We are gradually moving away from sector-based interfaces, towards
byte-based. In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.
Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated. For now,
the io.c layer still assert()s that all callers are sector-aligned
on input and that *pnum is sector-aligned on return to the caller,
but that can be relaxed when a later patch implements byte-based
block status. Therefore, this code adds usages like
DIV_ROUND_UP(,BDRV_SECTOR_SIZE) to callers that still want aligned
values, where the call might reasonbly give non-aligned results
in the future; on the other hand, no rounding is needed for callers
that should just continue to work with byte alignment.
For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_is_allocated(). But
some code, particularly bdrv_commit(), gets a lot simpler because it
no longer has to mess with sectors; also, it is now possible to pass
NULL if the caller does not care how much of the image is allocated
beyond the initial offset. Leave comments where we can further
simplify once a later patch eliminates the need for sector-aligned
requests through bdrv_is_allocated().
For ease of review, bdrv_is_allocated_above() will be tackled
separately.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Change the internal
loop iteration of backups to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are cluster-aligned).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function (no semantic change).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Continue by converting
the public interface to backup jobs (no semantic change), including
a change to CowRequest to track by bytes instead of cluster indices.
Note that this does not change the difference between the public
interface (starting point, and size of the subsequent range) and
the internal interface (starting and end points).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Xie Changlong <xiechanglong@cmss.chinamobile.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Continue by converting an
internal structure (no semantic change), and all references to
tracking progress. Drop a redundant local variable bytes_per_cluster.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that the last user [mirror_iteration()] has converted to using
bytes, we no longer need a function to round sectors to clusters.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Change the internal
loop iteration of mirroring to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are both sector-aligned and multiples of the granularity). Drop
the now-unused mirror_clip_sectors().
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function, preserving all existing semantics, and adding one more
assertion that things are still sector-aligned (so that conversions
to sectors in mirror_read_complete don't need to round).
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function (no semantic change), and add mirror_clip_bytes() as a
counterpart to mirror_clip_sectors(). Some of the conversion is
a bit tricky, requiring temporaries to convert between units; it
will be cleared up in a following patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Rather than having a void function that modifies its input
in-place as the output, change the signature to reduce a layer
of indirection and return the result.
Suggested-by: John Snow <jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function (no semantic change).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Continue by converting an
internal structure (no semantic change), and all references to the
buffer size.
Add an assertion that our use of s->granularity >> BDRV_SECTOR_BITS
(necessary for interaction with sector-based dirty bitmaps, until
a later patch converts those to be byte-based) does not suffer from
truncation problems.
[checkpatch has a false positive on use of MIN() in this patch]
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Change the internal
loop iteration of committing to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are sector-aligned).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Start by converting an
internal function (no semantic change).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Change the internal
loop iteration of streaming to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are sector-aligned).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
stream_complete() skips the work of rewriting the backing file if
the job was cancelled, if data->reached_end is false, or if there
was an error detected (non-zero data->ret) during the streaming.
But note that in stream_run(), data->reached_end is only set if the
loop ran to completion, and data->ret is only 0 in two cases:
either the loop ran to completion (possibly by cancellation, but
stream_complete checks for that), or we took an early goto out
because there is no bs->backing. Thus, we can preserve the same
semantics without the use of reached_end, by merely checking for
bs->backing (and logically, if there was no backing file, streaming
is a no-op, so there is no backing file to rewrite).
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Start by converting an
internal function (no semantic change).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Upcoming patches are going to switch to byte-based interfaces
instead of sector-based. Even worse, trace_backup_do_cow_enter()
had a weird mix of cluster and sector indices.
The trace interface is low enough that there are no stability
guarantees, and therefore nothing wrong with changing our units,
even in cases like trace_backup_do_cow_skip() where we are not
changing the trace output. So make the tracing uniformly use
bytes.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The user interface specifies job rate limits in bytes/second.
