Add and document the quota_convert function which converts between the

old 32-bit and the new 64-bit formats.

1 files changed, 97 insertions, 2 deletions

diff --git a/lib/libutil/quotafile.c b/lib/libutil/quotafile.c
index 652d95a..ab57d66 100644
--- a/lib/libutil/quotafile.c
+++ b/lib/libutil/quotafile.c
@@ -255,9 +255,9 @@ quota_maxid(struct quotafile *qf)
 		return (0);
 	switch (qf->wordsize) {
 	case 32:
-		return (st.st_size / sizeof(struct dqblk32));
+		return (st.st_size / sizeof(struct dqblk32) - 1);
 	case 64:
-		return (st.st_size / sizeof(struct dqblk64) - 1);
+		return (st.st_size / sizeof(struct dqblk64) - 2);
 	default:
 		return (0);
 	}
@@ -494,3 +494,98 @@ quota_write_limits(struct quotafile *qf, struct dqblk *dqb, int id)
 	}
 	/* not reached */
 }
+
+/*
+ * Convert a quota file from one format to another.
+ */
+int
+quota_convert(struct quotafile *qf, int wordsize)
+{
+	struct quotafile *newqf;
+	struct dqhdr64 dqh;
+	struct dqblk dqblk;
+	struct group *grp;
+	int serrno, maxid, id, fd;
+
+	/*
+	 * Quotas must not be active and quotafile must be open
+	 * for reading and writing.
+	 */
+	if ((qf->accmode & O_RDWR) != O_RDWR || qf->fd == -1) {
+		errno = EBADF;
+		return (-1);
+	}
+	if ((wordsize != 32 && wordsize != 64) ||
+	     wordsize == qf->wordsize) {
+		errno = EINVAL;
+		return (-1);
+	}
+	maxid = quota_maxid(qf);
+	if ((newqf = calloc(1, sizeof(*qf))) == NULL) {
+		errno = ENOMEM;
+		return (-1);
+	}
+	*newqf = *qf;
+	snprintf(newqf->qfname, MAXPATHLEN + 1, "%s_%d.orig", qf->qfname,
+	    qf->wordsize);
+	if (rename(qf->qfname, newqf->qfname) < 0) {
+		free(newqf);
+		return (-1);
+	}
+	if ((newqf->fd = open(qf->qfname, O_RDWR|O_CREAT|O_TRUNC, 0)) < 0) {
+		serrno = errno;
+		goto error;
+	}
+	newqf->wordsize = wordsize;
+	if (wordsize == 64) {
+		memset(&dqh, 0, sizeof(dqh));
+		memcpy(dqh.dqh_magic, Q_DQHDR64_MAGIC, sizeof(dqh.dqh_magic));
+		dqh.dqh_version = htobe32(Q_DQHDR64_VERSION);
+		dqh.dqh_hdrlen = htobe32(sizeof(struct dqhdr64));
+		dqh.dqh_reclen = htobe32(sizeof(struct dqblk64));
+		if (write(newqf->fd, &dqh, sizeof(dqh)) != sizeof(dqh)) {
+			serrno = errno;
+			goto error;
+		}
+	}
+	grp = getgrnam(QUOTAGROUP);
+	fchown(newqf->fd, 0, grp ? grp->gr_gid : 0);
+	fchmod(newqf->fd, 0640);
+	for (id = 0; id <= maxid; id++) {
+		if ((quota_read(qf, &dqblk, id)) < 0)
+			break;
+		switch (newqf->wordsize) {
+		case 32:
+			if ((quota_write32(newqf, &dqblk, id)) < 0)
+				break;
+			continue;
+		case 64:
+			if ((quota_write64(newqf, &dqblk, id)) < 0)
+				break;
+			continue;
+		default:
+			errno = EINVAL;
+			break;
+		}
+	}
+	if (id < maxid) {
+		serrno = errno;
+		goto error;
+	}
+	/*
+	 * Update the passed in quotafile to reference the new file
+	 * of the converted format size.
+	 */
+	fd = qf->fd;
+	qf->fd = newqf->fd;
+	newqf->fd = fd;
+	qf->wordsize = newqf->wordsize;
+	quota_close(newqf);
+	return (0);
+error:
+	/* put back the original file */
+	(void) rename(newqf->qfname, qf->qfname);
+	quota_close(newqf);
+	errno = serrno;
+	return (-1);
+}