Re: [PATCH] block/rbd: implement bdrv_co_block_status
Am 10.08.21 um 10:51 schrieb Stefano Garzarella:
On Mon, Aug 09, 2021 at 03:41:36PM +0200, Peter Lieven wrote:
Please, can you add a description?
For example also describing what happens if RBD image does not support
RBD_FEATURE_FAST_DIFF.
Sure.
Signed-off-by: Peter Lieven
---
block/rbd.c | 119
1 file changed, 119 insertions(+)
diff --git a/block/rbd.c b/block/rbd.c
index dcf82b15b8..ef1eaa6af3 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -88,6 +88,7 @@ typedef struct BDRVRBDState {
char *namespace;
uint64_t image_size;
uint64_t object_size;
+ uint64_t features;
} BDRVRBDState;
typedef struct RBDTask {
@@ -983,6 +984,14 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict
*options, int flags,
s->image_size = info.size;
s->object_size = info.obj_size;
+ r = rbd_get_features(s->image, >features);
+ if (r < 0) {
+ error_setg_errno(errp, -r, "error getting image features from %s",
+ s->image_name);
+ rbd_close(s->image);
+ goto failed_open;
^
You can use `failed_post_open` label here, so you can avoid to call rbd_close().
Bad me, I developed this patch in a Qemu version where failed_post_open wasn't
present...
+ }
+
/* If we are using an rbd snapshot, we must be r/o, otherwise
* leave as-is */
if (s->snap != NULL) {
@@ -1259,6 +1268,115 @@ static ImageInfoSpecific
*qemu_rbd_get_specific_info(BlockDriverState *bs,
return spec_info;
}
+typedef struct rbd_diff_req {
+ uint64_t offs;
+ uint64_t bytes;
+ int exists;
+} rbd_diff_req;
+
+static int qemu_rbd_co_block_status_cb(uint64_t offs, size_t len,
+ int exists, void *opaque)
+{
+ struct rbd_diff_req *req = opaque;
+
+ assert(req->offs + req->bytes <= offs);
+ assert(offs >= req->offs + req->bytes);
I think just one of the two asserts is enough, isn't that the same condition?
Right.
+
+ if (req->exists && offs > req->offs + req->bytes) {
+ /*
+ * we started in an allocated area and jumped over an unallocated area,
+ * req->bytes contains the length of the allocated area before the
+ * unallocated area. stop further processing.
+ */
+ return -9000;
^
What is this magical value?
Please add a macro (with a comment) and also use it below in other places.
Will add in V2.
+ }
+ if (req->exists && !exists) {
+ /*
+ * we started in an allocated area and reached a hole. req->bytes
+ * contains the length of the allocated area before the hole.
+ * stop further processing.
+ */
+ return -9000;
+ }
+ if (!req->exists && exists && offs > req->offs) {
+ /*
+ * we started in an unallocated area and hit the first allocated
+ * block. req->bytes must be set to the length of the unallocated area
+ * before the allocated area. stop further processing.
+ */
+ req->bytes = offs - req->offs;
+ return -9000;
+ }
+
+ /*
+ * assert that we catched all cases above and allocation state has not
+ * changed during callbacks.
+ */
+ assert(exists == req->exists || !req->bytes);
+ req->exists = exists;
+
+ /*
+ * assert that we either return an unallocated block or have got callbacks
+ * for all allocated blocks present.
+ */
+ assert(!req->exists || offs == req->offs + req->bytes);
+ req->bytes = offs + len - req->offs;
+
+ return 0;
+}
+
+static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t
offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
+{
+ BDRVRBDState *s = bs->opaque;
+ int ret, r;
+ struct rbd_diff_req req = { .offs = offset };
+
+ assert(offset + bytes <= s->image_size);
+
+ /* default to all sectors allocated */
+ ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+ if (map) {
+ *map = offset;
+ }
+ *pnum = bytes;
+
+ /* RBD image does not support fast-diff */
+ if (!(s->features & RBD_FEATURE_FAST_DIFF)) {
+ goto out;
+ }
+
+ r = rbd_diff_iterate2(s->image, NULL, offset, bytes, true, true,
+ qemu_rbd_co_block_status_cb, );
+ if (r < 0 && r != -9000) {
+ goto out;
+ }
+ assert(req.bytes <= bytes);
+ if (!req.exists) {
+ if (r == 0 && !req.bytes) {
+ /*
+ * rbd_diff_iterate2 does not invoke callbacks for unallocated
areas
+ * except for the case where an overlay has a hole where the parent
+ * has not. This here catches the case where no callback was
+ * invoked at all.