It's pointless to have our internal representation track things
in sectors/second, particularly since we want to move away from
sector-based interfaces.
Fix up a doc typo found while verifying that the ratelimit
code handles the scaling difference.
Repetition of expressions like 'n * BDRV_SECTOR_SIZE' will be
cleaned up later when functions are converted to iterate over
images by bytes rather than by sectors.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
According to specification:
"'MSWIN4.1' is the recommanded setting, because it is the setting least likely
to cause compatibility problems. If you want to put something else in here,
that is your option, but the result may be that some FAT drivers might not
recognize the volume."
Specification: "FAT: General overview of on-disk format" v1.03, page 9
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Specification: "FAT: General overview of on-disk format" v1.03, page 23
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
FAT12/FAT16 root directory is two sectors in size, which allows only 512 directory entries.
Prevent QEMU startup if too much files exist, instead of overflowing root directory.
Also introduce variable root_entries, which will be required for FAT32.
Fixes: https://bugs.launchpad.net/qemu/+bug/1599539/comments/4
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
More specifically:
- try without numeric-tail only if LFN didn't have invalid short chars
- start at ~1 (instead of ~0)
- handle case if numeric tail is more than one char (ie > 10)
Windows 9x Scandisk doesn't see anymore mismatches between short file names and
long file names for non-ASCII filenames.
Specification: "FAT: General overview of on-disk format" v1.03, page 31
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
More specifically, create short name from filename and change blacklist of
invalid chars to whitelist of valid chars.
Windows 9x also now correctly see long file names of filenames containing a space,
but Scandisk still complains about mismatch between SFN and LFN.
[kwolf: Build fix for this intermediate patch (it included declarations
for variables that are only used in the next patch) ]
Specification: "FAT: General overview of on-disk format" v1.03, pages 30-31
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Assume that input filename is encoded as UTF-8, so correctly create UTF-16 encoding.
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
readdir() doesn't always return . and .. entries at first and in that order.
This leads to not creating them at first in the directory, which raises some
errors on file system checking utilities like MS-DOS Scandisk.
Specification: "FAT: General overview of on-disk format" v1.03, page 25
Fixes: https://bugs.launchpad.net/qemu/+bug/1599539
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Specification: "FAT: General overview of on-disk format" v1.03, pages 11-13
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
- offset_to_bootsector is the number of sectors up to FAT bootsector
- offset_to_fat is the number of sectors up to first File Allocation Table
- offset_to_root_dir is the number of sectors up to root directory sector
Replace first_sectors_number - 1 by offset_to_bootsector.
Replace first_sectors_number by offset_to_fat.
Replace faked_sectors by offset_to_rootdir.
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
MODE_FAKED and MODE_RENAMED are not and were never used.
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This was a complete mess. On 2299 indented lines:
- 1329 were with spaces only
- 617 with tabulations only
- 353 with spaces and tabulations
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
- bs->total_sectors is the number of sectors of the whole disk
- s->sector_count is the number of sectors of the FAT partition
This fixes the following assert in qemu-img map:
qemu-img.c:2641: get_block_status: Assertion `nb_sectors' failed.
This also fixes an infinite loop in qemu-img convert.
Fixes: 4480e0f924
Fixes: https://bugs.launchpad.net/qemu/+bug/1599539
Cc: qemu-stable@nongnu.org
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Without a passthrough status of BDRV_BLOCK_RAW, anything wrapped by
blkdebug appears 100% allocated as data. Better is treating it the
same as the underlying file being wrapped.
Update iotest 177 for the new expected output.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The lone caller that cares about a return of BDRV_BLOCK_RAW
(namely, io.c:bdrv_co_get_block_status) completely replaces the
return value, so there is no point in passing BDRV_BLOCK_DATA.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We document that *file is valid if the return is not an error and
includes BDRV_BLOCK_OFFSET_VALID, but forgot to obey this contract
when a driver (such as blkdebug) lacks a callback. Messed up in
commit 67a0fd2 (v2.6), when we added the file parameter.
