Commit Graph

4794 Commits

Author SHA1 Message Date
Vladimir Sementsov-Ogievskiy
795d946d07 nbd: Use ERRP_GUARD()
If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix several such cases, e.g. in nbd_read().

This commit is generated by command

    sed -n '/^Network Block Device (NBD)$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-8-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]
2020-07-10 15:18:09 +02:00
Markus Armbruster
386f6c07d2 error: Avoid error_propagate() after migrate_add_blocker()
When migrate_add_blocker(blocker, &errp) is followed by
error_propagate(errp, err), we can often just as well do
migrate_add_blocker(..., errp).

Do that with this Coccinelle script:

    @@
    expression blocker, err, errp;
    expression ret;
    @@
    -    ret = migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    ret = migrate_add_blocker(blocker, errp);
    +    if (ret < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

    @@
    expression blocker, err, errp;
    @@
    -    migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    if (migrate_add_blocker(blocker, errp) < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

Double-check @err is not used afterwards.  Dereferencing it would be
use after free, but checking whether it's null would be legitimate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-43-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
b11a093c60 qapi: Smooth another visitor error checking pattern
Convert

    visit_type_FOO(v, ..., &ptr, &err);
    ...
    if (err) {
        ...
    }

to

    visit_type_FOO(v, ..., &ptr, errp);
    ...
    if (!ptr) {
        ...
    }

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
4bc6d7ee0e block/parallels: Simplify parallels_open() after previous commit
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-39-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
a5f9b9df25 error: Reduce unnecessary error propagation
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away, even when we need to keep error_propagate() for other
error paths.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-38-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
992861fb1e error: Eliminate error_propagate() manually
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous two commits did that for sufficiently simple
cases with Coccinelle.  Do it for several more manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-37-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
af175e85f9 error: Eliminate error_propagate() with Coccinelle, part 2
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
dcfe480544 error: Avoid unnecessary error_propagate() after error_setg()
Replace

    error_setg(&err, ...);
    error_propagate(errp, err);

by

    error_setg(errp, ...);

Related pattern:

    if (...) {
        error_setg(&err, ...);
        goto out;
    }
    ...
 out:
    error_propagate(errp, err);
    return;

When all paths to label out are that way, replace by

    if (...) {
        error_setg(errp, ...);
        return;
    }

and delete the label along with the error_propagate().

When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.

    foo(..., &err);
    if (err) {
        goto out;
    }
    ...
    bar(..., &err);
 out:
    error_propagate(errp, err);
    return;

move the error_propagate() to where it's needed, like

    if (...) {
        foo(..., &err);
        error_propagate(errp, err);
        return;
    }
    ...
    bar(..., errp);
    return;

and transform the error_setg() as above.

In some places, the transformation results in obviously unnecessary
error_propagate().  The next few commits will eliminate them.

Bonus: the elimination of gotos will make later patches in this series
easier to review.

Candidates for conversion tracked down with this Coccinelle script:

    @@
    identifier err, errp;
    expression list args;
    @@
    -    error_setg(&err, args);
    +    error_setg(errp, args);
         ... when != err
         error_propagate(errp, err);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
14217038bc qapi: Use returned bool to check for failure, manual part
The previous commit used Coccinelle to convert from checking the Error
object to checking the return value.  Convert a few more manually.
Also tweak control flow in places to conform to the conventional "if
error bail out" pattern.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-20-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
62a35aaa31 qapi: Use returned bool to check for failure, Coccinelle part
The previous commit enables conversion of

    visit_foo(..., &err);
    if (err) {
        ...
    }

to

    if (!visit_foo(..., errp)) {
        ...
    }

for visitor functions that now return true / false on success / error.
Coccinelle script:

