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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 1 of 6 RESEND v2] blktap3/sring: Headers required for compiling the shared ring
This patch series introduces the headers required for the shared ring library
to compile. The files are:
* io-optimize.h: imported from blktap2
* scheduler.h: imported from blktap2, contains definitions for the tapdisk
scheduler, the component that processes events, be it I/O requests or
control commands
* tapdisk.h: imported from blktap2, core header file that contains the
definition of the I/O request
* tapdisk-image.h: imported from blktap2, contains the definition of the
Virtual Disk Image (VDI).
* tapdisk-log.h: imported from blktap2, contains logging stuff
* tapdisk-queue.h: imported from blktap2, contains the tapdisk I/O request
and event queue.
* tapdisk-server.h: imported from blktap2
* tapdisk-stats.h: imported from blktap2.5, contains stats stuff
* tapdisk-utils.h: imported from blktap2.5, contains assorted utility
functions
* tapdisk-vbd.h: imported from blktap2, contains the definition of the
Virtual Block Device (VBD)
Also, the patch series contains the following blktap3-related changes:
* Update declaration of function tapdisk_image_open_chain as it now uses
the parent /path/to/file instead of the parent minor number.
* Update declaration of function tapdisk_server_get_vbd as it now uses
type:/path/to/file instead of the minor number.
Signed-off-by: Thanos Makatos <thanos.makatos@xxxxxxxxxx>
diff --git a/tools/blktap3/drivers/io-optimize.h
b/tools/blktap3/drivers/io-optimize.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/io-optimize.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef __IO_OPTIMIZE_H__
+#define __IO_OPTIMIZE_H__
+
+#include <libaio.h>
+
+struct opio;
+
+struct opio_list {
+ struct opio *head;
+ struct opio *tail;
+};
+
+struct opio {
+ char *buf;
+ unsigned long nbytes;
+ long long offset;
+ void *data;
+ struct iocb *iocb;
+ struct io_event event;
+ struct opio *head;
+ struct opio *next;
+ struct opio_list list;
+};
+
+struct opioctx {
+ int num_opios;
+ int free_opio_cnt;
+ struct opio *opios;
+ struct opio **free_opios;
+ struct iocb **iocb_queue;
+ struct io_event *event_queue;
+};
+
+int opio_init(struct opioctx *ctx, int num_iocbs);
+void opio_free(struct opioctx *ctx);
+int io_merge(struct opioctx *ctx, struct iocb **queue, int num);
+int io_split(struct opioctx *ctx, struct io_event *events, int num);
+int io_expand_iocbs(struct opioctx *ctx, struct iocb **queue, int idx, int
num);
+
+#endif
diff --git a/tools/blktap3/drivers/scheduler.h
b/tools/blktap3/drivers/scheduler.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/scheduler.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _SCHEDULER_H_
+#define _SCHEDULER_H_
+
+#include <sys/select.h>
+#include "blktap3.h"
+
+#define SCHEDULER_POLL_READ_FD 0x1
+#define SCHEDULER_POLL_WRITE_FD 0x2
+#define SCHEDULER_POLL_EXCEPT_FD 0x4
+#define SCHEDULER_POLL_TIMEOUT 0x8
+
+typedef int event_id_t;
+typedef void (*event_cb_t) (event_id_t id, char mode, void *private);
+
+typedef struct event {
+ char mode;
+ char dead;
+ char pending;
+ char masked;
+
+ event_id_t id;
+
+ int fd;
+ int timeout;
+ int deadline;
+
+ event_cb_t cb;
+ void *private;
+
+ /*
+ * for linked lists
+ */
+ TAILQ_ENTRY(event) entry;
+} event_t;
+
+TAILQ_HEAD(tqh_event, event);
+
+typedef struct scheduler {
+ fd_set read_fds;
+ fd_set write_fds;
+ fd_set except_fds;
+
+ struct tqh_event events;
+
+ int uuid;
+ int max_fd;
+ int timeout;
+ int max_timeout;
+ int depth;
+} scheduler_t;
+
+void scheduler_initialize(scheduler_t *);