Enhance qemu-iotest 177 to cover this, using a sequence that would
print garbage or even SEGV, because it was dererefencing through
uninitialized memory. [The resulting test output shows that we
have less-than-ideal block status from the blkdebug driver, but
that's a separate fix coming up soon.]
Setting *file on all paths that return BDRV_BLOCK_OFFSET_VALID is
enough to fix the crash, but we can go one step further: always
setting *file, even on error, means that a broken caller that
blindly dereferences file without checking for error is now more
likely to get a reliable SEGV instead of randomly acting on garbage,
making it easier to diagnose such buggy callers. Adding an
assertion that file is set where expected doesn't hurt either.
CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When attaching the NBD QIOChannel to an AioContext, the TLS channel should
be used, not the underlying socket channel. This is because, trivially,
the TLS channel will be the one that we read/write to and thus the one
that will get the qio_channel_yield() call.
Fixes: ff82911cd3
Cc: qemu-stable@nongnu.org
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Tested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When we have a BDS with unallocated clusters, but asking the status
of its underlying bs->file or backing layer encounters an end-of-file
condition, we know that the rest of the unallocated area will read as
zeroes. However, pre-patch, this required two separate calls to
bdrv_get_block_status(), as the first call stops at the point where
the underlying file ends. Thanks to BDRV_BLOCK_EOF, we can now widen
the results of the primary status if the secondary status already
includes BDRV_BLOCK_ZERO.
In turn, this fixes a TODO mentioned in iotest 154, where we can now
see that all sectors in a partial cluster at the end of a file read
as zero when coupling the shorter backing file's status along with our
knowledge that the remaining sectors came from an unallocated cluster.
Also, note that the loop in bdrv_co_get_block_status_above() had an
inefficent exit: in cases where the active layer sets BDRV_BLOCK_ZERO
but does NOT set BDRV_BLOCK_ALLOCATED (namely, where we know we read
zeroes merely because our unallocated clusters lie beyond the backing
file's shorter length), we still ended up probing the backing layer
even though we already had a good answer.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170505021500.19315-3-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Just as the block layer already sets BDRV_BLOCK_ALLOCATED as a
shortcut for subsequent operations, there are also some optimizations
that are made easier if we can quickly tell that *pnum will advance
us to the end of a file, via a new BDRV_BLOCK_EOF which gets set
by the block layer.
This just plumbs up the new bit; subsequent patches will make use
of it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170505021500.19315-2-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
uri_parse(...)->scheme may be NULL. In fact, probably every field may be
NULL, and the callers do test this for all of the other fields but not
for scheme (except for block/gluster.c; block/vxhs.c does not access
that field at all).
We can easily fix this by using g_strcmp0() instead of strcmp().
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170613205726.13544-1-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The bs->exact_filename field may not be sufficient to store the full
blkverify node filename. In this case, we should not generate a filename
at all instead of an unusable one.
Cc: qemu-stable@nongnu.org
Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170613172006.19685-3-mreitz@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The bs->exact_filename field may not be sufficient to store the full
blkdebug node filename. In this case, we should not generate a filename
at all instead of an unusable one.
Cc: qemu-stable@nongnu.org
Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170613172006.19685-2-mreitz@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related
functions (and some others) to 'int bytes', as they both refer to bytes.
This helps with code legibility.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
All functions that are marked coroutine_fn can directly call the
bdrv_co_* version of functions instead of going through the wrapper.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Now that we stay in coroutine context for the whole request when doing
reads or writes, we can add coroutine_fn annotations to many functions
that can do I/O or yield directly.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This fixes the last place where we degraded from AIO to actual blocking
synchronous I/O requests. Putting it into a coroutine means that instead
of blocking, the coroutine simply yields while doing I/O.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Now that we process a request in the same coroutine from beginning to
end and don't drop out of it any more, we can look like a proper
coroutine-based driver and simply call qed_aio_next_io() and get a
return value from it instead of spawning an additional coroutine that
reenters the parent when it's done.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Now that we're running in coroutine context, the ad-hoc serialisation
code (which drops a request that has to wait out of coroutine context)
can be replaced by a CoQueue.