+ */
+ req.bytes = bytes;
+
Re: [PATCH] block/rbd: implement bdrv_co_block_status
On Mon, Aug 09, 2021 at 03:41:36PM +0200, Peter Lieven wrote:
Please, can you add a description?
For example also describing what happens if RBD image does not support
RBD_FEATURE_FAST_DIFF.
Signed-off-by: Peter Lieven
---
block/rbd.c | 119
1 file changed, 119 insertions(+)
diff --git a/block/rbd.c b/block/rbd.c
index dcf82b15b8..ef1eaa6af3 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -88,6 +88,7 @@ typedef struct BDRVRBDState {
char *namespace;
uint64_t image_size;
uint64_t object_size;
+uint64_t features;
} BDRVRBDState;
typedef struct RBDTask {
@@ -983,6 +984,14 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict
*options, int flags,
s->image_size = info.size;
s->object_size = info.obj_size;
+r = rbd_get_features(s->image, >features);
+if (r < 0) {
+error_setg_errno(errp, -r, "error getting image features from %s",
+ s->image_name);
+rbd_close(s->image);
+goto failed_open;
^
You can use `failed_post_open` label here, so you can avoid to call
rbd_close().
+}
+
/* If we are using an rbd snapshot, we must be r/o, otherwise
* leave as-is */
if (s->snap != NULL) {
@@ -1259,6 +1268,115 @@ static ImageInfoSpecific
*qemu_rbd_get_specific_info(BlockDriverState *bs,
return spec_info;
}
+typedef struct rbd_diff_req {
+uint64_t offs;
+uint64_t bytes;
+int exists;
+} rbd_diff_req;
+
+static int qemu_rbd_co_block_status_cb(uint64_t offs, size_t len,
+ int exists, void *opaque)
+{
+struct rbd_diff_req *req = opaque;
+
+assert(req->offs + req->bytes <= offs);
+assert(offs >= req->offs + req->bytes);
I think just one of the two asserts is enough, isn't that the same
condition?
+
+if (req->exists && offs > req->offs + req->bytes) {
+/*
+ * we started in an allocated area and jumped over an unallocated area,
+ * req->bytes contains the length of the allocated area before the
+ * unallocated area. stop further processing.
+ */
+return -9000;
^
What is this magical value?
Please add a macro (with a comment) and also use it below in other
places.
+}
+if (req->exists && !exists) {
+/*
+ * we started in an allocated area and reached a hole.
req->bytes
+ * contains the length of the allocated area before the hole.
+ * stop further processing.
+ */
+return -9000;
+}
+if (!req->exists && exists && offs > req->offs) {
+/*
+ * we started in an unallocated area and hit the first allocated
+ * block. req->bytes must be set to the length of the unallocated area
+ * before the allocated area. stop further processing.
+ */
+req->bytes = offs - req->offs;
+return -9000;
+}
+
+/*
+ * assert that we catched all cases above and allocation state has not
+ * changed during callbacks.
+ */
+assert(exists == req->exists || !req->bytes);
+req->exists = exists;
+
+/*
+ * assert that we either return an unallocated block or have got callbacks
+ * for all allocated blocks present.
+ */
+assert(!req->exists || offs == req->offs + req->bytes);
+req->bytes = offs + len - req->offs;
+
+return 0;
+}
+
+static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t
offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
+{
+BDRVRBDState *s = bs->opaque;
+int ret, r;
+struct rbd_diff_req req = { .offs = offset };
+
+assert(offset + bytes <= s->image_size);
+
+/* default to all sectors allocated */
+ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+if (map) {
+*map = offset;
+}
+*pnum = bytes;
+
+/* RBD image does not support fast-diff */
+if (!(s->features & RBD_FEATURE_FAST_DIFF)) {
+goto out;
+}
+
+r = rbd_diff_iterate2(s->image, NULL, offset, bytes, true, true,
+ qemu_rbd_co_block_status_cb, );
+if (r < 0 && r != -9000) {
+goto out;
+}
+assert(req.bytes <= bytes);
+if (!req.exists) {
+if (r == 0 && !req.bytes) {
+/*
+ * rbd_diff_iterate2 does not invoke callbacks for
unallocated areas
+ * except for the case where an overlay has a hole where
the parent
+ * has not. This here catches the case where no callback
was
+ * invoked at all.