+event_id_t scheduler_register_event(scheduler_t *, char mode,
+ int fd, int timeout,
+ event_cb_t cb, void *private);
+void scheduler_unregister_event(scheduler_t *, event_id_t);
+void scheduler_mask_event(scheduler_t *, event_id_t, int masked);
+void scheduler_set_max_timeout(scheduler_t *, int);
+int scheduler_wait_for_events(scheduler_t *);
+
+#endif
diff --git a/tools/blktap3/drivers/tapdisk-blktap.h
b/tools/blktap3/drivers/tapdisk-blktap.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-blktap.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2010, Citrix Systems, Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _TAPDISK_BLKTAP_H_
+#define _TAPDISK_BLKTAP_H_
+
+typedef struct td_blktap td_blktap_t;
+typedef struct td_blktap_req td_blktap_req_t;
+
+#include "blktap3.h"
+#include "tapdisk-vbd.h"
+
+#if 0
+struct td_blktap_stats {
+ struct {
+ unsigned long long in;
+ unsigned long long out;
+ } reqs;
+ struct {
+ unsigned long long in;
+ unsigned long long out;
+ } kicks;
+};
+#endif
+
+struct td_blktap {
+ int minor;
+ //td_vbd_t *vbd;
+
+#if 0
+ int fd;
+#endif
+
+#if 0
+ void *vma;
+ size_t vma_size;
+
+ struct blktap_sring *sring;
+ unsigned int req_cons;
+ unsigned int rsp_prod_pvt;
+#endif
+
+#if 0
+ int event_id;
+ void *vstart;
+
+ int n_reqs;
+ td_blktap_req_t *reqs;
+ int n_reqs_free;
+ td_blktap_req_t **reqs_free;
+#endif
+
+ //TAILQ_ENTRY(td_blktap) entry;
+
+ //struct td_blktap_stats stats;
+};
+
+#endif /* _TAPDISK_BLKTAP_H_ */
diff --git a/tools/blktap3/drivers/tapdisk-image.h
b/tools/blktap3/drivers/tapdisk-image.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-image.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _TAPDISK_IMAGE_H_
+#define _TAPDISK_IMAGE_H_
+
+#include "tapdisk.h"
+
+TAILQ_HEAD(tqh_td_image_handle, td_image_handle);
+
+struct td_image_handle {
+ int type;
+ char *name;
+
+ td_flag_t flags;
+
+ td_driver_t *driver;
+ td_disk_info_t info;
+
+ /*
+ * for linked lists
+ */
+ TAILQ_ENTRY(td_image_handle) entry;
+
+ /*
+ * Basic datapath statistics, in sectors read/written.
+ *
+ * hits: requests completed by this image.
+ * fail: requests completed with failure by this image.
+ *
+ * Not that we do not count e.g.
+ * miss: requests forwarded.
+ * total: requests processed by this image.
+ *
+ * This is because we'd have to compensate for restarts due to
+ * -EBUSY conditions. Those can be extrapolated by following
+ * the chain instead: sum(image[i].hits, i=0..) == vbd.secs;
+ */
+ struct {
+ td_sector_count_t hits;
+ td_sector_count_t fail;
+ } stats;
+};
+
+#define tapdisk_for_each_image(_image, _head) \
+ TAILQ_FOREACH(_image, _head, entry)
+
+#define tapdisk_for_each_image_safe(_image, _next, _head) \
+ TAILQ_FOREACH_SAFE(_image, _head, entry, _next)
+
+#define tapdisk_for_each_image_reverse(_image, _head) \
+ TAILQ_FOREACH_REVERSE(_image, _head, tqh_td_image_handle, entry)
+
+#define tapdisk_image_entry(_head) \
+ list_entry(_head, td_image_t, next)
+
+/**
+ * Opens an image.
+ *
+ * @param type the image type (DISK_TYPE_*)
+ * @param name TODO ?
+ * @param flags TODO ?
+ * @param _image output parameter that receives a handle to the opened image
+ * @returns 0 on success
+ */
+int tapdisk_image_open(const int type, const char *name, const int flags,
+ td_image_t ** _image);
+
+void tapdisk_image_close(td_image_t *, struct tqh_td_image_handle *);
+
+/**
+ * Opens the image chain.
+ *
+ * @param params type:/path/to/file
+ * @param flags
+ * @param prt_path parent /path/to/file (optional)
+ * @param head
+ */
+int tapdisk_image_open_chain(const char *params, int flags,
+ const char* prt_path, struct tqh_td_image_handle *head);
+
+/**
+ * Closes all the images.
