To enable persisting the minimal racy threshold per FileStore add a
new config option to the user global git configuration:
- Config section is "filesystem"
- Config subsection is concatenation of
- Java vendor (system property "java.vendor")
- Java version (system property "java.version")
- FileStore's name, on Windows we use the attribute volume:vsn instead
since the name is not necessarily unique.
- separated by '|'
e.g.
"AdoptOpenJDK|1.8.0_212-b03|/dev/disk1s1"
The same prefix is used as for filesystem timestamp resolution, so
both values are stored in the same config section
- The config key for minmal racy threshold is "minRacyThreshold" as a
time value, supported time units are those supported by
DefaultTypedConfigGetter#getTimeUnit
- measure for 3 seconds to limit runtime which depends on hardware, OS
and Java version being used
If the minimal racy threshold is configured for a given FileStore the
configured value is used instead of measuring it.
When the minimal racy threshold was measured it is persisted in the user
global git configuration.
Rename FileStoreAttributeCache to FileStoreAttributes since this class
is now declared public in order to enable exposing all attributes in one
object.
Example:
[filesystem "AdoptOpenJDK|11.0.3|/dev/disk1s1"]
timestampResolution = 7000 nanoseconds
minRacyThreshold = 3440 microseconds
Change-Id: I22195e488453aae8d011b0a8e3276fe3d99deaea
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Also-By: Marc Strapetz <marc.strapetz@syntevo.com>
By running FileSnapshotTest#detectFileModified we found that the sum of
measured filesystem timestamp resolution and measured clock resolution
may yield a too small interval after a file has been modified which we
need to consider racily clean. In our tests we didn't find this behavior
on all systems we tested on, e.g. on MacOS using APFS and Java 8 and 11
this effect was not observed.
On Linux (SLES 15, kernel 4.12.14-150.22-default) we collected the
following test results using Java 8 and 11:
In 23-98% of 10000 test runs (depending on filesystem type and Java
version) the test failed, which means the effective interval which needs
to be considered racily clean after a file was modified is larger than
the measured file timestamp resolution.
"delta" is the observed interval after a file has been modified but
FileSnapshot did not yet detect the modification:
"resolution" is the measured sum of file timestamp resolution and clock
resolution seen in Java.
Java version filesystem failures resolution min delta max delta
1.8.0_212-b04 btrfs 98.6% 1 ms 3.6 ms 6.6 ms
1.8.0_212-b04 ext4 82.6% 3 ms 1.1 ms 4.1 ms
1.8.0_212-b04 xfs 23.8% 4 ms 3.7 ms 3.9 ms
1.8.0_212-b04 zfs 23.1% 3 ms 4.8 ms 5.0 ms
11.0.3+7 btrfs 98.1% 3 us 0.7 ms 4.7 ms
11.0.3+7 ext4 98.1% 6 us 0.7 ms 4.7 ms
11.0.3+7 xfs 98.5% 7 us 0.1 ms 8.0 ms
11.0.3+7 zfs 98.4% 7 us 0.7 ms 5.2 ms
Mac OS
1.8.0_212 APFS 0% 1 s
11.0.3+7 APFS 0% 6 us
The observed delta is not distributed according to a normal gaussian
distribution but rather random in the observed range between "min delta"
and "max delta".
Run this test after measuring file timestamp resolution in
FS.FileAttributeCache to auto-configure JGit since it's unclear what
mechanism is causing this effect.
In FileSnapshot#isRacyClean use the maximum of the measured timestamp
resolution and the measured "delta" as explained above to decide if a
given FileSnapshot is to be considered racily clean. Add a 30% safety
margin to ensure we are on the safe side.
Change-Id: I1c8bb59f6486f174b7bbdc63072777ddbe06694d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
We should not list the complete cache but only show the cache entry at
hand.
Change-Id: I22be2a4dcbf0145155e23f2389bfcf5662cf23a6
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Measure granularity of timestamps stored in the filesystem by setting
and then getting lastModified timestamp until the read value changed.
