qemu-io: Don't use global bs in command implementations

Pass in the BlockDriverState to the command handlers instead of using
the global variable. This is an important step to make the commands
usable outside of qemu-io.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 91 insertions, 76 deletions

diff --git a/qemu-io.c b/qemu-io.c
index b4f56fc..39d7063 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -25,8 +25,8 @@
 #define CMD_NOFILE_OK   0x01
 
 char *progname;
-static BlockDriverState *bs;
 
+BlockDriverState *qemuio_bs;
 static int misalign;
 
 static int64_t cvtnum(const char *s)
@@ -63,7 +63,7 @@ static int parse_pattern(const char *arg)
  */
 
 #define MISALIGN_OFFSET     16
-static void *qemu_io_alloc(size_t len, int pattern)
+static void *qemu_io_alloc(BlockDriverState *bs, size_t len, int pattern)
 {
     void *buf;
 
@@ -136,7 +136,8 @@ static void print_report(const char *op, struct timeval *t, int64_t offset,
  * vector matching it.
  */
 static void *
-create_iovec(QEMUIOVector *qiov, char **argv, int nr_iov, int pattern)
+create_iovec(BlockDriverState *bs, QEMUIOVector *qiov, char **argv, int nr_iov,
+             int pattern)
 {
     size_t *sizes = g_new0(size_t, nr_iov);
     size_t count = 0;
@@ -172,7 +173,7 @@ create_iovec(QEMUIOVector *qiov, char **argv, int nr_iov, int pattern)
 
     qemu_iovec_init(qiov, nr_iov);
 
-    buf = p = qemu_io_alloc(count, pattern);
+    buf = p = qemu_io_alloc(bs, count, pattern);
 
     for (i = 0; i < nr_iov; i++) {
         qemu_iovec_add(qiov, p, sizes[i]);
@@ -184,7 +185,8 @@ fail:
     return buf;
 }
 
-static int do_read(char *buf, int64_t offset, int count, int *total)
+static int do_read(BlockDriverState *bs, char *buf, int64_t offset, int count,
+                   int *total)
 {
     int ret;
 
@@ -196,7 +198,8 @@ static int do_read(char *buf, int64_t offset, int count, int *total)
     return 1;
 }
 
-static int do_write(char *buf, int64_t offset, int count, int *total)
+static int do_write(BlockDriverState *bs, char *buf, int64_t offset, int count,
+                    int *total)
 {
     int ret;
 
@@ -208,7 +211,8 @@ static int do_write(char *buf, int64_t offset, int count, int *total)
     return 1;
 }
 
-static int do_pread(char *buf, int64_t offset, int count, int *total)
+static int do_pread(BlockDriverState *bs, char *buf, int64_t offset, int count,
+                    int *total)
 {
     *total = bdrv_pread(bs, offset, (uint8_t *)buf, count);
     if (*total < 0) {
@@ -217,7 +221,8 @@ static int do_pread(char *buf, int64_t offset, int count, int *total)
     return 1;
 }
 
-static int do_pwrite(char *buf, int64_t offset, int count, int *total)
+static int do_pwrite(BlockDriverState *bs, char *buf, int64_t offset, int count,
+                     int *total)
 {
     *total = bdrv_pwrite(bs, offset, (uint8_t *)buf, count);
     if (*total < 0) {
@@ -227,6 +232,7 @@ static int do_pwrite(char *buf, int64_t offset, int count, int *total)
 }
 
 typedef struct {
+    BlockDriverState *bs;
     int64_t offset;
     int count;
     int *total;
@@ -238,7 +244,7 @@ static void coroutine_fn co_write_zeroes_entry(void *opaque)
 {
     CoWriteZeroes *data = opaque;
 
