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2020-07-14qemu-img: Deprecate use of -b without -FEric Blake1-1/+26
Creating an image that requires format probing of the backing image is potentially unsafe (we've had several CVEs over the years based on probes leaking information to the guest on a subsequent boot, although these days tools like libvirt are aware of the issue enough to prevent the worst effects). For example, if our probing algorithm ever changes, or if other tools like libvirt determine a different probe result than we do, then subsequent use of that backing file under a different format will present corrupted data to the guest. Fortunately, the worst effects occur only when the backing image is originally raw, and we at least prevent commit into a probed raw backing file that would change its probed type. Still, it is worth starting a deprecation clock so that future qemu-img can refuse to create backing chains that would rely on probing, to encourage clients to avoid unsafe practices. Most warnings are intentionally emitted from bdrv_img_create() in the block layer, but qemu-img convert uses bdrv_create() which cannot emit its own warning without causing spurious warnings on other code paths. In the end, all command-line image creation or backing file rewriting now performs a check. Furthermore, if we probe a backing file as non-raw, then it is safe to explicitly record that result (rather than relying on future probes); only where we probe a raw image do we care about further warnings to the user when using such an image (for example, commits into a probed-raw backing file are prevented), to help them improve their tooling. But whether or not we make the probe results explicit, we still warn the user to remind them to upgrade their workflow to supply -F always. iotest 114 specifically wants to create an unsafe image for later amendment rather than defaulting to our new default of recording a probed format, so it needs an update. While touching it, expand it to cover all of the various warnings enabled by this patch. iotest 301 also shows a change to qcow messages. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-11-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14block: Add support to warn on backing file change without formatEric Blake1-3/+10
For now, this is a mechanical addition; all callers pass false. But the next patch will use it to improve 'qemu-img rebase -u' when selecting a backing file with no format. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com> Message-Id: <20200706203954.341758-10-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14block: Error if backing file fails during creation without -uEric Blake1-10/+2
Back in commit 6e6e55f5 (Jul 2017, v2.10), we tweaked the code to warn if the backing file could not be opened but the user gave a size, unless the user also passes the -u option to bypass the open of the backing file. As one common reason for failure to open the backing file is when there is mismatch in the requested backing format in relation to what the backing file actually contains, we actually want to open the backing file and ensure that it has the right format in as many cases as possible. iotest 301 for qcow demonstrates how detecting explicit format mismatch is useful to prevent the creation of an image that would probe differently than the user requested. Now is the time to finally turn the warning an error, as promised. Note that the original warning was added prior to our documentation of an official deprecation policy (eb22aeca, also Jul 2017), and because the warning didn't mention the word "deprecated", we never actually remembered to document it as such. But the warning has been around long enough that I don't see prolonging it another two releases. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-7-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14qemu-img: Flush stdout before before potential stderr messagesEric Blake1-0/+1
During 'qemu-img create ... 2>&1', if --quiet is not in force, we can end up with buffered I/O in stdout that was produced before failure, but which appears in output after failure. This is confusing; the fix is to flush stdout prior to attempting anything that might produce an error message. Several iotests demonstrate the resulting ordering change now that the merged outputs now reflect chronology. (An even better fix would be to avoid printf from within block.c altogether, but that's much more invasive...) Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-2-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-10error: Reduce unnecessary error propagationMarkus Armbruster1-1/+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, 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>
2020-07-10error: Eliminate error_propagate() with Coccinelle, part 2Markus Armbruster1-4/+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>
2020-07-10error: Eliminate error_propagate() with Coccinelle, part 1Markus Armbruster1-2/+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>
2020-07-10block: Avoid error accumulation in bdrv_img_create()Markus Armbruster1-2/+2
