X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/072035eba1ceb87a987cc03d756fc2da3f3ba058..79d465839f6be12d614ee2bdf3514c5d645116ff:/qemu-io-cmds.c

diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index e34f777118..a6a70fc3dc 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -1,7 +1,7 @@
 /*
  * Command line utility to exercise the QEMU I/O path.
  *
- * Copyright (C) 2009 Red Hat, Inc.
+ * Copyright (C) 2009-2016 Red Hat, Inc.
  * Copyright (c) 2003-2005 Silicon Graphics, Inc.
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
@@ -18,7 +18,6 @@
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/timer.h"
-#include "sysemu/block-backend.h"
 #include "qemu/cutils.h"
 
 #define CMD_NOFILE_OK   0x01
@@ -36,6 +35,13 @@ static int compare_cmdname(const void *a, const void *b)
 
 void qemuio_add_command(const cmdinfo_t *ci)
 {
+    /* ci->perm assumes a file is open, but the GLOBAL and NOFILE_OK
+     * flags allow it not to be, so that combination is invalid.
+     * Catch it now rather than letting it manifest as a crash if a
+     * particular set of command line options are used.
+     */
+    assert(ci->perm == 0 ||
+           (ci->flags & (CMD_FLAG_GLOBAL | CMD_NOFILE_OK)) == 0);
     cmdtab = g_renew(cmdinfo_t, cmdtab, ++ncmds);
     cmdtab[ncmds - 1] = *ci;
     qsort(cmdtab, ncmds, sizeof(*cmdtab), compare_cmdname);
@@ -84,6 +90,29 @@ static int command(BlockBackend *blk, const cmdinfo_t *ct, int argc,
         }
         return 0;
     }
+
+    /* Request additional permissions if necessary for this command. The caller
+     * is responsible for restoring the original permissions afterwards if this
+     * is what it wants. */
+    if (ct->perm && blk_is_available(blk)) {
+        uint64_t orig_perm, orig_shared_perm;
+        blk_get_perm(blk, &orig_perm, &orig_shared_perm);
+
+        if (ct->perm & ~orig_perm) {
+            uint64_t new_perm;
+            Error *local_err = NULL;
+            int ret;
+
+            new_perm = orig_perm | ct->perm;
+
+            ret = blk_set_perm(blk, new_perm, orig_shared_perm, &local_err);
+            if (ret < 0) {
+                error_report_err(local_err);
+                return 0;
+            }
+        }
+    }
+
     optind = 0;
     return ct->cfunc(blk, argc, argv);
 }
@@ -138,15 +167,17 @@ static char **breakline(char *input, int *count)
 
 static int64_t cvtnum(const char *s)
 {
-    char *end;
-    int64_t ret;
+    int err;
+    uint64_t value;
 
-    ret = qemu_strtosz_suffix(s, &end, QEMU_STRTOSZ_DEFSUFFIX_B);
-    if (*end != '\0') {
-        /* Detritus at the end of the string */
-        return -EINVAL;
+    err = qemu_strtosz(s, NULL, &value);
+    if (err < 0) {
+        return err;
     }
-    return ret;
+    if (value > INT64_MAX) {
+        return -ERANGE;
+    }
+    return value;
 }
 
 static void print_cvtnum_err(int64_t rc, const char *arg)
@@ -345,7 +376,7 @@ static void dump_buffer(const void *buffer, int64_t offset, int64_t len)
 }
 
 static void print_report(const char *op, struct timeval *t, int64_t offset,
-                         int64_t count, int64_t total, int cnt, int Cflag)
+                         int64_t count, int64_t total, int cnt, bool Cflag)
 {
     char s1[64], s2[64], ts[64];
 
@@ -389,15 +420,15 @@ create_iovec(BlockBackend *blk, QEMUIOVector *qiov, char **argv, int nr_iov,
             goto fail;
         }
 
-        /* should be SIZE_T_MAX, but that doesn't exist */
-        if (len > INT_MAX) {
-            printf("Argument '%s' exceeds maximum size %d\n", arg, INT_MAX);
+        if (len > BDRV_REQUEST_MAX_BYTES) {
+            printf("Argument '%s' exceeds maximum size %" PRIu64 "\n", arg,
+                   (uint64_t)BDRV_REQUEST_MAX_BYTES);
             goto fail;
         }
 
-        if (len & 0x1ff) {
-            printf("length argument %" PRId64
-                   " is not sector aligned\n", len);
+        if (count > BDRV_REQUEST_MAX_BYTES - len) {
+            printf("The total number of bytes exceed the maximum size %" PRIu64
+                   "\n", (uint64_t)BDRV_REQUEST_MAX_BYTES);
             goto fail;
         }
 
@@ -419,48 +450,14 @@ fail:
     return buf;
 }
 
-static int do_read(BlockBackend *blk, char *buf, int64_t offset, int64_t count,
-                   int64_t *total)
-{
-    int ret;
-
-    if (count >> 9 > INT_MAX) {
-        return -ERANGE;
-    }
-
-    ret = blk_read(blk, offset >> 9, (uint8_t *)buf, count >> 9);
-    if (ret < 0) {
-        return ret;
-    }
-    *total = count;
-    return 1;
-}
-
-static int do_write(BlockBackend *blk, char *buf, int64_t offset, int64_t count,
-                    int64_t *total)
-{
-    int ret;
-
-    if (count >> 9 > INT_MAX) {
-        return -ERANGE;
-    }
-
-    ret = blk_write(blk, offset >> 9, (uint8_t *)buf, count >> 9);
-    if (ret < 0) {
-        return ret;
-    }
-    *total = count;
-    return 1;
-}
-
 static int do_pread(BlockBackend *blk, char *buf, int64_t offset,
-                    int64_t count, int64_t *total)
+                    int64_t bytes, int64_t *total)
 {
-    if (count > INT_MAX) {
+    if (bytes > INT_MAX) {
         return -ERANGE;
     }
 
-    *total = blk_pread(blk, offset, (uint8_t *)buf, count);
+    *total = blk_pread(blk, offset, (uint8_t *)buf, bytes);
     if (*total < 0) {
         return *total;
     }
@@ -468,13 +465,13 @@ static int do_pread(BlockBackend *blk, char *buf, int64_t offset,
 }
 
 static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset,
-                     int64_t count, int64_t *total)
+                     int64_t bytes, int flags, int64_t *total)
 {
-    if (count > INT_MAX) {
+    if (bytes > INT_MAX) {
         return -ERANGE;
     }
 
