Merge branch 'master' of flubber:~hurd-web/hurd-web

4 files changed, 271 insertions, 2 deletions

diff --git a/open_issues/git-core-2.mdwn b/open_issues/git-core-2.mdwn
index 2cac56f2..2d8ad96b 100644
--- a/open_issues/git-core-2.mdwn
+++ b/open_issues/git-core-2.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2008, 2009, 2010 Free Software Foundation,
+[[!meta copyright="Copyright © 2008, 2009, 2010, 2011 Free Software Foundation,
 Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
@@ -13,6 +13,13 @@ License|/fdl]]."]]"""]]
 
 [[!tag open_issue_porting]]
 
+[[!toc]]
+
+
+# Log
+
+December, 2008.
+
 On the otherwise-idle flubber:
 
     $ git clone git://sources.redhat.com/git/glibc.git
@@ -98,3 +105,86 @@ differences to HEAD.
     fatal: cannot pread pack file: Interrupted system call
     fatal: index-pack failed
     error: Could not fetch savannah
+
+---
+
+2011-06-10, coulomb.SCHWINGE, checking out [[binutils]]' master branch,
+starting from an empty working directory (after an external `git push`):
+
+    $ git checkout -f
+    fatal: cannot create directory at 'gas/testsuite/gas/bfin': Interrupted system call
+    $ git checkout -f
+    error: unable to create file gas/testsuite/gas/i386/ilp32/x86-64-sse4_1-intel.d (File exists)
+    warning: unable to unlink gas/testsuite/gas/m68k-coff: Operation not permitted
+    fatal: cannot create directory at 'gas/testsuite/gas/m68k-coff': Operation not permitted
+    $ git checkout -f
+    error: unable to create file gas/testsuite/gas/h8300/h8300.exp (File exists)
+    error: unable to create file gas/testsuite/gas/i386/x86-64-addr32-intel.d (File exists)
+    error: unable to create file gas/testsuite/gas/ia64/secname.d (File exists)
+    error: unable to create file gas/testsuite/gas/m68k/pr11676.s (File exists)
+    Checking out files: 100% (12315/12315), done.
+    $ git status
+    # On branch master
+    # Changes not staged for commit:
+    #   (use "git add <file>..." to update what will be committed)
+    #   (use "git checkout -- <file>..." to discard changes in working directory)
+    #
+    #       modified:   gas/testsuite/gas/h8300/h8300.exp
+    #       modified:   gas/testsuite/gas/i386/x86-64-addr32-intel.d
+    #       modified:   gas/testsuite/gas/ia64/secname.d
+    #       modified:   gas/testsuite/gas/m68k/pr11676.s
+    #
+    no changes added to commit (use "git add" and/or "git commit -a")
+    $ rm gas/testsuite/gas/h8300/h8300.exp gas/testsuite/gas/i386/x86-64-addr32-intel.d gas/testsuite/gas/ia64/secname.d gas/testsuite/gas/m68k/pr11676.s
+    $ git checkout -f
+    $ git status
+    # On branch master
+    nothing to commit (working directory clean)
+
+
+# Analysis
+
+2011-06-13
+
+Running `git checkout -f` under GDB:
+
+    error: git checkout-index: unable to create file gas/testsuite/gas/cris/string-1.s (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/i386/x86-64-sse-check.d (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/i386/x86-64-sse4_1.d (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/ppc/astest.d (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/tic6x/reloc-bad-4.s (File exists)
+    warning: unable to unlink include/cgen: Operation not permitted
+    fatal: cannot create directory at 'include/cgen': Operation not permitted
+
+Again:
+
+    error: git checkout-index: unable to create file gas/config/te-vxworks.h (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/cris/string-1.s (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/d10v/warning-019.s (File exists)
+    error: git checkout-index: unable to create file gas/testsuite/gas/i860/dual03.s (File exists)
+    error: git checkout-index: unable to create file ld/testsuite/ld-mmix/sec-7a.s (File exists)
+    warning: unable to unlink ld/testsuite/ld-powerpc: Operation not permitted
+    fatal: cannot create directory at 'ld/testsuite/ld-powerpc': Operation not permitted
+
+And: [[git_duplicated_content]].
+
+All these (very likely) have the same root cause: `SA_RESTART` restarting too
+much.
+
+With `git checkout`, Git uses in progress.c a SIGALRM handler (`SA_RESTART`;
+invoked every second via `setitimer(ITIMER_REAL)`) to display status messages:
+*x % already checked out*.
+
+To avoid the status update signals every second, in
+`[git]/progress.c:start_progress_delay` we can just return `NULL` (manually in