+ */
+void tapdisk_image_close_chain(struct tqh_td_image_handle *);
+int tapdisk_image_validate_chain(struct tqh_td_image_handle *);
+
+td_image_t *tapdisk_image_allocate(const char *, int, td_flag_t);
+void tapdisk_image_free(td_image_t *, struct tqh_td_image_handle *head);
+
+int tapdisk_image_check_td_request(td_image_t *, td_request_t);
+int tapdisk_image_check_request(td_image_t *, struct td_vbd_request *);
+void tapdisk_image_stats(td_image_t *, td_stats_t *);
+
+#endif
diff --git a/tools/blktap3/drivers/tapdisk-log.h
b/tools/blktap3/drivers/tapdisk-log.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-log.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2009, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _TAPDISK_LOG_H_
+#define _TAPDISK_LOG_H_
+
+#define TLOG_WARN 0
+#define TLOG_INFO 1
+#define TLOG_DBG 2
+
+#define TLOG_DIR "/var/log/blktap"
+
+#include <stdarg.h>
+#include "blktap3.h"
+
+int tlog_open(const char *, int, int);
+void tlog_close(void);
+void tlog_precious(void);
+void tlog_vsyslog(int, const char *, va_list);
+void tlog_syslog(int, const char *, ...);
+
+#include <syslog.h>
+
+#define EPRINTF(_f, _a...) syslog(LOG_ERR, "%s:%d " _f, __FILE__, __LINE__, \
+ ##_a)
+#define DPRINTF(_f, _a...) syslog(LOG_INFO, "%s:%d "_f, __FILE__, __LINE__, \
+ ##_a)
+#define PERROR(_f, _a...) EPRINTF(_f ": %s", ##_a, strerror(errno))
+
+void __tlog_write(int, const char *, ...) __printf(2, 3);
+void __tlog_error(const char *fmt, ...) __printf(1, 2);
+
+#define tlog_write(_level, _f, _a...) \
+ __tlog_write(_level, "%s: " _f, __func__, ##_a)
+
+#define tlog_error(_err, _f, _a...) \
+ __tlog_error("ERROR: errno %d at %s: " _f, \
+ (int)_err, __func__, ##_a)
+
+#define tlog_drv_error(_drv, _err, _f, _a ...) do { \
+ if (tapdisk_driver_log_pass(_drv, __func__)) \
+ tlog_error(_err, _f, ##_a); \
+} while (0)
+
+#endif /* __TAPDISK_LOG_H__ */
diff --git a/tools/blktap3/drivers/tapdisk-queue.h
b/tools/blktap3/drivers/tapdisk-queue.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-queue.h
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef TAPDISK_QUEUE_H
+#define TAPDISK_QUEUE_H
+
+#include <libaio.h>
+
+#include "io-optimize.h"
+#include "scheduler.h"
+
+struct tiocb;
+struct tfilter;
+
+typedef void (*td_queue_callback_t)(void *arg, struct tiocb *, int err);
+
+
+struct tiocb {
+ td_queue_callback_t cb;
+ void *arg;
+
+ struct iocb iocb;
+ struct tiocb *next;
+};
+
+struct tlist {
+ struct tiocb *head;
+ struct tiocb *tail;
+};
+
+struct tqueue {
+ int size;
+
+ const struct tio *tio;
+ void *tio_data;
+
+ struct opioctx opioctx;
+
+ int queued;
+ struct iocb **iocbs;
+
+ /* number of iocbs pending in the aio layer */
+ int iocbs_pending;
+
+ /* number of tiocbs pending in the queue --
+ * this is likely to be larger than iocbs_pending
+ * due to request coalescing */
+ int tiocbs_pending;
+
+ /* iocbs may be deferred if the aio ring is full.
+ * tapdisk_queue_complete will ensure deferred
+ * iocbs are queued as slots become available. */
+ struct tlist deferred;
+ int tiocbs_deferred;
+
+ /* optional tapdisk filter */
+ struct tfilter *filter;
+
+ uint64_t deferrals;
+};
+
+struct tio {
+ const char *name;
+ size_t data_size;
+
+ int (*tio_setup) (struct tqueue *queue, int qlen);
+ void (*tio_destroy) (struct tqueue *queue);
+ int (*tio_submit) (struct tqueue *queue);
+};
+
+enum {
+ TIO_DRV_LIO = 1,
+ TIO_DRV_RWIO = 2,
+};
+
+/*
+ * Interface for request producer (i.e., tapdisk)
+ * NB: the following functions may cause additional tiocbs to be queued:
+ * - tapdisk_submit_tiocbs
+ * - tapdisk_cancel_tiocbs
+ * - tapdisk_complete_tiocbs
+ * The *_all_tiocbs variants will handle the first two cases;
+ * be sure to call submit after calling complete in the third case.