This means that when we resume a serialised request, it is running in
coroutine context again and its I/O isn't blocking any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Most of the qed code is now synchronous and matches the coroutine model.
One notable exception is the serialisation between requests which can
still schedule a callback. Before we can replace this with coroutine
locks, let's convert the driver's external interfaces to the coroutine
versions.
We need to be careful to handle both requests that call the completion
callback directly from the calling coroutine (i.e. fully synchronous
code) and requests that involve some callback, so that we need to yield
and wait for the completion callback coming from outside the coroutine.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Instead of calling itself recursively as the last thing, just convert
qed_aio_next_io() into a loop.
This patch is best reviewed with 'git show -w' because most of it is
just whitespace changes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Don't recurse into qed_aio_next_io() and qed_aio_complete() here, but
just return an error code and let the caller handle it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Don't recurse into qed_aio_next_io() and qed_aio_complete() here, but
just return an error code and let the caller handle it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Don't recurse into qed_aio_next_io() and qed_aio_complete() here, but
just return an error code and let the caller handle it.
While refactoring qed_aio_write_alloc() to accomodate the change,
qed_aio_write_zero_cluster() ended up with a single line, so I chose to
inline that line and remove the function completely.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Don't recurse into qed_aio_next_io() and qed_aio_complete() here, but
just return an error code and let the caller handle it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Don't recurse into qed_aio_next_io() and qed_aio_complete() here, but
just return an error code and let the caller handle it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Don't recurse into qed_aio_next_io() and qed_aio_complete() here, but
just return an error code and let the caller handle it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
qed_commit_l2_update() is unconditionally called at the end of
qed_aio_write_l1_update(). Inline it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
The GenericCB infrastructure isn't used any more. Remove it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
With this change, qed_aio_write_prefill() and qed_aio_write_postfill()
collapse into a single function. This is reflected by a rename of the
combined function to qed_aio_write_cow().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Instead of passing the return value to a callback, return it to the
caller so that the callback can be inlined there.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
The qed driver serialises allocating write requests. When the active
allocation is finished, the AIO callback is called, but after this, the
next allocating request is immediately processed instead of leaving the
coroutine. Resuming another allocation request in the same request
coroutine means that the request now runs in the wrong coroutine.
The following is one of the possible effects of this: The completed
request will generally reenter its request coroutine in a bottom half,
expecting that it completes the request in bdrv_driver_pwritev().
However, if the second request actually yielded before leaving the
coroutine, the reused request coroutine is in an entirely different
place and is reentered prematurely. Not a good idea.
Let's make sure that we exit the coroutine after completing the first
request by resuming the next allocating request only with a bottom
half.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
We already have functions for doing these calculations, so let's use
them instead of doing everything by hand. This makes the code a bit
more readable.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the guest tries to write data that results on the allocation of a
new cluster, instead of writing the guest data first and then the data
from the COW regions, write everything together using one single I/O
operation.
This can improve the write performance by 25% or more, depending on
several factors such as the media type, the cluster size and the I/O
request size.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of passing a single buffer pointer to do_perform_cow_write(),
pass a QEMUIOVector. This will allow us to merge the write requests
for the COW regions and the actual data into a single one.
Although do_perform_cow_read() does not strictly need to change its
API, we're doing it here as well for consistency.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reading both COW regions requires two separate requests, but it's
perfectly possible to merge them and perform only one. This generally
improves performance, particularly on rotating disk drives. The
downside is that the data in the middle region is read but discarded.
