vol_id: fix sloppy error handling

[elogind.git] / extras / volume_id / volume_id / util.c

diff --git a/extras/volume_id/volume_id/util.c b/extras/volume_id/volume_id/util.c
index a145a8aa2f207c595f2334b9e0f22ec6661fd53f..62b96a36570a1dba38ce1cd2f838346c59237f27 100644 (file)
--- a/extras/volume_id/volume_id/util.c
+++ b/extras/volume_id/volume_id/util.c
@@ -114,12 +114,6 @@ void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t co
        id->label_raw_len = count;
 }
 
-static size_t my_strnlen(const char *s, size_t max) {
-    const char *p = s;
-    for (; *p && max--; ++p);
-    return(p - s);
-}
-
 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
 {
        unsigned int i;
@@ -127,7 +121,7 @@ void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t
        memcpy(id->label, buf, count);
 
        /* remove trailing whitespace */
-       i = my_strnlen(id->label, count);
+       i = strnlen(id->label, count);
        while (i--) {
                if (!isspace(id->label[i]))
                        break;
@@ -210,19 +204,30 @@ uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
        if (off + len <= SB_BUFFER_SIZE) {
                if (id->sbbuf == NULL) {
                        id->sbbuf = malloc(SB_BUFFER_SIZE);
-                       if (id->sbbuf == NULL)
+                       if (id->sbbuf == NULL) {
+                               dbg("error malloc");
                                return NULL;
+                       }
                }
 
                /* check if we need to read */
                if ((off + len) > id->sbbuf_len) {
                        dbg("read sbbuf len:0x%llx", (unsigned long long) (off + len));
-                       lseek(id->fd, 0, SEEK_SET);
+                       if (lseek(id->fd, 0, SEEK_SET) < 0) {
+                               dbg("lseek failed (%s)", strerror(errno));
+                               return NULL;
+                       }
                        buf_len = read(id->fd, id->sbbuf, off + len);
+                       if (buf_len < 0) {
+                               dbg("read failed (%s)", strerror(errno));
+                               return NULL;
+                       }
                        dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
                        id->sbbuf_len = buf_len;
-                       if (buf_len < off + len)
+                       if (buf_len < off + len) {
+                               dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
                                return NULL;
+                       }
                }
 
                return &(id->sbbuf[off]);
@@ -235,16 +240,24 @@ uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
                /* get seek buffer */
                if (id->seekbuf == NULL) {
                        id->seekbuf = malloc(SEEK_BUFFER_SIZE);
-                       if (id->seekbuf == NULL)
+                       if (id->seekbuf == NULL) {
+                               dbg("error malloc");
                                return NULL;
+                       }
                }
 
                /* check if we need to read */
                if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
                        dbg("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len);
-                       if (lseek(id->fd, off, SEEK_SET) == -1)
+                       if (lseek(id->fd, off, SEEK_SET) < 0) {
+                               dbg("lseek failed (%s)", strerror(errno));
                                return NULL;
+                       }
                        buf_len = read(id->fd, id->seekbuf, len);
+                       if (buf_len < 0) {
+                               dbg("read failed (%s)", strerror(errno));
+                               return NULL;
+                       }
                        dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
                        id->seekbuf_off = off;
                        id->seekbuf_len = buf_len;