[libvirt] [PATCH 1/2] resize: add virStorageVolResize() API
Osier Yang
jyang at redhat.com
Wed Jun 6 12:12:49 UTC 2012
On 2012年01月28日 08:28, Eric Blake wrote:
> From: "Zeeshan Ali (Khattak)"<zeeshanak at gnome.org>
>
> Add a new function to allow changing of capacity of storage volumes.
> Plan out several flags, even if not all of them will be implemented
> up front.
>
> Expose the new command via 'virsh vol-resize'.
>
> Signed-off-by: Eric Blake<eblake at redhat.com>
> ---
> include/libvirt/libvirt.h.in | 11 ++++++
> python/generator.py | 1 +
> src/driver.h | 5 +++
> src/libvirt.c | 76 ++++++++++++++++++++++++++++++++++++++
> src/libvirt_public.syms | 1 +
> tools/virsh.c | 82 ++++++++++++++++++++++++++++++++++++++++++
> tools/virsh.pod | 11 ++++++
> 7 files changed, 187 insertions(+), 0 deletions(-)
>
> diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
> index e99cd00..d26cbbd 100644
> --- a/include/libvirt/libvirt.h.in
> +++ b/include/libvirt/libvirt.h.in
> @@ -2386,6 +2386,17 @@ char * virStorageVolGetXMLDesc (virStorageVolPtr pool,
>
> char * virStorageVolGetPath (virStorageVolPtr vol);
>
> +typedef enum {
> + VIR_STORAGE_VOL_RESIZE_ALLOCATE = 1<< 0, /* force allocation of new size */
> + VIR_STORAGE_VOL_RESIZE_DELTA = 1<< 1, /* size is relative to current */
> + VIR_STORAGE_VOL_RESIZE_SHRINK = 1<< 2, /* allow decrease in capacity */
> +} virStorageVolResizeFlags;
> +
> +int virStorageVolResize (virStorageVolPtr vol,
> + long long capacity,
> + unsigned int flags);
> +
> +
> /**
> * virKeycodeSet:
> *
> diff --git a/python/generator.py b/python/generator.py
> index de635dc..791b267 100755
> --- a/python/generator.py
> +++ b/python/generator.py
> @@ -259,6 +259,7 @@ py_types = {
> 'double': ('d', None, "double", "double"),
> 'unsigned int': ('i', None, "int", "int"),
> 'unsigned long': ('l', None, "long", "long"),
> + 'long long': ('l', None, "longlong", "long long"),
> 'unsigned long long': ('l', None, "longlong", "long long"),
> 'unsigned char *': ('z', None, "charPtr", "char *"),
> 'char *': ('z', None, "charPtr", "char *"),
> diff --git a/src/driver.h b/src/driver.h
> index df2aa60..485b578 100644
> --- a/src/driver.h
> +++ b/src/driver.h
> @@ -1261,6 +1261,10 @@ typedef int
> unsigned long long offset,
> unsigned long long length,
> unsigned int flags);
> +typedef int
> + (*virDrvStorageVolResize) (virStorageVolPtr vol,
> + long long capacity,
> + unsigned int flags);
>
> typedef int
> (*virDrvStoragePoolIsActive)(virStoragePoolPtr pool);
> @@ -1323,6 +1327,7 @@ struct _virStorageDriver {
> virDrvStorageVolGetInfo volGetInfo;
> virDrvStorageVolGetXMLDesc volGetXMLDesc;
> virDrvStorageVolGetPath volGetPath;
> + virDrvStorageVolResize volResize;
> virDrvStoragePoolIsActive poolIsActive;
> virDrvStoragePoolIsPersistent poolIsPersistent;
> };
> diff --git a/src/libvirt.c b/src/libvirt.c
> index e9d638b..540d74a 100644
> --- a/src/libvirt.c
> +++ b/src/libvirt.c
> @@ -12927,6 +12927,82 @@ error:
> return NULL;
> }
>
> +/**
> + * virStorageVolResize:
> + * @vol: pointer to storage volume
> + * @capacity: new capacity, in bytes
> + * @flags: bitwise-OR of virStorageVolResizeFlags
> + *
> + * Changes the capacity of the storage volume @vol to @capacity. The
> + * operation will fail if the new capacity requires allocation that would
> + * exceed the remaining free space in the parent pool. The contents of
> + * the new capacity will appear as all zero bytes.
> + *
> + * Normally, the operation will attempt to affect capacity with a minimum
> + * impact on allocation (that is, the default operation favors a sparse
> + * resize). If @flags contains VIR_STORAGE_VOL_RESIZE_ALLOCATE, then the
> + * operation will ensure that allocation is sufficient for the new
> + * capacity; this may make the operation take noticeably longer.
> + *
> + * Normally, the operation treats @capacity as the new size in bytes;
> + * but if @flags contains VIR_STORAGE_RESIZE_DELTA, then @capacity
> + * represents the size difference to add to the current size. It is
> + * up to the storage pool implementation whether unaligned requests are
> + * rounded up to the next valid boundary, or rejected.
