cache=writethrough implies the file are opened in the host with O_SYNC open flag
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
fsdev/file-op-9p.h | 1 +
fsdev/qemu-fsdev.c | 10 ++++++++--
fsdev/qemu-fsdev.h | 2 ++
hw/9pfs/virtio-9p-device.c | 6 ++++++
hw/9pfs/virtio-9p.c | 28 ++++++++++++++++++++--------
qemu-config.c | 6 ++++++
qemu-options.hx | 17 ++++++++++++-----
vl.c | 6 ++++++
8 files changed, 61 insertions(+), 15 deletions(-)
diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 1eda342..fbf9afb 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -54,6 +54,7 @@ typedef struct FsContext
char *fs_root;
SecModel fs_sm;
uid_t uid;
+ int open_flags;
struct xattr_operations **xops;
} FsContext;
diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c
index 0b33290..fccf011 100644
--- a/fsdev/qemu-fsdev.c
+++ b/fsdev/qemu-fsdev.c
@@ -33,6 +33,8 @@ int qemu_fsdev_add(QemuOpts *opts)
const char *fstype = qemu_opt_get(opts, "fstype");
const char *path = qemu_opt_get(opts, "path");
const char *sec_model = qemu_opt_get(opts, "security_model");
+ const char *cache = qemu_opt_get(opts, "cache");
+
if (!fsdev_id) {
fprintf(stderr, "fsdev: No id specified\n");
@@ -71,10 +73,14 @@ int qemu_fsdev_add(QemuOpts *opts)
fsle->fse.path = qemu_strdup(path);
fsle->fse.security_model = qemu_strdup(sec_model);
fsle->fse.ops = FsTypes[i].ops;
-
+ fsle->fse.cache_model = 0;
+ if (cache) {
+ if (!strcmp(cache, "writethrough")) {
+ fsle->fse.cache_model = V9FS_WRITETHROUGH_CACHE;
+ }
+ }
QTAILQ_INSERT_TAIL(&fstype_entries, fsle, next);
return 0;
-
}
FsTypeEntry *get_fsdev_fsentry(char *id)
diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h
index f9f08d3..8cc010b 100644
--- a/fsdev/qemu-fsdev.h
+++ b/fsdev/qemu-fsdev.h
@@ -34,6 +34,7 @@ typedef struct FsTypeTable {
FileOperations *ops;
} FsTypeTable;
+#define V9FS_WRITETHROUGH_CACHE 0x1
/*
* Structure to store the various fsdev's passed through command line.
*/
@@ -41,6 +42,7 @@ typedef struct FsTypeEntry {
char *fsdev_id;
char *path;
char *security_model;
+ int cache_model;
FileOperations *ops;
} FsTypeEntry;
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 4bec8bf..55edc45 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -114,6 +114,12 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf
*conf)
exit(1);
}
+ if (fse->cache_model & V9FS_WRITETHROUGH_CACHE) {
+ s->ctx.open_flags = O_SYNC;
+ } else {
+ s->ctx.open_flags = 0;
+ }
+
s->ctx.fs_root = qemu_strdup(fse->path);
len = strlen(conf->tag);
if (len > MAX_TAG_LEN) {
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 55aca93..9d1813e 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -80,6 +80,22 @@ void cred_init(FsCred *credp)
credp->fc_rdev = -1;
}
+static int get_dotl_openflags(V9fsState *s, int oflags)
+{
+ int flags;
+ /*
+ * Filter the client open flags
+ */
+ flags = s->ctx.open_flags;
+ flags |= oflags;
+ flags &= ~(O_NOCTTY | O_ASYNC | O_CREAT);
+ /*
+ * Ignore direct disk access hint until the server supports it.
