/* Free a buffered I/O handle */
int
stream_close(StreamHandle_t * streamP, int reallyClose)
{
ssize_t rc;
int retval = 0;
osi_Assert(streamP != NULL);
if (streamP->str_direction == STREAM_DIRECTION_WRITE
&& streamP->str_bufoff > 0) {
rc = OS_PWRITE(streamP->str_fd, streamP->str_buffer,
streamP->str_bufoff, streamP->str_fdoff);
if (rc < 0) {
retval = -1;
} else {
streamP->str_fdoff += rc;
}
}
if (reallyClose) {
rc = OS_CLOSE(streamP->str_fd);
if (rc < 0) {
retval = -1;
}
}
streamP->str_fd = INVALID_FD;
IH_LOCK;
DLL_INSERT_TAIL(streamP, streamAvailHead, streamAvailTail,
str_next, str_prev);
IH_UNLOCK;
return retval;
}
/*
* Actually close the file descriptor handle and return it to
* the free list.
*/
int
fd_reallyclose(FdHandle_t * fdP)
{
FD_t closeFd;
IHandle_t *ihP;
if (!fdP)
return 0;
IH_LOCK;
osi_Assert(ih_Inited);
osi_Assert(fdInUseCount > 0);
osi_Assert(fdP->fd_status == FD_HANDLE_INUSE ||
fdP->fd_status == FD_HANDLE_CLOSING);
ihP = fdP->fd_ih;
closeFd = fdP->fd_fd;
fdP->fd_refcnt--;
if (fdP->fd_refcnt == 0) {
DLL_DELETE(fdP, ihP->ih_fdhead, ihP->ih_fdtail, fd_ihnext, fd_ihprev);
DLL_INSERT_TAIL(fdP, fdAvailHead, fdAvailTail, fd_next, fd_prev);
fdP->fd_status = FD_HANDLE_AVAIL;
fdP->fd_refcnt = 0;
fdP->fd_ih = NULL;
fdP->fd_fd = INVALID_FD;
}
/* All the file descriptor handles have been closed; reset
* the IH_REALLY_CLOSED flag indicating that ih_reallyclose
* has completed its job.
*/
if (!ihP->ih_fdhead) {
ihP->ih_flags &= ~IH_REALLY_CLOSED;
}
if (fdP->fd_refcnt == 0) {
IH_UNLOCK;
OS_CLOSE(closeFd);
IH_LOCK;
fdInUseCount -= 1;
}
/* If this is not the only reference to the Inode then we can decrement
* the reference count, otherwise we need to call ih_release. */
if (ihP->ih_refcnt > 1)
ihP->ih_refcnt--;
else
_ih_release_r(ihP);
IH_UNLOCK;
return 0;
}
/* Close all unused file descriptors associated with the inode
* handle. Called with IH_LOCK held. May drop and reacquire
* IH_LOCK. Sets the IH_REALLY_CLOSED flag in the inode handle
* if it fails to close all file handles.
*/
static int
ih_fdclose(IHandle_t * ihP)
{
int closeCount, closedAll;
FdHandle_t *fdP, *head, *tail, *next;
osi_Assert(ihP->ih_refcnt > 0);
closedAll = 1;
DLL_INIT_LIST(head, tail);
ihP->ih_flags &= ~IH_REALLY_CLOSED;
/*
* Remove the file descriptors for this Inode from the LRU queue
* and the IHandle queue and put them on a temporary queue so we
* can drop the lock before we close the files.
*/
for (fdP = ihP->ih_fdhead; fdP != NULL; fdP = next) {
next = fdP->fd_ihnext;
osi_Assert(fdP->fd_ih == ihP);
osi_Assert(fdP->fd_status == FD_HANDLE_OPEN
|| fdP->fd_status == FD_HANDLE_INUSE
|| fdP->fd_status == FD_HANDLE_CLOSING);
if (fdP->fd_status == FD_HANDLE_OPEN) {
/* Note that FdHandle_t's do not count against the parent
* IHandle_t ref count when they are FD_HANDLE_OPEN. So, we don't
* need to dec the parent IHandle_t ref count for each one we pull
* off here. */
DLL_DELETE(fdP, ihP->ih_fdhead, ihP->ih_fdtail, fd_ihnext,
fd_ihprev);
DLL_DELETE(fdP, fdLruHead, fdLruTail, fd_next, fd_prev);
DLL_INSERT_TAIL(fdP, head, tail, fd_next, fd_prev);
} else {
closedAll = 0;
fdP->fd_status = FD_HANDLE_CLOSING;
ihP->ih_flags |= IH_REALLY_CLOSED;
}
}
/* If the ihandle reference count is 1, we should have
* closed all file descriptors.
