Speaking at LCA 2009

Late notice (but that's all I got)... I'll be speaking at LCA 2009 in Hobart, Australia, on 22 Jan, considering what happens when kernel and userland don't talk.

Update: my presentation slides can be found here.

man-pages-3.17 is released

I've uploaded man-pages-3.17 into the release directory (or view the online pages). Notable changes in man-pages-3.17 are:

• A new endian(3) page documents functions added in glibc 2.9 that convert between host byte order and little- and big-endian order: htobe16(), htole16(), be16toh(), le16toh(), htobe32(), htole32(), be32toh(), le32toh(), htobe64(), htole64(), be64toh(), and le64toh().


• A new getifaddrs(3) page documents the getifaddrs() and freeifaddrs() library functions.


• 8 new pages describe various character sets: cp1251(7), iso-8859-10(7), iso_8859-13(7), iso_8859-14(7), iso_8859-3(7), iso_8859-5(7), iso_8859-8(7), and koi8-u(7). Thanks to Lefteris Dimitroulakis for contributing these!


• And various smaller changes in many other pages.

Tasmanian Devil

man-pages-3.16 is released

I've uploaded man-pages-3.16 into the release directory (or view the online pages). Notable changes in man-pages-3.16 are:

• A new pthread_getcpuclockid(3) page documents pthread_getcpuclockid().
• A new libc(7) page provides an overview of the standard C library implementations on Linux.
• A new rtld-audit(7) page provides an overview of the dynamic linker auditing API (modeled on the Solaris API): the functions la_version(), la_objsearch(), la_activity(), la_objopen(), la_objclose(), la_preinit(), la_symbind(), la_pltenter(), and la_pltexit().
  
• The ld.so(8) page adds documentation of the LD_AUDIT and LD_POINTER_GUARD environment variables.
  

See you at LCA 2009

It's too much fun to miss, so I finally made the booking... I'm going to LCA 2009 (19-24 Jan), in Hobart, Australia!

man-pages-3.15 is released

I've uploaded man-pages-3.15 into the release directory (or view the online pages). Notable changes in man-pages-3.15 are:

• A new makedev(3) page documents the makedev(), major(), and minor() macros used to manipulate device IDs.
• A new pthread_cleanup_push_defer_np(3) page documents pthread_cleanup_push_defer_np() and pthread_cleanup_pop_restore_np().
• The accept(2) page adds documentation of the new accept4() system call (coming in Linux 2.6.28)
• The fmemopen(3) page adds a description of open_wmemstream(3).
• The tcp(7) page adds a description of the use of the MSG_TRUNC flag for retrieving data from a TCP socket.
  
• Many updates to the atexit(3) page.
• Updates to many other pages
  

Special thanks to Petr Baudis for a lot of patches that went into this release.

Caballito del diablo ("Devil's little horse")

Linux Foundation fellowship, 6 months in

Not quite 6 months since I started the Linux Foundation fellowship, it's time to analyze and reflect on what has (or hasn't) been accomplished.

Some statistics

I took over maintainership of man-pages at the start of November 2004, with the first release being man-pages-2.00. From then until the fellowship started in the middle of May this year (a period of 185 weeks), I probably spent between 0 and 2.5 days a week on man-pages, most of it done as private, volunteer work. (For a period of around a year, I probably managed up about half day a week as part of my day job; thanks Google!) I'd guess it was a bit better than day a week on average (let's say 1.25 days), and we could roughly estimate that as the equivalent of 45 working weeks.

Since the fellowship started, I've worked for about 25 weeks on man-pages; that is, somewhat more than half of the estimated time that I spent on man-pages in the preceding 3.5 years. The first release during my tenure of the fellowship was man-pages-2.80, and since then there have been 15 more (man-pages-3.00 through man-pages-3.14).

