TrueCloudLab/rclone
16
0
Fork 4
Code Issues 1 Pull requests Projects Releases 4 Packages Wiki Activity Actions

azureblob: fix data corruption bug #7590

Browse source 
It was reported that rclone copy occasionally uploaded corrupted data
to azure blob.

This turned out to be a race condition updating the block count which
caused blocks to be duplicated.

This bug was introduced in this commit in v1.64.0 and will be fixed in v1.65.2

0427177857 azureblob: implement OpenChunkWriter and multi-thread uploads #7056

This race only seems to happen if `--checksum` is used but can happen otherwise.

Unfortunately Azure blob does not check the MD5 that we send them so
despite sending incorrect data this corruption is not detected. The
corruption is detected when rclone tries to download the file, so
attempting to copy the files back to local disk will result in errors
such as:

    ERROR : file.pokosuf5.partial: corrupted on transfer: md5 hash differ "XXX" vs "YYY"

This adds a check to test the blocklist we upload is as we expected
which would have caught the problem had it been in place earlier.
This commit is contained in:
Nick Craig-Wood 2024-01-23 09:53:47 +00:00
parent b3a1f66759
commit 03295bbc3c
2 changed files with 25 additions and 43 deletions
Download patch file Download diff file Expand all files Collapse all files

18
backend/azureblob/azureblob_internal_test.go
View file

@ -17,21 +17,3 @@ func (f *Fs) InternalTest(t *testing.T) {
enabled = f.Features().GetTier
assert.True(t, enabled)
}
func TestIncrement(t *testing.T) {
for _, test := range []struct {
in [8]byte
want [8]byte
}{
{[8]byte{0, 0, 0, 0}, [8]byte{1, 0, 0, 0}},
{[8]byte{0xFE, 0, 0, 0}, [8]byte{0xFF, 0, 0, 0}},
{[8]byte{0xFF, 0, 0, 0}, [8]byte{0, 1, 0, 0}},
{[8]byte{0, 1, 0, 0}, [8]byte{1, 1, 0, 0}},
{[8]byte{0xFF, 0xFF, 0xFF, 0xFE}, [8]byte{0, 0, 0, 0xFF}},
{[8]byte{0xFF, 0xFF, 0xFF, 0xFF}, [8]byte{0, 0, 0, 0, 1}},
{[8]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, [8]byte{0, 0, 0, 0, 0, 0, 0}},
} {
increment(&test.in)
assert.Equal(t, test.want, test.in)
}
}