mv: support moving folder containing symlinks to different filesystem

[yuankunzhang]

Closes #8586.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/misc/stdbuf (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

[codspeed-hq]

CodSpeed Performance Report

Merging #8605 will not alter performance

_{Comparing yuankunzhang:mv-folder-containing-symlinks-across-fs (35848e2) with main (1eea517)}

Summary

✅ 136 untouched
⏩ 24 skipped¹

Footnotes

1. 24 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)

[oech3]

Should we share codebase with cp -a instead?
It should fix #9458 automatically

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

[oech3]

Would you merge this at fix 1 bug at a monent? sudo test issue is traced at different PR and difficult to fix at here.

[oech3]

Would you merge this?

[oech3]

@yuankunzhang @ChrisDryden Would you test mkdir /tmp/{a,b}; unshare -rm bash -c "mount -t tmpfs tmpfs /tmp/a && mount -t tmpfs tmpfs /tmp/b && mkdir -p /tmp/a/d && ln -sv miss /tmp/a/d/dang && mv -v /tmp/a/d /tmp/b" without sudo?

[oech3]

The job has exceeded the maximum execution time while awaiting a runner for 24h0m0s

[oech3]

ok to merge this pr?

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/tty/tty-eof. tests/tty/tty-eof is passing on 'main'. Maybe you have to rebase?

[oech3]

Thanyou!

[oech3]

Still mv: Operation not supported (os error 95) for me. Maybe, dir on compressed btrfs specific?