Merge remote-tracking branch 'remotes/gkurz/tags/9p-next-2019-10-10' …

…into staging

The most notable change is that we now detect cross-device setups in the
host since it may cause inode number collision and mayhem in the guest.
A new fsdev property is added for the user to choose the appropriate
policy to handle that: either remap all inode numbers or fail I/Os to
another host device or just print out a warning (default behaviour).

This is also my last PR as _active_ maintainer of 9pfs.

# gpg: Signature made Thu 10 Oct 2019 12:14:07 BST
# gpg:                using RSA key B4828BAF943140CEF2A3491071D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>" [full]
# gpg:                 aka "Gregory Kurz <gregory.kurz@free.fr>" [full]
# gpg:                 aka "[jpeg image of size 3330]" [full]
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3  4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/9p-next-2019-10-10:
  MAINTAINERS: Downgrade status of virtio-9p to "Odd Fixes"
  9p: Use variable length suffixes for inode remapping
  9p: stat_to_qid: implement slow path
  9p: Added virtfs option 'multidevs=remap|forbid|warn'
  9p: Treat multiple devices on one export as an error
  fsdev: Add return value to fsdev_throttle_parse_opts()
  9p: Simplify error path of v9fs_device_realize_common()
  9p: unsigned type for type, version, path

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

MAINTAINERS

@@ -1517,7 +1517,7 @@ F: tests/virtio-balloon-test.c
 
 virtio-9p
 M: Greg Kurz <groug@kaod.org>
-S: Supported
+S: Odd Fixes
 F: hw/9pfs/
 X: hw/9pfs/xen-9p*
 F: fsdev/

fsdev/9p-marshal.h

@@ -9,9 +9,9 @@ typedef struct V9fsString
 
 typedef struct V9fsQID
 {
-    int8_t type;
-    int32_t version;
-    int64_t path;
+    uint8_t type;
+    uint32_t version;
+    uint64_t path;
 } V9fsQID;
 
 typedef struct V9fsStat

fsdev/file-op-9p.h

@@ -59,6 +59,11 @@ typedef struct ExtendedOps {
 #define V9FS_RDONLY                 0x00000040
 #define V9FS_PROXY_SOCK_FD          0x00000080
 #define V9FS_PROXY_SOCK_NAME        0x00000100
+/*
+ * multidevs option (either one of the two applies exclusively)
+ */
+#define V9FS_REMAP_INODES           0x00000200
+#define V9FS_FORBID_MULTIDEVS       0x00000400
 
 #define V9FS_SEC_MASK               0x0000003C
 

fsdev/qemu-fsdev-opts.c

@@ -31,7 +31,9 @@ static QemuOptsList qemu_fsdev_opts = {
         }, {
             .name = "readonly",
             .type = QEMU_OPT_BOOL,
-
+        }, {
+            .name = "multidevs",
+            .type = QEMU_OPT_STRING,
         }, {
             .name = "socket",
             .type = QEMU_OPT_STRING,
@@ -75,6 +77,9 @@ static QemuOptsList qemu_virtfs_opts = {
         }, {
             .name = "readonly",
             .type = QEMU_OPT_BOOL,
+        }, {
+            .name = "multidevs",
+            .type = QEMU_OPT_STRING,
         }, {
             .name = "socket",
             .type = QEMU_OPT_STRING,

fsdev/qemu-fsdev-throttle.c

@@ -31,7 +31,7 @@ static void fsdev_throttle_write_timer_cb(void *opaque)
     qemu_co_enter_next(&fst->throttled_reqs[true], NULL);
 }
 
-void fsdev_throttle_parse_opts(QemuOpts *opts, FsThrottle *fst, Error **errp)
+int fsdev_throttle_parse_opts(QemuOpts *opts, FsThrottle *fst, Error **errp)
 {
     throttle_config_init(&fst->cfg);
     fst->cfg.buckets[THROTTLE_BPS_TOTAL].avg =
@@ -75,7 +75,7 @@ void fsdev_throttle_parse_opts(QemuOpts *opts, FsThrottle *fst, Error **errp)
     fst->cfg.op_size =
         qemu_opt_get_number(opts, "throttling.iops-size", 0);
 
