rbd: switch from pipe to QEMUBH completion notification

rbd callbacks are called from non-QEMU threads.  Up until now a pipe was
used to signal completion back to the QEMU iothread.

The pipe writer code handles EAGAIN using select(2).  The select(2) API
is not scalable since fd_set size is static.  FD_SET() can write beyond
the end of fd_set if the file descriptor number is too high.  (QEMU's
main loop uses poll(2) to avoid this issue with select(2).)

Since the pipe itself is quite clumsy to use and QEMUBH is now
thread-safe, just schedule a BH from the rbd callback function.  This
way we can simplify I/O completion in addition to eliminating the
potential FD_SET() crash when file descriptor numbers become too high.

Crash scenario: QEMU already has 1024 file descriptors open.  Hotplug an
rbd drive and get the pipe writer to take the select(2) code path.

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Tested-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-iotests: Introduce _unsupported_imgopts

Introduce _unsupported_imgopts that causes _notrun for specific image
options.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-iotests: Add _unsupported_imgopts for vmdk subformats

Some cases are not applicable for vmdk subformats those don't support
certain features, e.g. backing file, and some others can't run on
mult-file image, e.g. monolithicFlat. This adds declaration in test
cases to skip them automatically, so that iotests on vmdk can go
more smoothly (without manually picking of cases for each subformat).

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-iotests: Clean up all extents for vmdk

This modifies _cleanup_test_img to remove all the extent files listed by
"qemu-img info"'s format specific information.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block/iscsi: return -ENOMEM if an async call fails immediately

if an async libiscsi call fails directly it can only be due
to an out of memory condition. All other errors are returned
through the callback.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
gluster: Convert aio routines into coroutines

Convert the read, write, flush and discard implementations from aio-based
ones to coroutine based ones.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
gluster: Implement .bdrv_co_write_zeroes for gluster

Support .bdrv_co_write_zeroes() from gluster driver by using GlusterFS API
glfs_zerofill() that off-loads the writing of zeroes to GlusterFS server.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
gluster: Add support for creating zero-filled image

GlusterFS supports creation of zero-filled file on GlusterFS volume
by means of an API called glfs_zerofill(). Use this API from QEMU to
create an image that is filled with zeroes by using the preallocation
option of qemu-img.

qemu-img create gluster://server/volume/image -o preallocation=full 10G

The allowed values for preallocation are 'full' and 'off'. By default
preallocation is off and image is not zero-filled.

glfs_zerofill() offloads the writing of zeroes to the server and if
the storage supports SCSI WRITESAME, GlusterFS server can issue
BLKZEROOUT ioctl to achieve the zeroing.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
sheepdog: fix clone operation by 'qemu-img create -b'

We should pass base_inode->vdi_id to base_vdi_id of SheepdogVdiReq so that sheep
can create a clone instead a fresh volume.

This fixes following command:

qemu-create -b sheepdog:base sheepdog:clone

so users can boot sheepdog:clone as a normal volume.

Cc: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Liu Yuan <namei.unix@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qtest: Fix the bug about disable vnc causes "make check" fail

When we disable vnc from "./configure", QEMU can't use the vnc option.
So qtest can't use the "vnc -none ", otherwise "make check" fails.
If QEMU uses "-display none", "-vnc none" is excrescent, So we just need to drop it.

Signed-off-by: Kewei Yu <keweihk@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
docs: qcow2 compat=1.1 is now the default

Commit 9117b47717ad208b12786ce88eacb013f9b3dd1c ("qcow2: Change default
for new images to compat=1.1") changed the default qcow2 image format
version but forgot to update qemu-doc.texi and qemu-img.texi.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
vmdk: Fix big flat extent IO

Local variable "n" as int64_t avoids overflow with large sector number
calculation. See test case change for failure case.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
readline: decouple readline from the monitor

Make the readline.c functionality reusable.  Instead of calling
monitor_printf() and monitor_flush() directly, invoke function pointers
provided by the user.

This way readline.c does not know about Monitor and other users will be
able to make use of readline.c.

Note that there is already an "opaque" argument to the ReadLineFunc
callback.  Consistently call it "readline_opaque" from now on to
distinguish from the ReadLinePrintfFunc/ReadLineFlushFunc "opaque"
argument.

I also dropped the printf macro trickery since it's now highly unlikely
that anyone modifying readline.c would call printf(3) directly.  We no
longer need this protection.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
readline: move readline to a generic location

Now that the monitor and readline are decoupled, readline.h no longer
belongs in include/monitor/.  Put the header into include/qemu/.

Move the source file into util/ so it can be linked as part of
libqemuutil.a.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
osdep: add qemu_set_tty_echo()

Using stdin with readline.c requires disabling echo and line buffering.
Add a portable wrapper to set the terminal attributes under Linux and
Windows.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-io: use readline.c

Use readline.c for command-line history.  There was support for GNU
Readline and BSD Editline but it was never compiled in.  Since QEMU has
its own readline.c, just use that when qemu-io runs with stdin attached
to a terminal.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-io: add command completion

Autocomplete qemu-io commands at the interactive prompt.

Note this only completes command names and not their options.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blkdebug: Use errp for read_config()

Use an Error variable in the read_config() function.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blkdebug: Don't require sophisticated filename

If the filename is not prefixed by "blkdebug:" in
blkdebug_parse_filename(), the blkdebug driver was not selected through
that protocol prefix, but by an explicit command line option
(file.driver=blkdebug or something similar). Contrary to the current
reaction, this is not a problem at all; we just need to store the
filename (in the x-image option) and can go on; the user just has to
manually specify the config option.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qdict: Add qdict_array_split()

This function splits a QDict consisting of entries prefixed by
incrementally enumerated indices into a QList of QDicts.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>