nydus-image: Fix blob unpacking bug in specified blob directory

[An-DJ]

Relevant Issue (if applicable)

Close #1340

Details

Fix the unpack bug in multi blobs situation. (Based on the unmerged work in #1338)

Types of changes

What types of changes does your PullRequest introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

Go over all the following points, and put an x in all the boxes that apply.

• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #1426 (b48b662) into master (278915b) will decrease coverage by 0.02%.
The diff coverage is 31.48%.

@@            Coverage Diff             @@
##           master    #1426      +/-   ##
==========================================
- Coverage   46.45%   46.44%   -0.02%     
==========================================
  Files         123      123              
  Lines       38640    38702      +62     
  Branches    38640    38702      +62     
==========================================
+ Hits        17951    17975      +24     
- Misses      19714    19753      +39     
+ Partials      975      974       -1     

Files Changed	Coverage Δ
rafs/src/metadata/cached_v5.rs	58.52% <0.00%> (-0.98%)	⬇️
rafs/src/metadata/direct_v5.rs	56.44% <ø> (ø)
rafs/src/metadata/direct_v6.rs	6.48% <0.00%> (-0.07%)	⬇️
rafs/src/metadata/inode.rs	47.50% <0.00%> (ø)
rafs/src/metadata/mod.rs	52.28% <ø> (-0.58%)	⬇️
rafs/src/mock/mock_inode.rs	0.00% <0.00%> (ø)
src/bin/nydus-image/main.rs	41.78% <0.00%> (-0.12%)	⬇️
src/bin/nydus-image/unpack/mod.rs	0.00% <0.00%> (ø)
src/bin/nydus-image/unpack/pax.rs	9.74% <62.96%> (+1.90%)	⬆️
src/bin/nydus-image/unpack/pax/test.rs	89.72% <100.00%> (+2.59%)	⬆️

... and 1 file with indirect coverage changes

[An-DJ]

Follow the steps in #1340 to reproduce that issue and verify if it is fixed:

1. Prepare the data:

# create a directory to store only one file `echarts.png`
mkdir echarts

# create a directory to store two file `avatar.png` and `echarts.png`
mkdir echarts-add

# create a directory to store created images (meta, blob)
mkdir echarts-image

# download images
wget https://user-images.githubusercontent.com/1655233/249319028-009b32a0-1563-465c-867e-7623d1b9275d.png -O echarts/echarts.png
wget https://user-images.githubusercontent.com/1655233/249319027-5dcdaf14-631c-46c4-ac11-58b1d4c04a0f.png -O echarts-add/avatar.png
wget https://user-images.githubusercontent.com/1655233/249319028-009b32a0-1563-465c-867e-7623d1b9275d.png -O echarts-add/echarts.png

2. Create the first one

./nydus-image create -v 5 -t dir-rafs -D echarts-image echarts
[2023-09-17 15:10:14.890232 +00:00] INFO successfully built RAFS filesystem:
meta blob path: echarts-image/59016ae5c245fd768f85cf6eeab74da0d88cd00d9f2df5d3627e6f0177ba38d9
data blob size: 0xc0e1
data blobs: ["fa964c10cd36503b3bbd0d8218ec03d132214a51b0e4b03d2684770290306bce"]

3. Create the second one

./nydus-image create -v 5 -t dir-rafs --chunk-dict echarts-image/59016ae5c245fd768f85cf6eeab74da0d88cd00d9f2df5d3627e6f0177ba38d9 -D echarts-image echarts-add
[2023-09-17 15:12:04.145951 +00:00] INFO RAFS v5 super block features: HASH_BLAKE3 | EXPLICIT_UID_GID | COMPRESSION_ZSTD
[2023-09-17 15:12:04.153042 +00:00] INFO successfully built RAFS filesystem:
meta blob path: echarts-image/86235ef91901df9392244c0f973c118530519f5b932bed33671aa9775e45a5e9
data blob size: 0xc0e1
data blobs: ["5ee38535110c9470daeb434efbace48b15dfb7c08878cc9effa2bc0b29638a0d", "fa964c10cd36503b3bbd0d8218ec03d132214a51b0e4b03d2684770290306bce"]

4. Do unpack

./nydus-image unpack --blob-dir echarts-image --output ./unpack-files.tar echarts-image/86235ef91901df9392244c0f973
c118530519f5b932bed33671aa9775e45a5e9
[2023-09-17 15:13:23.384728 +00:00] INFO RAFS v5 super block features: HASH_BLAKE3 | EXPLICIT_UID_GID | COMPRESSION_ZSTD

5. Untar file and compare the checksum:

$ tar xvf unpack-files.tar
avatar.png
echarts.png

$ md5sum avatar.png
8d852403b0badc7731e8b5aa7bd3ad36  avatar.png
$ md5sum echarts-add/avatar.png
8d852403b0badc7731e8b5aa7bd3ad36  echarts-add/avatar.png

$ md5sum echarts.png
c747eb230ad3439052e001187b6a216d  echarts.png
$ md5sum echarts-add/echarts.png
c747eb230ad3439052e001187b6a216d  echarts-add/echarts.png

[imeoer]

Great job, thanks for the PR!

[adamqqqplay]

Please organize your commits before merging. Our repo uses rebase merging, which will submit your original commit information to the master branch.

[An-DJ]

Please organize your commits before merging. Our repo uses rebase merging, which will submit your original commit information to the master branch.

@adamqqqplay Done.

[imeoer]

others LGTM! Thanks!