[PATCH v7 6/8] parallels: Image repairing in parallels_open()

[Alexander Ivanov]

Repair an image at opening if the image is unclean or out-of-image
corruption was detected.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
 block/parallels.c | 70 +++++++++++++++++++++++++----------------------
 1 file changed, 38 insertions(+), 32 deletions(-)

diff --git a/block/parallels.c b/block/parallels.c
index 0f207c4b32..51fd8ddf5a 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -947,7 +947,7 @@ static int parallels_open(BlockDriverState *bs, QDict 
*options, int flags,
     BDRVParallelsState *s = bs->opaque;
     ParallelsHeader ph;
     int ret, size, i;
-    int64_t file_nb_sectors;
+    int64_t file_nb_sectors, sector;
     QemuOpts *opts = NULL;
     Error *local_err = NULL;
     char *buf;
@@ -1018,11 +1018,6 @@ static int parallels_open(BlockDriverState *bs, QDict 
*options, int flags,
            and actual data. We can't avoid read-modify-write... */
         s->header_size = size;
     }
-    if (s->data_end > file_nb_sectors) {
-        error_setg(errp, "Invalid image: incorrect data_off field");
-        ret = -EINVAL;
-        goto fail;
-    }
 
     ret = bdrv_pread(bs->file, 0, s->header_size, s->header, 0);
     if (ret < 0) {
@@ -1030,33 +1025,8 @@ static int parallels_open(BlockDriverState *bs, QDict 
*options, int flags,
     }
     s->bat_bitmap = (uint32_t *)(s->header + 1);
 
-    for (i = 0; i < s->bat_size; i++) {
-        int64_t off = bat2sect(s, i);
-        if (off >= file_nb_sectors) {
-            if (flags & BDRV_O_CHECK) {
-                continue;
-            }
-            error_setg(errp, "parallels: Offset %" PRIi64 " in BAT[%d] entry "
-                       "is larger than file size (%" PRIi64 ")",
-                       off << BDRV_SECTOR_BITS, i,
-                       file_nb_sectors << BDRV_SECTOR_BITS);
-            ret = -EINVAL;
-            goto fail;
-        }
-        if (off >= s->data_end) {
-            s->data_end = off + s->tracks;
-        }
-    }
-
     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
-        /* Image was not closed correctly. The check is mandatory */
         s->header_unclean = true;
-        if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
-            error_setg(errp, "parallels: Image was not closed correctly; "
-                       "cannot be opened read/write");
-            ret = -EACCES;
-            goto fail;
-        }
     }
 
     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, errp);
@@ -1117,10 +1087,40 @@ static int parallels_open(BlockDriverState *bs, QDict 
*options, int flags,
                bdrv_get_device_or_node_name(bs));
     ret = migrate_add_blocker(s->migration_blocker, errp);
     if (ret < 0) {
-        error_free(s->migration_blocker);
+        error_setg(errp, "Migration blocker error");
         goto fail;
     }
     qemu_co_mutex_init(&s->lock);
+
+    for (i = 0; i < s->bat_size; i++) {
+        sector = bat2sect(s, i);
+        if (sector + s->tracks > s->data_end) {
+            s->data_end = sector + s->tracks;
+        }
+    }
+
+    /*
+     * We don't repair the image here if it's opened for checks. Also we don't
+     * want to change inactive images and can't change readonly images.
+     */
+    if ((flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) || !(flags & BDRV_O_RDWR)) {
+        return 0;
+    }
+
+    /*
+     * Repair the image if it's dirty or
+     * out-of-image corruption was detected.
+     */
+    if (s->data_end > file_nb_sectors || s->header_unclean) {
+        BdrvCheckResult res;
+        ret = bdrv_check(bs, &res, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
+        if (ret < 0) {
+            error_setg_errno(errp, -ret, "Could not repair corrupted image");
+            migrate_del_blocker(s->migration_blocker);
+            goto fail;
+        }
+    }
+
     return 0;
 
 fail_format:
@@ -1128,6 +1128,12 @@ fail_format:
 fail_options:
     ret = -EINVAL;
 fail:
+    /*
+     * "s" object was allocated by g_malloc0 so we can safely
+     * try to free its fields even they were not allocated.
+     */
+    error_free(s->migration_blocker);
+    g_free(s->bat_dirty_bmap);
     qemu_vfree(s->header);
     return ret;
 }
-- 
2.34.1