[stgt] [PATCH] Make the backing-store modules shared objects that are loaded at runtime

ronnie sahlberg ronniesahlberg at gmail.com
Tue Aug 13 17:10:18 CEST 2013


Tomo ?

On Sat, Aug 10, 2013 at 2:37 AM, ronnie sahlberg
<ronniesahlberg at gmail.com> wrote:
> On Fri, Aug 9, 2013 at 11:09 PM, Dan Mick <dan.mick at inktank.com> wrote:
>> I can confirm that, with all instances of 'rdb' changed to 'rbd', and the
>> obvious change to bs_rbd.c, this works for bs_rbd as well.  If I'd been more
>> intelligent I'd have committed your patch locally before hacking on it.
>> It's late. :)
>
> Thanks. I have updated the patch.
>>
>> +1 on the idea and overall structure; it would be interesting in particular
>> to hear others' opinions about the choice of /usr/lib/tgtd/backing-store,
>> although it seems fine to me.
>
> I have no strong feelings about where to store the modules so if
> anyone has a better suggestion for the directory, please let me know
> and I'll change it.
>
>
>>
>> Ceph users would benefit greatly from the ability for the official released
>> packages (assuming the package maintainers will do it) to contain the rbd
>> backend without requiring compilation.
>
> Yes. It would also be really neat if at a later stage one could
> unload/reload a bs module at runtime. This I think would greatly
> improve the experience for people that are developing and testing
> backends.
>
>>
>>
>> On 08/09/2013 10:47 PM, Dan Mick wrote:
>>>
>>> This would be super-cool, as it would allow building and distributing
>>> rbd support without requiring users of the package to install Ceph just
>>> to use stgt without Ceph.
>>>
>>> Some initial comments below:
>>>
>>> On 08/09/2013 04:02 PM, Ronnie Sahlberg wrote:
>>>>
>>>> Turn most of TGTD into a shared library libtgt.so and install it under
>>>> $(PREFIX)/lib/tgtd
>>>>
>>>> Change the six backing stores  bs_aio/null/rdb/rdwr/sg/ssc into shared
>>>> objects
>>>> and install them under $(PREFIX)/lib/tgtd/backing-store
>>>>
>>>> When tgtd is starting, have it traverse the directory for backing
>>>> stores and
>>>> automatically load and initialize all backing stores files that are
>>>> found.
>>>>
>>>> This allows for example to distribute bs_aio.so as a separate package
>>>> since it has additional dependencies (libaio) that tgtd itself does
>>>> not have
>>>> Similarly for bs_rdb.so.
>>>> This means that core TGTD can be distributed with minimal dependencies
>>>> and backends that add additional dependencies can be distributed
>>>> separately.
>>>>
>>>> Once we have this basics for a modularized TGTD later patches can
>>>> build ontop
>>>> of this and add features such as :
>>>> * list all modules and which luns are using them
>>>> * unload module if unused
>>>> * re-load module
>>>> But that can come in later patches. Lets get the basics in first.
>>>>
>>>> Signed-off-by: Ronnie Sahlberg <ronniesahlberg at gmail.com>
>>>> ---
>>>>   usr/Makefile  |   42 ++++++---
>>>>   usr/bs.c      |   46 +++++++++
>>>>   usr/bs_aio.c  |    2 +-
>>>>   usr/bs_null.c |    2 +-
>>>>   usr/bs_rdwr.c |    2 +-
>>>>   usr/bs_sg.c   |    2 +-
>>>>   usr/bs_ssc.c  |    2 +-
>>>
>>>
>>> No 2-line change to bs_rbd.c?
>>>
>>>>   usr/target.c  |  285
>>>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++--
>>>>   usr/tgtd.c    |  276
>>>> +-------------------------------------------------------
>>>>   usr/tgtd.h    |    2 +
>>>>   10 files changed, 360 insertions(+), 301 deletions(-)
>>>>
>>>> diff --git a/usr/Makefile b/usr/Makefile
>>>> index 453eb1a..5c76f43 100644
>>>> --- a/usr/Makefile
>>>> +++ b/usr/Makefile
>>>> @@ -1,4 +1,5 @@
>>>>   sbindir ?= $(PREFIX)/sbin
>>>> +libdir ?= $(PREFIX)/lib/tgtd
>>>>
>>>>   ifneq ($(shell test -e /usr/include/linux/signalfd.h && echo 1),)
>>>>   CFLAGS += -DUSE_SIGNALFD
>>>> @@ -11,17 +12,14 @@ endif
>>>>   TGTD_OBJS += $(addprefix iscsi/, conn.o param.o session.o \
>>>>           iscsid.o target.o chap.o sha1.o md5.o transport.o iscsi_tcp.o \
>>>>           isns.o)
>>>> -TGTD_OBJS += bs_rdwr.o
>>>>
>>>>   ifneq ($(CEPH_RBD),)
>>>> -TGTD_OBJS += bs_rbd.o
>>>> -LIBS += -lrados -lrbd
>>>> +BS_OBJS += bs_rdb.so
>>>
>>>
>>> bs_rbd.so, not rdb
>>>
>>> It may seem weird to compile, but it *should* be enough to add package
>>> 'librbd1' (which will also pull in librados2) to allow the build with
>>> CEPH_RBD enabled.  If Tomo agrees this patch is worthwhile, I'd sure
>>> like to see it go in with all bsdrvs supported.
