From nobody Fri Dec 19 22:04:12 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E238E295D89 for ; Thu, 15 May 2025 06:53:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292036; cv=none; b=u68NfP9yFEh44jkVk1Xtboh3a6DouX6j86THO2ubXNbmktH+syGjSCoCiAa1CQK2yiadM34VROAonPYi1Fvod7TMQeY9GW5heqEU56mELel3tTaiGVERATU2MB3X/2RFwhezViEzA7q8PiUc+hq4zDRWGhb7RY1y/RM3+zK4w44= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292036; c=relaxed/simple; bh=cktv4CITdACV+eHzgXvFw72qwUohYgukS+pZ/hDTUdc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=N29XIuVx4F+jaks/nxr4m/r+Ti8gjfZtaiy5XlE9R1pMYjMzUPSH52Tn8K5sIFjhN2cX2FY2VRGcUteocDvGUP4L/zmU4JlJHzZl6hooLwwoEv0Tq4QG2YWlnecoY6hoHcztWlPJbBiuhCKJrUfYhwBiYso931H0sCjbzzuLCr8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4ZygsL1ZDXz4f3jtT for ; Thu, 15 May 2025 14:53:26 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id CC7BA1A07BD for ; Thu, 15 May 2025 14:53:45 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.101.6]) by APP4 (Coremail) with SMTP id gCh0CgAHbGB3jyVoyDnbMQ--.29023S3; Thu, 15 May 2025 14:53:45 +0800 (CST) From: Kemeng Shi To: hughd@google.com, baolin.wang@linux.alibaba.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/5] mm: shmem: avoid unpaired folio_unlock() in shmem_swapin_folio() Date: Thu, 15 May 2025 23:47:54 +0800 Message-Id: <20250515154758.956521-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20250515154758.956521-1-shikemeng@huaweicloud.com> References: <20250515154758.956521-1-shikemeng@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAHbGB3jyVoyDnbMQ--.29023S3 X-Coremail-Antispam: 1UD129KBjvdXoWrZw15CF17tw4xWw13tF47Arb_yoWfZFgEvF 1kt34UWw4Igwn29r1jkFW3X34F93yFvwn8uFyxKFy3A3s8tr4kZFWktr1Yqr9rWFy29rsI kF1qqrZIvry2gjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbDAYFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l87I20VAvwVAaII0Ic2I_JFv_Gryl82 xGYIkIc2x26280x7IE14v26r18M28IrcIa0xkI8VCY1x0267AKxVWUXVWUCwA2ocxC64kI II0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7 xvwVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2 z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4 xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v2 6r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCY1x0262kKe7AKxV WUAVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r 4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07j3ManU UUUU= X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ Content-Type: text/plain; charset="utf-8" If we get a folio from swap_cache_get_folio() successfully but encounter a failure before the folio is locked, we will unlock the folio which was not previously locked. Put the folio and set it to NULL when a failure occurs before the folio is locked to fix the issue. Fixes: 058313515d5aa ("mm: shmem: fix potential data corruption during shme= m swapin") Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang Reviewed-by: Kairui Song --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index 99327c30507c..980fa15f393e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2335,6 +2335,8 @@ static int shmem_swapin_folio(struct inode *inode, pg= off_t index, */ split_order =3D shmem_split_large_entry(inode, index, swap, gfp); if (split_order < 0) { + folio_put(folio); + folio =3D NULL; error =3D split_order; goto failed; } --=20 2.30.0 From nobody Fri Dec 19 22:04:12 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E2454296FAA for ; Thu, 15 May 2025 06:53:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292037; cv=none; b=XQ7yznpP7FnnfL9/T8uVViqelpu+xu5m1wAGrn8neWYmu9BMAjX8EpMjbudmLXR8uNVK+zw1malOtPzNRGL8/XouuLA1m7toAsdfu3NCg7VtJxUoM1+TwH00wwwUnumjeGRpvE8BcoSF0m7tkvFhK9BiPh9JWpGn0+pSPYPO/Vk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292037; c=relaxed/simple; bh=u7TQLclURhqvIONaGUJ90uZf4sRaHuwSF46nl8kNkng=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=mkDP3RkfIzvAx3MOroD3OIOaA6ckHnGuMaKRoIRgESOvOvpmKm3GWtp9VaVYlOqwgifdifUIQJt1kayKtNTsnxgvE5SLZB6h9AjBI3929IPYnGMRshQfoJXhHhy6J4lYe0b8GcP089JqAsdJokYBI4et77lESsxlut1tC41Jjrk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4ZygsC67Lxz4f3kvp