mirror of https://github.com/xqemu/xqemu.git
block/iscsi: clarify the meaning of ISCSI_CHECKALLOC_THRES
Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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@ -95,7 +95,15 @@ typedef struct IscsiAIOCB {
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#define NOP_INTERVAL 5000
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#define NOP_INTERVAL 5000
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#define MAX_NOP_FAILURES 3
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#define MAX_NOP_FAILURES 3
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#define ISCSI_CMD_RETRIES 5
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#define ISCSI_CMD_RETRIES 5
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#define ISCSI_CHECKALLOC_THRES 63
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/* this threshhold is a trade-off knob to choose between
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* the potential additional overhead of an extra GET_LBA_STATUS request
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* vs. unnecessarily reading a lot of zero sectors over the wire.
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* If a read request is greater or equal than ISCSI_CHECKALLOC_THRES
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* sectors we check the allocation status of the area covered by the
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* request first if the allocationmap indicates that the area might be
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* unallocated. */
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#define ISCSI_CHECKALLOC_THRES 64
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static void
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static void
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iscsi_bh_cb(void *p)
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iscsi_bh_cb(void *p)
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@ -505,7 +513,7 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
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}
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}
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#if defined(LIBISCSI_FEATURE_IOVECTOR)
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#if defined(LIBISCSI_FEATURE_IOVECTOR)
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if (iscsilun->lbprz && nb_sectors > ISCSI_CHECKALLOC_THRES &&
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if (iscsilun->lbprz && nb_sectors >= ISCSI_CHECKALLOC_THRES &&
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!iscsi_allocationmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
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!iscsi_allocationmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
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int64_t ret;
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int64_t ret;
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int pnum;
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int pnum;
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