This is a mostly pointless change to make security scanners and static
analysis tools happy, as they all hate seeing md5. None of our md5 uses
were security relevant, but still. Only visible effect of this change is
that our temp file names for very long file names become slightly longer
than they were previously...
The test would fail if the umask on UNIX is greater than 0022, because
the OS transparently subtracts it from the mode passed to Mkdir(), as
the Go documentation confirms.
Our goal here is not to test os.Mkdir(), so just make sure the desired
mode is actually set by forcing it afterwards.
COM0 and LPT0 are not listed in the official Microsoft's documentation
at https://docs.microsoft.com/windows/win32/fileio/naming-a-file, but
in reality are also invalid in Windows Explorer.
Signed-off-by: Tomasz Wilczyński <twilczynski@naver.com>
Add specific errors for the failures, resulting in this rather than just
the generic "invalid filename":
[MRIW7] 08:50:50 INFO: Puller (folder default, item "NUL"): syncing: filename is invalid: name is reserved
[MRIW7] 08:50:50 INFO: Puller (folder default, item "fail."): syncing: filename is invalid: name ends with space or period
[MRIW7] 08:50:50 INFO: Puller (folder default, item "sup:yo"): syncing: filename is invalid: name contains reserved character
[MRIW7] 08:50:50 INFO: default: Failed to sync 3 items
Use the IoctlFileClone and IoctlFileCloneRange ioctl wrappers and the
FileCloneRange type provided by golang.org/x/sys/unix instead of
locally implementing them. This also allows to re-enable the code for
ppc/ppc64/ppc64le again (see commit 758a1a6a37 ("lib/fs: Disable ioctl
on ppc (fixes#6898) (#6901)")) since golang.org/x/sys/unix internally
uses the correct FICLONE and FICLONERANGE values depending on $GOARCH.
Most notably, it now detects all-lowercase files and returns these
as-is. The tests have been expanded with two cases and are now used
as a benchmark (admittedly a rather trivial one).
name old time/op new time/op delta
UnicodeLowercaseMaybeChange-8 4.59µs ± 2% 4.57µs ± 1% ~ (p=0.197 n=10+10)
UnicodeLowercaseNoChange-8 3.26µs ± 1% 3.09µs ± 1% -5.27% (p=0.000 n=9+10)
This changes the cache to cache less things, yet retain the required
efficiency for our walk usecase. This uses less memory.
Specifically, instead of keeping result and child caches for each path
level, only keep a single cached child. In practice our operations are
depth-first, or almost depth-first, and then we retain the same hit
ratio for a smaller cache size.
I improved the benchmark so that it counts the Lstat and DirNames
operations performed, and they do not change significantly. The amount
of allocated memory is reduced by 20% and the walk itself is actually
slightly faster.
This also removes the clear based on number of cached names (as that is
not a thing any more) and the timer based clear (which was unused). This
means we'll retain the last cache state forever until it's cleared by a
write operation, but we did that before too and that state is now a lot
smaller...
