fix(cache): use 512-byte units for stat.Blocks in FileSize

[levb]

stat.Blocks is reported in fixed 512-byte units per POSIX, not in the filesystem's optimal I/O block size. Multiplying by statfs Bsize (4096 on ext4) inflated the on-disk size by ~8x. Drop the Statfs call and multiply by the constant 512.

Verified locally that stat.Blocks * 512 matches the actual on-disk allocation while stat.Blocks * statfs.Bsize does not on ext4.

[gemini-code-assist]

Code Review

This pull request simplifies the FileSize method in cache.go by removing the call to syscall.Statfs and instead multiplying stat.Blocks by a constant of 512 bytes, in accordance with POSIX standards. It also inlines the error handling for syscall.Stat. There are no review comments, and I have no feedback to provide.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[codecov]

❌ 3 Tests Failed:

Tests completed	Failed	Passed	Skipped
2759	3	2756	7

View the full list of 3 ❄️ flaky test(s)

github.com/e2b-dev/infra/tests/integration/internal/tests/orchestrator::TestSandboxMemoryIntegrity

Flake rate in main: 53.93% (Passed 937 times, Failed 1097 times)

Stack Traces | 64.5s run time

=== RUN   TestSandboxMemoryIntegrity
=== PAUSE TestSandboxMemoryIntegrity
=== CONT  TestSandboxMemoryIntegrity
    sandbox_memory_integrity_test.go:27: Build completed successfully
--- FAIL: TestSandboxMemoryIntegrity (64.50s)

github.com/e2b-dev/infra/tests/integration/internal/tests/orchestrator::TestSandboxMemoryIntegrity/tmpfs_hash

Flake rate in main: 54.00% (Passed 927 times, Failed 1088 times)

Stack Traces | 199s run time

=== RUN   TestSandboxMemoryIntegrity/tmpfs_hash
=== PAUSE TestSandboxMemoryIntegrity/tmpfs_hash
=== CONT  TestSandboxMemoryIntegrity/tmpfs_hash
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{start:{pid:1257}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stdout:"Total memory: 985 MB\nUsed memory before tmpfs mount: 189 MB\nFree memory before tmpfs mount: 795 MB\nMemory to use in integrity test (60% of free, min 64MB): 477 MB\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"477+0 records in\n477+0 records out\n500170752 bytes (500 MB, 477 MiB) copied, 2.23621 s, 224 MB/s\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"\tCommand being timed: \"dd if=/dev/urandom of=/mnt/testfile bs=1M count=477\"\n\tUser time (seconds): 0.00\n\tSystem time (seconds): 2.22\n\tPercent of CPU this job got: 99%\n\tElapsed (wall clock) time (h:mm:ss or m:ss): 0:02.24\n\tAverage shared text size (kbytes): 0\n\tAverage unshared data size (kbytes): 0\n\tAverage stack size (kbytes): 0\n\tAverage total size (kbytes): 0\n\tMaximum resident set size (kbytes): 2704\n\tAverage resident set size (kbytes): 0\n\tMajor (requiring I/O) page faults: 3\n\tMinor (reclaiming a frame) page faults: 346\n\tVoluntary context switches: 4\n\tInvoluntary context switches: 10\n\tSwaps: 0\n\tFile system inputs: 176\n\tFile "}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"system outputs: 0\n\tSocket messag"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"es sent: "}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"0\n\tSoc"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"ket m"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"essag"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"es re"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"ceive"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"d: 0\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"\tSign"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"als d"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"elive"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"red: "}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"0\n\tP"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"age s"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"ize (bytes): 4096\n\tExit status: 0\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stdout:"Used memory after tmpfs mount and file fill: 671 MB\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{end:{exited:true  status:"exit status 0"}}
    sandbox_memory_integrity_test.go:70: Command [bash] completed successfully in sandbox idx1i27a8fz56qrlnjneb
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
    sandbox_memory_integrity_test.go:80: Command [bash] output: event:{start:{pid:1273}}
Executing command bash in sandbox if1uykkq36zz9uuj1fzz5 (user: root)
    sandbox_memory_integrity_test.go:80: Command [bash] output: event:{data:{stdout:"5023b0f5c6ed4726d35b48f0dd645338897821830b9dd797c5779de49dd9a840\n"}}
    sandbox_memory_integrity_test.go:80: Command [bash] output: event:{end:{exited:true  status:"exit status 0"}}
    sandbox_memory_integrity_test.go:80: Command [bash] completed successfully in sandbox idx1i27a8fz56qrlnjneb
    sandbox_memory_integrity_test.go:80: Command [bash] output: event:{start:{pid:1277}}
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
Executing command bash in sandbox idx1i27a8fz56qrlnjneb (user: root)
    sandbox_memory_integrity_test.go:110: 
        	Error Trace:	.../tests/orchestrator/sandbox_memory_integrity_test.go:81
        	            				.../hostedtoolcache/go/1.26.3.../src/runtime/asm_amd64.s:1771
        	Error:      	Received unexpected error:
        	            	failed to execute command bash in sandbox idx1i27a8fz56qrlnjneb: unavailable: HTTP status 502 Bad Gateway
    sandbox_memory_integrity_test.go:110: 
        	Error Trace:	.../tests/orchestrator/sandbox_memory_integrity_test.go:78
        	            				.../tests/orchestrator/sandbox_memory_integrity_test.go:110
        	Error:      	Condition never satisfied
        	Test:       	TestSandboxMemoryIntegrity/tmpfs_hash
--- FAIL: TestSandboxMemoryIntegrity/tmpfs_hash (198.68s)