-    *total = blk_pwrite(blk, offset, (uint8_t *)buf, count);
+    *total = blk_pwrite(blk, offset, (uint8_t *)buf, bytes, flags);
     if (*total < 0) {
         return *total;
     }
@@ -484,45 +481,47 @@ static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset,
 typedef struct {
     BlockBackend *blk;
     int64_t offset;
-    int64_t count;
+    int64_t bytes;
     int64_t *total;
+    int flags;
     int ret;
     bool done;
 } CoWriteZeroes;
 
-static void coroutine_fn co_write_zeroes_entry(void *opaque)
+static void coroutine_fn co_pwrite_zeroes_entry(void *opaque)
 {
     CoWriteZeroes *data = opaque;
 
-    data->ret = blk_co_write_zeroes(data->blk, data->offset / BDRV_SECTOR_SIZE,
-                                    data->count / BDRV_SECTOR_SIZE, 0);
+    data->ret = blk_co_pwrite_zeroes(data->blk, data->offset, data->bytes,
+                                     data->flags);
     data->done = true;
     if (data->ret < 0) {
         *data->total = data->ret;
         return;
     }
 
-    *data->total = data->count;
+    *data->total = data->bytes;
 }
 
-static int do_co_write_zeroes(BlockBackend *blk, int64_t offset, int64_t count,
-                              int64_t *total)
+static int do_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
+                               int64_t bytes, int flags, int64_t *total)
 {
     Coroutine *co;
     CoWriteZeroes data = {
         .blk    = blk,
         .offset = offset,
-        .count  = count,
+        .bytes  = bytes,
         .total  = total,
+        .flags  = flags,
         .done   = false,
     };
 
-    if (count >> BDRV_SECTOR_BITS > INT_MAX) {
+    if (bytes > INT_MAX) {
         return -ERANGE;
     }
 
-    co = qemu_coroutine_create(co_write_zeroes_entry);
-    qemu_coroutine_enter(co, &data);
+    co = qemu_coroutine_create(co_pwrite_zeroes_entry, &data);
+    bdrv_coroutine_enter(blk_bs(blk), co);
     while (!data.done) {
         aio_poll(blk_get_aio_context(blk), true);
     }
@@ -534,19 +533,19 @@ static int do_co_write_zeroes(BlockBackend *blk, int64_t offset, int64_t count,
 }
 
 static int do_write_compressed(BlockBackend *blk, char *buf, int64_t offset,
-                               int64_t count, int64_t *total)
+                               int64_t bytes, int64_t *total)
 {
     int ret;
 
-    if (count >> 9 > INT_MAX) {
+    if (bytes >> 9 > BDRV_REQUEST_MAX_SECTORS) {
         return -ERANGE;
     }
 
-    ret = blk_write_compressed(blk, offset >> 9, (uint8_t *)buf, count >> 9);
+    ret = blk_pwrite_compressed(blk, offset, buf, bytes);
     if (ret < 0) {
         return ret;
     }
-    *total = count;
+    *total = bytes;
     return 1;
 }
 
@@ -589,8 +588,7 @@ static int do_aio_readv(BlockBackend *blk, QEMUIOVector *qiov,
 {
     int async_ret = NOT_DONE;
 
-    blk_aio_readv(blk, offset >> 9, qiov, qiov->size >> 9,
-                  aio_rw_done, &async_ret);
+    blk_aio_preadv(blk, offset, qiov, 0, aio_rw_done, &async_ret);
     while (async_ret == NOT_DONE) {
         main_loop_wait(false);
     }
@@ -600,12 +598,11 @@ static int do_aio_readv(BlockBackend *blk, QEMUIOVector *qiov,
 }
 
 static int do_aio_writev(BlockBackend *blk, QEMUIOVector *qiov,
-                         int64_t offset, int *total)
+                         int64_t offset, int flags, int *total)
 {
     int async_ret = NOT_DONE;
 
-    blk_aio_writev(blk, offset >> 9, qiov, qiov->size >> 9,
-                   aio_rw_done, &async_ret);
+    blk_aio_pwritev(blk, offset, qiov, flags, aio_rw_done, &async_ret);
     while (async_ret == NOT_DONE) {
         main_loop_wait(false);
     }
@@ -614,49 +611,6 @@ static int do_aio_writev(BlockBackend *blk, QEMUIOVector *qiov,
     return async_ret < 0 ? async_ret : 1;
 }
 
-struct multiwrite_async_ret {
-    int num_done;
-    int error;
-};
-
-static void multiwrite_cb(void *opaque, int ret)
-{
-    struct multiwrite_async_ret *async_ret = opaque;
-
-    async_ret->num_done++;
-    if (ret < 0) {
-        async_ret->error = ret;
-    }
-}
-
-static int do_aio_multiwrite(BlockBackend *blk, BlockRequest* reqs,
-                             int num_reqs, int *total)
-{
-    int i, ret;
-    struct multiwrite_async_ret async_ret = {
-        .num_done = 0,
-        .error = 0,
-    };
-
-    *total = 0;
-    for (i = 0; i < num_reqs; i++) {
-        reqs[i].cb = multiwrite_cb;
-        reqs[i].opaque = &async_ret;
-        *total += reqs[i].qiov->size;
-    }
-
-    ret = blk_aio_multiwrite(blk, reqs, num_reqs);
-    if (ret < 0) {
-        return ret;
-    }
-
-    while (async_ret.num_done < num_reqs) {
-        main_loop_wait(false);
-    }
-
-    return async_ret.error < 0 ? async_ret.error : 1;
-}
-
 static void read_help(void)
 {
     printf(
@@ -671,7 +625,7 @@ static void read_help(void)
 " -b, -- read from the VM state rather than the virtual disk\n"
 " -C, -- report statistics in a machine parsable format\n"
 " -l, -- length for pattern verification (only with -P)\n"
-" -p, -- use blk_pread to read the file\n"
+" -p, -- ignored for backwards compatibility\n"
 " -P, -- use a pattern to verify read data\n"
 " -q, -- quiet mode, do not show I/O statistics\n"
 " -s, -- start offset for pattern verification (only with -P)\n"
@@ -687,7 +641,7 @@ static const cmdinfo_t read_cmd = {
     .cfunc      = read_f,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-abCpqv] [-P pattern [-s off] [-l len]] off len",
+    .args       = "[-abCqv] [-P pattern [-s off] [-l len]] off len",
     .oneline    = "reads a number of bytes at a specified offset",
     .help       = read_help,
 };
@@ -695,8 +649,8 @@ static const cmdinfo_t read_cmd = {
 static int read_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timeval t1, t2;
-    int Cflag = 0, pflag = 0, qflag = 0, vflag = 0;
-    int Pflag = 0, sflag = 0, lflag = 0, bflag = 0;
+    bool Cflag = false, qflag = false, vflag = false;
+    bool Pflag = false, sflag = false, lflag = false, bflag = false;
     int c, cnt;
     char *buf;
     int64_t offset;
@@ -709,13 +663,13 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
     while ((c = getopt(argc, argv, "bCl:pP:qs:v")) != -1) {
         switch (c) {
         case 'b':
-            bflag = 1;
+            bflag = true;
             break;
         case 'C':
-            Cflag = 1;
+            Cflag = true;
             break;
         case 'l':
-            lflag = 1;
+            lflag = true;
             pattern_count = cvtnum(optarg);
             if (pattern_count < 0) {
                 print_cvtnum_err(pattern_count, optarg);
@@ -723,20 +677,20 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
             }
             break;
         case 'p':
-            pflag = 1;
+            /* Ignored for backwards compatibility */
             break;
         case 'P':
-            Pflag = 1;
+            Pflag = true;
             pattern = parse_pattern(optarg);
             if (pattern < 0) {
                 return 0;
             }
             break;
         case 'q':
-            qflag = 1;
+            qflag = true;
             break;
         case 's':
-            sflag = 1;
+            sflag = true;
             pattern_offset = cvtnum(optarg);
             if (pattern_offset < 0) {
                 print_cvtnum_err(pattern_offset, optarg);
@@ -744,7 +698,7 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
             }
             break;
         case 'v':
-            vflag = 1;
+            vflag = true;
             break;
         default:
             return qemuio_command_usage(&read_cmd);
@@ -755,11 +709,6 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
         return qemuio_command_usage(&read_cmd);
     }
 
