Hm. Your patch seems to do this:
change:
lock/unlock from current to eof
to:
seek 0
lock/unlock from (current=0) to eof
Which means you're potentially destroying the notion of "current" (I
don't know if that's important in AFS code or not, but it seems like,
at best, a bad idea ... and at worst, a potentially disastrous idea).
I would suggest:
save current to tmp
seek 0
lock/unlock from (current=0) to eof
seek tmp
On Sep 11, 2006, at 1:43 AM, Rainer Toebbicke wrote:
The namei interface uses file locking extensively, implemented using
lockf() on Solaris, AIX & HP-UX.
Unfortunately lockf() locks and unlocks from the *current position* to
whatever the argument says (end of file), moving the file pointer in
between becomes a problem for the subsequent unlock! The result is
that frequently locks aren't released, but replaced by partial locks
on the file data just moved over.
In consequence almost-deadlocks between fileserver and volserver
happen (although rarely), in particular on the "link count" file.
Together with the salvager which locks the partition a complete
deadlock can be provoked.
The attached patch forces lockf to lock/unlock from 0, more closely
emulating flock().
(Bcc'ed to openafs-bugs)
--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
=-=-=-=
Rainer Toebbicke
European Laboratory for Particle Physics(CERN) - Geneva, Switzerland
Phone: +41 22 767 8985 Fax: +41 22 767 7155
--- openafs/src/vol/namei_ops.c.xxxx 2006-09-08 12:54:04.000000000
+0200
+++ openafs/src/vol/namei_ops.c 2006-09-08 12:56:07.000000000 +0200
@@ -869,6 +869,7 @@
if (lockit) {
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
+ lseek(h->fd_fd, (off_t) 0, SEEK_SET);
if (lockf(h->fd_fd, F_LOCK, 0) < 0)
#else
if (flock(h->fd_fd, LOCK_EX) < 0)
@@ -888,7 +889,7 @@
bad_getLinkByte:
if (lockit)
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
- lockf(h->fd_fd, F_ULOCK, 0);
+ { lseek(h->fd_fd, (off_t) 0, SEEK_SET); lockf(h->fd_fd, F_ULOCK,
0); }
#else
flock(h->fd_fd, LOCK_UN);
#endif
@@ -913,6 +914,7 @@
/* Only one manipulates at a time. */
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
+ lseek(fdP->fd_fd, (off_t) 0, SEEK_SET);
if (lockf(fdP->fd_fd, F_LOCK, 0) < 0) {
#else
if (flock(fdP->fd_fd, LOCK_EX) < 0) {
@@ -953,6 +955,7 @@
}
FDH_SYNC(fdP);
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
+ lseek(fdP->fd_fd, (off_t) 0, SEEK_SET);
lockf(fdP->fd_fd, F_ULOCK, 0);
#else
flock(fdP->fd_fd, LOCK_UN);
@@ -962,6 +965,7 @@
badGetFreeTag:
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
+ lseek(fdP->fd_fd, (off_t) 0, SEEK_SET);
lockf(fdP->fd_fd, F_ULOCK, 0);
#else
flock(fdP->fd_fd, LOCK_UN);
@@ -989,6 +993,7 @@
if (!locked) {
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
+ lseek(fdP->fd_fd, (off_t) 0, SEEK_SET);
if (lockf(fdP->fd_fd, F_LOCK, 0) < 0) {
#else
if (flock(fdP->fd_fd, LOCK_EX) < 0) {
@@ -1032,6 +1037,7 @@
bad_SetLinkCount:
#if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) ||
defined(AFS_HPUX_ENV)
+ lseek(fdP->fd_fd, (off_t) 0, SEEK_SET);
lockf(fdP->fd_fd, F_ULOCK, 0);
#else
flock(fdP->fd_fd, LOCK_UN);
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