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Diffstat (limited to 'block.c')
-rw-r--r--block.c1024
1 files changed, 778 insertions, 246 deletions
diff --git a/block.c b/block.c
index 64e7d220c6..cb21a5fa61 100644
--- a/block.c
+++ b/block.c
@@ -32,6 +32,7 @@
#include "sysemu/sysemu.h"
#include "qemu/notify.h"
#include "block/coroutine.h"
+#include "block/qapi.h"
#include "qmp-commands.h"
#include "qemu/timer.h"
@@ -69,11 +70,11 @@ static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
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_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+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_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
int64_t sector_num,
@@ -90,6 +91,9 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
QTAILQ_HEAD_INITIALIZER(bdrv_states);
+static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
+ QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
+
static QLIST_HEAD(, BlockDriver) bdrv_drivers =
QLIST_HEAD_INITIALIZER(bdrv_drivers);
@@ -188,7 +192,7 @@ void bdrv_io_limits_enable(BlockDriverState *bs)
* @is_write: is the IO a write
*/
static void bdrv_io_limits_intercept(BlockDriverState *bs,
- int nb_sectors,
+ unsigned int bytes,
bool is_write)
{
/* does this io must wait */
@@ -201,9 +205,8 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs,
}
/* the IO will be executed, do the accounting */
- throttle_account(&bs->throttle_state,
- is_write,
- nb_sectors * BDRV_SECTOR_SIZE);
+ 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)) {
@@ -214,6 +217,16 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs,
qemu_co_queue_next(&bs->throttled_reqs[is_write]);
}
+size_t bdrv_opt_mem_align(BlockDriverState *bs)
+{
+ if (!bs || !bs->drv) {
+ /* 4k should be on the safe side */
+ return 4096;
+ }
+
+ return bs->bl.opt_mem_alignment;
+}
+
/* check if the path starts with "<protocol>:" */
static int path_has_protocol(const char *path)
{
@@ -327,7 +340,7 @@ BlockDriverState *bdrv_new(const char *device_name)
QLIST_INIT(&bs->dirty_bitmaps);
pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
if (device_name[0] != '\0') {
- QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
+ QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list);
}
bdrv_iostatus_disable(bs);
notifier_list_init(&bs->close_notifiers);
@@ -479,6 +492,43 @@ int bdrv_create_file(const char* filename, QEMUOptionParameter *options,
return ret;
}
+int bdrv_refresh_limits(BlockDriverState *bs)
+{
+ BlockDriver *drv = bs->drv;
+
+ memset(&bs->bl, 0, sizeof(bs->bl));
+
+ if (!drv) {
+ return 0;
+ }
+
+ /* Take some limits from the children as a default */
+ if (bs->file) {
+ bdrv_refresh_limits(bs->file);
+ bs->bl.opt_transfer_length = bs->file->bl.opt_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);
+ bs->bl.opt_transfer_length =
+ MAX(bs->bl.opt_transfer_length,
+ bs->backing_hd->bl.opt_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) {
+ return drv->bdrv_refresh_limits(bs);
+ }
+
+ return 0;
+}
+
/*
* Create a uniquely-named empty temporary file.
* Return 0 upon success, otherwise a negative errno value.
@@ -732,6 +782,33 @@ static int bdrv_open_flags(BlockDriverState *bs, int flags)
return open_flags;
}
+static int bdrv_assign_node_name(BlockDriverState *bs,
+ const char *node_name,
+ Error **errp)
+{
+ if (!node_name) {
+ return 0;
+ }
+
+ /* empty string node name is invalid */
+ if (node_name[0] == '\0') {
+ error_setg(errp, "Empty node name");
+ return -EINVAL;
+ }
+
+ /* takes care of avoiding duplicates node names */
+ if (bdrv_find_node(node_name)) {
+ error_setg(errp, "Duplicate node name");
+ return -EINVAL;
+ }
+
+ /* copy node name into the bs and insert it into the graph list */
+ pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
+ QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
+
+ return 0;
+}
+
/*
* Common part for opening disk images and files
*
@@ -742,6 +819,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
{
int ret, open_flags;
const char *filename;
+ const char *node_name = NULL;
Error *local_err = NULL;
assert(drv != NULL);
@@ -756,6 +834,13 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
+ node_name = qdict_get_try_str(options, "node-name");
+ ret = bdrv_assign_node_name(bs, node_name, errp);
+ if (ret < 0) {
+ return ret;
+ }
+ qdict_del(options, "node-name");
+
/* bdrv_open() with directly using a protocol as drv. This layer is already
* opened, so assign it to bs (while file becomes a closed BlockDriverState)
* and return immediately. */
@@ -765,7 +850,8 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
}
bs->open_flags = flags;
- bs->buffer_alignment = 512;
+ bs->guest_block_size = 512;
+ bs->request_alignment = 512;
bs->zero_beyond_eof = true;
open_flags = bdrv_open_flags(bs, flags);
bs->read_only = !(open_flags & BDRV_O_RDWR);
@@ -833,6 +919,10 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
goto free_and_fail;
}
+ bdrv_refresh_limits(bs);
+ assert(bdrv_opt_mem_align(bs) != 0);
+ assert(bs->request_alignment != 0);
+
#ifndef _WIN32
if (bs->is_temporary) {
assert(bs->filename[0] != '\0');
@@ -858,9 +948,10 @@ free_and_fail:
* dictionary, it needs to use QINCREF() before calling bdrv_file_open.