When creating an image fails because the format doesn't support option "backing_file" or "backing_fmt", bdrv_img_create() first has qemu_opt_set() put a generic error into @local_err, then puts the real error into @errp with error_setg(), and then propagates the former to the latter, which throws away the generic error. A bit complicated, but works. Now that qemu_opt_set() returns a useful value, we can simply ignore the generic error instead. 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: <20200707160613.848843-16-armbru@redhat.com>
2020-07-10qemu-option: Use returned bool to check for failureMarkus Armbruster1-10/+6
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]
2020-07-06block: inline bdrv_unallocated_blocks_are_zero()Vladimir Sementsov-Ogievskiy1-15/+0
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>
2020-07-06block/amend: add 'force' optionMaxim Levitsky1-1/+3
'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>
2020-06-10block: Call attention to truncation of long NBD exportsEric Blake1-2/+5
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>
2020-05-18block: Drop @child_class from bdrv_child_perm()Max Reitz1-23/+16
Implementations should decide the necessary permissions based on @role. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-35-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Drop child_fileMax Reitz1-37/+2
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-33-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Drop bdrv_format_default_perms()Max Reitz1-19/+0
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-32-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make bdrv_filter_default_perms() staticMax Reitz1-6/+11
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-31-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use child_of_bds in remaining placesMax Reitz1-1/+2
Replace child_file by child_of_bds in all remaining places (excluding tests). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-28-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Drop child_backingMax Reitz1-57/+3
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-25-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make backing files child_of_bds childrenMax Reitz1-6/+20
Make all parents of backing files pass the appropriate BdrvChildRole. By doing so, we can switch their BdrvChildClass over to the generic child_of_bds, which will do the right thing when given a correct BdrvChildRole. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-24-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Drop child_formatMax Reitz1-29/+0
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-23-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add bdrv_default_perms()Max Reitz1-0/+32
This callback can be used by BDSs that use child_of_bds with the appropriate BdrvChildRole for their children. Also, make bdrv_format_default_perms() use it for child_of_bds children (just a temporary solution until we can drop bdrv_format_default_perms() altogether). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-20-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Relax *perms_for_storage for data childrenMax Reitz1-10/+48
We can be less restrictive about pure data children than those with metadata on them, so let bdrv_default_perms_for_storage() handle metadata children differently from pure data children. As explained in the code, the restrictions on metadata children are strictly stricter than those for pure data children, so in theory we just have to distinguish between pure-data and all other storage children (pure metadata or data+metadata). In practice, that is not obvious, though, so we have two independent code paths for metadata and for data children, and data+metadata children will go through both (without the path for data children doing anything meaningful). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-19-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pull out bdrv_default_perms_for_storage()Max Reitz1-25/+46
Right now, bdrv_format_default_perms() is used by format parents (generally). We want to switch to a model where most parents use a single BdrvChildClass, which then decides the permissions based on the child role. To do so, we have to split bdrv_format_default_perms() into separate functions for each such role. Note that bdrv_default_perms_for_storage() currently handles all DATA | METADATA children. A follow-up patch is going to split it further into one function for each case. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-18-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pull out bdrv_default_perms_for_cow()Max Reitz1-22/+40
Right now, bdrv_format_default_perms() is used by format parents (generally). We want to switch to a model where most parents use a single BdrvChildClass, which then decides the permissions based on the child role. To do so, we have to split bdrv_format_default_perms() into separate functions for each such role. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-17-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Distinguish paths in *_format_default_permsMax Reitz1-6/+13
bdrv_format_default_perms() has one code path for backing files, and one for storage files. We want to pull them out into their own functions, so make sure they are completely distinct before so the next patches will be a bit cleaner. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-16-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add child_of_bdsMax Reitz1-0/+24