Increase increment exponentially to limit number of iterations starting
with 1 microsecond since Java's FileTime (up to Java 12) truncates
timestamps to 1 microsecond resolution. The chosen algorithm yields 2000
steps between 1 ms and 2.5 s.
Also measure clock resolution and add that for the total timestamp
resolution. This avoids systematic measurement errors introduced by
doing IO to touch a file.
Change-Id: I9b37138619422452373e298d9d8c7cb2c384db3f
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
This enables higher file timestamp resolution on filesystems like ext4,
Mac APFS (1ns) or NTFS (100ns) providing high timestamp resolution on
filesystem level.
Note:
- on some OSes Java 8,9 truncate milliseconds, see
https://bugs.openjdk.java.net/browse/JDK-8177809, fixed in Java 10
- UnixFileAttributes truncates timestamp resolution to microseconds when
converting the internal representation to FileTime exposed in the API,
see https://bugs.openjdk.java.net/browse/JDK-8181493
- WindowsFileAttributes also provides only microsecond resolution
Change-Id: I25ffff31a3c6f725fc345d4ddc2f26da3b88f6f2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
On Android FS#getFsTimestampResolution always throws a
SecurityException, handle this by falling back to the fallback timestamp
resolution.
Bug: 548947
Change-Id: I0ee6cb3c20e189bdc8d488434a930427ad6f2df2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
It seems on cygwin creating a file under a writable directory can fail
with AccessDeniedException. Log a warning in this case and fallback to
worst case timestamp resolution of 2 seconds.
Bug: 548648
Change-Id: Ic50c31ce9dc9ccadd4db5247df929418ac62d45c
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Use options
- StandardOpenOption.CREATE to create touched file if not existing
- StandardOpenOption.SYNC to enforce synch of data and meta data changes
- StandardOpenOption.WRITE
Also set mtime explicitly in FileUtils#touch to the current system time.
This should fix that the previous implementation didn't work on
- locally cached Windows network share (CSC-CACHE filesystem) mapped as
a drive
- nfsv4 mounts on Linux
and that it didn't create unborn file like Linux command "touch".
Apache common's and Guava's touch() use the same approach.
Immediately after creating the probe file used to measure timestamp
resolution touch it. This ensures we always use the local system clock
when measuring filesystem timestamp resolution. This should prevent that
clock skew could influence the measured timestamp resolution in case of
a mounted network filesystem.
Bug: 548598
Change-Id: Iaeaf5967963f582395a195aa637b8188bfadac60
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
To enable persisting filesystem timestamp resolution per FileStore add a
new config section to the user global git configuration:
- Config section is "filesystem"
- Config subsection is concatenation of
- Java vendor (system property "java.vm.vendor")
- runtime version (system property "java.vm.version")
- FileStore's name
- separated by '|'
e.g.
"AdoptOpenJDK|1.8.0_212-b03|/dev/disk1s1"
The prefix is needed since some Java versions do not expose the full
timestamp resolution of the underlying filesystem. This may also
depend on the underlying operating system hence concrete key values
may not be portable.
- Config key for timestamp resolution is "timestampResolution" as a time
value, supported time units are those supported by
DefaultTypedConfigGetter#getTimeUnit
If timestamp resolution is already configured for a given FileStore
the configured value is used instead of measuring the resolution.
When timestamp resolution was measured it is persisted in the user
global git configuration.
Example:
[filesystem "AdoptOpenJDK|1.8.0_212-b03|/dev/disk1s1"]
timestampResolution = 1 seconds
If locking the git config file fails retry saving the resolution up to 5
times in order to workaround races with another thread.
In order to avoid stack overflow use the fallback filesystem timestamp
resolution when loading FileBasedConfig which creates itself a
FileSnapshot to help checking if the config changed.
