feat: Use inode quota in volume size

[rolysr]

This commit incorporates the quota assigned to a directory into the calculation of the current available space. This change improves the consistency of quota configuration across users, groups, and folders.

[gemini-code-assist]

Hello @rolysr, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

Summary of Changes

This pull request modifies the fs_get_self_quota function to include inode quota in the calculation of available space. It updates the function signature in both mastercomm.h and mastercomm.cc to accept an inode parameter. The statfs function in sauna_client.cc is updated to retrieve and incorporate inode quota information when gUseQuotaInVolumeSize is enabled. Additionally, a test case is added to test_use_quota_in_volume_size.sh to verify the behavior of folder quotas.

Highlights

• Inode Quota Inclusion: The primary goal is to incorporate inode quota into the available space calculation, providing a more consistent quota management experience.
• Function Signature Update: The fs_get_self_quota function now accepts an inode parameter, allowing it to fetch quota information specific to an inode.
• Quota Retrieval and Application: The statfs function in sauna_client.cc now retrieves inode quota information and uses it to adjust the available space calculation.
• Test Case Addition: A new test case has been added to verify the correct behavior of folder quotas, ensuring that inode quotas are properly enforced.

Changelog

Click here to see the changelog

• src/mount/mastercomm.cc
  • Modified fs_get_self_quota function to accept an inode parameter on line 3122.
  • Added QuotaOwnerType::kInode to the requested entities on line 3130.
• src/mount/mastercomm.h
  • Updated the signature of fs_get_self_quota to include the inode parameter on line 124.
• src/mount/sauna_client.cc
  • Modified statfs function to include inode quota on line 719.
  • Added logic to retrieve and apply inode quota information on lines 751-760.
  • Adjusted the calculation of availspace to include inodeAvailSpace on line 770.
• tests/test_suites/ShortSystemTests/test_use_quota_in_volume_size.sh
  • Added a test case to verify folder quota behavior on lines 76-90.
  • Added commands to increase user and group quotas, then decrease the inode quota for the root directory.

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---

Trivia time!

What is the purpose of an inode in a file system?

Click here for the answer

An inode (index node) is a data structure in a file system that stores metadata about a file, such as its permissions, owner, size, and the location of its data blocks on disk.

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[gemini-code-assist]

Code Review

This commit introduces inode quota support to the volume size calculation, enhancing quota consistency. The changes look good overall, but there are a few areas that could be improved for clarity and robustness.

Summary of Findings

• Error Handling in Quota Retrieval: The code currently throws a generic exception when quota retrieval fails, which might not be the most informative approach. Consider providing more context or specific error codes to aid in debugging.
• Redundant Variable Initialization: The variables userUsedSpace, groupUsedSpace, and inodeUsedSpace are initialized to 0 and then immediately potentially overwritten by entry.limit. Consider initializing them directly with entry.limit if the quota entry is found, or keeping the initial value if not.
• Test Coverage: The new test case only checks for zero available space after setting an inode quota. It would be beneficial to add tests that verify the available space is correctly calculated for non-zero inode quotas.

Merge Readiness

The pull request is almost ready for merging. Addressing the error handling and variable initialization concerns would improve the code's robustness and readability. The test coverage could also be expanded to provide more confidence in the correctness of the changes. I am unable to directly approve this pull request, and recommend that others review and approve this code before merging. At a minimum, the HIGH severity comment should be addressed before merging.

[aNeutrino]

Sure! Here are some additional test cases for directory-based quota:

1. Test Increasing Directory Quota Beyond User Quota:
   • Create a folder with a quota less than the user quota.
   • Verify the folder quota is enforced.
   • Increase the folder quota to exceed the user quota.
   • Verify the user quota is still enforced and the folder quota increase does not take effect.

