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iscsi: do not use aio_context_acquire/release

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Now that all bottom halves and callbacks take care of taking the
AioContext lock, we can migrate some users away from it and to a
specific QemuMutex or CoMutex.

Protect libiscsi calls with a QemuMutex.  Callbacks are invoked
using bottom halves, so we don't even have to drop it around
callback invocations.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170222180725.28611-4-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-02-22 19:07:25 +01:00 committed by Stefan Hajnoczi
parent 37d1e4d9bf
commit d045c466d9
1 changed files with 64 additions and 19 deletions
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83
block/iscsi.c
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@ -58,6 +58,7 @@ typedef struct IscsiLun {
int events; int events;
QEMUTimer *nop_timer; QEMUTimer *nop_timer;
QEMUTimer *event_timer; QEMUTimer *event_timer;
QemuMutex mutex;
struct scsi_inquiry_logical_block_provisioning lbp; struct scsi_inquiry_logical_block_provisioning lbp;
struct scsi_inquiry_block_limits bl; struct scsi_inquiry_block_limits bl;
unsigned char *zeroblock; unsigned char *zeroblock;
@ -252,6 +253,7 @@ static int iscsi_translate_sense(struct scsi_sense *sense)
return ret; return ret;
} }
/* Called (via iscsi_service) with QemuMutex held. */
static void static void
iscsi_co_generic_cb(struct iscsi_context *iscsi, int status, iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque) void *command_data, void *opaque)
@ -352,6 +354,7 @@ static const AIOCBInfo iscsi_aiocb_info = {
static void iscsi_process_read(void *arg); static void iscsi_process_read(void *arg);
static void iscsi_process_write(void *arg); static void iscsi_process_write(void *arg);
/* Called with QemuMutex held. */
static void static void
iscsi_set_events(IscsiLun *iscsilun) iscsi_set_events(IscsiLun *iscsilun)
{ {
@ -395,10 +398,10 @@ iscsi_process_read(void *arg)
IscsiLun *iscsilun = arg; IscsiLun *iscsilun = arg;
struct iscsi_context *iscsi = iscsilun->iscsi; struct iscsi_context *iscsi = iscsilun->iscsi;
aio_context_acquire(iscsilun->aio_context); qemu_mutex_lock(&iscsilun->mutex);
iscsi_service(iscsi, POLLIN); iscsi_service(iscsi, POLLIN);
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
aio_context_release(iscsilun->aio_context); qemu_mutex_unlock(&iscsilun->mutex);
} }
static void static void
@ -407,10 +410,10 @@ iscsi_process_write(void *arg)
IscsiLun *iscsilun = arg; IscsiLun *iscsilun = arg;
struct iscsi_context *iscsi = iscsilun->iscsi; struct iscsi_context *iscsi = iscsilun->iscsi;
aio_context_acquire(iscsilun->aio_context); qemu_mutex_lock(&iscsilun->mutex);
iscsi_service(iscsi, POLLOUT); iscsi_service(iscsi, POLLOUT);
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
aio_context_release(iscsilun->aio_context); qemu_mutex_unlock(&iscsilun->mutex);
} }
static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun) static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
@ -589,6 +592,7 @@ iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
uint64_t lba; uint64_t lba;
uint32_t num_sectors; uint32_t num_sectors;
bool fua = flags & BDRV_REQ_FUA; bool fua = flags & BDRV_REQ_FUA;
int r = 0;
if (fua) { if (fua) {
assert(iscsilun->dpofua); assert(iscsilun->dpofua);
@ -604,6 +608,7 @@ iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
lba = sector_qemu2lun(sector_num, iscsilun); lba = sector_qemu2lun(sector_num, iscsilun);
num_sectors = sector_qemu2lun(nb_sectors, iscsilun); num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
iscsi_co_init_iscsitask(iscsilun, &iTask); iscsi_co_init_iscsitask(iscsilun, &iTask);
qemu_mutex_lock(&iscsilun->mutex);
retry: retry:
if (iscsilun->use_16_for_rw) { if (iscsilun->use_16_for_rw) {
#if LIBISCSI_API_VERSION >= (20160603) #if LIBISCSI_API_VERSION >= (20160603)