What I'm expecting is that the limiting factor in the progress of man-pages is the availability of my time. If I get to work at around four times the rate I did before, then we should see a corresponding increase in the progress of man-pages. Very roughly, in the last 6 months, progress should have been somewhat more than 50% of what it was in the previous 3.5 years.So here's a first comparison:

Period	Number of releases
Pre-fellowship	80
During fellowship	16

Well, that doesn't look so good. But there's no question that there's more work going on for each release nowadays. Here's another simple statistic, derived from the commit logs:

Period	Number of commits
Pre-fellowship	3610
During fellowship	1852

Commits in the last 6 months were nearly 50% of the total during the previous 3.5 years. That seems roughly in line with expectations, and supports the theory that there's a lot more work going into each man-pages release nowadays. Of course, commits vary a lot in size, ranging from a spelling fix, to a complete new page, and going through to some of the enormous global formatting fixes that took place in the man-pages-2.* series, so this is a very rough measure. (One of the commits cleaning up source files layout in man-pages-2.47 had a diff size of more than 60000 lines(!). There were many other large formatting commits in the man-pages-2.*, which is why trying to compare the volume of diffs before and during the fellowship doesn't produce a useful metric.)Another rough measure is how many man pages were added to the set over time:

Period	Number of new pages added
Pre-fellowship	93
During fellowship	56

Again, that's roughly in line with expectations, with the number of pages added during the fellowship being somewhat more than 50% of the previous period.

But where did the new pages come from?

Period	By mtk	By others	By mtk + other(s)	Imports
Pre-fellowship	52	22	13	6
During fellowship	50	4	1	1

"mtk" is me. "Other(s)" is someone else. "Imports" are pages under a free license that I scooped up from some other source (e.g., found on the net, in a distro, or in BSD).

On the negative side, I wrote the vast majority of new pages that have been added so far during the fellowship. On the positive side, Paul Jackson contributed the single biggest page, cpuset(7), which became the fourth largest page in man-pages. (Also worth noting: in the man-pages-2.* releases, a total of 28 pages were deleted, mainly obsolete pages in Section 1.) In fact, I had hoped to be able to get even more pages written, but other tasks, such as testing, API review, and kernel patches have also taken up a significant fraction of my time during the fellowship. When considered as a (calendar) monthly rate, contributions of new pages by others are, unfortunately, essentially unchanged since before the fellowship.

So, progress towards improving contributions by others, at least in terms of new pages, has not been good. However, my gut feeling has been that more people are actually contributing to man-pages than before: the fact that there is a full-time maintainer means people are rather more likely to send bug reports, suggestions, and patches for existing pages. Here's a statistic that bears it out:

Period	Average contributors/week
Pre-fellowship	2.8
During fellowship	5.9

This was calculated by summing the number of contributors in each of the change logs in all of the releases over the two periods and then dividing by the number of calendar weeks in each period (185 and 28 respectively). 5.9 contributors per week is still much lower than I'd like, but my feeling is that the rate has increased steadily over the time of the fellowship, so that the current rate is already higher than 5.9, and set to increase further. (Another factor that may also have helped boost the number of reports is that in December 2007 I started adding a COLOPHON to each man page describing how to report bugs, and this change would have filtered into distribution CDs a few months later.)

Timeliness of documentation

Things have defintely got better during the fellowship. Most additions and changes to the kernel-userland interface during the time of the fellowship have been documented in man-pages pretty much as they occur. (This contrasts with earlier times, where interface changes have sometimes been followed only months (or in extreme cases years) later by man page updates.) Most notably, Ulrich Drepper's new system calls in Linux 2.6.27 saw man pages go out a few days after the release of that kernel.

Testing and bug reporting

I've done a fair bit of this over the course of the fellowship. Most new system calls and system call extensions got tested by me before they hit mainline. This uncovered a few bugs which were then fixed. The biggest single piece of work here was for the utimensat(2) system call, producing a test suite (later integrated into LTP), along with patches that fixed the 5 or so bugs in the interface (details here).

Many existing glibc functions also got tested as I updated the man pages for them. Most notably, updates to the man pages produced about 35 bug reports related to error reporting by the math functions. The addition of man pages for various pthreads functions has also been accompanied by a lot of testing, and a half dozen or so bug reports.

API design review

Most new system calls and system call extensions got reviewed before going into mainline. (My record on other kernel interfaces, such as /proc files, was a more spotty though.) Among other things, this resulted in a redesign of the proposed extension of the accept() system call (originally proposed as paccept(), with a signal set argument whose necessity was dubious, later revised to accept4(), which should appear in kernel 2.6.28).

Miscellaneous

A summary of other man-pages work that I've done during the time of the fellowship:

• man-pages moved from a private Subversion repository to a public git repository on kernel.org.