+ */
+#define tapdisk_queue_count(q) ((q)->queued)
+#define tapdisk_queue_empty(q) ((q)->queued == 0)
+#define tapdisk_queue_full(q) \
+ (((q)->tiocbs_pending + (q)->queued) >= (q)->size)
+int tapdisk_init_queue(struct tqueue *, int size, int drv, struct tfilter *);
+void tapdisk_free_queue(struct tqueue *);
+void tapdisk_debug_queue(struct tqueue *);
+void tapdisk_queue_tiocb(struct tqueue *, struct tiocb *);
+int tapdisk_submit_tiocbs(struct tqueue *);
+int tapdisk_submit_all_tiocbs(struct tqueue *);
+int tapdisk_cancel_tiocbs(struct tqueue *);
+int tapdisk_cancel_all_tiocbs(struct tqueue *);
+void tapdisk_prep_tiocb(struct tiocb *, int, int, char *, size_t,
+ long long, td_queue_callback_t, void *);
+
+#endif
diff --git a/tools/blktap3/drivers/tapdisk-server.h
b/tools/blktap3/drivers/tapdisk-server.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-server.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _TAPDISK_SERVER_H_
+#define _TAPDISK_SERVER_H_
+
+#include "tapdisk-vbd.h"
+#include "tapdisk-queue.h"
+
+struct tap_disk *tapdisk_server_find_driver_interface(int);
+
+td_image_t *tapdisk_server_get_shared_image(td_image_t *);
+
+struct tqh_td_vbd_handle *tapdisk_server_get_all_vbds(void);
+
+/**
+ * Returns the VBD that corresponds to the specified type:/path/to/file.
+ * Returns NULL if such a VBD does not exist.
+ */
+td_vbd_t *tapdisk_server_get_vbd(const char *params);
+
+/**
+ * Adds the VBD to end of the list of VBDs.
+ */
+void tapdisk_server_add_vbd(td_vbd_t *);
+
+/**
+ * Removes the VBDs from the list of VBDs.
+ */
+void tapdisk_server_remove_vbd(td_vbd_t *);
+
+void tapdisk_server_queue_tiocb(struct tiocb *);
+
+void tapdisk_server_check_state(void);
+
+event_id_t tapdisk_server_register_event(char, int, int, event_cb_t, void *);
+void tapdisk_server_unregister_event(event_id_t);
+void tapdisk_server_mask_event(event_id_t, int);
+void tapdisk_server_set_max_timeout(int);
+
+int tapdisk_server_init(void);
+int tapdisk_server_initialize(const char *, const char *);
+int tapdisk_server_complete(void);
+int tapdisk_server_run(void);
+void tapdisk_server_iterate(void);
+
+int tapdisk_server_openlog(const char *, int, int);
+void tapdisk_server_closelog(void);
+void tapdisk_start_logging(const char *, const char *);
+void tapdisk_stop_logging(void);
+
+#endif
diff --git a/tools/blktap3/drivers/tapdisk-stats.h
b/tools/blktap3/drivers/tapdisk-stats.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-stats.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2010, Citrix Systems, Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _TAPDISK_STATS_H_
+#define _TAPDISK_STATS_H_
+
+#include <string.h>
+
+#define TD_STATS_MAX_DEPTH 8
+
+struct tapdisk_stats_ctx {
+ void *pos;
+
+ void *buf;
+ size_t size;
+
+ int n_elem[TD_STATS_MAX_DEPTH];
+ int depth;
+};
+
+typedef struct tapdisk_stats_ctx td_stats_t;
+
+static inline void
+tapdisk_stats_init(td_stats_t * st, char *buf, size_t size)
+{
+ memset(st, 0, sizeof(*st));
+
+ st->pos = buf;
+ st->buf = buf;
+ st->size = size;
+}
+
+static inline size_t tapdisk_stats_length(td_stats_t * st)
+{
+ return st->pos - st->buf;
+}
+
+void tapdisk_stats_enter(td_stats_t * st, char t);
+void tapdisk_stats_leave(td_stats_t * st, char t);
+void tapdisk_stats_field(td_stats_t * st, const char *key,
+ const char *conv, ...);
+void tapdisk_stats_val(td_stats_t * st, const char *conv, ...);
+
+#endif /* _TAPDISK_STATS_H_ */
diff --git a/tools/blktap3/drivers/tapdisk-utils.h
b/tools/blktap3/drivers/tapdisk-utils.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk-utils.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _TAPDISK_UTILS_H_
+#define _TAPDISK_UTILS_H_
+
+#include <inttypes.h>
+#include <sys/time.h>
+#include <stddef.h>
+
+#define MAX_NAME_LEN 1000
+#define TD_SYSLOG_IDENT_MAX 32
+#define TD_SYSLOG_STRTIME_LEN 15
+
+int tapdisk_syslog_facility(const char *);
+char *tapdisk_syslog_ident(const char *);
+size_t tapdisk_syslog_strftime(char *, size_t, const struct timeval *);
+size_t tapdisk_syslog_strftv(char *, size_t, const struct timeval *);
+int tapdisk_set_resource_limits(void);
+int tapdisk_namedup(char **, const char *);
+int tapdisk_parse_disk_type(const char *, char **, int *);
+int tapdisk_get_image_size(int, uint64_t *, uint32_t *);
+int tapdisk_linux_version(void);
+
+#endif
diff --git a/tools/blktap2/drivers/tapdisk-vbd.h
b/tools/blktap3/drivers/tapdisk-vbd.h
copy from tools/blktap2/drivers/tapdisk-vbd.h
copy to tools/blktap3/drivers/tapdisk-vbd.h
--- a/tools/blktap2/drivers/tapdisk-vbd.h
+++ b/tools/blktap3/drivers/tapdisk-vbd.h
@@ -1,4 +1,4 @@
-/*
+/*
* Copyright (c) 2008, XenSource Inc.
