* [Qemu-devel] [PATCH v3 2/2] block: move I/O request processing to block/io.c
2015-04-27 15:53 [Qemu-devel] [PATCH v3 0/2] block: move I/O request processing to block/io.c Stefan Hajnoczi
2015-04-27 15:53 ` [Qemu-devel] [PATCH v3 1/2] block: replace bdrv_states iteration with bdrv_next() Stefan Hajnoczi
@ 2015-04-27 15:53 ` Stefan Hajnoczi
2015-04-27 16:28 ` Eric Blake
2015-04-27 16:26 ` [Qemu-devel] [PATCH v3 0/2] " Eric Blake
2 siblings, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2015-04-27 15:53 UTC (permalink / raw)
To: qemu-devel; +Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block
The block.c file has grown to over 6000 lines. It is time to split this
file so there are fewer conflicts and the code is easier to maintain.
Extract I/O request processing code:
* Read
* Write
* Zero writes and making the image empty
* Flush
* Discard
* ioctl
* Tracked requests and queuing
* Throttling and copy-on-read
* Block status and allocated functions
* Refreshing block limits
* Reading/writing vmstate
* qemu_blockalign() and friends
The patch simply moves code from block.c into block/io.c.
No code changes are made except adding the following block_int.h
functions so they can be called across block.c and block/io.c:
bdrv_set_dirty(), bdrv_reset_dirty().
I/O request processing needs to set up BlockDriver coroutine and AIO
emulation function pointers, so add bdrv_setup_io_funcs(bdrv) interface
that block.c calls.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block.c | 2521 +--------------------------------------------
block/Makefile.objs | 2 +-
include/block/block_int.h | 12 +
3 files changed, 18 insertions(+), 2517 deletions(-)
diff --git a/block.c b/block.c
index 1f0a4e2..7904098 100644
--- a/block.c
+++ b/block.c
@@ -30,7 +30,6 @@
#include "qapi/qmp/qjson.h"
#include "sysemu/block-backend.h"
#include "sysemu/sysemu.h"
-#include "sysemu/qtest.h"
#include "qemu/notify.h"
#include "block/coroutine.h"
#include "block/qapi.h"
@@ -71,36 +70,6 @@ struct BdrvDirtyBitmap {
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
-static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque);
-static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque);
-static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov);
-static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov);
-static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BdrvRequestFlags flags,
- BlockCompletionFunc *cb,
- void *opaque,
- bool is_write);
-static void coroutine_fn bdrv_co_do_rw(void *opaque);
-static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
-
static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
QTAILQ_HEAD_INITIALIZER(bdrv_states);
@@ -110,10 +79,6 @@ static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
static QLIST_HEAD(, BlockDriver) bdrv_drivers =
QLIST_HEAD_INITIALIZER(bdrv_drivers);
-static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
- int nr_sectors);
-static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
- int nr_sectors);
static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
/* If non-zero, use only whitelisted block drivers */
static int use_bdrv_whitelist;
@@ -138,110 +103,6 @@ int is_windows_drive(const char *filename)
}
#endif
-/* throttling disk I/O limits */
-void bdrv_set_io_limits(BlockDriverState *bs,
- ThrottleConfig *cfg)
-{
- int i;
-
- throttle_config(&bs->throttle_state, cfg);
-
- for (i = 0; i < 2; i++) {
- qemu_co_enter_next(&bs->throttled_reqs[i]);
- }
-}
-
-/* this function drain all the throttled IOs */
-static bool bdrv_start_throttled_reqs(BlockDriverState *bs)
-{
- bool drained = false;
- bool enabled = bs->io_limits_enabled;
- int i;
-
- bs->io_limits_enabled = false;
-
- for (i = 0; i < 2; i++) {
- while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
- drained = true;
- }
- }
-
- bs->io_limits_enabled = enabled;
-
- return drained;
-}
-
-void bdrv_io_limits_disable(BlockDriverState *bs)
-{
- bs->io_limits_enabled = false;
-
- bdrv_start_throttled_reqs(bs);
-
- throttle_destroy(&bs->throttle_state);
-}
-
-static void bdrv_throttle_read_timer_cb(void *opaque)
-{
- BlockDriverState *bs = opaque;
- qemu_co_enter_next(&bs->throttled_reqs[0]);
-}
-
-static void bdrv_throttle_write_timer_cb(void *opaque)
-{
- BlockDriverState *bs = opaque;
- qemu_co_enter_next(&bs->throttled_reqs[1]);
-}
-
-/* should be called before bdrv_set_io_limits if a limit is set */
-void bdrv_io_limits_enable(BlockDriverState *bs)
-{
- int clock_type = QEMU_CLOCK_REALTIME;
-
- if (qtest_enabled()) {
- /* For testing block IO throttling only */
- clock_type = QEMU_CLOCK_VIRTUAL;
- }
- assert(!bs->io_limits_enabled);
- throttle_init(&bs->throttle_state,
- bdrv_get_aio_context(bs),
- clock_type,
- bdrv_throttle_read_timer_cb,
- bdrv_throttle_write_timer_cb,
- bs);
- bs->io_limits_enabled = true;
-}
-
-/* This function makes an IO wait if needed
- *
- * @nb_sectors: the number of sectors of the IO
- * @is_write: is the IO a write
- */
-static void bdrv_io_limits_intercept(BlockDriverState *bs,
- unsigned int bytes,
- bool is_write)
-{
- /* does this io must wait */
- bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write);
-
- /* if must wait or any request of this type throttled queue the IO */
- if (must_wait ||
- !qemu_co_queue_empty(&bs->throttled_reqs[is_write])) {
- qemu_co_queue_wait(&bs->throttled_reqs[is_write]);
- }
-
- /* the IO will be executed, do the accounting */
- throttle_account(&bs->throttle_state, is_write, bytes);
-
-
- /* if the next request must wait -> do nothing */
- if (throttle_schedule_timer(&bs->throttle_state, is_write)) {
- return;
- }
-
- /* else queue next request for execution */
- qemu_co_queue_next(&bs->throttled_reqs[is_write]);
-}
-
size_t bdrv_opt_mem_align(BlockDriverState *bs)
{
if (!bs || !bs->drv) {
@@ -355,20 +216,7 @@ void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
void bdrv_register(BlockDriver *bdrv)
{
- /* Block drivers without coroutine functions need emulation */
- if (!bdrv->bdrv_co_readv) {
- bdrv->bdrv_co_readv = bdrv_co_readv_em;
- bdrv->bdrv_co_writev = bdrv_co_writev_em;
-
- /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
- * the block driver lacks aio we need to emulate that too.
- */
- if (!bdrv->bdrv_aio_readv) {
- /* add AIO emulation layer */
- bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
- bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
- }
- }
+ bdrv_setup_io_funcs(bdrv);
QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
}
@@ -540,54 +388,6 @@ int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
return ret;
}
-void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
-{
- BlockDriver *drv = bs->drv;
- Error *local_err = NULL;
-
- memset(&bs->bl, 0, sizeof(bs->bl));
-
- if (!drv) {
- return;
- }
-
- /* Take some limits from the children as a default */
- if (bs->file) {
- bdrv_refresh_limits(bs->file, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
- bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length;
- bs->bl.max_transfer_length = bs->file->bl.max_transfer_length;
- bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
- } else {
- bs->bl.opt_mem_alignment = 512;
- }
-
- if (bs->backing_hd) {
- bdrv_refresh_limits(bs->backing_hd, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
- bs->bl.opt_transfer_length =
- MAX(bs->bl.opt_transfer_length,
- bs->backing_hd->bl.opt_transfer_length);
- bs->bl.max_transfer_length =
- MIN_NON_ZERO(bs->bl.max_transfer_length,
- bs->backing_hd->bl.max_transfer_length);
- bs->bl.opt_mem_alignment =
- MAX(bs->bl.opt_mem_alignment,
- bs->backing_hd->bl.opt_mem_alignment);
- }
-
- /* Then let the driver override it */
- if (drv->bdrv_refresh_limits) {
- drv->bdrv_refresh_limits(bs, errp);
- }
-}
-
/**
* Try to get @bs's logical and physical block size.
* On success, store them in @bsz struct and return 0.