>>>
>>>>   endif
>>>>
>>>>   ifneq ($(shell test -e /usr/include/sys/eventfd.h && test -e
>>>> /usr/include/libaio.h && echo 1),)
>>>>   CFLAGS += -DUSE_EVENTFD
>>>> -TGTD_OBJS += bs_aio.o
>>>> -LIBS += -laio
>>>> +BS_OBJS += bs_aio.so
>>>>   endif
>>>>
>>>>   ifneq ($(ISCSI_RDMA),)
>>>> @@ -40,25 +38,32 @@ CFLAGS += -g -O2 -fno-strict-aliasing
>>>>   endif
>>>>   CFLAGS += -Wall -Wstrict-prototypes -fPIC
>>>>   CFLAGS += -DTGT_VERSION=\"$(VERSION)$(EXTRAVERSION)\"
>>>> +CFLAGS += -DBSDIR=\"$(DESTDIR)$(libdir)/backing-store\"
>>>>
>>>>   LIBS += -lpthread
>>>>
>>>>   PROGRAMS += tgtd tgtadm tgtimg
>>>> -TGTD_OBJS += tgtd.o mgmt.o target.o scsi.o log.o driver.o util.o
>>>> work.o \
>>>> -        concat_buf.o parser.o spc.o sbc.o mmc.o osd.o scc.o smc.o \
>>>> -        ssc.o bs_ssc.o libssc.o \
>>>> -        bs_null.o bs_sg.o bs.o libcrc32c.o
>>>> +TGTD_OBJS += tgtd.o
>>>> +LIBTGT_OBJS = bs.o \
>>>> +    concat_buf.o driver.o libcrc32c.o libssc.o log.o mgmt.o mmc.o \
>>>> +    osd.o parser.o sbc.o scc.o scsi.o smc.o spc.o ssc.o \
>>>> +    target.o util.o work.o
>>>> +
>>>> +BS_OBJS += bs_null.so bs_rdwr.so bs_sg.so bs_ssc.so
>>>>
>>>>   TGTD_DEP = $(TGTD_OBJS:.o=.d)
>>>>
>>>>   .PHONY:all
>>>> -all: $(PROGRAMS)
>>>> +all: libtgt.so $(PROGRAMS) $(BS_OBJS)
>>>>
>>>>   tgtd: $(TGTD_OBJS)
>>>> -    $(CC) $^ -o $@ $(LIBS)
>>>> +    $(CC) $^ -o $@ $(LIBS) libtgt.so
>>>>
>>>>   -include $(TGTD_DEP)
>>>>
>>>> +libtgt.so: $(LIBTGT_OBJS)
>>>> +    $(CC) -shared -fPIC -DPIC $^ -o $@  -ldl
>>>> +
>>>>   TGTADM_OBJS = tgtadm.o concat_buf.o
>>>>   TGTADM_DEP = $(TGTADM_OBJS:.o=.d)
>>>>
>>>> @@ -79,11 +84,24 @@ tgtimg: $(TGTIMG_OBJS)
>>>>       $(CC) -c $(CFLAGS) $*.c -o $*.o
>>>>       @$(CC) -MM $(CFLAGS) -MF $*.d -MT $*.o $*.c
>>>>
>>>> +%.so: %.c
>>>> +    $(CC) -shared $(CFLAGS) $*.c -o $*.so
>>>> +
>>>> +bs_aio.so: bs_aio.c
>>>> +    $(CC) -shared $(CFLAGS) bs_aio.c -o bs_aio.so -laio
>>>> +
>>>> +bs_rdb.so: bs_rdb.c
>>>> +    $(CC) -shared $(CFLAGS) bs_rdb.c -o bs_rdb.so -lrados -lrbd
>>>> +
>>>>   .PHONY: install
>>>>   install: $(PROGRAMS)
>>>>       install -d -m 755 $(DESTDIR)$(sbindir)
>>>>       install -m 755 $(PROGRAMS) $(DESTDIR)$(sbindir)
>>>> +    install -d -m 755 $(DESTDIR)$(libdir)/backing-store
>>>> +    install -m 755 $(BS_OBJS) $(DESTDIR)$(libdir)/backing-store
>>>> +    install -m 755 libtgt.so $(DESTDIR)$(libdir)
>>>> +    ldconfig $(DESTDIR)$(libdir)
>>>>
>>>>   .PHONY: clean
>>>>   clean:
>>>> -    rm -f *.[od] $(PROGRAMS) iscsi/*.[od] ibmvio/*.[od] fc/*.[od]
>>>> +    rm -f *.[od] *.so $(PROGRAMS) iscsi/*.[od] ibmvio/*.[od] fc/*.[od]
>>>> diff --git a/usr/bs.c b/usr/bs.c
>>>> index 65c332e..7974e3a 100644
>>>> --- a/usr/bs.c
>>>> +++ b/usr/bs.c
>>>> @@ -19,6 +19,8 @@
>>>>    * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
>>>>    * 02110-1301 USA
>>>>    */
>>>> +#include <dirent.h>
>>>> +#include <dlfcn.h>
>>>>   #include <errno.h>
>>>>   #include <string.h>
>>>>   #include <inttypes.h>
>>>> @@ -307,10 +309,54 @@ destroy_cond_mutex:
>>>>       return 1;
>>>>   }
>>>>
>>>> +void update_lbppbe(struct scsi_lu *lu, int blksize)
>>>> +{
>>>> +    lu->attrs.lbppbe = 0;
>>>> +    while (blksize > (1U << lu->blk_shift)) {
>>>> +        lu->attrs.lbppbe++;
>>>> +        blksize >>= 1;
>>>> +    }
>>>> +}
>>>> +
>>>>   int bs_init(void)
>>>>   {
>>>> +    DIR *dir;
>>>>       int ret;
>>>>
>>>> +    dir = opendir(BSDIR);
>>>> +    if (dir == NULL) {
>>>> +        eprintf("could not open backing-store module directory %s\n",
>>>> +            BSDIR);
>>>> +    } else {
>>>> +        struct dirent *dirent;
>>>> +        void *handle;
>>>> +        while ((dirent = readdir(dir))) {
>>>> +            char *soname;
>>>> +            void (*register_bs_module)(void);
>>>> +
