tdb2: remove looping for write

On normal files, pwrite and write should never return short except on error.
As we never create sparse files, so any short write is an I/O error.

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 999922b12e517c63be16ce1b20d7d22d077f9acc..bdf86b676738d2fa1c067e23f4361a4a8d54650d 100644 (file)
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -206,25 +206,6 @@ tdb_off_t tdb_read_off(struct tdb_context *tdb, tdb_off_t off)
        return ret;
 }
 
-/* Even on files, we can get partial writes due to signals. */
-bool tdb_pwrite_all(int fd, const void *buf, size_t len, tdb_off_t off)
-{
-       while (len) {
-               ssize_t ret;
-               ret = pwrite(fd, buf, len, off);
-               if (ret < 0)
-                       return false;
-               if (ret == 0) {
-                       errno = ENOSPC;
-                       return false;
-               }
-               buf = (char *)buf + ret;
-               off += ret;
-               len -= ret;
-       }
-       return true;
-}
-
 /* write a lump of data at a specified offset */
 static int tdb_write(struct tdb_context *tdb, tdb_off_t off, 
                     const void *buf, tdb_len_t len)
@@ -246,10 +227,17 @@ static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
        if (tdb->map_ptr) {
                memcpy(off + (char *)tdb->map_ptr, buf, len);
        } else {
-               if (!tdb_pwrite_all(tdb->fd, buf, len, off)) {
+               ssize_t ret;
+               ret = pwrite(tdb->fd, buf, len, off);
+               if (ret < len) {
+                       /* This shouldn't happen: we avoid sparse files. */
+                       if (ret >= 0)
+                               errno = ENOSPC;
+
                        tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-                                  "tdb_write failed at %zu len=%zu (%s)",
-                                  (size_t)off, (size_t)len, strerror(errno));
+                                  "tdb_write: %zi at %zu len=%zu (%s)",
+                                  ret, (size_t)off, (size_t)len,
+                                  strerror(errno));
                        return -1;
                }
        }
@@ -361,10 +349,15 @@ static int fill(struct tdb_context *tdb,
 {
        while (len) {
                size_t n = len > size ? size : len;
+               ssize_t ret = pwrite(tdb->fd, buf, n, off);
+               if (ret < n) {
+                       if (ret >= 0)
+                               errno = ENOSPC;
 
-               if (!tdb_pwrite_all(tdb->fd, buf, n, off)) {
                        tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-                                "fill write failed: giving up!");
+                                  "fill failed: %zi at %zu len=%zu (%s)",
+                                  ret, (size_t)off, (size_t)len,
+                                  strerror(errno));
                        return -1;
                }
                len -= n;

diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index 1092f171427cbbd097b9738db7fad6ceedb2c066..75e49c8313fcee17d40f8fe01ecd7953c7305fb3 100644 (file)
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -474,9 +474,6 @@ tdb_off_t tdb_find_nonzero_off(struct tdb_context *tdb,
 tdb_off_t tdb_find_zero_off(struct tdb_context *tdb, tdb_off_t off,
                            uint64_t num);
 
-/* Even on files, we can get partial writes due to signals. */
-bool tdb_pwrite_all(int fd, const void *buf, size_t len, tdb_off_t off);
-
 /* Allocate and make a copy of some offset. */
 void *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len);
 

diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index e3b579d0f259ad94498fe740f84bef7dc52d9d2b..1aa3baa46c24471033af359dba192ab82e3747a3 100644 (file)
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -101,6 +101,7 @@ static int tdb_new_database(struct tdb_context *tdb,
        /* We make it up in memory, then write it out if not internal */
        struct new_database newdb;
        unsigned int magic_len;
+       ssize_t rlen;
 
        /* Fill in the header */
        newdb.hdr.version = TDB_VERSION;
@@ -153,10 +154,13 @@ static int tdb_new_database(struct tdb_context *tdb,
        if (ftruncate(tdb->fd, 0) == -1)
                return -1;
 
-       if (!tdb_pwrite_all(tdb->fd, &newdb, sizeof(newdb), 0)) {
+       rlen = write(tdb->fd, &newdb, sizeof(newdb));
+       if (rlen != sizeof(newdb)) {
+               if (rlen >= 0)
+                       errno = ENOSPC;
                tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-                          "tdb_new_database: failed to write: %s",
-                          strerror(errno));
+                          "tdb_new_database: %zi writing header: %s",
+                          rlen, strerror(errno));
                return -1;
        }
        return 0;