* All rights reserved.
*
@@ -24,18 +24,18 @@
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-*/
+ */
#ifndef _TAPDISK_VBD_H_
#define _TAPDISK_VBD_H_
#include <sys/time.h>
-#include <xenctrl.h>
-#include <xen/io/blkif.h>
#include "tapdisk.h"
#include "scheduler.h"
#include "tapdisk-image.h"
+#include "sring/td-blkif.h"
+#define TD_VBD_REQUEST_TIMEOUT 120
#define TD_VBD_MAX_RETRIES 100
#define TD_VBD_RETRY_INTERVAL 1
@@ -47,75 +47,54 @@
#define TD_VBD_PAUSED 0x0020
#define TD_VBD_SHUTDOWN_REQUESTED 0x0040
#define TD_VBD_LOCKING 0x0080
-#define TD_VBD_RETRY_NEEDED 0x0100
-#define TD_VBD_LOG_DROPPED 0x0200
+#define TD_VBD_LOG_DROPPED 0x0100
-typedef struct td_ring td_ring_t;
-typedef struct td_vbd_request td_vbd_request_t;
-typedef struct td_vbd_driver_info td_vbd_driver_info_t;
-typedef struct td_vbd_handle td_vbd_t;
-typedef void (*td_vbd_cb_t) (void *, blkif_response_t *);
+#define TD_VBD_SECONDARY_DISABLED 0
+#define TD_VBD_SECONDARY_MIRROR 1
+#define TD_VBD_SECONDARY_STANDBY 2
-struct td_ring {
- int fd;
- char *mem;
- blkif_sring_t *sring;
- blkif_back_ring_t fe_ring;
- unsigned long vstart;
-};
-
-struct td_vbd_request {
- blkif_request_t req;
- int16_t status;
-
- int error;
- int blocked; /* blocked on a dependency */
- int submitting;
- int secs_pending;
- int num_retries;
- struct timeval last_try;
-
- td_vbd_t *vbd;
- struct list_head next;
-};
-
-struct td_vbd_driver_info {
- char *params;
- int type;
- struct list_head next;
-};
+TAILQ_HEAD(tqh_td_vbd_handle, td_vbd_handle);
struct td_vbd_handle {
+ /**
+ * type:/path/to/file
+ */
char *name;
- td_uuid_t uuid;
- int minor;
+ /**
+ * shared ring
+ */
+ struct td_xenblkif *tap;
- struct list_head driver_stack;
-
- int storage;
-
- uint8_t reopened;
- uint8_t reactivated;
td_flag_t flags;
td_flag_t state;
- struct list_head images;
+ struct tqh_td_image_handle images;
- struct list_head new_requests;
- struct list_head pending_requests;
- struct list_head failed_requests;
- struct list_head completed_requests;
+ int parent_devnum;
+ char *secondary_name;
+ td_image_t *secondary;
+ uint8_t secondary_mode;
- td_vbd_request_t request_list[MAX_REQUESTS];
+ /* TODO ??? */
+ int FIXME_enospc_redirect_count_enabled;
+ uint64_t FIXME_enospc_redirect_count;
- td_ring_t ring;
- event_id_t ring_event_id;
+ /* when we encounter ENOSPC on the primary leaf image in mirror mode,
+ * we need to remove it from the VBD chain so that writes start going
+ * on the secondary leaf. However, we cannot free the image at that
+ * time since it might still have in-flight treqs referencing it.