-    if (bflag && pflag) {
-        printf("-b and -p cannot be specified at the same time\n");
-        return 0;
-    }
-
     offset = cvtnum(argv[optind]);
     if (offset < 0) {
         print_cvtnum_err(offset, argv[optind]);
@@ -771,9 +720,9 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
     if (count < 0) {
         print_cvtnum_err(count, argv[optind]);
         return 0;
-    } else if (count > SIZE_MAX) {
+    } else if (count > BDRV_REQUEST_MAX_BYTES) {
         printf("length cannot exceed %" PRIu64 ", given %s\n",
-               (uint64_t) SIZE_MAX, argv[optind]);
+               (uint64_t)BDRV_REQUEST_MAX_BYTES, argv[optind]);
         return 0;
     }
 
@@ -790,14 +739,14 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
         return 0;
     }
 
-    if (!pflag) {
-        if (offset & 0x1ff) {
-            printf("offset %" PRId64 " is not sector aligned\n",
+    if (bflag) {
+        if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) {
+            printf("%" PRId64 " is not a sector-aligned value for 'offset'\n",
                    offset);
             return 0;
         }
-        if (count & 0x1ff) {
-            printf("count %"PRId64" is not sector aligned\n",
+        if (!QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)) {
+            printf("%"PRId64" is not a sector-aligned value for 'count'\n",
                    count);
             return 0;
         }
@@ -806,12 +755,10 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
     buf = qemu_io_alloc(blk, count, 0xab);
 
     gettimeofday(&t1, NULL);
-    if (pflag) {
-        cnt = do_pread(blk, buf, offset, count, &total);
-    } else if (bflag) {
+    if (bflag) {
         cnt = do_load_vmstate(blk, buf, offset, count, &total);
     } else {
-        cnt = do_read(blk, buf, offset, count, &total);
+        cnt = do_pread(blk, buf, offset, count, &total);
     }
     gettimeofday(&t2, NULL);
 
@@ -875,7 +822,7 @@ static const cmdinfo_t readv_cmd = {
     .cfunc      = readv_f,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-Cqv] [-P pattern ] off len [len..]",
+    .args       = "[-Cqv] [-P pattern] off len [len..]",
     .oneline    = "reads a number of bytes at a specified offset",
     .help       = readv_help,
 };
@@ -883,7 +830,7 @@ static const cmdinfo_t readv_cmd = {
 static int readv_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timeval t1, t2;
-    int Cflag = 0, qflag = 0, vflag = 0;
+    bool Cflag = false, qflag = false, vflag = false;
     int c, cnt;
     char *buf;
     int64_t offset;
@@ -892,25 +839,25 @@ static int readv_f(BlockBackend *blk, int argc, char **argv)
     int nr_iov;
     QEMUIOVector qiov;
     int pattern = 0;
-    int Pflag = 0;
+    bool Pflag = false;
 
     while ((c = getopt(argc, argv, "CP:qv")) != -1) {
         switch (c) {
         case 'C':
-            Cflag = 1;
+            Cflag = true;
             break;
         case 'P':
-            Pflag = 1;
+            Pflag = true;
             pattern = parse_pattern(optarg);
             if (pattern < 0) {
                 return 0;
             }
             break;
         case 'q':
-            qflag = 1;
+            qflag = true;
             break;
         case 'v':
-            vflag = 1;
+            vflag = true;
             break;
         default:
             return qemuio_command_usage(&readv_cmd);
@@ -929,12 +876,6 @@ static int readv_f(BlockBackend *blk, int argc, char **argv)
     }
     optind++;
 
-    if (offset & 0x1ff) {
-        printf("offset %" PRId64 " is not sector aligned\n",
-               offset);
-        return 0;
-    }
-
     nr_iov = argc - optind;
     buf = create_iovec(blk, &qiov, &argv[optind], nr_iov, 0xab);
     if (buf == NULL) {
@@ -991,11 +932,13 @@ static void write_help(void)
 " filled with a set pattern (0xcdcdcdcd).\n"
 " -b, -- write to the VM state rather than the virtual disk\n"
 " -c, -- write compressed data with blk_write_compressed\n"
-" -p, -- use blk_pwrite to write the file\n"
+" -f, -- use Force Unit Access semantics\n"
+" -p, -- ignored for backwards compatibility\n"
 " -P, -- use different pattern to fill file\n"
 " -C, -- report statistics in a machine parsable format\n"
 " -q, -- quiet mode, do not show I/O statistics\n"
-" -z, -- write zeroes using blk_co_write_zeroes\n"
+" -u, -- with -z, allow unmapping\n"
+" -z, -- write zeroes using blk_co_pwrite_zeroes\n"
 "\n");
 }
 