Note:
- on some OSes Java 8,9 truncate to milliseconds or seconds, see
https://bugs.openjdk.java.net/browse/JDK-8177809, fixed in Java 10
- UnixFileAttributes up to Java 12 truncates timestamp resolution to
microseconds when converting the internal representation to FileTime
exposed in the API, see https://bugs.openjdk.java.net/browse/JDK-8181493
- WindowsFileAttributes also provides only microsecond resolution up to
Java 12
Hence do not attempt to manually configure a higher timestamp resolution
than supported by the Java version being used at runtime.
Bug: 546891
Bug: 548188
Change-Id: Iff91b8f9e6e5e2295e1463f87c8e95edf4abbcf8
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
In order to avoid blocking on the main thread during measurement
interactive applications like EGit may want to measure the filesystem
timestamp resolution asynchronously.
In order to enable measurement in the background call
FileStoreAttributeCache.setAsyncfileStoreAttrCache(true)
before the first access to cached FileStore attributes.
Bug: 548188
Change-Id: I8c9a2dbfc3f1d33441edea18b90e36b1dc0156c7
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
It was reported that measuring file timestamp resolution may hang
indefinitely on nfs. Hence timeout this measurement at the known worst
filesystem timestamp resolution (FAT) of 2 seconds.
Bug: 548188
Change-Id: I17004b0aa49d5b0e76360a008af3adb911b289c0
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
FileSnapshot.notRacyClean() assumed a worst case filesystem timestamp
resolution of 2.5 sec (FAT has a resolution of 2 sec). Instead measure
timestamp resolution to avoid unnecessary IO caused by false positives
in detecting the racy git problem caused by finite filesystem timestamp
resolution [1].
Cache the measured resolution per FileStore since timestamp resolution
depends on the respective filesystem type. If timestamp resolution
cannot be measured or fails due to an exception fallback to the worst
case FAT timestamp resolution and avoid caching this value.
Add a 10% safety margin in FileSnapshot.notRacyClean(), though running
FsTest.testFsTimestampResolution() 1000 times which is not using a
safety margin didn't fail on Mac using APFS and Java 8, 11, 12.
Measured Java file timestamp resolution: [2]
[1] https://github.com/git/git/blob/master/Documentation/technical/racy-git.txt
[2] https://docs.google.com/spreadsheets/d/1imy0y6WmRqBf0kjCxzxj2X7M50eIVfa7oaUIzEOHmjo
Bug: 546891
Change-Id: I493f3b57b6b306285ffa7d392339d253e5966ab8
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-5.0:
Prepare 4.11.8-SNAPSHOT builds
JGit v4.11.7.201903122105-r
Prepare 4.9.10-SNAPSHOT builds
JGit v4.9.9.201903122025-r
Prepare 4.7.9-SNAPSHOT builds
JGit v4.7.8.201903121755-r
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: I71771dcc086a9a0097bad74d65ec71ad97106a38
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.11:
Prepare 4.11.8-SNAPSHOT builds
JGit v4.11.7.201903122105-r
Prepare 4.9.10-SNAPSHOT builds
JGit v4.9.9.201903122025-r
Prepare 4.7.9-SNAPSHOT builds
JGit v4.7.8.201903121755-r
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: I04c70f66c6f1e53bdc199fb5b24c9136c9a8e4f7
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.10:
Prepare 4.9.10-SNAPSHOT builds
JGit v4.9.9.201903122025-r
Prepare 4.7.9-SNAPSHOT builds
JGit v4.7.8.201903121755-r
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: Ic66dc00455c05f7627919f682a7221ffeef1629d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.9:
Prepare 4.9.10-SNAPSHOT builds
JGit v4.9.9.201903122025-r
Prepare 4.7.9-SNAPSHOT builds
JGit v4.7.8.201903121755-r
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: Ifcd8ea6a2b59f6f8e9d896d8407cfcaef0a9375d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.8:
Prepare 4.7.9-SNAPSHOT builds
JGit v4.7.8.201903121755-r
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: I9a47153831f8eb10d3cd91b4157cf45385e5b13a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.7:
Prepare 4.7.9-SNAPSHOT builds
JGit v4.7.8.201903121755-r
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: I1136eaa1590b225ceaf16ba7552af0374253a74e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.6:
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: I3d1544d034783fe0fa1385dfe9b03ad8e9247c63
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.5:
Prepare 4.5.7-SNAPSHOT builds
JGit v4.5.6.201903121547-r
Check for packfile validity and fd before reading
Move throw of PackInvalidException outside the catch
Use FileSnapshot to get lastModified on PackFile
Include size when comparing FileSnapshot
Do not reuse packfiles when changed on filesystem
Silence API warnings for new API introduced for fixes
Change-Id: I029e1797447e6729de68bd89d4d69b324dbb3f5f
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Due to finite filesystem timestamp resolution the last modified
timestamp of files cannot detect file changes which happened in the
immediate past (less than one filesystem timer tick ago).
