Commit b04b6b6e authored by Fam Zheng's avatar Fam Zheng Committed by Kevin Wolf
Browse files

block: Print its file name if backing file opening failed 



If backing file doesn't exist, the error message is confusing and
misleading:

    $ qemu /tmp/a.qcow2
    qemu: could not open disk image /tmp/a.qcow2: Could not open file: No
    such file or directory

But...

    $ ls /tmp/a.qcow2
    /tmp/a.qcow2

    $ qemu-img info /tmp/a.qcow2
    image: /tmp/a.qcow2
    file format: qcow2
    virtual size: 8.0G (8589934592 bytes)
    disk size: 196K
    cluster_size: 65536
    backing file: /tmp/b.qcow2

Because...

    $ ls /tmp/b.qcow2
    ls: cannot access /tmp/b.qcow2: No such file or directory

This is not intuitive. It's better to have the missing file's name in
the error message. With this patch:

    $ qemu-io -c 'read 0 512' /tmp/a.qcow2
    qemu-io: can't open device /tmp/a.qcow2: Could not open backing
    file: Could not open '/stor/vm/arch.raw': No such file or directory
    no file open, try 'help open'

Which is a little bit better.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 5c5432e7

block.c

+3 −1
Original line number Diff line number Diff line
@@ -1009,7 +1009,9 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) 
        bdrv_unref(bs->backing_hd);

        bs->backing_hd = NULL;

        bs->open_flags |= BDRV_O_NO_BACKING;

        error_propagate(errp, local_err);

        error_setg(errp, "Could not open backing file: %s",

                   error_get_pretty(local_err));

        error_free(local_err);

        return ret;

    }

    pstrcpy(bs->backing_file, sizeof(bs->backing_file),

block/raw-posix.c

+0 −1
Original line number Diff line number Diff line
@@ -310,7 +310,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, 
        if (ret == -EROFS) {

            ret = -EACCES;

        }

        error_setg_errno(errp, -ret, "Could not open file");

        goto fail;

    }

    s->fd = fd;

block/raw-win32.c

+0 −1
Original line number Diff line number Diff line
@@ -280,7 +280,6 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags, 
        } else {

            ret = -EINVAL;

        }

        error_setg_errno(errp, -ret, "Could not open file");

        goto fail;

    }

tests/qemu-iotests/051.out

+1 −1
Original line number Diff line number Diff line
@@ -226,6 +226,6 @@ Testing: -drive file=foo:bar 
QEMU_PROG: -drive file=foo:bar: could not open disk image foo:bar: Unknown protocol



Testing: -drive file.filename=foo:bar

QEMU_PROG: -drive file.filename=foo:bar: could not open disk image ide0-hd0: Could not open file: No such file or directory

QEMU_PROG: -drive file.filename=foo:bar: could not open disk image ide0-hd0: Could not open 'foo:bar': No such file or directory



*** done

tests/qemu-iotests/069.out

+1 −1
Original line number Diff line number Diff line
@@ -4,5 +4,5 @@ QA output created by 069 


Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=131072 

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=131072 backing_file='TEST_DIR/t.IMGFMT.base' 

qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open file: No such file or directory

qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory

*** done