@@ -1005,9 +948,10 @@ static const cmdinfo_t write_cmd = {
     .name       = "write",
     .altname    = "w",
     .cfunc      = write_f,
+    .perm       = BLK_PERM_WRITE,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-bcCpqz] [-P pattern ] off len",
+    .args       = "[-bcCfquz] [-P pattern] off len",
     .oneline    = "writes a number of bytes at a specified offset",
     .help       = write_help,
 };
@@ -1015,8 +959,9 @@ static const cmdinfo_t write_cmd = {
 static int write_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timeval t1, t2;
-    int Cflag = 0, pflag = 0, qflag = 0, bflag = 0, Pflag = 0, zflag = 0;
-    int cflag = 0;
+    bool Cflag = false, qflag = false, bflag = false;
+    bool Pflag = false, zflag = false, cflag = false;
+    int flags = 0;
     int c, cnt;
     char *buf = NULL;
     int64_t offset;
@@ -1025,32 +970,38 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
     int64_t total = 0;
     int pattern = 0xcd;
 
-    while ((c = getopt(argc, argv, "bcCpP:qz")) != -1) {
+    while ((c = getopt(argc, argv, "bcCfpP:quz")) != -1) {
         switch (c) {
         case 'b':
-            bflag = 1;
+            bflag = true;
             break;
         case 'c':
-            cflag = 1;
+            cflag = true;
             break;
         case 'C':
-            Cflag = 1;
+            Cflag = true;
+            break;
+        case 'f':
+            flags |= BDRV_REQ_FUA;
             break;
         case 'p':
-            pflag = 1;
+            /* Ignored for backwards compatibility */
             break;
         case 'P':
-            Pflag = 1;
+            Pflag = true;
             pattern = parse_pattern(optarg);
             if (pattern < 0) {
                 return 0;
             }
             break;
         case 'q':
-            qflag = 1;
+            qflag = true;
+            break;
+        case 'u':
+            flags |= BDRV_REQ_MAY_UNMAP;
             break;
         case 'z':
-            zflag = 1;
+            zflag = true;
             break;
         default:
             return qemuio_command_usage(&write_cmd);
@@ -1061,8 +1012,18 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
         return qemuio_command_usage(&write_cmd);
     }
 
-    if (bflag + pflag + zflag > 1) {
-        printf("-b, -p, or -z cannot be specified at the same time\n");
+    if (bflag && zflag) {
+        printf("-b and -z cannot be specified at the same time\n");
+        return 0;
+    }
+
+    if ((flags & BDRV_REQ_FUA) && (bflag || cflag)) {
+        printf("-f and -b or -c cannot be specified at the same time\n");
+        return 0;
+    }
+
+    if ((flags & BDRV_REQ_MAY_UNMAP) && !zflag) {
+        printf("-u requires -z to be specified\n");
         return 0;
     }
 
@@ -1082,21 +1043,21 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
     if (count < 0) {
         print_cvtnum_err(count, argv[optind]);
         return 0;
-    } else if (count > SIZE_MAX) {
+    } else if (count > BDRV_REQUEST_MAX_BYTES) {
         printf("length cannot exceed %" PRIu64 ", given %s\n",
-               (uint64_t) SIZE_MAX, argv[optind]);
+               (uint64_t)BDRV_REQUEST_MAX_BYTES, argv[optind]);
         return 0;
     }
 
-    if (!pflag) {
-        if (offset & 0x1ff) {
-            printf("offset %" PRId64 " is not sector aligned\n",
+    if (bflag || cflag) {
+        if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) {
+            printf("%" PRId64 " is not a sector-aligned value for 'offset'\n",
                    offset);
             return 0;
         }
 
-        if (count & 0x1ff) {
-            printf("count %"PRId64" is not sector aligned\n",
+        if (!QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)) {
+            printf("%"PRId64" is not a sector-aligned value for 'count'\n",
                    count);
             return 0;
         }
@@ -1107,16 +1068,14 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
     }
 
     gettimeofday(&t1, NULL);
-    if (pflag) {
-        cnt = do_pwrite(blk, buf, offset, count, &total);
-    } else if (bflag) {
+    if (bflag) {
         cnt = do_save_vmstate(blk, buf, offset, count, &total);
     } else if (zflag) {
-        cnt = do_co_write_zeroes(blk, offset, count, &total);
+        cnt = do_co_pwrite_zeroes(blk, offset, count, flags, &total);
     } else if (cflag) {
         cnt = do_write_compressed(blk, buf, offset, count, &total);
     } else {
-        cnt = do_write(blk, buf, offset, count, &total);
+        cnt = do_pwrite(blk, buf, offset, count, flags, &total);
     }
     gettimeofday(&t2, NULL);
 
@@ -1155,6 +1114,7 @@ writev_help(void)
 " filled with a set pattern (0xcdcdcdcd).\n"
 " -P, -- use different pattern to fill file\n"
 " -C, -- report statistics in a machine parsable format\n"
+" -f, -- use Force Unit Access semantics\n"
 " -q, -- quiet mode, do not show I/O statistics\n"
 "\n");
 }
@@ -1164,9 +1124,10 @@ static int writev_f(BlockBackend *blk, int argc, char **argv);
 static const cmdinfo_t writev_cmd = {
     .name       = "writev",
     .cfunc      = writev_f,
+    .perm       = BLK_PERM_WRITE,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-Cq] [-P pattern ] off len [len..]",
+    .args       = "[-Cfq] [-P pattern] off len [len..]",
     .oneline    = "writes a number of bytes at a specified offset",
     .help       = writev_help,
 };
@@ -1174,7 +1135,8 @@ static const cmdinfo_t writev_cmd = {
 static int writev_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timeval t1, t2;
-    int Cflag = 0, qflag = 0;
+    bool Cflag = false, qflag = false;
+    int flags = 0;
     int c, cnt;
     char *buf;
     int64_t offset;
@@ -1184,13 +1146,16 @@ static int writev_f(BlockBackend *blk, int argc, char **argv)
     int pattern = 0xcd;
     QEMUIOVector qiov;
 
-    while ((c = getopt(argc, argv, "CqP:")) != -1) {
+    while ((c = getopt(argc, argv, "CfqP:")) != -1) {
         switch (c) {
         case 'C':
-            Cflag = 1;
+            Cflag = true;
+            break;
+        case 'f':
+            flags |= BDRV_REQ_FUA;
             break;
         case 'q':
-            qflag = 1;
+            qflag = true;
             break;
         case 'P':
             pattern = parse_pattern(optarg);
@@ -1214,12 +1179,6 @@ static int writev_f(BlockBackend *blk, int argc, char **argv)
     }
     optind++;
 
