A new fsdev parameter "readonly" is introduced to control accessing 9p export. readonly=on|off can be used to specify the access type. By default rw access is given.
Signed-off-by: M. Mohan Kumar <mo...@in.ibm.com> --- Changes from previous version V3: * Use opt_set_bool function to set readonly option * Change the flag from MS_READONLY to 9p specific Change from previous version V2: * QEMU_OPT_BOOL is used for readdonly parameter Changes from previous version: * Use "readonly" option instead of "access" * Change function return type to boolean where its needed fsdev/file-op-9p.h | 3 +- fsdev/qemu-fsdev.c | 12 +++++++++- fsdev/qemu-fsdev.h | 1 + hw/9pfs/virtio-9p-device.c | 3 ++ hw/9pfs/virtio-9p.c | 46 ++++++++++++++++++++++++++++++++++++++++++++ qemu-config.c | 7 ++++++ vl.c | 2 + 7 files changed, 71 insertions(+), 3 deletions(-) diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h index 33fb07f..b75290d 100644 --- a/fsdev/file-op-9p.h +++ b/fsdev/file-op-9p.h @@ -58,7 +58,8 @@ typedef struct extended_ops { } extended_ops; /* FsContext flag values */ -#define PATHNAME_FSCONTEXT 0x1 +#define PATHNAME_FSCONTEXT 0x1 +#define P9_RDONLY_EXPORT 0x2 /* cache flags */ #define V9FS_WRITETHROUGH_CACHE 0x1 diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c index d08ba9c..f8a8227 100644 --- a/fsdev/qemu-fsdev.c +++ b/fsdev/qemu-fsdev.c @@ -29,13 +29,13 @@ static FsTypeTable FsTypes[] = { int qemu_fsdev_add(QemuOpts *opts) { struct FsTypeListEntry *fsle; - int i; + int i, flags = 0; const char *fsdev_id = qemu_opts_id(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"); - + int rdonly = qemu_opt_get_bool(opts, "readonly", 0); if (!fsdev_id) { fprintf(stderr, "fsdev: No id specified\n"); @@ -76,6 +76,14 @@ int qemu_fsdev_add(QemuOpts *opts) fsle->fse.cache_flags = V9FS_WRITETHROUGH_CACHE; } } + if (rdonly) { + flags |= P9_RDONLY_EXPORT; + } else { + flags &= ~P9_RDONLY_EXPORT; + } + + fsle->fse.flags = flags; + QTAILQ_INSERT_TAIL(&fstype_entries, fsle, next); return 0; } diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h index 0f67880..2938eaf 100644 --- a/fsdev/qemu-fsdev.h +++ b/fsdev/qemu-fsdev.h @@ -44,6 +44,7 @@ typedef struct FsTypeEntry { char *security_model; int cache_flags; FileOperations *ops; + int flags; } FsTypeEntry; typedef struct FsTypeListEntry { diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c index 1846e36..336292c 100644 --- a/hw/9pfs/virtio-9p-device.c +++ b/hw/9pfs/virtio-9p-device.c @@ -125,6 +125,9 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf) s->tag_len = len; s->ctx.uid = -1; s->ctx.flags = 0; + if (fse->flags & P9_RDONLY_EXPORT) { + s->ctx.flags |= P9_RDONLY_EXPORT; + } s->ops = fse->ops; s->vdev.get_features = virtio_9p_get_features; diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c index 47ed2f1..9f15787 100644 --- a/hw/9pfs/virtio-9p.c +++ b/hw/9pfs/virtio-9p.c @@ -1271,6 +1271,11 @@ static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len) dst->size++; } +static inline bool is_ro_export(FsContext *fs_ctx) +{ + return fs_ctx->flags & P9_RDONLY_EXPORT; +} + static void v9fs_version(void *opaque) { V9fsPDU *pdu = opaque; @@ -1690,6 +1695,14 @@ static void v9fs_open(void *opaque) } else { flags = omode_to_uflags(mode); } + if (is_ro_export(&s->ctx)) { + if (mode & O_WRONLY || mode & O_RDWR || mode & O_APPEND) { + err = -EROFS; + goto out; + } else { + flags |= O_NOATIME; + } + } err = v9fs_co_open(pdu, fidp, flags); if (err < 0) { goto out; @@ -3301,6 +3314,33 @@ static void v9fs_op_not_supp(void *opaque) complete_pdu(pdu->s, pdu, -EOPNOTSUPP); } +static inline bool is_read_only_op(int id) +{ + switch (id) { + case P9_TREADDIR: + case P9_TSTATFS: + case P9_TGETATTR: + case P9_TXATTRWALK: + case P9_TLOCK: + case P9_TGETLOCK: + case P9_TREADLINK: + case P9_TVERSION: + case P9_TLOPEN: + case P9_TATTACH: + case P9_TSTAT: + case P9_TWALK: + case P9_TCLUNK: + case P9_TFSYNC: + case P9_TOPEN: + case P9_TREAD: + case P9_TAUTH: + case P9_TFLUSH: + return 1; + default: + return 0; + } +} + static void submit_pdu(V9fsState *s, V9fsPDU *pdu) { Coroutine *co; @@ -3312,6 +3352,12 @@ static void submit_pdu(V9fsState *s, V9fsPDU *pdu) } else { handler = pdu_co_handlers[pdu->id]; } + + if (is_ro_export(&s->ctx) && !is_read_only_op(pdu->id)) { + complete_pdu(s, pdu, -EROFS); + return; + } + co = qemu_coroutine_create(handler); qemu_coroutine_enter(co, pdu); } diff --git a/qemu-config.c b/qemu-config.c index b2ab0b2..5cad718 100644 --- a/qemu-config.c +++ b/qemu-config.c @@ -180,7 +180,11 @@ QemuOptsList qemu_fsdev_opts = { }, { .name = "cache", .type = QEMU_OPT_STRING, + }, { + .name = "readonly", + .type = QEMU_OPT_BOOL, }, + { /*End of list */ } }, }; @@ -205,6 +209,9 @@ QemuOptsList qemu_virtfs_opts = { }, { .name = "cache", .type = QEMU_OPT_STRING, + }, { + .name = "readonly", + .type = QEMU_OPT_BOOL, }, { /*End of list */ } diff --git a/vl.c b/vl.c index cab4002..04ffb26 100644 --- a/vl.c +++ b/vl.c @@ -2848,6 +2848,8 @@ int main(int argc, char **argv, char **envp) qemu_opt_set(fsdev, "security_model", qemu_opt_get(opts, "security_model")); + qemu_opt_set_bool(fsdev, "readonly", + qemu_opt_get_bool(opts, "readonly", 0)); device = qemu_opts_create(qemu_find_opts("device"), NULL, 0); qemu_opt_set(device, "driver", "virtio-9p-pci"); qemu_opt_set(device, "fsdev", -- 1.7.6