*/
int bdrv_file_open(BlockDriverState **pbs, const char *filename,
- QDict *options, int flags, Error **errp)
+ const char *reference, QDict *options, int flags,
+ Error **errp)
{
- BlockDriverState *bs;
+ BlockDriverState *bs = NULL;
BlockDriver *drv;
const char *drvname;
bool allow_protocol_prefix = false;
@@ -872,6 +963,24 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
options = qdict_new();
}
+ if (reference) {
+ if (filename || qdict_size(options)) {
+ error_setg(errp, "Cannot reference an existing block device with "
+ "additional options or a new filename");
+ return -EINVAL;
+ }
+ QDECREF(options);
+
+ bs = bdrv_find(reference);
+ if (!bs) {
+ error_setg(errp, "Cannot find block device '%s'", reference);
+ return -ENODEV;
+ }
+ bdrv_ref(bs);
+ *pbs = bs;
+ return 0;
+ }
+
bs = bdrv_new("");
bs->options = options;
options = qdict_clone_shallow(options);
@@ -929,14 +1038,19 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
goto fail;
}
- ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
+ if (!drv->bdrv_file_open) {
+ ret = bdrv_open(bs, filename, options, flags, drv, &local_err);
+ options = NULL;
+ } else {
+ ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
+ }
if (ret < 0) {
error_propagate(errp, local_err);
goto fail;
}
/* Check if any unknown options were used */
- if (qdict_size(options) != 0) {
+ if (options && (qdict_size(options) != 0)) {
const QDictEntry *entry = qdict_first(options);
error_setg(errp, "Block protocol '%s' doesn't support the option '%s'",
drv->format_name, entry->key);
@@ -1016,12 +1130,92 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
error_free(local_err);
return ret;
}
- pstrcpy(bs->backing_file, sizeof(bs->backing_file),
- bs->backing_hd->file->filename);
+
+ if (bs->backing_hd->file) {
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+ bs->backing_hd->file->filename);
+ }
+
+ /* Recalculate the BlockLimits with the backing file */
+ bdrv_refresh_limits(bs);
+
return 0;
}
/*
+ * Opens a disk image whose options are given as BlockdevRef in another block
+ * device's options.
+ *
+ * If force_raw is true, bdrv_file_open() will be used, thereby preventing any
+ * image format auto-detection. If it is false and a filename is given,
+ * bdrv_open() will be used for auto-detection.
+ *
+ * If allow_none is true, no image will be opened if filename is false and no
+ * BlockdevRef is given. *pbs will remain unchanged and 0 will be returned.
+ *
+ * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
+ * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
+ * itself, all options starting with "${bdref_key}." are considered part of the
+ * BlockdevRef.
+ *
+ * The BlockdevRef will be removed from the options QDict.