-    if (offset & 0x1ff) {
-        printf("offset %" PRId64 " is not sector aligned\n",
-               offset);
-        return 0;
-    }
-
     nr_iov = argc - optind;
     buf = create_iovec(blk, &qiov, &argv[optind], nr_iov, pattern);
     if (buf == NULL) {
@@ -1227,7 +1186,7 @@ static int writev_f(BlockBackend *blk, int argc, char **argv)
     }
 
     gettimeofday(&t1, NULL);
-    cnt = do_aio_writev(blk, &qiov, offset, &total);
+    cnt = do_aio_writev(blk, &qiov, offset, flags, &total);
     gettimeofday(&t2, NULL);
 
     if (cnt < 0) {
@@ -1248,175 +1207,16 @@ out:
     return 0;
 }
 
-static void multiwrite_help(void)
-{
-    printf(
-"\n"
-" writes a range of bytes from the given offset source from multiple buffers,\n"
-" in a batch of requests that may be merged by qemu\n"
-"\n"
-" Example:\n"
-" 'multiwrite 512 1k 1k ; 4k 1k'\n"
-"  writes 2 kB at 512 bytes and 1 kB at 4 kB into the open file\n"
-"\n"
-" Writes into a segment of the currently open file, using a buffer\n"
-" filled with a set pattern (0xcdcdcdcd). The pattern byte is increased\n"
-" by one for each request contained in the multiwrite command.\n"
-" -P, -- use different pattern to fill file\n"
-" -C, -- report statistics in a machine parsable format\n"
-" -q, -- quiet mode, do not show I/O statistics\n"
-"\n");
-}
-
-static int multiwrite_f(BlockBackend *blk, int argc, char **argv);
-
-static const cmdinfo_t multiwrite_cmd = {
-    .name       = "multiwrite",
-    .cfunc      = multiwrite_f,
-    .argmin     = 2,
-    .argmax     = -1,
-    .args       = "[-Cq] [-P pattern ] off len [len..] [; off len [len..]..]",
-    .oneline    = "issues multiple write requests at once",
-    .help       = multiwrite_help,
-};
-
-static int multiwrite_f(BlockBackend *blk, int argc, char **argv)
-{
-    struct timeval t1, t2;
-    int Cflag = 0, qflag = 0;
-    int c, cnt;
-    char **buf;
-    int64_t offset, first_offset = 0;
-    /* Some compilers get confused and warn if this is not initialized.  */
-    int total = 0;
-    int nr_iov;
-    int nr_reqs;
-    int pattern = 0xcd;
-    QEMUIOVector *qiovs;
-    int i;
-    BlockRequest *reqs;
-
-    while ((c = getopt(argc, argv, "CqP:")) != -1) {
-        switch (c) {
-        case 'C':
-            Cflag = 1;
-            break;
-        case 'q':
-            qflag = 1;
-            break;
-        case 'P':
-            pattern = parse_pattern(optarg);
-            if (pattern < 0) {
-                return 0;
-            }
-            break;
-        default:
-            return qemuio_command_usage(&writev_cmd);
-        }
-    }
-
-    if (optind > argc - 2) {
-        return qemuio_command_usage(&writev_cmd);
-    }
-
-    nr_reqs = 1;
-    for (i = optind; i < argc; i++) {
-        if (!strcmp(argv[i], ";")) {
-            nr_reqs++;
-        }
-    }
-
-    reqs = g_new0(BlockRequest, nr_reqs);
-    buf = g_new0(char *, nr_reqs);
-    qiovs = g_new(QEMUIOVector, nr_reqs);
-
-    for (i = 0; i < nr_reqs && optind < argc; i++) {
-        int j;
-
-        /* Read the offset of the request */
-        offset = cvtnum(argv[optind]);
-        if (offset < 0) {
-            print_cvtnum_err(offset, argv[optind]);
-            goto out;
-        }
-        optind++;
-
-        if (offset & 0x1ff) {
-            printf("offset %lld is not sector aligned\n",
-                   (long long)offset);
-            goto out;
-        }
-
-        if (i == 0) {
-            first_offset = offset;
-        }
-
-        /* Read lengths for qiov entries */
-        for (j = optind; j < argc; j++) {
-            if (!strcmp(argv[j], ";")) {
-                break;
-            }
-        }
-
-        nr_iov = j - optind;
-
-        /* Build request */
-        buf[i] = create_iovec(blk, &qiovs[i], &argv[optind], nr_iov, pattern);
-        if (buf[i] == NULL) {
-            goto out;
-        }
-
-        reqs[i].qiov = &qiovs[i];
-        reqs[i].sector = offset >> 9;
-        reqs[i].nb_sectors = reqs[i].qiov->size >> 9;
-
-        optind = j + 1;
-
-        pattern++;
-    }
-
-    /* If there were empty requests at the end, ignore them */
-    nr_reqs = i;
-
-    gettimeofday(&t1, NULL);
-    cnt = do_aio_multiwrite(blk, reqs, nr_reqs, &total);
-    gettimeofday(&t2, NULL);
-
-    if (cnt < 0) {
-        printf("aio_multiwrite failed: %s\n", strerror(-cnt));
-        goto out;
-    }
-
-    if (qflag) {
-        goto out;
-    }
-
-    /* Finally, report back -- -C gives a parsable format */
-    t2 = tsub(t2, t1);
-    print_report("wrote", &t2, first_offset, total, total, cnt, Cflag);
-out:
-    for (i = 0; i < nr_reqs; i++) {
-        qemu_io_free(buf[i]);
-        if (reqs[i].qiov != NULL) {
-            qemu_iovec_destroy(&qiovs[i]);
-        }
-    }
-    g_free(buf);
-    g_free(reqs);
-    g_free(qiovs);
-    return 0;
-}
-
 struct aio_ctx {
     BlockBackend *blk;
     QEMUIOVector qiov;
     int64_t offset;
     char *buf;
-    int qflag;
-    int vflag;
-    int Cflag;
-    int Pflag;
-    int zflag;
+    bool qflag;
+    bool vflag;
+    bool Cflag;
+    bool Pflag;
+    bool zflag;
     BlockAcctCookie acct;
     int pattern;
     struct timeval t1;
@@ -1513,6 +1313,7 @@ static void aio_read_help(void)
 " used to ensure all outstanding aio requests have been completed.\n"
 " -C, -- report statistics in a machine parsable format\n"
 " -P, -- use a pattern to verify read data\n"
+" -i, -- treat request as invalid, for exercising stats\n"
 " -v, -- dump buffer to standard output\n"
 " -q, -- quiet mode, do not show I/O statistics\n"
 "\n");
@@ -1525,7 +1326,7 @@ static const cmdinfo_t aio_read_cmd = {
     .cfunc      = aio_read_f,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-Cqv] [-P pattern ] off len [len..]",
+    .args       = "[-Ciqv] [-P pattern] off len [len..]",
     .oneline    = "asynchronously reads a number of bytes",
     .help       = aio_read_help,
 };
@@ -1536,24 +1337,29 @@ static int aio_read_f(BlockBackend *blk, int argc, char **argv)
     struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
 
