Lines Matching full:mandatory

1 	Mandatory File Locking For The Linux Operating System
8 0. Why you should avoid mandatory locking
14 	- The write system call checks for a mandatory lock only once
17 	  A process may then see file data change even while a mandatory
27 1. What is  mandatory locking?
30 Mandatory locking is kernel enforced file locking, as opposed to the more usual
46 with a "mandatory" locking scheme, whereby the operating system kernel would
51 The System V mandatory locking scheme was intended to have as little impact as
53 as candidates for mandatory locking, and using the existing fcntl()/lockf()
59 to entire files, so the mandatory locking rules also have byte level
62 Note 2: POSIX.1 does not specify any scheme for mandatory locking, despite
63 borrowing the fcntl() locking scheme from System V. The mandatory locking
66 2. Marking a file for mandatory locking
69 A file is marked as a candidate for mandatory locking by setting the group-id
76 modified to recognize the special case of a mandatory lock candidate and to
78 to run mandatory lock candidates with setgid privileges.
83 I have considered the implementations of mandatory locking available with
90 another process has outstanding mandatory locks. This is in direct
97 just mandatory locks. That would appear to contravene POSIX.1.
100 prevent mandatory locks from being applied to an mmap()'ed file, but  HP-UX
105 only from mandatory locks - that is what is currently implemented.
108 mandatory locks, so reads and writes to locked files always block when they
118 1. Mandatory locks can only be applied via the fcntl()/lockf() locking
120    locks using flock() never result in a mandatory lock.
122 2. If a process has locked a region of a file with a mandatory read lock, then
129 3. If a process has locked a region of a file with a mandatory write lock, all
135    any mandatory locks owned by other processes will be rejected with the
138 5. Attempts to apply a mandatory lock to a file that is memory mapped and
143    that has any mandatory locks in effect will be rejected with the error status
152 for the purposes of mandatory locking.
160 Note 3: I may have overlooked some system calls that need mandatory lock
167 Not even root can override a mandatory lock, so runaway processes can wreak
174 Mandatory locking is disabled on all filesystems by default, and must be
178 Since kernel v4.5, it is possible to disable mandatory locking