Write CPU endianess to transaction log header and check it's correct when reading.

--HG--
branch : HEAD

diff --git a/src/lib-index/mail-transaction-log-file.c b/src/lib-index/mail-transaction-log-file.c
index 15860534a70cf7ffe8bd0ad17b4e8444ebde069b..149c5a9cd16c4a1b5e2e05ab1819b80319b497f0 100644 (file)
--- a/src/lib-index/mail-transaction-log-file.c
+++ b/src/lib-index/mail-transaction-log-file.c
@@ -180,6 +180,9 @@ mail_transaction_log_init_hdr(struct mail_transaction_log *log,
        hdr->hdr_size = sizeof(struct mail_transaction_log_header);
        hdr->indexid = log->index->indexid;
        hdr->create_stamp = ioloop_time;
+#ifndef WORDS_BIGENDIAN
+       hdr->compat_flags |= MAIL_INDEX_COMPAT_LITTLE_ENDIAN;
+#endif
 
        if (index->fd != -1) {
                /* not creating index - make sure we have latest header */
@@ -345,6 +348,27 @@ void mail_transaction_log_file_unlock(struct mail_transaction_log_file *file)
        file_unlock(&file->file_lock);
 }
 
+static ssize_t
+mail_transaction_log_file_read_header(struct mail_transaction_log_file *file)
+{
+       ssize_t pos;
+       int ret;
+
+       memset(&file->hdr, 0, sizeof(file->hdr));
+
+        /* try to read the whole header, but it's not necessarily an error to
+          read less since the older versions of the log format could be
+          smaller. */
+        pos = 0;
+       do {
+               ret = pread(file->fd, PTR_OFFSET(&file->hdr, pos),
+                           sizeof(file->hdr) - pos, pos);
+               if (ret > 0)
+                       pos += ret;
+       } while (ret > 0 && pos < (ssize_t)sizeof(file->hdr));
+       return ret < 0 ? -1 : pos;
+}
+
 static int
 mail_transaction_log_file_read_hdr(struct mail_transaction_log_file *file,
                                   bool ignore_estale)
@@ -357,24 +381,40 @@ mail_transaction_log_file_read_hdr(struct mail_transaction_log_file *file,
        if (file->corrupted)
                return 0;
 
-       ret = pread_full(file->fd, &file->hdr, sizeof(file->hdr), 0);
+       ret = mail_transaction_log_file_read_header(file);
        if (ret < 0) {
                 if (errno != ESTALE || !ignore_estale) {
                         mail_index_file_set_syscall_error(file->log->index,
                                                           file->filepath,
-                                                          "pread_full()");
+                                                          "pread()");
                 }
                return -1;
        }
-       if (ret == 0) {
+       if (file->hdr.major_version != MAIL_TRANSACTION_LOG_MAJOR_VERSION) {
+               /* incompatible version - fix silently */
+               return 0;
+       }
+       if (ret < MAIL_TRANSACTION_LOG_HEADER_MIN_SIZE) {
                mail_transaction_log_file_set_corrupted(file,
                        "unexpected end of file while reading header");
                return 0;
        }
 
-       if (file->hdr.major_version != MAIL_TRANSACTION_LOG_MAJOR_VERSION) {
-               /* incompatible version - fix silently */
-               return 0;
+       if (file->hdr.minor_version >= 2 || file->hdr.major_version > 1) {
+               /* we have compatibility flags */
+               enum mail_index_header_compat_flags compat_flags = 0;
+
+#ifndef WORDS_BIGENDIAN
+               compat_flags |= MAIL_INDEX_COMPAT_LITTLE_ENDIAN;
+#endif
+               if (file->hdr.compat_flags != compat_flags) {
+                       /* architecture change */
+                       mail_index_set_error(file->log->index,
+                                            "Rebuilding index file %s: "
+                                            "CPU architecture changed",
+                                            file->log->index->filepath);
+                       return 0;
+               }
        }
        if (file->hdr.hdr_size < MAIL_TRANSACTION_LOG_HEADER_MIN_SIZE) {
                mail_transaction_log_file_set_corrupted(file,

diff --git a/src/lib-index/mail-transaction-log.h b/src/lib-index/mail-transaction-log.h
index 25e0dc2a4a355213de33603c96526eb1b7af7303..32b75908c8477d69144ca29e8bcc97735d8034ab 100644 (file)
--- a/src/lib-index/mail-transaction-log.h
+++ b/src/lib-index/mail-transaction-log.h
@@ -5,7 +5,7 @@ struct mail_index;
 struct mail_index_transaction;
 
 #define MAIL_TRANSACTION_LOG_MAJOR_VERSION 1
-#define MAIL_TRANSACTION_LOG_MINOR_VERSION 1
+#define MAIL_TRANSACTION_LOG_MINOR_VERSION 2
 #define MAIL_TRANSACTION_LOG_HEADER_MIN_SIZE 24
 
 struct mail_transaction_log_header {
@@ -18,7 +18,10 @@ struct mail_transaction_log_header {
        uint32_t prev_file_seq;
        uint32_t prev_file_offset;
        uint32_t create_stamp;
-       uint64_t initial_modseq;
+       uint64_t initial_modseq; /* v1.1+ */
+
+       uint8_t compat_flags; /* enum mail_index_header_compat_flags, v1.2+ */
+       uint8_t unused[3];
 };
 
 enum mail_transaction_type {

diff --git a/src/util/logview.c b/src/util/logview.c
index fb7bcc3480abbdb00ea7868b8273437940553294..b88982ab85a756bacf068e92538df6a195f0c8d4 100644 (file)
--- a/src/util/logview.c
+++ b/src/util/logview.c
@@ -45,6 +45,7 @@ static void dump_hdr(int fd, uint64_t *modseq_r)
        printf("create stamp = %u\n", hdr.create_stamp);
        printf("initial modseq = %llu\n",
               (unsigned long long)hdr.initial_modseq);
+       printf("compat flags = %x\n", hdr.compat_flags);
        *modseq_r = hdr.initial_modseq;
 }