I run builds on my laptop, but it also crashes about 1/4 of the time
while suspending. It's definitely undesrirable to get e.g. empty
.dirtree objects because they corrupt builds. Concretely, I was
getting empty contents committed for xorg-util-macros.
Now, we used to write out temporary files using g_file_replace() which
does a fsync() during close, but then switched to a more "manual"
g_file_append_to().
We could switch back to g_file_replace(), but the problem is, we don't
want to call fsync() on temporary files in the case where we already
have the object. Attempting to add an object we already have is a
*very* common case.
This is both the old and new code sequence for the case where an
object is already stored:
open(temp, O_WRONLY)
write() write() write()
close()
lstat(objects/3a/9fe332...) = 0
unlink(temp)
In the *new* code, here's the case where an object *isn't* stored:
open(temp, O_WRONLY)
write() write() write()
close()
lstat(objects/3a/9fe332...) = -1
open(temp, O_RDONLY)
fdatasync()
close()
rename(temp, objects/3a/9fe332)
Compare with the *old* code path for when an object isn't stored:
open(temp, O_WRONLY)
write() write() write()
close()
lstat(objects/3a/9fe332...) = -1
link(temp, objects/3a/9fe332)
unlink(temp)
The problem with this is we really need to fdatasync(). Also doing
just rename() instead of the weird link()/unlink() helps us express to
the filesystem that we want atomic semantics. For example, BTRFS has
special handling for rename().
We really don't have a sane story for private files. This is a
defensive step ensuring that with old versions of gnome-ostree,
components that mistakenly have un-world-readable files don't break
pulls.
The qemu helper really wants to copy kernel modules, but not
update the system bootloader. Allow it to reuse ostadmin for
this.
Note that our previous path of shelling out to "cp -al" broke because
it refused to make cross-device links.
# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# On branch master
# Your branch is ahead of 'origin/master' by 1 commit.
#
# Changes to be committed:
# (use "git reset HEAD <file>..." to unstage)
#
# modified: src/libotutil/ot-gio-utils.c
# modified: src/libotutil/ot-gio-utils.h
# modified: src/ostadmin/ot-admin-builtin-deploy.c
#
# Untracked files:
# (use "git add <file>..." to include in what will be committed)
#
# embedded-dependencies/glib/
# embedded-dependencies/libsoup/
The old command line syntax assumed you wanted the latest from
a given revision, but to bisect, you really want the ability
to deploy any given one.
Old:
$ ostadmin deploy gnomeos-3.6-i686-{runtime,devel}
New:
$ ostadmin deploy trees/gnomeos-3.6-i686-runtime
$ ostadmin deploy trees/gnomeos-3.6-i686-devel
And note that the deploy directory now changes to:
/ostree/trees/gnomeos-3.6-i686-devel
And now it's possible to:
$ ostadmin deploy trees/gnomeos-3.6-i686-devel trees/gnomeos-3.6-i686-devel^^^
This helps make things less confusing when we try to create a file not
owned by our uid, such as running ostree-pull as non-root on a
repository owned by root.
The "status text" code was assuming that libsoup was only doing one
thing at a time, but that's never been the case. Change the code to
display the status of all active requests.
This can be a large performance win in certain circumstances:
* Cold buffer cache (we don't block the whole process)
* Requiring a copy instead of hardlink
The previous fix to just ignore symbolic links for hard linking isn't
really good enough, since it can happen for empty files too.
Since this is an optimization, when we get EMLINK, let's instead just
fall back to copying. This also applies to EXDEV.
Rather than always doing:
1) make temporary link
2) unlink() target
3) rename()
Just try making the link, and only do the second two if the file
already exists. This reduces system call traffic a lot.
We should explicitly distinguish between the case where we have a git
branch we're following, versus an immutable tag. In the latter case,
we can entirely avoid running 'git fetch' for it once we have it.
This is a noticeable speedup in our current scenario of pinning WebKit
to a tag.
The git mirroring code now has a --fetch-skip-secs=X option which
allows us to basically run it in a loop, without hitting remote git
repositories too often.
This is the new workflow:
$ ostbuild import-tree wip-gnome-menus-3.6
$ $EDITOR ~/build/ostbuild/snapshots/wip-gnome-menus-3.6-2012.1-abcd.json
$ ostbuild build
Colin Walters