Message ID | 1389968119-24771-16-git-send-email-kwolf@redhat.com |
---|---|
State | New |
Headers | show |
Le Friday 17 Jan 2014 à 15:15:05 (+0100), Kevin Wolf a écrit : > Previously, it was not possible to use wait_for_overlapping_requests() > between tracked_request_begin()/end() because it would wait for itself. > > Ignore the current request in the overlap check and run more of the > bdrv_co_do_preadv/pwritev code with a BdrvTrackedRequest present. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > Reviewed-by: Max Reitz <mreitz@redhat.com> > --- > block.c | 38 ++++++++++++++++++++------------------ > 1 file changed, 20 insertions(+), 18 deletions(-) > > diff --git a/block.c b/block.c > index 85f28ab..18dcd43 100644 > --- a/block.c > +++ b/block.c > @@ -2106,7 +2106,7 @@ static bool tracked_request_overlaps(BdrvTrackedRequest *req, > } > > static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, > - int64_t offset, unsigned int bytes) > + BdrvTrackedRequest *self, int64_t offset, unsigned int bytes) > { > BdrvTrackedRequest *req; > int64_t cluster_offset; > @@ -2124,6 +2124,9 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, > do { > retry = false; > QLIST_FOREACH(req, &bs->tracked_requests, list) { > + if (req == self) { > + continue; > + } > if (tracked_request_overlaps(req, cluster_offset, cluster_bytes)) { > /* Hitting this means there was a reentrant request, for > * example, a block driver issuing nested requests. This must > @@ -2726,10 +2729,10 @@ err: > * implemented by the caller. > */ > static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, > - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) > + BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, > + QEMUIOVector *qiov, int flags) > { > BlockDriver *drv = bs->drv; > - BdrvTrackedRequest req; > int ret; > > int64_t sector_num = offset >> BDRV_SECTOR_BITS; > @@ -2744,11 +2747,9 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, > } > > if (bs->copy_on_read_in_flight) { > - wait_for_overlapping_requests(bs, offset, bytes); > + wait_for_overlapping_requests(bs, req, offset, bytes); > } > > - tracked_request_begin(&req, bs, offset, bytes, false); > - > if (flags & BDRV_REQ_COPY_ON_READ) { > int pnum; > > @@ -2795,8 +2796,6 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, > } > > out: > - tracked_request_end(&req); > - > if (flags & BDRV_REQ_COPY_ON_READ) { > bs->copy_on_read_in_flight--; > } > @@ -2812,6 +2811,8 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, > BdrvRequestFlags flags) > { > BlockDriver *drv = bs->drv; > + BdrvTrackedRequest req; > + > /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ > uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); > uint8_t *head_buf = NULL; > @@ -2862,9 +2863,11 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, > bytes = ROUND_UP(bytes, align); > } > > - ret = bdrv_aligned_preadv(bs, offset, bytes, > + tracked_request_begin(&req, bs, offset, bytes, false); > + ret = bdrv_aligned_preadv(bs, &req, offset, bytes, > use_local_qiov ? &local_qiov : qiov, > flags); > + tracked_request_end(&req); > > if (use_local_qiov) { > qemu_iovec_destroy(&local_qiov); > @@ -2983,10 +2986,10 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, > * Forwards an already correctly aligned write request to the BlockDriver. > */ > static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, > - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) > + BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, > + QEMUIOVector *qiov, int flags) > { > BlockDriver *drv = bs->drv; > - BdrvTrackedRequest req; > int ret; > > int64_t sector_num = offset >> BDRV_SECTOR_BITS; > @@ -2996,12 +2999,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, > assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); > > if (bs->copy_on_read_in_flight) { > - wait_for_overlapping_requests(bs, offset, bytes); > + wait_for_overlapping_requests(bs, req, offset, bytes); > } > > - tracked_request_begin(&req, bs, offset, bytes, true); > - > - ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); > + ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); > > if (ret < 0) { > /* Do nothing, write notifier decided to fail this request */ > @@ -3024,8 +3025,6 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, > bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); > } > > - tracked_request_end(&req); > - > return