    @@
    identifier fun =~ "check_list|input_type_enum|lv_start_struct|lv_type_bool|lv_type_int64|lv_type_str|lv_type_uint64|output_type_enum|parse_type_bool|parse_type_int64|parse_type_null|parse_type_number|parse_type_size|parse_type_str|parse_type_uint64|print_type_bool|print_type_int64|print_type_null|print_type_number|print_type_size|print_type_str|print_type_uint64|qapi_clone_start_alternate|qapi_clone_start_list|qapi_clone_start_struct|qapi_clone_type_bool|qapi_clone_type_int64|qapi_clone_type_null|qapi_clone_type_number|qapi_clone_type_str|qapi_clone_type_uint64|qapi_dealloc_start_list|qapi_dealloc_start_struct|qapi_dealloc_type_anything|qapi_dealloc_type_bool|qapi_dealloc_type_int64|qapi_dealloc_type_null|qapi_dealloc_type_number|qapi_dealloc_type_str|qapi_dealloc_type_uint64|qobject_input_check_list|qobject_input_check_struct|qobject_input_start_alternate|qobject_input_start_list|qobject_input_start_struct|qobject_input_type_any|qobject_input_type_bool|qobject_input_type_bool_keyval|qobject_input_type_int64|qobject_input_type_int64_keyval|qobject_input_type_null|qobject_input_type_number|qobject_input_type_number_keyval|qobject_input_type_size_keyval|qobject_input_type_str|qobject_input_type_str_keyval|qobject_input_type_uint64|qobject_input_type_uint64_keyval|qobject_output_start_list|qobject_output_start_struct|qobject_output_type_any|qobject_output_type_bool|qobject_output_type_int64|qobject_output_type_null|qobject_output_type_number|qobject_output_type_str|qobject_output_type_uint64|start_list|visit_check_list|visit_check_struct|visit_start_alternate|visit_start_list|visit_start_struct|visit_type_.*";
    expression list args;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err);
    -    if (err)
    +    if (!fun(args, &err))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-19-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
235e59cf03 qemu-option: Use returned bool to check for failure
The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for QemuOpts functions that now return true / false on success /
error.  Coccinelle script:

    @@
    identifier fun = {
        opts_do_parse, parse_option_bool, parse_option_number,
        parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
        qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
        qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
        qemu_opts_validate
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]
2020-07-10 15:17:35 +02:00
Markus Armbruster
c6ecec43b2 qemu-option: Check return value instead of @err where convenient
Convert uses like

    opts = qemu_opts_create(..., &err);
    if (err) {
        ...
    }

to

    opts = qemu_opts_create(..., errp);
    if (!opts) {
        ...
    }

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Note that we can't drop parallels_open()'s error_propagate() here.  We
continue to execute it even in the converted case.  It's a no-op then:
local_err is null.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-8-armbru@redhat.com>
2020-07-10 15:01:06 +02:00
Eric Blake
365fed5111 qed: Simplify backing reads
The other four drivers that support backing files (qcow, qcow2,
parallels, vmdk) all rely on the block layer to populate zeroes when
reading beyond EOF of a short backing file.  We can simplify the qed
code by doing likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200528094405.145708-11-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
a2adbbf603 block: drop unallocated_blocks_are_zero
Currently this field only set by qed and qcow2. But in fact, all
backing-supporting formats (parallels, qcow, qcow2, qed, vmdk) share
these semantics: on unallocated blocks, if there is no backing file they
just memset the buffer with zeroes.

So, document this behavior for .supports_backing and drop
.unallocated_blocks_are_zero

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-10-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
cdf9ebf18f block/vhdx: drop unallocated_blocks_are_zero
vhdx doesn't have .bdrv_co_block_status handler, so DATA|ALLOCATED is
always assumed for it in bdrv_co_block_status().
unallocated_blocks_are_zero is useless (it doesn't affect the only user
of the field: bdrv_co_block_status()), drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-9-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
ac9185603e block/file-posix: drop unallocated_blocks_are_zero
raw_co_block_status() in block/file-posix.c never returns 0, so
unallocated_blocks_are_zero is useless (it doesn't affect the only user
of the field: bdrv_co_block_status()). Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-8-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
32d293c8c6 block/iscsi: drop unallocated_blocks_are_zero
We set bdi->unallocated_blocks_are_zero = iscsilun->lbprz, but
iscsi_co_block_status doesn't return 0 in case of iscsilun->lbprz, it
returns ZERO when appropriate. So actually unallocated_blocks_are_zero
is useless (it doesn't affect the only user of the field:
bdrv_co_block_status()). Drop it now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-7-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
74036395ea block/crypto: drop unallocated_blocks_are_zero
It's false by default, no needs to set it. We are going to drop this
variable at all, so drop it now here, it doesn't hurt.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-6-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
2c060c0f50 block/vpc: return ZERO block-status when appropriate
In case when get_image_offset() returns -1, we do zero out the
corresponding chunk of qiov. So, this should be reported as ZERO.