This patch takes a conservative approach and only merges reads when
the size of the middle region is <= 16KB.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch splits do_perform_cow() into three separate functions to
read, encrypt and write the COW regions.
perform_cow() can now read both regions first, then encrypt them and
finally write them to disk. The memory allocation is also done in
this function now, using one single buffer large enough to hold both
regions.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of calling perform_cow() twice with a different COW region
each time, call it just once and make perform_cow() handle both
regions.
This patch simply moves code around. The next one will do the actual
reordering of the COW operations.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Qcow2COWRegion has two attributes:
- The offset of the COW region from the start of the first cluster
touched by the I/O request. Since it's always going to be positive
and the maximum request size is at most INT_MAX, we can use a
regular unsigned int to store this offset.
- The size of the COW region in bytes. This is guaranteed to be >= 0,
so we should use an unsigned type instead.
In x86_64 this reduces the size of Qcow2COWRegion from 16 to 8 bytes.
It will also help keep some assertions simpler now that we know that
there are no negative numbers.
The prototype of do_perform_cow() is also updated to reflect these
changes.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are using the return value of qcow2_encrypt_sectors() to detect
problems but we are throwing away the returned Error since we have no
way to report it to the user. Therefore we can simply get rid of the
local Error variable and pass NULL instead.
Alternatively we could try to figure out a way to pass the original
error instead of simply returning -EIO, but that would be more
invasive, so let's keep the current approach.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There used to be throttle_timers_{detach,attach}_aio_context() calls
in bdrv_set_aio_context(), but since 7ca7f0f6db
they are now in blk_set_aio_context().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Calling aio_poll() directly may have been fine previously, but this is
the future, man! The difference between an aio_poll() loop and
BDRV_POLL_WHILE() is that BDRV_POLL_WHILE() releases the AioContext
around aio_poll().
This allows the IOThread to run fd handlers or BHs to complete the
request. Failure to release the AioContext causes deadlocks.
Using BDRV_POLL_WHILE() partially fixes a 'savevm' hang with -object
iothread.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Call bdrv_inc/dec_in_flight() for vmstate reads/writes. This seems
unnecessary at first glance because vmstate reads/writes are done
synchronously while the guest is stopped. But we need the bdrv_wakeup()
in bdrv_dec_in_flight() so the main loop sees request completion.
Besides, it's cleaner to count vmstate reads/writes like ordinary
read/write requests.
The bdrv_wakeup() partially fixes a 'savevm' hang with -object iothread.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
commit_complete() can't assume that after its block_job_completed() the
job is actually immediately freed; someone else may still be holding
references. In this case, the op blockers on the intermediate nodes make
the graph reconfiguration in the completion code fail.
Call block_job_remove_all_bdrv() manually so that we know for sure that
any blockers on intermediate nodes are given up.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
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Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-06-09-v2' into staging
QAPI patches for 2017-06-09
# gpg: Signature made Tue 20 Jun 2017 13:31:39 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653
* remotes/armbru/tags/pull-qapi-2017-06-09-v2: (41 commits)
tests/qdict: check more get_try_int() cases
console: use get_uint() for "head" property
i386/cpu: use get_uint() for "min-level"/"min-xlevel" properties
numa: use get_uint() for "size" property
pnv-core: use get_uint() for "core-pir" property
pvpanic: use get_uint() for "ioport" property
auxbus: use get_uint() for "addr" property
arm: use get_uint() for "mp-affinity" property
xen: use get_uint() for "max-ram-below-4g" property
pc: use get_uint() for "hpet-intcap" property
pc: use get_uint() for "apic-id" property
pc: use get_uint() for "iobase" property
acpi: use get_uint() for "pci-hole*" properties
acpi: use get_uint() for various acpi properties
acpi: use get_uint() for "acpi-pcihp-io*" properties
platform-bus: use get_uint() for "addr" property
bcm2835_fb: use {get, set}_uint() for "vcram-size" and "vcram-base"
aspeed: use {set, get}_uint() for "ram-size" property
pcihp: use get_uint() for "bsel" property
pc-dimm: make "size" property uint64
