Commit 3625c739 authored by Markus Armbruster's avatar Markus Armbruster
Browse files

ivshmem-server: Don't overload POSIX shmem and file name 



Option -m NAME is interpreted as directory name if we can statfs() it
and its on hugetlbfs.  Else it's interpreted as POSIX shared memory
object name.  This is nuts.

Always interpret -m as directory.  Create new -M for POSIX shared
memory.  Last of -m or -M wins.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-4-git-send-email-armbru@redhat.com>
Reviewed-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
parent e3ad7296

contrib/ivshmem-server/ivshmem-server.c

+10 −46
Original line number Diff line number Diff line
@@ -12,9 +12,6 @@ 
#include <sys/mman.h>

#include <sys/socket.h>

#include <sys/un.h>

#ifdef CONFIG_LINUX

#include <sys/vfs.h>

#endif



#include "ivshmem-server.h"
@@ -257,7 +254,8 @@ ivshmem_server_ftruncate(int fd, unsigned shmsize) 
/* Init a new ivshmem server */

int

ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path,

                    const char *shm_path, size_t shm_size, unsigned n_vectors,

                    const char *shm_path, bool use_shm_open,

                    size_t shm_size, unsigned n_vectors,

                    bool verbose)

{

    int ret;
@@ -278,6 +276,7 @@ ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path, 
        return -1;

    }



    server->use_shm_open = use_shm_open;

    server->shm_size = shm_size;

    server->n_vectors = n_vectors;
@@ -286,31 +285,6 @@ ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path, 
    return 0;

}



#ifdef CONFIG_LINUX



#define HUGETLBFS_MAGIC       0x958458f6



static long gethugepagesize(const char *path)

{

    struct statfs fs;

    int ret;



    do {

        ret = statfs(path, &fs);

    } while (ret != 0 && errno == EINTR);



    if (ret != 0) {

        return -1;

    }



    if (fs.f_type != HUGETLBFS_MAGIC) {

        return -1;

    }



    return fs.f_bsize;

}

#endif



/* open shm, create and bind to the unix socket */

int

ivshmem_server_start(IvshmemServer *server)
@@ -319,27 +293,17 @@ ivshmem_server_start(IvshmemServer *server) 
    int shm_fd, sock_fd, ret;



    /* open shm file */

#ifdef CONFIG_LINUX

    long hpagesize;



    hpagesize = gethugepagesize(server->shm_path);

    if (hpagesize < 0 && errno != ENOENT) {

        IVSHMEM_SERVER_DEBUG(server, "cannot stat shm file %s: %s\n",

                             server->shm_path, strerror(errno));

    }



    if (hpagesize > 0) {

    if (server->use_shm_open) {

        IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n",

                             server->shm_path);

        shm_fd = shm_open(server->shm_path, O_CREAT | O_RDWR, S_IRWXU);

    } else {

        gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX", server->shm_path);

        IVSHMEM_SERVER_DEBUG(server, "Using hugepages: %s\n", server->shm_path);

        IVSHMEM_SERVER_DEBUG(server, "Using file-backed shared memory: %s\n",

                             server->shm_path);

        shm_fd = mkstemp(filename);

        unlink(filename);

        g_free(filename);

    } else

#endif

    {

        IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n",

                             server->shm_path);

        shm_fd = shm_open(server->shm_path, O_CREAT|O_RDWR, S_IRWXU);

    }



    if (shm_fd < 0) {

contrib/ivshmem-server/ivshmem-server.h

+3 −1
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ typedef struct IvshmemServer { 
    char unix_sock_path[PATH_MAX];   /**< path to unix socket */

    int sock_fd;                     /**< unix sock file descriptor */

    char shm_path[PATH_MAX];         /**< path to shm */

    bool use_shm_open;

    size_t shm_size;                 /**< size of shm */

    int shm_fd;                      /**< shm file descriptor */

    unsigned n_vectors;              /**< number of vectors */
@@ -89,7 +90,8 @@ typedef struct IvshmemServer { 
 */

int

ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path,

                    const char *shm_path, size_t shm_size, unsigned n_vectors,

                    const char *shm_path, bool use_shm_open,

                    size_t shm_size, unsigned n_vectors,

                    bool verbose);



/**

contrib/ivshmem-server/main.c

+10 −4
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ typedef struct IvshmemServerArgs { 
    const char *pid_file;

    const char *unix_socket_path;

    const char *shm_path;

    bool use_shm_open;

    uint64_t shm_size;

    unsigned n_vectors;

} IvshmemServerArgs;
@@ -44,8 +45,9 @@ ivshmem_server_usage(const char *progname) 
           "     default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n"

           "  -S <unix-socket-path>: path to the unix socket to listen to\n"

           "     default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n"

           "  -m <shm-path>: POSIX shared memory object name or a hugetlbfs mount point\n"

           "  -M <shm-name>: POSIX shared memory object to use\n"

           "     default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"

           "  -m <dir-name>: where to create shared memory\n"

           "  -l <size>: size of shared memory in bytes\n"

           "     suffixes K, M and G can be used, e.g. 1K means 1024\n"

           "     default %u\n"
@@ -69,7 +71,7 @@ ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[]) 
    unsigned long long v;

    Error *err = NULL;



    while ((c = getopt(argc, argv, "hvFp:S:m:l:n:")) != -1) {

    while ((c = getopt(argc, argv, "hvFp:S:m:M:l:n:")) != -1) {



        switch (c) {

        case 'h': /* help */
@@ -93,8 +95,10 @@ ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[]) 
            args->unix_socket_path = optarg;

            break;



        case 'm': /* shm path */

        case 'M': /* shm name */

        case 'm': /* dir name */

            args->shm_path = optarg;

            args->use_shm_open = c == 'M';

            break;



        case 'l': /* shm size */
@@ -190,6 +194,7 @@ main(int argc, char *argv[]) 
        .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,

        .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,

        .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,

        .use_shm_open = true,

        .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,

        .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,

    };
@@ -217,7 +222,8 @@ main(int argc, char *argv[]) 
    }



    /* init the ivshms structure */

    if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path,

    if (ivshmem_server_init(&server, args.unix_socket_path,

                            args.shm_path, args.use_shm_open,

                            args.shm_size, args.n_vectors, args.verbose) < 0) {

        fprintf(stderr, "cannot init server\n");

        goto err;

tests/ivshmem-test.c

+1 −1
Original line number Diff line number Diff line
@@ -294,7 +294,7 @@ static void test_ivshmem_server(bool msi) 
    guint64 end_time = g_get_monotonic_time() + 5 * G_TIME_SPAN_SECOND;



    memset(tmpshmem, 0x42, TMPSHMSIZE);

    ret = ivshmem_server_init(&server, tmpserver, tmpshm,

    ret = ivshmem_server_init(&server, tmpserver, tmpshm, true,

                              TMPSHMSIZE, nvectors,

                              g_test_verbose());

    g_assert_cmpint(ret, ==, 0);