@@ -861,22 +661,6 @@ int bdrv_parse_cache_flags(const char *mode, int *flags)
return 0;
}
-/**
- * The copy-on-read flag is actually a reference count so multiple users may
- * use the feature without worrying about clobbering its previous state.
- * Copy-on-read stays enabled until all users have called to disable it.
- */
-void bdrv_enable_copy_on_read(BlockDriverState *bs)
-{
- bs->copy_on_read++;
-}
-
-void bdrv_disable_copy_on_read(BlockDriverState *bs)
-{
- assert(bs->copy_on_read > 0);
- bs->copy_on_read--;
-}
-
/*
* Returns the flags that a temporary snapshot should get, based on the
* originally requested flags (the originally requested image will have flags
@@ -1986,108 +1770,6 @@ void bdrv_close_all(void)
}
}
-/* Check if any requests are in-flight (including throttled requests) */
-static bool bdrv_requests_pending(BlockDriverState *bs)
-{
- if (!QLIST_EMPTY(&bs->tracked_requests)) {
- return true;
- }
- if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) {
- return true;
- }
- if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) {
- return true;
- }
- if (bs->file && bdrv_requests_pending(bs->file)) {
- return true;
- }
- if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
- return true;
- }
- return false;
-}
-
-static bool bdrv_drain_one(BlockDriverState *bs)
-{
- bool bs_busy;
-
- bdrv_flush_io_queue(bs);
- bdrv_start_throttled_reqs(bs);
- bs_busy = bdrv_requests_pending(bs);
- bs_busy |= aio_poll(bdrv_get_aio_context(bs), bs_busy);
- return bs_busy;
-}
-
-/*
- * Wait for pending requests to complete on a single BlockDriverState subtree
- *
- * See the warning in bdrv_drain_all(). This function can only be called if
- * you are sure nothing can generate I/O because you have op blockers
- * installed.
- *
- * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState
- * AioContext.
- */
-void bdrv_drain(BlockDriverState *bs)
-{
- while (bdrv_drain_one(bs)) {
- /* Keep iterating */
- }
-}
-
-/*
- * Wait for pending requests to complete across all BlockDriverStates
- *
- * This function does not flush data to disk, use bdrv_flush_all() for that
- * after calling this function.
- *
- * Note that completion of an asynchronous I/O operation can trigger any
- * number of other I/O operations on other devices---for example a coroutine
- * can be arbitrarily complex and a constant flow of I/O can come until the
- * coroutine is complete. Because of this, it is not possible to have a
- * function to drain a single device's I/O queue.
- */
-void bdrv_drain_all(void)
-{
- /* Always run first iteration so any pending completion BHs run */
- bool busy = true;
- BlockDriverState *bs = NULL;
-
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- aio_context_acquire(aio_context);
- if (bs->job) {
- block_job_pause(bs->job);
- }
- aio_context_release(aio_context);
- }
-
- while (busy) {
- busy = false;
- bs = NULL;
-
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- aio_context_acquire(aio_context);
- busy |= bdrv_drain_one(bs);
- aio_context_release(aio_context);
- }
- }
-
- bs = NULL;
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- aio_context_acquire(aio_context);
- if (bs->job) {
- block_job_resume(bs->job);
- }
- aio_context_release(aio_context);
- }
-}
-
/* make a BlockDriverState anonymous by removing from bdrv_state and
* graph_bdrv_state list.
Also, NULL terminate the device_name to prevent double remove */
@@ -2409,152 +2091,6 @@ int bdrv_commit_all(void)
return 0;
}
-/**
- * Remove an active request from the tracked requests list
- *
- * This function should be called when a tracked request is completing.
- */
-static void tracked_request_end(BdrvTrackedRequest *req)
-{
- if (req->serialising) {
- req->bs->serialising_in_flight--;
- }
-
- QLIST_REMOVE(req, list);
- qemu_co_queue_restart_all(&req->wait_queue);
-}
-
-/**
- * Add an active request to the tracked requests list
- */
-static void tracked_request_begin(BdrvTrackedRequest *req,
- BlockDriverState *bs,
- int64_t offset,
- unsigned int bytes, bool is_write)
-{
- *req = (BdrvTrackedRequest){
- .bs = bs,
- .offset = offset,
- .bytes = bytes,
- .is_write = is_write,
- .co = qemu_coroutine_self(),
- .serialising = false,
- .overlap_offset = offset,
- .overlap_bytes = bytes,
- };
-
- qemu_co_queue_init(&req->wait_queue);
-
- QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
-}
-
-static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
-{
- int64_t overlap_offset = req->offset & ~(align - 1);
- unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
- - overlap_offset;
-
- if (!req->serialising) {
- req->bs->serialising_in_flight++;
- req->serialising = true;
- }
-
- req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
- req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
-}
-
-/**
- * Round a region to cluster boundaries
- */
-void bdrv_round_to_clusters(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- int64_t *cluster_sector_num,
- int *cluster_nb_sectors)
-{
- BlockDriverInfo bdi;
-
- if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
- *cluster_sector_num = sector_num;
- *cluster_nb_sectors = nb_sectors;
- } else {
- int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
- *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
- *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
- nb_sectors, c);
- }
-}
-
-static int bdrv_get_cluster_size(BlockDriverState *bs)
-{
- BlockDriverInfo bdi;
- int ret;
-
- ret = bdrv_get_info(bs, &bdi);
- if (ret < 0 || bdi.cluster_size == 0) {
- return bs->request_alignment;
- } else {
- return bdi.cluster_size;
- }
-}
-
-static bool tracked_request_overlaps(BdrvTrackedRequest *req,
- int64_t offset, unsigned int bytes)
-{
- /* aaaa bbbb */
- if (offset >= req->overlap_offset + req->overlap_bytes) {
- return false;
- }
- /* bbbb aaaa */
- if (req->overlap_offset >= offset + bytes) {
- return false;
- }
- return true;
-}
-
-static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
-{
- BlockDriverState *bs = self->bs;
- BdrvTrackedRequest *req;
- bool retry;
- bool waited = false;
-
- if (!bs->serialising_in_flight) {
- return false;
- }
-
- do {
- retry = false;
- QLIST_FOREACH(req, &bs->tracked_requests, list) {
- if (req == self || (!req->serialising && !self->serialising)) {
- continue;
- }
- if (tracked_request_overlaps(req, self->overlap_offset,
- self->overlap_bytes))
- {
- /* Hitting this means there was a reentrant request, for
- * example, a block driver issuing nested requests. This must
- * never happen since it means deadlock.
- */
- assert(qemu_coroutine_self() != req->co);
-
- /* If the request is already (indirectly) waiting for us, or
- * will wait for us as soon as it wakes up, then just go on
- * (instead of producing a deadlock in the former case). */
- if (!req->waiting_for) {
- self->waiting_for = req;
- qemu_co_queue_wait(&req->wait_queue);
- self->waiting_for = NULL;
- retry = true;
- waited = true;
- break;
- }
- }
- }
- } while (retry);
-
- return waited;
-}
-
/*
* Return values:
* 0 - success
@@ -2723,879 +2259,6 @@ exit:
return ret;
}
-
-static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
- size_t size)
-{
- if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
- return -EIO;
- }
-
- if (!bdrv_is_inserted(bs)) {
- return -ENOMEDIUM;
- }
-
- if (offset < 0) {
- return -EIO;
- }
-
- return 0;
-}
-
-static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors)
-{
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EIO;
- }
-
- return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
- nb_sectors * BDRV_SECTOR_SIZE);
-}
-
-typedef struct RwCo {
- BlockDriverState *bs;
- int64_t offset;
- QEMUIOVector *qiov;
- bool is_write;
- int ret;
- BdrvRequestFlags flags;
-} RwCo;
-
-static void coroutine_fn bdrv_rw_co_entry(void *opaque)
-{
- RwCo *rwco = opaque;
-
- if (!rwco->is_write) {
- rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset,
- rwco->qiov->size, rwco->qiov,
- rwco->flags);
- } else {
- rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset,
- rwco->qiov->size, rwco->qiov,
- rwco->flags);
- }
-}
-
-/*
- * Process a vectored synchronous request using coroutines
- */
-static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
- QEMUIOVector *qiov, bool is_write,
- BdrvRequestFlags flags)
-{
- Coroutine *co;
- RwCo rwco = {
- .bs = bs,
- .offset = offset,
- .qiov = qiov,
- .is_write = is_write,
- .ret = NOT_DONE,
- .flags = flags,
- };
-
- /**
- * In sync call context, when the vcpu is blocked, this throttling timer
- * will not fire; so the I/O throttling function has to be disabled here
- * if it has been enabled.
