Revision c7e4b037
| b/lib/uidpool.py | ||
|---|---|---|
| 182 | 182 |
def _IsUidUsed(uid): |
| 183 | 183 |
"""Check if there is any process in the system running with the given user-id |
| 184 | 184 |
|
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@type uid: integer |
|
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@param uid: the user-id to be checked. |
|
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|
|
| 185 | 188 |
""" |
| 186 | 189 |
pgrep_command = [constants.PGREP, "-u", uid] |
| 187 | 190 |
result = utils.RunCmd(pgrep_command) |
| ... | ... | |
| 218 | 221 |
def GetUid(self): |
| 219 | 222 |
return self._uid |
| 220 | 223 |
|
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def __str__(self):
|
|
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def AsStr(self):
|
|
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return "%s" % self._uid |
| 223 | 226 |
|
| 224 | 227 |
|
| ... | ... | |
| 255 | 258 |
<stop the process> |
| 256 | 259 |
uidpool.ReleaseUid(uid) |
| 257 | 260 |
|
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@type all_uids: set of integers |
|
| 258 | 262 |
@param all_uids: a set containing all the user-ids in the user-id pool |
| 259 | 263 |
@return: a LockedUid object representing the unused uid. It's the caller's |
| 260 | 264 |
responsibility to unlock the uid once an instance is started with |
| ... | ... | |
| 269 | 273 |
|
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# Get list of currently used uids from the filesystem |
| 271 | 275 |
try: |
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taken_uids = set(os.listdir(constants.UIDPOOL_LOCKDIR)) |
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# Filter out spurious entries from the directory listing |
|
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taken_uids = all_uids.intersection(taken_uids) |
|
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taken_uids = set() |
|
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for taken_uid in os.listdir(constants.UIDPOOL_LOCKDIR): |
|
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try: |
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taken_uid = int(taken_uid) |
|
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except ValueError, err: |
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# Skip directory entries that can't be converted into an integer |
|
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continue |
|
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taken_uids.add(taken_uid) |
|
| 275 | 284 |
except OSError, err: |
| 276 | 285 |
raise errors.LockError("Failed to get list of used user-ids: %s" % err)
|
| 277 | 286 |
|
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# Filter out spurious entries from the directory listing |
|
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taken_uids = all_uids.intersection(taken_uids) |
|
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|
|
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# Remove the list of used uids from the list of all uids |
| 279 | 291 |
unused_uids = list(all_uids - taken_uids) |
| 280 | 292 |
if not unused_uids: |
| ... | ... | |
| 330 | 342 |
if isinstance(uid, LockedUid): |
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# Make sure we release the exclusive lock, if there is any |
| 332 | 344 |
uid.Unlock() |
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uid_filename = uid.AsStr() |
|
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else: |
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uid_filename = str(uid) |
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|
|
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try: |
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uid_path = utils.PathJoin(constants.UIDPOOL_LOCKDIR, str(uid))
|
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uid_path = utils.PathJoin(constants.UIDPOOL_LOCKDIR, uid_filename)
|
|
| 335 | 351 |
os.remove(uid_path) |
| 336 | 352 |
except OSError, err: |
| 337 | 353 |
raise errors.LockError("Failed to remove user-id lockfile"
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" for user-id %s: %s" % (uid, err)) |
|
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" for user-id %s: %s" % (uid_filename, err))
|
|
| 339 | 355 |
|
| 340 | 356 |
|
| 341 | 357 |
def ExecWithUnusedUid(fn, all_uids, *args, **kwargs): |
| ... | ... | |
| 344 | 360 |
This wrapper function provides a simple way to handle the requesting, |
| 345 | 361 |
unlocking and releasing a user-id. |
| 346 | 362 |
"fn" is called by passing a "uid" keyword argument that |
| 347 |
contains an unused user-id (as a string) selected from the set of user-ids
|
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contains an unused user-id (as an integer) selected from the set of user-ids
|
|
| 348 | 364 |
passed in all_uids. |
| 349 | 365 |
If there is an error while executing "fn", the user-id is returned |
| 350 | 366 |
to the pool. |
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@param fn: a callable |
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@param fn: a callable that accepts a keyword argument called "uid" |
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@type all_uids: a set of integers |
|
| 353 | 370 |
@param all_uids: a set containing all user-ids in the user-id pool |
| 354 | 371 |
|
| 355 | 372 |
""" |
| 356 | 373 |
uid = RequestUnusedUid(all_uids) |
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kwargs["uid"] = str(uid)
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kwargs["uid"] = uid.GetUid()
|
|
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try: |
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return_value = fn(*args, **kwargs) |
| 360 | 377 |
except: |
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