From: Max Reitz <mreitz@redhat.com> To: qemu-block@nongnu.org Cc: Kevin Wolf <kwolf@redhat.com>, Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>, qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v6 27/42] commit: Deal with filters Date: Fri, 9 Aug 2019 18:13:52 +0200 Message-ID: <20190809161407.11920-28-mreitz@redhat.com> (raw) In-Reply-To: <20190809161407.11920-1-mreitz@redhat.com> This includes some permission limiting (for example, we only need to take the RESIZE permission if the base is smaller than the top). Signed-off-by: Max Reitz <mreitz@redhat.com> --- block/block-backend.c | 16 +++++--- block/commit.c | 96 +++++++++++++++++++++++++++++++------------ blockdev.c | 6 ++- 3 files changed, 85 insertions(+), 33 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index c13c5c83b0..0bc592d023 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -2180,11 +2180,17 @@ int blk_commit_all(void) AioContext *aio_context = blk_get_aio_context(blk); aio_context_acquire(aio_context); - if (blk_is_inserted(blk) && blk->root->bs->backing) { - int ret = bdrv_commit(blk->root->bs); - if (ret < 0) { - aio_context_release(aio_context); - return ret; + if (blk_is_inserted(blk)) { + BlockDriverState *non_filter; + + /* Legacy function, so skip implicit filters */ + non_filter = bdrv_skip_implicit_filters(blk->root->bs); + if (bdrv_filtered_cow_child(non_filter)) { + int ret = bdrv_commit(non_filter); + if (ret < 0) { + aio_context_release(aio_context); + return ret; + } } } aio_context_release(aio_context); diff --git a/block/commit.c b/block/commit.c index 5a7672c7c7..40d1c8eeac 100644 --- a/block/commit.c +++ b/block/commit.c @@ -37,6 +37,7 @@ typedef struct CommitBlockJob { BlockBackend *top; BlockBackend *base; BlockDriverState *base_bs; + BlockDriverState *above_base; BlockdevOnError on_error; bool base_read_only; bool chain_frozen; @@ -110,7 +111,7 @@ static void commit_abort(Job *job) * XXX Can (or should) we somehow keep 'consistent read' blocked even * after the failed/cancelled commit job is gone? If we already wrote * something to base, the intermediate images aren't valid any more. */ - bdrv_replace_node(s->commit_top_bs, backing_bs(s->commit_top_bs), + bdrv_replace_node(s->commit_top_bs, s->commit_top_bs->backing->bs, &error_abort); bdrv_unref(s->commit_top_bs); @@ -174,7 +175,7 @@ static int coroutine_fn commit_run(Job *job, Error **errp) break; } /* Copy if allocated above the base */ - ret = bdrv_is_allocated_above(blk_bs(s->top), blk_bs(s->base), false, + ret = bdrv_is_allocated_above(blk_bs(s->top), s->above_base, true, offset, COMMIT_BUFFER_SIZE, &n); copy = (ret == 1); trace_commit_one_iteration(s, offset, n, ret); @@ -267,15 +268,35 @@ void commit_start(const char *job_id, BlockDriverState *bs, CommitBlockJob *s; BlockDriverState *iter; BlockDriverState *commit_top_bs = NULL; + BlockDriverState *filtered_base; Error *local_err = NULL; + int64_t base_size, top_size; + uint64_t perms, iter_shared_perms; int ret; assert(top != bs); - if (top == base) { + if (bdrv_skip_rw_filters(top) == bdrv_skip_rw_filters(base)) { error_setg(errp, "Invalid files for merge: top and base are the same"); return; } + base_size = bdrv_getlength(base); + if (base_size < 0) { + error_setg_errno(errp, -base_size, "Could not inquire base image size"); + return; + } + + top_size = bdrv_getlength(top); + if (top_size < 0) { + error_setg_errno(errp, -top_size, "Could not inquire top image size"); + return; + } + + perms = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE; + if (base_size < top_size) { + perms |= BLK_PERM_RESIZE; + } + s = block_job_create(job_id, &commit_job_driver, NULL, bs, 0, BLK_PERM_ALL, speed, creation_flags, NULL, NULL, errp); if (!s) { @@ -315,17 +336,43 @@ void commit_start(const char *job_id, BlockDriverState *bs, s->commit_top_bs = commit_top_bs; - /* Block all nodes between top and base, because they will - * disappear from the chain after this operation. */ - assert(bdrv_chain_contains(top, base)); - for (iter = top; iter != base; iter = backing_bs(iter)) { - /* XXX BLK_PERM_WRITE needs to be allowed so we