Note that this changes visible output of "qemu-img map --output=json"
and "qemu-io -c map" commands. For qemu-img map, the change is obvious:
we just mark as zero what is really zero. For qemu-io it's less
obvious: what was unallocated now is allocated.

There is an inconsistency in understanding of unallocated regions in
Qemu: backing-supporting format-drivers return 0 block-status to report
go-to-backing logic for this area. Some protocol-drivers (iscsi) return
0 to report fs-unallocated-non-zero status (i.e., don't occupy space on
disk, read result is undefined).

BDRV_BLOCK_ALLOCATED is defined as something more close to
go-to-backing logic. Still it is calculated as ZERO | DATA, so 0 from
iscsi is treated as unallocated. It doesn't influence backing-chain
behavior, as iscsi can't have backing file. But it does influence
"qemu-io -c map".

We should solve this inconsistency at some future point. Now, let's
just make backing-not-supporting format drivers (vdi in the previous
patch and vpc now) to behave more like backing-supporting drivers
and not report 0 block-status. More over, returning ZERO status is
absolutely valid thing, and again, corresponds to how the other
format-drivers (backing-supporting) work.

After block-status update, it never reports 0, so setting
unallocated_blocks_are_zero doesn't make sense (as the only user of it
is bdrv_co_block_status and it checks unallocated_blocks_are_zero only
for unallocated areas). Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-5-vsementsov@virtuozzo.com>
[mreitz: qemu-io -c map as used by iotest 146 now reports everything as
         allocated; in order to make the test do something useful, we
         use qemu-img map --output=json now]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:32:38 +02:00
Vladimir Sementsov-Ogievskiy
2ea0332f42 block/vdi: return ZERO block-status when appropriate
In case of !VDI_IS_ALLOCATED[], we do zero out the corresponding chunk
of qiov. So, this should be reported as ZERO.

Note that this changes visible output of "qemu-img map --output=json"
and "qemu-io -c map" commands. For qemu-img map, the change is obvious:
we just mark as zero what is really zero. For qemu-io it's less
obvious: what was unallocated now is allocated.

There is an inconsistency in understanding of unallocated regions in
Qemu: backing-supporting format-drivers return 0 block-status to report
go-to-backing logic for this area. Some protocol-drivers (iscsi) return
0 to report fs-unallocated-non-zero status (i.e., don't occupy space on
disk, read result is undefined).

BDRV_BLOCK_ALLOCATED is defined as something more close to
go-to-backing logic. Still it is calculated as ZERO | DATA, so 0 from
iscsi is treated as unallocated. It doesn't influence backing-chain
behavior, as iscsi can't have backing file. But it does influence
"qemu-io -c map".

We should solve this inconsistency at some future point. Now, let's
just make backing-not-supporting format drivers (vdi at this patch and
vpc with the following) to behave more like backing-supporting drivers
and not report 0 block-status. More over, returning ZERO status is
absolutely valid thing, and again, corresponds to how the other
format-drivers (backing-supporting) work.

After block-status update, it never reports 0, so setting
unallocated_blocks_are_zero doesn't make sense (as the only user of it
is bdrv_co_block_status and it checks unallocated_blocks_are_zero only
for unallocated areas). Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-4-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Vladimir Sementsov-Ogievskiy
7b1efe996c block: inline bdrv_unallocated_blocks_are_zero()
The function has only one user: bdrv_co_block_status(). Inline it to
simplify reviewing of the following patches, which will finally drop
unallocated_blocks_are_zero field too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
8ea1613d91 block/qcow2: implement blockdev-amend
Currently the implementation only supports amending the encryption
options, unlike the qemu-img version

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-14-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
30da9dd88a block/crypto: implement blockdev-amend
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-13-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
ced914d0ab block/core: add generic infrastructure for x-blockdev-amend qmp command
blockdev-amend will be used similiar to blockdev-create
to allow on the fly changes of the structure of the format based block devices.