-    data->ret = bdrv_co_write_zeroes(bs, data->offset / BDRV_SECTOR_SIZE,
+    data->ret = bdrv_co_write_zeroes(data->bs, data->offset / BDRV_SECTOR_SIZE,
                                      data->count / BDRV_SECTOR_SIZE);
     data->done = true;
     if (data->ret < 0) {
@@ -249,10 +255,12 @@ static void coroutine_fn co_write_zeroes_entry(void *opaque)
     *data->total = data->count;
 }
 
-static int do_co_write_zeroes(int64_t offset, int count, int *total)
+static int do_co_write_zeroes(BlockDriverState *bs, int64_t offset, int count,
+                              int *total)
 {
     Coroutine *co;
     CoWriteZeroes data = {
+        .bs     = bs,
         .offset = offset,
         .count  = count,
         .total  = total,
@@ -271,7 +279,8 @@ static int do_co_write_zeroes(int64_t offset, int count, int *total)
     }
 }
 
-static int do_write_compressed(char *buf, int64_t offset, int count, int *total)
+static int do_write_compressed(BlockDriverState *bs, char *buf, int64_t offset,
+                               int count, int *total)
 {
     int ret;
 
@@ -283,7 +292,8 @@ static int do_write_compressed(char *buf, int64_t offset, int count, int *total)
     return 1;
 }
 
-static int do_load_vmstate(char *buf, int64_t offset, int count, int *total)
+static int do_load_vmstate(BlockDriverState *bs, char *buf, int64_t offset,
+                           int count, int *total)
 {
     *total = bdrv_load_vmstate(bs, (uint8_t *)buf, offset, count);
     if (*total < 0) {
@@ -292,7 +302,8 @@ static int do_load_vmstate(char *buf, int64_t offset, int count, int *total)
     return 1;
 }
 
-static int do_save_vmstate(char *buf, int64_t offset, int count, int *total)
+static int do_save_vmstate(BlockDriverState *bs, char *buf, int64_t offset,
+                           int count, int *total)
 {
     *total = bdrv_save_vmstate(bs, (uint8_t *)buf, offset, count);
     if (*total < 0) {
@@ -307,7 +318,8 @@ static void aio_rw_done(void *opaque, int ret)
     *(int *)opaque = ret;
 }
 
-static int do_aio_readv(QEMUIOVector *qiov, int64_t offset, int *total)
+static int do_aio_readv(BlockDriverState *bs, QEMUIOVector *qiov,
+                        int64_t offset, int *total)
 {
     int async_ret = NOT_DONE;
 
@@ -321,7 +333,8 @@ static int do_aio_readv(QEMUIOVector *qiov, int64_t offset, int *total)
     return async_ret < 0 ? async_ret : 1;
 }
 
-static int do_aio_writev(QEMUIOVector *qiov, int64_t offset, int *total)
+static int do_aio_writev(BlockDriverState *bs, QEMUIOVector *qiov,
+                         int64_t offset, int *total)
 {
     int async_ret = NOT_DONE;
 
@@ -350,7 +363,8 @@ static void multiwrite_cb(void *opaque, int ret)
     }
 }
 
-static int do_aio_multiwrite(BlockRequest* reqs, int num_reqs, int *total)
+static int do_aio_multiwrite(BlockDriverState *bs, BlockRequest* reqs,
+                             int num_reqs, int *total)
 {
     int i, ret;
     struct multiwrite_async_ret async_ret = {
@@ -399,7 +413,7 @@ static void read_help(void)
 "\n");
 }
 
-static int read_f(int argc, char **argv);
+static int read_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t read_cmd = {
     .name       = "read",
@@ -412,7 +426,7 @@ static const cmdinfo_t read_cmd = {
     .help       = read_help,
 };
 
-static int read_f(int argc, char **argv)
+static int read_f(BlockDriverState *bs, int argc, char **argv)
 {
     struct timeval t1, t2;
     int Cflag = 0, pflag = 0, qflag = 0, vflag = 0;
@@ -518,15 +532,15 @@ static int read_f(int argc, char **argv)
         }
     }
 