+ */
+req.bytes = bytes;
+}
+ret &= ~BDRV_BLOCK_DATA;
+ret |= BDRV_BLOCK_ZERO;
+}
+*pnum = req.bytes;
+
+out:
+if (ret > 0 &&
[PATCH] block/rbd: implement bdrv_co_block_status
Signed-off-by: Peter Lieven
---
block/rbd.c | 119
1 file changed, 119 insertions(+)
diff --git a/block/rbd.c b/block/rbd.c
index dcf82b15b8..ef1eaa6af3 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -88,6 +88,7 @@ typedef struct BDRVRBDState {
char *namespace;
uint64_t image_size;
uint64_t object_size;
+uint64_t features;
} BDRVRBDState;
typedef struct RBDTask {
@@ -983,6 +984,14 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict
*options, int flags,
s->image_size = info.size;
s->object_size = info.obj_size;
+r = rbd_get_features(s->image, >features);
+if (r < 0) {
+error_setg_errno(errp, -r, "error getting image features from %s",
+ s->image_name);
+rbd_close(s->image);
+goto failed_open;
+}
+
/* If we are using an rbd snapshot, we must be r/o, otherwise
* leave as-is */
if (s->snap != NULL) {
@@ -1259,6 +1268,115 @@ static ImageInfoSpecific
*qemu_rbd_get_specific_info(BlockDriverState *bs,
return spec_info;
}
+typedef struct rbd_diff_req {
+uint64_t offs;
+uint64_t bytes;
+int exists;
+} rbd_diff_req;
+
+static int qemu_rbd_co_block_status_cb(uint64_t offs, size_t len,
+ int exists, void *opaque)
+{
+struct rbd_diff_req *req = opaque;
+
+assert(req->offs + req->bytes <= offs);
+assert(offs >= req->offs + req->bytes);
+
+if (req->exists && offs > req->offs + req->bytes) {
+/*
+ * we started in an allocated area and jumped over an unallocated area,
+ * req->bytes contains the length of the allocated area before the
+ * unallocated area. stop further processing.
+ */
+return -9000;
+}
+if (req->exists && !exists) {
+/*
+ * we started in an allocated area and reached a hole. req->bytes
+ * contains the length of the allocated area before the hole.
+ * stop further processing.
+ */
+return -9000;
+}
+if (!req->exists && exists && offs > req->offs) {
+/*
+ * we started in an unallocated area and hit the first allocated
+ * block. req->bytes must be set to the length of the unallocated area
+ * before the allocated area. stop further processing.
+ */
+req->bytes = offs - req->offs;
+return -9000;
+}
+
+/*
+ * assert that we catched all cases above and allocation state has not
+ * changed during callbacks.
+ */
+assert(exists == req->exists || !req->bytes);
+req->exists = exists;
+
+/*
+ * assert that we either return an unallocated block or have got callbacks
+ * for all allocated blocks present.
+ */
+assert(!req->exists || offs == req->offs + req->bytes);
+req->bytes = offs + len - req->offs;
+
+return 0;
+}
+
+static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t
offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
+{
+BDRVRBDState *s = bs->opaque;
+int ret, r;
+struct rbd_diff_req req = { .offs = offset };
+
+assert(offset + bytes <= s->image_size);
+
+/* default to all sectors allocated */
+ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+if (map) {
+*map = offset;
+}
+*pnum = bytes;
+
+/* RBD image does not support fast-diff */
+if (!(s->features & RBD_FEATURE_FAST_DIFF)) {
+goto out;
+}
+
+r = rbd_diff_iterate2(s->image, NULL, offset, bytes, true, true,
+ qemu_rbd_co_block_status_cb, );
+if (r < 0 && r != -9000) {
+goto out;
+}
+assert(req.bytes <= bytes);
+if (!req.exists) {
+if (r == 0 && !req.bytes) {
+/*
+ * rbd_diff_iterate2 does not invoke callbacks for unallocated
areas
+ * except for the case where an overlay has a hole where the parent
+ * has not. This here catches the case where no callback was
+ * invoked at all.
+ */
+req.bytes = bytes;
+}
+ret &= ~BDRV_BLOCK_DATA;
+ret |= BDRV_BLOCK_ZERO;
+}
+*pnum = req.bytes;
+
+out:
+if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID && file) {
+*file = bs;
+}
+return ret;
+}
+
static int64_t qemu_rbd_getlength(BlockDriverState *bs)
{
BDRVRBDState *s = bs->opaque;
@@ -1494,6 +1612,7 @@ static BlockDriver bdrv_rbd = {
#ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
.bdrv_co_pwrite_zeroes = qemu_rbd_co_pwrite_zeroes,
#endif
+.bdrv_co_block_status = qemu_rbd_co_block_status,
.bdrv_snapshot_create = qemu_rbd_snap_create,
.bdrv_snapshot_delete =