Current plan is to first support encryption keyslot management for luks
based formats (raw and embedded in qcow2)

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200608094030.670121-12-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
90766d9db9 block/qcow2: extend qemu-img amend interface with crypto options
Now that we have all the infrastructure in place,
wire it in the qcow2 driver and expose this to the user.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-9-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
bbfdae91fb block/crypto: implement the encryption key management
This implements the encryption key management using the generic code in
qcrypto layer and exposes it to the user via qemu-img

This code adds another 'write_func' because the initialization
write_func works directly on the underlying file, and amend
works on instance of luks device.

This commit also adds a 'hack/workaround' I and Kevin Wolf (thanks)
made to make the driver both support write sharing (to avoid breaking the users),
and be safe against concurrent  metadata update (the keyslots)

Eventually the write sharing for luks driver will be deprecated
and removed together with this hack.

The hack is that we ask (as a format driver) for BLK_PERM_CONSISTENT_READ
and then when we want to update the keys, we unshare that permission.
So if someone else has the image open, even readonly, encryption
key update will fail gracefully.

Also thanks to Daniel Berrange for the idea of
unsharing read, rather that write permission which allows
to avoid cases when the other user had opened the image read-only.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-8-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
e0d0ddc591 block/crypto: rename two functions
rename the write_func to create_write_func, and init_func to create_init_func.
This is preparation for other write_func that will be used to update the encryption keys.

No functional changes

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200608094030.670121-7-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
0b6786a9c1 block/amend: refactor qcow2 amend options
Some qcow2 create options can't be used for amend.
Remove them from the qcow2 create options and add generic logic to detect
such options in qemu-img

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[mreitz: Dropped some iotests reference output hunks that became
         unnecessary thanks to
         "iotests: Make _filter_img_create more active"]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200625125548.870061-12-mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
df373fb0a3 block/amend: separate amend and create options for qemu-img
Some options are only useful for creation
(or hard to be amended, like cluster size for qcow2), while some other
options are only useful for amend, like upcoming keyslot management
options for luks

Since currently only qcow2 supports amend, move all its options
to a common macro and then include it in each action option list.

In future it might be useful to remove some options which are
not supported anyway from amend list, which currently
cause an error message if amended.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-5-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
a3579bfa0a block/amend: add 'force' option
'force' option will be used for some unsafe amend operations.

This includes things like erasing last keyslot in luks based formats
(which destroys the data, unless the master key is backed up
by external means), but that _might_ be desired result.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-4-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
43cbd06df2 qcrypto/core: add generic infrastructure for crypto options amendment
This will be used first to implement luks keyslot management.

block_crypto_amend_opts_init will be used to convert
qemu-img cmdline to QCryptoBlockAmendOptions

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200608094030.670121-2-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Alberto Garcia
a5675f3901 qcow2: Fix preallocation on images with unaligned sizes
When resizing an image with qcow2_co_truncate() using the falloc or
full preallocation modes the code assumes that both the old and new
sizes are cluster-aligned.

There are two problems with this:

  1) The calculation of how many clusters are involved does not always
     get the right result.

     Example: creating a 60KB image and resizing it (with
     preallocation=full) to 80KB won't allocate the second cluster.

  2) No copy-on-write is performed, so in the previous example if
     there is a backing file then the first 60KB of the first cluster
     won't be filled with data from the backing file.

This patch fixes both issues.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200617140036.20311-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:33:06 +02:00
Vladimir Sementsov-Ogievskiy
e8de7ba9ea block/block-copy: block_copy_dirty_clusters: fix failure check
ret may be > 0 on success path at this point. Fix assertion, which may
crash currently.

Fixes: 4ce5dd3e9b
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200526181347.489557-1-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:33:06 +02:00
Kevin Wolf
3dfa23b9ef vvfat: Fix array_remove_slice()
array_remove_slice() calls array_roll() with array->next - 1 as the
destination index. This is only correct for count == 1, otherwise we're
writing past the end of the array. array->next - count would be correct.

However, this is the only place ever calling array_roll(), so this
rather complicated operation isn't even necessary.

Fix the problem and simplify the code by replacing it with a single
memmove() call. array_roll() can now be removed.

