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>

6 files changed, 18 insertions, 7 deletions

diff --git a/fsdev/9p-marshal.h b/fsdev/9p-marshal.h
index c8823d878f..8f3babb60a 100644
--- a/fsdev/9p-marshal.h
+++ b/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
diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index c757c8099f..f2f7772c86 100644
--- a/fsdev/file-op-9p.h
+++ b/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
 
diff --git a/fsdev/qemu-fsdev-opts.c b/fsdev/qemu-fsdev-opts.c
index 7c31ffffaf..07a18c6e48 100644
--- a/fsdev/qemu-fsdev-opts.c
+++ b/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,
@@ -76,6 +78,9 @@ static QemuOptsList qemu_virtfs_opts = {
             .name = "readonly",
             .type = QEMU_OPT_BOOL,
         }, {
+            .name = "multidevs",
+            .type = QEMU_OPT_STRING,
+        }, {
             .name = "socket",
             .type = QEMU_OPT_STRING,
         }, {
diff --git a/fsdev/qemu-fsdev-throttle.c b/fsdev/qemu-fsdev-throttle.c
index fe1d76dc76..5c83a1cc09 100644
--- a/fsdev/qemu-fsdev-throttle.c
+++ b/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)
diff --git a/fsdev/qemu-fsdev-throttle.h b/fsdev/qemu-fsdev-throttle.h
index c98e2feab5..a21aecddc7 100644
--- a/fsdev/qemu-fsdev-throttle.h
+++ b/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 *);
 
diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c
index 077a8c4e2b..a9e069c0c7 100644
--- a/fsdev/qemu-fsdev.c
+++ b/fsdev/qemu-fsdev.c
@@ -58,6 +58,7 @@ static FsDriverTable FsDrivers[] = {
             "writeout",
             "fmode",
             "dmode",
+            "multidevs",
             "throttling.bps-total",
             "throttling.bps-read",
             "throttling.bps-write",