• In general, I'm blogging a bit more actively nowadays, and in addition to posts summarizing releases, there have been longer posts on topics such as: problems with kernel-userland interface design and implementation; the state of error reporting for glibc's math functions; and a few articles describing or summarizing Linux kernel-userland interface changes.

• After my presentation at LPC for the kernel-userland interface track, I finally got round to an idea I'd been considering for a while: creating the linux-api mailing list. The rationale for the list is that all patches that cause API/ABI changes should be CCed to the list, so that the many parties who are interested in API/ABI changes (e.g., man-pages, LSB, libc developers, kernel developers, testers such as the folk at LTP, and of course userland developers) can get an idea of what's going on. Most people still don't read Documentation/SubmitChecklist, to know they should be using this list, so I try to regularly chase people to use it (and some others also help in that regard), and by now at least some people do so without prompting.

• I've helped out LSB on a number of occasions, filing a few bug reports against the spec, but also helping out by writing man pages for functions that they wanted to specify that were currently undocumented (see, e.g., here and here). This resulted in new man pages such as getprotoent_r(3), getservent_r(3), getnetent_r(3), and pthread_getattr_np().
  

• I continue to respond to many bug reports in the manpages and manpages-dev components of Debian's bug tracking system. This has mutual benefits: on the one hand, although I'm not actually a member of Debian, I'm by far the most active fixer of their bug reports; on the other hand, most Debian bug reports for man pages really apply to the upstream pages (I ignore the ones that don't), and so the reports provide a valuable source of pointers to things that need fixing in man-pages. A big thank you to Debian users, who produce far more (and more useful) man-pages bug reports than all of the other distributions put together!

• Working on man-pages led me to find various deficiencies in POSIX.1 specifications, resulting in around a half dozen bug reports to the Austin group.

Mariposa

Publish Post

man-pages-3.14 is released

I've uploaded man-pages-3.14 into the release directory (or view the online pages). Notable changes in man-pages-3.14 are:

• A new CPU_SET(3) page documents the CPU_* macros used for manipulating CPU sets (the cpu_set_t data structure used by sched_setaffinity(2), pthread_attr_setaffinity_np(3), and pthread_setaffinity_np(3)).
• More man pages for POSIX threads library functions: 5 new pages documenting 8 functions
• pthread_attr_setinheritsched(3) (includes documentation of pthread_attr_getinheritsched())
• pthread_cancel(3)
• pthread_cleanup_push(3) (includes documentation of pthread_cleanup_pop())
• pthread_setcancelstate(3) (includes documentation of pthread_setcanceltype())
• pthread_testcancel(3)
  
• clone(2) adds documentation of the CLONE_NEWNET, CLONE_NEWUTS, CLONE_NEWPID, and CLONE_IPC flags.
• mmap(2) adds documentation of the MAP_STACK flag.
• arp(7) adds documentation of a few preously undocumented /proc files.
• icmp(7) adds documentation of a few previously undocumented /proc files.
• tcp(7) adds documentation of many previously undocumented /proc files.
• udp(7) adds documentation of a few previously undocumented /proc files.
• pthreads(7) adds lists of functions that POSIX.1 specifies are and may be cancellation points.

Lagarto

man-pages-3.13 is released

I've uploaded man-pages-3.13 into the release directory (or view the online pages). Notable changes in man-pages-3.13 are:

• More man pages for POSIX threads library functions: 6 new pages documenting 11 functions.
  
  • pthread_attr_setaffinity_np(3) (includes documentation of pthread_attr_getaffinity_np(3))
    
  • pthread_attr_setschedparam(3) (includes documentation of pthread_attr_getschedparam(3))
  • pthread_attr_setschedpolicy(3) (includes documentation of pthread_attr_getschedpolicy(3))
  • pthread_setaffinity_np(3) (includes documentation of pthread_getaffinity_np(3))
  • pthread_setschedparam(3) (includes documentation of pthread_getschedparam(3))
  • pthread_setschedprio(3)
• Various fixes and improvements to the example program in epoll(7).

Saltamontes, intentando evitarme

Recent changes in file descriptor system calls

In recent Linux kernels, especially 2.6.27, a number of system calls have changed, or new versions of existing system calls have been added, to allow more control over the file descriptors created by those system calls. (Most of this work has been done by Ulrich Drepper.) These changes have taken the form of either adding new bits to the flags bit-mask argument of an existing system call, if it had such an argument, or creating a new version of the system call that adds an extra flags argument. In most cases, two new flags have been added: a close-on-exec flag, and a non-blocking flag, which we describe shortly.

