FS_POSIX.createNewFile(File) failed to properly implement atomic file
creation on NFS using the algorithm [1]:
- name of the hard link must be unique to prevent that two processes
using different NFS clients try to create the same link. This would
render nlink useless to detect if there was a race.
- the hard link must be retained for the lifetime of the file since we
don't know when the state of the involved NFS clients will be
synchronized. This depends on NFS configuration options.
To fix these issues we need to change the signature of createNewFile
which would break API. Hence deprecate the old method
FS.createNewFile(File) and add a new method createNewFileAtomic(File).
The new method returns a LockToken which needs to be retained by the
caller (LockFile) until all involved NFS clients synchronized their
state. Since we don't know when the NFS caches are synchronized we need
to retain the token until the corresponding file is no longer needed.
The LockToken must be closed after the LockFile using it has been
committed or unlocked. On Posix, if core.supportsAtomicCreateNewFile =
false this will delete the hard link which guarded the atomic creation
of the file. When acquiring the lock fails ensure that the hard link is
removed.
[1] https://www.time-travellers.org/shane/papers/NFS_considered_harmful.html
also see file creation flag O_EXCL in
http://man7.org/linux/man-pages/man2/open.2.html
Change-Id: I84fcb16143a5f877e9b08c6ee0ff8fa4ea68a90d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
When core.supportsAtomicCreateNewFile was set to false and the
repository was located on a filesystem which doesn't support the file
attribute "unix:nlink" then FS_POSIX#createNewFile may report an error
even if everything was ok. Modify FS_POSIX#createNewFile to silently
ignore this situation. An example of such a filesystem is sshfs where
reading "unix:nlink" always returns 1 (instead of throwing a exception).
Bug: 537969
Change-Id: I6deda7672fa7945efa8706ea1cd652272604ff19
Also-by: Thomas Wolf <thomas.wolf@paranor.ch>
I88304d34c and Ia555bce00 modified the way errors are handled when
trying to delete non-empty reference folders. Before, this error was
silently ignored as it was considered an expected output. Now, every
failed folder delete is logged which can be noisy.
Ignore the DirectoryNotEmptyException but log any other error avoiding
deletion of an eligible folder.
Signed-off-by: Hector Oswaldo Caballero <hector.caballero@ericsson.com>
Change-Id: I194512f67885231d62c03976ae683e5cc450ec7c
* stable-4.7:
Bazel: Use hyphen instead of underscore in external repository names
Bazel: Format all build files with buildifier 0.15.0
ChangeIdUtilTest: Remove unused notestCommitDashV
Change-Id: I414ade902dc38b696c566dd604000e3d289f3973
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Recent Bazel versions support the hyphen character in external
repository names. On the Gerrit project, the repository names
were harmonized to consistently use hyphen.
As a side effect, it is no longer possible to build jgit from source
in the gerrit tree, due to the different repository names.
Rename the dependencies to use hyphens, consistent with gerrit.
Change-Id: Ideebd858ddd3f0e6f765643001642dfb6c12441f
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
This test was never being run. Since it was introduced it was
named "notest.." which meant it didn't run with JUnit3, and
since it is not annotated @Test it also doesn't run with JUnit4.
When compiling with Bazel 0.6.0, error-prone raises an error
that the public method is not annotated with @Ignore or @Test.
Given that the test has never been run anyway, we can just
remove it.
Bug: 525415
Change-Id: Ie9a54f89fe42e0c201f547ff54ff1d419ce37864
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* stable-4.7:
Fix GC run in foreground to not use executor
Change-Id: Ib150d132e2ce055d36ddffb2dbc37b5cb355e77a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Since I3870cadb4, GC task was always delegated to an executor even when
background option was set to false. This was an issue because if more
than one GC object was instantiated and executed in parallel, only one GC
was actually running because of the single thread executor.
Change-Id: I8c587d22d63c1601b7d75914692644a385cd86d6
Signed-off-by: Hugo Arès <hugo.ares@ericsson.com>
* stable-4.7:
Prepare 4.7.3-SNAPSHOT builds
JGit v4.7.2.201807261330-r
Delete all loose refs empty directories
Use java.nio to delete path to get detailed errors
GC: Remove empty references folders
Do not ignore path deletion errors
Change-Id: Iadc8275fbaa3d6f7d08a96ab66d49f392f6aab78
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Remove completely the empty directories under refs/<namespace>
including the first level partition of the changes, when they are
completely empty.
Bug: 536777
Change-Id: I88304d34cc42435919c2d1480258684d993dfdca
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Get the full IOException of the reason why a directory
cannot be removed during GC.
Change-Id: Ia555bce009fa48087a73d677f1ce3b9c0b685b57
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
After packaging references, the folders containing these references are
not deleted. In a busy repository, this causes operations to slow down
as traversing the references tree becomes longer.
Delete empty reference folders after the loose references have been
packed.
To avoid deleting a folder that was just created by another concurrent
operation, only delete folders that were not modified in the last 30
seconds.
Signed-off-by: Hector Oswaldo Caballero <hector.caballero@ericsson.com>
Change-Id: Ie79447d6121271cf5e25171be377ea396c7028e0
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Log as warning when an attempt to remove a directory
fails. This helps troubleshooting some bugs like the GC leaving
behind empty directories.
Change-Id: Idb94ce17f8be9668a970c7ecae31436bf434073c
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
* stable-4.7:
ResolveMerger: Fix encoding with string; use bytes
Change-Id: If17328fbd101d596a8a16d9c4a190e9b6e120902
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
This change fixes the issue [1]. Before this fix, a merge involving
the caching of consecutive yet similar filenames with Norwegian
characters [2] used to throw an IllegalStateException: Duplicate
stages not allowed. This was caused by inaccurate decoding of the
filenames, using string values assuming default encoding. In the
toString method of DirCacheEntry, used before through getPathString,
UTF-8 encoding is used, but the end result becomes default encoding,
through Object's default toString usage. The special characters in
those two consecutive (particular) filenames [2] were becoming the
very same decoded /single character, lending consecutive -but then
identical- filenames. Thus the perceived duplicate 0-staging of the
file(s).
