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Tue, 04 Aug 2020 12:46:45 +0200 Date: Tue, 4 Aug 2020 12:46:42 +0200 From: Lukas Straub To: qemu-devel Subject: [PATCH v3 1/7] block/quorum.c: stable children names Message-ID: <5d5f930424c1c770754041aa8ad6421dc4e2b58e.1596536719.git.lukasstraub2@web.de> In-Reply-To: References: MIME-Version: 1.0 X-Provags-ID: V03:K1:ZUIWubNMRMn3fQD4t3xE6/tLITlKvRmaOvCQQXcjzL/dxBzdaO5 /EkrjbrX6o72wT0bChtH8UVyztSPyxwzI7PLpxqZ++o7Y7Q+fZq4IyATqjxNCZTUQrHDH6s NInDEEm9QY50PBRP7UAfCCpxyTAp/94i1+cQMdkQYq6uj4hqS+qkQ4FEBKMy3sz4l9H8a/T JspvVCppH2EDVxhNbnU1g== X-UI-Out-Filterresults: notjunk:1;V03:K0:dibcz/EU/NU=:MCNU3EN/nqqeHasMecoFFL uU0BJHXZ+rk+uoLfbqGRCkdri3r52S2x7ajupLWnSm3InsDGdFR+iGM9i32eeeaudBk9MEEDM EXkOeHoe4U5/IH6anLm5g4l/0NgxSEDIrXiULBBJHMT49ys1GL2OYSGX/zh9z9NYlVWc8VdbH tDnL9+t5zh1QpbDFOBgKVWzzzV22r6h9SQzOGbzrbTwjDNyksZ9MC54EptZ/GMA0VH02wxgLy /RrSHzLgqvM3+amD/du93qKBa7xNeOkVJG+8BljdlIw518RtD+jm7UMwrZREcXIHwNRieqoAi 8uQ+bK9V7HBxOnV+AwLdgVFlbc6odoY0iVcHx2J5o59NXEy6pbamfWI4Ty2fmq2uWp9bcAYdQ aEuRMVxzcC0Rc1IIAEiRZIsPtV8W+Jizzz7zxsh1u23is73AfjNU3QkiL9HBC9J8ZjgfWW088 0Wx5zLE2AnzQMAKvNCYdiWov04zmMHMLNsr7mrZjlpQWCRNJXrRnDVU3Bz0NxcC8K6htzdZqg +AHJ0fjW7tM425UqhCYXnuvY/JtNdS+mGmZ4ki3ieCYBzYXhb0c824mHS1MK7XDt6BO+93B0x Lx2bD8rBY2q15gYIomS9G6fPqrthg2DEhfMaJo1azi6XiTVoF9w46g1djcc7Pb6cqUSm/wTGC C8Fbhc9u0qajZhUZCLc1wbRLqNSsuo4NSaf8w4MO0pFubGDXS8csjOhd16xfv5Ca6M9s4yPCg 3gaFnfHNqPuMtxzFub4zVcTbahbTqv4QbJdkZ6tuYJUYzTbA9+7Re+8f+CRnjZSDT5EFgFaDo k38+ibFiZd/N7cRFsDHRbmm9FerOl1yEWQLg5+hzVlOWQiZ00Dn/wGOCTf7CMYo9mB1Cmd5qV RZt9JLHw9NkjLzF4mq7sUS1UI/tPWUjEMBZ+vUUZ+1WC8Sk7HvJIQcIiB5BTm+5GgC3b3h4u/ ai65BLY3CIKVnvoOK/yWXgSiUkBl4H4g3fW+hcbcO9DkE5pS3Xif5qZKzQM469G7t2gQ8aKSa Lr1QAQKMzU25+VlGE/ZhRmdojfhkGP9eJqYVRGa4sigCTSJsGVYMt7k+86b3EgCWoUbfwRS7z mkgDmF3HOMiLzvAnAlEYQpNhBKltztlBOM8hgY0myqjTdnqFzVBqfJR1mnL6uIelH38uY86UM 88xz9QrvZctdu5qZQnoyGpYcQMdHV0Eu4cZeO5Cic+3ydmc51ZDRjDCi1wRsEe1reWqhM1fCF 1VUjGNEYvMc2UMIkpF0U3wiNKdhEv5oHBLKwQ6A== Received-SPF: pass client-ip=212.227.15.3; envelope-from=lukasstraub2@web.de; helo=mout.web.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/04 06:47:13 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Alberto Garcia , "Dr. David Alan Gilbert" , Wainer dos Santos Moschetta , Max Reitz , Zhang Chen , Cleber Rosa , Philippe =?utf-8?q?Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" If we remove the child with the highest index from the quorum, decrement s->next_child_index. This way we get stable children names as long as we only remove the last child. Signed-off-by: Lukas Straub Fixes: https://bugs.launchpad.net/bugs/1881231 Reviewed-by: Zhang Chen Reviewed-by: Alberto Garcia --- block/quorum.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) -- 2.20.1 diff --git a/block/quorum.c b/block/quorum.c index 6df9449fc2..e846a7e892 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -29,6 +29,8 @@ #define HASH_LENGTH 32 +#define INDEXSTR_LEN 32 + #define QUORUM_OPT_VOTE_THRESHOLD "vote-threshold" #define QUORUM_OPT_BLKVERIFY "blkverify" #define QUORUM_OPT_REWRITE "rewrite-corrupted" @@ -970,9 +972,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, opened = g_new0(bool, s->num_children); for (i = 0; i < s->num_children; i++) { - char indexstr[32]; - ret = snprintf(indexstr, 32, "children.%d", i); - assert(ret < 32); + char indexstr[INDEXSTR_LEN]; + ret = snprintf(indexstr, INDEXSTR_LEN, "children.%d", i); + assert(ret < INDEXSTR_LEN); s->children[i] = bdrv_open_child(NULL, options, indexstr, bs, &child_of_bds, BDRV_CHILD_DATA, false, @@ -1024,7 +1026,7 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, { BDRVQuorumState *s = bs->opaque; BdrvChild *child; - char indexstr[32]; + char indexstr[INDEXSTR_LEN]; int ret; if (s->is_blkverify) { @@ -1039,8 +1041,8 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, return; } - ret = snprintf(indexstr, 32, "children.%u", s->next_child_index); - if (ret < 0 || ret >= 32) { + ret = snprintf(indexstr, INDEXSTR_LEN, "children.%u", s->next_child_index); + if (ret < 0 || ret >= INDEXSTR_LEN) { error_setg(errp, "cannot generate child name"); return; } @@ -1068,6 +1070,7 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child, Error **errp) { BDRVQuorumState *s = bs->opaque; + char indexstr[INDEXSTR_LEN]; int i; for (i = 0; i < s->num_children; i++) { @@ -1089,6 +1092,11 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child, /* We know now that num_children > threshold, so blkverify must be false */ assert(!s->is_blkverify); + snprintf(indexstr, INDEXSTR_LEN, "children.%u", s->next_child_index - 1); + if (!strncmp(child->name, indexstr, INDEXSTR_LEN)) { + s->next_child_index--; + } + bdrv_drained_begin(bs); /* We can safely remove this child now */