*/
if (ihP->ih_refcnt == 1 || closedAll) {
osi_Assert(closedAll);
osi_Assert(!ihP->ih_fdhead);
osi_Assert(!ihP->ih_fdtail);
}
if (head == NULL) {
return 0; /* No file descriptors closed */
}
IH_UNLOCK;
/*
* Close the file descriptors
*/
closeCount = 0;
for (fdP = head; fdP != NULL; fdP = fdP->fd_next) {
OS_CLOSE(fdP->fd_fd);
fdP->fd_status = FD_HANDLE_AVAIL;
fdP->fd_refcnt = 0;
fdP->fd_fd = INVALID_FD;
fdP->fd_ih = NULL;
closeCount++;
}
IH_LOCK;
osi_Assert(fdInUseCount >= closeCount);
fdInUseCount -= closeCount;
/*
* Append the temporary queue to the list of available descriptors
*/
if (fdAvailHead == NULL) {
fdAvailHead = head;
fdAvailTail = tail;
} else {
fdAvailTail->fd_next = head;
head->fd_prev = fdAvailTail;
fdAvailTail = tail;
}
return 0;
}
/*
* 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;
}
/**
* handle a single vol header as part of VWalkVolumeHeaders.
*
* @param[in] dp disk partition
* @param[in] volfunc function to call when a vol header is successfully read
* @param[in] name full path name to the .vol header
* @param[out] hdr header data read in from the .vol header
* @param[in] locked 1 if the partition headers are locked, 0 otherwise
* @param[in] rock the rock to pass to volfunc
*
* @return operation status
* @retval 0 success
* @retval -1 fatal error, stop scanning
* @retval 1 failed to read header
* @retval 2 volfunc callback indicated error after header read
*/
static int
_VHandleVolumeHeader(struct DiskPartition64 *dp, VWalkVolFunc volfunc,
const char *name, struct VolumeDiskHeader *hdr,
int locked, void *rock)
{
int error = 0;
FD_t fd;
if ((fd = OS_OPEN(name, O_RDONLY, 0)) == INVALID_FD
|| OS_READ(fd, hdr, sizeof(*hdr))
!= sizeof(*hdr)
|| hdr->stamp.magic != VOLUMEHEADERMAGIC) {
error = 1;
}
if (fd != INVALID_FD) {
OS_CLOSE(fd);
}
#ifdef AFSFS_DEMAND_ATTACH_FS
if (locked) {
VPartHeaderUnlock(dp);
}
#endif /* AFS_DEMAND_ATTACH_FS */
if (!error && volfunc) {
/* the volume header seems fine; call the caller-supplied
* 'we-found-a-volume-header' function */
int last = 1;
#ifdef AFS_DEMAND_ATTACH_FS
if (!locked) {
last = 0;
}
#endif /* AFS_DEMAND_ATTACH_FS */
error = (*volfunc) (dp, name, hdr, last, rock);
if (error < 0) {
return -1;
}
if (error) {
error = 2;
}
}
#ifdef AFS_DEMAND_ATTACH_FS
if (error && !locked) {
int code;
/* retry reading the volume header under the partition
* header lock, just to be safe and ensure we're not
* racing something rewriting the vol header */
code = VPartHeaderLock(dp, WRITE_LOCK);
if (code) {
Log("Error acquiring partition write lock when "
"looking at header %s\n", name);
return -1;
}
return _VHandleVolumeHeader(dp, volfunc, name, hdr, 1, rock);
}
#endif /* AFS_DEMAND_ATTACH_FS */
return error;
}
/*
* 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;
}