+ * Therefore, we move it into 'retired' until shutdown. */
+ td_image_t *retired;
- td_vbd_cb_t callback;
- void *argument;
+ struct tqh_td_vbd_request new_requests;
+ struct tqh_td_vbd_request pending_requests;
+ struct tqh_td_vbd_request failed_requests;
+ struct tqh_td_vbd_request completed_requests;
- struct list_head next;
+ td_vbd_request_t request_list[MAX_REQUESTS]; /* XXX */
+
+ TAILQ_ENTRY(td_vbd_handle) entry;
struct timeval ts;
@@ -125,83 +104,119 @@ struct td_vbd_handle {
uint64_t secs_pending;
uint64_t retries;
uint64_t errors;
+ td_sector_count_t secs;
};
#define tapdisk_vbd_for_each_request(vreq, tmp, list) \
- list_for_each_entry_safe((vreq), (tmp), (list), next)
+ TAILQ_FOREACH_SAFE((vreq), (list), next, (tmp))
#define tapdisk_vbd_for_each_image(vbd, image, tmp) \
- list_for_each_entry_safe((image), (tmp), &(vbd)->images, next)
+ tapdisk_for_each_image_safe(image, tmp, &vbd->images)
+/**
+ * Removes the request from its current queue and inserts it to the specified
+ * one.
+ */
static inline void
-tapdisk_vbd_move_request(td_vbd_request_t *vreq, struct list_head *dest)
+tapdisk_vbd_move_request(td_vbd_request_t * vreq,
+ struct tqh_td_vbd_request *dest)
{
- list_del(&vreq->next);
- INIT_LIST_HEAD(&vreq->next);
- list_add_tail(&vreq->next, dest);
+ assert(vreq);
+ assert(dest);
+
+ assert(vreq->list_head);
+ TAILQ_REMOVE(vreq->list_head, vreq, next);
+
+ TAILQ_INSERT_TAIL(dest, vreq, next);
+
+ vreq->list_head = dest;
}
static inline void
tapdisk_vbd_add_image(td_vbd_t *vbd, td_image_t *image)
{
- list_add_tail(&image->next, &vbd->images);
+ TAILQ_INSERT_TAIL(&vbd->images, image, entry);
}
static inline int
tapdisk_vbd_is_last_image(td_vbd_t *vbd, td_image_t *image)
{
- return list_is_last(&image->next, &vbd->images);
+ return TAILQ_LAST(&vbd->images, tqh_td_image_handle) == image;
}
-td_image_t *
-tapdisk_vbd_first_image(td_vbd_t *vbd);
+/**
+ * Retrieves the first image of this VBD.
+ */
+static inline td_image_t *
+tapdisk_vbd_first_image(td_vbd_t *vbd)
+{
+ td_image_t *image = NULL;
+ if (!TAILQ_EMPTY(&vbd->images))
+ image = TAILQ_FIRST(&vbd->images);
+ return image;
+}
static inline td_image_t *
tapdisk_vbd_last_image(td_vbd_t *vbd)
{
- return list_entry(vbd->images.prev, td_image_t, next);
+ td_image_t *image = NULL;
+ if (!TAILQ_EMPTY(&vbd->images))
+ image = TAILQ_LAST(&vbd->images, tqh_td_image_handle);
+ return image;
}
-static inline td_image_t *
-tapdisk_vbd_next_image(td_image_t *image)
+static inline td_image_t *tapdisk_vbd_next_image(td_image_t * image)
{
- return list_entry(image->next.next, td_image_t, next);
+ return TAILQ_NEXT(image, entry);
}
-td_vbd_t *tapdisk_vbd_create(td_uuid_t);
-int tapdisk_vbd_initialize(td_uuid_t);
-void tapdisk_vbd_set_callback(td_vbd_t *, td_vbd_cb_t, void *);
-int tapdisk_vbd_parse_stack(td_vbd_t *vbd, const char *path);
-int tapdisk_vbd_open(td_vbd_t *, const char *, uint16_t,
- uint16_t, int, const char *, td_flag_t);
+td_vbd_t *tapdisk_vbd_create(void);
+
+int tapdisk_vbd_initialize(int rfd, int wfd, const char * params);
+
+/*
+ * XXX Function definition commented out in blktap2.5.
+ */
+int tapdisk_vbd_open(td_vbd_t *, const char *, int, const char *, td_flag_t);
+
int tapdisk_vbd_close(td_vbd_t *);
-void tapdisk_vbd_free(td_vbd_t *);
-void tapdisk_vbd_free_stack(td_vbd_t *);
-int tapdisk_vbd_open_stack(td_vbd_t *, uint16_t, td_flag_t);
-int tapdisk_vbd_open_vdi(td_vbd_t *, const char *,
- uint16_t, uint16_t, td_flag_t);
+/**
+ * Opens a VDI.
+ *
+ * @params vbd output parameter that receives a handle to the opened VDI
+ * @param params type:/path/to/file
+ * @params flags TD_OPEN_* TODO which TD_OPEN_* flags are honored? How does
+ * each flag affect the behavior of this functions? Move TD_OPEN_* flag
+ * definitions close to this function (check if they're used only by this
+ * function)?
