Commit graph

162 commits

Author SHA1 Message Date
Eelco Dolstra
2001895f3d Add a --repair flag to ‘nix-store -r’ to repair derivation outputs
With this flag, if any valid derivation output is missing or corrupt,
it will be recreated by using a substitute if available, or by
rebuilding the derivation.  The latter may use hash rewriting if
chroots are not available.
2012-10-02 17:13:46 -04:00
Eelco Dolstra
8e3a7bd712 nix-store --verify: Add an option ‘--repair’ to repair all missing/corrupt paths
Also, return a non-zero exit code if errors remain after
verifying/repairing.
2012-10-02 15:12:56 -04:00
Eelco Dolstra
d534f137f0 Make the store writable before creating /nix/store/.links 2012-09-25 16:30:08 -04:00
Eelco Dolstra
b9c2b4d5b4 Remove setting of the immutable bit
Using the immutable bit is problematic, especially in conjunction with
store optimisation.  For instance, if the garbage collector deletes a
file, it has to clear its immutable bit, but if the file has
additional hard links, we can't set the bit afterwards because we
don't know the remaining paths.

So now that we support having the entire Nix store as a read-only
mount, we may as well drop the immutable bit.  Unfortunately, we have
to keep the code to clear the immutable bit for backwards
compatibility.
2012-09-19 16:17:54 -04:00
Eelco Dolstra
b9124a5c33 Support having /nix/store as a read-only bind mount
It turns out that the immutable bit doesn't work all that well.  A
better way is to make the entire Nix store a read-only bind mount,
i.e. by doing

  $ mount --bind /nix/store /nix/store
  $ mount -o remount,ro,bind /nix/store

(This would typically done in an early boot script, before anything
from /nix/store is used.)

Since Nix needs to be able to write to the Nix store, it now detects
if /nix/store is a read-only bind mount and then makes it writable in
a private mount namespace.
2012-09-19 15:45:29 -04:00
Eelco Dolstra
76e88871b2 Templatise tokenizeString() 2012-09-19 15:43:23 -04:00
Eelco Dolstra
e6e495649c Vacuum the SQLite DB after running the garbage collector 2012-09-13 14:33:41 -04:00
Eelco Dolstra
c770a2422a Report substituter errors to clients of the Nix daemon 2012-08-01 11:19:24 -04:00
Eelco Dolstra
97421eb5ec Refactor settings processing
Put all Nix configuration flags in a Settings object.
2012-07-30 19:55:41 -04:00
Eelco Dolstra
d059bf48e4 Pass configuration settings to the substituters
Previously substituters could read nix.conf themselves, but this
didn't take --option flags into account.
2012-07-30 16:09:54 -04:00
Eelco Dolstra
f9613da180 Remove unused variables 2012-07-30 15:43:37 -04:00
Eelco Dolstra
6183cf2f19 Fix whitespace 2012-07-30 15:42:18 -04:00
Eelco Dolstra
50395b71a9 Fix the substituter tests 2012-07-26 17:36:07 -04:00
Eelco Dolstra
8c79100839 Merge branch 'master' into no-manifests 2012-07-26 15:14:33 -04:00
Eelco Dolstra
6193105710 Automatically optimise the Nix store when a new path is added
Auto-optimisation is enabled by default.  It can be turned off by
setting auto-optimise-store to false in nix.conf.
2012-07-23 17:14:15 -04:00
Eelco Dolstra
6852289c46 Use lutimes() if available to canonicalise the timestamp of symlinks
Also use utimes() instead of utime() if lutimes() is not available.
2012-07-23 16:52:25 -04:00
Eelco Dolstra
fe241ece29 Merge branch 'master' into no-manifests 2012-07-18 10:47:59 -04:00
Eelco Dolstra
ccc52adfb2 Add function queryPathFromHashPart()
To implement binary caches efficiently, Hydra needs to be able to map
the hash part of a store path (e.g. "gbg...zr7") to the full store
path (e.g. "/nix/store/gbg...kzr7-subversion-1.7.5").  (The binary
cache mechanism uses hash parts as a key for looking up store paths to
ensure privacy.)  However, doing a search in the Nix store for
/nix/store/<hash>* is expensive since it requires reading the entire
directory.  queryPathFromHashPart() prevents this by doing a cheap
database lookup.
2012-07-17 18:55:39 -04:00
Eelco Dolstra
09a6321aeb Replace hasSubstitutes() with querySubstitutablePaths()
querySubstitutablePaths() takes a set of paths, so this greatly
reduces daemon <-> client latency.
2012-07-11 17:52:18 -04:00
Eelco Dolstra
58ef4d9a95 Add a function queryValidPaths()
queryValidPaths() combines multiple calls to isValidPath() in one.
This matters when using the Nix daemon because it reduces latency.
For instance, on "nix-env -qas \*" it reduces execution time from 5.7s
to 4.7s (which is indistinguishable from the non-daemon case).
2012-07-11 11:08:47 -04:00
Eelco Dolstra
667d5f1936 Rename queryValidPaths() to queryAllValidPaths() 2012-07-11 10:49:04 -04:00
Eelco Dolstra
eb3036da87 Implement querySubstitutablePathInfos() in the daemon
Also removed querySubstitutablePathInfo().
2012-07-11 10:43:24 -04:00
Eelco Dolstra
11800e6198 download-from-binary-cache: parallelise fetching of NAR info files
Getting substitute information using the binary cache substituter has
non-trivial latency overhead.  A package or NixOS system configuration
can have hundreds of dependencies, and in the worst case (when the
local info cache is empty) we have to do a separate HTTP request for
each of these.  If the ping time to the server is t, getting N info
files will take tN seconds; e.g., with a ping time of 0.1s to
nixos.org, sequentially downloading 1000 info files (a typical NixOS
config) will take at least 100 seconds.

