/*
* Get a file descriptor handle given an Inode handle
*/
FdHandle_t *
ih_open(IHandle_t * ihP)
{
FdHandle_t *fdP;
FD_t fd;
FD_t closeFd;
if (!ihP) /* XXX should log here in the fileserver */
return NULL;
IH_LOCK;
/* Do we already have an open file handle for this Inode? */
for (fdP = ihP->ih_fdtail; fdP != NULL; fdP = fdP->fd_ihprev) {
if (fdP->fd_status == FD_HANDLE_CLOSING) {
/* The handle was open when an IH_REALLYCLOSE was issued, so we
* cannot reuse it; it will be closed soon. */
continue;
}
#ifndef HAVE_PIO
/*
* If we don't have positional i/o, don't try to share fds, since
* we can't do so in a threadsafe way.
*/
if (fdP->fd_status == FD_HANDLE_INUSE) {
continue;
}
osi_Assert(fdP->fd_status == FD_HANDLE_OPEN);
#else /* HAVE_PIO */
osi_Assert(fdP->fd_status != FD_HANDLE_AVAIL);
#endif /* HAVE_PIO */
fdP->fd_refcnt++;
if (fdP->fd_status == FD_HANDLE_OPEN) {
fdP->fd_status = FD_HANDLE_INUSE;
DLL_DELETE(fdP, fdLruHead, fdLruTail, fd_next, fd_prev);
}
ihP->ih_refcnt++;
IH_UNLOCK;
return fdP;
}
/*
* Try to open the Inode, return NULL on error.
*/
fdInUseCount += 1;
IH_UNLOCK;
ih_open_retry:
fd = OS_IOPEN(ihP);
IH_LOCK;
if (fd == INVALID_FD && (errno != EMFILE || fdLruHead == NULL) ) {
fdInUseCount -= 1;
IH_UNLOCK;
return NULL;
}
/* fdCacheSize limits the size of the descriptor cache, but
* we permit the number of open files to exceed fdCacheSize.
* We only recycle open file descriptors when the number
* of open files reaches the size of the cache */
if ((fdInUseCount > fdCacheSize || fd == INVALID_FD) && fdLruHead != NULL) {
fdP = fdLruHead;
osi_Assert(fdP->fd_status == FD_HANDLE_OPEN);
DLL_DELETE(fdP, fdLruHead, fdLruTail, fd_next, fd_prev);
DLL_DELETE(fdP, fdP->fd_ih->ih_fdhead, fdP->fd_ih->ih_fdtail,
fd_ihnext, fd_ihprev);
closeFd = fdP->fd_fd;
if (fd == INVALID_FD) {
fdCacheSize--; /* reduce in order to not run into here too often */
DLL_INSERT_TAIL(fdP, fdAvailHead, fdAvailTail, fd_next, fd_prev);
fdP->fd_status = FD_HANDLE_AVAIL;
fdP->fd_ih = NULL;
fdP->fd_fd = INVALID_FD;
IH_UNLOCK;
OS_CLOSE(closeFd);
goto ih_open_retry;
}
} else {
if (fdAvailHead == NULL) {
fdHandleAllocateChunk();
}
fdP = fdAvailHead;
osi_Assert(fdP->fd_status == FD_HANDLE_AVAIL);
DLL_DELETE(fdP, fdAvailHead, fdAvailTail, fd_next, fd_prev);
closeFd = INVALID_FD;
}
fdP->fd_status = FD_HANDLE_INUSE;
fdP->fd_fd = fd;
fdP->fd_ih = ihP;
fdP->fd_refcnt++;
ihP->ih_refcnt++;
/* Add this handle to the Inode's list of open descriptors */
DLL_INSERT_TAIL(fdP, ihP->ih_fdhead, ihP->ih_fdtail, fd_ihnext,
fd_ihprev);
if (closeFd != INVALID_FD) {
IH_UNLOCK;
OS_CLOSE(closeFd);
IH_LOCK;
fdInUseCount -= 1;
}
IH_UNLOCK;
return fdP;
}
/*
* Get a file descriptor handle given an Inode handle
*/
FdHandle_t *
ih_open(IHandle_t * ihP)
{
FdHandle_t *fdP;
FD_t fd;
FD_t closeFd;
if (!ihP) /* XXX should log here in the fileserver */
return NULL;
IH_LOCK;
/* Do we already have an open file handle for this Inode? */
for (fdP = ihP->ih_fdtail; fdP != NULL; fdP = fdP->fd_ihprev) {
if (fdP->fd_status != FD_HANDLE_INUSE) {
assert(fdP->fd_status == FD_HANDLE_OPEN);
fdP->fd_status = FD_HANDLE_INUSE;
DLL_DELETE(fdP, fdLruHead, fdLruTail, fd_next, fd_prev);
ihP->ih_refcnt++;
IH_UNLOCK;
(void)FDH_SEEK(fdP, 0, SEEK_SET);
return fdP;
}
}
/*
* Try to open the Inode, return NULL on error.
*/
fdInUseCount += 1;
IH_UNLOCK;
ih_open_retry:
fd = OS_IOPEN(ihP);
IH_LOCK;
if (fd == INVALID_FD && (errno != EMFILE || fdLruHead == NULL) ) {
fdInUseCount -= 1;
IH_UNLOCK;
return NULL;
}
/* fdCacheSize limits the size of the descriptor cache, but
* we permit the number of open files to exceed fdCacheSize.
* We only recycle open file descriptors when the number
* of open files reaches the size of the cache */
if ((fdInUseCount > fdCacheSize || fd == INVALID_FD) && fdLruHead != NULL) {
fdP = fdLruHead;
assert(fdP->fd_status == FD_HANDLE_OPEN);
DLL_DELETE(fdP, fdLruHead, fdLruTail, fd_next, fd_prev);
DLL_DELETE(fdP, fdP->fd_ih->ih_fdhead, fdP->fd_ih->ih_fdtail,
fd_ihnext, fd_ihprev);
closeFd = fdP->fd_fd;
if (fd == INVALID_FD) {
fdCacheSize--; /* reduce in order to not run into here too often */
DLL_INSERT_TAIL(fdP, fdAvailHead, fdAvailTail, fd_next, fd_prev);
fdP->fd_status = FD_HANDLE_AVAIL;
fdP->fd_ih = NULL;
fdP->fd_fd = INVALID_FD;
IH_UNLOCK;
OS_CLOSE(closeFd);
goto ih_open_retry;
}
} else {
if (fdAvailHead == NULL) {
fdHandleAllocateChunk();
}
fdP = fdAvailHead;
assert(fdP->fd_status == FD_HANDLE_AVAIL);
DLL_DELETE(fdP, fdAvailHead, fdAvailTail, fd_next, fd_prev);
closeFd = INVALID_FD;
}
fdP->fd_status = FD_HANDLE_INUSE;
fdP->fd_fd = fd;
fdP->fd_ih = ihP;
ihP->ih_refcnt++;
/* Add this handle to the Inode's list of open descriptors */
DLL_INSERT_TAIL(fdP, ihP->ih_fdhead, ihP->ih_fdtail, fd_ihnext,
fd_ihprev);
if (closeFd != INVALID_FD) {
IH_UNLOCK;
OS_CLOSE(closeFd);
IH_LOCK;
fdInUseCount -= 1;
}
IH_UNLOCK;
return fdP;
}