+ */
+int bdrv_open_image(BlockDriverState **pbs, const char *filename,
+ QDict *options, const char *bdref_key, int flags,
+ bool force_raw, bool allow_none, Error **errp)
+{
+ QDict *image_options;
+ int ret;
+ char *bdref_key_dot;
+ const char *reference;
+
+ bdref_key_dot = g_strdup_printf("%s.", bdref_key);
+ qdict_extract_subqdict(options, &image_options, bdref_key_dot);
+ g_free(bdref_key_dot);
+
+ reference = qdict_get_try_str(options, bdref_key);
+ if (!filename && !reference && !qdict_size(image_options)) {
+ if (allow_none) {
+ ret = 0;
+ } else {
+ error_setg(errp, "A block device must be specified for \"%s\"",
+ bdref_key);
+ ret = -EINVAL;
+ }
+ goto done;
+ }
+
+ if (filename && !force_raw) {
+ /* If a filename is given and the block driver should be detected
+ automatically (instead of using none), use bdrv_open() in order to do
+ that auto-detection. */
+ BlockDriverState *bs;
+
+ if (reference) {
+ error_setg(errp, "Cannot reference an existing block device while "
+ "giving a filename");
+ ret = -EINVAL;
+ goto done;
+ }
+
+ bs = bdrv_new("");
+ ret = bdrv_open(bs, filename, image_options, flags, NULL, errp);
+ if (ret < 0) {
+ bdrv_unref(bs);
+ } else {
+ *pbs = bs;
+ }
+ } else {
+ ret = bdrv_file_open(pbs, filename, reference, image_options, flags,
+ errp);
+ }
+
+done:
+ qdict_del(options, bdref_key);
+ return ret;
+}
+
+/*
* Opens a disk image (raw, qcow2, vmdk, ...)
*
* options is a QDict of options to pass to the block drivers, or NULL for an
@@ -1036,7 +1230,6 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
/* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
char tmp_filename[PATH_MAX + 1];
BlockDriverState *file = NULL;
- QDict *file_options = NULL;
const char *drvname;
Error *local_err = NULL;
@@ -1122,10 +1315,9 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
flags |= BDRV_O_ALLOW_RDWR;
}
- qdict_extract_subqdict(options, &file_options, "file.");
-
- ret = bdrv_file_open(&file, filename, file_options,
- bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err);
+ ret = bdrv_open_image(&file, filename, options, "file",
+ bdrv_open_flags(bs, flags | BDRV_O_UNMAP), true, true,
+ &local_err);
if (ret < 0) {
goto fail;
}
@@ -1143,7 +1335,13 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
}
if (!drv) {
- ret = find_image_format(file, filename, &drv, &local_err);
+ if (file) {
+ ret = find_image_format(file, filename, &drv, &local_err);
+ } else {
+ error_setg(errp, "Must specify either driver or file");
+ ret = -EINVAL;
+ goto unlink_and_fail;
+ }
}
if (!drv) {
@@ -1156,7 +1354,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
goto unlink_and_fail;
}
- if (bs->file != file) {
+ if (file && (bs->file != file)) {
bdrv_unref(file);
file = NULL;
}
@@ -1427,6 +1625,8 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state)
reopen_state->bs->enable_write_cache = !!(reopen_state->flags &
BDRV_O_CACHE_WB);
reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
+
+ bdrv_refresh_limits(reopen_state->bs);
}
/*
@@ -1501,7 +1701,7 @@ void bdrv_close_all(void)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
bdrv_close(bs);
}
}
@@ -1530,7 +1730,7 @@ static bool bdrv_requests_pending(BlockDriverState *bs)
static bool bdrv_requests_pending_all(void)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
if (bdrv_requests_pending(bs)) {
return true;
}
@@ -1557,7 +1757,7 @@ void bdrv_drain_all(void)
BlockDriverState *bs;
while (busy) {
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
bdrv_start_throttled_reqs(bs);
}
@@ -1566,14 +1766,19 @@ void bdrv_drain_all(void)
}
}
-/* make a BlockDriverState anonymous by removing from bdrv_state list.
+/* make a BlockDriverState anonymous by removing from bdrv_state and
+ * graph_bdrv_state list.