The changes are summarized in the table below. In this table, the Kernel column indicates the kernel version where the change occurred, and the Glibc column indicates the version of glibc that adds the corresponding wrapper functions and/or header file definitions. (Note: glibc 2.9 is not yet released.)

Interface	Changes	Kernel	Glibc	Notes
open(2)	New flag: O_CLOEXEC	2.6.23	2.7	Flag also supported for openat(2). These syscalls already supported O_NONBLOCK.
fcntl(2)	New flag: F_DUPFD_CLOEXEC	2.6.24	2.7	Performs a similar task to dup3(2)
recvmsg(2)	New flag: MSG_CMSG_CLOEXEC	2.6.23	2.7	-
dup3(2)	New syscall, like dup2(2), but adds flags argument (O_CLOEXEC)	2.6.27	2.9	Requires new glibc interface
pipe2(2)	New syscall, like pipe(2), but adds flags argument: O_CLOEXEC, O_NONBLOCK	2.6.27	2.9	Requires new glibc interface
socket(2)	New flags in type argument: SOCK_CLOEXEC, SOCK_NONBLOCK	2.6.27	2.9	-
socketpair(2)	New flags in type argument: SOCK_CLOEXEC, SOCK_NONBLOCK	2.6.27	2.9	-
epoll_create1(2)	New syscall, like epoll_create(2), but adds flags argument: EPOLL_CLOEXEC; the new system call drops epoll_create()'s obsolete size argument	2.6.27	2.9	Requires new glibc interface
inotify_init1(2)	New syscall, like inotify_init(2), but adds flags argument: IN_CLOEXEC, IN_NONBLOCK	2.6.27	2.9	Requires new glibc interface
eventfd2(2)	New syscall, like eventfd(2), but adds flags argument: EFD_CLOEXEC, EFD_NONBLOCK	2.6.27	2.9	The glibc eventfd() wrapper already allowed a flags argument, so no new wrapper is required
signalfd4(2)	New syscall, like signalfd(2), but adds flags argument: SFD_CLOEXEC, SFD_NONBLOCK	2.6.27	2.9	The glibc signalfd() wrapper already allowed a flags argument, so no new wrapper is required
timerfd_create(2)	New flags: TFD_CLOEXEC, TFD_NONBLOCK	2.6.27	2.9	-

A proposed analogous change for accept(2), paccept(), supporting flags SOCK_CLOEXEC and SOCK_NONBLOCK and treatment of a signal mask argument like pselect(2), was debated and then spent some time in limbo, but has recently re-emerged in a somewhat modified form, accept4() (which was in fact the original proposal), that will probably go into Linux 2.6.28 or 2.6.29.

Perhaps one day there might even be an analogous change for mq_notify(3), since (on Linux, but not on most other systems) a message queue descriptor is really just a file descriptor.

The close-on-exec flag (*_CLOEXEC)

The addition of a close-on-exec flag was the primary motivator for the system call changes. Specifying this flag causes the file descriptor created by the system call to automatically have its close-on-exec flag set. (This flag causes the file descriptor to automatically be closed if the process does a successful execve(2).)

Before the existence of this flag, it was possible to change the close-on-exec flag of a file descriptor after it has been created, using the fcntl(2) F_GETFL and F_SETFL operations. The fact that this required two additional system calls was not so problematic as the fact that the need for multiple (non-atomic) steps to set the flag on a new file descriptor meant that there were certain race conditions that could lead to races in multithreaded programs where one thread was trying to set a file descriptor's close-on-exec flag at the same time as another thread was performing a fork() plus execve(). Ulrich Drepper explains the resulting security issues in more detail.

The non-blocking flag (*_NONBLOCK)

The *_NONBLOCK flag causes the non-blocking flag to be set on the open file description associated with the new file descriptor. (For a discussion of the relationship of a file descriptor to an open file description, see the open(2) man page.)

Unlike the *_CLOEXEC flag, the *_NONBLOCK flag exists merely as a convenience: it saves two system call operations (fcntl(2) F_GETFL and F_SETFL) if we want to immediately set the non-blocking flag when opening a file descriptor.

Note that there deliberately is no *_NONBLOCK flag for dup3(2). This would not be sensible, since the new file descriptor shares an open file description with the old file descriptor.