     ctx->blk = blk;
-    while ((c = getopt(argc, argv, "CP:qv")) != -1) {
+    while ((c = getopt(argc, argv, "CP:iqv")) != -1) {
         switch (c) {
         case 'C':
-            ctx->Cflag = 1;
+            ctx->Cflag = true;
             break;
         case 'P':
-            ctx->Pflag = 1;
+            ctx->Pflag = true;
             ctx->pattern = parse_pattern(optarg);
             if (ctx->pattern < 0) {
                 g_free(ctx);
                 return 0;
             }
             break;
+        case 'i':
+            printf("injecting invalid read request\n");
+            block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_READ);
+            g_free(ctx);
+            return 0;
         case 'q':
-            ctx->qflag = 1;
+            ctx->qflag = true;
             break;
         case 'v':
-            ctx->vflag = 1;
+            ctx->vflag = true;
             break;
         default:
             g_free(ctx);
@@ -1574,14 +1380,6 @@ static int aio_read_f(BlockBackend *blk, int argc, char **argv)
     }
     optind++;
 
-    if (ctx->offset & 0x1ff) {
-        printf("offset %" PRId64 " is not sector aligned\n",
-               ctx->offset);
-        block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_READ);
-        g_free(ctx);
-        return 0;
-    }
-
     nr_iov = argc - optind;
     ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov, 0xab);
     if (ctx->buf == NULL) {
@@ -1593,8 +1391,7 @@ static int aio_read_f(BlockBackend *blk, int argc, char **argv)
     gettimeofday(&ctx->t1, NULL);
     block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,
                      BLOCK_ACCT_READ);
-    blk_aio_readv(blk, ctx->offset >> 9, &ctx->qiov,
-                  ctx->qiov.size >> 9, aio_read_done, ctx);
+    blk_aio_preadv(blk, ctx->offset, &ctx->qiov, 0, aio_read_done, ctx);
     return 0;
 }
 
@@ -1614,8 +1411,11 @@ static void aio_write_help(void)
 " used to ensure all outstanding aio requests have been completed.\n"
 " -P, -- use different pattern to fill file\n"
 " -C, -- report statistics in a machine parsable format\n"
+" -f, -- use Force Unit Access semantics\n"
+" -i, -- treat request as invalid, for exercising stats\n"
 " -q, -- quiet mode, do not show I/O statistics\n"
-" -z, -- write zeroes using blk_aio_write_zeroes\n"
+" -u, -- with -z, allow unmapping\n"
+" -z, -- write zeroes using blk_aio_pwrite_zeroes\n"
 "\n");
 }
 
@@ -1624,9 +1424,10 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv);
 static const cmdinfo_t aio_write_cmd = {
     .name       = "aio_write",
     .cfunc      = aio_write_f,
+    .perm       = BLK_PERM_WRITE,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-Cqz] [-P pattern ] off len [len..]",
+    .args       = "[-Cfiquz] [-P pattern] off len [len..]",
     .oneline    = "asynchronously writes a number of bytes",
     .help       = aio_write_help,
 };
@@ -1636,15 +1437,22 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
     int nr_iov, c;
     int pattern = 0xcd;
     struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
+    int flags = 0;
 
     ctx->blk = blk;
-    while ((c = getopt(argc, argv, "CqP:z")) != -1) {
+    while ((c = getopt(argc, argv, "CfiqP:uz")) != -1) {
         switch (c) {
         case 'C':
-            ctx->Cflag = 1;
+            ctx->Cflag = true;
+            break;
+        case 'f':
+            flags |= BDRV_REQ_FUA;
             break;
         case 'q':
-            ctx->qflag = 1;
+            ctx->qflag = true;
+            break;
+        case 'u':
+            flags |= BDRV_REQ_MAY_UNMAP;
             break;
         case 'P':
             pattern = parse_pattern(optarg);
@@ -1653,8 +1461,13 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
                 return 0;
             }
             break;
+        case 'i':
+            printf("injecting invalid write request\n");
+            block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_WRITE);
+            g_free(ctx);
+            return 0;
         case 'z':
-            ctx->zflag = 1;
+            ctx->zflag = true;
             break;
         default:
             g_free(ctx);
@@ -1673,6 +1486,12 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
         return 0;
     }
 
+    if ((flags & BDRV_REQ_MAY_UNMAP) && !ctx->zflag) {
+        printf("-u requires -z to be specified\n");
+        g_free(ctx);
+        return 0;
+    }
+
     if (ctx->zflag && ctx->Pflag) {
         printf("-z and -P cannot be specified at the same time\n");
         g_free(ctx);
@@ -1687,24 +1506,17 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
     }
     optind++;
 
-    if (ctx->offset & 0x1ff) {
-        printf("offset %" PRId64 " is not sector aligned\n",
-               ctx->offset);
-        block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_WRITE);
-        g_free(ctx);
-        return 0;
-    }
-
     if (ctx->zflag) {
         int64_t count = cvtnum(argv[optind]);
         if (count < 0) {
             print_cvtnum_err(count, argv[optind]);
+            g_free(ctx);
             return 0;
         }
 
         ctx->qiov.size = count;
-        blk_aio_write_zeroes(blk, ctx->offset >> 9, count >> 9, 0,
-                             aio_write_done, ctx);
+        blk_aio_pwrite_zeroes(blk, ctx->offset, count, flags, aio_write_done,
+                              ctx);
     } else {
         nr_iov = argc - optind;
         ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov,
@@ -1719,8 +1531,8 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
         block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,
                          BLOCK_ACCT_WRITE);
 
-        blk_aio_writev(blk, ctx->offset >> 9, &ctx->qiov,
-                       ctx->qiov.size >> 9, aio_write_done, ctx);
+        blk_aio_pwritev(blk, ctx->offset, &ctx->qiov, flags, aio_write_done,
+                        ctx);
     }
     return 0;
 }
@@ -1755,6 +1567,7 @@ static const cmdinfo_t flush_cmd = {
 
 static int truncate_f(BlockBackend *blk, int argc, char **argv)
 {
+    Error *local_err = NULL;
     int64_t offset;
     int ret;
 
@@ -1764,9 +1577,9 @@ static int truncate_f(BlockBackend *blk, int argc, char **argv)
         return 0;
     }
 
-    ret = blk_truncate(blk, offset);
+    ret = blk_truncate(blk, offset, PREALLOC_MODE_OFF, &local_err);
     if (ret < 0) {
-        printf("truncate: %s\n", strerror(-ret));
+        error_report_err(local_err);
         return 0;
     }
 