Also, NULL terminate the device_name to prevent double remove */
void bdrv_make_anon(BlockDriverState *bs)
{
if (bs->device_name[0] != '\0') {
- QTAILQ_REMOVE(&bdrv_states, bs, list);
+ QTAILQ_REMOVE(&bdrv_states, bs, device_list);
}
bs->device_name[0] = '\0';
+ if (bs->node_name[0] != '\0') {
+ QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
+ }
+ bs->node_name[0] = '\0';
}
static void bdrv_rebind(BlockDriverState *bs)
@@ -1593,7 +1798,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
bs_dest->dev_ops = bs_src->dev_ops;
bs_dest->dev_opaque = bs_src->dev_opaque;
bs_dest->dev = bs_src->dev;
- bs_dest->buffer_alignment = bs_src->buffer_alignment;
+ bs_dest->guest_block_size = bs_src->guest_block_size;
bs_dest->copy_on_read = bs_src->copy_on_read;
bs_dest->enable_write_cache = bs_src->enable_write_cache;
@@ -1627,7 +1832,12 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
/* keep the same entry in bdrv_states */
pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name),
bs_src->device_name);
- bs_dest->list = bs_src->list;
+ bs_dest->device_list = bs_src->device_list;
+
+ /* keep the same entry in graph_bdrv_states
+ * We do want to swap name but don't want to swap linked list entries
+ */
+ bs_dest->node_list = bs_src->node_list;
}
/*
@@ -1745,7 +1955,7 @@ void bdrv_detach_dev(BlockDriverState *bs, void *dev)
bs->dev = NULL;
bs->dev_ops = NULL;
bs->dev_opaque = NULL;
- bs->buffer_alignment = 512;
+ bs->guest_block_size = 512;
}
/* TODO change to return DeviceState * when all users are qdevified */
@@ -1876,10 +2086,10 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
int bdrv_commit(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
- int64_t sector, total_sectors;
+ int64_t sector, total_sectors, length, backing_length;
int n, ro, open_flags;
int ret = 0;
- uint8_t *buf;
+ uint8_t *buf = NULL;
char filename[PATH_MAX];
if (!drv)
@@ -1904,7 +2114,29 @@ int bdrv_commit(BlockDriverState *bs)
}
}
- total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
+ length = bdrv_getlength(bs);
+ if (length < 0) {
+ ret = length;
+ goto ro_cleanup;
+ }
+
+ backing_length = bdrv_getlength(bs->backing_hd);
+ if (backing_length < 0) {
+ ret = backing_length;
+ goto ro_cleanup;
+ }
+
+ /* If our top snapshot is larger than the backing file image,
+ * grow the backing file image if possible. If not possible,
+ * we must return an error */
+ if (length > backing_length) {
+ ret = bdrv_truncate(bs->backing_hd, length);
+ if (ret < 0) {
+ goto ro_cleanup;
+ }
+ }
+
+ total_sectors = length >> BDRV_SECTOR_BITS;
buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
for (sector = 0; sector < total_sectors; sector += n) {
@@ -1913,13 +2145,13 @@ int bdrv_commit(BlockDriverState *bs)
goto ro_cleanup;
}
if (ret) {
- if (bdrv_read(bs, sector, buf, n) != 0) {
- ret = -EIO;
+ ret = bdrv_read(bs, sector, buf, n);
+ if (ret < 0) {
goto ro_cleanup;
}
- if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
- ret = -EIO;
+ ret = bdrv_write(bs->backing_hd, sector, buf, n);
+ if (ret < 0) {
goto ro_cleanup;
}
}
@@ -1927,6 +2159,9 @@ int bdrv_commit(BlockDriverState *bs)
if (drv->bdrv_make_empty) {
ret = drv->bdrv_make_empty(bs);
+ if (ret < 0) {
+ goto ro_cleanup;
+ }
bdrv_flush(bs);
}
@@ -1934,9 +2169,11 @@ int bdrv_commit(BlockDriverState *bs)
* Make sure all data we wrote to the backing device is actually
* stable on disk.