>>>> +            if (dirent->d_name[0] == '.') {
>>>> +                continue;
>>>> +            }
>>>> +
>>>> +            asprintf(&soname, "%s/%s", BSDIR, dirent->d_name);
>>>> +            handle = dlopen(soname, RTLD_NOW|RTLD_LOCAL);
>>>> +            if (handle == NULL) {
>>>> +                eprintf("failed to dlopen backing-store "
>>>> +                    "module %s error %s \n",
>>>> +                    soname, dlerror());
>>>> +                continue;
>>>> +            }
>>>> +            register_bs_module = dlsym(handle, "register_bs_module");
>>>> +            if (register_bs_module == NULL) {
>>>> +                eprintf("could not find register_bs_module "
>>>> +                    "symbol in module %s\n",
>>>> +                    soname);
>>>> +                continue;
>>>> +            }
>>>> +            register_bs_module();
>>>> +        }
>>>> +        closedir(dir);
>>>> +    }
>>>>       ret = bs_init_signalfd();
>>>>       if (!ret) {
>>>>           eprintf("use signalfd notification\n");
>>>> diff --git a/usr/bs_aio.c b/usr/bs_aio.c
>>>> index c0cbadd..cc59cf6 100644
>>>> --- a/usr/bs_aio.c
>>>> +++ b/usr/bs_aio.c
>>>> @@ -414,7 +414,7 @@ static struct backingstore_template aio_bst = {
>>>>       .bs_cmd_submit      = bs_aio_cmd_submit,
>>>>   };
>>>>
>>>> -__attribute__((constructor)) static void bs_rdwr_constructor(void)
>>>> +void register_bs_module(void)
>>>>   {
>>>>       register_backingstore_template(&aio_bst);
>>>>   }
>>>> diff --git a/usr/bs_null.c b/usr/bs_null.c
>>>> index d463f18..4dbe144 100644
>>>> --- a/usr/bs_null.c
>>>> +++ b/usr/bs_null.c
>>>> @@ -56,7 +56,7 @@ static struct backingstore_template null_bst = {
>>>>       .bs_cmd_submit        = bs_null_cmd_submit,
>>>>   };
>>>>
>>>> -__attribute__((constructor)) static void bs_null_constructor(void)
>>>> +void register_bs_module(void)
>>>>   {
>>>>       register_backingstore_template(&null_bst);
>>>>   }
>>>> diff --git a/usr/bs_rdwr.c b/usr/bs_rdwr.c
>>>> index 47d2d99..82807d1 100644
>>>> --- a/usr/bs_rdwr.c
>>>> +++ b/usr/bs_rdwr.c
>>>> @@ -423,7 +423,7 @@ static struct backingstore_template rdwr_bst = {
>>>>       .bs_oflags_supported    = O_SYNC | O_DIRECT,
>>>>   };
>>>>
>>>> -__attribute__((constructor)) static void bs_rdwr_constructor(void)
>>>> +void register_bs_module(void)
>>>>   {
>>>>       register_backingstore_template(&rdwr_bst);
>>>>   }
>>>> diff --git a/usr/bs_sg.c b/usr/bs_sg.c
>>>> index 5f1e687..43dc5f3 100644
>>>> --- a/usr/bs_sg.c
>>>> +++ b/usr/bs_sg.c
>>>> @@ -517,7 +517,7 @@ static struct device_type_template sg_template = {
>>>>       .cmd_passthrough    = bs_sg_rw,
>>>>   };
>>>>
>>>> -__attribute__((constructor)) static void bs_sg_constructor(void)
>>>> +void register_bs_module(void)
>>>>   {
>>>>       register_backingstore_template(&sg_bst);
>>>>       register_backingstore_template(&bsg_bst);
>>>> diff --git a/usr/bs_ssc.c b/usr/bs_ssc.c
>>>> index 117e274..98b84b5 100644
>>>> --- a/usr/bs_ssc.c
>>>> +++ b/usr/bs_ssc.c
>>>> @@ -702,7 +702,7 @@ static struct backingstore_template ssc_bst = {
>>>>       .bs_cmd_submit        = bs_thread_cmd_submit,
>>>>   };
>>>>
>>>> -__attribute__((constructor)) static void bs_ssc_constructor(void)
>>>> +void register_bs_module(void)
>>>>   {
>>>>       register_backingstore_template(&ssc_bst);
>>>>   }
>>>> diff --git a/usr/target.c b/usr/target.c
>>>> index b1729b3..b7872fb 100644
>>>> --- a/usr/target.c
>>>> +++ b/usr/target.c
>>>> @@ -19,6 +19,7 @@
>>>>    * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
>>>>    * 02110-1301 USA
>>>>    */
>>>> +#include <ctype.h>
>>>>   #include <errno.h>
>>>>   #include <fcntl.h>
>>>>   #include <inttypes.h>
>>>> @@ -27,8 +28,10 @@
>>>>   #include <string.h>
>>>>   #include <time.h>
>>>>   #include <unistd.h>