- */
- if (bs->io_limits_enabled) {
- fprintf(stderr, "Disabling I/O throttling on '%s' due "
- "to synchronous I/O.\n", bdrv_get_device_name(bs));
- bdrv_io_limits_disable(bs);
- }
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_rw_co_entry(&rwco);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_rw_co_entry);
- qemu_coroutine_enter(co, &rwco);
- while (rwco.ret == NOT_DONE) {
- aio_poll(aio_context, true);
- }
- }
- return rwco.ret;
-}
-
-/*
- * Process a synchronous request using coroutines
- */
-static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
- int nb_sectors, bool is_write, BdrvRequestFlags flags)
-{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *)buf,
- .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
- };
-
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EINVAL;
- }
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS,
- &qiov, is_write, flags);
-}
-
-/* return < 0 if error. See bdrv_write() for the return codes */
-int bdrv_read(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors)
-{
- return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0);
-}
-
-/* Just like bdrv_read(), but with I/O throttling temporarily disabled */
-int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors)
-{
- bool enabled;
- int ret;
-
- enabled = bs->io_limits_enabled;
- bs->io_limits_enabled = false;
- ret = bdrv_read(bs, sector_num, buf, nb_sectors);
- bs->io_limits_enabled = enabled;
- return ret;
-}
-
-/* Return < 0 if error. Important errors are:
- -EIO generic I/O error (may happen for all errors)
- -ENOMEDIUM No media inserted.
- -EINVAL Invalid sector number or nb_sectors
- -EACCES Trying to write a read-only device
-*/
-int bdrv_write(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
-{
- return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
-}
-
-int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, BdrvRequestFlags flags)
-{
- return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
- BDRV_REQ_ZERO_WRITE | flags);
-}
-
-/*
- * Completely zero out a block device with the help of bdrv_write_zeroes.
- * The operation is sped up by checking the block status and only writing
- * zeroes to the device if they currently do not return zeroes. Optional
- * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP).
- *
- * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
- */
-int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
-{
- int64_t target_sectors, ret, nb_sectors, sector_num = 0;
- int n;
-
- target_sectors = bdrv_nb_sectors(bs);
- if (target_sectors < 0) {
- return target_sectors;
- }
-
- for (;;) {
- nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS);
- if (nb_sectors <= 0) {
- return 0;
- }
- ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n);
- if (ret < 0) {
- error_report("error getting block status at sector %" PRId64 ": %s",
- sector_num, strerror(-ret));
- return ret;
- }
- if (ret & BDRV_BLOCK_ZERO) {
- sector_num += n;
- continue;
- }
- ret = bdrv_write_zeroes(bs, sector_num, n, flags);
- if (ret < 0) {
- error_report("error writing zeroes at sector %" PRId64 ": %s",
- sector_num, strerror(-ret));
- return ret;
- }
- sector_num += n;
- }
-}
-
-int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
-{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *)buf,
- .iov_len = bytes,
- };
- int ret;
-
- if (bytes < 0) {
- return -EINVAL;
- }
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
- if (ret < 0) {
- return ret;
- }
-
- return bytes;
-}
-
-int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
-{
- int ret;
-
- ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
- if (ret < 0) {
- return ret;
- }
-
- return qiov->size;
-}
-
-int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
- const void *buf, int bytes)
-{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *) buf,
- .iov_len = bytes,
- };
-
- if (bytes < 0) {
- return -EINVAL;
- }
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_pwritev(bs, offset, &qiov);
-}
-
-/*
- * Writes to the file and ensures that no writes are reordered across this
- * request (acts as a barrier)
- *
- * Returns 0 on success, -errno in error cases.
- */
-int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
- const void *buf, int count)
-{
- int ret;
-
- ret = bdrv_pwrite(bs, offset, buf, count);
- if (ret < 0) {
- return ret;
- }
-
- /* No flush needed for cache modes that already do it */
- if (bs->enable_write_cache) {
- bdrv_flush(bs);
- }
-
- return 0;
-}
-
-static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
-{
- /* Perform I/O through a temporary buffer so that users who scribble over
- * their read buffer while the operation is in progress do not end up
- * modifying the image file. This is critical for zero-copy guest I/O
- * where anything might happen inside guest memory.
- */
- void *bounce_buffer;
-
- BlockDriver *drv = bs->drv;
- struct iovec iov;
- QEMUIOVector bounce_qiov;
- int64_t cluster_sector_num;
- int cluster_nb_sectors;
- size_t skip_bytes;
- int ret;
-
- /* Cover entire cluster so no additional backing file I/O is required when
- * allocating cluster in the image file.
- */
- bdrv_round_to_clusters(bs, sector_num, nb_sectors,
- &cluster_sector_num, &cluster_nb_sectors);
-
- trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
- cluster_sector_num, cluster_nb_sectors);
-
- iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
- iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
- if (bounce_buffer == NULL) {
- ret = -ENOMEM;
- goto err;
- }
-
- qemu_iovec_init_external(&bounce_qiov, &iov, 1);
-
- ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors,
- &bounce_qiov);
- if (ret < 0) {
- goto err;
- }
-
- if (drv->bdrv_co_write_zeroes &&
- buffer_is_zero(bounce_buffer, iov.iov_len)) {
- ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
- cluster_nb_sectors, 0);
- } else {
- /* This does not change the data on the disk, it is not necessary
- * to flush even in cache=writethrough mode.
- */
- ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
- &bounce_qiov);
- }
-
- if (ret < 0) {
- /* It might be okay to ignore write errors for guest requests. If this
- * is a deliberate copy-on-read then we don't want to ignore the error.
- * Simply report it in all cases.
- */
- goto err;
- }
-
- skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
- qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
- nb_sectors * BDRV_SECTOR_SIZE);
-
-err:
- qemu_vfree(bounce_buffer);
- return ret;
-}
-
-/*
- * Forwards an already correctly aligned request to the BlockDriver. This
- * handles copy on read and zeroing after EOF; any other features must be
- * implemented by the caller.