*/
- if (bs->backing_hd)
+ if (bs->backing_hd) {
bdrv_flush(bs->backing_hd);
+ }
+ ret = 0;
ro_cleanup:
g_free(buf);
@@ -1952,7 +2189,7 @@ int bdrv_commit_all(void)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
if (bs->drv && bs->backing_hd) {
int ret = bdrv_commit(bs);
if (ret < 0) {
@@ -1970,6 +2207,10 @@ int bdrv_commit_all(void)
*/
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);
}
@@ -1979,15 +2220,18 @@ static void tracked_request_end(BdrvTrackedRequest *req)
*/
static void tracked_request_begin(BdrvTrackedRequest *req,
BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, bool is_write)
+ int64_t offset,
+ unsigned int bytes, bool is_write)
{
*req = (BdrvTrackedRequest){
.bs = bs,
- .sector_num = sector_num,
- .nb_sectors = nb_sectors,
- .is_write = is_write,
- .co = qemu_coroutine_self(),
+ .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);
@@ -1995,6 +2239,21 @@ static void tracked_request_begin(BdrvTrackedRequest *req,
QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
}
+static void mark_request_serialising(BdrvTrackedRequest *req, size_t align)
+{
+ int64_t overlap_offset = req->offset & ~(align - 1);
+ 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
*/
@@ -2016,53 +2275,75 @@ void bdrv_round_to_clusters(BlockDriverState *bs,
}
}
+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 sector_num, int nb_sectors) {
+ int64_t offset, unsigned int bytes)
+{
/* aaaa bbbb */
- if (sector_num >= req->sector_num + req->nb_sectors) {
+ if (offset >= req->overlap_offset + req->overlap_bytes) {
return false;
}
/* bbbb aaaa */
- if (req->sector_num >= sector_num + nb_sectors) {
+ if (req->overlap_offset >= offset + bytes) {
return false;
}
return true;
}
-static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors)
+static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
{
+ BlockDriverState *bs = self->bs;
BdrvTrackedRequest *req;
- int64_t cluster_sector_num;
- int cluster_nb_sectors;
bool retry;
+ bool waited = false;
- /* 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.
- */
- bdrv_round_to_clusters(bs, sector_num, nb_sectors,
- &cluster_sector_num, &cluster_nb_sectors);
+ if (!bs->serialising_in_flight) {
+ return false;
+ }
do {
retry = false;
QLIST_FOREACH(req, &bs->tracked_requests, list) {
- if (tracked_request_overlaps(req, cluster_sector_num,
- cluster_nb_sectors)) {
+ 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);
- qemu_co_queue_wait(&req->wait_queue);
- retry = true;
- break;
+ /* 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;
}
/*
@@ -2224,6 +2505,7 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
}
new_top_bs->backing_hd = base_bs;
+ bdrv_refresh_limits(new_top_bs);
QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
/* so that bdrv_close() does not recursively close the chain */
@@ -2271,8 +2553,7 @@ static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
typedef struct RwCo {
BlockDriverState *bs;
- int64_t sector_num;
- int nb_sectors;
+ int64_t offset;
QEMUIOVector *qiov;
bool is_write;
int ret;
@@ -2284,34 +2565,32 @@ static void coroutine_fn bdrv_rw_co_entry(void *opaque)
RwCo *rwco = opaque;
if (!rwco->is_write) {
- rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num,
- rwco->nb_sectors, rwco->qiov,
- rwco->flags);
- } else {
- rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num,
- rwco->nb_sectors, rwco->qiov,
+ 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_rwv_co(BlockDriverState *bs, int64_t sector_num,
- QEMUIOVector *qiov, bool is_write,
- BdrvRequestFlags flags)
+static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
+ QEMUIOVector *qiov, bool is_write,
+ BdrvRequestFlags flags)
{
Coroutine *co;
RwCo rwco = {
.bs = bs,
- .sector_num = sector_num,
- .nb_sectors = qiov->size >> BDRV_SECTOR_BITS,
+ .offset = offset,
.qiov = qiov,
.is_write = is_write,
.ret = NOT_DONE,
.flags = flags,
};
- assert((qiov->size & (BDRV_SECTOR_SIZE - 1)) == 0);
/**
* In sync call context, when the vcpu is blocked, this throttling timer
@@ -2350,7 +2629,8 @@ static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
};
qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_rwv_co(bs, sector_num, &qiov, is_write, flags);
+ 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 */
@@ -2386,11 +2666,6 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num,
return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
}
-int bdrv_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov)
-{
- return bdrv_rwv_co(bs, sector_num, qiov, true, 0);
-}
-
int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, BdrvRequestFlags flags)
{
@@ -2440,117 +2715,53 @@ int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
}
}
-int bdrv_pread(BlockDriverState *bs, int64_t offset,
- void *buf, int count1)
+int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
{
- uint8_t tmp_buf[BDRV_SECTOR_SIZE];
- int len, nb_sectors, count;
- int64_t sector_num;
+ QEMUIOVector qiov;
+ struct iovec iov = {
+ .iov_base = (void *)buf,
+ .iov_len = bytes,
+ };
int ret;
- count = count1;
- /* first read to align to sector start */
- len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
- if (len > count)
- len = count;
- sector_num = offset >> BDRV_SECTOR_BITS;
- if (len > 0) {
- if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
- return ret;
- memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