@ -640,7 +645,9 @@ retry:
#endif #endif
while (!iTask.complete) { while (!iTask.complete) {
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
qemu_coroutine_yield(); qemu_coroutine_yield();
qemu_mutex_lock(&iscsilun->mutex);
} }
if (iTask.task != NULL) { if (iTask.task != NULL) {
@ -655,12 +662,15 @@ retry:
if (iTask.status != SCSI_STATUS_GOOD) { if (iTask.status != SCSI_STATUS_GOOD) {
iscsi_allocmap_set_invalid(iscsilun, sector_num, nb_sectors); iscsi_allocmap_set_invalid(iscsilun, sector_num, nb_sectors);
return iTask.err_code; r = iTask.err_code;
goto out_unlock;
} }
iscsi_allocmap_set_allocated(iscsilun, sector_num, nb_sectors); iscsi_allocmap_set_allocated(iscsilun, sector_num, nb_sectors);
return 0; out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
return r;
} }
@ -693,18 +703,21 @@ static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
goto out; goto out;
} }
qemu_mutex_lock(&iscsilun->mutex);
retry: retry:
if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun, if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
sector_qemu2lun(sector_num, iscsilun), sector_qemu2lun(sector_num, iscsilun),
8 + 16, iscsi_co_generic_cb, 8 + 16, iscsi_co_generic_cb,
&iTask) == NULL) { &iTask) == NULL) {
ret = -ENOMEM; ret = -ENOMEM;
goto out; goto out_unlock;
} }
while (!iTask.complete) { while (!iTask.complete) {
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
qemu_coroutine_yield(); qemu_coroutine_yield();
qemu_mutex_lock(&iscsilun->mutex);
} }
if (iTask.do_retry) { if (iTask.do_retry) {
@ -721,20 +734,20 @@ retry:
* because the device is busy or the cmd is not * because the device is busy or the cmd is not
* supported) we pretend all blocks are allocated * supported) we pretend all blocks are allocated
* for backwards compatibility */ * for backwards compatibility */
goto out; goto out_unlock;
} }
lbas = scsi_datain_unmarshall(iTask.task); lbas = scsi_datain_unmarshall(iTask.task);
if (lbas == NULL) { if (lbas == NULL) {
ret = -EIO; ret = -EIO;
goto out; goto out_unlock;
} }
lbasd = &lbas->descriptors[0]; lbasd = &lbas->descriptors[0];
if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) { if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
ret = -EIO; ret = -EIO;
goto out; goto out_unlock;
} }
*pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun); *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
@ -756,6 +769,8 @@ retry:
if (*pnum > nb_sectors) { if (*pnum > nb_sectors) {
*pnum = nb_sectors; *pnum = nb_sectors;
} }
out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
out: out:
if (iTask.task != NULL) { if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task); scsi_free_scsi_task(iTask.task);
@ -818,6 +833,7 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
num_sectors = sector_qemu2lun(nb_sectors, iscsilun); num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
iscsi_co_init_iscsitask(iscsilun, &iTask); iscsi_co_init_iscsitask(iscsilun, &iTask);
qemu_mutex_lock(&iscsilun->mutex);
retry: retry:
if (iscsilun->use_16_for_rw) { if (iscsilun->use_16_for_rw) {
#if LIBISCSI_API_VERSION >= (20160603) #if LIBISCSI_API_VERSION >= (20160603)
@ -855,7 +871,9 @@ retry:
#endif #endif
while (!iTask.complete) { while (!iTask.complete) {
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
qemu_coroutine_yield(); qemu_coroutine_yield();
qemu_mutex_lock(&iscsilun->mutex);
} }
if (iTask.task != NULL) { if (iTask.task != NULL) {
@ -867,6 +885,7 @@ retry:
iTask.complete = 0; iTask.complete = 0;
goto retry; goto retry;
} }
qemu_mutex_unlock(&iscsilun->mutex);
if (iTask.status != SCSI_STATUS_GOOD) { if (iTask.status != SCSI_STATUS_GOOD) {
return iTask.err_code; return iTask.err_code;
@ -881,6 +900,7 @@ static int coroutine_fn iscsi_co_flush(BlockDriverState *bs)
struct IscsiTask iTask; struct IscsiTask iTask;
iscsi_co_init_iscsitask(iscsilun, &iTask); iscsi_co_init_iscsitask(iscsilun, &iTask);
qemu_mutex_lock(&iscsilun->mutex);