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Version: GnuPG v2
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Merge remote-tracking branch 'remotes/famz/tags/docker-and-block-pull-request' into staging
# gpg: Signature made Fri 16 Jun 2017 01:18:46 BST
# gpg: using RSA key 0xCA35624C6A9171C6
# gpg: Good signature from "Fam Zheng <famz@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg: It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 5003 7CB7 9706 0F76 F021 AD56 CA35 624C 6A91 71C6
* remotes/famz/tags/docker-and-block-pull-request: (23 commits)
block: make accounting thread-safe
block: split BlockAcctStats creation and setup
block: introduce block_account_one_io
block: protect modification of dirty bitmaps with a mutex
migration/block: reset dirty bitmap before reading
block: introduce dirty_bitmap_mutex
block: protect tracked_requests and flush_queue with reqs_lock
block: access write_gen with atomics
block: use Stat64 for wr_highest_offset
util: add stats64 module
throttle-groups: protect throttled requests with a CoMutex
throttle-groups: do not use qemu_co_enter_next
throttle-groups: only start one coroutine from drained_begin
block: access io_plugged with atomic ops
block: access wakeup with atomic ops
block: access serialising_in_flight with atomic ops
block: access io_limits_disabled with atomic ops
block: access quiesce_counter with atomic ops
block: access copy_on_read with atomic ops
docker: Add flex and bison to centos6 image
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We would like to use a same QObject type to represent numbers, whether
they are int, uint, or floats. Getters will allow some compatibility
between the various types if the number fits other representations.
Add a few more tests while at it.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170607163635.17635-7-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[parse_stats_intervals() simplified a bit, comment in
test_visitor_in_int_overflow() tidied up, suppress bogus warnings]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
I'm not trying too hard yet. Later, with multiqueue support,
this may cause mutex contention or cacheline bouncing.
Cc: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-20-pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
block_acct_destroy is called unconditionally in blk_delete, but there is
no BlockAcctStats function that is called unconditionally in blk_new.
Split block_acct_init in two, so that it will be possible to create a
QemuMutex in block_acct_init and destroy it in block_acct_cleanup.
Cc: Alberto Garcia <berto@igalia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-19-pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
This is the common code to account operations that produced actual I/O.
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-18-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
It protects only the list of dirty bitmaps; in the next patch we will
also protect their content.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-15-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Another possibility is to use tg->lock, which we're holding anyway in
both schedule_next_request and throttle_group_co_io_limits_intercept.
This would require open-coding the CoQueue however, so I've chosen this
alternative.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-10-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Prepare for removing this function; always restart throttled requests
from coroutine context. This will matter when restarting throttled
requests will have to acquire a CoMutex.
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-9-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Starting all waiting coroutines from bdrv_drain_all is unnecessary;
throttle_group_co_io_limits_intercept calls schedule_next_request as
soon as the coroutine restarts, which in turn will restart the next
request if possible.
If we only start the first request and let the coroutines dance from
there the code is simpler and there is more reuse between
throttle_group_config, throttle_group_restart_blk and timer_cb. The
next patch will benefit from this.
We also stop accessing from throttle_group_restart_blk the
blkp->throttled_reqs CoQueues even when there was no
attached throttling group. This worked but is not pretty.
The only thing that can interrupt the dance is the QEMU_CLOCK_VIRTUAL
timer when switching from one block device to the next, because the
timer is set to "now + 1" but QEMU_CLOCK_VIRTUAL might not be running.
Set that timer to point in the present ("now") rather than the future
and things work.
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-8-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Eric Blake
Hervé Poussineau
Paolo Bonzini
Max Reitz
Manos Pitsidianakis
Kevin Wolf
Alberto Garcia
Stefan Hajnoczi
Peter Maydell
Marc-André Lureau