- count -= len;
- if (count == 0)
- return count1;
- sector_num++;
- buf += len;
- }
-
- /* read the sectors "in place" */
- nb_sectors = count >> BDRV_SECTOR_BITS;
- if (nb_sectors > 0) {
- if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
- return ret;
- sector_num += nb_sectors;
- len = nb_sectors << BDRV_SECTOR_BITS;
- buf += len;
- count -= len;
+ if (bytes < 0) {
+ return -EINVAL;
}
- /* add data from the last sector */
- if (count > 0) {
- if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
- return ret;
- memcpy(buf, tmp_buf, count);
+ qemu_iovec_init_external(&qiov, &iov, 1);
+ ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
+ if (ret < 0) {
+ return ret;
}
- return count1;
+
+ return bytes;
}
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
{
- uint8_t tmp_buf[BDRV_SECTOR_SIZE];
- int len, nb_sectors, count;
- int64_t sector_num;
int ret;
- count = qiov->size;
-
- /* first write to align to sector start */
- len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
- if (len > count)
- len = count;
- sector_num = offset >> BDRV_SECTOR_BITS;
- if (len > 0) {
- if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
- return ret;
- qemu_iovec_to_buf(qiov, 0, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)),
- len);
- if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
- return ret;
- count -= len;
- if (count == 0)
- return qiov->size;
- sector_num++;
- }
-
- /* write the sectors "in place" */
- nb_sectors = count >> BDRV_SECTOR_BITS;
- if (nb_sectors > 0) {
- QEMUIOVector qiov_inplace;
-
- qemu_iovec_init(&qiov_inplace, qiov->niov);
- qemu_iovec_concat(&qiov_inplace, qiov, len,
- nb_sectors << BDRV_SECTOR_BITS);
- ret = bdrv_writev(bs, sector_num, &qiov_inplace);
- qemu_iovec_destroy(&qiov_inplace);
- if (ret < 0) {
- return ret;
- }
-
- sector_num += nb_sectors;
- len = nb_sectors << BDRV_SECTOR_BITS;
- count -= len;
+ ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
+ if (ret < 0) {
+ return ret;
}
- /* add data from the last sector */
- if (count > 0) {
- if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
- return ret;
- qemu_iovec_to_buf(qiov, qiov->size - count, tmp_buf, count);
- if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
- return ret;
- }
return qiov->size;
}
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
- const void *buf, int count1)
+ const void *buf, int bytes)
{
QEMUIOVector qiov;
struct iovec iov = {
.iov_base = (void *) buf,
- .iov_len = count1,
+ .iov_len = bytes,
};
+ if (bytes < 0) {
+ return -EINVAL;
+ }
+
qemu_iovec_init_external(&qiov, &iov, 1);
return bdrv_pwritev(bs, offset, &qiov);
}
@@ -2646,40 +2857,34 @@ err:
}
/*
- * Handle a read request in coroutine context
+ * 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_co_do_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
+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;
- BdrvTrackedRequest req;
int ret;
- if (!drv) {
- return -ENOMEDIUM;
- }
- if (bdrv_check_request(bs, sector_num, nb_sectors)) {
- return -EIO;
- }
+ int64_t sector_num = offset >> BDRV_SECTOR_BITS;
+ unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
- if (bs->copy_on_read) {
- flags |= BDRV_REQ_COPY_ON_READ;
- }
- if (flags & BDRV_REQ_COPY_ON_READ) {
- bs->copy_on_read_in_flight++;
- }
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- if (bs->copy_on_read_in_flight) {
- wait_for_overlapping_requests(bs, sector_num, nb_sectors);
- }
-
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, nb_sectors, false);
+ /* 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));
}
- tracked_request_begin(&req, bs, sector_num, nb_sectors, false);
+ wait_serialising_requests(req);
if (flags & BDRV_REQ_COPY_ON_READ) {
int pnum;
@@ -2695,6 +2900,7 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
}
}
+ /* Forward the request to the BlockDriver */
if (!(bs->zero_beyond_eof && bs->growable)) {
ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
} else {
@@ -2708,7 +2914,8 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
}
total_sectors = DIV_ROUND_UP(len, BDRV_SECTOR_SIZE);
- max_nb_sectors = MAX(0, total_sectors - sector_num);
+ max_nb_sectors = MAX(0, ROUND_UP(total_sectors - sector_num,
+ align >> BDRV_SECTOR_BITS));
if (max_nb_sectors > 0) {
ret = drv->bdrv_co_readv(bs, sector_num,
MIN(nb_sectors, max_nb_sectors), qiov);
@@ -2726,15 +2933,95 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
}
out:
+ return ret;
+}
+
+/*
+ * 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;
+
+ /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
+ uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+ uint8_t *head_buf = NULL;
+ uint8_t *tail_buf = NULL;
+ QEMUIOVector local_qiov;
+ bool use_local_qiov = false;
+ int ret;
+
+ if (!drv) {
+ return -ENOMEDIUM;
+ }
+ if (bdrv_check_byte_request(bs, offset, bytes)) {
+ return -EIO;
+ }
+
+ 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 (flags & BDRV_REQ_COPY_ON_READ) {
- bs->copy_on_read_in_flight--;
+ 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 > (UINT_MAX >> BDRV_SECTOR_BITS)) {
+ 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)
{
@@ -2828,46 +3115,37 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
}
/*
- * Handle a write request in coroutine context
+ * Forwards an already correctly aligned write request to the BlockDriver.
