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author | Dmitry Tantsur <dtantsur@protonmail.com> | 2023-03-31 15:39:50 +0200 |
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committer | Dmitry Tantsur <dtantsur@protonmail.com> | 2023-03-31 15:49:15 +0200 |
commit | 59c6ad96ce35c9deecfedb5698c5806f3883a8af (patch) | |
tree | 80b9eff0322e3a6ac7002e8cfb03c74ea2590bc5 /ironic/common | |
parent | abbd859b766c339f5de33ff08704a7b9ad045bef (diff) | |
download | ironic-59c6ad96ce35c9deecfedb5698c5806f3883a8af.tar.gz |
Always fall back from hard linking to copying files
The current check is insufficient: it passes for Kubernetes shared
volumes, although hard-linking between them is not possible.
This patch changes the approach to trying a hard link and falling
back to copyfile instead.
The patch relies on optimizations in Python 3.8 and thus should not
be backported beyond the Zed series to avoid performance regression.
Change-Id: I929944685b3ac61b2f63d2549198a2d8a1c8fe35
Diffstat (limited to 'ironic/common')
-rw-r--r-- | ironic/common/image_service.py | 35 |
1 files changed, 14 insertions, 21 deletions
diff --git a/ironic/common/image_service.py b/ironic/common/image_service.py index 5280ee6bc..4b95b5152 100644 --- a/ironic/common/image_service.py +++ b/ironic/common/image_service.py @@ -34,10 +34,6 @@ from ironic.common import utils from ironic.conf import CONF IMAGE_CHUNK_SIZE = 1024 * 1024 # 1mb -# NOTE(kaifeng) Image will be truncated to 2GiB by sendfile, -# we use a large chunk size here for a better performance -# while keep the chunk size less than the size limit. -SENDFILE_CHUNK_SIZE = 1024 * 1024 * 1024 # 1Gb LOG = log.getLogger(__name__) @@ -264,26 +260,23 @@ class FileImageService(BaseImageService): """ source_image_path = self.validate_href(image_href) dest_image_path = image_file.name - local_device = os.stat(dest_image_path).st_dev try: - # We should have read and write access to source file to create - # hard link to it. - if (local_device == os.stat(source_image_path).st_dev - and os.access(source_image_path, os.R_OK | os.W_OK)): - image_file.close() - os.remove(dest_image_path) + image_file.close() + os.remove(dest_image_path) + + try: os.link(source_image_path, dest_image_path) + except OSError as exc: + LOG.debug('Could not create a link from %(src)s to %(dest)s, ' + 'will copy the content instead. Error: %(exc)s.', + {'src': source_image_path, 'dest': dest_image_path, + 'exc': exc}) else: - filesize = os.path.getsize(source_image_path) - offset = 0 - with open(source_image_path, 'rb') as input_img: - while offset < filesize: - count = min(SENDFILE_CHUNK_SIZE, filesize - offset) - nbytes_out = os.sendfile(image_file.fileno(), - input_img.fileno(), - offset, - count) - offset += nbytes_out + return + + # NOTE(dtantsur): starting with Python 3.8, copyfile() uses + # efficient copying (i.e. sendfile) under the hood. + shutil.copyfile(source_image_path, dest_image_path) except Exception as e: raise exception.ImageDownloadFailed(image_href=image_href, reason=str(e)) |