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-rw-r--r--hw/9pfs/cofs.c377
1 files changed, 377 insertions, 0 deletions
diff --git a/hw/9pfs/cofs.c b/hw/9pfs/cofs.c
new file mode 100644
index 000000000..9d0adc2e7
--- /dev/null
+++ b/hw/9pfs/cofs.c
@@ -0,0 +1,377 @@
+/*
+ * 9p backend
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+/*
+ * Not so fast! You might want to read the 9p developer docs first:
+ * https://wiki.qemu.org/Documentation/9p
+ */
+
+#include "qemu/osdep.h"
+#include "fsdev/qemu-fsdev.h"
+#include "qemu/thread.h"
+#include "qemu/coroutine.h"
+#include "qemu/main-loop.h"
+#include "coth.h"
+
+static ssize_t __readlink(V9fsState *s, V9fsPath *path, V9fsString *buf)
+{
+ ssize_t len, maxlen = PATH_MAX;
+
+ buf->data = g_malloc(PATH_MAX);
+ for (;;) {
+ len = s->ops->readlink(&s->ctx, path, buf->data, maxlen);
+ if (len < 0) {
+ g_free(buf->data);
+ buf->data = NULL;
+ buf->size = 0;
+ break;
+ } else if (len == maxlen) {
+ /*
+ * We dodn't have space to put the NULL or we have more
+ * to read. Increase the size and try again
+ */
+ maxlen *= 2;
+ g_free(buf->data);
+ buf->data = g_malloc(maxlen);
+ continue;
+ }
+ /*
+ * Null terminate the readlink output
+ */
+ buf->data[len] = '\0';
+ buf->size = len;
+ break;
+ }
+ return len;
+}
+
+int coroutine_fn v9fs_co_readlink(V9fsPDU *pdu, V9fsPath *path, V9fsString *buf)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = __readlink(s, path, buf);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_statfs(V9fsPDU *pdu, V9fsPath *path,
+ struct statfs *stbuf)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->statfs(&s->ctx, path, stbuf);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_chmod(V9fsPDU *pdu, V9fsPath *path, mode_t mode)
+{
+ int err;
+ FsCred cred;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ cred_init(&cred);
+ cred.fc_mode = mode;
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->chmod(&s->ctx, path, &cred);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_utimensat(V9fsPDU *pdu, V9fsPath *path,
+ struct timespec times[2])
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->utimensat(&s->ctx, path, times);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_chown(V9fsPDU *pdu, V9fsPath *path, uid_t uid,
+ gid_t gid)
+{
+ int err;
+ FsCred cred;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ cred_init(&cred);
+ cred.fc_uid = uid;
+ cred.fc_gid = gid;
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->chown(&s->ctx, path, &cred);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_truncate(V9fsPDU *pdu, V9fsPath *path, off_t size)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->truncate(&s->ctx, path, size);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_mknod(V9fsPDU *pdu, V9fsFidState *fidp,
+ V9fsString *name, uid_t uid, gid_t gid,
+ dev_t dev, mode_t mode, struct stat *stbuf)
+{
+ int err;
+ V9fsPath path;
+ FsCred cred;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ cred_init(&cred);
+ cred.fc_uid = uid;
+ cred.fc_gid = gid;
+ cred.fc_mode = mode;
+ cred.fc_rdev = dev;
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->mknod(&s->ctx, &fidp->path, name->data, &cred);
+ if (err < 0) {
+ err = -errno;
+ } else {
+ v9fs_path_init(&path);
+ err = v9fs_name_to_path(s, &fidp->path, name->data, &path);
+ if (!err) {
+ err = s->ops->lstat(&s->ctx, &path, stbuf);
+ if (err < 0) {
+ err = -errno;
+ }
+ }
+ v9fs_path_free(&path);
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+/* Only works with path name based fid */
+int coroutine_fn v9fs_co_remove(V9fsPDU *pdu, V9fsPath *path)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->remove(&s->ctx, path->data);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+int coroutine_fn v9fs_co_unlinkat(V9fsPDU *pdu, V9fsPath *path,
+ V9fsString *name, int flags)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->unlinkat(&s->ctx, path, name->data, flags);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+/* Only work with path name based fid */
+int coroutine_fn v9fs_co_rename(V9fsPDU *pdu, V9fsPath *oldpath,
+ V9fsPath *newpath)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->rename(&s->ctx, oldpath->data, newpath->data);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ return err;
+}
+
+int coroutine_fn v9fs_co_renameat(V9fsPDU *pdu, V9fsPath *olddirpath,
+ V9fsString *oldname, V9fsPath *newdirpath,
+ V9fsString *newname)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->renameat(&s->ctx, olddirpath, oldname->data,
+ newdirpath, newname->data);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ return err;
+}
+
+int coroutine_fn v9fs_co_symlink(V9fsPDU *pdu, V9fsFidState *dfidp,
+ V9fsString *name, const char *oldpath,
+ gid_t gid, struct stat *stbuf)
+{
+ int err;
+ FsCred cred;
+ V9fsPath path;
+ V9fsState *s = pdu->s;
+
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ cred_init(&cred);
+ cred.fc_uid = dfidp->uid;
+ cred.fc_gid = gid;
+ cred.fc_mode = 0777;
+ v9fs_path_read_lock(s);
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->symlink(&s->ctx, oldpath, &dfidp->path,
+ name->data, &cred);
+ if (err < 0) {
+ err = -errno;
+ } else {
+ v9fs_path_init(&path);
+ err = v9fs_name_to_path(s, &dfidp->path, name->data, &path);
+ if (!err) {
+ err = s->ops->lstat(&s->ctx, &path, stbuf);
+ if (err < 0) {
+ err = -errno;
+ }
+ }
+ v9fs_path_free(&path);
+ }
+ });
+ v9fs_path_unlock(s);
+ return err;
+}
+
+/*
+ * For path name based fid we don't block. So we can
+ * directly call the fs driver ops.
+ */
+int coroutine_fn v9fs_co_name_to_path(V9fsPDU *pdu, V9fsPath *dirpath,
+ const char *name, V9fsPath *path)
+{
+ int err;
+ V9fsState *s = pdu->s;
+
+ if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
+ err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
+ if (err < 0) {
+ err = -errno;
+ }
+ } else {
+ if (v9fs_request_cancelled(pdu)) {
+ return -EINTR;
+ }
+ v9fs_co_run_in_worker(
+ {
+ err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
+ if (err < 0) {
+ err = -errno;
+ }
+ });
+ }
+ return err;
+}