- */
-static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
- BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- int64_t align, QEMUIOVector *qiov, int flags)
-{
- BlockDriver *drv = bs->drv;
- int ret;
-
- int64_t sector_num = offset >> BDRV_SECTOR_BITS;
- unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
-
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert(!qiov || bytes == qiov->size);
-
- /* Handle Copy on Read and associated serialisation */
- if (flags & BDRV_REQ_COPY_ON_READ) {
- /* If we touch the same cluster it counts as an overlap. This
- * guarantees that allocating writes will be serialized and not race
- * with each other for the same cluster. For example, in copy-on-read
- * it ensures that the CoR read and write operations are atomic and
- * guest writes cannot interleave between them. */
- mark_request_serialising(req, bdrv_get_cluster_size(bs));
- }
-
- wait_serialising_requests(req);
-
- if (flags & BDRV_REQ_COPY_ON_READ) {
- int pnum;
-
- ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum);
- if (ret < 0) {
- goto out;
- }
-
- if (!ret || pnum != nb_sectors) {
- ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
- goto out;
- }
- }
-
- /* Forward the request to the BlockDriver */
- if (!bs->zero_beyond_eof) {
- ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
- } else {
- /* Read zeros after EOF */
- int64_t total_sectors, max_nb_sectors;
-
- total_sectors = bdrv_nb_sectors(bs);
- if (total_sectors < 0) {
- ret = total_sectors;
- goto out;
- }
-
- max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
- align >> BDRV_SECTOR_BITS);
- if (nb_sectors < max_nb_sectors) {
- ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
- } else if (max_nb_sectors > 0) {
- QEMUIOVector local_qiov;
-
- qemu_iovec_init(&local_qiov, qiov->niov);
- qemu_iovec_concat(&local_qiov, qiov, 0,
- max_nb_sectors * BDRV_SECTOR_SIZE);
-
- ret = drv->bdrv_co_readv(bs, sector_num, max_nb_sectors,
- &local_qiov);
-
- qemu_iovec_destroy(&local_qiov);
- } else {
- ret = 0;
- }
-
- /* Reading beyond end of file is supposed to produce zeroes */
- if (ret == 0 && total_sectors < sector_num + nb_sectors) {
- uint64_t offset = MAX(0, total_sectors - sector_num);
- uint64_t bytes = (sector_num + nb_sectors - offset) *
- BDRV_SECTOR_SIZE;
- qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
- }
- }
-
-out:
- return ret;
-}
-
-static inline uint64_t bdrv_get_align(BlockDriverState *bs)
-{
- /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
- return MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
-}
-
-static inline bool bdrv_req_is_aligned(BlockDriverState *bs,
- int64_t offset, size_t bytes)
-{
- int64_t align = bdrv_get_align(bs);
- return !(offset & (align - 1) || (bytes & (align - 1)));
-}
-
-/*
- * Handle a read request in coroutine context
- */
-static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- BlockDriver *drv = bs->drv;
- BdrvTrackedRequest req;
-
- uint64_t align = bdrv_get_align(bs);
- uint8_t *head_buf = NULL;
- uint8_t *tail_buf = NULL;
- QEMUIOVector local_qiov;
- bool use_local_qiov = false;
- int ret;
-
- if (!drv) {
- return -ENOMEDIUM;
- }
-
- ret = bdrv_check_byte_request(bs, offset, bytes);
- if (ret < 0) {
- return ret;
- }
-
- if (bs->copy_on_read) {
- flags |= BDRV_REQ_COPY_ON_READ;
- }
-
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, bytes, false);
- }
-
- /* Align read if necessary by padding qiov */
- if (offset & (align - 1)) {
- head_buf = qemu_blockalign(bs, align);
- qemu_iovec_init(&local_qiov, qiov->niov + 2);
- qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
-
- bytes += offset & (align - 1);
- offset = offset & ~(align - 1);
- }
-
- if ((offset + bytes) & (align - 1)) {
- if (!use_local_qiov) {
- qemu_iovec_init(&local_qiov, qiov->niov + 1);
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
- }
- tail_buf = qemu_blockalign(bs, align);
- qemu_iovec_add(&local_qiov, tail_buf,
- align - ((offset + bytes) & (align - 1)));
-
- bytes = ROUND_UP(bytes, align);
- }
-
- tracked_request_begin(&req, bs, offset, bytes, false);
- ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
- use_local_qiov ? &local_qiov : qiov,
- flags);
- tracked_request_end(&req);
-
- if (use_local_qiov) {
- qemu_iovec_destroy(&local_qiov);
- qemu_vfree(head_buf);
- qemu_vfree(tail_buf);
- }
-
- return ret;
-}
-
-static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EINVAL;
- }
-
- return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
-}
-
-int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *qiov)
-{
- trace_bdrv_co_readv(bs, sector_num, nb_sectors);
-
- return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
-}
-
-int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
-{
- trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors);
-
- return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
- BDRV_REQ_COPY_ON_READ);
-}
-
-#define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
-
-static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
-{
- BlockDriver *drv = bs->drv;
- QEMUIOVector qiov;
- struct iovec iov = {0};
- int ret = 0;
-
- int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes,
- BDRV_REQUEST_MAX_SECTORS);
-
- while (nb_sectors > 0 && !ret) {
- int num = nb_sectors;
-
- /* Align request. Block drivers can expect the "bulk" of the request
- * to be aligned.
- */
- if (bs->bl.write_zeroes_alignment
- && num > bs->bl.write_zeroes_alignment) {
- if (sector_num % bs->bl.write_zeroes_alignment != 0) {
- /* Make a small request up to the first aligned sector. */
- num = bs->bl.write_zeroes_alignment;
- num -= sector_num % bs->bl.write_zeroes_alignment;
- } else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) {
- /* Shorten the request to the last aligned sector. num cannot
- * underflow because num > bs->bl.write_zeroes_alignment.
- */
- num -= (sector_num + num) % bs->bl.write_zeroes_alignment;
- }
- }
-
- /* limit request size */
- if (num > max_write_zeroes) {
- num = max_write_zeroes;
- }
-
- ret = -ENOTSUP;
- /* First try the efficient write zeroes operation */
- if (drv->bdrv_co_write_zeroes) {
- ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags);
- }
-
- if (ret == -ENOTSUP) {
- /* Fall back to bounce buffer if write zeroes is unsupported */
- int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length,
- MAX_WRITE_ZEROES_BOUNCE_BUFFER);
- num = MIN(num, max_xfer_len);
- iov.iov_len = num * BDRV_SECTOR_SIZE;
- if (iov.iov_base == NULL) {
- iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE);
- if (iov.iov_base == NULL) {
- ret = -ENOMEM;
- goto fail;
- }
- memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE);
- }
- qemu_iovec_init_external(&qiov, &iov, 1);
-
- ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov);
-
- /* Keep bounce buffer around if it is big enough for all
- * all future requests.
- */
- if (num < max_xfer_len) {
- qemu_vfree(iov.iov_base);
- iov.iov_base = NULL;
- }
- }
-
- sector_num += num;
- nb_sectors -= num;
- }
-
-fail:
- qemu_vfree(iov.iov_base);
- return ret;
-}
-
-/*
- * Forwards an already correctly aligned write request to the BlockDriver.
- */
-static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
- BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- QEMUIOVector *qiov, int flags)
-{
- BlockDriver *drv = bs->drv;
- bool waited;
- int ret;
-
- int64_t sector_num = offset >> BDRV_SECTOR_BITS;
- unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
-
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert(!qiov || bytes == qiov->size);
-
- waited = wait_serialising_requests(req);
- assert(!waited || !req->serialising);
- assert(req->overlap_offset <= offset);
- assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
-
- ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
-
- if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
- !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes &&
- qemu_iovec_is_zero(qiov)) {
- flags |= BDRV_REQ_ZERO_WRITE;
- if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
- flags |= BDRV_REQ_MAY_UNMAP;
- }
- }
-
- if (ret < 0) {
- /* Do nothing, write notifier decided to fail this request */
- } else if (flags & BDRV_REQ_ZERO_WRITE) {
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_ZERO);
- ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags);
- } else {
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV);
- ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
- }
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_DONE);
-
- if (ret == 0 && !bs->enable_write_cache) {
- ret = bdrv_co_flush(bs);
- }
-
- bdrv_set_dirty(bs, sector_num, nb_sectors);
-
- block_acct_highest_sector(&bs->stats, sector_num, nb_sectors);
-
- if (ret >= 0) {
- bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
- }
-
- return ret;
-}
-
-/*
- * Handle a write request in coroutine context
- */
-static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- BdrvTrackedRequest req;
- uint64_t align = bdrv_get_align(bs);
- uint8_t *head_buf = NULL;
- uint8_t *tail_buf = NULL;
- QEMUIOVector local_qiov;
- bool use_local_qiov = false;
- int ret;
-
- if (!bs->drv) {
- return -ENOMEDIUM;
- }
- if (bs->read_only) {
- return -EACCES;
- }
-
- ret = bdrv_check_byte_request(bs, offset, bytes);
- if (ret < 0) {
- return ret;
- }
-
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, bytes, true);
- }
-
- /*
- * Align write if necessary by performing a read-modify-write cycle.