don't block ourselves - * at s->base (if writes are blocked for a node, they are also blocked - * for its backing file). The other options would be a second filter - * driver above s->base. */ + /* + * Block all nodes between top and base, because they will + * disappear from the chain after this operation. + * Note that this assumes that the user is fine with removing all + * nodes (including R/W filters) between top and base. Assuring + * this is the responsibility of the interface (i.e. whoever calls + * commit_start()). + */ + s->above_base = bdrv_find_overlay(top, base); + assert(s->above_base); + + /* + * The topmost node with + * bdrv_skip_rw_filters(filtered_base) == bdrv_skip_rw_filters(base) + */ + filtered_base = bdrv_filtered_cow_bs(s->above_base); + assert(bdrv_skip_rw_filters(filtered_base) == bdrv_skip_rw_filters(base)); + + /* + * XXX BLK_PERM_WRITE needs to be allowed so we don't block ourselves + * at s->base (if writes are blocked for a node, they are also blocked + * for its backing file). The other options would be a second filter + * driver above s->base. + */ + iter_shared_perms = BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE; + + for (iter = top; iter != base; iter = bdrv_filtered_bs(iter)) { + if (iter == filtered_base) { + /* + * From here on, all nodes are filters on the base. This + * allows us to share BLK_PERM_CONSISTENT_READ. + */ + iter_shared_perms |= BLK_PERM_CONSISTENT_READ; + } + ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0, - BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE, - errp); + iter_shared_perms, errp); if (ret < 0) { goto fail; } @@ -342,9 +389,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, } s->base = blk_new(s->common.job.aio_context, - BLK_PERM_CONSISTENT_READ - | BLK_PERM_WRITE - | BLK_PERM_RESIZE, + perms, BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | BLK_PERM_WRITE_UNCHANGED); @@ -412,19 +457,22 @@ int bdrv_commit(BlockDriverState *bs) if (!drv) return -ENOMEDIUM; - if (!bs->backing) { + backing_file_bs = bdrv_filtered_cow_bs(bs); + + if (!backing_file_bs) { return -ENOTSUP; } if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) || - bdrv_op_is_blocked(bs->backing->bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) { + bdrv_op_is_blocked(backing_file_bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) + { return -EBUSY; } - ro = bs->backing->bs->read_only; + ro = backing_file_bs->read_only; if (ro) { - if (bdrv_reopen_set_read_only(bs->backing->bs, false, NULL)) { + if (bdrv_reopen_set_read_only(backing_file_bs, false, NULL)) { return -EACCES; } } @@ -440,8 +488,6 @@ int bdrv_commit(BlockDriverState *bs) } /* Insert commit_top block node above backing, so we can write to it */ - backing_file_bs = backing_bs(bs); - commit_top_bs = bdrv_new_open_driver(&bdrv_commit_top, NULL, BDRV_O_RDWR, &local_err); if (commit_top_bs == NULL) { @@ -526,15 +572,13 @@ ro_cleanup: qemu_vfree(buf); blk_unref(backing); - if (backing_file_bs) { - bdrv_set_backing_hd(bs, backing_file_bs, &error_abort); - } + bdrv_set_backing_hd(bs, backing_file_bs, &error_abort); bdrv_unref(commit_top_bs); blk_unref(src); if (ro) { /* ignoring error return here */ - bdrv_reopen_set_read_only(bs->backing->bs, true, NULL); + bdrv_reopen_set_read_only(backing_file_bs, true, NULL); } return ret; diff --git a/blockdev.c b/blockdev.c index c6f79b4e0e..7bef41c0b0 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1094,7 +1094,7 @@ void hmp_commit(Monitor *mon, const QDict *qdict) return; } - bs = blk_bs(blk); + bs = bdrv_skip_implicit_filters(blk_bs(blk)); aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); @@ -3454,7 +3454,9 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, assert(bdrv_get_aio_context(base_bs) == aio_context); - for (iter = top_bs; iter != backing_bs(base_bs); iter = backing_bs(iter)) { + for (iter = top_bs; iter != bdrv_filtered_bs(base_bs); + iter = bdrv_filtered_bs(iter)) + { if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) { goto out; } -- 2.21.0