-    throttle_is_valid(&fst->cfg, errp);
+    return throttle_is_valid(&fst->cfg, errp) ? 0 : -1;
 }
 
 void fsdev_throttle_init(FsThrottle *fst)

fsdev/qemu-fsdev-throttle.h

@@ -26,7 +26,7 @@ typedef struct FsThrottle {
     CoQueue      throttled_reqs[2];
 } FsThrottle;
 
-void fsdev_throttle_parse_opts(QemuOpts *, FsThrottle *, Error **);
+int fsdev_throttle_parse_opts(QemuOpts *, FsThrottle *, Error **);
 
 void fsdev_throttle_init(FsThrottle *);
 

fsdev/qemu-fsdev.c

@@ -58,6 +58,7 @@ static FsDriverTable FsDrivers[] = {
             "writeout",
             "fmode",
             "dmode",
+            "multidevs",
             "throttling.bps-total",
             "throttling.bps-read",
             "throttling.bps-write",

hw/9pfs/9p-local.c

@@ -1465,6 +1465,10 @@ static void local_cleanup(FsContext *ctx)
 {
     LocalData *data = ctx->private;
 
+    if (!data) {
+        return;
+    }
+
     close(data->mountfd);
     g_free(data);
 }
@@ -1479,6 +1483,7 @@ static int local_parse_opts(QemuOpts *opts, FsDriverEntry *fse, Error **errp)
 {
     const char *sec_model = qemu_opt_get(opts, "security_model");
     const char *path = qemu_opt_get(opts, "path");
+    const char *multidevs = qemu_opt_get(opts, "multidevs");
     Error *local_err = NULL;
 
     if (!sec_model) {
@@ -1502,13 +1507,32 @@ static int local_parse_opts(QemuOpts *opts, FsDriverEntry *fse, Error **errp)
         return -1;
     }
 
+    if (multidevs) {
+        if (!strcmp(multidevs, "remap")) {
+            fse->export_flags &= ~V9FS_FORBID_MULTIDEVS;
+            fse->export_flags |= V9FS_REMAP_INODES;
+        } else if (!strcmp(multidevs, "forbid")) {
+            fse->export_flags &= ~V9FS_REMAP_INODES;
+            fse->export_flags |= V9FS_FORBID_MULTIDEVS;
+        } else if (!strcmp(multidevs, "warn")) {
+            fse->export_flags &= ~V9FS_FORBID_MULTIDEVS;
+            fse->export_flags &= ~V9FS_REMAP_INODES;
+        } else {
+            error_setg(&local_err, "invalid multidevs property '%s'",
+                       multidevs);
+            error_append_hint(&local_err, "Valid options are: multidevs="
+                              "[remap|forbid|warn]\n");
+            error_propagate(errp, local_err);
+            return -1;
+        }
+    }
+
     if (!path) {
         error_setg(errp, "path property not set");
         return -1;
     }
 
-    fsdev_throttle_parse_opts(opts, &fse->fst, &local_err);
-    if (local_err) {
+    if (fsdev_throttle_parse_opts(opts, &fse->fst, &local_err)) {
         error_propagate_prepend(errp, local_err,
                                 "invalid throttle configuration: ");
         return -1;

hw/9pfs/9p-proxy.c

@@ -1185,6 +1185,10 @@ static void proxy_cleanup(FsContext *ctx)
 {
     V9fsProxy *proxy = ctx->private;
 
+    if (!proxy) {
+        return;
+    }
+
     g_free(proxy->out_iovec.iov_base);
     g_free(proxy->in_iovec.iov_base);
     if (ctx->export_flags & V9FS_PROXY_SOCK_NAME) {