Replace getPathString usage with getRawPath for this specific case,
or use byte array representations of cached entries instead of string.
Adding a test for this change is not possible, as there is no known
way to change the default encoding for filenames such as [2] (e.g.).
JGitTestUtil does write file contents through UTF-8, but encoding like
so does not apply to the actual file name. Hence there is no way to
create files with names properly made of special characters such as
[2]'s. And the test that is necessary for this case assumes such
Norwegian (or similar characters) filenames. Changing the default
locale programmatically in a test has no effect either. And changing
the LANG value passed to the JVM is only possible upon starting it.
[1] https://bugs.chromium.org/p/gerrit/issues/detail?id=9153
[2] <=>
(...)
"a/b/SíÒr-Norge.map",
"a/b/Sør-Norge.map",
(...)
Change-Id: Ib9f2f5297932337c9817064cc09d9f774dd168f4
Signed-off-by: Marco Miller <marco.miller@ericsson.com>
On a local non-NFS filesystem the .git/config file will be orphaned if
it is replaced by a new process while the current process is reading the
old file. The current process successfully continues to read the
orphaned file until it closes the file handle.
Since NFS servers do not keep track of open files, instead of orphaning
the old .git/config file, such a replacement on an NFS filesystem will
instead cause the old file to be garbage collected (deleted). A stale
file handle exception will be raised on NFS clients if the file is
garbage collected (deleted) on the server while it is being read. Since
we no longer have access to the old file in these cases, the previous
code would just fail. However, in these cases, reopening the file and
rereading it will succeed (since it will open the new replacement file).
Since retrying the read is a viable strategy to deal with stale file
handles on the .git/config file, implement such a strategy.
Since it is possible that the .git/config file could be replaced again
while rereading it, loop on stale file handle exceptions, up to 5 extra
times, trying to read the .git/config file again, until we either read
the new file, or find that the file no longer exists. The limit of 5 is
arbitrary, and provides a safe upper bounds to prevent infinite loops
consuming resources in a potential unforeseen persistent error
condition.
Change-Id: I6901157b9dfdbd3013360ebe3eb40af147a8c626
Signed-off-by: Nasser Grainawi <nasser@codeaurora.org>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
When running on NFS there was a chance that JGits LockFile
semantic is broken because File#createNewFile() may allow
multiple clients to create the same file in parallel. This
change provides a fix which is only used when the new config
option core.supportsAtomicCreateNewFile is set to false. The
default for this option is true. This option can only be set in the
global or the system config file. The repository config file is not
taken into account in this case.
If the config option core.supportsAtomicCreateNewFile is true
then File#createNewFile() is trusted and the behaviour doesn't
change.
But if core.supportsAtomicCreateNewFile is set to false then after
successful creation of the lock file a hardlink to that lock file is
created and the attribute nlink of the lock file is checked to be 2. If
multiple clients manage to create the same lock file nlink would be
greater than 2 showing the error.
This expensive workaround is described in
https://www.time-travellers.org/shane/papers/NFS_considered_harmful.html
section III.d) "Exclusive File Creation"
Change-Id: I3d2cc48d8eb280d5f7039eb94da37804f903be6a
Then list of packed refs was cached in RefDirectory based on mtime of
the packed-refs file. This may fail on NFS when attributes are cached.
A cached mtime of the packed-refs file could cause JGit to trust the
cached content of this file and to overlook that the file is modified.
Honor the config option trustFolderStats and always read the packed-refs
content if the option is false. By default this option is set to true
and this fix is not active.
Change-Id: I2b65cfaa8f4aba2efbf8a5e865d3f09f927e2eec
When creating a new PackFile instance it is specified whether this pack
has an associated bitmap index file or not. This information is cached
and the public method getBitmapIndex() will always assume a bitmap index
file must exist if the cached data tells so. But it may happen that the
packfiles are repacked during a gc in a different process causing the
packfile, bitmap-index and index file to be deleted. Since JGit still
has an open FileHandle on the packfile this file is not really deleted
and can still be accessed. But index and bitmap index file are deleted.
Fix getBitmapIndex() to invalidate the cached packfile instance if such
a situation occurs.
This problem showed up when a gerrit server was serving repositories
which where garbage collected with native git regularly. Fetch and
clone commands for certain repositories failed permanently after a
native git gc had deleted old bitmap index files.
Change-Id: I8e620bec74dd3f310ba42024f9a657062f868f0e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
WorkQueue uses daemon threads so auto-gc would not be executed after
short-lived commands run in command line. Hence use a dedicated executor
which we shutdown when the command finishes.
Change-Id: I0c2429ecfa04387389d159168ba78a020a696228
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
If set use the external executor, otherwise use JGit's own simple
WorkQueue. Move WorkQueue to an internal package so we can reuse it
without exposing it in the public API.
Change-Id: I060d62ffd6692362a88b4bf13ee07b0dc857abe9
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Add options to control recursion into submodules on fetch.
Add a callback interface on FetchCommand, to allow Fetch to display
an update "Fetching submodule XYZ" for each submodule.
Change-Id: Id805044b57289ee0f384b434aba1dbd2fd317e5b
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Matthias Sohn
Christian Halstrick
Hector Caballero
David Pursehouse
Hugo Arès
Luca Milanesio
Marco Miller
Dave Borowitz
Nasser Grainawi