LU-4724 hsm: Safe copytool event logging

[fs/lustre-release.git] / lustre / utils / liblustreapi_hsm.c

diff --git a/lustre/utils/liblustreapi_hsm.c b/lustre/utils/liblustreapi_hsm.c
index 3f1b8b9..4831ad4 100644 (file)
--- a/lustre/utils/liblustreapi_hsm.c
+++ b/lustre/utils/liblustreapi_hsm.c
@@ -113,7 +113,7 @@ enum ct_event {
 };
 
 /* initialized in llapi_hsm_register_event_fifo() */
-FILE *llapi_hsm_event_fp;
+int llapi_hsm_event_fd = -1;
 
 static inline const char *llapi_hsm_ct_ev2str(int type)
 {
@@ -173,12 +173,14 @@ int llapi_hsm_write_json_event(struct llapi_json_item_list **event)
 {
        int                             rc;
        char                            time_string[40];
+       char                            json_buf[PIPE_BUF];
+       FILE                            *buf_file;
        time_t                          event_time = time(0);
        struct tm                       time_components;
        struct llapi_json_item_list     *json_items;
 
-       /* Noop unless the event fp was initialized */
-       if (llapi_hsm_event_fp == NULL)
+       /* Noop unless the event fd was initialized */
+       if (llapi_hsm_event_fd < 0)
                return 0;
 
        if (event == NULL || *event == NULL)
@@ -203,21 +205,24 @@ int llapi_hsm_write_json_event(struct llapi_json_item_list **event)
                return rc;
        }
 
-       rc = llapi_json_write_list(event, llapi_hsm_event_fp);
-       if (rc < 0) {
-               /* Ignore write failures due to missing reader. */
-               if (rc == -EPIPE)
-                       return 0;
+       buf_file = fmemopen(json_buf, sizeof(json_buf), "w");
+       if (buf_file == NULL)
+               return -errno;
 
-               /* Skip llapi_error() here because there's no point
-                * in creating a JSON-formatted error message about
-                * failing to write a JSON-formatted message.
-                */
-               fprintf(stderr,
-                       "\nFATAL ERROR IN llapi_hsm_write_list(): rc %d", rc);
+       rc = llapi_json_write_list(event, buf_file);
+       if (rc < 0) {
+               fclose(buf_file);
                return rc;
        }
 
+       fclose(buf_file);
+
+       if (write(llapi_hsm_event_fd, json_buf, strlen(json_buf)) < 0) {
+               /* Ignore write failures due to missing reader. */
+               if (errno != EPIPE)
+                       return -errno;
+       }
+
        return 0;
 }
 
@@ -443,7 +448,7 @@ out_free:
  */
 int llapi_hsm_register_event_fifo(char *path)
 {
-       int read_fd, write_fd;
+       int read_fd;
        struct stat statbuf;
 
        /* Create the FIFO if necessary. */
@@ -476,8 +481,8 @@ int llapi_hsm_register_event_fifo(char *path)
 
        /* Open the FIFO for writes, but don't block on waiting
         * for a reader. */
-       write_fd = open(path, O_WRONLY | O_NONBLOCK);
-       if (write_fd < 0) {
+       llapi_hsm_event_fd = open(path, O_WRONLY | O_NONBLOCK);
+       if (llapi_hsm_event_fd < 0) {
                llapi_error(LLAPI_MSG_ERROR, errno,
                            "cannot open(%s) for write", path);
                return -errno;
@@ -488,19 +493,9 @@ int llapi_hsm_register_event_fifo(char *path)
         * events are lost. NOTE: Only one reader at a time! */
        close(read_fd);
 
-       llapi_hsm_event_fp = fdopen(write_fd, "w");
-       if (llapi_hsm_event_fp == NULL) {
-               llapi_error(LLAPI_MSG_ERROR, errno,
-                           "cannot fdopen(%s) for write", path);
-               return -errno;
-       }
-
        /* Ignore SIGPIPEs -- can occur if the reader goes away. */
        signal(SIGPIPE, SIG_IGN);
 
-       /* Don't buffer the event stream. */
-       setbuf(llapi_hsm_event_fp, NULL);
-
        return 0;
 }
 
@@ -514,16 +509,16 @@ int llapi_hsm_register_event_fifo(char *path)
  */
 int llapi_hsm_unregister_event_fifo(char *path)
 {
-       /* Noop unless the event fp was initialized */
-       if (llapi_hsm_event_fp == NULL)
+       /* Noop unless the event fd was initialized */
+       if (llapi_hsm_event_fd < 0)
                return 0;
 
-       if (fclose(llapi_hsm_event_fp) != 0)
+       if (close(llapi_hsm_event_fd) < 0)
                return -errno;
 
        unlink(path);
 
-       llapi_hsm_event_fp = NULL;
+       llapi_hsm_event_fd = -1;
 
        return 0;
 }
@@ -550,8 +545,8 @@ void llapi_hsm_log_error(enum llapi_message_level level, int _rc,
        va_list                         args2;
        struct llapi_json_item_list     *json_items;
 
-       /* Noop unless the event fp was initialized */
-       if (llapi_hsm_event_fp == NULL)
+       /* Noop unless the event fd was initialized */
+       if (llapi_hsm_event_fd < 0)
                return;
 
        rc = llapi_json_init_list(&json_items);