From: "Dr. David Alan Gilbert"
The 'journal' is a shared block of RAM between QEMU and it's
fuse daemon. It's typically a shmfs file and it's specified as:
-device
vhost-user-fs-pci,chardev=char0,tag=myfs,cache-size=1G,versiontable=/dev/shm/mdvt1,journal=/dev/shm/journal1
It gets mapped into the PCI bar after the version table.
Signed-off-by: Dr. David Alan Gilbert
---
hw/virtio/vhost-user-fs.c | 35 --
hw/virtio/virtio-pci.c | 14 -
include/hw/virtio/vhost-user-fs.h | 4 +++
include/standard-headers/linux/virtio_fs.h | 1 +
4 files changed, 51 insertions(+), 3 deletions(-)
diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
index a39ecd3a16..b263f43c60 100644
--- a/hw/virtio/vhost-user-fs.c
+++ b/hw/virtio/vhost-user-fs.c
@@ -297,6 +297,7 @@ static void vuf_device_realize(DeviceState *dev, Error
**errp)
size_t len;
int ret;
int mdvtfd = -1;
+int journalfd = -1;
if (!fs->conf.chardev.chr) {
error_setg(errp, "missing chardev");
@@ -361,8 +362,31 @@ static void vuf_device_realize(DeviceState *dev, Error
**errp)
fs->mdvt_size = statbuf.st_size;
}
-fprintf(stderr, "%s: cachesize=%zd mdvt_size=%zd\n", __func__,
-fs->conf.cache_size, fs->mdvt_size);
+if (fs->conf.journalpath) {
+struct stat statbuf;
+
+journalfd = open(fs->conf.journalpath, O_RDWR);
+if (journalfd < 0) {
+error_setg_errno(errp, errno,
+ "Failed to open journal '%s'",
+ fs->conf.journalpath);
+
+close(mdvtfd);
+return;
+}
+if (fstat(journalfd, ) == -1) {
+error_setg_errno(errp, errno,
+ "Failed to stat journal '%s'",
+ fs->conf.journalpath);
+close(mdvtfd);
+close(journalfd);
+return;
+}
+
+fs->journal_size = statbuf.st_size;
+}
+fprintf(stderr, "%s: cachesize=%zd mdvt_size=%zd journal_size=%zd\n",
+__func__, fs->conf.cache_size, fs->mdvt_size, fs->journal_size);
/* We need a region with some host memory, 'ram' is the easiest */
memory_region_init_ram_nomigrate(>cache, OBJECT(vdev),
@@ -383,6 +407,12 @@ static void vuf_device_realize(DeviceState *dev, Error
**errp)
memory_region_set_readonly(>mdvt, true);
}
+if (journalfd) {
+memory_region_init_ram_from_fd(>journal, OBJECT(vdev),
+ "virtio-fs-journal",
+ fs->journal_size, true, journalfd, NULL);
+}
+
fs->vhost_user = vhost_user_init();
if (!fs->vhost_user) {
error_setg(errp, "failed to initialize vhost-user");
@@ -452,6 +482,7 @@ static Property vuf_properties[] = {
DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
DEFINE_PROP_SIZE("cache-size", VHostUserFS, conf.cache_size, 1ull << 30),
DEFINE_PROP_STRING("versiontable", VHostUserFS, conf.mdvtpath),
+DEFINE_PROP_STRING("journal", VHostUserFS, conf.journalpath),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index d8785b78bf..a46dd5a784 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -2687,10 +2687,12 @@ static void vhost_user_fs_pci_realize(VirtIOPCIProxy
*vpci_dev, Error **errp)
cachesize = memory_region_size(>vdev.cache);
/* PCIe bar needs to be a power of 2 */
-totalsize = pow2ceil(cachesize + dev->vdev.mdvt_size);
+totalsize = pow2ceil(cachesize + dev->vdev.mdvt_size +
+ dev->vdev.journal_size);
/* The bar starts with the data/DAX cache
* followed by the metadata cache.
+ * followed by the journal
*/
memory_region_init(>cachebar, OBJECT(vpci_dev),
"vhost-fs-pci-cachebar", totalsize);
@@ -2706,6 +2708,16 @@ static void vhost_user_fs_pci_realize(VirtIOPCIProxy
*vpci_dev, Error **errp)
VIRTIO_FS_PCI_SHMCAP_ID_VERTAB);
}
+if (dev->vdev.journal_size) {
+memory_region_add_subregion(>cachebar,
+cachesize + dev->vdev.mdvt_size,
+>vdev.journal);
+virtio_pci_add_shm_cap(vpci_dev, VIRTIO_FS_PCI_CACHE_BAR,
+ cachesize + dev->vdev.mdvt_size,
+ dev->vdev.journal_size,
+ VIRTIO_FS_PCI_SHMCAP_ID_JOURNAL);
+}
+
/* After 'realized' so the memory region exists */
pci_register_bar(_dev->pci_dev, VIRTIO_FS_PCI_CACHE_BAR,
PCI_BASE_ADDRESS_SPACE_MEMORY |
diff --git a/include/hw/virtio/vhost-user-fs.h
b/include/hw/virtio/vhost-user-fs.h
index 281ae0a52d..6d9f74a543 100644
--- a/include/hw/virtio/vhost-user-fs.h
+++ b/include/hw/virtio/vhost-user-fs.h
@@ -49,6 +49,7 @@ typedef
