git » libjio » commit 4d14be7

diff --git a/libjio/common.c b/libjio/common.c
index c85278f..02f5f4a 100644
--- a/libjio/common.c
+++ b/libjio/common.c
@@ -98,6 +98,49 @@ ssize_t spwrite(int fd, const void *buf, size_t count, off_t offset)
 	return count;
 }
 
+/** Like writev() but either fails, or return a complete write.
+ * Note that, as opposed to writev() it WILL MODIFY iov, in particular the
+ * iov_len fields. */
+ssize_t swritev(int fd, struct iovec *iov, int iovcnt)
+{
+	int i;
+	ssize_t rv, c, t;
+	size_t total;
+
+	total = 0;
+	for (i = 0; i < iovcnt; i++)
+		total += iov[i].iov_len;
+
+	c = 0;
+	while (c < total) {
+		rv = writev(fd, iov, iovcnt);
+
+		if (rv == total)
+			return total;
+		else if (rv < 0)
+			return rv;
+
+		/* incomplete write, advance iov and try again */
+		c += rv;
+		t = 0;
+		for (i = 0; i < iovcnt; i++) {
+			if (t + iov[i].iov_len > rv) {
+				iov[i].iov_base = (unsigned char *)
+					iov[i].iov_base + rv - t;
+				iov[i].iov_len -= rv - t;
+				break;
+			} else {
+				t += iov[i].iov_len;
+			}
+		}
+
+		iovcnt -= i;
+		iov = iov + i;
+	}
+
+	return c;
+}
+
 /** Store in jdir the default journal directory path of the given filename */
 int get_jdir(const char *filename, char *jdir)
 {
diff --git a/libjio/common.h b/libjio/common.h
index 512355a..71ccc49 100644
--- a/libjio/common.h
+++ b/libjio/common.h
@@ -8,6 +8,7 @@
 
 #include <sys/types.h>	/* for ssize_t and off_t */
 #include <stdint.h>	/* for uint*_t */
+#include <sys/uio.h>	/* for struct iovec */
 
 #include "libjio.h"	/* for struct jfs */
 #include "fiu-local.h"	/* for fault injection functions */
@@ -72,6 +73,7 @@ struct jfs {
 off_t plockf(int fd, int cmd, off_t offset, off_t len);
 ssize_t spread(int fd, void *buf, size_t count, off_t offset);
 ssize_t spwrite(int fd, const void *buf, size_t count, off_t offset);
+ssize_t swritev(int fd, struct iovec *iov, int iovcnt);
 int get_jdir(const char *filename, char *jdir);
 void get_jtfile(struct jfs *fs, unsigned int tid, char *jtfile);
 uint64_t ntohll(uint64_t x);
diff --git a/libjio/journal.c b/libjio/journal.c
index 353d848..51c63ea 100644
--- a/libjio/journal.c
+++ b/libjio/journal.c
@@ -212,6 +212,7 @@ struct journal_op *journal_new(struct jfs *fs, unsigned int flags)
 	char *name = NULL;
 	struct journal_op *jop;
 	struct on_disk_hdr hdr;
+	struct iovec iov[1];
 
 	jop = malloc(sizeof(struct journal_op));
 	if (jop == NULL)
@@ -235,7 +236,6 @@ struct journal_op *journal_new(struct jfs *fs, unsigned int flags)
 	jop->fd = fd;
 	jop->numops = 0;
 	jop->name = name;
-	jop->curpos = 0;
 	jop->csum = 0;
 	jop->fs = fs;
 
@@ -248,13 +248,14 @@ struct journal_op *journal_new(struct jfs *fs, unsigned int flags)
 	hdr.ver = 1;
 	hdr.trans_id = id;
 	hdr.flags = flags;
-
 	hdr_hton(&hdr);
-	rv = spwrite(fd, &hdr, sizeof(hdr), 0);
+
+	iov[0].iov_base = (unsigned char *) &hdr;
+	iov[0].iov_len = sizeof(hdr);
+	rv = swritev(fd, iov, 1);
 	if (rv != sizeof(hdr))
 		goto unlink_error;
 
-	jop->curpos = sizeof(hdr);
 	jop->csum = checksum_buf(jop->csum, (unsigned char *) &hdr,
 			sizeof(hdr));
 
@@ -280,29 +281,28 @@ int journal_add_op(struct journal_op *jop, unsigned char *buf, size_t len,
 {
 	ssize_t rv;
 	struct on_disk_ophdr ophdr;
+	struct iovec iov[2];
 
-	/* save the operation's header, */
 	ophdr.len = len;
 	ophdr.offset = offset;
-
 	ophdr_hton(&ophdr);
-	rv = spwrite(jop->fd, &ophdr, sizeof(ophdr), jop->curpos);
-	if (rv != sizeof(ophdr))
-		goto error;
 
-	fiu_exit_on("jio/commit/tf_ophdr");
-
-	jop->curpos += sizeof(ophdr);
+	iov[0].iov_base = (unsigned char *) &ophdr;
+	iov[0].iov_len = sizeof(ophdr);
 	jop->csum = checksum_buf(jop->csum, (unsigned char *) &ophdr,
 			sizeof(ophdr));
 
-	/* and save it to the disk */
-	rv = spwrite(jop->fd, buf, len, jop->curpos);
-	if (rv != len)
+	iov[1].iov_base = buf;
+	iov[1].iov_len = len;
+	jop->csum = checksum_buf(jop->csum, buf, len);
+
+	fiu_exit_on("jio/commit/tf_pre_addop");
+
+	rv = swritev(jop->fd, iov, 2);
+	if (rv != sizeof(ophdr) + len)
 		goto error;
 