Reported-by: Nathan Huckleberry <nhuck15@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200623175534.38286-3-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-03 09:37:03 +02:00
Kevin Wolf
c79e243ed6 vvfat: Check that updated filenames are valid
FAT allows only a restricted set of characters in file names, and for
some of the illegal characters, it's actually important that we catch
them: If filenames can contain '/', the guest can construct filenames
containing "../" and escape from the assigned vvfat directory. The same
problem could arise if ".." was ever accepted as a literal filename.

Fix this by adding a check that all filenames are valid in
check_directory_consistency().

Reported-by: Nathan Huckleberry <nhuck15@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200623175534.38286-2-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-03 09:37:03 +02:00
Stefan Hajnoczi
7838c67f22 block/nvme: support nested aio_poll()
QEMU block drivers are supposed to support aio_poll() from I/O
completion callback functions. This means completion processing must be
re-entrant.

The standard approach is to schedule a BH during completion processing
and cancel it at the end of processing. If aio_poll() is invoked by a
callback function then the BH will run. The BH continues the suspended
completion processing.

All of this means that request A's cb() can synchronously wait for
request B to complete. Previously the nvme block driver would hang
because it didn't process completions from nested aio_poll().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-id: 20200617132201.1832152-8-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Stefan Hajnoczi
b75fd5f554 block/nvme: keep BDRVNVMeState pointer in NVMeQueuePair
Passing around both BDRVNVMeState and NVMeQueuePair is unwieldy. Reduce
the number of function arguments by keeping the BDRVNVMeState pointer in
NVMeQueuePair. This will come in handly when a BH is introduced in a
later patch and only one argument can be passed to it.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200617132201.1832152-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Stefan Hajnoczi
a5db74f324 block/nvme: clarify that free_req_queue is protected by q->lock
Existing users access free_req_queue under q->lock. Document this.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200617132201.1832152-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Stefan Hajnoczi
1086e95da1 block/nvme: switch to a NVMeRequest freelist
There are three issues with the current NVMeRequest->busy field:
1. The busy field is accidentally accessed outside q->lock when request
   submission fails.
2. Waiters on free_req_queue are not woken when a request is returned
   early due to submission failure.
2. Finding a free request involves scanning all requests. This makes
   request submission O(n^2).

Switch to an O(1) freelist that is always accessed under the lock.

Also differentiate between NVME_QUEUE_SIZE, the actual SQ/CQ size, and
NVME_NUM_REQS, the number of usable requests. This makes the code
simpler than using NVME_QUEUE_SIZE everywhere and having to keep in mind
that one slot is reserved.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-id: 20200617132201.1832152-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Stefan Hajnoczi
04b3fb39c8 block/nvme: don't access CQE after moving cq.head
Do not access a CQE after incrementing q->cq.head and releasing q->lock.
It is unlikely that this causes problems in practice but it's a latent
bug.

The reason why it should be safe at the moment is that completion
processing is not re-entrant and the CQ doorbell isn't written until the
end of nvme_process_completion().

Make this change now because QEMU expects completion processing to be
re-entrant and later patches will do that.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200617132201.1832152-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Stefan Hajnoczi
d38253cf8b block/nvme: drop tautologous assertion
nvme_process_completion() explicitly checks cid so the assertion that
follows is always true:

  if (cid == 0 || cid > NVME_QUEUE_SIZE) {
      ...
      continue;
  }
  assert(cid <= NVME_QUEUE_SIZE);

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200617132201.1832152-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Stefan Hajnoczi
2446e0e2e9 block/nvme: poll queues without q->lock
A lot of CPU time is spent simply locking/unlocking q->lock during
polling. Check for completion outside the lock to make q->lock disappear
from the profile.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-id: 20200617132201.1832152-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:08 +01:00
Eric Blake
f17d684770 qcow2: Tweak comments on qcow2_get_persistent_dirty_bitmap_size
For now, we don't have persistent bitmaps in any other formats, but
that might not be true in the future.  Make it obvious that our
incoming parameter is not necessarily a qcow2 image, and therefore is
limited to just the bdrv_dirty_bitmap_* API calls (rather than probing
into qcow2 internals).