ret; > } > > @@ -3036,6 +3035,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, > int64_t offset, unsigned int bytes, QEMUIOVector *qiov, > BdrvRequestFlags flags) > { > + BdrvTrackedRequest req; > int ret; > > if (!bs->drv) { > @@ -3054,7 +3054,9 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, > bdrv_io_limits_intercept(bs, bytes >> BDRV_SECTOR_BITS, true); > } > > - ret = bdrv_aligned_pwritev(bs, offset, bytes, qiov, flags); > + tracked_request_begin(&req, bs, offset, bytes, true); > + ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, qiov, flags); > + tracked_request_end(&req); > > return ret; > } > -- > 1.8.1.4 > > Reviewed-by: Benoit Canet <benoit@irqsave.net>
diff --git a/block.c b/block.c index 85f28ab..18dcd43 100644 --- a/block.c +++ b/block.c @@ -2106,7 +2106,7 @@ static bool tracked_request_overlaps(BdrvTrackedRequest *req, } static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, - int64_t offset, unsigned int bytes) + BdrvTrackedRequest *self, int64_t offset, unsigned int bytes) { BdrvTrackedRequest *req; int64_t cluster_offset; @@ -2124,6 +2124,9 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, do { retry = false; QLIST_FOREACH(req, &bs->tracked_requests, list) { + if (req == self) { + continue; + } if (tracked_request_overlaps(req, cluster_offset, cluster_bytes)) { /* Hitting this means there was a reentrant request, for * example, a block driver issuing nested requests. This must @@ -2726,10 +2729,10 @@ err: * implemented by the caller. */ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) + BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, + QEMUIOVector *qiov, int flags) { BlockDriver *drv = bs->drv; - BdrvTrackedRequest req; int ret; int64_t sector_num = offset >> BDRV_SECTOR_BITS; @@ -2744,11 +2747,9 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, } if (bs->copy_on_read_in_flight) { - wait_for_overlapping_requests(bs, offset, bytes); + wait_for_overlapping_requests(bs, req, offset, bytes); } - tracked_request_begin(&req, bs, offset, bytes, false); - if (flags & BDRV_REQ_COPY_ON_READ) { int pnum; @@ -2795,8 +2796,6 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, } out: - tracked_request_end(&req); - if (flags & BDRV_REQ_COPY_ON_READ) { bs->copy_on_read_in_flight--; } @@ -2812,6 +2811,8 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, BdrvRequestFlags flags) { BlockDriver *drv = bs->drv; + BdrvTrackedRequest req; + /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); uint8_t *head_buf = NULL; @@ -2862,9 +2863,11 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, bytes = ROUND_UP(bytes, align); } - ret = bdrv_aligned_preadv(bs, offset, bytes, + tracked_request_begin(&req, bs, offset, bytes, false); + ret = bdrv_aligned_preadv(bs, &req, offset, bytes, use_local_qiov ? &local_qiov : qiov, flags); + tracked_request_end(&req); if (use_local_qiov) { qemu_iovec_destroy(&local_qiov); @@ -2983,10 +2986,10 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, * Forwards an already correctly aligned write request to the BlockDriver. */ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) + BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, + QEMUIOVector *qiov, int flags) { BlockDriver *drv = bs->drv; - BdrvTrackedRequest req; int ret; int64_t sector_num = offset >> BDRV_SECTOR_BITS; @@ -2996,12 +2999,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); if (bs->copy_on_read_in_flight) { - wait_for_overlapping_requests(bs, offset, bytes); + wait_for_overlapping_requests(bs, req, offset, bytes); } - tracked_request_begin(&req, bs, offset, bytes, true); - - ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); + ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); if (ret < 0) { /* Do nothing, write notifier decided to fail this request */ @@ -3024,8 +3025,6 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); } - tracked_request_end(&req); - return ret; } @@ -3036,6 +3035,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) { + BdrvTrackedRequest req; int ret; if (!bs->drv) { @@ -3054,7 +3054,9 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, bdrv_io_limits_intercept(bs, bytes >> BDRV_SECTOR_BITS, true); } - ret = bdrv_aligned_pwritev(bs, offset, bytes, qiov, flags); + tracked_request_begin(&req, bs, offset, bytes, true); + ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, qiov, flags); + tracked_request_end(&req); return ret; }