logical block 0 [18467.375591] Buffer I/O error on device nbd0, logical block 1 [18467.392560] Buffer I/O error on device nbd0, logical block 2 [18467.409530] Buffer I/O error on device nbd0, logical block 3 [18467.426508] nbd0: queue cleared [18467.435962] nbd0: Attempted send on closed socket [18467.450095] end_request: I/O error, dev nbd0, sector 0 [18467.465527] Buffer I/O error on device nbd0, logical block 0 [18467.482496] Buffer I/O error on device nbd0, logical block 1 [18467.499464] Buffer I/O error on device nbd0, logical block 2 [18467.516433] Buffer I/O error on device nbd0, logical block 3 [18467.533418] nbd0: Attempted send on closed socket [18467.547539] end_request: I/O error, dev nbd0, sector 0 [18467.562945] Buffer I/O error on device nbd0, logical block 0 [18467.579917] Buffer I/O error on device nbd0, logical block 1 [18467.596897] nbd0: Attempted send on closed socket [18467.611022] end_request: I/O error, dev nbd0, sector 0 [18467.626442] nbd0: Attempted send on closed socket [18467.640569] end_request: I/O error, dev nbd0, sector 0 [18467.655984] ldm_validate_partition_table(): Disk read failed. [18467.673242] nbd0: Attempted send on closed socket [18467.687369] end_request: I/O error, dev nbd0, sector 0 [18467.702788] nbd0: Attempted send on closed socket [18467.716915] end_request: I/O error, dev nbd0, sector 0 [18467.732359] nbd0: Attempted send on closed socket [18467.746487] end_request: I/O error, dev nbd0, sector 0 [18467.761931] nbd0: Attempted send on closed socket [18467.776058] end_request: I/O error, dev nbd0, sector 0 [18467.791473] Dev nbd0: unable to read RDB block 0 [18467.805348] nbd0: Attempted send on closed socket [18467.819479] end_request: I/O error, dev nbd0, sector 0 [18467.834897] nbd0: Attempted send on closed socket [18467.849025] end_request: I/O error, dev nbd0, sector 0 [18467.864446] nbd0: Attempted send on closed socket [18467.878572] end_request: I/O error, dev nbd0, sector 0 [18467.893985] unable to read partition table -- Pierre Riteau -- PhD student, Myriads team, IRISA, Rennes, France http://perso.univ-rennes1.fr/pierre.riteau/ On 14 oct. 2011, at 18:49, Kevin Wolf wrote: > From: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com> > > The bdrv_read()/bdrv_write() functions call .bdrv_read()/.bdrv_write(). > They should go through bdrv_co_do_readv() and bdrv_co_do_writev() > instead in order to unify request processing code across sync, aio, and > coroutine interfaces. This is also an important step towards removing > BlockDriverState .bdrv_read()/.bdrv_write() in the future. > > Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com> > Signed-off-by: Kevin Wolf <kw...@redhat.com> > --- > block.c | 112 +++++++++++++++++++++++++++++++++++---------------------------- > 1 files changed, 62 insertions(+), 50 deletions(-) > > diff --git a/block.c b/block.c > index f4731ec..ae8fc80 100644 > --- a/block.c > +++ b/block.c > @@ -44,6 +44,8 @@ > #include <windows.h> > #endif > > +#define NOT_DONE 0x7fffffff /* used while emulated sync operation in > progress */ > + > static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); > static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, > int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, > @@ -74,6 +76,8 @@ static int coroutine_fn bdrv_co_writev_em(BlockDriverState > *bs, > static int coroutine_fn bdrv_co_flush_em(BlockDriverState *bs); > static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, > int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); > +static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, > + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); > > static QTAILQ_HEAD(, BlockDriverState) bdrv_states = > QTAILQ_HEAD_INITIALIZER(bdrv_states); > @@ -1042,30 +1046,69 @@ static inline