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200608190821.3293867-1-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-06-17 14:53:39 +02:00
Eric Blake
e37adbebd1 block: Refactor subdirectory recursion during make
Rather than listing block/monitor from the top-level Makefile.objs, we
should instead list monitor from block/Makefile.objs.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Fixes: bb4e58c613
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200608173339.3244211-1-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-06-17 14:53:39 +02:00
Eric Blake
5c86bdf120 block: Call attention to truncation of long NBD exports
Commit 93676c88 relaxed our NBD client code to request export names up
to the NBD protocol maximum of 4096 bytes without NUL terminator, even
though the block layer can't store anything longer than 4096 bytes
including NUL terminator for display to the user.  Since this means
there are some export names where we have to truncate things, we can
at least try to make the truncation a bit more obvious for the user.
Note that in spite of the truncated display name, we can still
communicate with an NBD server using such a long export name; this was
deemed nicer than refusing to even connect to such a server (since the
server may not be under our control, and since determining our actual
length limits gets tricky when nbd://host:port/export and
nbd+unix:///export?socket=/path are themselves variable-length
expansions beyond the export name but count towards the block layer
name length).

Reported-by: Xueqiang Wei <xuwei@redhat.com>
Fixes: https://bugzilla.redhat.com/1843684
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200610163741.3745251-3-eblake@redhat.com>
2020-06-10 12:58:59 -05:00
Vladimir Sementsov-Ogievskiy
7d2410cea1 block: Factor out bdrv_run_co()
We have a few bdrv_*() functions that can either spawn a new coroutine
and wait for it with BDRV_POLL_WHILE() or use a fastpath if they are
alreeady running in a coroutine. All of them duplicate basically the
same code.

Factor the common code into a new function bdrv_run_co().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20200520144901.16589-1-vsementsov@virtuozzo.com
   [Factor out bdrv_run_co_entry too]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-05 09:54:48 +01:00
Stefano Garzarella
769335ecb1 io_uring: use io_uring_cq_ready() to check for ready cqes
In qemu_luring_poll_cb() we are not using the cqe peeked from the
CQ ring. We are using io_uring_peek_cqe() only to see if there
are cqes ready, so we can replace it with io_uring_cq_ready().

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20200519134942.118178-1-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-05 09:54:48 +01:00
Stefano Garzarella
b4e44c9944 io_uring: retry io_uring_submit() if it fails with errno=EINTR
As recently documented [1], io_uring_enter(2) syscall can return an
error (errno=EINTR) if the operation was interrupted by a delivery
of a signal before it could complete.

This should happen when IORING_ENTER_GETEVENTS flag is used, for
example during io_uring_submit_and_wait() or during io_uring_submit()
when IORING_SETUP_IOPOLL is enabled.

We shouldn't have this problem for now, but it's better to prevent it.

[1] 344355ec66

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20200519133041.112138-1-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-05 09:54:48 +01:00
Eric Blake
5d72c68b49 qcow2: Expose bitmaps' size during measure
It's useful to know how much space can be occupied by qcow2 persistent
bitmaps, even though such metadata is unrelated to the guest-visible
data.  Report this value as an additional QMP field, present when
measuring an existing image and output format that both support
bitmaps.  Update iotest 178 and 190 to updated output, as well as new
coverage in 190 demonstrating non-zero values made possible with the
recently-added qemu-img bitmap command (see 3b51ab4b).

The new 'bitmaps size:' field is displayed automatically as part of
'qemu-img measure' any time it is present in QMP (that is, any time
both the source image being measured and destination format support
bitmaps, even if the measurement is 0 because there are no bitmaps
present).  If the field is absent, it means that no bitmaps can be
copied (source, destination, or both lack bitmaps, including when
measuring based on size rather than on a source image).  This behavior
is compatible with an upcoming patch adding 'qemu-img convert
--bitmaps': that command will fail in the same situations where this
patch omits the field.

The addition of a new field demonstrates why we should always
zero-initialize qapi C structs; while the qcow2 driver still fully
populates all fields, the raw and crypto drivers had to be tweaked to
avoid uninitialized data.

Consideration was also given towards having a 'qemu-img measure
--bitmaps' which errors out when bitmaps are not possible, and
otherwise sums the bitmaps into the existing allocation totals rather
than displaying as a separate field, as a potential convenience
factor.  But this was ultimately decided to be more complexity than
necessary when the QMP interface was sufficient enough with bitmaps
remaining a separate field.

See also: https://bugzilla.redhat.com/1779904

Reported-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200521192137.1120211-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-28 13:16:16 -05:00