* [Qemu-devel] [PULL 1/2] block/iscsi: use a bh to schedule co reentrance
2013-12-20 22:45 [Qemu-devel] [PULL 0/2] SCSI changes for 2013-12-20 Paolo Bonzini
@ 2013-12-20 22:45 ` Paolo Bonzini
2013-12-20 22:45 ` [Qemu-devel] [PULL 2/2] scsi-disk: add non-zero MAX UNMAP LBA COUNT to block limits VPD page Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2013-12-20 22:45 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Lieven, qemu-stable
From: Peter Lieven <pl@kamp.de>
this fixes a potential segfault and performance regression.
If the coroutine is reentered directly in the iscsi_co_generic_cb
iscsi_process_{read,write} are interrupted and reentered any
time later. One the one hand this could happen after an iscsi_close
where the iscsi context is already gone (segfault). On the
other hand this limits the number of processed callbacks
in each aio_dispatch to one (potential performance regression).
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
block/iscsi.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index fa69408..b0e6eea 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -68,6 +68,7 @@ typedef struct IscsiTask {
int do_retry;
struct scsi_task *task;
Coroutine *co;
+ QEMUBH *bh;
} IscsiTask;
typedef struct IscsiAIOCB {
@@ -123,6 +124,13 @@ iscsi_schedule_bh(IscsiAIOCB *acb)
qemu_bh_schedule(acb->bh);
}
+static void iscsi_co_generic_bh_cb(void *opaque)
+{
+ struct IscsiTask *iTask = opaque;
+ qemu_bh_delete(iTask->bh);
+ qemu_coroutine_enter(iTask->co, NULL);
+}
+
static void
iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
@@ -147,7 +155,8 @@ iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
out:
if (iTask->co) {
- qemu_coroutine_enter(iTask->co, NULL);
+ iTask->bh = qemu_bh_new(iscsi_co_generic_bh_cb, iTask);
+ qemu_bh_schedule(iTask->bh);
}
}
--
1.8.4.2
^ permalink raw reply related [flat|nested] 3+ messages in thread* [Qemu-devel] [PULL 2/2] scsi-disk: add non-zero MAX UNMAP LBA COUNT to block limits VPD page
2013-12-20 22:45 [Qemu-devel] [PULL 0/2] SCSI changes for 2013-12-20 Paolo Bonzini
2013-12-20 22:45 ` [Qemu-devel] [PULL 1/2] block/iscsi: use a bh to schedule co reentrance Paolo Bonzini
@ 2013-12-20 22:45 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2013-12-20 22:45 UTC (permalink / raw)
To: qemu-devel
Linux prefers WRITE SAME to UNMAP if the count is zero, and WRITE
SAME does not discard anything unless the device can guarantee that
the resulting block is zero.
This fixes thin provisioning on glusterfs.
Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
hw/scsi/scsi-disk.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 7653411..e42b3f2 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -47,6 +47,7 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
#define SCSI_MAX_MODE_LEN 256
#define DEFAULT_DISCARD_GRANULARITY 4096
+#define DEFAULT_MAX_UNMAP_SIZE (1 << 30) /* 1 GB */
typedef struct SCSIDiskState SCSIDiskState;
@@ -74,6 +75,7 @@ struct SCSIDiskState
bool media_event;
bool eject_request;
uint64_t wwn;
+ uint64_t max_unmap_size;
QEMUBH *bh;
char *version;
char *serial;
@@ -625,6 +627,8 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
s->qdev.conf.min_io_size / s->qdev.blocksize;
unsigned int opt_io_size =
s->qdev.conf.opt_io_size / s->qdev.blocksize;
+ unsigned int max_unmap_sectors =
+ s->max_unmap_size / s->qdev.blocksize;
if (s->qdev.type == TYPE_ROM) {
DPRINTF("Inquiry (EVPD[%02X] not supported for CDROM\n",
@@ -647,6 +651,12 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
outbuf[14] = (opt_io_size >> 8) & 0xff;
outbuf[15] = opt_io_size & 0xff;
+ /* maximum unmap LBA count, hardcoded to 1GB */
+ outbuf[20] = (max_unmap_sectors >> 24) & 0xff;
+ outbuf[21] = (max_unmap_sectors >> 16) & 0xff;
+ outbuf[22] = (max_unmap_sectors >> 8) & 0xff;
+ outbuf[23] = max_unmap_sectors & 0xff;
+
/* optimal unmap granularity */
outbuf[28] = (unmap_sectors >> 24) & 0xff;
outbuf[29] = (unmap_sectors >> 16) & 0xff;
@@ -2519,6 +2529,8 @@ static Property scsi_hd_properties[] = {
DEFINE_PROP_BIT("dpofua", SCSIDiskState, features,
SCSI_DISK_F_DPOFUA, false),
DEFINE_PROP_HEX64("wwn", SCSIDiskState, wwn, 0),
+ DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
+ DEFAULT_MAX_UNMAP_SIZE),
DEFINE_BLOCK_CHS_PROPERTIES(SCSIDiskState, qdev.conf),
DEFINE_PROP_END_OF_LIST(),
};
@@ -2628,6 +2640,8 @@ static Property scsi_disk_properties[] = {
DEFINE_PROP_BIT("dpofua", SCSIDiskState, features,
SCSI_DISK_F_DPOFUA, false),
DEFINE_PROP_HEX64("wwn", SCSIDiskState, wwn, 0),
+ DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
+ DEFAULT_MAX_UNMAP_SIZE),
DEFINE_PROP_END_OF_LIST(),
};
--
1.8.4.2
^ permalink raw reply related [flat|nested] 3+ messages in thread