>>>> +#include <sys/epoll.h>
>>>>   #include <sys/socket.h>
>>>>   #include <sys/time.h>
>>>> +#include <sys/wait.h>
>>>>
>>>>   #include "list.h"
>>>>   #include "util.h"
>>>> @@ -42,8 +45,11 @@
>>>>   #include "spc.h"
>>>>
>>>>   static LIST_HEAD(device_type_list);
>>>> +static LIST_HEAD(tgt_events_list);
>>>> +static LIST_HEAD(tgt_sched_events_list);
>>>>
>>>>   static struct target global_target;
>>>> +int ep_fd;
>>>>
>>>>   int device_type_register(struct device_type_template *t)
>>>>   {
>>>> @@ -2411,15 +2417,6 @@ tgtadm_err lld_show(struct concat_buf *b)
>>>>       return TGTADM_SUCCESS;
>>>>   }
>>>>
>>>> -void update_lbppbe(struct scsi_lu *lu, int blksize)
>>>> -{
>>>> -    lu->attrs.lbppbe = 0;
>>>> -    while (blksize > (1U << lu->blk_shift)) {
>>>> -        lu->attrs.lbppbe++;
>>>> -        blksize >>= 1;
>>>> -    }
>>>> -}
>>>> -
>>>>   int is_system_available(void)
>>>>   {
>>>>       return (sys_state == TGT_SYSTEM_READY);
>>>> @@ -2430,6 +2427,276 @@ int is_system_inactive(void)
>>>>       return list_empty(&target_list);
>>>>   }
>>>>
>>>> +int tgt_event_add(int fd, int events, event_handler_t handler, void
>>>> *data)
>>>> +{
>>>> +    struct epoll_event ev;
>>>> +    struct event_data *tev;
>>>> +    int err;
>>>> +
>>>> +    tev = zalloc(sizeof(*tev));
>>>> +    if (!tev)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    tev->data = data;
>>>> +    tev->handler = handler;
>>>> +    tev->fd = fd;
>>>> +
>>>> +    memset(&ev, 0, sizeof(ev));
>>>> +    ev.events = events;
>>>> +    ev.data.ptr = tev;
>>>> +    err = epoll_ctl(ep_fd, EPOLL_CTL_ADD, fd, &ev);
>>>> +    if (err) {
>>>> +        eprintf("Cannot add fd, %m\n");
>>>> +        free(tev);
>>>> +    } else
>>>> +        list_add(&tev->e_list, &tgt_events_list);
>>>> +
>>>> +    return err;
>>>> +}
>>>> +
>>>> +static struct event_data *tgt_event_lookup(int fd)
>>>> +{
>>>> +    struct event_data *tev;
>>>> +
>>>> +    list_for_each_entry(tev, &tgt_events_list, e_list) {
>>>> +        if (tev->fd == fd)
>>>> +            return tev;
>>>> +    }
>>>> +    return NULL;
>>>> +}
>>>> +
>>>> +void tgt_event_del(int fd)
>>>> +{
>>>> +    struct event_data *tev;
>>>> +    int ret;
>>>> +
>>>> +    tev = tgt_event_lookup(fd);
>>>> +    if (!tev) {
>>>> +        eprintf("Cannot find event %d\n", fd);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    ret = epoll_ctl(ep_fd, EPOLL_CTL_DEL, fd, NULL);
>>>> +    if (ret < 0)
>>>> +        eprintf("fail to remove epoll event, %s\n", strerror(errno));
>>>> +
>>>> +    list_del(&tev->e_list);
>>>> +    free(tev);
>>>> +}
>>>> +
>>>> +int tgt_event_modify(int fd, int events)
>>>> +{
>>>> +    struct epoll_event ev;
>>>> +    struct event_data *tev;
>>>> +
>>>> +    tev = tgt_event_lookup(fd);
>>>> +    if (!tev) {
>>>> +        eprintf("Cannot find event %d\n", fd);
>>>> +        return -EINVAL;
>>>> +    }
>>>> +
>>>> +    memset(&ev, 0, sizeof(ev));
>>>> +    ev.events = events;
>>>> +    ev.data.ptr = tev;
>>>> +
>>>> +    return epoll_ctl(ep_fd, EPOLL_CTL_MOD, fd, &ev);
>>>> +}
>>>> +
>>>> +void tgt_init_sched_event(struct event_data *evt,
>>>> +              sched_event_handler_t sched_handler, void *data)
>>>> +{
>>>> +    evt->sched_handler = sched_handler;
>>>> +    evt->scheduled = 0;
>>>> +    evt->data = data;
>>>> +    INIT_LIST_HEAD(&evt->e_list);
>>>> +}
>>>> +
>>>> +void tgt_add_sched_event(struct event_data *evt)
>>>> +{
>>>> +    if (!evt->scheduled) {
>>>> +        evt->scheduled = 1;
>>>> +        list_add_tail(&evt->e_list, &tgt_sched_events_list);
>>>> +    }
>>>> +}
>>>> +
>>>> +void tgt_remove_sched_event(struct event_data *evt)
>>>> +{
>>>> +    if (evt->scheduled) {
>>>> +        evt->scheduled = 0;
>>>> +        list_del_init(&evt->e_list);
>>>> +    }
