Added ability to disable fallocate

Change-Id: Id8872c581ed23378a8e14cbf3bf049b5c0d21577

doc/source/development_saio.rst

@@ -331,6 +331,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/1/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6012
         user = <your-user-name>
         log_facility = LOG_LOCAL2
@@ -357,6 +358,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/2/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6022
         user = <your-user-name>
         log_facility = LOG_LOCAL3
@@ -383,6 +385,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/3/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6032
         user = <your-user-name>
         log_facility = LOG_LOCAL4
@@ -409,6 +412,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/4/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6042
         user = <your-user-name>
         log_facility = LOG_LOCAL5
@@ -435,6 +439,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/1/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6011
         user = <your-user-name>
         log_facility = LOG_LOCAL2
@@ -463,6 +468,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/2/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6021
         user = <your-user-name>
         log_facility = LOG_LOCAL3
@@ -491,6 +497,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/3/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6031
         user = <your-user-name>
         log_facility = LOG_LOCAL4
@@ -519,6 +526,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/4/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6041
         user = <your-user-name>
         log_facility = LOG_LOCAL5
@@ -548,6 +556,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/1/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6010
         user = <your-user-name>
         log_facility = LOG_LOCAL2
@@ -574,6 +583,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/2/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6020
         user = <your-user-name>
         log_facility = LOG_LOCAL3
@@ -600,6 +610,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/3/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6030
         user = <your-user-name>
         log_facility = LOG_LOCAL4
@@ -626,6 +637,7 @@ Sample configuration files are provided with all defaults in line-by-line commen
         [DEFAULT]
         devices = /srv/4/node
         mount_check = false
+        disable_fallocate = true
         bind_port = 6040
         user = <your-user-name>
         log_facility = LOG_LOCAL5

etc/account-server.conf-sample

@@ -7,6 +7,7 @@
 # swift_dir = /etc/swift
 # devices = /srv/node
 # mount_check = true
+# disable_fallocate = false
 # You can specify default log routing here if you want:
 # log_name = swift
 # log_facility = LOG_LOCAL0

etc/container-server.conf-sample

@@ -7,6 +7,7 @@
 # swift_dir = /etc/swift
 # devices = /srv/node
 # mount_check = true
+# disable_fallocate = false
 # This is a comma separated list of hosts allowed in the X-Container-Sync-To
 # field for containers.
 # allowed_sync_hosts = 127.0.0.1

etc/object-server.conf-sample

@@ -7,6 +7,7 @@
 # swift_dir = /etc/swift
 # devices = /srv/node
 # mount_check = true
+# disable_fallocate = false
 # expiring_objects_container_divisor = 86400
 # You can specify default log routing here if you want:
 # log_name = swift

swift/common/daemon.py

@@ -84,6 +84,11 @@ def run_daemon(klass, conf_file, section_name='', once=False, **kwargs):
     else:
         logger = utils.get_logger(conf, conf.get('log_name', section_name),
            log_to_console=kwargs.pop('verbose', False), log_route=section_name)
+
+    # disable fallocate if desired
+    if conf.get('disable_fallocate', 'no').lower() in utils.TRUE_VALUES:
+        utils.disable_fallocate()
+
     try:
         klass(conf).run(once=once, **kwargs)
     except KeyboardInterrupt:

swift/common/utils.py

@@ -126,7 +126,11 @@ def get_param(req, name, default=None):
 
 class FallocateWrapper(object):
 
-    def __init__(self):
+    def __init__(self, noop=False):
+        if noop:
+            self.func_name = 'posix_fallocate'
+            self.fallocate = noop_libc_function
+            return
         ## fallocate is prefered because we need the on-disk size to match
         ## the allocated size. Older versions of sqlite require that the
         ## two sizes match. However, fallocate is Linux only.
@@ -147,6 +151,11 @@ class FallocateWrapper(object):
         return self.fallocate(*args[self.func_name])
 
 
+def disable_fallocate():
+    global _sys_fallocate
+    _sys_fallocate = FallocateWrapper(noop=True)
+
+
 def fallocate(fd, size):
     """
     Pre-allocate disk space for a file.

swift/common/wsgi.py

@@ -30,8 +30,9 @@ from eventlet.green import socket, ssl
 from webob import Request
 from urllib import unquote
 
-from swift.common.utils import get_logger, drop_privileges, \
+from swift.common.utils import capture_stdio, disable_fallocate, \
-    validate_configuration, capture_stdio, NullLogger
+    drop_privileges, get_logger, NullLogger, TRUE_VALUES, \
+    validate_configuration
 
 
 def monkey_patch_mimetools():
@@ -124,6 +125,10 @@ def run_wsgi(conf_file, app_section, *args, **kwargs):
         logger = get_logger(conf, log_name,
             log_to_console=kwargs.pop('verbose', False), log_route='wsgi')
 
+    # disable fallocate if desired
+    if conf.get('disable_fallocate', 'no').lower() in TRUE_VALUES:
+        disable_fallocate()
+
     # bind to address and port
     sock = get_socket(conf, default_port=kwargs.get('default_port', 8080))
     # remaining tasks should not require elevated privileges