- * Pad qiov with the read parts and be sure to have a tracked request not
- * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
- */
- tracked_request_begin(&req, bs, offset, bytes, true);
-
- if (offset & (align - 1)) {
- QEMUIOVector head_qiov;
- struct iovec head_iov;
-
- mark_request_serialising(&req, align);
- wait_serialising_requests(&req);
-
- head_buf = qemu_blockalign(bs, align);
- head_iov = (struct iovec) {
- .iov_base = head_buf,
- .iov_len = align,
- };
- qemu_iovec_init_external(&head_qiov, &head_iov, 1);
-
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_HEAD);
- ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align,
- align, &head_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
-
- qemu_iovec_init(&local_qiov, qiov->niov + 2);
- qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
-
- bytes += offset & (align - 1);
- offset = offset & ~(align - 1);
- }
-
- if ((offset + bytes) & (align - 1)) {
- QEMUIOVector tail_qiov;
- struct iovec tail_iov;
- size_t tail_bytes;
- bool waited;
-
- mark_request_serialising(&req, align);
- waited = wait_serialising_requests(&req);
- assert(!waited || !use_local_qiov);
-
- tail_buf = qemu_blockalign(bs, align);
- tail_iov = (struct iovec) {
- .iov_base = tail_buf,
- .iov_len = align,
- };
- qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
-
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_TAIL);
- ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align,
- align, &tail_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
-
- if (!use_local_qiov) {
- qemu_iovec_init(&local_qiov, qiov->niov + 1);
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
- }
-
- tail_bytes = (offset + bytes) & (align - 1);
- qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
-
- bytes = ROUND_UP(bytes, align);
- }
-
- if (use_local_qiov) {
- /* Local buffer may have non-zero data. */
- flags &= ~BDRV_REQ_ZERO_WRITE;
- }
- ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
- use_local_qiov ? &local_qiov : qiov,
- flags);
-
-fail:
- tracked_request_end(&req);
-
- if (use_local_qiov) {
- qemu_iovec_destroy(&local_qiov);
- }
- qemu_vfree(head_buf);
- qemu_vfree(tail_buf);
-
- return ret;
-}
-
-static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EINVAL;
- }
-
- return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
-}
-
-int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *qiov)
-{
- trace_bdrv_co_writev(bs, sector_num, nb_sectors);
-
- return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0);
-}
-
-int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- BdrvRequestFlags flags)
-{
- int ret;
-
- trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
-
- if (!(bs->open_flags & BDRV_O_UNMAP)) {
- flags &= ~BDRV_REQ_MAY_UNMAP;
- }
- if (bdrv_req_is_aligned(bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS)) {
- ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
- BDRV_REQ_ZERO_WRITE | flags);
- } else {
- uint8_t *buf;
- QEMUIOVector local_qiov;
- size_t bytes = nb_sectors << BDRV_SECTOR_BITS;
-
- buf = qemu_memalign(bdrv_opt_mem_align(bs), bytes);
- memset(buf, 0, bytes);
- qemu_iovec_init(&local_qiov, 1);
- qemu_iovec_add(&local_qiov, buf, bytes);
-
- ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, &local_qiov,
- BDRV_REQ_ZERO_WRITE | flags);
- qemu_vfree(buf);
- }
- return ret;
-}
-
/**
* Truncate file to 'offset' bytes (needed only for file protocols)
*/
@@ -4015,26 +2678,6 @@ int bdrv_get_flags(BlockDriverState *bs)
return bs->open_flags;
}
-int bdrv_flush_all(void)
-{
- BlockDriverState *bs = NULL;
- int result = 0;
-
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
- int ret;
-
- aio_context_acquire(aio_context);
- ret = bdrv_flush(bs);
- if (ret < 0 && !result) {
- result = ret;
- }
- aio_context_release(aio_context);
- }
-
- return result;
-}
-
int bdrv_has_zero_init_1(BlockDriverState *bs)
{
return 1;
@@ -4087,222 +2730,6 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
return false;
}
-typedef struct BdrvCoGetBlockStatusData {
- BlockDriverState *bs;
- BlockDriverState *base;
- int64_t sector_num;
- int nb_sectors;
- int *pnum;
- int64_t ret;
- bool done;
-} BdrvCoGetBlockStatusData;
-
-/*
- * Returns the allocation status of the specified sectors.
- * Drivers not implementing the functionality are assumed to not support
- * backing files, hence all their sectors are reported as allocated.
- *
- * If 'sector_num' is beyond the end of the disk image the return value is 0
- * and 'pnum' is set to 0.
- *
- * 'pnum' is set to the number of sectors (including and immediately following
- * the specified sector) that are known to be in the same
- * allocated/unallocated state.
- *
- * '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.
- */
-static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- int64_t total_sectors;
- int64_t n;
- int64_t ret, ret2;
-
- total_sectors = bdrv_nb_sectors(bs);
- if (total_sectors < 0) {
- return total_sectors;
- }
-
- if (sector_num >= total_sectors) {
- *pnum = 0;
- return 0;
- }
-
- n = total_sectors - sector_num;
- if (n < nb_sectors) {
- nb_sectors = n;
- }
-
- if (!bs->drv->bdrv_co_get_block_status) {
- *pnum = nb_sectors;
- ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
- if (bs->drv->protocol_name) {
- ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
- }
- return ret;
- }
-
- ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);
- if (ret < 0) {
- *pnum = 0;
- return ret;
- }
-
- if (ret & BDRV_BLOCK_RAW) {
- assert(ret & BDRV_BLOCK_OFFSET_VALID);
- return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
- *pnum, pnum);
- }
-
- if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
- ret |= BDRV_BLOCK_ALLOCATED;
- }
-
- if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
- if (bdrv_unallocated_blocks_are_zero(bs)) {
- ret |= BDRV_BLOCK_ZERO;
- } else if (bs->backing_hd) {
- BlockDriverState *bs2 = bs->backing_hd;
- int64_t nb_sectors2 = bdrv_nb_sectors(bs2);
- if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {
- ret |= BDRV_BLOCK_ZERO;
- }
- }
- }
-
- if (bs->file &&
- (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
- (ret & BDRV_BLOCK_OFFSET_VALID)) {
- int file_pnum;
-
- ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
- *pnum, &file_pnum);
- if (ret2 >= 0) {
- /* Ignore errors. This is just providing extra information, it
- * is useful but not necessary.
- */
- if (!file_pnum) {
- /* !file_pnum indicates an offset at or beyond the EOF; it is
- * perfectly valid for the format block driver to point to such
- * offsets, so catch it and mark everything as zero */
- ret |= BDRV_BLOCK_ZERO;
- } else {
- /* Limit request to the range reported by the protocol driver */
- *pnum = file_pnum;
- ret |= (ret2 & BDRV_BLOCK_ZERO);
- }
- }
- }
-
- return ret;
-}
-
-/* Coroutine wrapper for bdrv_get_block_status() */
-static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque)
-{
- BdrvCoGetBlockStatusData *data = opaque;
- BlockDriverState *bs = data->bs;
-
- data->ret = bdrv_co_get_block_status(bs, data->sector_num, data->nb_sectors,
- data->pnum);
- data->done = true;
-}
-
-/*
- * Synchronous wrapper around bdrv_co_get_block_status().
- *
- * See bdrv_co_get_block_status() for details.
- */
-int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- Coroutine *co;
- BdrvCoGetBlockStatusData data = {
- .bs = bs,
- .sector_num = sector_num,
- .nb_sectors = nb_sectors,
- .pnum = pnum,
- .done = false,
- };
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_get_block_status_co_entry(&data);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_get_block_status_co_entry);
- qemu_coroutine_enter(co, &data);
- while (!data.done) {
- aio_poll(aio_context, true);
- }
- }
- return data.ret;
-}
-
-int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum);
- if (ret < 0) {
- return ret;
- }
- return !!(ret & BDRV_BLOCK_ALLOCATED);
-}
-
-/*
- * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
- *
- * Return true if the given sector is allocated in any image between
- * BASE and TOP (inclusive). BASE can be NULL to check if the given
- * sector is allocated in any image of the chain. Return false otherwise.
- *
- * 'pnum' is set to the number of sectors (including and immediately following
- * the specified sector) that are known to be in the same
- * allocated/unallocated state.
- *
- */
-int bdrv_is_allocated_above(BlockDriverState *top,
- BlockDriverState *base,
- int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- BlockDriverState *intermediate;
- int ret, n = nb_sectors;
-
- intermediate = top;
- while (intermediate && intermediate != base) {
- int pnum_inter;
- ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors,
- &pnum_inter);
- if (ret < 0) {
- return ret;
- } else if (ret) {
- *pnum = pnum_inter;
- return 1;
- }
-
- /*
- * [sector_num, nb_sectors] is unallocated on top but intermediate
- * might have
- *
- * [sector_num+x, nr_sectors] allocated.