>>>> +}
>>>> +
>>>> +int tgt_exec_scheduled(void)
>>>> +{
>>>> +    struct list_head *last_sched;
>>>> +    struct event_data *tev, *tevn;
>>>> +    int work_remains = 0;
>>>> +
>>>> +    if (!list_empty(&tgt_sched_events_list)) {
>>>> +        /* execute only work scheduled till now */
>>>> +        last_sched = tgt_sched_events_list.prev;
>>>> +        list_for_each_entry_safe(tev, tevn, &tgt_sched_events_list,
>>>> +                     e_list) {
>>>> +            tgt_remove_sched_event(tev);
>>>> +            tev->sched_handler(tev);
>>>> +            if (&tev->e_list == last_sched)
>>>> +                break;
>>>> +        }
>>>> +        if (!list_empty(&tgt_sched_events_list))
>>>> +            work_remains = 1;
>>>> +    }
>>>> +    return work_remains;
>>>> +}
>>>> +
>>>> +/* strcpy, while eating multiple white spaces */
>>>> +static void str_spacecpy(char **dest, const char *src)
>>>> +{
>>>> +    const char *s = src;
>>>> +    char *d = *dest;
>>>> +
>>>> +    while (*s) {
>>>> +        if (isspace(*s)) {
>>>> +            if (!*(s+1))
>>>> +                break;
>>>> +            if (isspace(*(s+1))) {
>>>> +                s++;
>>>> +                continue;
>>>> +            }
>>>> +        }
>>>> +        *d++ = *s++;
>>>> +    }
>>>> +    *d = '\0';
>>>> +}
>>>> +
>>>> +int call_program(const char *cmd, void (*callback)(void *data, int
>>>> result),
>>>> +        void *data, char *output, int op_len, int flags)
>>>> +{
>>>> +    pid_t pid;
>>>> +    int fds[2], ret, i;
>>>> +    char *pos, arg[256];
>>>> +    char *argv[sizeof(arg) / 2];
>>>> +
>>>> +    i = 0;
>>>> +    pos = arg;
>>>> +    str_spacecpy(&pos, cmd);
>>>> +    if (strchr(cmd, ' ')) {
>>>> +        while (pos != '\0')
>>>> +            argv[i++] = strsep(&pos, " ");
>>>> +    } else
>>>> +        argv[i++] = arg;
>>>> +    argv[i] =  NULL;
>>>> +
>>>> +    ret = pipe(fds);
>>>> +    if (ret < 0) {
>>>> +        eprintf("pipe create failed for %s, %m\n", cmd);
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    dprintf("%s, pipe: %d %d\n", cmd, fds[0], fds[1]);
>>>> +
>>>> +    pid = fork();
>>>> +    if (pid < 0) {
>>>> +        eprintf("fork failed for: %s, %m\n", cmd);
>>>> +        close(fds[0]);
>>>> +        close(fds[1]);
>>>> +        return pid;
>>>> +    }
>>>> +
>>>> +    if (!pid) {
>>>> +        close(1);
>>>> +        ret = dup(fds[1]);
>>>> +        if (ret < 0) {
>>>> +            eprintf("dup failed for: %s, %m\n", cmd);
>>>> +            exit(-1);
>>>> +        }
>>>> +        close(fds[0]);
>>>> +        execv(argv[0], argv);
>>>> +
>>>> +        eprintf("execv failed for: %s, %m\n", cmd);
>>>> +        exit(-1);
>>>> +    } else {
>>>> +        struct timeval tv;
>>>> +        fd_set rfds;
>>>> +        int ret_sel;
>>>> +
>>>> +        close(fds[1]);
>>>> +        /* 0.1 second is okay, as the initiator will retry anyway */
>>>> +        do {
>>>> +            FD_ZERO(&rfds);
>>>> +            FD_SET(fds[0], &rfds);
>>>> +            tv.tv_sec = 0;
>>>> +            tv.tv_usec = 100000;
>>>> +            ret_sel = select(fds[0]+1, &rfds, NULL, NULL, &tv);
>>>> +        } while (ret_sel < 0 && errno == EINTR);
>>>> +        if (ret_sel <= 0) { /* error or timeout */
>>>> +            eprintf("timeout on redirect callback, terminating "
>>>> +                "child pid %d\n", pid);
>>>> +            kill(pid, SIGTERM);
>>>> +        }
>>>> +        do {
>>>> +            ret = waitpid(pid, &i, 0);
>>>> +        } while (ret < 0 && errno == EINTR);
>>>> +        if (ret < 0) {
>>>> +            eprintf("waitpid failed for: %s, %m\n", cmd);
>>>> +            close(fds[0]);
>>>> +            return ret;
>>>> +        }
>>>> +        if (ret_sel > 0) {
>>>> +            ret = read(fds[0], output, op_len);