-	jop->curpos += len;
-	jop->csum = checksum_buf(jop->csum, buf, len);
+	fiu_exit_on("jio/commit/tf_addop");
 
 	jop->numops++;
 
@@ -327,27 +327,26 @@ int journal_commit(struct journal_op *jop)
 	ssize_t rv;
 	struct on_disk_ophdr ophdr;
 	struct on_disk_trailer trailer;
+	struct iovec iov[2];
 
 	/* write the empty ophdr to mark there are no more operations, and
 	 * then the trailer */
 	ophdr.len = 0;
 	ophdr.offset = 0;
-
 	ophdr_hton(&ophdr);
-	rv = spwrite(jop->fd, &ophdr, sizeof(ophdr), jop->curpos);
-	if (rv != sizeof(ophdr))
-		goto error;
-
-	jop->curpos += sizeof(ophdr);
+	iov[0].iov_base = (unsigned char *) &ophdr;
+	iov[0].iov_len = sizeof(ophdr);
 	jop->csum = checksum_buf(jop->csum, (unsigned char *) &ophdr,
 			sizeof(ophdr));
 
 	trailer.checksum = jop->csum;
 	trailer.numops = jop->numops;
-
 	trailer_hton(&trailer);
-	rv = spwrite(jop->fd, &trailer, sizeof(trailer), jop->curpos);
-	if (rv != sizeof(trailer))
+	iov[1].iov_base = (unsigned char *) &trailer;
+	iov[1].iov_len = sizeof(trailer);
+
+	rv = swritev(jop->fd, iov, 2);
+	if (rv != sizeof(ophdr) + sizeof(trailer))
 		goto error;
 
 	/* this is a simple but efficient optimization: instead of doing
@@ -381,10 +380,9 @@ int journal_free(struct journal_op *jop)
 		/* we do not want to leave a possibly complete transaction
 		 * file around when the transaction was not commited and the
 		 * unlink failed, so we attempt to truncate it, and if that
-		 * fails we corrupt the checksum as a last resort */
+		 * fails we corrupt the header as a last resort */
 		if (ftruncate(jop->fd, 0) != 0) {
-			if (pwrite(jop->fd, "\0\0\0\0", 4, jop->curpos - 4)
-					!= 4)
+			if (pwrite(jop->fd, "\0\0\0\0", 4, 0) != 4)
 				goto exit;
 			if (fdatasync(jop->fd) != 0)
 				goto exit;
diff --git a/libjio/journal.h b/libjio/journal.h
index 80060c2..5f7acd6 100644
--- a/libjio/journal.h
+++ b/libjio/journal.h
@@ -11,7 +11,6 @@ struct journal_op {
 	int fd;
 	int numops;
 	char *name;
-	off_t curpos;
 	uint32_t csum;
 	struct jfs *fs;
 };
diff --git a/tests/behaviour/t_corruption.py b/tests/behaviour/t_corruption.py
index 1524d36..4d228ab 100644
--- a/tests/behaviour/t_corruption.py
+++ b/tests/behaviour/t_corruption.py
@@ -27,8 +27,8 @@ def test_c01():
 	n = run_with_tmp(f1)
 	assert content(n) == ''
 	tc = open(transpath(n, 1)).read()
-	# flip just one bit in the middle byte
-	pos = len(tc) / 2
+	# flip just one bit in the transaction data
+	pos = DHS + DOHS + len(c) / 2
 	tc = tc[:pos] + \
 		chr((ord(tc[pos]) & 0xFE) | (~ ord(tc[pos]) & 0x1) & 0xFF) + \
 		tc[pos + 1:]
diff --git a/tests/behaviour/t_fi.py b/tests/behaviour/t_fi.py
index 7490a08..6c36d40 100644
--- a/tests/behaviour/t_fi.py
+++ b/tests/behaviour/t_fi.py
@@ -65,12 +65,12 @@ def test_f03():
 	cleanup(n)
 
 def test_f04():
-	"fail jio/commit/tf_ophdr"
+	"fail jio/commit/tf_pre_addop"
 	c = gencontent()
 
 	def f1(f, jf):
-		fiu.enable_external("jio/commit/tf_ophdr",
-				gen_ret_after(1, 0, 1))
+		fiu.enable_external("jio/commit/tf_pre_addop",
+				gen_ret_seq((0, 1)))
 		t = jf.new_trans()
 		t.add(c, 0)
 		t.add(c, len(c) + 200)
@@ -78,7 +78,7 @@ def test_f04():
 
 	n = run_with_tmp(f1)
 
-	assert len(content(transpath(n, 1))) == DHS + DOHS + len(c) + DOHS
+	assert len(content(transpath(n, 1))) == DHS + DOHS + len(c)
 	assert content(n) == ''
 	fsck_verify(n, broken = 1)
 	assert content(n) == ''
diff --git a/tests/behaviour/tf.py b/tests/behaviour/tf.py
index 7cf4d61..ad793ea 100644
--- a/tests/behaviour/tf.py
+++ b/tests/behaviour/tf.py
@@ -226,6 +226,20 @@ def gen_ret_after(n, notyet, itstime):
 		return itstime
 	return newf
 
+def gen_ret_seq(seq):
+	"""Returns a function that each time it is called returns a value of
+	the given sequence, in order. When the sequence is exhausted, returns
+	the last value."""
+	it = iter(seq)
+	last = [0]
+	def newf(*args, **kwargs):
+		try:
+			r = it.next()
+			last[0] = r
+			return r
+		except StopIteration:
+			return last[0]
+	return newf
 
 def autorun(module, specific_test = None):
 	"Runs all the functions in the given module that begin with 'test'."