retry: retry:
if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0, if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
0, iscsi_co_generic_cb, &iTask) == NULL) { 0, iscsi_co_generic_cb, &iTask) == NULL) {
@ -889,7 +909,9 @@ retry:
while (!iTask.complete) { while (!iTask.complete) {
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
qemu_coroutine_yield(); qemu_coroutine_yield();
qemu_mutex_lock(&iscsilun->mutex);
} }
if (iTask.task != NULL) { if (iTask.task != NULL) {
@ -901,6 +923,7 @@ retry:
iTask.complete = 0; iTask.complete = 0;
goto retry; goto retry;
} }
qemu_mutex_unlock(&iscsilun->mutex);
if (iTask.status != SCSI_STATUS_GOOD) { if (iTask.status != SCSI_STATUS_GOOD) {
return iTask.err_code; return iTask.err_code;
@ -910,6 +933,7 @@ retry:
} }
#ifdef __linux__ #ifdef __linux__
/* Called (via iscsi_service) with QemuMutex held. */
static void static void
iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status, iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque) void *command_data, void *opaque)
@ -1034,6 +1058,7 @@ static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
acb->task->expxferlen = acb->ioh->dxfer_len; acb->task->expxferlen = acb->ioh->dxfer_len;
data.size = 0; data.size = 0;
qemu_mutex_lock(&iscsilun->mutex);
if (acb->task->xfer_dir == SCSI_XFER_WRITE) { if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
if (acb->ioh->iovec_count == 0) { if (acb->ioh->iovec_count == 0) {
data.data = acb->ioh->dxferp; data.data = acb->ioh->dxferp;
@ -1049,6 +1074,7 @@ static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
iscsi_aio_ioctl_cb, iscsi_aio_ioctl_cb,
(data.size > 0) ? &data : NULL, (data.size > 0) ? &data : NULL,
acb) != 0) { acb) != 0) {
qemu_mutex_unlock(&iscsilun->mutex);
scsi_free_scsi_task(acb->task); scsi_free_scsi_task(acb->task);
qemu_aio_unref(acb); qemu_aio_unref(acb);
return NULL; return NULL;
@ -1068,6 +1094,7 @@ static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
} }
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
return &acb->common; return &acb->common;
} }
@ -1092,6 +1119,7 @@ coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
IscsiLun *iscsilun = bs->opaque; IscsiLun *iscsilun = bs->opaque;
struct IscsiTask iTask; struct IscsiTask iTask;
struct unmap_list list; struct unmap_list list;
int r = 0;
if (!is_byte_request_lun_aligned(offset, count, iscsilun)) { if (!is_byte_request_lun_aligned(offset, count, iscsilun)) {
return -ENOTSUP; return -ENOTSUP;
@ -1106,15 +1134,19 @@ coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
list.num = count / iscsilun->block_size; list.num = count / iscsilun->block_size;
iscsi_co_init_iscsitask(iscsilun, &iTask); iscsi_co_init_iscsitask(iscsilun, &iTask);
qemu_mutex_lock(&iscsilun->mutex);
retry: retry:
if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1, if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
iscsi_co_generic_cb, &iTask) == NULL) { iscsi_co_generic_cb, &iTask) == NULL) {
return -ENOMEM; r = -ENOMEM;
goto out_unlock;
} }
while (!iTask.complete) { while (!iTask.complete) {
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
qemu_coroutine_yield(); qemu_coroutine_yield();
qemu_mutex_lock(&iscsilun->mutex);
} }
if (iTask.task != NULL) { if (iTask.task != NULL) {
@ -1131,17 +1163,20 @@ retry:
/* the target might fail with a check condition if it /* the target might fail with a check condition if it
is not happy with the alignment of the UNMAP request is not happy with the alignment of the UNMAP request
we silently fail in this case */ we silently fail in this case */
return 0; goto out_unlock;
} }
if (iTask.status != SCSI_STATUS_GOOD) { if (iTask.status != SCSI_STATUS_GOOD) {
return iTask.err_code; r = iTask.err_code;
goto out_unlock;
} }
iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS, iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
count >> BDRV_SECTOR_BITS); count >> BDRV_SECTOR_BITS);
