Federico Simoncelli has uploaded a new change for review.
Change subject: [wip] volume: make volume._share idempotent
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[wip] volume: make volume._share idempotent
With this patch it will possible to run the volume._share command
multiple times without harm (idempotent) for the image and for the
running VMs.
Signed-off-by: Federico Simoncelli <fsimonce(a)redhat.com>
Change-Id: I237e4a8f094ba04dcd4ef7bff418e03f81162d8d
---
M vdsm/storage/blockVolume.py
M vdsm/storage/fileVolume.py
M vdsm/storage/volume.py
3 files changed, 39 insertions(+), 16 deletions(-)
git pull ssh://gerrit.ovirt.org:29418/vdsm refs/changes/70/8270/1
diff --git a/vdsm/storage/blockVolume.py b/vdsm/storage/blockVolume.py
index 38285c1..ee8ba67 100644
--- a/vdsm/storage/blockVolume.py
+++ b/vdsm/storage/blockVolume.py
@@ -324,6 +324,7 @@
dstPath = os.path.join(dstImgPath, self.volUUID)
self.log.debug("Share volume %s to %s", self.volUUID, dstImgPath)
+ # TODO: make this idempotent
os.symlink(self.getDevPath(), dstPath)
@classmethod
diff --git a/vdsm/storage/fileVolume.py b/vdsm/storage/fileVolume.py
index 0aa9043..2e76944 100644
--- a/vdsm/storage/fileVolume.py
+++ b/vdsm/storage/fileVolume.py
@@ -227,29 +227,49 @@
"""
Share this volume to dstImgPath, including the metadata and the lease
"""
- dstVolPath = os.path.join(dstImgPath, self.volUUID)
- dstMetaPath = self._getMetaVolumePath(dstVolPath)
-
self.log.debug("Share volume %s to %s", self.volUUID, dstImgPath)
- self.oop.fileUtils.safeUnlink(dstVolPath)
- self.oop.os.link(self.getVolumePath(), dstVolPath)
+ dstVolumePath = os.path.join(dstImgPath, self.volUUID)
- self.log.debug("Share volume metadata of %s to %s", self.volUUID,
- dstImgPath)
+ # Format: itemName, srcPath, dstPath, itemRequired
+ itemsList = [
+ ('volume', self.getVolumePath(), dstVolumePath, True),
+ ('metadata', self._getMetaVolumePath(),
+ self._getMetaVolumePath(dstVolumePath), True),
+ ('lease', self._getLeaseVolumePath(),
+ self._getLeaseVolumePath(dstVolumePath),
+ sdCache.produce(self.sdUUID).hasVolumeLeases()),
+ ]
- self.oop.fileUtils.safeUnlink(dstMetaPath)
- self.oop.os.link(self._getMetaVolumePath(), dstMetaPath)
+ for itemName, srcPath, dstPath, itemRequired in itemsList:
+ self.log.debug("Sharing %s %s to %s (required: %s)", itemName,
+ self.volUUID, dstPath, itemRequired)
- # Link the lease file if the domain uses sanlock
- if sdCache.produce(self.sdUUID).hasVolumeLeases():
- dstLeasePath = self._getLeaseVolumePath(dstVolPath)
+ try:
+ srcInfo = self.oop.stat(srcPath)
+ except OSError, e:
+ if e != os.errno.ENOENT or itemRequired:
+ # Source not found
+ self.log.debug("TODO: <message>")
+ raise
- self.log.debug("Share volume lease of %s to %s", self.volUUID,
- dstImgPath)
+ try:
+ dstInfo = self.oop.stat(dstPath)
+ except OSError, e:
+ if e != os.errno.ENOENT:
+ raise
- self.oop.fileUtils.safeUnlink(dstLeasePath)
- self.oop.os.link(self._getLeaseVolumePath(), dstLeasePath)
+ # Destination file not present, linking
+ self.log.debug("TODO: <message>")
+ self.oop.os.link(srcPath, dstPath)
+ else:
+ # If both the source and destination are present and they are
+ # the same file (already linked) then continue.
+ if srcInfo.st_ino == dstInfo.st_ino:
+ self.log.debug("TODO: <message>")
+ else:
+ self.log.debug("TODO: <message>")
+ raise OSError(os.errno.EEXIST, "Destination file exists")
@classmethod
def shareVolumeRollback(cls, taskObj, volPath):
diff --git a/vdsm/storage/volume.py b/vdsm/storage/volume.py
index b9eb356..7938c6f 100644
--- a/vdsm/storage/volume.py
+++ b/vdsm/storage/volume.py
@@ -297,6 +297,8 @@
self._share(dstImgPath)
except Exception, e:
+ self.log.debug("Cannot share volume %s to %s", self.volUUID,
+ dstImgPath, exc_info=True)
raise se.CannotShareVolume(self.getVolumePath(), dstPath, str(e))
def refreshVolume(self):
--
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I237e4a8f094ba04dcd4ef7bff418e03f81162d8d
Gerrit-PatchSet: 1
Gerrit-Project: vdsm
Gerrit-Branch: master
Gerrit-Owner: Federico Simoncelli <fsimonce(a)redhat.com>