+ */
+ flags &= ~O_DIRECT;
+ return flags;
+}
+
static void v9fs_string_init(V9fsString *str)
{
str->data = NULL;
@@ -1540,10 +1556,7 @@ static void v9fs_open(void *opaque)
err = offset;
} else {
if (s->proto_version == V9FS_PROTO_2000L) {
- flags = mode;
- flags &= ~(O_NOCTTY | O_ASYNC | O_CREAT);
- /* Ignore direct disk access hint until the server supports it. */
- flags &= ~O_DIRECT;
+ flags = get_dotl_openflags(s, mode);
} else {
flags = omode_to_uflags(mode);
}
@@ -1596,10 +1609,9 @@ static void v9fs_lcreate(void *opaque)
}
v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
- /* Ignore direct disk access hint until the server supports it. */
- flags &= ~O_DIRECT;
-
- err = v9fs_co_open2(pdu->s, fidp, fullname.data, gid, flags, mode);
+ flags = get_dotl_openflags(pdu->s, flags);
+ err = v9fs_co_open2(pdu->s, fidp, fullname.data, gid,
+ flags | O_CREAT, mode);
if (err < 0) {
goto out;
}
diff --git a/qemu-config.c b/qemu-config.c
index 5d7ffa2..1125fb3 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -170,6 +170,9 @@ QemuOptsList qemu_fsdev_opts = {
}, {
.name = "security_model",
.type = QEMU_OPT_STRING,
+ }, {
+ .name = "cache",
+ .type = QEMU_OPT_STRING,
},
{ /*End of list */ }
},
@@ -192,6 +195,9 @@ QemuOptsList qemu_virtfs_opts = {
}, {
.name = "security_model",
.type = QEMU_OPT_STRING,
+ }, {
+ .name = "cache",
+ .type = QEMU_OPT_STRING,
},
{ /*End of list */ }
diff --git a/qemu-options.hx b/qemu-options.hx
index 82e085a..4789fe4 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -486,7 +486,8 @@ ETEXI
DEFHEADING(File system options:)
DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
- "-fsdev local,id=id,path=path,security_model=[mapped|passthrough|none]\n",
+ "-fsdev local,id=id,path=path,security_model=[mapped|passthrough|none]\n"
+ " [,cache=writethrough]\n",
QEMU_ARCH_ALL)
STEXI
@@ -502,7 +503,7 @@ The specific Fstype will determine the applicable options.
Options to each backend are described below.
-@item -fsdev local ,id=@var{id} ,path=@var{path}
,security_model=@var{security_model}
+@item -fsdev local ,id=@var{id} ,path=@var{path}
,security_model=@var{security_model}[,cache=@var{cache}]
Create a file-system-"device" for local-filesystem.
@@ -513,13 +514,17 @@ Create a file-system-"device" for local-filesystem.
@option{security_model} specifies the security model to be followed.
@option{security_model} is required.
+@option{cache} specifies whether to skip the host page cache.
+@option{cache} is an optional argument.
+
@end table
ETEXI
DEFHEADING(Virtual File system pass-through options:)
DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
- "-virtfs
local,path=path,mount_tag=tag,security_model=[mapped|passthrough|none]\n",
+ "-virtfs
local,path=path,mount_tag=tag,security_model=[mapped|passthrough|none]\n"
+ " [,cache=writethrough]\n",
QEMU_ARCH_ALL)
STEXI
@@ -535,7 +540,7 @@ The specific Fstype will determine the applicable options.
Options to each backend are described below.
-@item -virtfs local ,path=@var{path} ,mount_tag=@var{mount_tag}
,security_model=@var{security_model}
+@item -virtfs local ,path=@var{path} ,mount_tag=@var{mount_tag}
,security_model=@var{security_model}[,cache=@var{cache}]
Create a Virtual file-system-pass through for local-filesystem.
@@ -546,10 +551,12 @@ Create a Virtual file-system-pass through for
local-filesystem.
@option{security_model} specifies the security model to be followed.
@option{security_model} is required.
-
@option{mount_tag} specifies the tag with which the exported file is mounted.
@option{mount_tag} is required.
+@option{cache} specifies whether to skip the host page cache.
+@option{cache} is an optional argument.
+
@end table
ETEXI
diff --git a/vl.c b/vl.c
index b362871..396a8db 100644
--- a/vl.c
+++ b/vl.c
@@ -2541,6 +2541,7 @@ int main(int argc, char **argv, char **envp)
case QEMU_OPTION_virtfs: {
QemuOpts *fsdev;
QemuOpts *device;
+ const char *cache;
olist = qemu_find_opts("virtfs");
if (!olist) {
@@ -2570,6 +2571,11 @@ int main(int argc, char **argv, char **envp)
qemu_opt_get(opts, "mount_tag"));
exit(1);
}
+
+ cache = qemu_opt_get(opts, "cache");
+ if (cache) {
+ qemu_opt_set(fsdev, "cache", cache);
+ }
qemu_opt_set(fsdev, "fstype", qemu_opt_get(opts, "fstype"));
qemu_opt_set(fsdev, "path", qemu_opt_get(opts, "path"));
qemu_opt_set(fsdev, "security_model",
--
1.7.4.1