*/
-static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
+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;
- BdrvTrackedRequest req;
+ bool waited;
int ret;
- if (!bs->drv) {
- return -ENOMEDIUM;
- }
- if (bs->read_only) {
- return -EACCES;
- }
- if (bdrv_check_request(bs, sector_num, nb_sectors)) {
- return -EIO;
- }
+ int64_t sector_num = offset >> BDRV_SECTOR_BITS;
+ unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
- if (bs->copy_on_read_in_flight) {
- wait_for_overlapping_requests(bs, sector_num, nb_sectors);
- }
-
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, nb_sectors, true);
- }
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
+ waited = wait_serialising_requests(req);
+ assert(!waited || !req->serialising);
- ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req);
+ ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
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);
@@ -2882,11 +3160,143 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
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;
+ /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
+ uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+ 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;
+ }
+ if (bdrv_check_byte_request(bs, offset, bytes)) {
+ return -EIO;
+ }
+
+ /* 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);
+ }
+
+ 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 > (INT_MAX >> BDRV_SECTOR_BITS)) {
+ 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)
{
@@ -3110,11 +3520,12 @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
}
}
+/* This function is to find block backend bs */
BlockDriverState *bdrv_find(const char *name)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
if (!strcmp(name, bs->device_name)) {
return bs;
}
@@ -3122,19 +3533,83 @@ BlockDriverState *bdrv_find(const char *name)
return NULL;
}
+/* This function is to find a node in the bs graph */
+BlockDriverState *bdrv_find_node(const char *node_name)
+{
+ BlockDriverState *bs;
+
+ assert(node_name);
+
+ QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
+ if (!strcmp(node_name, bs->node_name)) {
+ return bs;
+ }
+ }
+ return NULL;
+}
+
+/* Put this QMP function here so it can access the static graph_bdrv_states. */
+BlockDeviceInfoList *bdrv_named_nodes_list(void)
+{
+ BlockDeviceInfoList *list, *entry;
+ BlockDriverState *bs;
+
+ list = NULL;
+ QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
+ entry = g_malloc0(sizeof(*entry));
+ entry->value = bdrv_block_device_info(bs);
+ entry->next = list;
+ list = entry;
+ }
+
+ return list;
+}
+
+BlockDriverState *bdrv_lookup_bs(const char *device,
+ const char *node_name,
+ Error **errp)
+{
+ BlockDriverState *bs = NULL;
+
+ if ((!device && !node_name) || (device && node_name)) {
+ error_setg(errp, "Use either device or node-name but not both");
+ return NULL;
+ }
+
+ if (device) {
+ bs = bdrv_find(device);
+
+ if (!bs) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+ return NULL;
+ }
+
+ return bs;
+ }
+
+ bs = bdrv_find_node(node_name);
+
+ if (!bs) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, node_name);
+ return NULL;
+ }
+
+ return bs;
+}
+
BlockDriverState *bdrv_next(BlockDriverState *bs)
{
if (!bs) {
return QTAILQ_FIRST(&bdrv_states);
}
- return QTAILQ_NEXT(bs, list);
+ return QTAILQ_NEXT(bs, device_list);
}
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
it(opaque, bs);
}
}
@@ -3154,7 +3629,7 @@ int bdrv_flush_all(void)
BlockDriverState *bs;
int result = 0;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
int ret = bdrv_flush(bs);
if (ret < 0 && !result) {
result = ret;