bool bdrv_has_async_flush(BlockDriver > *drv) > return drv->bdrv_aio_flush != bdrv_aio_flush_em; > } > > -/* return < 0 if error. See bdrv_write() for the return codes */ > -int bdrv_read(BlockDriverState *bs, int64_t sector_num, > - uint8_t *buf, int nb_sectors) > +typedef struct RwCo { > + BlockDriverState *bs; > + int64_t sector_num; > + int nb_sectors; > + QEMUIOVector *qiov; > + bool is_write; > + int ret; > +} RwCo; > + > +static void coroutine_fn bdrv_rw_co_entry(void *opaque) > { > - BlockDriver *drv = bs->drv; > + RwCo *rwco = opaque; > > - if (!drv) > - return -ENOMEDIUM; > + if (!rwco->is_write) { > + rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num, > + rwco->nb_sectors, rwco->qiov); > + } else { > + rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num, > + rwco->nb_sectors, rwco->qiov); > + } > +} > > - if (bdrv_has_async_rw(drv) && qemu_in_coroutine()) { > - QEMUIOVector qiov; > - struct iovec iov = { > - .iov_base = (void *)buf, > - .iov_len = nb_sectors * BDRV_SECTOR_SIZE, > - }; > +/* > + * Process a synchronous request using coroutines > + */ > +static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, > + int nb_sectors, bool is_write) > +{ > + QEMUIOVector qiov; > + struct iovec iov = { > + .iov_base = (void *)buf, > + .iov_len = nb_sectors * BDRV_SECTOR_SIZE, > + }; > + Coroutine *co; > + RwCo rwco = { > + .bs = bs, > + .sector_num = sector_num, > + .nb_sectors = nb_sectors, > + .qiov = &qiov, > + .is_write = is_write, > + .ret = NOT_DONE, > + }; > > - qemu_iovec_init_external(&qiov, &iov, 1); > - return bdrv_co_readv(bs, sector_num, nb_sectors, &qiov); > - } > + qemu_iovec_init_external(&qiov, &iov, 1); > > - if (bdrv_check_request(bs, sector_num, nb_sectors)) > - return -EIO; > + if (qemu_in_coroutine()) { > + /* Fast-path if already in coroutine context */ > + bdrv_rw_co_entry(&rwco); > + } else { > + co = qemu_coroutine_create(bdrv_rw_co_entry); > + qemu_coroutine_enter(co, &rwco); > + while (rwco.ret == NOT_DONE) { > + qemu_aio_wait(); > + } > + } > + return rwco.ret; > +} > > - return drv->bdrv_read(bs, sector_num, buf, nb_sectors); > +/* return < 0 if error. See bdrv_write() for the return codes */ > +int bdrv_read(BlockDriverState *bs, int64_t sector_num, > + uint8_t *buf, int nb_sectors) > +{ > + return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false); > } > > static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num, > @@ -1105,36 +1148,7 @@ static void set_dirty_bitmap(BlockDriverState *bs, > int64_t sector_num, > int bdrv_write(BlockDriverState *bs, int64_t sector_num, > const uint8_t *buf, int nb_sectors) > { > - BlockDriver *drv = bs->drv; > - > - if (!bs->drv) > - return -ENOMEDIUM; > - > - if (bdrv_has_async_rw(drv) && qemu_in_coroutine()) { > - QEMUIOVector qiov; > - struct iovec iov = { > - .iov_base = (void *)buf, > - .iov_len = nb_sectors * BDRV_SECTOR_SIZE, > - }; > - > - qemu_iovec_init_external(&qiov, &iov, 1); > - return bdrv_co_writev(bs, sector_num, nb_sectors, &qiov); > - } > - > - if (bs->read_only) > - return -EACCES; > - if (bdrv_check_request(bs, sector_num, nb_sectors)) > - return -EIO; > - > - if (bs->dirty_bitmap) { > - set_dirty_bitmap(bs, sector_num, nb_sectors, 1); > - } > - > - if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { > - bs->wr_highest_sector = sector_num + nb_sectors - 1; > - } > - > - return drv->bdrv_write(bs, sector_num, buf, nb_sectors); > + return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true); > } > > int bdrv_pread(BlockDriverState *bs, int64_t offset, > @@ -2912,8 +2926,6 @@ static void bdrv_rw_em_cb(void *opaque, int ret) > *(int *)opaque = ret; > } > > -#define NOT_DONE 0x7fffffff > - > static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num, > uint8_t *buf, int nb_sectors) > { > -- > 1.7.6.4 > >