> + *
> + * Normally, this operation should only be used to enlarge capacity;
> + * but if @flags contains VIR_STORAGE_RESIZE_SHRINK, it is possible to
> + * attempt a reduction in capacity even though it might cause data loss.
> + *
> + * Returns 0 on success, or -1 on error.
> + */
> +int
> +virStorageVolResize(virStorageVolPtr vol,
> + long long capacity,
> + unsigned int flags)
> +{
> + virConnectPtr conn;
> + VIR_DEBUG("vol=%p capacity=%lld flags=%x", vol, capacity, flags);
> +
> + virResetLastError();
> +
> + if (!VIR_IS_STORAGE_VOL(vol)) {
> + virLibStorageVolError(VIR_ERR_INVALID_STORAGE_VOL, __FUNCTION__);
> + virDispatchError(NULL);
> + return -1;
> + }
> +
> + conn = vol->conn;
> +
> + if (conn->flags& VIR_CONNECT_RO) {
> + virLibConnError(VIR_ERR_OPERATION_DENIED, __FUNCTION__);
> + goto error;
> + }
> +
> + /* Negative capacity is valid only with both delta and shrink;
> + * zero capacity is valid with either delta or shrink. */
> + if ((capacity< 0&& !(flags& VIR_STORAGE_VOL_RESIZE_DELTA)&&
> + !(flags& VIR_STORAGE_VOL_RESIZE_SHRINK)) ||
> + (capacity == 0&& !((flags& VIR_STORAGE_VOL_RESIZE_DELTA) ||
> + (flags& VIR_STORAGE_VOL_RESIZE_SHRINK)))) {
> + virLibStorageVolError(VIR_ERR_INVALID_ARG, __FUNCTION__);
> + goto error;
> + }
> +
> + if (conn->storageDriver&& conn->storageDriver->volResize) {
> + int ret;
> + ret = conn->storageDriver->volResize(vol, capacity, flags);
> + if (ret< 0)
> + goto error;
> + return ret;
> + }
> +
> + virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
> +
> +error:
> + virDispatchError(vol->conn);
> + return -1;
> +}
>
> /**
> * virNodeNumOfDevices:
> diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
> index 1340b0c..8bdb24b 100644
> --- a/src/libvirt_public.syms
> +++ b/src/libvirt_public.syms
> @@ -519,6 +519,7 @@ LIBVIRT_0.9.9 {
> LIBVIRT_0.9.10 {
> global:
> virDomainShutdownFlags;
> + virStorageVolResize;
> virStorageVolWipePattern;
> } LIBVIRT_0.9.9;
>
> diff --git a/tools/virsh.c b/tools/virsh.c
> index 9b37dc0..ffcd746 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -11279,6 +11279,87 @@ cmdVolInfo(vshControl *ctl, const vshCmd *cmd)
> return ret;
> }
>
> +/*
> + * "vol-resize" command
> + */
> +static const vshCmdInfo info_vol_resize[] = {
> + {"help", N_("resize a vol")},
> + {"desc", N_("Resizes a storage volume.")},
> + {NULL, NULL}
> +};
> +
> +static const vshCmdOptDef opts_vol_resize[] = {
> + {"vol", VSH_OT_DATA, VSH_OFLAG_REQ, N_("vol name, key or path")},
> + {"capacity", VSH_OT_DATA, VSH_OFLAG_REQ,
> + N_("new capacity for the vol with optional k,M,G,T suffix")},
> + {"pool", VSH_OT_STRING, 0, N_("pool name or uuid")},
> + {"allocate", VSH_OT_BOOL, 0,
> + N_("allocate the new capacity, rather than leaving it sparse")},
> + {"delta", VSH_OT_BOOL, 0,
> + N_("use capacity as a delta to current size, rather than the new size")},
> + {"shrink", VSH_OT_BOOL, 0, N_("allow the resize to shrink the volume")},
> + {NULL, 0, 0, NULL}
> +};
> +
> +static bool
> +cmdVolResize(vshControl *ctl, const vshCmd *cmd)
> +{
> + virStorageVolPtr vol;
> + const char *capacityStr = NULL;
> + unsigned long long capacity = 0;
> + unsigned int flags = 0;
> + bool ret = false;
> + bool delta = false;
> +
> + if (vshCommandOptBool(cmd, "allocate"))
> + flags |= VIR_STORAGE_VOL_RESIZE_ALLOCATE;
> + if (vshCommandOptBool(cmd, "delta")) {
> + delta = true;
> + flags |= VIR_STORAGE_VOL_RESIZE_DELTA;
> + }
> + if (vshCommandOptBool(cmd, "shrink"))
> + flags |= VIR_STORAGE_VOL_RESIZE_SHRINK;
> +
> + if (!vshConnectionUsability(ctl, ctl->conn))
> + return false;
Late response, but it seems not good idea to expose the options
which are actually not implemented underlying yet. One would get
error like:
# virsh vol-resize /var/lib/libvirt/images/test.img 60 --shrink
error: invalid argument: storageVolumeResize: unsupported flags (0x4)
With the magic number "0x4", one'd never known what it is. It can
be improved roundabout, but it should be avoided in the beginning.
Regards,
Osier
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