@@ -4278,7 +4753,7 @@ void bdrv_invalidate_cache_all(void)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
bdrv_invalidate_cache(bs);
}
}
@@ -4287,7 +4762,7 @@ void bdrv_clear_incoming_migration_all(void)
{
BlockDriverState *bs;
- QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING);
}
}
@@ -4314,9 +4789,15 @@ int bdrv_flush(BlockDriverState *bs)
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)
{
- RwCo *rwco = opaque;
+ DiscardCo *rwco = opaque;
rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
}
@@ -4400,7 +4881,7 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
{
Coroutine *co;
- RwCo rwco = {
+ DiscardCo rwco = {
.bs = bs,
.sector_num = sector_num,
.nb_sectors = nb_sectors,
@@ -4505,14 +4986,14 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
return NULL;
}
-void bdrv_set_buffer_alignment(BlockDriverState *bs, int align)
+void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
{
- bs->buffer_alignment = align;
+ bs->guest_block_size = align;
}
void *qemu_blockalign(BlockDriverState *bs, size_t size)
{
- return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
+ return qemu_memalign(bdrv_opt_mem_align(bs), size);
}
/*
@@ -4521,9 +5002,13 @@ void *qemu_blockalign(BlockDriverState *bs, size_t size)
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 % bs->buffer_alignment) {
+ if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
+ return false;
+ }
+ if (qiov->iov[i].iov_len % alignment) {
return false;
}
}
@@ -4875,21 +5360,68 @@ int bdrv_amend_options(BlockDriverState *bs, QEMUOptionParameter *options)
return bs->drv->bdrv_amend_options(bs, options);
}
-ExtSnapshotPerm bdrv_check_ext_snapshot(BlockDriverState *bs)
+/* Used to recurse on single child block filters.
+ * Single child block filter will store their child in bs->file.
+ */
+bool bdrv_generic_is_first_non_filter(BlockDriverState *bs,
+ BlockDriverState *candidate)
{
- if (bs->drv->bdrv_check_ext_snapshot) {
- return bs->drv->bdrv_check_ext_snapshot(bs);
+ if (!bs->drv) {
+ return false;
}
- if (bs->file && bs->file->drv && bs->file->drv->bdrv_check_ext_snapshot) {
- return bs->file->drv->bdrv_check_ext_snapshot(bs);
+ if (!bs->drv->authorizations[BS_IS_A_FILTER]) {
+ if (bs == candidate) {
+ return true;
+ } else {
+ return false;
+ }
+ }
+
+ if (!bs->drv->authorizations[BS_FILTER_PASS_DOWN]) {
+ return false;
+ }
+
+ if (!bs->file) {
+ return false;
}
- /* external snapshots are allowed by default */
- return EXT_SNAPSHOT_ALLOWED;
+ return bdrv_recurse_is_first_non_filter(bs->file, candidate);
}
-ExtSnapshotPerm bdrv_check_ext_snapshot_forbidden(BlockDriverState *bs)
+bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
+ BlockDriverState *candidate)
+{
+ if (bs->drv && bs->drv->bdrv_recurse_is_first_non_filter) {
+ return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
+ }
+
+ return bdrv_generic_is_first_non_filter(bs, candidate);
+}
+
+/* This function checks if the candidate is the first non filter bs down it's
+ * bs chain. Since we don't have pointers to parents it explore all bs chains
+ * from the top. Some filters can choose not to pass down the recursion.
+ */
+bool bdrv_is_first_non_filter(BlockDriverState *candidate)
{
- return EXT_SNAPSHOT_FORBIDDEN;
+ BlockDriverState *bs;
+
+ /* walk down the bs forest recursively */
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
+ bool perm;
+
+ if (!bs->file) {
+ continue;
+ }
+
+ perm = bdrv_recurse_is_first_non_filter(bs->file, candidate);
+
+ /* candidate is the first non filter */
+ if (perm) {
+ return true;
+ }
+ }
+
+ return false;
}
generated by cgit v1.2.1 (git 2.18.0) at 2024-06-20 10:00:13 +0000