@@ -1777,6 +1590,7 @@ static const cmdinfo_t truncate_cmd = {
     .name       = "truncate",
     .altname    = "t",
     .cfunc      = truncate_f,
+    .perm       = BLK_PERM_WRITE | BLK_PERM_RESIZE,
     .argmin     = 1,
     .argmax     = 1,
     .args       = "off",
@@ -1874,6 +1688,7 @@ static const cmdinfo_t discard_cmd = {
     .name       = "discard",
     .altname    = "d",
     .cfunc      = discard_f,
+    .perm       = BLK_PERM_WRITE,
     .argmin     = 2,
     .argmax     = -1,
     .args       = "[-Cq] off len",
@@ -1884,17 +1699,17 @@ static const cmdinfo_t discard_cmd = {
 static int discard_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timeval t1, t2;
-    int Cflag = 0, qflag = 0;
+    bool Cflag = false, qflag = false;
     int c, ret;
-    int64_t offset, count;
+    int64_t offset, bytes;
 
     while ((c = getopt(argc, argv, "Cq")) != -1) {
         switch (c) {
         case 'C':
-            Cflag = 1;
+            Cflag = true;
             break;
         case 'q':
-            qflag = 1;
+            qflag = true;
             break;
         default:
             return qemuio_command_usage(&discard_cmd);
@@ -1912,20 +1727,19 @@ static int discard_f(BlockBackend *blk, int argc, char **argv)
     }
 
     optind++;
-    count = cvtnum(argv[optind]);
-    if (count < 0) {
-        print_cvtnum_err(count, argv[optind]);
+    bytes = cvtnum(argv[optind]);
+    if (bytes < 0) {
+        print_cvtnum_err(bytes, argv[optind]);
         return 0;
-    } else if (count >> BDRV_SECTOR_BITS > INT_MAX) {
+    } else if (bytes >> BDRV_SECTOR_BITS > BDRV_REQUEST_MAX_SECTORS) {
         printf("length cannot exceed %"PRIu64", given %s\n",
-               (uint64_t)INT_MAX << BDRV_SECTOR_BITS,
+               (uint64_t)BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS,
                argv[optind]);
         return 0;
     }
 
     gettimeofday(&t1, NULL);
-    ret = blk_discard(blk, offset >> BDRV_SECTOR_BITS,
-                      count >> BDRV_SECTOR_BITS);
+    ret = blk_pdiscard(blk, offset, bytes);
     gettimeofday(&t2, NULL);
 
     if (ret < 0) {
@@ -1936,7 +1750,7 @@ static int discard_f(BlockBackend *blk, int argc, char **argv)
     /* Finally, report back -- -C gives a parsable format */
     if (!qflag) {
         t2 = tsub(t2, t1);
-        print_report("discard", &t2, offset, count, count, 1, Cflag);
+        print_report("discard", &t2, offset, bytes, bytes, 1, Cflag);
     }
 
 out:
@@ -1946,59 +1760,50 @@ out:
 static int alloc_f(BlockBackend *blk, int argc, char **argv)
 {
     BlockDriverState *bs = blk_bs(blk);
-    int64_t offset, sector_num, nb_sectors, remaining;
+    int64_t offset, start, remaining, count;
     char s1[64];
-    int num, ret;
-    int64_t sum_alloc;
+    int ret;
+    int64_t num, sum_alloc;
 
-    offset = cvtnum(argv[1]);
+    start = offset = cvtnum(argv[1]);
     if (offset < 0) {
         print_cvtnum_err(offset, argv[1]);
         return 0;
-    } else if (offset & 0x1ff) {
-        printf("offset %" PRId64 " is not sector aligned\n",
-               offset);
-        return 0;
     }
 
     if (argc == 3) {
-        nb_sectors = cvtnum(argv[2]);
-        if (nb_sectors < 0) {
-            print_cvtnum_err(nb_sectors, argv[2]);
-            return 0;
-        } else if (nb_sectors > INT_MAX) {
-            printf("length argument cannot exceed %d, given %s\n",
-                   INT_MAX, argv[2]);
+        count = cvtnum(argv[2]);
+        if (count < 0) {
+            print_cvtnum_err(count, argv[2]);
             return 0;
         }
     } else {
-        nb_sectors = 1;
+        count = BDRV_SECTOR_SIZE;
     }
 
-    remaining = nb_sectors;
+    remaining = count;
     sum_alloc = 0;
-    sector_num = offset >> 9;
     while (remaining) {
-        ret = bdrv_is_allocated(bs, sector_num, remaining, &num);
+        ret = bdrv_is_allocated(bs, offset, remaining, &num);
         if (ret < 0) {
             printf("is_allocated failed: %s\n", strerror(-ret));
             return 0;
         }
-        sector_num += num;
+        offset += num;
         remaining -= num;
         if (ret) {
             sum_alloc += num;
         }
         if (num == 0) {
-            nb_sectors -= remaining;
+            count -= remaining;
             remaining = 0;
         }
     }
 
-    cvtstr(offset, s1, sizeof(s1));
+    cvtstr(start, s1, sizeof(s1));
 
-    printf("%"PRId64"/%"PRId64" sectors allocated at offset %s\n",
-           sum_alloc, nb_sectors, s1);
+    printf("%"PRId64"/%"PRId64" bytes allocated at offset %s\n",
+           sum_alloc, count, s1);
     return 0;
 }
 
@@ -2008,19 +1813,20 @@ static const cmdinfo_t alloc_cmd = {
     .argmin     = 1,
     .argmax     = 2,
     .cfunc      = alloc_f,
-    .args       = "off [sectors]",
-    .oneline    = "checks if a sector is present in the file",
+    .args       = "offset [count]",
+    .oneline    = "checks if offset is allocated in the file",
 };
 
 
-static int map_is_allocated(BlockDriverState *bs, int64_t sector_num,
-                            int64_t nb_sectors, int64_t *pnum)
+static int map_is_allocated(BlockDriverState *bs, int64_t offset,
+                            int64_t bytes, int64_t *pnum)
 {
-    int num, num_checked;
+    int64_t num;
+    int num_checked;
     int ret, firstret;
 
-    num_checked = MIN(nb_sectors, INT_MAX);
-    ret = bdrv_is_allocated(bs, sector_num, num_checked, &num);
+    num_checked = MIN(bytes, BDRV_REQUEST_MAX_BYTES);
+    ret = bdrv_is_allocated(bs, offset, num_checked, &num);
     if (ret < 0) {
         return ret;
     }
@@ -2028,12 +1834,12 @@ static int map_is_allocated(BlockDriverState *bs, int64_t sector_num,
     firstret = ret;
     *pnum = num;
 