There is also deliberately no *_NONBLOCK flag for epoll_create1(2), since equivalent functionality can be obtained with a zero timeout.

Other flags?

The flags argument added for the new system calls allows for other kinds of functionality to be added to these system calls in the future.

Future standards?

Ulrich Drepper already did some work on getting some of these interface changes into the POSIX.1-2008 standard, which includes specifications of the O_CLOEXEC flag for open() and the F_DUPFD_CLOEXEC operation for fcntl(). In the future, some the other changes may also make their way into the standard.

A note on the new system call names

The numbers in the names of the new system calls refer to the number of arguments that each system call has. This is an extension of a convention that was used for some existing Unix system calls, notably dup2(2), wait3(2), and wait4(2). Note that while the wrapper function for signalfd(2) has three arguments, the underlying signalfd4() system call really does have four arguments, as described in the man page. (However, this suggests that, in the end, this naming scheme might not have been the best choice.)

man-pages-3.12 is released

I've uploaded man-pages-3.12 into the release directory (or view the online pages). Notable changes in man-pages-3.12 are:

• Documentation is added for a set of new and changed system calls (which will be the subject of a future post) that extend the functionality of existing system calls that work with file descriptors. (The changes occurred in kernel 2.6.27.) The new and modified system calls add flags that allow the close-on-exec file descriptor flag to be set, and the non-blocking file status to be set on a file description, as the file is opened. The modified pages are:
• dup(2) adds a description of the new dup3() system call.
• epoll_create(2) adds a description of the new epoll_create1() system call.
• eventfd(2) adds a description of the new eventfd2() system call.
• inotify_init(2) adds a description of the new inotify_init1() system call.
• pipe(2) adds a description of the new pipe2() system call.
• signalfd(2) adds a description of the new signalfd4() system call.
• socket(2) and socketpair(2) add a description of the new SOCK_CLOEXEC and SOCK_NONBLOCK flags.
• timerfd_create(2) adds a description of the new TFD_CLOEXEC and TFD_NONBLOCK flags.
• A start has been made on providing man pages for the POSIX threads library functions: 15 new pages documenting 23 functions.
  
  • pthread_attr_init(3) (includes documentation of pthread_attr_destroy(3))
  • pthread_attr_setdetachstate(3) (includes documentation of pthread_attr_getdetachstate(3))
  • pthread_attr_setguardsize(3) (includes documentation of pthread_attr_getguardsize(3))
  • pthread_attr_setscope(3) (includes documentation of pthread_attr_getscope(3))
  • pthread_attr_setstacki(3) (includes documentation of pthread_attr_getstack(3))
  • pthread_attr_setstackaddr(3) (includes documentation of pthread_attr_getstackaddr(3))
  • pthread_attr_setstacksize(3) (includes documentation of pthread_attr_getstacksize(3))
  • pthread_create(3)
  • pthread_detach(3)
  • pthread_equal(3)
  • pthread_exit(3)
  • pthread_getattr_np(3)
  • pthread_join(3)
  • pthread_self(3)
  • pthread_tryjoin_np(3) (includes documentation of pthread_timedjoin_np(3))
• Many details were added to, or fixed in, ld.so(8).

El jardín de la casa

man-pages-3.11 is released

I've uploaded man-pages-3.11 into the release directory (or view the online pages). Notable changes in man-pages-3.11 are:

• A new umount(2) page has been created by splitting the umount() and umount2() material out of the old mount(2) page.
• The mount(2) page adds a description of per-process namespaces.
• Various fixes and improvements in getdents(2), including the addition of an example program.
• Many improvements and additions in signal(7), the page that provides an overview of signals on Linux.
• Numerous fixes to many other pages.
  

man-pages-3.10 is released

I've uploaded man-pages-3.10 into the release directory (or view the online pages). This is a fairly light release; conferences, and learning and changing my workflow for git have take a bit of time lately. Notable changes in man-pages-3.10 are:

• The clone(2) and getpid(2) pages add some notes and details of the consequences of the PID caching performed by glibc's getpid() wrapper function.
• Various changes to services(5), including removing various out-of-date pieces of text.
  

git update

I updated my previous post, mainly to add the details required to import subversion tags into git. If you cloned the repository that I put up at kernel.org about a week ago, you'll need to re-clone. (Sorry!)