Any current user of child_file, child_format, and child_backing can and should use this generic BdrvChildClass instead, as it can handle all of these cases. However, to be able to do so, the users must pass the appropriate BdrvChildRole when the child is created/attached. (The following commits will take care of that.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-15-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Unify bdrv_child_cb_detach()Max Reitz1-7/+20
Make bdrv_child_cb_detach() call bdrv_backing_detach() for children with a COW role (and drop the reverse call from bdrv_backing_detach()), so it can be used for any child (with a proper role set). Because so far no child has a proper role set, we need a temporary new callback for child_backing.detach that ensures bdrv_backing_detach() is called for all COW children that do not have their role set yet. (Also, move bdrv_child_cb_detach() down to group it with bdrv_inherited_options() and bdrv_child_cb_attach().) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-14-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Unify bdrv_child_cb_attach()Max Reitz1-7/+20
Make bdrv_child_cb_attach() call bdrv_backing_attach() for children with a COW role (and drop the reverse call from bdrv_backing_attach()), so it can be used for any child (with a proper role set). Because so far no child has a proper role set, we need a temporary new callback for child_backing.attach that ensures bdrv_backing_attach() is called for all COW children that do not have their role set yet. (Also, move bdrv_child_cb_attach() down to group it with bdrv_inherited_options().) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-13-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use bdrv_inherited_options()Max Reitz1-52/+19
Let child_file's, child_format's, and child_backing's .inherit_options() implementations fall back to bdrv_inherited_options() to show that it would really work for all of these cases, if only the parents passed the appropriate BdrvChildRole and parent_is_format values. (Also, make bdrv_open_inherit(), the only place to explicitly call bdrv_backing_options(), call bdrv_inherited_options() instead.) This patch should incur only two visible changes, both for child_format children, both of which are effectively bug fixes: First, they no longer have discard=unmap set by default. This reason it was set is because bdrv_inherited_fmt_options() fell through to bdrv_protocol_options(), and that set it because "format drivers take care to send flushes and respect unmap policy". None of the drivers that use child_format for their children (quorum and blkverify) are format drivers, though, so this reasoning does not apply here. Second, they no longer have BDRV_O_NO_IO force-cleared. child_format was used solely for children that do not store any metadata and as such will not be accessed by their parents as long as those parents do not receive I/O themselves. Thus, such children should inherit BDRV_O_NO_IO. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-12-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add generic bdrv_inherited_options()Max Reitz1-0/+81
After the series this patch belongs to, we want to have a common BdrvChildClass that encompasses all of child_file, child_format, and child_backing. Such a single class needs a single .inherit_options() implementation, and this patch introduces it. The next patch will show how the existing implementations can fall back to it just by passing appropriate BdrvChildRole and parent_is_format values. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-11-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Rename bdrv_inherited_options()Max Reitz1-4/+4
The other two .inherit_options implementations specify exactly for what case they are used in their name, so do it for this one as well. (The actual intention behind this patch is to follow it up with a generic bdrv_inherited_options() that works for all three cases.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-10-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass parent_is_format to .inherit_options()Max Reitz1-10/+27
We plan to unify the generic .inherit_options() functions. The resulting common function will need to decide whether to force-enable format probing, force-disable it, or leave it as-is. To make this decision, it will need to know whether the parent node is a format node or not (because we never want format probing if the parent is a format node already (except for the backing chain)). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-9-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole to .inherit_options()Max Reitz1-16/+24
For now, all callers (effectively) pass 0 and no callee evaluates thie value. Later patches will change both. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-8-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole to bdrv_child_perm()Max Reitz1-10/+12
For now, all callers pass 0 and no callee evaluates this value. Later patches will change both. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-7-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add BdrvChildRole to BdrvChildMax Reitz1-3/+8