-    buf = qemu_io_alloc(count, 0xab);
+    buf = qemu_io_alloc(bs, count, 0xab);
 
     gettimeofday(&t1, NULL);
     if (pflag) {
-        cnt = do_pread(buf, offset, count, &total);
+        cnt = do_pread(bs, buf, offset, count, &total);
     } else if (bflag) {
-        cnt = do_load_vmstate(buf, offset, count, &total);
+        cnt = do_load_vmstate(bs, buf, offset, count, &total);
     } else {
-        cnt = do_read(buf, offset, count, &total);
+        cnt = do_read(bs, buf, offset, count, &total);
     }
     gettimeofday(&t2, NULL);
 
@@ -583,7 +597,7 @@ static void readv_help(void)
 "\n");
 }
 
-static int readv_f(int argc, char **argv);
+static int readv_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t readv_cmd = {
     .name       = "readv",
@@ -595,7 +609,7 @@ static const cmdinfo_t readv_cmd = {
     .help       = readv_help,
 };
 
-static int readv_f(int argc, char **argv)
+static int readv_f(BlockDriverState *bs, int argc, char **argv)
 {
     struct timeval t1, t2;
     int Cflag = 0, qflag = 0, vflag = 0;
@@ -651,13 +665,13 @@ static int readv_f(int argc, char **argv)
     }
 
     nr_iov = argc - optind;
-    buf = create_iovec(&qiov, &argv[optind], nr_iov, 0xab);
+    buf = create_iovec(bs, &qiov, &argv[optind], nr_iov, 0xab);
     if (buf == NULL) {
         return 0;
     }
 
     gettimeofday(&t1, NULL);
-    cnt = do_aio_readv(&qiov, offset, &total);
+    cnt = do_aio_readv(bs, &qiov, offset, &total);
     gettimeofday(&t2, NULL);
 
     if (cnt < 0) {
@@ -714,7 +728,7 @@ static void write_help(void)
 "\n");
 }
 
-static int write_f(int argc, char **argv);
+static int write_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t write_cmd = {
     .name       = "write",
@@ -727,7 +741,7 @@ static const cmdinfo_t write_cmd = {
     .help       = write_help,
 };
 
-static int write_f(int argc, char **argv)
+static int write_f(BlockDriverState *bs, int argc, char **argv)
 {
     struct timeval t1, t2;
     int Cflag = 0, pflag = 0, qflag = 0, bflag = 0, Pflag = 0, zflag = 0;
@@ -814,20 +828,20 @@ static int write_f(int argc, char **argv)
     }
 
     if (!zflag) {
-        buf = qemu_io_alloc(count, pattern);
+        buf = qemu_io_alloc(bs, count, pattern);
     }
 
     gettimeofday(&t1, NULL);
     if (pflag) {
-        cnt = do_pwrite(buf, offset, count, &total);
+        cnt = do_pwrite(bs, buf, offset, count, &total);
     } else if (bflag) {
-        cnt = do_save_vmstate(buf, offset, count, &total);
+        cnt = do_save_vmstate(bs, buf, offset, count, &total);
     } else if (zflag) {
-        cnt = do_co_write_zeroes(offset, count, &total);
+        cnt = do_co_write_zeroes(bs, offset, count, &total);
     } else if (cflag) {
-        cnt = do_write_compressed(buf, offset, count, &total);
+        cnt = do_write_compressed(bs, buf, offset, count, &total);
     } else {
-        cnt = do_write(buf, offset, count, &total);
+        cnt = do_write(bs, buf, offset, count, &total);
     }
     gettimeofday(&t2, NULL);
 
@@ -870,7 +884,7 @@ writev_help(void)
 "\n");
 }
 
-static int writev_f(int argc, char **argv);
+static int writev_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t writev_cmd = {
     .name       = "writev",
@@ -882,7 +896,7 @@ static const cmdinfo_t writev_cmd = {
     .help       = writev_help,
 };
 