The overhead compared to not using a casefs, for our typical "double
walk" (walk the tree then stat everything again) is 2x the dirnames we
would otherwise call, and no overhead on the stats (unchanged from old
implementation)
```
name old time/op new time/op delta
WalkCaseFakeFS100k/rawfs-8 306ms ± 1% 305ms ± 2% ~ (p=0.182 n=9+10)
WalkCaseFakeFS100k/casefs-8 579ms ± 5% 557ms ± 1% -3.77% (p=0.000 n=10+10)
name old B/entry new B/entry delta
WalkCaseFakeFS100k/rawfs-8 590 ± 0% 590 ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 1.09k ± 0% 0.87k ± 0% -19.98% (p=0.000 n=10+10)
name old DirNames/entry new DirNames/entry delta
WalkCaseFakeFS100k/rawfs-8 0.51 ± 0% 0.51 ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 1.02 ± 0% 1.02 ± 0% ~ (all equal)
name old DirNames/op new DirNames/op delta
WalkCaseFakeFS100k/rawfs-8 51.2k ± 0% 51.2k ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 102k ± 0% 102k ± 0% ~ (all equal)
name old Lstat/entry new Lstat/entry delta
WalkCaseFakeFS100k/rawfs-8 3.02 ± 0% 3.02 ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 3.02 ± 0% 3.02 ± 0% ~ (all equal)
name old Lstat/op new Lstat/op delta
WalkCaseFakeFS100k/rawfs-8 302k ± 0% 302k ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 302k ± 0% 302k ± 0% ~ (all equal)
name old allocs/entry new allocs/entry delta
WalkCaseFakeFS100k/rawfs-8 15.7 ± 0% 15.7 ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 27.5 ± 0% 26.1 ± 0% -5.09% (p=0.000 n=10+10)
name old ns/entry new ns/entry delta
WalkCaseFakeFS100k/rawfs-8 2.02k ± 1% 2.02k ± 2% ~ (p=0.163 n=9+10)
WalkCaseFakeFS100k/casefs-8 3.83k ± 5% 3.68k ± 1% -3.77% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
WalkCaseFakeFS100k/rawfs-8 89.2MB ± 0% 89.2MB ± 0% ~ (p=0.364 n=9+10)
WalkCaseFakeFS100k/casefs-8 164MB ± 0% 131MB ± 0% -19.97% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
WalkCaseFakeFS100k/rawfs-8 2.38M ± 0% 2.38M ± 0% ~ (all equal)
WalkCaseFakeFS100k/casefs-8 4.16M ± 0% 3.95M ± 0% -5.05% (p=0.000 n=10+10)
```
With this change we emulate a case sensitive filesystem on top of
insensitive filesystems. This means we correctly pick up case-only renames
and throw a case conflict error when there would be multiple files differing
only in case.
This safety check has a small performance hit (about 20% more filesystem
operations when scanning for changes). The new advanced folder option
`caseSensitiveFS` can be used to disable the safety checks, retaining the
previous behavior on systems known to be fully case sensitive.
Co-authored-by: Jakob Borg <jakob@kastelo.net>
Prompted by https://forum.syncthing.net/t/infinite-filesystem-recursion-detected/15285. In my opinion the filesystem shouldn't throw warnings but pass on errors for the caller to decide what's to be happening with it. Right now in this PR an infinite recursion is a normal scan error, i.e. folder is in failed state and displays failed items, but no warning. I think that's appropriate but if deemed appropriate an additional warning can be thrown in the scanner.
- In the few places where we wrap errors, use the new Go 1.13 "%w"
construction instead of %s or %v.
- Where we create errors with constant strings, consistently use
errors.New and not fmt.Errorf.
- Remove capitalization from errors in the few places where we had that.
During some other work I discovered these tests weren't great, so I've
rewritten them to be a little better. The real changes here are:
- Don't play games with not starting the folder and such, and don't
construct a fake folder instance -- just use the one the model has. The
folder starts and scans but the folder contents are empty at this point
so that's fine.
- Use a fakefs instead of a temp dir.
- To support the above, implement a fakefs option `?content=true` to
make the fakefs actually retain written content. Use sparingly,
obviously, but it means the fakefs can usually be used instead of an
on disk real directory.
As foretold by the prophecy, "once the database refactor is merged, then
shall appear a request to propagate errors from the store known
throughout the land as the NamedspacedKV, and it shall be good".
This PR does two things, because one lead to the other:
- Move the leveldb specific stuff into a small "backend" package that
defines a backend interface and the leveldb implementation. This allows,
potentially, in the future, switching the db implementation so another
KV store should we wish to do so.
- Add proper error handling all along the way. The db and backend
packages are now errcheck clean. However, I drew the line at modifying
the FileSet API in order to keep this manageable and not continue
refactoring all of the rest of Syncthing. As such, the FileSet methods
still panic on database errors, except for the "database is closed"
error which is instead handled by silently returning as quickly as
possible, with the assumption that we're anyway "on the way out".