For now, it is always set to 0. Later patches in this series will ensure that all callers pass an appropriate combination of flags. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Rename BdrvChildRole to BdrvChildClassMax Reitz1-69/+73
This structure nearly only contains parent callbacks for child state changes. It cannot really reflect a child's role, because different roles may overlap (as we will see when real roles are introduced), and because parents can have custom callbacks even when the child fulfills a standard role. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add bdrv_make_empty()Max Reitz1-0/+23
Right now, all users of bdrv_make_empty() call the BlockDriver method directly. That is not only bad style, it is also wrong, unless the caller has a BdrvChild with a WRITE or WRITE_UNCHANGED permission. (WRITE_UNCHANGED suffices, because callers generally use this function to clear a node with a backing file after a commit operation.) Introduce bdrv_make_empty() that verifies that it does. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200429141126.85159-2-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08block: Drop unused .bdrv_has_zero_init_truncateEric Blake1-21/+0
Now that there are no clients of bdrv_has_zero_init_truncate, none of the drivers need to worry about providing it. What's more, this eliminates a source of some confusion: a literal reading of the documentation as written in ceaca56f and implemented in commit 1dcaf527 claims that a driver which returns 0 for bdrv_has_zero_init_truncate() must not return 1 for bdrv_has_zero_init(); this condition was violated for parallels, qcow, and sometimes for vdi, although in practice it did not matter since those drivers also lacked .bdrv_co_truncate. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-10-eblake@redhat.com> Acked-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-04block: Avoid dead assignmentPhilippe Mathieu-Daudé1-1/+1
Fix warning reported by Clang static code analyzer: block.c:3167:5: warning: Value stored to 'ret' is never read ret = bdrv_fill_options(&options, filename, &flags, &local_err); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 462f5bcf6 Reported-by: Clang Static Analyzer Suggested-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200422133152.16770-2-philmd@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-04-30block-backend: Add flags to blk_truncate()Kevin Wolf1-1/+2
Now that node level interface bdrv_truncate() supports passing request flags to the block driver, expose this on the BlockBackend level, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30qapi: Only input visitors can actually failMarkus Armbruster1-8/+1
The previous few commits have made this more obvious, and removed the one exception. Time to clarify the documentation, and drop dead error checking. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200424084338.26803-13-armbru@redhat.com>
2020-03-27block: fix bdrv_root_attach_child forget to unref child_bsVladimir Sementsov-Ogievskiy1-0/+1
bdrv_root_attach_child promises to drop child_bs reference on failure. It does it on first handled failure path, but not on the second. Fix that. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200324155921.23822-1-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-26block: trickle down the fallback image creation function use to the block ↵Maxim Levitsky1-15/+20
drivers Instead of checking the .bdrv_co_create_opts to see if we need the fallback, just implement the .bdrv_co_create_opts in the drivers that need it. This way we don't break various places that need to know if the underlying protocol/format really supports image creation, and this way we still allow some drivers to not support image creation. Fixes: fd17146cd93d1704cd96d7c2757b325fc7aac6fd Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1816007 Note that technically this driver reverts the image creation fallback for the vxhs driver since I don't have a means to test it, and IMHO it is better to leave it not supported as it was prior to generic image creation patches. Also drop iscsi_create_opts which was left accidentally. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-3-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> [mreitz: Fixed alignment, and moved bdrv_co_create_opts_simple() and bdrv_create_opts_simple from block.h into block_int.h] Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26block: pass BlockDriver reference to the .bdrv_co_createMaxim Levitsky1-1/+2
This will allow the reuse of a single generic .bdrv_co_create implementation for several drivers. No functional changes. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-24block: bdrv_set_backing_bs: fix use-after-freeVladimir Sementsov-Ogievskiy1-1/+1