+ * @param prt_path parent /path/to/file (optional)
+ * @returns 0 on success
+ */
+int tapdisk_vbd_open_vdi(td_vbd_t * vbd, const char *params, td_flag_t flags,
+ const char * prt_path);
+
+/**
+ * Closes a VDI.
+ */
void tapdisk_vbd_close_vdi(td_vbd_t *);
-int tapdisk_vbd_attach(td_vbd_t *, const char *, int);
-void tapdisk_vbd_detach(td_vbd_t *);
-
+int tapdisk_vbd_queue_request(td_vbd_t *, td_vbd_request_t *);
void tapdisk_vbd_forward_request(td_request_t);
-int tapdisk_vbd_get_image_info(td_vbd_t *, image_t *);
-int tapdisk_vbd_queue_ready(td_vbd_t *);
+int tapdisk_vbd_get_disk_info(td_vbd_t *, td_disk_info_t *);
int tapdisk_vbd_retry_needed(td_vbd_t *);
int tapdisk_vbd_quiesce_queue(td_vbd_t *);
int tapdisk_vbd_start_queue(td_vbd_t *);
int tapdisk_vbd_issue_requests(td_vbd_t *);
int tapdisk_vbd_kill_queue(td_vbd_t *);
int tapdisk_vbd_pause(td_vbd_t *);
-int tapdisk_vbd_resume(td_vbd_t *, const char *, uint16_t);
-int tapdisk_vbd_kick(td_vbd_t *);
+int tapdisk_vbd_resume(td_vbd_t *, const char *);
+void tapdisk_vbd_kick(td_vbd_t *);
void tapdisk_vbd_check_state(td_vbd_t *);
+int tapdisk_vbd_recheck_state(td_vbd_t *);
void tapdisk_vbd_check_progress(td_vbd_t *);
void tapdisk_vbd_debug(td_vbd_t *);
-
-void tapdisk_vbd_complete_vbd_request(td_vbd_t *, td_vbd_request_t *);
+void tapdisk_vbd_stats(td_vbd_t *, td_stats_t *);
#endif
diff --git a/tools/blktap3/drivers/tapdisk.h b/tools/blktap3/drivers/tapdisk.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk.h
@@ -0,0 +1,251 @@
+/*
+ * Copyright (c) 2007, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of XenSource Inc. nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Some notes on the tap_disk interface:
+ *
+ * tap_disk aims to provide a generic interface to easily implement new
+ * types of image accessors. The structure-of-function-calls is similar
+ * to disk interfaces used in qemu/denali/etc, with the significant
+ * difference being the expectation of asynchronous rather than synchronous
+ * I/O. The asynchronous interface is intended to allow lots of requests to
+ * be pipelined through a disk, without the disk requiring any of its own
+ * threads of control. As such, a batch of requests is delivered to the disk
+ * using:
+ *
+ * td_queue_[read,write]()
+ *
+ * and passing in a completion callback, which the disk is responsible for
+ * tracking. Disks should transform these requests as necessary and return
+ * the resulting iocbs to tapdisk using td_prep_[read,write]() and
+ * td_queue_tiocb().
+ *
+ * NOTE: tapdisk uses the number of sectors submitted per request as a
+ * ref count. Plugins must use the callback function to communicate the
+ * completion -- or error -- of every sector submitted to them.
+ *
+ * td_get_parent_id returns:
+ * 0 if parent id successfully retrieved
+ * TD_NO_PARENT if no parent exists
+ * -errno on error
+ */
+
+#ifndef _TAPDISK_H_
+#define _TAPDISK_H_
+
+#include <sys/time.h>
+#include <stdint.h>
+#include <assert.h>
+
+// XXX?
+//#include "blktaplib.h"
+#include "blktap3.h"
+
+// TODO necessary?