* lib/fs, lib/model: Add error channel to Watch to avoid panics (fixes#5697)
* forgot unsupported watch
* and more non(-standard)-unixy fixes
* and windows test
* review
This adds a folder option "CopyOwnershipFromParent" which, when set,
makes Syncthing attempt to retain the owner/group information when
syncing files. Specifically, at the finisher stage we look at the parent
dir to get owner/group and then attempt a Lchown call on the temp file.
For this to succeed Syncthing must be running with the appropriate
permissions. On Linux this is CAP_FOWNER, which can be granted by the
service manager on startup or set on the binary in the filesystem. Other
operating systems do other things, but often it's not required to run as
full "root". On Windows this patch does nothing - ownership works
differently there and is generally less of a deal, as permissions are
inherited as ACLs anyway.
There are unit tests on the Lchown functionality, which requires the
above permissions to run. There is also a unit test on the folder which
uses the fake filesystem and hence does not need special permissions.
* lib/fs: Add fakefs
This adds a new fake filesystem type. It's described rather extensively
in fakefs.go, but the main point is that it's for testing: when you want
to spin up a Syncthing and have a terabyte or two of random files that
can be synced somewhere, or an inifitely large filesystem to sync files
into.
It has pseudorandom properties such that data read from one fakefs can
be written into another fakefs and read back and it will look
consistent, without any of the data actually being stored.
To use:
<folder id="default" path="whatever" ...>
<filesystemType>fake</filesystemType>
This will create an empty fake filesystem. You can also specify that it
should be prefilled with files:
<folder id="default" path="whatever?size=2000000" ...>
<filesystemType>fake</filesystemType>
This will create a filesystem filled with 2TB of random data that can be
scanned and synced. There are more options, see fakefs.go.
Prefilled data is based on a deterministic seed, so you can index the
data and restart Syncthing and the index is still correct for all the
stored data.
Given that we've taken on the resposibility of maintaining this forked
package I've added it to the Syncthing organization. We still vendor it
like an external package, because it's convenient to keep it as a fork
of upstream to easier merge and file pull requests towards them.
When scanner.Walk detects a change, it now returns the new file info as well as the old file info. It also finds deleted and ignored files while scanning.
Also directory deletions are now always committed to db after their children to prevent temporary failure on remote due to non-empty directory.
This removes a number of timing related things, leaving just the total
test timeout now bumped to one minute. Normally we get the filesystem
events within a second or so, so this doesn't affect the test time in
the successfull case. If we don't actually get the events we expect
within a minute I think we are legitimately in "failed" territory.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4715
LGTM: imsodin, AudriusButkevicius
It turns out that ZFS doesn't do any normalization when storing files,
but does do normalization "as part of any comparison process".
In practice, this seems to mean that if you LStat a normalized filename,
ZFS will return the FileInfo for the un-normalized version of that
filename.
This meant that our test to see whether a separate file with a
normalized version of the filename already exists was failing, as we
were detecting the same file.
The fix is to use os.SameFile, to see whether we're getting the same
FileInfo from the normalized and un-normalized versions of the same
filename.
One complication is that ZFS also seems to apply its magic to os.Rename,
meaning that we can't use it to rename an un-normalized file to its
normalized filename. Instead we have to move via a temporary object. If
the move to the temporary object fails, that's OK, we can skip it and
move on. If the move from the temporary object fails however, I'm not
sure of the best approach: the current one is to leave the temporary
file name as-is, and get Syncthing to syncronize it, so at least we
don't lose the file. I'm not sure if there are any implications of this
however.
As part of reworking normalizePath, I spotted that it appeared to be
returning the wrong thing: the doc and the surrounding code expecting it
to return the normalized filename, but it was returning the
un-normalized one. I fixed this, but it seems suspicious that, if the
previous behaviour was incorrect, noone ever ran afoul of it. Maybe all
filesystems will do some searching and give you a normalized filename if
you request an unnormalized one.
As part of this, I found that TestNormalization was broken: it was
passing, when in fact one of the files it should have verified was
present was missing. Maybe this was related to the above issue with
normalizePath's return value, I'm not sure. Fixed en route.
Kindly tested by @khinsen on the forum, and it appears to work.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4646
