diff options
| -rw-r--r-- | extras/mini-os/include/xenbus.h | 29 | ||||
| -rw-r--r-- | extras/mini-os/xenbus/xenbus.c | 103 |
2 files changed, 104 insertions, 28 deletions
diff --git a/extras/mini-os/include/xenbus.h b/extras/mini-os/include/xenbus.h index 485f2e48d6..4bf35ce8fb 100644 --- a/extras/mini-os/include/xenbus.h +++ b/extras/mini-os/include/xenbus.h @@ -1,34 +1,51 @@ #ifndef XENBUS_H__ #define XENBUS_H__ +typedef unsigned long xenbus_transaction_t; +#define XBT_NIL ((xenbus_transaction_t)0) + /* Initialize the XenBus system. */ void init_xenbus(void); /* Read the value associated with a path. Returns a malloc'd error string on failure and sets *value to NULL. On success, *value is set to a malloc'd copy of the value. */ -char *xenbus_read(const char *path, char **value); +char *xenbus_read(xenbus_transaction_t xbt, const char *path, char **value); /* Associates a value with a path. Returns a malloc'd error string on failure. */ -char *xenbus_write(const char *path, const char *value); +char *xenbus_write(xenbus_transaction_t xbt, const char *path, const char *value); /* Removes the value associated with a path. Returns a malloc'd error string on failure. */ -char *xenbus_rm(const char *path); +char *xenbus_rm(xenbus_transaction_t xbt, const char *path); /* List the contents of a directory. Returns a malloc'd error string on failure and sets *contents to NULL. On success, *contents is set to a malloc'd array of pointers to malloc'd strings. The array is NULL terminated. May block. */ -char *xenbus_ls(const char *prefix, char ***contents); +char *xenbus_ls(xenbus_transaction_t xbt, const char *prefix, char ***contents); /* Reads permissions associated with a path. Returns a malloc'd error string on failure and sets *value to NULL. On success, *value is set to a malloc'd copy of the value. */ -char *xenbus_get_perms(const char *path, char **value); +char *xenbus_get_perms(xenbus_transaction_t xbt, const char *path, char **value); /* Sets the permissions associated with a path. Returns a malloc'd error string on failure. */ -char *xenbus_set_perms(const char *path, domid_t dom, char perm); +char *xenbus_set_perms(xenbus_transaction_t xbt, const char *path, domid_t dom, char perm); + +/* Start a xenbus transaction. Returns the transaction in xbt on + success or a malloc'd error string otherwise. */ +char *xenbus_transaction_start(xenbus_transaction_t *xbt); + +/* End a xenbus transaction. Returns a malloc'd error string if it + fails. abort says whether the transaction should be aborted. + Returns 1 in *retry iff the transaction should be retried. */ +char *xenbus_transaction_end(xenbus_transaction_t, int abort, + int *retry); + +/* Read path and parse it as an integer. Returns -1 on error. */ +int xenbus_read_integer(char *path); + #endif /* XENBUS_H__ */ diff --git a/extras/mini-os/xenbus/xenbus.c b/extras/mini-os/xenbus/xenbus.c index 6c56a87dc7..bf04bac1ce 100644 --- a/extras/mini-os/xenbus/xenbus.c +++ b/extras/mini-os/xenbus/xenbus.c @@ -174,7 +174,7 @@ void init_xenbus(void) create_thread("xenstore", xenbus_thread_func, NULL); DEBUG("buf at %p.\n", xenstore_buf); err = bind_evtchn(start_info.store_evtchn, - xenbus_evtchn_handler); + xenbus_evtchn_handler); DEBUG("xenbus on irq %d\n", err); } @@ -187,8 +187,8 @@ struct write_req { by xenbus as if sent atomically. The header is added automatically, using type %type, req_id %req_id, and trans_id %trans_id. */ -static void xb_write(int type, int req_id, int trans_id, - const struct write_req *req, int nr_reqs) +static void xb_write(int type, int req_id, xenbus_transaction_t trans_id, + const struct write_req *req, int nr_reqs) { XENSTORE_RING_IDX prod; int r; @@ -266,9 +266,9 @@ static void xb_write(int type, int req_id, int trans_id, freed by the caller. */ static struct xsd_sockmsg * xenbus_msg_reply(int type, - int trans, - struct write_req *io, - int nr_reqs) + xenbus_transaction_t trans, + struct write_req *io, + int nr_reqs) { int id; DEFINE_WAIT(w); @@ -322,14 +322,14 @@ static void xenbus_debug_msg(const char *msg) /* List the contents of a directory. Returns a malloc()ed array of pointers to malloc()ed strings. The array is NULL terminated. May block. */ -char *xenbus_ls(const char *pre, char ***contents) +char *xenbus_ls(xenbus_transaction_t xbt, const char *pre, char ***contents) { struct xsd_sockmsg *reply, *repmsg; struct write_req req[] = { { pre, strlen(pre)+1 } }; int nr_elems, x, i; char **res; - repmsg = xenbus_msg_reply(XS_DIRECTORY, 0, req, ARRAY_SIZE(req)); + repmsg = xenbus_msg_reply(XS_DIRECTORY, xbt, req, ARRAY_SIZE(req)); char *msg = errmsg(repmsg); if (msg) { *contents = NULL; @@ -351,12 +351,12 @@ char *xenbus_ls(const char *pre, char ***contents) return NULL; } -char *xenbus_read(const char *path, char **value) +char *xenbus_read(xenbus_transaction_t xbt, const char *path, char **value) { struct write_req req[] = { {path, strlen(path) + 1} }; struct xsd_sockmsg *rep; char *res; - rep = xenbus_msg_reply(XS_READ, 0, req, ARRAY_SIZE(req)); + rep = xenbus_msg_reply(XS_READ, xbt, req, ARRAY_SIZE(req)); char *msg = errmsg(rep); if (msg) { *value = NULL; @@ -370,14 +370,14 @@ char *xenbus_read(const char *path, char **value) return NULL; } -char *xenbus_write(const char *path, const char *value) +char *xenbus_write(xenbus_transaction_t xbt, const char *path, const char *value) { struct write_req req[] = { {path, strlen(path) + 1}, {value, strlen(value) + 1}, }; struct xsd_sockmsg *rep; - rep = xenbus_msg_reply(XS_WRITE, 0, req, ARRAY_SIZE(req)); + rep = xenbus_msg_reply(XS_WRITE, xbt, req, ARRAY_SIZE(req)); char *msg = errmsg(rep); if (msg) return msg; @@ -385,11 +385,11 @@ char *xenbus_write(const char *path, const char *value) return NULL; } -char *xenbus_rm(const char *path) +char *xenbus_rm(xenbus_transaction_t xbt, const char *path) { struct write_req req[] = { {path, strlen(path) + 1} }; struct xsd_sockmsg *rep; - rep = xenbus_msg_reply(XS_RM, 0, req, ARRAY_SIZE(req)); + rep = xenbus_msg_reply(XS_RM, xbt, req, ARRAY_SIZE(req)); char *msg = errmsg(rep); if (msg) return msg; @@ -397,12 +397,12 @@ char *xenbus_rm(const char *path) return NULL; } -char *xenbus_get_perms(const char *path, char **value) +char *xenbus_get_perms(xenbus_transaction_t xbt, const char *path, char **value) { struct write_req req[] = { {path, strlen(path) + 1} }; struct xsd_sockmsg *rep; char *res; - rep = xenbus_msg_reply(XS_GET_PERMS, 0, req, ARRAY_SIZE(req)); + rep = xenbus_msg_reply(XS_GET_PERMS, xbt, req, ARRAY_SIZE(req)); char *msg = errmsg(rep); if (msg) { *value = NULL; @@ -417,7 +417,7 @@ char *xenbus_get_perms(const char *path, char **value) } #define PERM_MAX_SIZE 32 -char *xenbus_set_perms(const char *path, domid_t dom, char perm) +char *xenbus_set_perms(xenbus_transaction_t xbt, const char *path, domid_t dom, char perm) { char value[PERM_MAX_SIZE]; snprintf(value, PERM_MAX_SIZE, "%c%hu", perm, dom); @@ -426,7 +426,7 @@ char *xenbus_set_perms(const char *path, domid_t dom, char perm) {value, strlen(value) + 1}, }; struct xsd_sockmsg *rep; - rep = xenbus_msg_reply(XS_SET_PERMS, 0, req, ARRAY_SIZE(req)); + rep = xenbus_msg_reply(XS_SET_PERMS, xbt, req, ARRAY_SIZE(req)); char *msg = errmsg(rep); if (msg) return msg; @@ -434,13 +434,72 @@ char *xenbus_set_perms(const char *path, domid_t dom, char perm) return NULL; } +char *xenbus_transaction_start(xenbus_transaction_t *xbt) +{ + /* xenstored becomes angry if you send a length 0 message, so just + shove a nul terminator on the end */ + struct write_req req = { "", 1}; + struct xsd_sockmsg *rep; + char *err; + + rep = xenbus_msg_reply(XS_TRANSACTION_START, 0, &req, 1); + err = errmsg(rep); + if (err) + return err; + sscanf((char *)(rep + 1), "%u", xbt); + free(rep); + return NULL; +} + +char * +xenbus_transaction_end(xenbus_transaction_t t, int abort, int *retry) +{ + struct xsd_sockmsg *rep; + struct write_req req; + char *err; + + *retry = 0; + + req.data = abort ? "F" : "T"; + req.len = 2; + rep = xenbus_msg_reply(XS_TRANSACTION_END, t, &req, 1); + err = errmsg(rep); + if (err) { + if (!strcmp(err, "EAGAIN")) { + *retry = 1; + free(err); + return NULL; + } else { + return err; + } + } + free(rep); + return NULL; +} + +int xenbus_read_integer(char *path) +{ + char *res, *buf; + int t; + + res = xenbus_read(XBT_NIL, path, &buf); + if (res) { + printk("Failed to read %s.\n", path); + free(res); + return -1; + } + sscanf(buf, "%d", &t); + free(buf); + return t; +} + static void do_ls_test(const char *pre) { char **dirs; int x; DEBUG("ls %s...\n", pre); - char *msg = xenbus_ls(pre, &dirs); + char *msg = xenbus_ls(XBT_NIL, pre, &dirs); if (msg) { DEBUG("Error in xenbus ls: %s\n", msg); free(msg); @@ -458,7 +517,7 @@ static void do_read_test(const char *path) { char *res; DEBUG("Read %s...\n", path); - char *msg = xenbus_read(path, &res); + char *msg = xenbus_read(XBT_NIL, path, &res); if (msg) { DEBUG("Error in xenbus read: %s\n", msg); free(msg); @@ -471,7 +530,7 @@ static void do_read_test(const char *path) static void do_write_test(const char *path, const char *val) { DEBUG("Write %s to %s...\n", val, path); - char *msg = xenbus_write(path, val); + char *msg = xenbus_write(XBT_NIL, path, val); if (msg) { DEBUG("Result %s\n", msg); free(msg); @@ -483,7 +542,7 @@ static void do_write_test(const char *path, const char *val) static void do_rm_test(const char *path) { DEBUG("rm %s...\n", path); - char *msg = xenbus_rm(path); + char *msg = xenbus_rm(XBT_NIL, path); if (msg) { DEBUG("Result %s\n", msg); free(msg); |