There is a use-after-free possible: bdrv_unref_child() leaves bs->backing freed but not NULL. bdrv_attach_child may produce nested polling loop due to drain, than access of freed pointer is possible. I've produced the following crash on 30 iotest with modified code. It does not reproduce on master, but still seems possible: #0 __strcmp_avx2 () at /lib64/libc.so.6 #1 bdrv_backing_overridden (bs=0x55c9d3cc2060) at block.c:6350 #2 bdrv_refresh_filename (bs=0x55c9d3cc2060) at block.c:6404 #3 bdrv_backing_attach (c=0x55c9d48e5520) at block.c:1063 #4 bdrv_replace_child_noperm (child=child@entry=0x55c9d48e5520, new_bs=new_bs@entry=0x55c9d3cc2060) at block.c:2290 #5 bdrv_replace_child (child=child@entry=0x55c9d48e5520, new_bs=new_bs@entry=0x55c9d3cc2060) at block.c:2320 #6 bdrv_root_attach_child (child_bs=child_bs@entry=0x55c9d3cc2060, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, ctx=<optimized out>, perm=<optimized out>, shared_perm=21, opaque=0x55c9d3c5a3d0, errp=0x7ffd117108e0) at block.c:2424 #7 bdrv_attach_child (parent_bs=parent_bs@entry=0x55c9d3c5a3d0, child_bs=child_bs@entry=0x55c9d3cc2060, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, errp=errp@entry=0x7ffd117108e0) at block.c:5876 #8 in bdrv_set_backing_hd (bs=bs@entry=0x55c9d3c5a3d0, backing_hd=backing_hd@entry=0x55c9d3cc2060, errp=errp@entry=0x7ffd117108e0) at block.c:2576 #9 stream_prepare (job=0x55c9d49d84a0) at block/stream.c:150 #10 job_prepare (job=0x55c9d49d84a0) at job.c:761 #11 job_txn_apply (txn=<optimized out>, fn=<optimized out>) at job.c:145 #12 job_do_finalize (job=0x55c9d49d84a0) at job.c:778 #13 job_completed_txn_success (job=0x55c9d49d84a0) at job.c:832 #14 job_completed (job=0x55c9d49d84a0) at job.c:845 #15 job_completed (job=0x55c9d49d84a0) at job.c:836 #16 job_exit (opaque=0x55c9d49d84a0) at job.c:864 #17 aio_bh_call (bh=0x55c9d471a160) at util/async.c:117 #18 aio_bh_poll (ctx=ctx@entry=0x55c9d3c46720) at util/async.c:117 #19 aio_poll (ctx=ctx@entry=0x55c9d3c46720, blocking=blocking@entry=true) at util/aio-posix.c:728 #20 bdrv_parent_drained_begin_single (poll=true, c=0x55c9d3d558f0) at block/io.c:121 #21 bdrv_parent_drained_begin_single (c=c@entry=0x55c9d3d558f0, poll=poll@entry=true) at block/io.c:114 #22 bdrv_replace_child_noperm (child=child@entry=0x55c9d3d558f0, new_bs=new_bs@entry=0x55c9d3d27300) at block.c:2258 #23 bdrv_replace_child (child=child@entry=0x55c9d3d558f0, new_bs=new_bs@entry=0x55c9d3d27300) at block.c:2320 #24 bdrv_root_attach_child (child_bs=child_bs@entry=0x55c9d3d27300, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, ctx=<optimized out>, perm=<optimized out>, shared_perm=21, opaque=0x55c9d3cc2060, errp=0x7ffd11710c60) at block.c:2424 #25 bdrv_attach_child (parent_bs=parent_bs@entry=0x55c9d3cc2060, child_bs=child_bs@entry=0x55c9d3d27300, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, errp=errp@entry=0x7ffd11710c60) at block.c:5876 #26 bdrv_set_backing_hd (bs=bs@entry=0x55c9d3cc2060, backing_hd=backing_hd@entry=0x55c9d3d27300, errp=errp@entry=0x7ffd11710c60) at block.c:2576 #27 stream_prepare (job=0x55c9d495ead0) at block/stream.c:150 ... Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200316060631.30052-2-vsementsov@virtuozzo.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-24block: Assert BlockDriver::format_name is not NULLPhilippe Mathieu-Daudé1-0/+1
bdrv_do_find_format() calls strcmp() using BlockDriver::format_name as argument, which must not be NULL. Assert this field is not null when we register a block driver in bdrv_register(). Reported-by: Mansour Ahmadi <ManSoSec@gmail.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200318222235.23856-1-philmd@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-11block.c: adding bdrv_co_delete_fileDaniel Henrique Barboza1-0/+26
Using the new 'bdrv_co_delete_file' interface, a pure co_routine function 'bdrv_co_delete_file' inside block.c can can be used in a way similar of the existing bdrv_create_file to to clean up a created file. We're creating a pure co_routine because the only caller of 'bdrv_co_delete_file' will be already in co_routine context, thus there is no need to add all the machinery to check for qemu_in_coroutine() and create a separated co_routine to do the job. Suggested-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Message-Id: <20200130213907.2830642-3-danielhb413@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11block: Fix cross-AioContext blockdev-snapshotKevin Wolf1-0/+1
external_snapshot_prepare() tries to move the overlay to the AioContext of the backing file (the snapshotted node). However, it's possible that this doesn't work, but the backing file can instead be moved to the overlay's AioContext (e.g. opening the backing chain for a mirror target). bdrv_append() already indirectly uses bdrv_attach_node(), which takes care to move nodes to make sure they use the same AioContext and which tries both directions. So the problem has a simple fix: Just delete the unnecessary extra bdrv_try_set_aio_context() call in external_snapshot_prepare() and instead assert in bdrv_append() that both nodes were indeed moved to the same AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200310113831.27293-6-kwolf@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11block: Make bdrv_get_cumulative_perm() publicKevin Wolf1-4/+2
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200310113831.27293-2-kwolf@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06block: bdrv_reopen() with backing file in different AioContextKevin Wolf1-6/+26
This patch allows bdrv_reopen() (and therefore the x-blockdev-reopen QMP command) to attach a node as the new backing file even if the node is in a different AioContext than the parent if one of both nodes can be moved to the AioContext of the other node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Message-Id: <20200306141413.30705-3-kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
generated by cgit v1.1 at 2024-08-06 13:19:02 +0000