+GDB, for example), then both the *error: git checkout-index* and the
+[[duplicated content|git_duplicated_content]] issues go away.
+
+I'm guessing that when returning from a `SA_RESTART` signal handler, too much
+of the \`\`syscall''s is being restarted.  For example, if a file has already
+been created, the restarted creation attempt would fail: *File exists*.  If
+data has been written, it might get written again (duplication issue). Then,
+there are cases where `unlink` apparently returns EINTR, which is not kosher
+either.  Etc.
+
+Do we have problems with `SA_RESTART` vs. the atomicity of our syscall-alikes?
diff --git a/open_issues/git_duplicated_content.mdwn b/open_issues/git_duplicated_content.mdwn
new file mode 100644
index 00000000..cbc171a7
--- /dev/null
+++ b/open_issues/git_duplicated_content.mdwn
@@ -0,0 +1,131 @@
+[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_porting]]
+
+    $ git-new-workdir ~/tmp/binutils/git /media/hd1s1/tmp/master master
+    error: unable to create file gas/testsuite/gas/arm/attr-mfpu-vfpv3-d16.d (Interrupted system call)
+    Checking out files: 100% (12315/12315), done.
+    Already on 'master'
+    $ cd /media/hd1s1/tmp/master
+    $ git status
+    # On branch master
+    # Changes not staged for commit:
+    #   (use "git add <file>..." to update what will be committed)
+    #   (use "git checkout -- <file>..." to discard changes in working directory)
+    #
+    #       modified:   gas/testsuite/gas/arm/attr-mfpu-vfpv3-d16.d
+    #
+    no changes added to commit (use "git add" and/or "git commit -a")
+    $ git checkout -f
+    $ git status
+    # On branch master
+    nothing to commit (working directory clean)
+
+([[Git issue|git-core-2]] is known.)
+
+    $ git-new-workdir ~/tmp/binutils/git /media/hd1s2/tmp/master master
+    error: unable to create file bfd/elf32-dlx.c (Interrupted system call)
+    error: unable to create file bfd/sunos.c (Interrupted system call)
+    error: unable to create file gas/testsuite/gas/arm/attr-mfpu-vfpv3-d16.d (Interrupted system call)
+    error: unable to create file gas/testsuite/gas/mmix/regx-op.d (Interrupted system call)
+    error: unable to create file gas/testsuite/gas/tic6x/reloc-bad-4.s (Interrupted system call)
+    error: unable to create file gold/testsuite/script_test_2.t (Interrupted system call)
+    error: unable to create file ld/testsuite/ld-mmix/loc7m.d (Interrupted system call)
+    error: unable to create file ld/testsuite/ld-powerpc/tlsexe.g (Interrupted system call)
+    Checking out files: 100% (12315/12315), done.
+    Already on 'master'
+    $ cd /media/hd1s2/tmp/master
+    $ git status
+    # On branch master
+    # Changes not staged for commit:
+    #   (use "git add <file>..." to update what will be committed)
+    #   (use "git checkout -- <file>..." to discard changes in working directory)
+    #
+    #       modified:   bfd/elf32-dlx.c
+    #       modified:   bfd/sunos.c
+    #       modified:   gas/testsuite/gas/arm/attr-mfpu-vfpv3-d16.d
+    #       modified:   gas/testsuite/gas/mmix/regx-op.d
+    #       modified:   gas/testsuite/gas/tic6x/reloc-bad-4.s
+    #       modified:   gold/testsuite/script_test_2.t
+    #       modified:   ld/testsuite/ld-mmix/loc7m.d
+    #       modified:   ld/testsuite/ld-powerpc/tlsexe.g
+    #
+    no changes added to commit (use "git add" and/or "git commit -a")
+    $ git checkout -f
+    $ git status
+    # On branch master
+    nothing to commit (working directory clean)
+
+Now you'd expect these directories to have identical content, but:
+
+    $ diff -x .git -ru /media/hd1s{1,2}/tmp/master/ > /tmp/diff
+    $ ls -l /tmp/diff
+    -rw-r--r-- 1 thomas thomas 613677 10. Jun 19:12 /tmp/diff
+    $ grep '^[^ @+-]' < /tmp/diff
+    diff -x .git -ru /media/hd1s1/tmp/master//ld/configure /media/hd1s2/tmp/master//ld/configure
+
+(Note that this isn't a file that Git had issues with.)
+
+Try again:
+
+    $ diff -x .git -ru /media/hd1s{1,2}/tmp/master/ > /tmp/diff_
+    $ ls -l /tmp/diff*
+    -rw-r--r-- 1 thomas thomas 613677 10. Jun 19:12 /tmp/diff
+    -rw-r--r-- 1 thomas thomas 613677 10. Jun 19:17 /tmp/diff_
+    $ cmp /tmp/diff{,_}; echo $?
+    0
+
+At least it's consistent.  Force a reload:
+
+    # settrans -ag /media/hd1s1
+    # settrans -ag /media/hd1s2