Read and consider file size also, so that differing file size can help
to more accurately detect file changes without reading the file content.
Use bulk read to avoid multiple stat calls to retrieve file attributes.
Change-Id: I974288fff78ac78c52245d9218b5639603f67a46
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-5.0:
Fix ObjectUploadListener#close
Fix error handling in FileLfsServlet
ObjectDownloadListener#onWritePossible: Make code spec compatible
ObjectDownloadListener: Return from onWritePossible when data is written
Fix IOException when LockToken#close fails
Change-Id: Ib7a63b5144a89c213aff3b32c30a2a6526355e64
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* stable-4.11:
Fix ObjectUploadListener#close
Fix error handling in FileLfsServlet
ObjectDownloadListener#onWritePossible: Make code spec compatible
ObjectDownloadListener: Return from onWritePossible when data is written
Fix IOException when LockToken#close fails
Change-Id: Iffe202a412b3bca1c8d8d7dc5dfd646c49838de9
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* stable-4.10:
Fix ObjectUploadListener#close
Fix error handling in FileLfsServlet
ObjectDownloadListener#onWritePossible: Make code spec compatible
ObjectDownloadListener: Return from onWritePossible when data is written
Fix IOException when LockToken#close fails
Change-Id: I28ebf6138ccd9425fc05319de78c7716f0bdd199
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* stable-4.9:
Fix ObjectUploadListener#close
Fix error handling in FileLfsServlet
ObjectDownloadListener#onWritePossible: Make code spec compatible
ObjectDownloadListener: Return from onWritePossible when data is written
Fix IOException when LockToken#close fails
Change-Id: Ib7d01cb0ece8b259156855045a53b8baf3fa2968
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* stable-4.8:
Fix ObjectUploadListener#close
Fix error handling in FileLfsServlet
ObjectDownloadListener#onWritePossible: Make code spec compatible
ObjectDownloadListener: Return from onWritePossible when data is written
Fix IOException when LockToken#close fails
Change-Id: Id8eb635094336567d9f3c28ec985cd5127d31632
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* stable-4.7:
Fix ObjectUploadListener#close
Fix error handling in FileLfsServlet
ObjectDownloadListener#onWritePossible: Make code spec compatible
ObjectDownloadListener: Return from onWritePossible when data is written
Fix IOException when LockToken#close fails
Change-Id: Iad9836811be034cf992ea25dad4409addba75115
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
This happened if the LockTokens hard link was already deleted earlier.
Bug: 531759
Change-Id: Idc84bd695fac1a763b3cbb797c9c4c636a16e329
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
If some process executed by FS#readPipe ends in an error,
the error stream is never set as errorMessage because
FS#GobblerThread#waitForProcessCompletion always returned true.
This caused LOG#warn to be called with null.
Return false whenever FS#GobblerThread#waitForProcessCompletion fails.