-static int writev_f(int argc, char **argv)
+static int writev_f(BlockDriverState *bs, int argc, char **argv)
 {
     struct timeval t1, t2;
     int Cflag = 0, qflag = 0;
@@ -932,13 +946,13 @@ static int writev_f(int argc, char **argv)
     }
 
     nr_iov = argc - optind;
-    buf = create_iovec(&qiov, &argv[optind], nr_iov, pattern);
+    buf = create_iovec(bs, &qiov, &argv[optind], nr_iov, pattern);
     if (buf == NULL) {
         return 0;
     }
 
     gettimeofday(&t1, NULL);
-    cnt = do_aio_writev(&qiov, offset, &total);
+    cnt = do_aio_writev(bs, &qiov, offset, &total);
     gettimeofday(&t2, NULL);
 
     if (cnt < 0) {
@@ -979,7 +993,7 @@ static void multiwrite_help(void)
 "\n");
 }
 
-static int multiwrite_f(int argc, char **argv);
+static int multiwrite_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t multiwrite_cmd = {
     .name       = "multiwrite",
@@ -991,7 +1005,7 @@ static const cmdinfo_t multiwrite_cmd = {
     .help       = multiwrite_help,
 };
 
-static int multiwrite_f(int argc, char **argv)
+static int multiwrite_f(BlockDriverState *bs, int argc, char **argv)
 {
     struct timeval t1, t2;
     int Cflag = 0, qflag = 0;
@@ -1072,7 +1086,7 @@ static int multiwrite_f(int argc, char **argv)
         nr_iov = j - optind;
 
         /* Build request */
-        buf[i] = create_iovec(&qiovs[i], &argv[optind], nr_iov, pattern);
+        buf[i] = create_iovec(bs, &qiovs[i], &argv[optind], nr_iov, pattern);
         if (buf[i] == NULL) {
             goto out;
         }
@@ -1090,7 +1104,7 @@ static int multiwrite_f(int argc, char **argv)
     nr_reqs = i;
 
     gettimeofday(&t1, NULL);
-    cnt = do_aio_multiwrite(reqs, nr_reqs, &total);
+    cnt = do_aio_multiwrite(bs, reqs, nr_reqs, &total);
     gettimeofday(&t2, NULL);
 
     if (cnt < 0) {
@@ -1218,7 +1232,7 @@ static void aio_read_help(void)
 "\n");
 }
 
-static int aio_read_f(int argc, char **argv);
+static int aio_read_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t aio_read_cmd = {
     .name       = "aio_read",
@@ -1230,7 +1244,7 @@ static const cmdinfo_t aio_read_cmd = {
     .help       = aio_read_help,
 };
 
-static int aio_read_f(int argc, char **argv)
+static int aio_read_f(BlockDriverState *bs, int argc, char **argv)
 {
     int nr_iov, c;
     struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
@@ -1281,7 +1295,7 @@ static int aio_read_f(int argc, char **argv)
     }
 
     nr_iov = argc - optind;
-    ctx->buf = create_iovec(&ctx->qiov, &argv[optind], nr_iov, 0xab);
+    ctx->buf = create_iovec(bs, &ctx->qiov, &argv[optind], nr_iov, 0xab);
     if (ctx->buf == NULL) {
         g_free(ctx);
         return 0;
@@ -1313,7 +1327,7 @@ static void aio_write_help(void)
 "\n");
 }
 
-static int aio_write_f(int argc, char **argv);
+static int aio_write_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t aio_write_cmd = {
     .name       = "aio_write",
@@ -1325,7 +1339,7 @@ static const cmdinfo_t aio_write_cmd = {
     .help       = aio_write_help,
 };
 
-static int aio_write_f(int argc, char **argv)
+static int aio_write_f(BlockDriverState *bs, int argc, char **argv)
 {
     int nr_iov, c;
     int pattern = 0xcd;
@@ -1373,7 +1387,7 @@ static int aio_write_f(int argc, char **argv)
     }
 
     nr_iov = argc - optind;
-    ctx->buf = create_iovec(&ctx->qiov, &argv[optind], nr_iov, pattern);
+    ctx->buf = create_iovec(bs, &ctx->qiov, &argv[optind], nr_iov, pattern);
     if (ctx->buf == NULL) {
         g_free(ctx);
         return 0;
@@ -1385,7 +1399,7 @@ static int aio_write_f(int argc, char **argv)
     return 0;
 }
 
