From: david-sarah Date: Tue, 25 May 2010 18:42:10 +0000 (-0700) Subject: SFTP: handle removing a file while it is open. Also some simplifications of the logou... X-Git-Tag: trac-4400~3 X-Git-Url: https://git.rkrishnan.org/pf/content/%22news.html/%22doc.html/index.php?a=commitdiff_plain;h=a143b1297bfddf4baa522cb579585927899bd90b;p=tahoe-lafs%2Ftahoe-lafs.git SFTP: handle removing a file while it is open. Also some simplifications of the logout handling. --- diff --git a/src/allmydata/frontends/sftpd.py b/src/allmydata/frontends/sftpd.py index b0e9ba2e..b6ccefb9 100644 --- a/src/allmydata/frontends/sftpd.py +++ b/src/allmydata/frontends/sftpd.py @@ -336,10 +336,9 @@ class OverwriteableFileConsumer(PrefixingLogMixin): This abstraction is mostly independent of SFTP. Consider moving it, if it is found useful for other frontends.""" - def __init__(self, check_abort, download_size, tempfile_maker): + def __init__(self, download_size, tempfile_maker): PrefixingLogMixin.__init__(self, facility="tahoe.sftp") - if noisy: self.log(".__init__(%r, %r, %r)" % (check_abort, download_size, tempfile_maker), level=NOISY) - self.check_abort = check_abort + if noisy: self.log(".__init__(%r, %r)" % (download_size, tempfile_maker), level=NOISY) self.download_size = download_size self.current_size = download_size self.f = tempfile_maker() @@ -389,9 +388,6 @@ class OverwriteableFileConsumer(PrefixingLogMixin): if noisy: self.log(".write()" % (len(data),), level=NOISY) if self.is_closed: return - if self.check_abort(): - self.close() - return if self.downloaded >= self.download_size: return @@ -631,13 +627,12 @@ class GeneralSFTPFile(PrefixingLogMixin): file handle, and requests to my OverwriteableFileConsumer. This queue is implemented by the callback chain of self.async.""" - def __init__(self, close_notify, check_abort, flags, convergence, parent=None, childname=None, filenode=None, metadata=None): + def __init__(self, close_notify, flags, convergence, parent=None, childname=None, filenode=None, metadata=None): PrefixingLogMixin.__init__(self, facility="tahoe.sftp") - if noisy: self.log(".__init__(%r, %r, %r, , parent=%r, childname=%r, filenode=%r, metadata=%r)" % - (close_notify, check_abort, flags, parent, childname, filenode, metadata), level=NOISY) + if noisy: self.log(".__init__(%r, %r, , parent=%r, childname=%r, filenode=%r, metadata=%r)" % + (close_notify, flags, parent, childname, filenode, metadata), level=NOISY) self.close_notify = close_notify - self.check_abort = check_abort self.flags = flags self.convergence = convergence self.parent = parent @@ -648,6 +643,7 @@ class GeneralSFTPFile(PrefixingLogMixin): # Creating or truncating the file is a change, but if FXF_EXCL is set, a zero-length file has already been created. self.has_changed = (flags & (FXF_CREAT | FXF_TRUNC)) and not (flags & FXF_EXCL) self.closed = False + self.removed = False # self.consumer should only be relied on in callbacks for self.async, since it might # not be set before then. @@ -656,7 +652,7 @@ class GeneralSFTPFile(PrefixingLogMixin): if (flags & FXF_TRUNC) or not filenode: # We're either truncating or creating the file, so we don't need the old contents. - self.consumer = OverwriteableFileConsumer(self.check_abort, 0, tempfile_maker) + self.consumer = OverwriteableFileConsumer(0, tempfile_maker) self.consumer.finish() else: assert IFileNode.providedBy(filenode), filenode @@ -665,7 +661,7 @@ class GeneralSFTPFile(PrefixingLogMixin): if filenode.is_mutable(): self.async.addCallback(lambda ign: filenode.download_best_version()) def _downloaded(data): - self.consumer = OverwriteableFileConsumer(self.check_abort, len(data), tempfile_maker) + self.consumer = OverwriteableFileConsumer(len(data), tempfile_maker) self.consumer.write(data) self.consumer.finish() return None @@ -673,7 +669,7 @@ class GeneralSFTPFile(PrefixingLogMixin): else: download_size = filenode.get_size() assert download_size is not None, "download_size is None" - self.consumer = OverwriteableFileConsumer(self.check_abort, download_size, tempfile_maker) + self.consumer = OverwriteableFileConsumer(download_size, tempfile_maker) def _read(ign): if noisy: self.log("_read immutable", level=NOISY) filenode.read(self.consumer, 0, None) @@ -687,6 +683,11 @@ class GeneralSFTPFile(PrefixingLogMixin): self.parent = new_parent self.childname = new_childname + def remove(self): + self.log(".remove()", level=OPERATIONAL) + + self.removed = True + def readChunk(self, offset, length): request = ".readChunk(%r, %r)" % (offset, length) self.log(request, level=OPERATIONAL) @@ -763,7 +764,7 @@ class GeneralSFTPFile(PrefixingLogMixin): def _close(ign): d2 = defer.succeed(None) - if self.has_changed: + if self.has_changed and not self.removed: d2.addCallback(lambda ign: self.consumer.when_done()) if self.filenode and self.filenode.is_mutable(): d2.addCallback(lambda ign: self.consumer.get_current_size()) @@ -785,6 +786,13 @@ class GeneralSFTPFile(PrefixingLogMixin): def _closed(res): self.close_notify(self.parent, self.childname, self) + + # It is possible for there to be a race between adding the file and removing it. + if self.removed: + self.log("oops, we added %r but must now remove it" % (self.childname,), level=OPERATIONAL) + d2 = self.parent.delete(self.childname) + d2.addBoth(lambda ign: res) + return d2 return res d.addBoth(_closed) d.addBoth(_convert_error, request) @@ -878,7 +886,6 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): self._root = rootnode self._username = username self._convergence = client.convergence - self._logged_out = False self._open_files = {} # files created by this user handler and still open def gotVersion(self, otherVersion, extData): @@ -904,20 +911,36 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): else: all_open_files[direntry] = (files_to_add, time()) - def _remove_open_files(self, direntry, files_to_remove): - if direntry and not self._logged_out: - assert direntry in self._open_files, (direntry, self._open_files) - assert direntry in all_open_files, (direntry, all_open_files) - + def _remove_any_open_files(self, direntry): + removed = False + if direntry in self._open_files: + for f in self._open_files[direntry]: + f.remove() + del self._open_files[direntry] + removed = True + + if direntry in all_open_files: + (files, opentime) = all_open_files[direntry] + for f in files: + f.remove() + del all_open_files[direntry] + removed = True + + return removed + + def _close_notify(self, parent, childname, file_to_remove): + direntry = self._direntry_for(parent, childname) + if direntry in self._open_files: old_files = self._open_files[direntry] - new_files = [f for f in old_files if f not in files_to_remove] + new_files = [f for f in old_files if f is not file_to_remove] if len(new_files) > 0: self._open_files[direntry] = new_files else: del self._open_files[direntry] + if direntry in all_open_files: (all_old_files, opentime) = all_open_files[direntry] - all_new_files = [f for f in all_old_files if f not in files_to_remove] + all_new_files = [f for f in all_old_files if f is not file_to_remove] if len(all_new_files) > 0: all_open_files[direntry] = (all_new_files, opentime) else: @@ -950,16 +973,12 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): return None def logout(self): - if not self._logged_out: - self._logged_out = True - for (direntry, files_at_direntry) in enumerate(self._open_files): - self._remove_open_files(direntry, files_at_direntry) - - def _check_abort(self): - return self._logged_out + self.log(".logout()", level=OPERATIONAL) - def _close_notify(self, parent, childname, f): - self._remove_open_files(self._direntry_for(parent, childname), [f]) + for (direntry, files_at_direntry) in enumerate(self._open_files): + for f in files_at_direntry: + f.remove() + f.close() def _make_file(self, flags, parent=None, childname=None, filenode=None, metadata=None): if noisy: self.log("._make_file(%r = %r, parent=%r, childname=%r, filenode=%r, metadata=%r" % @@ -975,7 +994,7 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): if writing: direntry = self._direntry_for(parent, childname) - file = GeneralSFTPFile(self._close_notify, self._check_abort, flags, self._convergence, + file = GeneralSFTPFile(self._close_notify, flags, self._convergence, parent=parent, childname=childname, filenode=filenode, metadata=metadata) self._add_open_files(direntry, [file]) return file @@ -1247,7 +1266,9 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): # might not be enforced correctly if the type has just changed. if childname is None: - raise SFTPError(FX_NO_SUCH_FILE, "cannot delete an object specified by URI") + raise SFTPError(FX_NO_SUCH_FILE, "cannot remove an object specified by URI") + + removed = self._remove_any_open_files(self._direntry_for(parent, childname)) d2 = parent.get(childname) def _got_child(child): @@ -1257,7 +1278,13 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): if must_be_file and IDirectoryNode.providedBy(child): raise SFTPError(FX_PERMISSION_DENIED, "rmfile called on a directory") return parent.delete(childname) - d2.addCallback(_got_child) + def _no_child(err): + if removed and err.check(NoSuchChildError): + # suppress NoSuchChildError if an open file was removed + return None + else: + return err + d2.addCallbacks(_got_child, _no_child) return d2 d.addCallback(_got_parent) return d @@ -1362,7 +1389,7 @@ class SFTPUserHandler(ConchUser, PrefixingLogMixin): if "size" in attrs: # this would require us to download and re-upload the truncated/extended # file contents - def _unsupported(): raise SFTPError(FX_OP_UNSUPPORTED, "setAttrs wth size attribute") + def _unsupported(): raise SFTPError(FX_OP_UNSUPPORTED, "setAttrs wth size attribute unsupported") return defer.execute(_unsupported) return defer.succeed(None) diff --git a/src/allmydata/test/test_sftp.py b/src/allmydata/test/test_sftp.py index ca21c3b5..b3baef2f 100644 --- a/src/allmydata/test/test_sftp.py +++ b/src/allmydata/test/test_sftp.py @@ -892,7 +892,7 @@ class Handler(GridTestMixin, ShouldFailMixin, unittest.TestCase): # removing a link to an open file should not prevent it from being read d.addCallback(lambda ign: self.handler.openFile("small", sftp.FXF_READ, {})) def _remove_and_read_small(rf): - d2= self.handler.removeFile("small") + d2 = self.handler.removeFile("small") d2.addCallback(lambda ign: self.shouldFail(NoSuchChildError, "removeFile small", "small", self.root.get, u"small")) @@ -902,6 +902,40 @@ class Handler(GridTestMixin, ShouldFailMixin, unittest.TestCase): return d2 d.addCallback(_remove_and_read_small) + # removing a link to a created file should prevent it from being created + d.addCallback(lambda ign: self.handler.openFile("tempfile", sftp.FXF_READ | sftp.FXF_WRITE | + sftp.FXF_CREAT, {})) + def _write_remove(rwf): + d2 = rwf.writeChunk(0, "0123456789") + d2.addCallback(lambda ign: self.handler.removeFile("tempfile")) + d2.addCallback(lambda ign: rwf.readChunk(0, 10)) + d2.addCallback(lambda data: self.failUnlessReallyEqual(data, "0123456789")) + d2.addCallback(lambda ign: rwf.close()) + return d2 + d.addCallback(_write_remove) + d.addCallback(lambda ign: + self.shouldFail(NoSuchChildError, "removeFile tempfile", "tempfile", + self.root.get, u"tempfile")) + + # ... even if the link is renamed while open + d.addCallback(lambda ign: self.handler.openFile("tempfile2", sftp.FXF_READ | sftp.FXF_WRITE | + sftp.FXF_CREAT, {})) + def _write_rename_remove(rwf): + d2 = rwf.writeChunk(0, "0123456789") + d2.addCallback(lambda ign: self.handler.renameFile("tempfile2", "tempfile3")) + d2.addCallback(lambda ign: self.handler.removeFile("tempfile3")) + d2.addCallback(lambda ign: rwf.readChunk(0, 10)) + d2.addCallback(lambda data: self.failUnlessReallyEqual(data, "0123456789")) + d2.addCallback(lambda ign: rwf.close()) + return d2 + d.addCallback(_write_rename_remove) + d.addCallback(lambda ign: + self.shouldFail(NoSuchChildError, "removeFile tempfile2", "tempfile2", + self.root.get, u"tempfile2")) + d.addCallback(lambda ign: + self.shouldFail(NoSuchChildError, "removeFile tempfile3", "tempfile3", + self.root.get, u"tempfile3")) + return d def test_removeDirectory(self):