diff options
Diffstat (limited to '')
| -rw-r--r-- | man2/flock.2 | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/man2/flock.2 b/man2/flock.2 index 5f2917f..c2c93ca 100644 --- a/man2/flock.2 +++ b/man2/flock.2 @@ -12,7 +12,7 @@ .\" FIXME Maybe document LOCK_MAND, LOCK_RW, LOCK_READ, LOCK_WRITE .\" which only have effect for SAMBA. .\" -.TH flock 2 2023-03-30 "Linux man-pages 6.05.01" +.TH flock 2 2024-03-03 "Linux man-pages 6.7" .SH NAME flock \- apply or remove an advisory lock on an open file .SH LIBRARY @@ -21,14 +21,14 @@ Standard C library .SH SYNOPSIS .nf .B #include <sys/file.h> -.PP -.BI "int flock(int " fd ", int " operation ); +.P +.BI "int flock(int " fd ", int " op ); .fi .SH DESCRIPTION Apply or remove an advisory lock on the open file specified by .IR fd . The argument -.I operation +.I op is one of the following: .RS 4 .TP 9 @@ -45,7 +45,7 @@ file at a given time. .B LOCK_UN Remove an existing lock held by this process. .RE -.PP +.P A call to .BR flock () may block if an incompatible lock is held by another process. @@ -53,9 +53,9 @@ To make a nonblocking request, include .B LOCK_NB (by ORing) with any of the above operations. -.PP +.P A single file may not simultaneously have both shared and exclusive locks. -.PP +.P Locks created by .BR flock () are associated with an open file description (see @@ -70,7 +70,7 @@ Furthermore, the lock is released either by an explicit .B LOCK_UN operation on any of these duplicate file descriptors, or when all such file descriptors have been closed. -.PP +.P If a process uses .BR open (2) (or similar) to obtain more than one file descriptor for the same file, @@ -79,19 +79,19 @@ these file descriptors are treated independently by An attempt to lock the file using one of these file descriptors may be denied by a lock that the calling process has already placed via another file descriptor. -.PP +.P A process may hold only one type of lock (shared or exclusive) on a file. Subsequent .BR flock () calls on an already locked file will convert an existing lock to the new lock mode. -.PP +.P Locks created by .BR flock () are preserved across an .BR execve (2). -.PP +.P A shared or exclusive lock can be placed on a file regardless of the mode in which the file was opened. .SH RETURN VALUE @@ -111,7 +111,7 @@ delivery of a signal caught by a handler; see .BR signal (7). .TP .B EINVAL -.I operation +.I op is invalid. .TP .B ENOLCK @@ -149,7 +149,7 @@ Up to Linux 5.4, .BR flock () is not propagated over SMB. A file with such locks will not appear locked for remote clients. -.PP +.P Since Linux 5.5, .BR flock () locks are emulated with SMB byte-range locks on the entire file. @@ -164,7 +164,7 @@ any IO on a locked file will always fail with when done from a separate file descriptor. This difference originates from the design of locks in the SMB protocol, which provides mandatory locking semantics. -.PP +.P Remote and mandatory locking semantics may vary with SMB protocol, mount options and server type. See @@ -191,7 +191,7 @@ Instead, one could use byte-range locking, which does work over NFS, given a sufficiently recent version of Linux and a server which supports locking. -.PP +.P Since Linux 2.6.12, NFS clients support .BR flock () locks by emulating them as @@ -206,7 +206,7 @@ locks interact with one another over NFS. It also means that in order to place an exclusive lock, the file must be opened for writing. -.PP +.P Since Linux 2.6.37, .\" commit 5eebde23223aeb0ad2d9e3be6590ff8bbfab0fc2 the kernel supports a compatibility mode that allows @@ -224,7 +224,7 @@ places advisory locks only; given suitable permissions on a file, a process is free to ignore the use of .BR flock () and perform I/O on the file. -.PP +.P .BR flock () and .BR fcntl (2) @@ -237,7 +237,7 @@ using the semantics of .BR flock () will be different from those described in this manual page. -.PP +.P Converting a lock (shared to exclusive, or vice versa) is not guaranteed to be atomic: the existing lock is first removed, and then a new lock is established. @@ -260,7 +260,7 @@ and occurs on many other implementations.) .BR open (2), .BR lockf (3), .BR lslocks (8) -.PP +.P .I Documentation/filesystems/locks.txt in the Linux kernel source tree .RI ( Documentation/locks.txt |