The timing has been good. Primed and ready to start learning more about git, I got to join a sizable crowd at the Linux Plumbers Conference to see Linus giving a highly informative and entertaining tutorial on git.

man-pages goes git (at last!)

[Update: 19 Sep 2008: when I first attempted the git import, I didn't import the subversion tags into git. I've updated and expanded this post to include the required details to do that.]

When I inherited man-pages, there was no version control system (VCS) in use. To help myself keep track of changes, I've been running a private subversion repository since I took over as maintainer (i.e., since man-pages-2.00), but I never got round to hosting it on a public server so that people could pull from it (requests for such a facility were only occasional). Instead, people wanting to send patches would just grab the latest tarball from the downloads directory, patch the required source file, and email me the patch.

Somewhat more frequent requests for a public repository, and the fact that the Linux world is nowadays mostly oriented around the git distributed version control system, have gradually created a pressure to change things. So, I'm taking baby steps towards using git for man-pages. Here goes...

Importing from subversion to git

I found the Simplistic Complexity blog's simple instructions on subversion-to-git migration quite useful (though it didn't supply all of the details I needed for importing subversion tags).

My subversion repository had a somewhat non-standard layout, which affected the options (see the git svn init command below) that I needed to do an import that included my subversion tags. (Thanks to various people on the git mailing list who helped me find the right way to do things, especially Björn Steinbrink and Michael Gruber.) The following subversion commands give an idea of the layout:

$ svn list file:///home/mtk/man-pages-rep
branches/
tags/
trunk/
$ svn list file:///home/mtk/man-pages-rep/trunk
man-pages/
$ svn list file:///home/mtk/man-pages-rep/trunk/man-pages
Changes
Changes.old
Makefile
README
...
man7/
man8/
scripts/
$ svn list file:///home/mtk/man-pages-rep/tags
man-pages-2.00/
man-pages-2.01/
...
man-pages-3.08/
man-pages-3.09/
$ svn list file:///home/mtk/man-pages-rep/tags
man-pages-2.00
man-pages-2.01
...
man-pages-3.08
man-pages-3.09
$ svn list file:///home/mtk/man-pages-rep/tags/man-pages-2.00
man-pages
$ svn list file:///home/mtk/man-pages-rep/tags/man-pages-2.01
man-pages
[and so on]
$ svn list file:///home/mtk/man-pages-rep/branches
$
[i.e., no branches, since this has been a linear svn repo.]

Set up an empty, temporary git repository, in the process informing git about the location of the subversion repository from which the import should be done:

$ cd $HOME
$ mkdir man-pages-git-tmp
$ cd man-pages-git-tmp
$ git svn init file:///home/mtk/man-pages-rep/ \
                    -T trunk/man-pages \
                    -b branches/*/man-pages
                    -t tags/*/man-pages
                    --no-metadata
Initialized empty Git repository in .git/

Tell git about the names of users in the subversion commit logs. Because the subversion repository was private (I just took other people's emailed input and made changes as required), I'm the only user. That means that the historical information in the repository will be bogus, suggesting that I'm responsible for all of the nearly 5000 commits to the repository, when it's probably more like 75%. My apologies to everyone else. Something like the true story for man-pages 2.00 through to 3.09 can be found here.

$ cat > ~/users.txt
mtk = Michael Kerrisk
^D
$ git config svn.authorsfile ~/users.txt

Do the import:

$ time git svn fetch
[...]
        M Changes
r4917 = 93a6e8f9ee5d0710a084425548775348389e2900 (git-svn)
Checking out files: 100% (1925/1925), done.
Checked out HEAD:
  file:///home/mtk/man-pages-rep/trunk/man-pages r4917

real 70m24.850s
user 14m46.571s
sys 22m29.852s

And yes, I definitely need some faster hardware...

At this point, git branch -a showed that I had imported the subversion tags into git. But the tags still need to be turned into proper git tags. This requires a command for each tag, which can be automated in a script. (Thanks to Heikki Orsila who pointed out to me that this step was required, and who supplied the script.)

