'detect-zeroes' is one of the basic BlockdevOptions available for all
drivers, but it's silently ignored by bdrv_reopen_prepare/commit(), so
the user cannot change it and doesn't get an error explaining that it
can't be changed.
This should update the detect-zeroes setting, but does nothing:
(qemu) qemu-io virtio0 "reopen -o detect-zeroes=on"
This should return an error but also does nothing:
(qemu) qemu-io virtio0 "reopen -o discard=off,detect-zeroes=unmap"
Since there's no reason why we shouldn't allow changing it and the
implementation is simple let's just do it.
Signed-off-by: Alberto Garcia <be...@igalia.com>
---
block.c | 63 +++++++++++++++++++++++++++++++--------------------
include/block/block.h | 1 +
2 files changed, 40 insertions(+), 24 deletions(-)
diff --git a/block.c b/block.c
index 21f1eb9cd1..9aed5c19f4 100644
--- a/block.c
+++ b/block.c
@@ -764,6 +764,30 @@ static void bdrv_join_options(BlockDriverState *bs, QDict
*options,
}
}
+static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,
+ int open_flags,
+ Error **errp)
+{
+ Error *local_err = NULL;
+ const char *value = qemu_opt_get(opts, "detect-zeroes");
+ BlockdevDetectZeroesOptions detect_zeroes =
+ qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value,
+ BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return detect_zeroes;
+ }
+
+ if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
+ !(open_flags & BDRV_O_UNMAP))
+ {
+ error_setg(errp, "setting detect-zeroes to unmap is not allowed "
+ "without setting discard operation to unmap");
+ }
+
+ return detect_zeroes;
+}
+
/**
* Set open flags for a given discard mode
*
@@ -1328,7 +1352,6 @@ static int bdrv_open_common(BlockDriverState *bs,
BlockBackend *file,
const char *driver_name = NULL;
const char *node_name = NULL;
const char *discard;
- const char *detect_zeroes;
QemuOpts *opts;
BlockDriver *drv;
Error *local_err = NULL;
@@ -1417,29 +1440,12 @@ static int bdrv_open_common(BlockDriverState *bs,
BlockBackend *file,
}
}
- detect_zeroes = qemu_opt_get(opts, "detect-zeroes");
- if (detect_zeroes) {
- BlockdevDetectZeroesOptions value =
- qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
- detect_zeroes,
- BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
- &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- ret = -EINVAL;
- goto fail_opts;
- }
-
- if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
- !(bs->open_flags & BDRV_O_UNMAP))
- {
- error_setg(errp, "setting detect-zeroes to unmap is not allowed "
- "without setting discard operation to unmap");
- ret = -EINVAL;
- goto fail_opts;
- }
-
- bs->detect_zeroes = value;
+ bs->detect_zeroes =
+ bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto fail_opts;
}
if (filename != NULL) {
@@ -3187,6 +3193,14 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue,
}
}
+ reopen_state->detect_zeroes =
+ bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto error;
+ }
+
/* node-name and driver must be unchanged. Put them back into the QDict, so
* that they are checked at the end of this function. */
value = qemu_opt_get(opts, "node-name");
@@ -3344,6 +3358,7 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state)
bs->options = reopen_state->options;
bs->open_flags = reopen_state->flags;
bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
+ bs->detect_zeroes = reopen_state->detect_zeroes;
/* Remove child references from bs->options and bs->explicit_options */
QLIST_FOREACH(child, &bs->children, next) {
diff --git a/include/block/block.h b/include/block/block.h
index 4e0871aaf9..f71fa5a1c4 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -184,6 +184,7 @@ typedef QSIMPLEQ_HEAD(BlockReopenQueue,
BlockReopenQueueEntry) BlockReopenQueue;
typedef struct BDRVReopenState {
BlockDriverState *bs;
int flags;
+ BlockdevDetectZeroesOptions detect_zeroes;
uint64_t perm, shared_perm;
QDict *options;
QDict *explicit_options;
--
2.11.0