next prev parent reply index Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-09 16:13 [Qemu-devel] [PATCH v6 00/42] block: " Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 01/42] block: Mark commit and mirror as filter drivers Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 02/42] copy-on-read: Support compressed writes Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 03/42] throttle: " Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 04/42] block: Add child access functions Max Reitz 2019-08-09 16:56 ` Eric Blake 2019-09-04 16:16 ` Kevin Wolf 2019-09-09 7:56 ` Max Reitz 2019-09-09 9:36 ` Kevin Wolf 2019-09-09 14:04 ` Max Reitz 2019-09-09 16:13 ` Kevin Wolf 2019-09-10 9:14 ` Max Reitz 2019-09-10 10:47 ` Kevin Wolf 2019-09-10 11:36 ` Max Reitz 2019-09-10 12:48 ` Kevin Wolf 2019-09-10 12:59 ` Max Reitz 2019-09-10 13:10 ` Kevin Wolf 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 05/42] block: Add chain helper functions Max Reitz 2019-08-09 17:01 ` Eric Blake 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 06/42] qcow2: Implement .bdrv_storage_child() Max Reitz 2019-08-09 17:07 ` Eric Blake 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 07/42] block: *filtered_cow_child() for *has_zero_init() Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 08/42] block: bdrv_set_backing_hd() is about bs->backing Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 09/42] block: Include filters when freezing backing chain Max Reitz 2019-08-10 13:32 ` Vladimir Sementsov-Ogievskiy 2019-08-12 12:56 ` Max Reitz 2019-09-05 13:05 ` Kevin Wolf 2019-09-09 8:02 ` Max Reitz 2019-09-09 9:40 ` Kevin Wolf 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 10/42] block: Drop bdrv_is_encrypted() Max Reitz 2019-08-10 13:42 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 11/42] block: Add bdrv_supports_compressed_writes() Max Reitz 2019-09-05 13:11 ` Kevin Wolf 2019-09-09 8:09 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 12/42] block: Use bdrv_filtered_rw* where obvious Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 13/42] block: Use CAFs in block status functions Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 14/42] block: Use CAFs when working with backing chains Max Reitz 2019-08-10 15:19 ` Vladimir Sementsov-Ogievskiy 2019-09-05 14:05 ` Kevin Wolf 2019-09-09 8:25 ` Max Reitz 2019-09-09 9:55 ` Kevin Wolf 2019-09-09 14:08 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 15/42] block: Re-evaluate backing file handling in reopen Max Reitz 2019-08-10 16:05 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 16/42] block: Flush all children in generic code Max Reitz 2019-08-10 15:36 ` Vladimir Sementsov-Ogievskiy 2019-08-12 12:58 ` Max Reitz 2019-09-05 16:24 ` Kevin Wolf 2019-09-09 8:31 ` Max Reitz 2019-09-09 10:01 ` Kevin Wolf 2019-09-09 14:15 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 17/42] block: Use CAFs in bdrv_refresh_limits() Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 18/42] block: Use CAFs in bdrv_refresh_filename() Max Reitz 2019-08-10 16:22 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 19/42] block: Use CAF in bdrv_co_rw_vmstate() Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 20/42] block/snapshot: Fix fallback Max Reitz 2019-08-10 16:34 ` Vladimir Sementsov-Ogievskiy 2019-08-12 13:06 ` Max Reitz 2019-09-10 11:56 ` Kevin Wolf 2019-09-10 12:04 ` Max Reitz 2019-09-10 12:49 ` Kevin Wolf 2019-09-10 13:06 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 21/42] block: Use CAFs for debug breakpoints Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 22/42] block: Fix bdrv_get_allocated_file_size's fallback Max Reitz 2019-08-10 16:41 ` Vladimir Sementsov-Ogievskiy 2019-08-12 13:09 ` Max Reitz 2019-08-12 17:14 ` Vladimir Sementsov-Ogievskiy 2019-08-12 19:15 ` Max Reitz 2019-09-10 14:52 ` Kevin Wolf 2019-09-11 6:20 ` Max Reitz 2019-09-11 6:55 ` Kevin Wolf 2019-09-11 7:37 ` Max Reitz 2019-09-11 8:27 ` Kevin Wolf 2019-09-11 10:00 ` Max Reitz 2019-09-11 10:31 ` Kevin Wolf 2019-09-11 11:00 ` Max Reitz 2019-09-12 10:34 ` Kevin Wolf 2019-11-14 13:11 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 23/42] blockdev: Use