To fix this problem, the binary cache substituter can now perform
requests in parallel.  This required changing the substituter
interface to support a function querySubstitutablePathInfos() that
queries multiple paths at the same time, and rewriting queryMissing()
to take advantage of parallelism.  (Due to local caching,
parallelising queryMissing() is sufficient for most use cases, since
it's almost always called before building a derivation and thus fills
the local info cache.)

For example, parallelism speeds up querying all 1056 paths in a
particular NixOS system configuration from 116s to 2.6s.  It works so
well because the eccentricity of the top-level derivation in the
dependency graph is only 9.  So we only need 10 round-trips (when
using an unlimited number of parallel connections) to get everything.

Currently we do a maximum of 150 parallel connections to the server.
Thus it's important that the binary cache server (e.g. nixos.org) has
a high connection limit.  Alternatively we could use HTTP pipelining,
but WWW::Curl doesn't support it and libcurl has a hard-coded limit of
5 requests per pipeline.
2012-07-06 19:08:20 -04:00
Eelco Dolstra
4bc4da331a Reserve some disk space for the garbage collector
We can't open a SQLite database if the disk is full.  Since this
prevents the garbage collector from running when it's most needed, we
reserve some dummy space that we can free just before doing a garbage
collection.  This actually revives some old code from the Berkeley DB
days.

Fixes #27.
2012-05-29 22:59:12 -04:00
Eelco Dolstra
6387830c3b Merge pull request #2 from viric/master
Again, adding the sync option
2012-04-23 03:29:03 -07:00
Eelco Dolstra
117670be57 Make the garbage collector more concurrent
Make the garbage collector more concurrent by deleting valid paths
outside the region where we're holding the global GC lock.  This
should greatly reduce the time during which new builds are blocked,
since the deletion accounts for the vast majority of the time spent in
the GC.

To ensure that this is safe, the valid paths are invalidated and
renamed to some arbitrary path while we're holding the lock.  This
ensures that we when we finally delete the path, it's not a (newly)
valid or locked path.
2012-03-26 20:43:33 +02:00
Lluís Batlle i Rossell
85799bf89e Fixing the default of sync-before-registering
Setting 'false' as default, as suggested by Eelco.