- */
- if (n > pnum_inter &&
- (intermediate == top ||
- sector_num + pnum_inter < intermediate->total_sectors)) {
- n = pnum_inter;
- }
-
- intermediate = intermediate->backing_hd;
- }
-
- *pnum = n;
- return 0;
-}
-
const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
{
if (bs->backing_hd && bs->backing_hd->encrypted)
@@ -4319,28 +2746,6 @@ void bdrv_get_backing_filename(BlockDriverState *bs,
pstrcpy(filename, filename_size, bs->backing_file);
}
-int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
-{
- BlockDriver *drv = bs->drv;
- int ret;
-
- if (!drv) {
- return -ENOMEDIUM;
- }
- if (!drv->bdrv_write_compressed) {
- return -ENOTSUP;
- }
- ret = bdrv_check_request(bs, sector_num, nb_sectors);
- if (ret < 0) {
- return ret;
- }
-
- assert(QLIST_EMPTY(&bs->dirty_bitmaps));
-
- return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
-}
-
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BlockDriver *drv = bs->drv;
@@ -4361,47 +2766,6 @@ ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
return NULL;
}
-int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
- int64_t pos, int size)
-{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *) buf,
- .iov_len = size,
- };
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_writev_vmstate(bs, &qiov, pos);
-}
-
-int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
-{
- BlockDriver *drv = bs->drv;
-
- if (!drv) {
- return -ENOMEDIUM;
- } else if (drv->bdrv_save_vmstate) {
- return drv->bdrv_save_vmstate(bs, qiov, pos);
- } else if (bs->file) {
- return bdrv_writev_vmstate(bs->file, qiov, pos);
- }
-
- return -ENOTSUP;
-}
-
-int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
- int64_t pos, int size)
-{
- BlockDriver *drv = bs->drv;
- if (!drv)
- return -ENOMEDIUM;
- if (drv->bdrv_load_vmstate)
- return drv->bdrv_load_vmstate(bs, buf, pos, size);
- if (bs->file)
- return bdrv_load_vmstate(bs->file, buf, pos, size);
- return -ENOTSUP;
-}
-
void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
{
if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
@@ -4548,477 +2912,6 @@ int bdrv_get_backing_file_depth(BlockDriverState *bs)
return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
}
-/**************************************************************/
-/* async I/Os */
-
-BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
-
- return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
- cb, opaque, false);
-}
-
-BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
-
- return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
- cb, opaque, true);
-}
-
-BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BdrvRequestFlags flags,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque);
-
- return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors,
- BDRV_REQ_ZERO_WRITE | flags,
- cb, opaque, true);
-}
-
-
-typedef struct MultiwriteCB {
- int error;
- int num_requests;
- int num_callbacks;
- struct {
- BlockCompletionFunc *cb;
- void *opaque;
- QEMUIOVector *free_qiov;
- } callbacks[];
-} MultiwriteCB;
-
-static void multiwrite_user_cb(MultiwriteCB *mcb)
-{
- int i;
-
- for (i = 0; i < mcb->num_callbacks; i++) {
- mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
- if (mcb->callbacks[i].free_qiov) {
- qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
- }
- g_free(mcb->callbacks[i].free_qiov);
- }
-}
-
-static void multiwrite_cb(void *opaque, int ret)
-{
- MultiwriteCB *mcb = opaque;
-
- trace_multiwrite_cb(mcb, ret);
-
- if (ret < 0 && !mcb->error) {
- mcb->error = ret;
- }
-
- mcb->num_requests--;
- if (mcb->num_requests == 0) {
- multiwrite_user_cb(mcb);
- g_free(mcb);
- }
-}
-
-static int multiwrite_req_compare(const void *a, const void *b)
-{
- const BlockRequest *req1 = a, *req2 = b;
-
- /*
- * Note that we can't simply subtract req2->sector from req1->sector
- * here as that could overflow the return value.
- */
- if (req1->sector > req2->sector) {
- return 1;
- } else if (req1->sector < req2->sector) {
- return -1;
- } else {
- return 0;
- }
-}
-
-/*
- * Takes a bunch of requests and tries to merge them. Returns the number of
- * requests that remain after merging.
- */
-static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
- int num_reqs, MultiwriteCB *mcb)
-{
- int i, outidx;
-
- // Sort requests by start sector
- qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
-
- // Check if adjacent requests touch the same clusters. If so, combine them,
- // filling up gaps with zero sectors.
- outidx = 0;
- for (i = 1; i < num_reqs; i++) {
- int merge = 0;
- int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
-
- // Handle exactly sequential writes and overlapping writes.
- if (reqs[i].sector <= oldreq_last) {
- merge = 1;
- }
-
- if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
- merge = 0;
- }
-
- if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors +
- reqs[i].nb_sectors > bs->bl.max_transfer_length) {
- merge = 0;
- }
-
- if (merge) {
- size_t size;
- QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
- qemu_iovec_init(qiov,
- reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
-
- // Add the first request to the merged one. If the requests are
- // overlapping, drop the last sectors of the first request.
- size = (reqs[i].sector - reqs[outidx].sector) << 9;
- qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size);
-
- // We should need to add any zeros between the two requests
- assert (reqs[i].sector <= oldreq_last);
-
- // Add the second request
- qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size);
-
- // Add tail of first request, if necessary
- if (qiov->size < reqs[outidx].qiov->size) {
- qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size,
- reqs[outidx].qiov->size - qiov->size);
- }
-
- reqs[outidx].nb_sectors = qiov->size >> 9;
- reqs[outidx].qiov = qiov;
-
- mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
- } else {
- outidx++;
- reqs[outidx].sector = reqs[i].sector;
- reqs[outidx].nb_sectors = reqs[i].nb_sectors;
- reqs[outidx].qiov = reqs[i].qiov;
- }
- }
-
- block_acct_merge_done(&bs->stats, BLOCK_ACCT_WRITE, num_reqs - outidx - 1);
-
- return outidx + 1;
-}
-
-/*
- * Submit multiple AIO write requests at once.
- *
- * On success, the function returns 0 and all requests in the reqs array have
- * been submitted. In error case this function returns -1, and any of the
- * requests may or may not be submitted yet. In particular, this means that the
- * callback will be called for some of the requests, for others it won't. The
- * caller must check the error field of the BlockRequest to wait for the right
- * callbacks (if error != 0, no callback will be called).
- *
- * The implementation may modify the contents of the reqs array, e.g. to merge
- * requests. However, the fields opaque and error are left unmodified as they
- * are used to signal failure for a single request to the caller.
- */
-int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
-{
- MultiwriteCB *mcb;
- int i;
-
- /* don't submit writes if we don't have a medium */
- if (bs->drv == NULL) {
- for (i = 0; i < num_reqs; i++) {
- reqs[i].error = -ENOMEDIUM;
- }
- return -1;
- }
-
- if (num_reqs == 0) {
- return 0;
- }
-
- // Create MultiwriteCB structure
- mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
- mcb->num_requests = 0;
- mcb->num_callbacks = num_reqs;
-
- for (i = 0; i < num_reqs; i++) {
- mcb->callbacks[i].cb = reqs[i].cb;
- mcb->callbacks[i].opaque = reqs[i].opaque;
- }
-
- // Check for mergable requests
- num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
-
- trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
-
- /* Run the aio requests. */
- mcb->num_requests = num_reqs;
- for (i = 0; i < num_reqs; i++) {
- bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov,
- reqs[i].nb_sectors, reqs[i].flags,
- multiwrite_cb, mcb,
- true);
- }
-
- return 0;
-}
-
-void bdrv_aio_cancel(BlockAIOCB *acb)
-{
- qemu_aio_ref(acb);
- bdrv_aio_cancel_async(acb);
- while (acb->refcnt > 1) {
- if (acb->aiocb_info->get_aio_context) {
- aio_poll(acb->aiocb_info->get_aio_context(acb), true);
- } else if (acb->bs) {
- aio_poll(bdrv_get_aio_context(acb->bs), true);
- } else {
- abort();
- }
- }
- qemu_aio_unref(acb);
-}
-
-/* Async version of aio cancel. The caller is not blocked if the acb implements
- * cancel_async, otherwise we do nothing and let the request normally complete.
