[Rd] Improper directory removal causes file system havoc (PR#11747)

[ripley at stats.ox.ac.uk]

This is not general on Solaris 10 -- it works for others, as the R-admin 
manual told you.

What sort of file system is the test being run on?

It does look very like a Solaris file system bug.

On Wed, 18 Jun 2008, mjbauer at eecs.tufts.edu wrote:

> Full_Name: Michael Bauer
> Version: 2.7.0
> OS: Solaris 10 (sparc)
> Submission from: (NULL) (130.64.21.7)
>
>
> When running 'make check' on a fresh R 2.7.0 build on Solaris 10 (sparc),
> reg-tests-1.R fails consistently because the test directory /tmp/R<random>
> cannot be deleted.  The reason for the deletion failure is because the file
> system thinks that the directory is still full, as its link count is not 2 -- it
> is 5.  The key bit of reg-tests-1.R is:
>
> dd <- c("dir1", "dir2", "dirs", "moredirs")
> for(d in dd) dir.create(d)
> dir(".")
> file.create(file.path(dd, "somefile"))
> dir(".", recursive=TRUE)
> stopifnot(unlink("dir?") == 1) # not an error
> unlink("dir?", recursive = TRUE)
> stopifnot(file.exists(dd) == c(FALSE, FALSE, FALSE, TRUE))
> unlink("*dir*", recursive = TRUE)
> stopifnot(!file.exists(dd))
>
> I've run this code snippet in the R command line.  The initial state of the
> directory is:
>
> root at sunfire16# mkdir testdir
> root at sunfire16# cd testdir
> root at sunfire16# ls -al
> total 34
> drwx------   2 root          512 Jun 18 16:12 .
> drwxrwxrwt  18 root        33280 Jun 18 16:12 ..
>
>
> After the file.create command, the directory state is:
>
> root at sunfire16# ls -al
> total 38
> drwx------   6 root          512 Jun 18 16:13 .
> drwxrwxrwt  19 root        33280 Jun 18 16:13 ..
> drwx------   2 root          512 Jun 18 16:13 dir1
> drwx------   2 root          512 Jun 18 16:13 dir2
> drwx------   2 root          512 Jun 18 16:13 dirs
> drwx------   2 root          512 Jun 18 16:13 moredirs
> root at sunfire16# ls -al *
> dir1:
> total 2
> drwx------   2 root          512 Jun 18 16:13 .
> drwx------   6 root          512 Jun 18 16:13 ..
> -rw-------   1 root            0 Jun 18 16:13 somefile
>
> dir2:
> total 2
> drwx------   2 root          512 Jun 18 16:13 .
> drwx------   6 root          512 Jun 18 16:13 ..
> -rw-------   1 root            0 Jun 18 16:13 somefile
>
> dirs:
> total 2
> drwx------   2 root          512 Jun 18 16:13 .
> drwx------   6 root          512 Jun 18 16:13 ..
> -rw-------   1 root            0 Jun 18 16:13 somefile
>
> moredirs:
> total 2
> drwx------   2 root          512 Jun 18 16:13 .
> drwx------   6 root          512 Jun 18 16:13 ..
> -rw-------   1 root            0 Jun 18 16:13 somefile
>
>
> However, immediately after the unlink("dir?") command, the directory state is
> incorrect.  Note that in addition to dir1, dir2, and dirs being missing, the
> link count on the parent directory is still 6, not 3.
>
> root at sunfire16# ls -al
> total 35
> drwx------   6 root          512 Jun 18 16:13 .
> drwxrwxrwt  20 root        33280 Jun 18 16:20 ..
> drwx------   2 root          512 Jun 18 16:13 moredirs
> root at sunfire16# ls -al *
> total 2
> drwx------   2 root          512 Jun 18 16:13 .
> drwx------   6 root          512 Jun 18 16:13 ..
> -rw-------   1 root            0 Jun 18 16:13 somefile
>
>
> Once the rest of the code runs, the directory state is still incorrect, with the
> link count on a now-empty directory still being 5 instead of 2:
>
> root at sunfire16# ls -al
> total 34
> drwx------   5 root          512 Jun 18 16:23 .
> drwxrwxrwt  20 root        33280 Jun 18 16:20 ..
>
>
> The directory now cannot be removed, either within R or by hand in the shell:
>
> root at sunfire16# cd ..
> root at sunfire16# rmdir testdir
> rmdir: directory "testdir": Directory not empty
>
>
> The only thing I've found to fix this is unmounting the file system and running
> fsck on it.  This finds the mis-deleted directories and fixes the broken link
> counts.
>
> I'm not certain if this is a bug in R or in Solaris, though it certainly looks
> like a Solaris bug.  I have submitted the bug to both you and Solaris.
>
> I also have truss output from a run of this, which shows R using a mix of
> unlink() and unlinkat() for directory removal.  unlink() is the call that
> incorrectly removes the directories.  The pertinent bits are:
>
> 17500:  unlink("dir1")                                  = 0
> 17500:  unlink("dir2")                                  = 0
> 17500:  unlink("dirs")                                  = 0
> 17500:  unlink("/tmp/RtmpKrefN4/41c6167e")              = 0
> 17702:  lstat64("/", 0xFFBFF640)                        = 0
> 17702:  fstatat64(-3041965, "/tmp/RtmpKrefN4", 0xFFBFF5C8, 0x00001000) = 0
> 17702:  unlinkat(-3041965, "/tmp/RtmpKrefN4", 0x00000000) Err#1 EPERM
> [sys_linkd
> ir]
> 17702:  unlinkat(3, "file153e1776", 0x00000000)         = 0
> 17702:  unlinkat(3, "file47b5546c", 0x00000000)         = 0
> 17702:  unlinkat(3, "moredirs", 0x00000000)             Err#1 EPERM
> [sys_linkdir
> ]
> 17702:  fstatat64(3, "moredirs", 0xFFBFF530, 0x00001000) = 0
> 17702:  openat64(3, "moredirs", O_RDONLY|O_NONBLOCK|O_NOCTTY|O_NOFOLLOW) = 4
> 17702:  unlinkat(4, "somefile", 0x00000000)             = 0
> 17702:  unlinkat(3, "moredirs", 0x00000001)             = 0
> 17702:  unlinkat(-3041965, "/tmp/RtmpKrefN4", 0x00000001) Err#22 EINVAL
>
>
> I can provide the full truss output if desired.
>
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>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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