+
+Try again:
+
+    $ diff -x .git -ru /media/hd1s{1,2}/tmp/master/ > /tmp/diff__
+    $ ls -l /tmp/diff*
+    -rw-r--r-- 1 thomas thomas 613677 10. Jun 19:12 /tmp/diff
+    -rw-r--r-- 1 thomas thomas 613677 10. Jun 19:17 /tmp/diff_
+    -rw-r--r-- 1 thomas thomas 613677 10. Jun 19:30 /tmp/diff__
+    $ cmp /tmp/diff{,__}; echo $?
+    0
+
+Consistent; thus very likely corrupt on-disk.
+
+After a few tries, the pattern generally is that for the files where there are
+differences, once the file regularely ends, its content appears once more.
+That is, the files' content appears once (regularely), and then the same again.
+
+Some more copying:
+
+    $ (cd /media/hd1s1/tmp/ && cp -a master master_)
+    $ (cd /media/hd1s2/tmp/ && cp -a master master_)
+    $ diff -x .git -ru /media/hd1s1/tmp/master{,_}/ > /tmp/diff1
+    $ diff -x .git -ru /media/hd1s2/tmp/master{,_}/ > /tmp/diff2
+    $ ls -l /tmp/diff{1,2}
+    -rw-r--r-- 1 thomas thomas 0 10. Jun 19:46 /tmp/diff1
+    -rw-r--r-- 1 thomas thomas 0 10. Jun 19:46 /tmp/diff2
+
+No further difference.
+
+---
+
+    $ git-new-workdir git master master
+    $ diff -x .git -ur tar_master/ master/ > master.diff
+
+    $ rm -rf ar_master* && (cd git/ && git archive master) | (mkdir ar_master && cd ar_master/ && tar -x) && diff -x .git -ru tar_master/ ar_master/ > ar_master.diff; ls -l ar_master.diff
+    $ (cd git/ && git archive master) | md5sum
+
+---
+
+2011-06-13
+
+-> [[git-core-2]]
diff --git a/open_issues/git_nfs_mmap.mdwn b/open_issues/git_nfs_mmap.mdwn
new file mode 100644
index 00000000..b7e86491
--- /dev/null
+++ b/open_issues/git_nfs_mmap.mdwn
@@ -0,0 +1,48 @@
+[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_hurd open_issue_porting]]
+
+    $ git-new-workdir /media/kepler-data/home/thomas/tmp/source/binutils/git master master
+    fatal: Out of memory? mmap failed: No such device
+    $ echo $?
+    128
+    $ showtrans /media/kepler-data
+    /hurd/nfs kepler.schwinge.homeip.net:/media/data
+
+With `sh -x`:
+
+    [...]
+    + ln -s /media/kepler-data/home/thomas/tmp/source/binutils/git/.git/remotes master/.git/remotes
+    + ln -s /media/kepler-data/home/thomas/tmp/source/binutils/git/.git/rr-cache master/.git/rr-cache
+    + ln -s /media/kepler-data/home/thomas/tmp/source/binutils/git/.git/svn master/.git/svn
+    + cd master
+    + cp /media/kepler-data/home/thomas/tmp/source/binutils/git/.git/HEAD .git/HEAD
+    + git checkout -f master
+    fatal: Out of memory? mmap failed: No such device
+
+As one can easily guess (and confirm with [[hurd/debugging/rpctrace]]), `git`
+tries to [[glibc/mmap]] a file via the [[hurd/translator/nfs]] translator, this
+fails, and it isn't prepared to cope with that:
+
+    [...]
+      88->dir_lookup (".git/objects/pack/pack-37ca560e7877fa0cc6e5ddcd556aa73e5a3e3f40.idx" 2049 0) = 0 3 "/media/kepler-data/home/thomas/tmp/source/binutils/git/.git/objects/pack/pack-37"  (null)
+      62->dir_lookup ("media/kepler-data/home/thomas/tmp/source/binutils/git/.git/objects/pack/pack-37c" 2049 0) = 0 1 "/home/thomas/tmp/source/binutils/git/.git/objects/pack/pack-37ca560e7877fa0cc6e5"   61
+      61->dir_lookup ("home/thomas/tmp/source/binutils/git/.git/objects/pack/pack-37ca560e7877fa0cc6e5d" 2049 0) = 0 1 ""   84
+    task3741-> 3206 (pn{ 33}) = 0
+      84->term_getctty () = 0xfffffed1 ((ipc/mig) bad request message ID)
+      84->io_stat_request () = 0 {1 704 0 36308992 0 0 -1 33060 1 1000 1000 4712 0 1307711395 0 1307657003 0 1307657003 0 4096 16 0 1000 0 0 100663296 1836017780 29537 0 0 0 0}
+      84->io_map_request () = 0x4000002d (Operation not supported)
+      84->io_map_request () = 0x4000002d (Operation not supported)
+      76->io_write_request ("fatal: Out of memory? mmap failed: No such device
+    " -1) = 0 50
+      64->proc_mark_exit_request (32768 0) = 0
+    task3741-> 2008 () = 0
+    Child 3741 exited with 128
diff --git a/open_issues/nightly_builds.mdwn b/open_issues/nightly_builds.mdwn
index 5d1257fb..6eef7d19 100644
--- a/open_issues/nightly_builds.mdwn
+++ b/open_issues/nightly_builds.mdwn
@@ -20,7 +20,7 @@ Resources:
   * As reported in the [[news/2010-05-31]] news, there's Hydra doing nightly
     builds / Nix packages.
 
-  * <http://hudson-ci.org/>
+  * <http://hudson-ci.org/>, <http://jenkins-ci.org/>
 
   * <http://buildbot.net/>