Passed flag freezes fsck.f2fs

[aerkiaga]

Observed behavior

Running fsck.f2fs -p* [device], where * is any sequence of non-spaces with at least a non-digit character, freezes fsck.f2fs. It enters an infinite loop, printing Info: Use default preen mode continuously. CPU usage is increased, but there's no disk activity and used up RAM is constant.

This could be a problem if the user wants to pass multiple flags (e.g. -pf, which should be valid) or they misinterpret the syntax. Other combined options like -ap, -fp or -fS work perfectly. Contrast this with -pf.

Note: this only happens with -p, not with -d.

Tests performed

1.13.0

On this version I've verified that -pf creates an infinite loop. I haven't tested other combinations.

1.11.0

On this version I've tested all of -pf, -pa, -py, -pp, -p3a, p*, -p-, -p$, -p%, -p., -p123 and -pbhydfs. All of them raise an infinite loop, printing the same message over and over.

Intended behavior

-p<option> should work like -<option>p, and -p<garbage> like -<option><garbage>.

Summary

Option	Actual	Expected
-p<option>	Freeze	-p -<option>
-<option><option>	-<option> -<option>	(expected)
-p<garbage>	Freeze	Syntax error
-<option><garbage>	Syntax error	(expected)
-<garbage>	Syntax error	(expected)