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

ronnie sahlberg ronniesahlberg at gmail.com
Sat Aug 10 11:37:23 CEST 2013


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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