>>>> +            if (ret < 0) {
>>>> +                eprintf("failed to get output from: %s\n", cmd);
>>>> +                close(fds[0]);
>>>> +                return ret;
>>>> +            }
>>>> +        }
>>>> +
>>>> +        if (callback)
>>>> +            callback(data, WEXITSTATUS(i));
>>>> +        close(fds[0]);
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +struct tgt_param {
>>>> +    int (*parse_func)(char *);
>>>> +    char *name;
>>>> +};
>>>> +
>>>> +static struct tgt_param params[64];
>>>> +
>>>> +int setup_param(char *name, int (*parser)(char *))
>>>> +{
>>>> +    int i;
>>>> +
>>>> +    for (i = 0; i < ARRAY_SIZE(params); i++)
>>>> +        if (!params[i].name)
>>>> +            break;
>>>> +
>>>> +    if (i < ARRAY_SIZE(params)) {
>>>> +        params[i].name = name;
>>>> +        params[i].parse_func = parser;
>>>> +
>>>> +        return 0;
>>>> +    } else
>>>> +        return -1;
>>>> +}
>>>> +
>>>> +int parse_params(char *name, char *p)
>>>> +{
>>>> +    int i;
>>>> +
>>>> +    for (i = 0; i < ARRAY_SIZE(params) && params[i].name; i++) {
>>>> +        if (!strcmp(name, params[i].name))
>>>> +            return params[i].parse_func(p);
>>>> +    }
>>>> +
>>>> +    fprintf(stderr, "'%s' is an unknown option\n", name);
>>>> +
>>>> +    return -1;
>>>> +}
>>>> +
>>>>   static void __attribute__((constructor)) target_constructor(void)
>>>>   {
>>>>       static int global_target_aids[DEFAULT_NR_ACCOUNT];
>>>> diff --git a/usr/tgtd.c b/usr/tgtd.c
>>>> index f985510..3ef7220 100644
>>>> --- a/usr/tgtd.c
>>>> +++ b/usr/tgtd.c
>>>> @@ -30,11 +30,9 @@
>>>>   #include <stdlib.h>
>>>>   #include <string.h>
>>>>   #include <unistd.h>
>>>> -#include <ctype.h>
>>>>   #include <sys/resource.h>
>>>>   #include <sys/epoll.h>
>>>>   #include <sys/types.h>
>>>> -#include <sys/wait.h>
>>>>   #include <sys/stat.h>
>>>>
>>>>   #include "list.h"
>>>> @@ -44,12 +42,10 @@
>>>>   #include "util.h"
>>>>
>>>>   unsigned long pagesize, pageshift;
>>>> +extern int ep_fd;
>>>>
>>>>   int system_active = 1;
>>>> -static int ep_fd;
>>>>   static char program_name[] = "tgtd";
>>>> -static LIST_HEAD(tgt_events_list);
>>>> -static LIST_HEAD(tgt_sched_events_list);
>>>>
>>>>   static struct option const long_options[] = {
>>>>       {"foreground", no_argument, 0, 'f'},
>>>> @@ -174,238 +170,6 @@ set_rlimit:
>>>>       return 0;
>>>>   }
>>>>
>>>> -int tgt_event_add(int fd, int events, event_handler_t handler, void
>>>> *data)
>>>> -{
>>>> -    struct epoll_event ev;
>>>> -    struct event_data *tev;
>>>> -    int err;
>>>> -
>>>> -    tev = zalloc(sizeof(*tev));
>>>> -    if (!tev)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    tev->data = data;
>>>> -    tev->handler = handler;
>>>> -    tev->fd = fd;
>>>> -
>>>> -    memset(&ev, 0, sizeof(ev));
>>>> -    ev.events = events;
>>>> -    ev.data.ptr = tev;
>>>> -    err = epoll_ctl(ep_fd, EPOLL_CTL_ADD, fd, &ev);
>>>> -    if (err) {
>>>> -        eprintf("Cannot add fd, %m\n");
>>>> -        free(tev);
>>>> -    } else
>>>> -        list_add(&tev->e_list, &tgt_events_list);
>>>> -
>>>> -    return err;
>>>> -}
>>>> -
>>>> -static struct event_data *tgt_event_lookup(int fd)
>>>> -{
>>>> -    struct event_data *tev;
>>>> -
>>>> -    list_for_each_entry(tev, &tgt_events_list, e_list) {
>>>> -        if (tev->fd == fd)
>>>> -            return tev;
>>>> -    }
>>>> -    return NULL;
>>>> -}
>>>> -
>>>> -void tgt_event_del(int fd)
>>>> -{
>>>> -    struct event_data *tev;
>>>> -    int ret;
>>>> -
>>>> -    tev = tgt_event_lookup(fd);
>>>> -    if (!tev) {
>>>> -        eprintf("Cannot find event %d\n", fd);
>>>> -        return;
>>>> -    }
>>>> -
>>>> -    ret = epoll_ctl(ep_fd, EPOLL_CTL_DEL, fd, NULL);
>>>> -    if (ret < 0)