github.com/e2b-dev/infra/tests/integration/internal/tests/proxies::TestSandboxAutoResumeViaProxy

Flake rate in main: 39.51% (Passed 931 times, Failed 608 times)

Stack Traces | 14.1s run time

=== RUN   TestSandboxAutoResumeViaProxy
=== PAUSE TestSandboxAutoResumeViaProxy
=== CONT  TestSandboxAutoResumeViaProxy
    auto_resume_test.go:97: [Status code: 502] Response body: {"sandboxId":"i9tlri2vkyzzt3gktfg1b","message":"The sandbox is running but port is not open","port":8000,"code":502}
Executing command cat in sandbox iyuyt6c0yeb5pxkddx9tw (user: root)
    auto_resume_test.go:116: 
        	Error Trace:	.../tests/proxies/auto_resume_test.go:116
        	Error:      	Received unexpected error:
        	            	Get "http://localhost:3002": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
        	Test:       	TestSandboxAutoResumeViaProxy
--- FAIL: TestSandboxAutoResumeViaProxy (14.11s)

To view more test analytics, go to the Test Analytics Dashboard
_{📋 Got 3 mins? Take this short survey to help us improve Test Analytics.}

[ValentaTomas]

One note—we use XFS for the actual cache in prod. Is that still the case with it?

[levb]

One note—we use XFS for the actual cache in prod. Is that still the case with it?

The man page, stack overflow the AI - all agree that 512 is a hardcoded, Linux-specific constant, not a property of the file system.

man page:

    .st_blocks
              This field indicates the number of blocks allocated to the
              file, in 512-byte units.  (This may be smaller than
              .st_size/512 when the file has holes.)

From my cluster's orchestrator (XFS confirmed)

lev@e2b-orch-client-3sz2:~$ sudo dd if=/dev/zero of=/orchestrator/_512test bs=1M count=10 conv=fsync
10+0 records in
10+0 records out
10485760 bytes (10 MB, 10 MiB) copied, 0.01238 s, 847 MB/s
lev@e2b-orch-client-3sz2:~$ stat /orchestrator/_512test
  File: /orchestrator/_512test
  Size: 10485760        Blocks: 20480      IO Block: 4096   regular file
Device: 9,0     Inode: 1157109     Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2026-06-09 16:44:02.001133545 +0000
Modify: 2026-06-09 16:44:02.006133891 +0000
Change: 2026-06-09 16:44:02.006133891 +0000
 Birth: 2026-06-09 16:44:02.001133545 +0000
lev@e2b-orch-client-3sz2:~$ du -B1 /orchestrator/_512test
10485760        /orchestrator/_512test
lev@e2b-orch-client-3sz2:~$ 

Notice Blocks: 20480 for the 10Mb file despite the IO Block size