+#include "tapdisk-log.h"
+#include "tapdisk-utils.h"
+#include "tapdisk-stats.h"
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a)[0])
+
+#define MAX_SEGMENTS_PER_REQ 11
+#define MAX_REQUESTS 32U
+#define SECTOR_SHIFT 9
+#define DEFAULT_SECTOR_SIZE 512
+
+#define TAPDISK_DATA_REQUESTS (MAX_REQUESTS * MAX_SEGMENTS_PER_REQ)
+
+//#define BLK_NOT_ALLOCATED (-99)
+#define TD_NO_PARENT 1
+
+#define MAX_RAMDISK_SIZE 1024000 /*500MB disk limit */
+
+#define TD_OP_READ 0
+#define TD_OP_WRITE 1
+
+#define TD_OPEN_QUIET 0x00001
+#define TD_OPEN_QUERY 0x00002
+#define TD_OPEN_RDONLY 0x00004
+#define TD_OPEN_STRICT 0x00008
+#define TD_OPEN_SHAREABLE 0x00010
+#define TD_OPEN_ADD_CACHE 0x00020
+#define TD_OPEN_VHD_INDEX 0x00040
+#define TD_OPEN_LOG_DIRTY 0x00080
+#define TD_OPEN_LOCAL_CACHE 0x00100
+#define TD_OPEN_REUSE_PARENT 0x00200
+#define TD_OPEN_SECONDARY 0x00400
+#define TD_OPEN_STANDBY 0x00800
+#define TD_IGNORE_ENOSPC 0x01000
+
+#define TD_CREATE_SPARSE 0x00001
+#define TD_CREATE_MULTITYPE 0x00002
+
+#define td_flag_set(word, flag) ((word) |= (flag))
+#define td_flag_clear(word, flag) ((word) &= ~(flag))
+#define td_flag_test(word, flag) ((word) & (flag))
+
+typedef uint16_t td_uuid_t;
+typedef uint32_t td_flag_t;
+typedef uint64_t td_sector_t;
+typedef struct td_disk_id td_disk_id_t;
+typedef struct td_disk_info td_disk_info_t;
+typedef struct td_request td_request_t;
+typedef struct td_driver_handle td_driver_t;
+typedef struct td_image_handle td_image_t;
+typedef struct td_sector_count td_sector_count_t;
+typedef struct td_vbd_request td_vbd_request_t;
+typedef struct td_vbd_handle td_vbd_t;
+
+/*
+ * Prototype of the callback to activate as requests complete.
+ */
+typedef void (*td_callback_t) (td_request_t, int);
+typedef void (*td_vreq_callback_t) (td_vbd_request_t *, int, void *, int);
+
+struct td_disk_id {
+ char *name;
+ int type;
+ int flags;
+};
+
+struct td_disk_info {
+ td_sector_t size;
+ long sector_size;
+ uint32_t info;
+};
+
+
+TAILQ_HEAD(tqh_td_vbd_request, td_vbd_request);
+
+struct td_vbd_request {
+
+ /**
+ * Operation: read/write
+ */
+ int op;
+
+ /**
+ * Start sector.
+ */
+ td_sector_t sec;
+
+ /**
+ * Scatter/gather list.
+ */
+ struct td_iovec *iov;
+ int iovcnt;
+
+ /**
+ * Completion callback.
+ */
+ td_vreq_callback_t cb;
+
+ void *token;
+ const char *name;
+
+ int error;
+ int prev_error;
+
+ int submitting;
+ int secs_pending;
+ int num_retries;
+ struct timeval ts;
+ struct timeval last_try;
+
+ /**
+ * VBD this request belongs to.
+ */
+ td_vbd_t *vbd;
+
+ /*
+ * linked list of struct td_vbd_request
+ */
+ TAILQ_ENTRY(td_vbd_request) next;
+
+ /*
+ * TODO list head of what?
+ */
+ struct tqh_td_vbd_request *list_head;
+};
+
+/* TODO why have these two types (td_request and td_vbd_request) separate? */
+struct td_request {
+ int op;
+ void *buf;
+
+ td_sector_t sec;
+ int secs;
+
+ td_image_t *image;
+
+ td_callback_t cb;
+ void *cb_data;
+
+ int sidx;
+ td_vbd_request_t *vreq;
+};
+
+/*
+ * Structure describing the interface to a virtual disk implementation.
+ * See note at the top of this file describing this interface.
+ */
+struct tap_disk {
+ const char *disk_type;
+ td_flag_t flags;
+ int private_data_size;
+ int (*td_open) (td_driver_t *, const char *, td_flag_t);
+ int (*td_close) (td_driver_t *);
+ int (*td_get_parent_id) (td_driver_t *, td_disk_id_t *);
+ int (*td_validate_parent) (td_driver_t *, td_driver_t *, td_flag_t);
+ void (*td_queue_read) (td_driver_t *, td_request_t);
+ void (*td_queue_write) (td_driver_t *, td_request_t);
+ void (*td_debug) (td_driver_t *);
+ void (*td_stats) (td_driver_t *, td_stats_t *);
+};
+
+struct td_sector_count {
+ td_sector_t rd;
+ td_sector_t wr;
+};
+
+static inline void
+td_sector_count_add(td_sector_count_t * s, td_sector_t v, int write)
+{
+ if (write)
+ s->wr += v;
+ else
+ s->rd += v;
+}
+
+void td_panic(void);
+
+/* TODO why not use struct iovec? */
+struct td_iovec {
+ void *base;
+ unsigned int secs;
+};
+
+#endif /* __TAPDISK_H__ */
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