$ cat git-svn-tags.sh
#!/bin/sh
#
git branch -a | grep tags/ | while read tag ; do
  tagname=$(echo $tag | cut -d/ -f2)
  commit=$(git rev-parse $tag)
  res=$(git log master | grep "^commit $commit")
  if test -z "$res" ; then
      # take the parent commit for the tag commit (found in master)
      commit=$(git rev-parse $tag^)
  fi
  echo $tagname $commit
  git tag -a $tagname $commit -m "This is $tagname"
done

$ sh ~/git-svn-tags.sh
man-pages-2.00 105a35bc69bd3088d69f5d3c94d22e6595e223d2
man-pages-2.01 972a9aee950d4df97cc1f81147b64fe52007dfc7
...
man-pages-3.08 5c8cbdc1b2c9b5a1ebb8626361ea01cb73965636
man-pages-3.09 81468e1308f643ffd5718809379c074ff75dc311
$ git tag -l
man-pages-2.00
man-pages-2.01
...
man-pages-3.08
man-pages-3.09

Clone the temporary repository, to produce a clean repository from which any lingering cruft that was used to support git svn has been removed:

$ git clone man-pages-git-tmp man-pages-git
Initialized empty Git repository in /home/mtk/man-pages-git/.git/
0 blocks

And then run a garbage collection to clean up any remaining unneeded files, and otherwise improve the efficiency of the repository:

$ git gc
Counting objects: 36341, done.
Compressing objects: 100% (12059/12059), done.
Writing objects: 100% (36341/36341), done.
Total 36341 (delta 29117), reused 29623 (delta 23595)

Hosting the git repository on kernel.org

The public git repository is to be hosted on kernel.org. Quite a while back the admins there already set up a location for a man-pages git repository. Jeremy Kerr kindly held my hand through the hurdles of the initial set up.

On kernel.org, the admins assigned man-pages a repository location of /pub/scm/docs/man-pages. So, let's create an empty repository there:

$ ssh mtk@master.kernel.org
mtk@master.kernel.org's password:
[mtk@hera man-pages]$ cd /pub/scm/docs/man-pages
[mtk@hera man-pages]$ git init
[mtk@hera man-pages]$ mv .git/ man-pages.git
[mtk@hera man-pages]$ exit

Back on my local machine, modify the git repository's config file so that I can write simple git push commands to push changes onto the kernel.org repository

$ cat >> ~/man-pages-git/.git/config
[remote "kernel.org"]
        url = ssh://master.kernel.org/pub/scm/docs/man-pages/man-pages.git
        push = +refs/heads/master:refs/heads/master

And then do the push to kernel.org:

$ cd $HOME/man-pages-git
$ git push kernel.org
mtk@master.kernel.org's password:
Counting objects: 36341, done.
Compressing objects: 100% (12059/12059), done.
Writing objects: 100% (36341/36341), 8.62 MiB 681 KiB/s, done.
Total 36341 (delta 29117), reused 29623 (delta 23595)
To ssh://master.kernel.org/pub/scm/docs/man-pages/man-pages.git
 * [new branch] master -> master

Log into kernel.org and give the repository a public description:

$ ssh mtk@master.kernel.org
mtk@master.kernel.org's password:
[mtk@hera man-pages]$ cat > /pub/scm/docs/man-pages/man-pages.git/description
Man pages for Linux kernel and glibc APIs
^D
[mtk@hera man-pages]$ exit

And then we have the repository visible and ready for use at http://git.kernel.org/, and you can clone it using the following command:

$ git clone git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git

PS In case it's not clear: only use git to submit changes to man-pages if that's your preference. It's still possible to submit patches the good old-fashioned way, by grabbing the latest release (tarballs will continue to be released as usual every week or two), editing the required source file(s), and sending me a diff -u patch by email.

man-pages-3.09 is released

I've uploaded man-pages-3.09 into the release directory (or view the online pages). Notable changes in man-pages-3.09 are:

• A new fopencookie(3) page, documents a library function that allows a custom implementation of a stdio stream.
• A new networks(5) page (adopted from Debian) documents the /etc/networks file.
• Feature test macro requirements were added or fixed for various pages.
• Many parts of the hsearch(3) man page were fixed and rewritten.

Dan Jacobson remarked that people who read the COLOPHON at the end of each man page may have a kernel or glibc bug to report, rather than a man-pages bug report, but that following the URL in the COLOPHON only leads to a page describing how to report documentation bugs. So, I wrote a new page giving some pointers about reporting kernel and glibc bugs, and that page is linked from the man-pages reporting bugs page.

Fast fertig auf da Wiesn