return 0; out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
return r;
} }
static int static int
@ -1153,6 +1188,7 @@ coroutine_fn iscsi_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
uint64_t lba; uint64_t lba;
uint32_t nb_blocks; uint32_t nb_blocks;
bool use_16_for_ws = iscsilun->use_16_for_rw; bool use_16_for_ws = iscsilun->use_16_for_rw;
int r = 0;
if (!is_byte_request_lun_aligned(offset, count, iscsilun)) { if (!is_byte_request_lun_aligned(offset, count, iscsilun)) {
return -ENOTSUP; return -ENOTSUP;
@ -1186,6 +1222,7 @@ coroutine_fn iscsi_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
} }
} }
qemu_mutex_lock(&iscsilun->mutex);
iscsi_co_init_iscsitask(iscsilun, &iTask); iscsi_co_init_iscsitask(iscsilun, &iTask);
retry: retry:
if (use_16_for_ws) { if (use_16_for_ws) {
@ -1205,7 +1242,9 @@ retry:
while (!iTask.complete) { while (!iTask.complete) {
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
qemu_mutex_unlock(&iscsilun->mutex);
qemu_coroutine_yield(); qemu_coroutine_yield();
qemu_mutex_lock(&iscsilun->mutex);
} }
if (iTask.status == SCSI_STATUS_CHECK_CONDITION && if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
@ -1215,7 +1254,8 @@ retry:
/* WRITE SAME is not supported by the target */ /* WRITE SAME is not supported by the target */
iscsilun->has_write_same = false; iscsilun->has_write_same = false;
scsi_free_scsi_task(iTask.task); scsi_free_scsi_task(iTask.task);
return -ENOTSUP; r = -ENOTSUP;
goto out_unlock;
} }
if (iTask.task != NULL) { if (iTask.task != NULL) {
@ -1231,7 +1271,8 @@ retry:
if (iTask.status != SCSI_STATUS_GOOD) { if (iTask.status != SCSI_STATUS_GOOD) {
iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS, iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
count >> BDRV_SECTOR_BITS); count >> BDRV_SECTOR_BITS);
return iTask.err_code; r = iTask.err_code;
goto out_unlock;
} }
if (flags & BDRV_REQ_MAY_UNMAP) { if (flags & BDRV_REQ_MAY_UNMAP) {
@ -1242,7 +1283,9 @@ retry:
count >> BDRV_SECTOR_BITS); count >> BDRV_SECTOR_BITS);
} }
return 0; out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
return r;
} }
static void apply_chap(struct iscsi_context *iscsi, QemuOpts *opts, static void apply_chap(struct iscsi_context *iscsi, QemuOpts *opts,
@ -1331,7 +1374,7 @@ static void iscsi_nop_timed_event(void *opaque)
{ {
IscsiLun *iscsilun = opaque; IscsiLun *iscsilun = opaque;
aio_context_acquire(iscsilun->aio_context); qemu_mutex_lock(&iscsilun->mutex);
if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) { if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) {
error_report("iSCSI: NOP timeout. Reconnecting..."); error_report("iSCSI: NOP timeout. Reconnecting...");
iscsilun->request_timed_out = true; iscsilun->request_timed_out = true;
@ -1344,7 +1387,7 @@ static void iscsi_nop_timed_event(void *opaque)
iscsi_set_events(iscsilun); iscsi_set_events(iscsilun);
out: out:
aio_context_release(iscsilun->aio_context); qemu_mutex_unlock(&iscsilun->mutex);
} }
static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp) static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp)
@ -1890,6 +1933,7 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
scsi_free_scsi_task(task); scsi_free_scsi_task(task);
task = NULL; task = NULL;
qemu_mutex_init(&iscsilun->mutex);
iscsi_attach_aio_context(bs, iscsilun->aio_context); iscsi_attach_aio_context(bs, iscsilun->aio_context);
/* Guess the internal cluster (page) size of the iscsi target by the means /* Guess the internal cluster (page) size of the iscsi target by the means
@ -1935,6 +1979,7 @@ static void iscsi_close(BlockDriverState *bs)
iscsi_destroy_context(iscsi); iscsi_destroy_context(iscsi);
g_free(iscsilun->zeroblock); g_free(iscsilun->zeroblock);
iscsi_allocmap_free(iscsilun); iscsi_allocmap_free(iscsilun);
qemu_mutex_destroy(&iscsilun->mutex);
memset(iscsilun, 0, sizeof(IscsiLun)); memset(iscsilun, 0, sizeof(IscsiLun));
} }