Bug: 538723
Change-Id: Ic9492bd688431d52c8665f7a2efec2989e95a4ce
Signed-off-by: Cliffred van Velzen <cliffred@cliffred.nl>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
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>
Remove it from
* package private functions.
* try blocks
* for loops
this was done with the following python script:
$ cat f.py
import sys
import re
import os
def replaceFinal(m):
return m.group(1) + "(" + m.group(2).replace('final ', '') + ")"
methodDecl = re.compile(r"^([\t ]*[a-zA-Z_ ]+)\(([^)]*)\)")
def subst(fn):
input = open(fn)
os.rename(fn, fn + "~")
dest = open(fn, 'w')
for l in input:
l = methodDecl.sub(replaceFinal, l)
dest.write(l)
dest.close()
for root, dirs, files in os.walk(".", topdown=False):
for f in files:
if not f.endswith('.java'):
continue
full = os.path.join(root, f)
print full
subst(full)
Change-Id: If533a75a417594fc893e7c669d2c1f0f6caeb7ca
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Getting attributes of files on Windows is an expensive operation.
Windows stores file attributes in the directory, so they are
basically available "for free" when a directory is listed. The
implementation of Java's Files.walkFileTree() takes advantage of
that (at least in the OpenJDK implementation for Windows) and
provides the attributes from the directory to a FileVisitor.
Using Files.walkFileTree() with a maximum depth of 1 is thus a
good approach on Windows to get both the file names and the
attributes in one go.
In my tests, this gives a significant speed-up of FileTreeIterator
over the "normal" way: using File.listFiles() and then reading the
attributes of each file individually. The speed-up is hard to
quantify exactly, but in my tests I've observed consistently 30-40%
for staging 500 files one after another, each individually, and up
to 50% for individual TreeWalks with a FileTreeIterator.
On Unix, this technique is detrimental. Unix stores file attributes
differently, and getting attributes of individual files is not costly.
On Unix, the old way of doing a listFiles() and getting individual
attributes (both native operations) is about three times faster than
using walkFileTree, which is implemented in Java.
Therefore, move the operation to FS/FS_Win32 and call it from
FileTreeIterator, so that we can have different implementations
depending on the file system.
A little performance test program is included as a JUnit test (to be
run manually).
While this does speed up things on Windows, it doesn't solve the basic
problem of bug 532300: the iterator always gets the full directory
listing and the attributes of all files, and the more files there are
the longer that takes.
Bug: 532300
Change-Id: Ic5facb871c725256c2324b0d97b95e6efc33282a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
The runProcess method creates an OutputStream that is not managed by
a try-with-resource because it's manually closed and any IOException
raised by the close() method is explicitly ignored.
Suppress the resource warning with an explanatory comment.
Enclose the call to StreamGobbler#copy in an inner try-block, and move
the call to close() inside its finally block. This prevents the stream
from being left unclosed if StreamGobbler#copy raises IOException.
Change-Id: Idca9adfc4d87e0989d787ad8239c055c0c849814
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
If some process executed by FS#readPipe lived for a while after
closing stderr, FS#GobblerThread#run failed with an
IllegalThreadStateException exception when accessing p.exitValue()
for the process which is still alive.
Add Process#waitFor calls to wait for the process completion.
Bug: 528335
Change-Id: I87e0b6f9ad0b995dbce46ddfb877e33eaf3ae5a6
Signed-off-by: Dmitry Pavlenko <pavlenko@tmatesoft.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
* stable-4.9:
Ignore warning for minor version change without API change
Silence boxing warning
Prepare 4.5.5-SNAPSHOT builds
JGit v4.5.4.201711221230-r
Fix LockFile semantics when running on NFS
Honor trustFolderStats also when reading packed-refs
Prepare 4.5.4-SNAPSHOT builds
JGit v4.5.3.201708160445-r
Change-Id: Icc33d2e36f140e8714fce088379673a8834ae9de
Matthias Sohn