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Re: [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX s
From: |
Marc-André Lureau |
Subject: |
Re: [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name |
Date: |
Wed, 9 Mar 2016 13:44:54 +0100 |
Hi
On Mon, Mar 7, 2016 at 8:25 PM, Markus Armbruster <address@hidden> wrote:
> 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: Markus Armbruster <address@hidden>
> ---
I don't see why the last should win is a good idea, see attached patch
for a possible solution, also changing a few comments. Feel free to
squash it in this patch or include it in your series.
Reviewed-by: Marc-André Lureau <address@hidden>
> contrib/ivshmem-server/ivshmem-server.c | 56
> ++++++---------------------------
> contrib/ivshmem-server/ivshmem-server.h | 4 ++-
> contrib/ivshmem-server/main.c | 15 +++++++--
> tests/ivshmem-test.c | 2 +-
> 4 files changed, 27 insertions(+), 50 deletions(-)
>
> diff --git a/contrib/ivshmem-server/ivshmem-server.c
> b/contrib/ivshmem-server/ivshmem-server.c
> index bfd0fad..41aee35 100644
> --- a/contrib/ivshmem-server/ivshmem-server.c
> +++ b/contrib/ivshmem-server/ivshmem-server.c
> @@ -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) {
> diff --git a/contrib/ivshmem-server/ivshmem-server.h
> b/contrib/ivshmem-server/ivshmem-server.h
> index e9de8a3..3851639 100644
> --- a/contrib/ivshmem-server/ivshmem-server.h
> +++ b/contrib/ivshmem-server/ivshmem-server.h
> @@ -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);
>
> /**
> diff --git a/contrib/ivshmem-server/main.c b/contrib/ivshmem-server/main.c
> index e9b4388..2795db5 100644
> --- a/contrib/ivshmem-server/main.c
> +++ b/contrib/ivshmem-server/main.c
> @@ -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 <name>: POSIX shared memory object to use\n"
> " default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"
> + " -m <dirname>: 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"
> @@ -76,6 +78,7 @@ ivshmem_server_parse_args(IvshmemServerArgs *args, int
> argc, char *argv[])
> "p:" /* pid_file */
> "S:" /* unix_socket_path */
> "m:" /* shm_path */
> + "M:" /* shm_path */
> "l:" /* shm_size */
> "n:" /* n_vectors */
> )) != -1) {
> @@ -102,8 +105,14 @@ ivshmem_server_parse_args(IvshmemServerArgs *args, int
> argc, char *argv[])
> args->unix_socket_path = optarg;
> break;
>
> + case 'M': /* shm_path */
> + args->shm_path = optarg;
> + args->use_shm_open = true;
> + break;
> +
> case 'm': /* shm_path */
> args->shm_path = optarg;
> + args->use_shm_open = false;
> break;
>
> case 'l': /* shm_size */
> @@ -199,6 +208,7 @@ 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,
> };
> @@ -226,7 +236,8 @@ 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;
> diff --git a/tests/ivshmem-test.c b/tests/ivshmem-test.c
> index e184c67..4efa433 100644
> --- a/tests/ivshmem-test.c
> +++ b/tests/ivshmem-test.c
> @@ -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);
> --
> 2.4.3
>
>
--
Marc-André Lureau
0001-ivshmem-server-expect-either-m-or-M.patch
Description: Text Data
- [Qemu-devel] [PATCH v2 21/42] ivshmem: Clean up MSI-X conditions, (continued)
- [Qemu-devel] [PATCH v2 21/42] ivshmem: Clean up MSI-X conditions, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 03/42] target-ppc: Document TOCTTOU in hugepage support, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 06/42] qemu-doc: Fix ivshmem huge page example, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 35/42] ivshmem: Inline check_shm_size() into its only caller, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 20/42] ivshmem: Clean up register callbacks, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name, Markus Armbruster, 2016/03/07
- Re: [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name,
Marc-André Lureau <=
[Qemu-devel] [PATCH v2 16/42] ivshmem: Drop ivshmem_event() stub, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 23/42] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 24/42] ivshmem: Simplify rejection of invalid peer ID from server, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 36/42] qdev: New DEFINE_PROP_ON_OFF_AUTO, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 25/42] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 40/42] ivshmem: Drop ivshmem property x-memdev, Markus Armbruster, 2016/03/07