- * In either case the completion callback must be called. */
-void bdrv_aio_cancel_async(BlockAIOCB *acb)
-{
- if (acb->aiocb_info->cancel_async) {
- acb->aiocb_info->cancel_async(acb);
- }
-}
-
-/**************************************************************/
-/* async block device emulation */
-
-typedef struct BlockAIOCBSync {
- BlockAIOCB common;
- QEMUBH *bh;
- int ret;
- /* vector translation state */
- QEMUIOVector *qiov;
- uint8_t *bounce;
- int is_write;
-} BlockAIOCBSync;
-
-static const AIOCBInfo bdrv_em_aiocb_info = {
- .aiocb_size = sizeof(BlockAIOCBSync),
-};
-
-static void bdrv_aio_bh_cb(void *opaque)
-{
- BlockAIOCBSync *acb = opaque;
-
- if (!acb->is_write && acb->ret >= 0) {
- qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
- }
- qemu_vfree(acb->bounce);
- acb->common.cb(acb->common.opaque, acb->ret);
- qemu_bh_delete(acb->bh);
- acb->bh = NULL;
- qemu_aio_unref(acb);
-}
-
-static BlockAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BlockCompletionFunc *cb,
- void *opaque,
- int is_write)
-
-{
- BlockAIOCBSync *acb;
-
- acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque);
- acb->is_write = is_write;
- acb->qiov = qiov;
- acb->bounce = qemu_try_blockalign(bs, qiov->size);
- acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb);
-
- if (acb->bounce == NULL) {
- acb->ret = -ENOMEM;
- } else if (is_write) {
- qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
- acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
- } else {
- acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
- }
-
- qemu_bh_schedule(acb->bh);
-
- return &acb->common;
-}
-
-static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
-}
-
-static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
-}
-
-
-typedef struct BlockAIOCBCoroutine {
- BlockAIOCB common;
- BlockRequest req;
- bool is_write;
- bool need_bh;
- bool *done;
- QEMUBH* bh;
-} BlockAIOCBCoroutine;
-
-static const AIOCBInfo bdrv_em_co_aiocb_info = {
- .aiocb_size = sizeof(BlockAIOCBCoroutine),
-};
-
-static void bdrv_co_complete(BlockAIOCBCoroutine *acb)
-{
- if (!acb->need_bh) {
- acb->common.cb(acb->common.opaque, acb->req.error);
- qemu_aio_unref(acb);
- }
-}
-
-static void bdrv_co_em_bh(void *opaque)
-{
- BlockAIOCBCoroutine *acb = opaque;
-
- assert(!acb->need_bh);
- qemu_bh_delete(acb->bh);
- bdrv_co_complete(acb);
-}
-
-static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb)
-{
- acb->need_bh = false;
- if (acb->req.error != -EINPROGRESS) {
- BlockDriverState *bs = acb->common.bs;
-
- acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
- qemu_bh_schedule(acb->bh);
- }
-}
-
-/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
-static void coroutine_fn bdrv_co_do_rw(void *opaque)
-{
- BlockAIOCBCoroutine *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
-
- if (!acb->is_write) {
- acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
- acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
- } else {
- acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
- acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
- }
-
- bdrv_co_complete(acb);
-}
-
-static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BdrvRequestFlags flags,
- BlockCompletionFunc *cb,
- void *opaque,
- bool is_write)
-{
- Coroutine *co;
- BlockAIOCBCoroutine *acb;
-
- acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
- acb->need_bh = true;
- acb->req.error = -EINPROGRESS;
- acb->req.sector = sector_num;
- acb->req.nb_sectors = nb_sectors;
- acb->req.qiov = qiov;
- acb->req.flags = flags;
- acb->is_write = is_write;
-
- co = qemu_coroutine_create(bdrv_co_do_rw);
- qemu_coroutine_enter(co, acb);
-
- bdrv_co_maybe_schedule_bh(acb);
- return &acb->common;
-}
-
-static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
-{
- BlockAIOCBCoroutine *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
-
- acb->req.error = bdrv_co_flush(bs);
- bdrv_co_complete(acb);
-}
-
-BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_flush(bs, opaque);
-
- Coroutine *co;
- BlockAIOCBCoroutine *acb;
-
- acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
- acb->need_bh = true;
- acb->req.error = -EINPROGRESS;
-
- co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
- qemu_coroutine_enter(co, acb);
-
- bdrv_co_maybe_schedule_bh(acb);
- return &acb->common;
-}
-
-static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
-{
- BlockAIOCBCoroutine *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
-
- acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
- bdrv_co_complete(acb);
-}
-
-BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- Coroutine *co;
- BlockAIOCBCoroutine *acb;
-
- trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
-
- acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
- acb->need_bh = true;
- acb->req.error = -EINPROGRESS;
- acb->req.sector = sector_num;
- acb->req.nb_sectors = nb_sectors;
- co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
- qemu_coroutine_enter(co, acb);
-
- bdrv_co_maybe_schedule_bh(acb);
- return &acb->common;
-}
-
void bdrv_init(void)
{
module_call_init(MODULE_INIT_BLOCK);
@@ -5030,161 +2923,6 @@ void bdrv_init_with_whitelist(void)
bdrv_init();
}
-void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
- BlockCompletionFunc *cb, void *opaque)
-{
- BlockAIOCB *acb;
-
- acb = g_slice_alloc(aiocb_info->aiocb_size);
- acb->aiocb_info = aiocb_info;
- acb->bs = bs;
- acb->cb = cb;
- acb->opaque = opaque;
- acb->refcnt = 1;
- return acb;
-}
-
-void qemu_aio_ref(void *p)
-{
- BlockAIOCB *acb = p;
- acb->refcnt++;
-}
-
-void qemu_aio_unref(void *p)
-{
- BlockAIOCB *acb = p;
- assert(acb->refcnt > 0);
- if (--acb->refcnt == 0) {
- g_slice_free1(acb->aiocb_info->aiocb_size, acb);
- }
-}
-
-/**************************************************************/
-/* Coroutine block device emulation */
-
-typedef struct CoroutineIOCompletion {
- Coroutine *coroutine;
- int ret;
-} CoroutineIOCompletion;
-
-static void bdrv_co_io_em_complete(void *opaque, int ret)
-{
- CoroutineIOCompletion *co = opaque;
-
- co->ret = ret;
- qemu_coroutine_enter(co->coroutine, NULL);
-}
-
-static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *iov,
- bool is_write)
-{
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
- BlockAIOCB *acb;
-
- if (is_write) {
- acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
- bdrv_co_io_em_complete, &co);
- } else {
- acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
- bdrv_co_io_em_complete, &co);
- }
-
- trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
- if (!acb) {
- return -EIO;
- }
- qemu_coroutine_yield();
-
- return co.ret;
-}
-
-static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov)
-{
- return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false);
-}
-
-static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov)
-{
- return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true);
-}
-
-static void coroutine_fn bdrv_flush_co_entry(void *opaque)
-{
- RwCo *rwco = opaque;
-
- rwco->ret = bdrv_co_flush(rwco->bs);
-}
-
-int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
-{
- int ret;
-
- if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
- return 0;
- }
-
- /* Write back cached data to the OS even with cache=unsafe */
- BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
- if (bs->drv->bdrv_co_flush_to_os) {
- ret = bs->drv->bdrv_co_flush_to_os(bs);
- if (ret < 0) {
- return ret;
- }
- }
-
- /* But don't actually force it to the disk with cache=unsafe */
- if (bs->open_flags & BDRV_O_NO_FLUSH) {
- goto flush_parent;
- }
-
- BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
- if (bs->drv->bdrv_co_flush_to_disk) {
- ret = bs->drv->bdrv_co_flush_to_disk(bs);
- } else if (bs->drv->bdrv_aio_flush) {
- BlockAIOCB *acb;
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
-
- acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
- if (acb == NULL) {
- ret = -EIO;
- } else {
- qemu_coroutine_yield();
- ret = co.ret;
- }
- } else {
- /*
- * Some block drivers always operate in either writethrough or unsafe
- * mode and don't support bdrv_flush therefore. Usually qemu doesn't
- * know how the server works (because the behaviour is hardcoded or
- * depends on server-side configuration), so we can't ensure that
- * everything is safe on disk. Returning an error doesn't work because
- * that would break guests even if the server operates in writethrough
- * mode.
- *
- * Let's hope the user knows what he's doing.