CAF in external_snapshot_prepare() Max Reitz 2019-09-10 15:02 ` Kevin Wolf 2019-09-11 6:21 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 24/42] block: Use child access functions for QAPI queries Max Reitz 2019-08-10 16:57 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 25/42] mirror: Deal with filters Max Reitz 2019-08-12 11:09 ` Vladimir Sementsov-Ogievskiy 2019-08-12 13:26 ` Max Reitz 2019-08-14 15:17 ` Vladimir Sementsov-Ogievskiy 2019-08-31 9:57 ` Vladimir Sementsov-Ogievskiy 2019-09-02 14:35 ` Max Reitz 2019-09-03 8:32 ` Vladimir Sementsov-Ogievskiy 2019-09-09 7:41 ` Max Reitz 2019-09-13 12:55 ` Kevin Wolf 2019-09-16 10:26 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 26/42] backup: " Max Reitz 2019-08-09 16:13 ` Max Reitz [this message] 2019-08-31 10:44 ` [Qemu-devel] [PATCH v6 27/42] commit: " Vladimir Sementsov-Ogievskiy 2019-09-02 14:55 ` Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 28/42] stream: " Max Reitz 2019-08-12 11:55 ` Vladimir Sementsov-Ogievskiy 2019-09-13 14:16 ` Kevin Wolf 2019-09-16 9:52 ` Max Reitz 2019-09-16 14:47 ` Kevin Wolf 2019-12-11 12:52 ` Max Reitz 2019-12-11 15:52 ` Kevin Wolf 2019-12-11 16:12 ` Max Reitz 2019-12-11 16:35 ` Kevin Wolf 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 29/42] nbd: Use CAF when looking for dirty bitmap Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 30/42] qemu-img: Use child access functions Max Reitz 2019-08-12 12:14 ` Vladimir Sementsov-Ogievskiy 2019-08-12 13:28 ` Max Reitz 2019-08-14 16:04 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 31/42] block: Drop backing_bs() Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 32/42] block: Make bdrv_get_cumulative_perm() public Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 33/42] blockdev: Fix active commit choice Max Reitz 2019-08-09 16:13 ` [Qemu-devel] [PATCH v6 34/42] block: Inline bdrv_co_block_status_from_*() Max Reitz 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 35/42] block: Fix check_to_replace_node() Max Reitz 2019-08-15 15:21 ` Vladimir Sementsov-Ogievskiy 2019-08-15 17:01 ` Max Reitz 2019-08-16 11:01 ` Vladimir Sementsov-Ogievskiy 2019-08-16 13:30 ` Max Reitz 2019-08-16 14:24 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 36/42] iotests: Add tests for mirror @replaces loops Max Reitz 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 37/42] block: Leave BDS.backing_file constant Max Reitz 2019-08-16 16:16 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 38/42] iotests: Let complete_and_wait() work with commit Max Reitz 2019-08-23 5:59 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 39/42] iotests: Add filter commit test cases Max Reitz 2019-08-31 11:41 ` Vladimir Sementsov-Ogievskiy 2019-09-02 15:06 ` Max Reitz 2019-08-31 12:35 ` Vladimir Sementsov-Ogievskiy 2019-09-02 15:09 ` Max Reitz 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 40/42] iotests: Add filter mirror " Max Reitz 2019-08-31 12:35 ` Vladimir Sementsov-Ogievskiy 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 41/42] iotests: Add test for commit in sub directory Max Reitz 2019-08-09 16:14 ` [Qemu-devel] [PATCH v6 42/42] iotests: Test committing to overridden backing Max Reitz 2019-09-03 9:18 ` Vladimir Sementsov-Ogievskiy
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190809161407.11920-28-mreitz@redhat.com \ --to=mreitz@redhat.com \ --cc=kwolf@redhat.com \ --cc=qemu-block@nongnu.org \ --cc=qemu-devel@nongnu.org \ --cc=vsementsov@virtuozzo.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
QEMU-Devel Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/qemu-devel/0 qemu-devel/git/0.git git clone --mirror https://lore.kernel.org/qemu-devel/1 qemu-devel/git/1.git git clone --mirror https://lore.kernel.org/qemu-devel/2 qemu-devel/git/2.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 qemu-devel qemu-devel/ https://lore.kernel.org/qemu-devel \ qemu-devel@nongnu.org public-inbox-index qemu-devel Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.nongnu.qemu-devel AGPL code for this site: git clone https://public-inbox.org/public-inbox.git