From bdad13b9deec47d5d9eaf7f43867d19a79471244 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 4 Sep 2013 19:00:22 +0200 Subject: [PATCH] block: make bdrv_co_is_allocated static bdrv_is_allocated can detect coroutine context and go through a fast path, similar to other block layer functions. Reviewed-by: Eric Blake Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi --- block.c | 24 +++++++++++++++--------- block/backup.c | 4 ++-- block/raw_bsd.c | 2 +- block/stream.c | 4 ++-- include/block/block.h | 2 -- 5 files changed, 20 insertions(+), 16 deletions(-) diff --git a/block.c b/block.c index d9a3a7f9db..f27bab6809 100644 --- a/block.c +++ b/block.c @@ -2587,7 +2587,7 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, if (flags & BDRV_REQ_COPY_ON_READ) { int pnum; - ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum); + ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum); if (ret < 0) { goto out; } @@ -3061,8 +3061,9 @@ typedef struct BdrvCoIsAllocatedData { * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes * beyond the end of the disk image it will be clamped. */ -int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num, - int nb_sectors, int *pnum) +static int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, + int64_t sector_num, + int nb_sectors, int *pnum) { int64_t n; @@ -3112,10 +3113,15 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, .done = false, }; - co = qemu_coroutine_create(bdrv_is_allocated_co_entry); - qemu_coroutine_enter(co, &data); - while (!data.done) { - qemu_aio_wait(); + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + bdrv_is_allocated_co_entry(&data); + } else { + co = qemu_coroutine_create(bdrv_is_allocated_co_entry); + qemu_coroutine_enter(co, &data); + while (!data.done) { + qemu_aio_wait(); + } } return data.ret; } @@ -3143,8 +3149,8 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, intermediate = top; while (intermediate && intermediate != base) { int pnum_inter; - ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors, - &pnum_inter); + ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors, + &pnum_inter); if (ret < 0) { return ret; } else if (ret) { diff --git a/block/backup.c b/block/backup.c index 47fb23fb61..04c4b5c263 100644 --- a/block/backup.c +++ b/block/backup.c @@ -289,14 +289,14 @@ static void coroutine_fn backup_run(void *opaque) * backing file. */ for (i = 0; i < BACKUP_SECTORS_PER_CLUSTER;) { - /* bdrv_co_is_allocated() only returns true/false based + /* bdrv_is_allocated() only returns true/false based * on the first set of sectors it comes across that * are are all in the same state. * For that reason we must verify each sector in the * backup cluster length. We end up copying more than * needed but at some point that is always the case. */ alloced = - bdrv_co_is_allocated(bs, + bdrv_is_allocated(bs, start * BACKUP_SECTORS_PER_CLUSTER + i, BACKUP_SECTORS_PER_CLUSTER - i, &n); i += n; diff --git a/block/raw_bsd.c b/block/raw_bsd.c index ab2b0fd7d2..926712ed27 100644 --- a/block/raw_bsd.c +++ b/block/raw_bsd.c @@ -62,7 +62,7 @@ static int coroutine_fn raw_co_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { - return bdrv_co_is_allocated(bs->file, sector_num, nb_sectors, pnum); + return bdrv_is_allocated(bs->file, sector_num, nb_sectors, pnum); } static int coroutine_fn raw_co_write_zeroes(BlockDriverState *bs, diff --git a/block/stream.c b/block/stream.c index 7aa250061c..fe242baae0 100644 --- a/block/stream.c +++ b/block/stream.c @@ -119,8 +119,8 @@ wait: break; } - ret = bdrv_co_is_allocated(bs, sector_num, - STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n); + ret = bdrv_is_allocated(bs, sector_num, + STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n); if (ret == 1) { /* Allocated in the top, no need to copy. */ copy = false; diff --git a/include/block/block.h b/include/block/block.h index 107f5a04e9..de75d2dbfd 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -179,8 +179,6 @@ int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, */ int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num, int nb_sectors); -int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num, - int nb_sectors, int *pnum); int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, BlockDriverState *base, int64_t sector_num, -- GitLab