-static int aio_flush_f(int argc, char **argv)
+static int aio_flush_f(BlockDriverState *bs, int argc, char **argv)
 {
     bdrv_drain_all();
     return 0;
@@ -1397,7 +1411,7 @@ static const cmdinfo_t aio_flush_cmd = {
     .oneline    = "completes all outstanding aio requests"
 };
 
-static int flush_f(int argc, char **argv)
+static int flush_f(BlockDriverState *bs, int argc, char **argv)
 {
     bdrv_flush(bs);
     return 0;
@@ -1410,7 +1424,7 @@ static const cmdinfo_t flush_cmd = {
     .oneline    = "flush all in-core file state to disk",
 };
 
-static int truncate_f(int argc, char **argv)
+static int truncate_f(BlockDriverState *bs, int argc, char **argv)
 {
     int64_t offset;
     int ret;
@@ -1440,7 +1454,7 @@ static const cmdinfo_t truncate_cmd = {
     .oneline    = "truncates the current file at the given offset",
 };
 
-static int length_f(int argc, char **argv)
+static int length_f(BlockDriverState *bs, int argc, char **argv)
 {
     int64_t size;
     char s1[64];
@@ -1465,7 +1479,7 @@ static const cmdinfo_t length_cmd = {
 };
 
 
-static int info_f(int argc, char **argv)
+static int info_f(BlockDriverState *bs, int argc, char **argv)
 {
     BlockDriverInfo bdi;
     char s1[64], s2[64];
@@ -1516,7 +1530,7 @@ static void discard_help(void)
 "\n");
 }
 
-static int discard_f(int argc, char **argv);
+static int discard_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t discard_cmd = {
     .name       = "discard",
@@ -1529,7 +1543,7 @@ static const cmdinfo_t discard_cmd = {
     .help       = discard_help,
 };
 
-static int discard_f(int argc, char **argv)
+static int discard_f(BlockDriverState *bs, int argc, char **argv)
 {
     struct timeval t1, t2;
     int Cflag = 0, qflag = 0;
@@ -1587,7 +1601,7 @@ out:
     return 0;
 }
 
-static int alloc_f(int argc, char **argv)
+static int alloc_f(BlockDriverState *bs, int argc, char **argv)
 {
     int64_t offset, sector_num;
     int nb_sectors, remaining;
@@ -1649,7 +1663,8 @@ static const cmdinfo_t alloc_cmd = {
 };
 
 
-static int map_is_allocated(int64_t sector_num, int64_t nb_sectors, int64_t *pnum)
+static int map_is_allocated(BlockDriverState *bs, int64_t sector_num,
+                            int64_t nb_sectors, int64_t *pnum)
 {
     int num, num_checked;
     int ret, firstret;
@@ -1679,7 +1694,7 @@ static int map_is_allocated(int64_t sector_num, int64_t nb_sectors, int64_t *pnu
     return firstret;
 }
 
-static int map_f(int argc, char **argv)
+static int map_f(BlockDriverState *bs, int argc, char **argv)
 {
     int64_t offset;
     int64_t nb_sectors;
@@ -1692,7 +1707,7 @@ static int map_f(int argc, char **argv)
     nb_sectors = bs->total_sectors;
 
     do {
-        ret = map_is_allocated(offset, nb_sectors, &num);
+        ret = map_is_allocated(bs, offset, nb_sectors, &num);
         if (ret < 0) {
             error_report("Failed to get allocation status: %s", strerror(-ret));
             return 0;
@@ -1720,7 +1735,7 @@ static const cmdinfo_t map_cmd = {
        .oneline        = "prints the allocated areas of a file",
 };
 
