From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3BABFD43; Thu, 23 Nov 2023 04:52:04 -0800 (PST) Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4SbdKp5DtBz4f3jYW; Thu, 23 Nov 2023 20:51:58 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 6C0F21A0221; Thu, 23 Nov 2023 20:52:00 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP1 (Coremail) with SMTP id cCh0CgDn6xHdSl9lSfnfBg--.20473S7; Thu, 23 Nov 2023 20:52:00 +0800 (CST) From: Zhang Yi To: linux-ext4@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, ritesh.list@gmail.com, hch@infradead.org, djwong@kernel.org, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, chengzhihao1@huawei.com, yukuai3@huawei.com Subject: [RFC PATCH 03/18] ext4: correct the hole length returned by ext4_map_blocks() Date: Thu, 23 Nov 2023 20:51:05 +0800 Message-Id: <20231123125121.4064694-4-yi.zhang@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231123125121.4064694-1-yi.zhang@huaweicloud.com> References: <20231123125121.4064694-1-yi.zhang@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:cCh0CgDn6xHdSl9lSfnfBg--.20473S7 X-Coremail-Antispam: 1UD129KBjvJXoW7KF17Xw4fCr47trWDJrW3Awb_yoW8Kw1fpr ZxAF1fGw48Ww129F4fJF4UWF13K3W8tay7JrWfJr1rCay5C3WSgF1UAF1IyFZYgrW8XF1Y qF4UtryUCw4ay3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBE14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JrWl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMI IF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUd8n5UUUUU = X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ From: Zhang Yi In ext4_map_blocks(), if we can't find a range of mapping in the extents cache, we are calling ext4_ext_map_blocks() to search the real path. But if the querying range was tail overlaped by a delayed extent, we can't find it on the real extent path, so the returned hole length could be larger than it really is. | querying map | v v |----------{-------------}{------|----------------}-----... ^ ^ ^^ ^ | uncached | hole extent || delayed extent | We have to adjust the mapping length to the next not hole extent's lblk before searching the extent path. Signed-off-by: Zhang Yi --- fs/ext4/inode.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 4ce35f1c8b0a..94e7b8500878 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -479,6 +479,7 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags) { struct extent_status es; + ext4_lblk_t next; int retval; int ret = 0; #ifdef ES_AGGRESSIVE_TEST @@ -502,8 +503,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, return -EFSCORRUPTED; /* Lookup extent status tree firstly */ - if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) && - ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) { + if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) + goto uncached; + + if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) { if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) { map->m_pblk = ext4_es_pblock(&es) + map->m_lblk - es.es_lblk; @@ -532,6 +535,23 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, #endif goto found; } + /* + * Not found, maybe a hole, need to adjust the map length before + * seraching the real extent path. It can prevent incorrect hole + * length returned if the following entries have delayed only + * ones. + */ + if (!(flags & EXT4_GET_BLOCKS_CREATE) && es.es_lblk > map->m_lblk) { + next = es.es_lblk; + if (ext4_es_is_hole(&es)) + next = ext4_es_skip_hole_extent(inode, map->m_lblk, + map->m_len); + retval = next - map->m_lblk; + if (map->m_len > retval) + map->m_len = retval; + } + +uncached: /* * In the query cache no-wait mode, nothing we can do more if we * cannot find extent in the cache. -- 2.39.2