-    while (nb_sectors > 0 && ret == firstret) {
-        sector_num += num;
-        nb_sectors -= num;
+    while (bytes > 0 && ret == firstret) {
+        offset += num;
+        bytes -= num;
 
-        num_checked = MIN(nb_sectors, INT_MAX);
-        ret = bdrv_is_allocated(bs, sector_num, num_checked, &num);
+        num_checked = MIN(bytes, BDRV_REQUEST_MAX_BYTES);
+        ret = bdrv_is_allocated(bs, offset, num_checked, &num);
         if (ret == firstret && num) {
             *pnum += num;
         } else {
@@ -2046,25 +1852,21 @@ static int map_is_allocated(BlockDriverState *bs, int64_t sector_num,
 
 static int map_f(BlockBackend *blk, int argc, char **argv)
 {
-    int64_t offset;
-    int64_t nb_sectors, total_sectors;
-    char s1[64];
+    int64_t offset, bytes;
+    char s1[64], s2[64];
     int64_t num;
     int ret;
     const char *retstr;
 
     offset = 0;
-    total_sectors = blk_nb_sectors(blk);
-    if (total_sectors < 0) {
-        error_report("Failed to query image length: %s",
-                     strerror(-total_sectors));
+    bytes = blk_getlength(blk);
+    if (bytes < 0) {
+        error_report("Failed to query image length: %s", strerror(-bytes));
         return 0;
     }
 
-    nb_sectors = total_sectors;
-
-    do {
-        ret = map_is_allocated(blk_bs(blk), offset, nb_sectors, &num);
+    while (bytes) {
+        ret = map_is_allocated(blk_bs(blk), offset, bytes, &num);
         if (ret < 0) {
             error_report("Failed to get allocation status: %s", strerror(-ret));
             return 0;
@@ -2074,14 +1876,14 @@ static int map_f(BlockBackend *blk, int argc, char **argv)
         }
 
         retstr = ret ? "    allocated" : "not allocated";
-        cvtstr(offset << 9ULL, s1, sizeof(s1));
-        printf("[% 24" PRId64 "] % 8" PRId64 "/% 8" PRId64 " sectors %s "
-               "at offset %s (%d)\n",
-               offset << 9ULL, num, nb_sectors, retstr, s1, ret);
+        cvtstr(num, s1, sizeof(s1));
+        cvtstr(offset, s2, sizeof(s2));
+        printf("%s (0x%" PRIx64 ") bytes %s at offset %s (0x%" PRIx64 ")\n",
+               s1, num, retstr, s2, offset);
 
         offset += num;
-        nb_sectors -= num;
-    } while (offset < total_sectors);
+        bytes -= num;
+    }
 
     return 0;
 }
@@ -2105,6 +1907,7 @@ static void reopen_help(void)
 " 'reopen -o lazy-refcounts=on' - activates lazy refcount writeback on a qcow2 image\n"
 "\n"
 " -r, -- Reopen the image read-only\n"
+" -w, -- Reopen the image read-write\n"
 " -c, -- Change the cache mode to the given value\n"
 " -o, -- Changes block driver options (cf. 'open' command)\n"
 "\n");
@@ -2127,7 +1930,7 @@ static const cmdinfo_t reopen_cmd = {
        .argmin         = 0,
        .argmax         = -1,
        .cfunc          = reopen_f,
-       .args           = "[-r] [-c cache] [-o options]",
+       .args           = "[(-r|-w)] [-c cache] [-o options]",
        .oneline        = "reopens an image with new options",
        .help           = reopen_help,
 };
@@ -2140,11 +1943,12 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
     int c;
     int flags = bs->open_flags;
     bool writethrough = !blk_enable_write_cache(blk);
+    bool has_rw_option = false;
 
     BlockReopenQueue *brq;
     Error *local_err = NULL;
 
-    while ((c = getopt(argc, argv, "c:o:r")) != -1) {
+    while ((c = getopt(argc, argv, "c:o:rw")) != -1) {
         switch (c) {
         case 'c':
             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) < 0) {
@@ -2159,7 +1963,20 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
             }
             break;
         case 'r':
+            if (has_rw_option) {
+                error_report("Only one -r/-w option may be given");
+                return 0;
+            }
             flags &= ~BDRV_O_RDWR;
+            has_rw_option = true;
+            break;
+        case 'w':
+            if (has_rw_option) {
+                error_report("Only one -r/-w option may be given");
+                return 0;
+            }
+            flags |= BDRV_O_RDWR;
+            has_rw_option = true;
             break;
         default:
             qemu_opts_reset(&reopen_opts);
@@ -2180,12 +1997,27 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
         return 0;
     }
 
+    if (!(flags & BDRV_O_RDWR)) {
+        uint64_t orig_perm, orig_shared_perm;
+
+        bdrv_drain(bs);
+
+        blk_get_perm(blk, &orig_perm, &orig_shared_perm);
+        blk_set_perm(blk,
+                     orig_perm & ~(BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED),
+                     orig_shared_perm,
+                     &error_abort);
+    }
+
     qopts = qemu_opts_find(&reopen_opts, NULL);
     opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL;
     qemu_opts_reset(&reopen_opts);
 
+    bdrv_subtree_drained_begin(bs);
     brq = bdrv_reopen_queue(NULL, bs, opts, flags);
-    bdrv_reopen_multiple(brq, &local_err);
+    bdrv_reopen_multiple(bdrv_get_aio_context(bs), brq, &local_err);
+    bdrv_subtree_drained_end(bs);
+
     if (local_err) {
         error_report_err(local_err);
     } else {
@@ -2445,6 +2277,7 @@ static const cmdinfo_t help_cmd = {
 
 bool qemuio_command(BlockBackend *blk, const char *cmd)
 {
+    AioContext *ctx;
     char *input;
     const cmdinfo_t *ct;
     char **v;
@@ -2456,7 +2289,10 @@ bool qemuio_command(BlockBackend *blk, const char *cmd)
     if (c) {
         ct = find_command(v[0]);
         if (ct) {
+            ctx = blk ? blk_get_aio_context(blk) : qemu_get_aio_context();
+            aio_context_acquire(ctx);
             done = command(blk, ct, c, v);
+            aio_context_release(ctx);
         } else {
             fprintf(stderr, "command \"%s\" not found\n", v[0]);
         }
@@ -2475,7 +2311,6 @@ static void __attribute((constructor)) init_qemuio_commands(void)
     qemuio_add_command(&readv_cmd);
     qemuio_add_command(&write_cmd);
     qemuio_add_command(&writev_cmd);
-    qemuio_add_command(&multiwrite_cmd);
     qemuio_add_command(&aio_read_cmd);
     qemuio_add_command(&aio_write_cmd);
     qemuio_add_command(&aio_flush_cmd);