-static int break_f(int argc, char **argv)
+static int break_f(BlockDriverState *bs, int argc, char **argv)
 {
     int ret;
 
@@ -1742,7 +1757,7 @@ static const cmdinfo_t break_cmd = {
                          "request as tag",
 };
 
-static int resume_f(int argc, char **argv)
+static int resume_f(BlockDriverState *bs, int argc, char **argv)
 {
     int ret;
 
@@ -1763,7 +1778,7 @@ static const cmdinfo_t resume_cmd = {
        .oneline        = "resumes the request tagged as tag",
 };
 
-static int wait_break_f(int argc, char **argv)
+static int wait_break_f(BlockDriverState *bs, int argc, char **argv)
 {
     while (!bdrv_debug_is_suspended(bs, argv[1])) {
         qemu_aio_wait();
@@ -1781,7 +1796,7 @@ static const cmdinfo_t wait_break_cmd = {
        .oneline        = "waits for the suspension of a request",
 };
 
-static int abort_f(int argc, char **argv)
+static int abort_f(BlockDriverState *bs, int argc, char **argv)
 {
     abort();
 }
@@ -1793,10 +1808,10 @@ static const cmdinfo_t abort_cmd = {
        .oneline        = "simulate a program crash using abort(3)",
 };
 
-static int close_f(int argc, char **argv)
+static int close_f(BlockDriverState *bs, int argc, char **argv)
 {
     bdrv_delete(bs);
-    bs = NULL;
+    qemuio_bs = NULL;
     return 0;
 }
 
@@ -1809,23 +1824,23 @@ static const cmdinfo_t close_cmd = {
 
 static int openfile(char *name, int flags, int growable)
 {
-    if (bs) {
+    if (qemuio_bs) {
         fprintf(stderr, "file open already, try 'help close'\n");
         return 1;
     }
 
     if (growable) {
-        if (bdrv_file_open(&bs, name, NULL, flags)) {
+        if (bdrv_file_open(&qemuio_bs, name, NULL, flags)) {
             fprintf(stderr, "%s: can't open device %s\n", progname, name);
             return 1;
         }
     } else {
-        bs = bdrv_new("hda");
+        qemuio_bs = bdrv_new("hda");
 
-        if (bdrv_open(bs, name, NULL, flags, NULL) < 0) {
+        if (bdrv_open(qemuio_bs, name, NULL, flags, NULL) < 0) {
             fprintf(stderr, "%s: can't open device %s\n", progname, name);
-            bdrv_delete(bs);
-            bs = NULL;
+            bdrv_delete(qemuio_bs);
+            qemuio_bs = NULL;
             return 1;
         }
     }
@@ -1850,7 +1865,7 @@ static void open_help(void)
 "\n");
 }
 
-static int open_f(int argc, char **argv);
+static int open_f(BlockDriverState *bs, int argc, char **argv);
 
 static const cmdinfo_t open_cmd = {
     .name       = "open",
@@ -1864,7 +1879,7 @@ static const cmdinfo_t open_cmd = {
     .help       = open_help,
 };
 
-static int open_f(int argc, char **argv)
+static int open_f(BlockDriverState *bs, int argc, char **argv)
 {
     int flags = 0;
     int readonly = 0;
@@ -1901,7 +1916,7 @@ static int open_f(int argc, char **argv)
     return openfile(argv[optind], flags, growable);
 }
 
-static int init_check_command(const cmdinfo_t *ct)
+static int init_check_command(BlockDriverState *bs, const cmdinfo_t *ct)
 {
     if (ct->flags & CMD_FLAG_GLOBAL) {
         return 1;
@@ -2064,8 +2079,8 @@ int main(int argc, char **argv)
      */
     bdrv_drain_all();
 
-    if (bs) {
-        bdrv_delete(bs);
+    if (qemuio_bs) {
+        bdrv_delete(qemuio_bs);
     }
     return 0;
 }