Date: Fri, 6 Nov 2009 18:23:08 +0100 From: Gary Jennejohn <gary.jennejohn@freenet.de> To: Alexander Best <alexbestms@math.uni-muenster.de> Cc: freebsd-hackers@FreeBSD.org, Alex Dupre <ale@FreeBSD.org> Subject: Re: rmdir(2) and mkdir(2) both return EISDIR for argument "/" Message-ID: <20091106182308.14dffc50@ernst.jennejohn.org> In-Reply-To: <permail-2009110616430680e26a0b000006fe-a_best01@message-id.uni-muenster.de> References: <20091106170853.7d0b0b6f@ernst.jennejohn.org> <permail-2009110616430680e26a0b000006fe-a_best01@message-id.uni-muenster.de>
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On Fri, 06 Nov 2009 17:43:06 +0100 (CET) Alexander Best <alexbestms@math.uni-muenster.de> wrote: > Gary Jennejohn schrieb am 2009-11-06: > > On Fri, 06 Nov 2009 16:32:22 +0100 (CET) > > Alexander Best <alexbestms@math.uni-muenster.de> wrote: > > > > Alex Dupre schrieb am 2009-11-06: > > > > Alexander Best ha scritto: > > > > > i dug up this old pr > > > > > http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/59739 > > > > > I think the EISDIR error is coming from kern/vfs_lookup.c, > > > > lookup() > > > > function with cn_nameptr = "": > > > > > > /* > > > > * Check for degenerate name (e.g. / or "") > > > > * which is a way of talking about a directory, > > > > * e.g. like "/." or ".". > > > > */ > > > > if (cnp->cn_nameptr[0] == '\0') { > > > > ... > > > > if (cnp->cn_nameiop != LOOKUP) { > > > > error = EISDIR; > > > > goto bad; > > > > } > > > > ... > > > > thanks a lot for finding the problem in the src. what do you think > > > of the > > > patch attached to this message? after applying it the example code > > > i posted in > > > my previous message returns the following output (instead of > > > EISDIR): > > > > rmdir errno: 16 (which is EBUSY) > > > mkdir errno: 17 (which is EEXIST) > > > > i don't know if these really are the correct return values, but > > > it's what the > > > originator of the PR requested. > > > > What if cn_nameiop is != LOOKUP but also neither DELETE nor CREATE, > > assuming that case is possible? I'd leave the original if-clause at > > the end to catch that. > > > --- > > Gary Jennejohn > > how about this patch? > > 1. i've added "if (cnp->cn_nameiop != LOOKUP)" although i don't think it's > necessary since the first blocks should cover all the possible cases. > 2. i've used rename() to test the case (cnp->cn_nameiop != RENAME). is this > correct or does rename() use a combo of DELETE and CREATE? problem is that the > rename(2) manual doesn't seem to cover the case that arg 1 is a mountpoint. > right now EBUSY gets returned if cnp->cn_nameiop != RENAME. however BUSY needs > to be added to all manuals which use cnp->cn_nameiop != RENAME (shouldn't be > too many). or are there any other suggestions what rename() should return if > arg 1 is a mountpoint? > Hmm. In rename(2) there's [EINVAL] The from argument is a parent directory of to, or an attempt is made to rename `.' or `..'. and a few lines below your patch this case is handled for ISDOTDOT for both RENAME and DELETE. I don't see off hand where renaming or deleting "." is handled. According to the comment above your patch the case of "/." or "." is being checked, which would seem to correspond to the above part of rename(2), i.e. perhaps EINVAL should be returned for RENAME and DELETE. --- Gary Jennejohn
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