>>>> -        eprintf("fail to remove epoll event, %s\n", strerror(errno));
>>>> -
>>>> -    list_del(&tev->e_list);
>>>> -    free(tev);
>>>> -}
>>>> -
>>>> -int tgt_event_modify(int fd, int events)
>>>> -{
>>>> -    struct epoll_event ev;
>>>> -    struct event_data *tev;
>>>> -
>>>> -    tev = tgt_event_lookup(fd);
>>>> -    if (!tev) {
>>>> -        eprintf("Cannot find event %d\n", fd);
>>>> -        return -EINVAL;
>>>> -    }
>>>> -
>>>> -    memset(&ev, 0, sizeof(ev));
>>>> -    ev.events = events;
>>>> -    ev.data.ptr = tev;
>>>> -
>>>> -    return epoll_ctl(ep_fd, EPOLL_CTL_MOD, fd, &ev);
>>>> -}
>>>> -
>>>> -void tgt_init_sched_event(struct event_data *evt,
>>>> -              sched_event_handler_t sched_handler, void *data)
>>>> -{
>>>> -    evt->sched_handler = sched_handler;
>>>> -    evt->scheduled = 0;
>>>> -    evt->data = data;
>>>> -    INIT_LIST_HEAD(&evt->e_list);
>>>> -}
>>>> -
>>>> -void tgt_add_sched_event(struct event_data *evt)
>>>> -{
>>>> -    if (!evt->scheduled) {
>>>> -        evt->scheduled = 1;
>>>> -        list_add_tail(&evt->e_list, &tgt_sched_events_list);
>>>> -    }
>>>> -}
>>>> -
>>>> -void tgt_remove_sched_event(struct event_data *evt)
>>>> -{
>>>> -    if (evt->scheduled) {
>>>> -        evt->scheduled = 0;
>>>> -        list_del_init(&evt->e_list);
>>>> -    }
>>>> -}
>>>> -
>>>> -/* strcpy, while eating multiple white spaces */
>>>> -void str_spacecpy(char **dest, const char *src)
>>>> -{
>>>> -    const char *s = src;
>>>> -    char *d = *dest;
>>>> -
>>>> -    while (*s) {
>>>> -        if (isspace(*s)) {
>>>> -            if (!*(s+1))
>>>> -                break;
>>>> -            if (isspace(*(s+1))) {
>>>> -                s++;
>>>> -                continue;
>>>> -            }
>>>> -        }
>>>> -        *d++ = *s++;
>>>> -    }
>>>> -    *d = '\0';
>>>> -}
>>>> -
>>>> -int call_program(const char *cmd, void (*callback)(void *data, int
>>>> result),
>>>> -        void *data, char *output, int op_len, int flags)
>>>> -{
>>>> -    pid_t pid;
>>>> -    int fds[2], ret, i;
>>>> -    char *pos, arg[256];
>>>> -    char *argv[sizeof(arg) / 2];
>>>> -
>>>> -    i = 0;
>>>> -    pos = arg;
>>>> -    str_spacecpy(&pos, cmd);
>>>> -    if (strchr(cmd, ' ')) {
>>>> -        while (pos != '\0')
>>>> -            argv[i++] = strsep(&pos, " ");
>>>> -    } else
>>>> -        argv[i++] = arg;
>>>> -    argv[i] =  NULL;
>>>> -
>>>> -    ret = pipe(fds);
>>>> -    if (ret < 0) {
>>>> -        eprintf("pipe create failed for %s, %m\n", cmd);
>>>> -        return ret;
>>>> -    }
>>>> -
>>>> -    dprintf("%s, pipe: %d %d\n", cmd, fds[0], fds[1]);
>>>> -
>>>> -    pid = fork();
>>>> -    if (pid < 0) {
>>>> -        eprintf("fork failed for: %s, %m\n", cmd);
>>>> -        close(fds[0]);
>>>> -        close(fds[1]);
>>>> -        return pid;
>>>> -    }
>>>> -
>>>> -    if (!pid) {
>>>> -        close(1);
>>>> -        ret = dup(fds[1]);
>>>> -        if (ret < 0) {
>>>> -            eprintf("dup failed for: %s, %m\n", cmd);
>>>> -            exit(-1);
>>>> -        }
>>>> -        close(fds[0]);
>>>> -        execv(argv[0], argv);
>>>> -
>>>> -        eprintf("execv failed for: %s, %m\n", cmd);
>>>> -        exit(-1);
>>>> -    } else {
>>>> -        struct timeval tv;
>>>> -        fd_set rfds;
>>>> -        int ret_sel;
>>>> -
>>>> -        close(fds[1]);
>>>> -        /* 0.1 second is okay, as the initiator will retry anyway */
>>>> -        do {
>>>> -            FD_ZERO(&rfds);
>>>> -            FD_SET(fds[0], &rfds);
>>>> -            tv.tv_sec = 0;
>>>> -            tv.tv_usec = 100000;
>>>> -            ret_sel = select(fds[0]+1, &rfds, NULL, NULL, &tv);
>>>> -        } while (ret_sel < 0 && errno == EINTR);
>>>> -        if (ret_sel <= 0) { /* error or timeout */
