qemu-img check -r for repairing images

The QED block driver already provides the functionality to not only
detect inconsistencies in images, but also fix them. However, this
functionality cannot be manually invoked with qemu-img, but the
check happens only automatically during bdrv_open().

This adds a -r switch to qemu-img check that allows manual invocation
of an image repair.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/block.c b/block.c
index c07ff390ce16f0903cecb17c341d61cdde2a1e17..355ac8618a7880ecf90cc0bee182ef200988d1bf 100644 (file)
--- a/block.c
+++ b/block.c
@@ -1222,14 +1222,14 @@ bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
  * free of errors) or -errno when an internal error occurred. The results of the
  * check are stored in res.
  */
-int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
+int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
 {
     if (bs->drv->bdrv_check == NULL) {
         return -ENOTSUP;
     }
 
     memset(res, 0, sizeof(*res));
-    return bs->drv->bdrv_check(bs, res);
+    return bs->drv->bdrv_check(bs, res, fix);
 }
 
 #define COMMIT_BUF_SECTORS 2048

diff --git a/block.h b/block.h
index 799cf48cc2f72a8eefffa097d8766748707e89f6..61b7e8ecb9448da193dd85d3e525d1340a4ed10e 100644 (file)
--- a/block.h
+++ b/block.h
@@ -190,7 +190,12 @@ typedef struct BdrvCheckResult {
     BlockFragInfo bfi;
 } BdrvCheckResult;
 
-int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res);
+typedef enum {
+    BDRV_FIX_LEAKS    = 1,
+    BDRV_FIX_ERRORS   = 2,
+} BdrvCheckMode;
+
+int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 
 /* async block I/O */
 typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,

diff --git a/block/qcow2.c b/block/qcow2.c
index c2e49cded3611319848c92041ac76d70843cfb63..77970155ab5ced3988fcb59c99226a262ec9f09e 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1470,8 +1470,13 @@ static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 }
 
 
-static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result)
+static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
+                       BdrvCheckMode fix)
 {
+    if (fix) {
+        return -ENOTSUP;
+    }
+
     return qcow2_check_refcounts(bs, result);
 }
 

diff --git a/block/qed.c b/block/qed.c
index 30a31f907f2d03721214971198f7109a88325fcf..ab5972466cc4d7caaf6d801c2cbd185733607039 100644 (file)
--- a/block/qed.c
+++ b/block/qed.c
@@ -1517,11 +1517,12 @@ static void bdrv_qed_invalidate_cache(BlockDriverState *bs)
     bdrv_qed_open(bs, bs->open_flags);
 }
 
-static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result)
+static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result,
+                          BdrvCheckMode fix)
 {
     BDRVQEDState *s = bs->opaque;
 
-    return qed_check(s, result, false);
+    return qed_check(s, result, !!fix);
 }
 
 static QEMUOptionParameter qed_create_options[] = {

diff --git a/block/vdi.c b/block/vdi.c
index 119d3c74da88d566b2e8c6ce5b1d718109c867da..57325d65c4a87e8331f2cfac1d4c776c415e7790 100644 (file)
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -277,7 +277,8 @@ static void vdi_header_print(VdiHeader *header)
 }
 #endif
 
-static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res)
+static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res,
+                     BdrvCheckMode fix)
 {
     /* TODO: additional checks possible. */
     BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
@@ -286,6 +287,10 @@ static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res)
     uint32_t *bmap;
     logout("\n");
 
+    if (fix) {
+        return -ENOTSUP;
+    }
+
     bmap = g_malloc(s->header.blocks_in_image * sizeof(uint32_t));
     memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t));
 

diff --git a/block_int.h b/block_int.h
index 3d4abc6575adbf324ebf48af9e71717bc5c9e65d..1fb5352d0ec4791cfabbef888c91c1607fe011ae 100644 (file)
--- a/block_int.h
+++ b/block_int.h
@@ -241,7 +241,8 @@ struct BlockDriver {
      * Returns 0 for completed check, -errno for internal errors.
      * The check results are stored in result.
      */
-    int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
+    int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
+        BdrvCheckMode fix);
 