# Create a folder with a quota of 1/2 user_limit
mkdir folder2
saunafs setquota -d 0 $((user_limit / 2)) 0 0 folder2

# Verify folder quota is enforced
cd folder2
assert_success sudo -nu saunafstest_1 dd if=/dev/zero of=file4 bs=1M count=$((user_limit_mb / 2))
assert_fail sudo -nu saunafstest_1 dd if=/dev/zero of=file4 bs=1M count=$((user_limit_mb))

# Increase folder quota to exceed user quota
saunafs setquota -d 0 $((2 * user_limit)) 0 0 folder2

# Verify user quota is enforced
assert_fail sudo -nu saunafstest_1 dd if=/dev/zero of=file4 bs=1M count=$((user_limit_mb))
cd -

2. Test Directory Quota on Nested Directories:
   • Create nested folders with different quotas.
   • Verify the quotas are correctly enforced at each level.

# Create nested folders with different quotas
mkdir -p folder3/subfolder1
saunafs setquota -d 0 $((user_limit * 3 / 4)) 0 0 folder3
saunafs setquota -d 0 $((user_limit / 2)) 0 0 folder3/subfolder1

# Verify quotas are enforced at each level
cd folder3
assert_success sudo -nu saunafstest_1 dd if=/dev/zero of=file5 bs=1M count=$((user_limit_mb / 2))
cd subfolder1
assert_success sudo -nu saunafstest_1 dd if=/dev/zero of=file6 bs=1M count=$((user_limit_mb / 4))
assert_fail sudo -nu saunafstest_1 dd if=/dev/zero of=file6 bs=1M count=$((user_limit_mb / 2))
cd -
cd -

3. Test Decreasing Directory Quota:
   • Create a folder and fill it up to its quota.
   • Decrease the folder quota and verify that writing further data fails.

# Create a folder and fill it up to its quota
mkdir folder4
saunafs setquota -d 0 $((user_limit / 2)) 0 0 folder4
cd folder4
assert_success sudo -nu saunafstest_1 dd if=/dev/zero of=file7 bs=1M count=$((user_limit_mb / 2))

# Decrease the folder quota
saunafs setquota -d 0 $((user_limit / 4)) 0 0 folder4

# Verify writing further data fails
assert_fail sudo -nu saunafstest_1 dd if=/dev/zero of=file8 bs=1M count=$((user_limit_mb / 2))
cd -

4. Test Directory Quota with Different Users:
   • Create a folder and set a quota.
   • Verify that the quota is enforced for different users.

# Create a folder and set a quota
mkdir folder5
saunafs setquota -d 0 $((user_limit / 2)) 0 0 folder5
cd folder5

# Verify the quota is enforced for different users
assert_success sudo -nu saunafstest_1 dd if=/dev/zero of=file9 bs=1M count=$((user_limit_mb / 4))
assert_fail sudo -nu saunafstest_2 dd if=/dev/zero of=file10 bs=1M count=$((user_limit_mb / 2))
cd -

5. Test Directory Quota with Different Groups:
   • Create a folder and set a quota.
   • Verify that the quota is enforced for different groups.

# Create a folder and set a quota
mkdir folder6
saunafs setquota -d 0 $((user_limit / 2)) 0 0 folder6
cd folder6

# Verify the quota is enforced for different groups
assert_success sudo -nu saunafstest_1 dd if=/dev/zero of=file11 bs=1M count=$((user_limit_mb / 4))
assert_fail sudo -nu saunafstest_1 chgrp othergroup file11
assert_fail sudo -nu saunafstest_2 dd if=/dev/zero of=file12 bs=1M count=$((user_limit_mb / 2))
cd -

These test cases will help ensure that the directory-based quota system works correctly under various conditions.

[dmga44]

As a minor change, I'd liketo propose to use the inode used space (the space occupied by the folder) as the mount used space.

Currently it is showing the user's used space, which might not be the desired one or expected one, could be even confusing. I think it all depends of the use case this option is intended for.

[antuan96314]

LGTM