vfs: return EOPNOTSUPP for FICLONE/FICLONERANGE/FIDEDUPERANGE#12853
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copybara-service[bot] merged 1 commit intogoogle:masterfrom Apr 3, 2026
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vfs: return EOPNOTSUPP for FICLONE/FICLONERANGE/FIDEDUPERANGE#12853copybara-service[bot] merged 1 commit intogoogle:masterfrom
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Linux returns EOPNOTSUPP when a filesystem does not support reflink. gVisor returned ENOTTY, breaking programs like syncthing that rely on EOPNOTSUPP to gracefully fall back to regular copy. Handle these ioctls in FileDescriptionDefaultImpl.Ioctl() so all filesystems without custom Ioctl get the correct errno automatically. Signed-off-by: Tan Yifeng <yiftan@tencent.com>
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Linux returns EOPNOTSUPP when a filesystem does not support reflink. gVisor returned ENOTTY, breaking programs like syncthing that rely on EOPNOTSUPP to gracefully fall back to regular copy. Handle these ioctls in FileDescriptionDefaultImpl.Ioctl() so all filesystems without custom Ioctl get the correct errno automatically. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12853 from tanyifeng:vfs-ficlone-eopnotsupp 7435a6c PiperOrigin-RevId: 893757418
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Linux returns EOPNOTSUPP when a filesystem does not support reflink. gVisor returned ENOTTY, breaking programs like syncthing that rely on EOPNOTSUPP to gracefully fall back to regular copy. Handle these ioctls in FileDescriptionDefaultImpl.Ioctl() so all filesystems without custom Ioctl get the correct errno automatically. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12853 from tanyifeng:vfs-ficlone-eopnotsupp 7435a6c PiperOrigin-RevId: 893757418
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| INSTANTIATE_TEST_SUITE_P(IoctlTest, IoctlTestSIOCGIFCONF, | ||
| ::testing::ValuesIn(IoctlSocketTypes())); | ||
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| // FICLONE/FICLONERANGE/FIDEDUPERANGE should return EOPNOTSUPP on |
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These tests will fail when run on Linux. IMO syscall test is not required for this change. We primarliy use them to compare gVisor <-> Linux compatibility.
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You're right — I realized that on filesystems that support reflink, these ioctls would succeed instead of returning EOPNOTSUPP, so the tests could indeed fail on native Linux depending on the filesystem. I've send a follow-up pr #12863 to remove these test cases. Thanks for catching this!
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Remove the EOPNOTSUPP test cases for FICLONE, FICLONERANGE, and FIDEDUPERANGE ioctls added in google#12853 These tests assume the ioctls always fail with EOPNOTSUPP, which is only true on filesystems that do not support reflink, causing the tests to fail on native Linux. Signed-off-by: Tan Yifeng <yiftan@tencent.com>
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Remove the EOPNOTSUPP test cases for FICLONE, FICLONERANGE, and FIDEDUPERANGE ioctls added in #12853 These tests assume the ioctls always fail with EOPNOTSUPP, which is only true on filesystems that do not support reflink, causing the tests to fail on native Linux. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12863 from tanyifeng:remove-ficlone-tests e1e815c PiperOrigin-RevId: 893842986
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Linux returns EOPNOTSUPP when a filesystem does not support reflink. gVisor returned ENOTTY, breaking programs like syncthing that rely on EOPNOTSUPP to gracefully fall back to regular copy.
Handle these ioctls in FileDescriptionDefaultImpl.Ioctl() so all filesystems without custom Ioctl get the correct errno automatically.