     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 

diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 49dce7c928923f6bee3c7b3e21d62a0bfaa69f4e..39419a0314ba07e5ad15988f58eab0447a0e17bd 100644 (file)
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -10,9 +10,9 @@ STEXI
 ETEXI
 
 DEF("check", img_check,
-    "check [-f fmt] filename")
+    "check [-f fmt] [-r [leaks | all]] filename")
 STEXI
-@item check [-f @var{fmt}] @var{filename}
+@item check [-f @var{fmt}] [-r [leaks | all]] @var{filename}
 ETEXI
 
 DEF("create", img_create,

diff --git a/qemu-img.c b/qemu-img.c
index c8a70ffc935daee2cc91a99a562075389aa4c6db..c45ff62a28b9ee1c6c5662c855d4a257c35e92d2 100644 (file)
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -85,6 +85,12 @@ static void help(void)
            "  '-S' indicates the consecutive number of bytes that must contain only zeros\n"
            "       for qemu-img to create a sparse image during conversion\n"
            "\n"
+           "Parameters to check subcommand:\n"
+           "  '-r' tries to repair any inconsistencies that are found during the check.\n"
+           "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
+           "       kinds of errors, with a higher risk of choosing the wrong fix or\n"
+           "       hiding corruption that has already occured.\n"
+           "\n"
            "Parameters to snapshot subcommand:\n"
            "  'snapshot' is the name of the snapshot to create, apply or delete\n"
            "  '-a' applies a snapshot (revert disk to saved state)\n"
@@ -372,10 +378,12 @@ static int img_check(int argc, char **argv)
     const char *filename, *fmt;
     BlockDriverState *bs;
     BdrvCheckResult result;
+    int fix = 0;
+    int flags = BDRV_O_FLAGS;
 
     fmt = NULL;
     for(;;) {
-        c = getopt(argc, argv, "f:h");
+        c = getopt(argc, argv, "f:hr:");
         if (c == -1) {
             break;
         }
@@ -387,6 +395,17 @@ static int img_check(int argc, char **argv)
         case 'f':
             fmt = optarg;
             break;
+        case 'r':
+            flags |= BDRV_O_RDWR;
+
+            if (!strcmp(optarg, "leaks")) {
+                fix = BDRV_FIX_LEAKS;
+            } else if (!strcmp(optarg, "all")) {
+                fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
+            } else {
+                help();
+            }
+            break;
         }
     }
     if (optind >= argc) {
@@ -394,11 +413,11 @@ static int img_check(int argc, char **argv)
     }
     filename = argv[optind++];
 
-    bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS);
+    bs = bdrv_new_open(filename, fmt, flags);
     if (!bs) {
         return 1;
     }
-    ret = bdrv_check(bs, &result);
+    ret = bdrv_check(bs, &result, fix);
 
     if (ret == -ENOTSUP) {
         error_report("This image format does not support checks");

diff --git a/qemu-img.texi b/qemu-img.texi
index 6fc3c28e0d6492bfd61fd03ad9346be48677ac14..5a7b2bb1f26c94601545c96f7d67ba21ef47d280 100644 (file)
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -70,10 +70,15 @@ lists all snapshots in the given image
 Command description:
 
 @table @option
-@item check [-f @var{fmt}] @var{filename}
+@item check [-f @var{fmt}] [-r [leaks | all]] @var{filename}
 
 Perform a consistency check on the disk image @var{filename}.
 
+If @code{-r} is specified, qemu-img tries to repair any inconsistencies found
+during the check. @code{-r leaks} repairs only cluster leaks, whereas
+@code{-r all} fixes all kinds of errors, with a higher risk of choosing the
+wrong fix or hiding corruption that has already occured.
+
 Only the formats @code{qcow2}, @code{qed} and @code{vdi} support
 consistency checks.