>>>> -            eprintf("timeout on redirect callback, terminating "
>>>> -                "child pid %d\n", pid);
>>>> -            kill(pid, SIGTERM);
>>>> -        }
>>>> -        do {
>>>> -            ret = waitpid(pid, &i, 0);
>>>> -        } while (ret < 0 && errno == EINTR);
>>>> -        if (ret < 0) {
>>>> -            eprintf("waitpid failed for: %s, %m\n", cmd);
>>>> -            close(fds[0]);
>>>> -            return ret;
>>>> -        }
>>>> -        if (ret_sel > 0) {
>>>> -            ret = read(fds[0], output, op_len);
>>>> -            if (ret < 0) {
>>>> -                eprintf("failed to get output from: %s\n", cmd);
>>>> -                close(fds[0]);
>>>> -                return ret;
>>>> -            }
>>>> -        }
>>>> -
>>>> -        if (callback)
>>>> -            callback(data, WEXITSTATUS(i));
>>>> -        close(fds[0]);
>>>> -    }
>>>> -
>>>> -    return 0;
>>>> -}
>>>> -
>>>> -static int tgt_exec_scheduled(void)
>>>> -{
>>>> -    struct list_head *last_sched;
>>>> -    struct event_data *tev, *tevn;
>>>> -    int work_remains = 0;
>>>> -
>>>> -    if (!list_empty(&tgt_sched_events_list)) {
>>>> -        /* execute only work scheduled till now */
>>>> -        last_sched = tgt_sched_events_list.prev;
>>>> -        list_for_each_entry_safe(tev, tevn, &tgt_sched_events_list,
>>>> -                     e_list) {
>>>> -            tgt_remove_sched_event(tev);
>>>> -            tev->sched_handler(tev);
>>>> -            if (&tev->e_list == last_sched)
>>>> -                break;
>>>> -        }
>>>> -        if (!list_empty(&tgt_sched_events_list))
>>>> -            work_remains = 1;
>>>> -    }
>>>> -    return work_remains;
>>>> -}
>>>> -
>>>>   static void event_loop(void)
>>>>   {
>>>>       int nevent, i, sched_remains, timeout;
>>>> @@ -471,44 +235,6 @@ static void lld_exit(void)
>>>>       }
>>>>   }
>>>>
>>>> -struct tgt_param {
>>>> -    int (*parse_func)(char *);
>>>> -    char *name;
>>>> -};
>>>> -
>>>> -static struct tgt_param params[64];
>>>> -
>>>> -int setup_param(char *name, int (*parser)(char *))
>>>> -{
>>>> -    int i;
>>>> -
>>>> -    for (i = 0; i < ARRAY_SIZE(params); i++)
>>>> -        if (!params[i].name)
>>>> -            break;
>>>> -
>>>> -    if (i < ARRAY_SIZE(params)) {
>>>> -        params[i].name = name;
>>>> -        params[i].parse_func = parser;
>>>> -
>>>> -        return 0;
>>>> -    } else
>>>> -        return -1;
>>>> -}
>>>> -
>>>> -static int parse_params(char *name, char *p)
>>>> -{
>>>> -    int i;
>>>> -
>>>> -    for (i = 0; i < ARRAY_SIZE(params) && params[i].name; i++) {
>>>> -        if (!strcmp(name, params[i].name))
>>>> -            return params[i].parse_func(p);
>>>> -    }
>>>> -
>>>> -    fprintf(stderr, "'%s' is an unknown option\n", name);
>>>> -
>>>> -    return -1;
>>>> -}
>>>> -
>>>>   int main(int argc, char **argv)
>>>>   {
>>>>       struct sigaction sa_old;
>>>> diff --git a/usr/tgtd.h b/usr/tgtd.h
>>>> index 484e6e9..0d4c6ae 100644
>>>> --- a/usr/tgtd.h
>>>> +++ b/usr/tgtd.h
>>>> @@ -295,6 +295,7 @@ extern void tgt_event_del(int fd);
>>>>
>>>>   extern void tgt_add_sched_event(struct event_data *evt);
>>>>   extern void tgt_remove_sched_event(struct event_data *evt);
>>>> +extern int tgt_exec_scheduled(void);
>>>>
>>>>   extern int tgt_event_modify(int fd, int events);
>>>>   extern int target_cmd_queue(int tid, struct scsi_cmd *cmd);
>>>> @@ -373,6 +374,7 @@ extern struct backingstore_template
>>>> *get_backingstore_template(const char *name)
>>>>   extern int lld_init_one(int lld_index);
>>>>
>>>>   extern int setup_param(char *name, int (*parser)(char *));
>>>> +extern int parse_params(char *name, char *p);
>>>>
>>>>   extern int bs_init(void);
>>>>
>>>>
>>
--
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