I also added a comment about the setting in the code.
2012-03-22 20:05:54 +01:00
Lluís Batlle i Rossell
25de80e2b6 Adding a nix option to sync before registering a path, for non-ext*
filesystems.
2012-03-22 19:57:42 +01:00
Eelco Dolstra
19d9762ad5 nix-store --clear-failed-paths: Clear derivation outputs
If the argument to ‘nix-store --clear-failed-paths’ is a derivation,
then clear the failed state of its outputs.
2012-03-20 18:23:26 +01:00
Eelco Dolstra
2b4964f319 Restore progress indication during nix-copy-closure 2012-03-05 18:13:44 +01:00
Eelco Dolstra
8afd28a922 Remove dependency on sqlite3_table_column_metadata
Not all SQLite builds have the function sqlite3_table_column_metadata.
We were only using it in a schema upgrade check for compatibility with
databases that were probably never seen in the wild.  So remove it.
2012-03-01 16:06:49 +01:00
Eelco Dolstra
bd013b6f98 On Linux, make the Nix store really read-only by using the immutable bit
I was bitten one time too many by Python modifying the Nix store by
creating *.pyc files when run as root.  On Linux, we can prevent this
by setting the immutable bit on files and directories (as in ‘chattr
+i’).  This isn't supported by all filesystems, so it's not an error
if setting the bit fails.  The immutable bit is cleared by the garbage
collector before deleting a path.  The only tricky aspect is in
optimiseStore(), since it's forbidden to create hard links to an
immutable file.  Thus optimiseStore() temporarily clears the immutable
bit before creating the link.
2012-02-15 01:31:56 +01:00
Eelco Dolstra
5e57047d87 Fix a broken guard around utime()
Because of an outdated check for a timestamp of 0, we were calling
utime() even when it wasn't necessary.
2012-02-15 01:00:30 +01:00
Eelco Dolstra
b1004f40f7 * Reject a build if there is a cycle among the outputs. This is
necessary because existing code assumes that the references graph is
  acyclic.
2011-12-30 14:47:14 +00:00
Eelco Dolstra
194d21f9f6 * Sync with the trunk. 2011-12-16 23:33:01 +00:00
Eelco Dolstra
273b288a7e * importPath() -> importPaths(). Because of buffering of the input
stream it's now necessary for the daemon to process the entire
  sequence of exported paths, rather than letting the client do it.
2011-12-16 22:31:25 +00:00
Eelco Dolstra
e0bd307802 * Make the import operation through the daemon much more efficient
(way fewer roundtrips) by allowing the client to send data in bigger
  chunks.
* Some refactoring.
2011-12-16 19:44:13 +00:00
Eelco Dolstra
5a1b9ed0aa * Refactoring: move sink/source buffering into separate classes.
* Buffer the HashSink.  This speeds up hashing a bit because it
  prevents lots of calls to the hash update functions (e.g. nix-hash
  went from 9.3s to 8.7s of user time on the closure of my
  /var/run/current-system).
2011-12-15 16:19:53 +00:00
Eelco Dolstra
c8c0380744 * Remove unnecessary quotes. showPaths() already adds quotes. 2011-12-05 21:04:20 +00:00
Eelco Dolstra
000160f5b9 * In ‘nix-store --verify --check-contents’, repair missing hashes
rather than complain about them.
2011-12-02 17:52:18 +00:00
Eelco Dolstra
5bbd693cae * Add an API function exportPaths() that provides the functionality of
‘nix-store --export’.
* Add a Perl module that provides the functionality of
  ‘nix-copy-closure --to’.  This is used by build-remote.pl so it no
  longer needs to start a separate nix-copy-closure process.  Also, it
  uses the Perl API to do the export, so it doesn't need to start a
  separate nix-store process either.  As a result, nix-copy-closure
  and build-remote.pl should no longer fail on very large closures due
  to an "Argument list too long" error.  (Note that having very many
  dependencies in a single derivation can still fail because the
  environment can become too large.  Can't be helped though.)
2011-11-23 15:13:37 +00:00
Eelco Dolstra
c0b706213d * Boldly make SQLite WAL mode the default again. Hopefully the
intermittent problems are gone by now.  WAL mode is preferrable
  because it does way fewer fsyncs.
2011-11-07 21:11:59 +00:00
Shea Levy
af2e53fd48 Include all outputs of derivations in the closure of explicitly-passed derivation paths
This required adding a queryOutputDerivationNames function in the store API
2011-11-06 06:28:20 +00:00
Eelco Dolstra
13114daa3e * Ouch. A store upgrade could cause a substituter to be triggered,
causing a deadlock.
2011-09-12 09:07:43 +00:00
Eelco Dolstra
93227ff65c * Eliminate all uses of the global variable ‘store’ from libstore.
This should also fix:

    nix-instantiate: ./../boost/shared_ptr.hpp:254: T* boost::shared_ptr<T>::operator->() const [with T = nix::StoreAPI]: Assertion `px != 0' failed.

  which was caused by hashDerivationModulo() calling the ‘store’
  object (during store upgrades) before openStore() assigned it.
2011-08-31 21:11:50 +00:00
Eelco Dolstra
b2027f70d9 * Fix a huuuuge security hole in the Nix daemon. It didn't check that
derivations added to the store by clients have "correct" output
  paths (meaning that the output paths are computed by hashing the
  derivation according to a certain algorithm).  This means that a
  malicious user could craft a special .drv file to build *any*
  desired path in the store with any desired contents (so long as the
  path doesn't already exist).  Then the attacker just needs to wait
  for a victim to come along and install the compromised path.

  For instance, if Alice (the attacker) knows that the latest Firefox
  derivation in Nixpkgs produces the path

    /nix/store/1a5nyfd4ajxbyy97r1fslhgrv70gj8a7-firefox-5.0.1

  then (provided this path doesn't already exist) she can craft a .drv
  file that creates that path (i.e., has it as one of its outputs),
  add it to the store using "nix-store --add", and build it with
  "nix-store -r".  So the fake .drv could write a Trojan to the
  Firefox path.  Then, if user Bob (the victim) comes along and does

    $ nix-env -i firefox
    $ firefox

  he executes the Trojan injected by Alice.

  The fix is to have the Nix daemon verify that derivation outputs are
  correct (in addValidPath()).  This required some refactoring to move
  the hash computation code to libstore.
2011-07-20 18:10:47 +00:00
Eelco Dolstra
c931a7aec5 * Do a short sleep after SQLITE_BUSY. 2010-12-17 17:23:15 +00:00
Eelco Dolstra
3dd02580e3 * I forgot to catch SQLiteBusy in registerValidPaths(). So
registerValidPaths() now handles busy errors and registerValidPath()
  is simply a wrapper around it.
2010-12-14 13:25:20 +00:00
Eelco Dolstra
5833243c92 * Create /nix/var/nix/db if it's missing. 2010-12-13 13:42:34 +00:00
Eelco Dolstra
e4720b1a79 * Ignore the result of sqlite3_reset(). 2010-12-08 18:19:15 +00:00