diff options
author | des <des@FreeBSD.org> | 2008-10-20 18:02:16 +0000 |
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committer | des <des@FreeBSD.org> | 2008-10-20 18:02:16 +0000 |
commit | fd059e9b04b42452a89985b02276be2265480dca (patch) | |
tree | 0584909d4e914795b737773d9f8a066576f4cb3c | |
parent | 9a22db9431ce7e5719c00e9a183d0d1c6cdce048 (diff) | |
download | FreeBSD-src-fd059e9b04b42452a89985b02276be2265480dca.zip FreeBSD-src-fd059e9b04b42452a89985b02276be2265480dca.tar.gz |
Reimplement flopen(3) using fcntl(2) locks instead of flock(2) locks.
-rw-r--r-- | lib/libutil/flopen.3 | 17 | ||||
-rw-r--r-- | lib/libutil/flopen.c | 12 |
2 files changed, 16 insertions, 13 deletions
diff --git a/lib/libutil/flopen.3 b/lib/libutil/flopen.3 index 97a48f1..fe54b76 100644 --- a/lib/libutil/flopen.3 +++ b/lib/libutil/flopen.3 @@ -46,12 +46,13 @@ The function opens or creates a file and acquires an exclusive lock on it. It is essentially equivalent with calling .Fn open -with the same parameters followed by -.Fn flock -with an -.Va operation -argument of -.Dv LOCK_EX , +with the same parameters followed by an +.Fn fcntl +.Dv F_SETLK +or +.Dv F_SETLKW +operation with lock type +.Dv F_WRLCK , except that .Fn flopen will attempt to detect and handle races that may occur between opening @@ -86,12 +87,12 @@ returns a valid file descriptor. Otherwise, it returns -1, and sets .Va errno as described in -.Xr flock 2 +.Xr fcntl 2 and .Xr open 2 . .Sh SEE ALSO .Xr errno 2 , -.Xr flock 2 , +.Xr fcntl 2 , .Xr open 2 .Sh HISTORY The diff --git a/lib/libutil/flopen.c b/lib/libutil/flopen.c index 23742f7..a5bf8c6 100644 --- a/lib/libutil/flopen.c +++ b/lib/libutil/flopen.c @@ -28,12 +28,12 @@ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); -#include <sys/file.h> #include <sys/stat.h> #include <errno.h> #include <fcntl.h> #include <stdarg.h> +#include <string.h> #include <unistd.h> #include <libutil.h> @@ -42,6 +42,7 @@ int flopen(const char *path, int flags, ...) { int fd, operation, serrno, trunc; + struct flock flock; struct stat sb, fsb; mode_t mode; @@ -58,9 +59,10 @@ flopen(const char *path, int flags, ...) va_end(ap); } - operation = LOCK_EX; - if (flags & O_NONBLOCK) - operation |= LOCK_NB; + memset(&flock, 0, sizeof flock); + flock.l_type = F_WRLCK; + flock.l_whence = SEEK_SET; + operation = (flags & O_NONBLOCK) ? F_SETLK : F_SETLKW; trunc = (flags & O_TRUNC); flags &= ~O_TRUNC; @@ -69,7 +71,7 @@ flopen(const char *path, int flags, ...) if ((fd = open(path, flags, mode)) == -1) /* non-existent or no access */ return (-1); - if (flock(fd, operation) == -1) { + if (fcntl(fd, operation, &flock) == -1) { /* unsupported or interrupted */ serrno = errno; close(fd); |