- */
- ret = 0;
- }
- if (ret < 0) {
- return ret;
- }
-
- /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
- * in the case of cache=unsafe, so there are no useless flushes.
- */
-flush_parent:
- return bdrv_co_flush(bs->file);
-}
-
void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
{
Error *local_err = NULL;
@@ -5234,143 +2972,6 @@ void bdrv_invalidate_cache_all(Error **errp)
}
}
-int bdrv_flush(BlockDriverState *bs)
-{
- Coroutine *co;
- RwCo rwco = {
- .bs = bs,
- .ret = NOT_DONE,
- };
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_flush_co_entry(&rwco);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_flush_co_entry);
- qemu_coroutine_enter(co, &rwco);
- while (rwco.ret == NOT_DONE) {
- aio_poll(aio_context, true);
- }
- }
-
- return rwco.ret;
-}
-
-typedef struct DiscardCo {
- BlockDriverState *bs;
- int64_t sector_num;
- int nb_sectors;
- int ret;
-} DiscardCo;
-static void coroutine_fn bdrv_discard_co_entry(void *opaque)
-{
- DiscardCo *rwco = opaque;
-
- rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
-}
-
-int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors)
-{
- int max_discard, ret;
-
- if (!bs->drv) {
- return -ENOMEDIUM;
- }
-
- ret = bdrv_check_request(bs, sector_num, nb_sectors);
- if (ret < 0) {
- return ret;
- } else if (bs->read_only) {
- return -EROFS;
- }
-
- bdrv_reset_dirty(bs, sector_num, nb_sectors);
-
- /* Do nothing if disabled. */
- if (!(bs->open_flags & BDRV_O_UNMAP)) {
- return 0;
- }
-
- if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) {
- return 0;
- }
-
- max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
- while (nb_sectors > 0) {
- int ret;
- int num = nb_sectors;
-
- /* align request */
- if (bs->bl.discard_alignment &&
- num >= bs->bl.discard_alignment &&
- sector_num % bs->bl.discard_alignment) {
- if (num > bs->bl.discard_alignment) {
- num = bs->bl.discard_alignment;
- }
- num -= sector_num % bs->bl.discard_alignment;
- }
-
- /* limit request size */
- if (num > max_discard) {
- num = max_discard;
- }
-
- if (bs->drv->bdrv_co_discard) {
- ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
- } else {
- BlockAIOCB *acb;
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
-
- acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
- bdrv_co_io_em_complete, &co);
- if (acb == NULL) {
- return -EIO;
- } else {
- qemu_coroutine_yield();
- ret = co.ret;
- }
- }
- if (ret && ret != -ENOTSUP) {
- return ret;
- }
-
- sector_num += num;
- nb_sectors -= num;
- }
- return 0;
-}
-
-int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
-{
- Coroutine *co;
- DiscardCo rwco = {
- .bs = bs,
- .sector_num = sector_num,
- .nb_sectors = nb_sectors,
- .ret = NOT_DONE,
- };
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_discard_co_entry(&rwco);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_discard_co_entry);
- qemu_coroutine_enter(co, &rwco);
- while (rwco.ret == NOT_DONE) {
- aio_poll(aio_context, true);
- }
- }
-
- return rwco.ret;
-}
-
/**************************************************************/
/* removable device support */
@@ -5436,87 +3037,11 @@ void bdrv_lock_medium(BlockDriverState *bs, bool locked)
}
}
-/* needed for generic scsi interface */
-
-int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
-{
- BlockDriver *drv = bs->drv;
-
- if (drv && drv->bdrv_ioctl)
- return drv->bdrv_ioctl(bs, req, buf);
- return -ENOTSUP;
-}
-
-BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
- unsigned long int req, void *buf,
- BlockCompletionFunc *cb, void *opaque)
-{
- BlockDriver *drv = bs->drv;
-
- if (drv && drv->bdrv_aio_ioctl)
- return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
- return NULL;
-}
-
void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
{
bs->guest_block_size = align;
}
-void *qemu_blockalign(BlockDriverState *bs, size_t size)
-{
- return qemu_memalign(bdrv_opt_mem_align(bs), size);
-}
-
-void *qemu_blockalign0(BlockDriverState *bs, size_t size)
-{
- return memset(qemu_blockalign(bs, size), 0, size);
-}
-
-void *qemu_try_blockalign(BlockDriverState *bs, size_t size)
-{
- size_t align = bdrv_opt_mem_align(bs);
-
- /* Ensure that NULL is never returned on success */
- assert(align > 0);
- if (size == 0) {
- size = align;
- }
-
- return qemu_try_memalign(align, size);
-}
-
-void *qemu_try_blockalign0(BlockDriverState *bs, size_t size)
-{
- void *mem = qemu_try_blockalign(bs, size);
-
- if (mem) {
- memset(mem, 0, size);
- }
-
- return mem;
-}
-
-/*
- * Check if all memory in this vector is sector aligned.
- */
-bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
-{
- int i;
- size_t alignment = bdrv_opt_mem_align(bs);
-
- for (i = 0; i < qiov->niov; i++) {
- if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
- return false;
- }
- if (qiov->iov[i].iov_len % alignment) {
- return false;
- }
- }
-
- return true;
-}
-
BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
{
BdrvDirtyBitmap *bm;
@@ -5787,8 +3312,8 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap)
hbitmap_reset(bitmap->bitmap, 0, bitmap->size);
}
-static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
- int nr_sectors)
+void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
+ int nr_sectors)
{
BdrvDirtyBitmap *bitmap;
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
@@ -5799,8 +3324,8 @@ static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
}
}
-static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
- int nr_sectors)
+void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
+ int nr_sectors)
{
BdrvDirtyBitmap *bitmap;
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
@@ -6238,12 +3763,6 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
abort();
}
-void bdrv_add_before_write_notifier(BlockDriverState *bs,
- NotifierWithReturn *notifier)
-{
- notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
-}
-
int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
BlockDriverAmendStatusCB *status_cb)
{
@@ -6344,36 +3863,6 @@ out:
return to_replace_bs;
}
-void bdrv_io_plug(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_io_plug) {
- drv->bdrv_io_plug(bs);
- } else if (bs->file) {
- bdrv_io_plug(bs->file);
- }
-}
-
-void bdrv_io_unplug(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_io_unplug) {
- drv->bdrv_io_unplug(bs);
- } else if (bs->file) {
- bdrv_io_unplug(bs->file);
- }
-}
-
-void bdrv_flush_io_queue(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_flush_io_queue) {
- drv->bdrv_flush_io_queue(bs);
- } else if (bs->file) {
- bdrv_flush_io_queue(bs->file);
- }
-}
-
static bool append_open_options(QDict *d, BlockDriverState *bs)
{
const QDictEntry *entry;
diff --git a/block/Makefile.objs b/block/Makefile.objs
index db2933e..66c3690 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -9,7 +9,7 @@ block-obj-y += block-backend.o snapshot.o qapi.o
block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
block-obj-$(CONFIG_POSIX) += raw-posix.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
-block-obj-y += null.o mirror.o
+block-obj-y += null.o mirror.o io.o
block-obj-y += nbd.o nbd-client.o sheepdog.o
block-obj-$(CONFIG_LIBISCSI) += iscsi.o
diff --git a/include/block/block_int.h b/include/block/block_int.h
index e0d5561..db29b74 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -439,6 +439,14 @@ extern BlockDriver bdrv_file;
extern BlockDriver bdrv_raw;
extern BlockDriver bdrv_qcow2;
+/**
+ * bdrv_setup_io_funcs:
+ *
+ * Prepare a #BlockDriver for I/O request processing by populating
+ * unimplemented coroutine and AIO interfaces with generic wrapper functions
+ * that fall back to implemented interfaces.
+ */
+void bdrv_setup_io_funcs(BlockDriver *bdrv);
int get_tmp_filename(char *filename, int size);
BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
@@ -626,4 +634,8 @@ bool blk_dev_is_tray_open(BlockBackend *blk);
bool blk_dev_is_medium_locked(BlockBackend *blk);
void blk_dev_resize_cb(BlockBackend *blk);
+void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
+void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
+ int nr_sectors);
+
#endif /* BLOCK_INT_H */
--
2.1.0
^ permalink raw reply related [flat|nested] 6+ messages in thread