for ; Thu, 15 May 2025 14:53:19 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 267711A0B52 for ; Thu, 15 May 2025 14:53:46 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.101.6]) by APP4 (Coremail) with SMTP id gCh0CgAHbGB3jyVoyDnbMQ--.29023S4; Thu, 15 May 2025 14:53:45 +0800 (CST) From: Kemeng Shi To: hughd@google.com, baolin.wang@linux.alibaba.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/5] mm: shmem: add missing shmem_unacct_size() in __shmem_file_setup() Date: Thu, 15 May 2025 23:47:55 +0800 Message-Id: <20250515154758.956521-3-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20250515154758.956521-1-shikemeng@huaweicloud.com> References: <20250515154758.956521-1-shikemeng@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAHbGB3jyVoyDnbMQ--.29023S4 X-Coremail-Antispam: 1UD129KBjvdXoW7GrW3JrWDtw4rZF4xAr1UKFg_yoWDZrcEk3 y8Jr4rGFsxXrnxXF4jka92gryfXFWqyFZxWryfK343ZF1DtrykGFZ5ZrZIgry7Z3WFqas8 Aw18ZrsIgF429jkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbDAYFVCjjxCrM7AC8VAFwI0_Xr0_Wr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l87I20VAvwVAaII0Ic2I_JFv_Gryl82 xGYIkIc2x26280x7IE14v26r15M28IrcIa0xkI8VCY1x0267AKxVWUCVW8JwA2ocxC64kI II0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7 xvwVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2 z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4 xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v2 6r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCY1x0262kKe7AKxV WUAVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r 4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jhxhLU UUUU= X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ Content-Type: text/plain; charset="utf-8" We will miss shmem_unacct_size() when is_idmapped_mnt() returns a failure. Move is_idmapped_mnt() before shmem_acct_size() to fix the issue. Fixes: 7a80e5b8c6fa7 ("shmem: support idmapped mounts for tmpfs") Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang --- mm/shmem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 980fa15f393e..495e661eb8bb 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5812,12 +5812,12 @@ static struct file *__shmem_file_setup(struct vfsmo= unt *mnt, const char *name, if (size < 0 || size > MAX_LFS_FILESIZE) return ERR_PTR(-EINVAL); =20 - if (shmem_acct_size(flags, size)) - return ERR_PTR(-ENOMEM); - if (is_idmapped_mnt(mnt)) return ERR_PTR(-EINVAL); =20 + if (shmem_acct_size(flags, size)) + return ERR_PTR(-ENOMEM); + inode =3D shmem_get_inode(&nop_mnt_idmap, mnt->mnt_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags); if (IS_ERR(inode)) { --=20 2.30.0 From nobody Fri Dec 19 22:04:12 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E231D1C27 for ; 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dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4ZygsL60Z2z4f3k5c for ; Thu, 15 May 2025 14:53:26 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 70CAD1A14F3 for ; Thu, 15 May 2025 14:53:46 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.101.6]) by APP4 (Coremail) with SMTP id gCh0CgAHbGB3jyVoyDnbMQ--.29023S5; Thu, 15 May 2025 14:53:46 +0800 (CST) From: Kemeng Shi To: hughd@google.com, baolin.wang@linux.alibaba.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/5] mm/shmem: Fix potential dead loop in shmem_unuse() Date: Thu, 15 May 2025 23:47:56 +0800 Message-Id: <20250515154758.956521-4-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20250515154758.956521-1-shikemeng@huaweicloud.com> References: <20250515154758.956521-1-shikemeng@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAHbGB3jyVoyDnbMQ--.29023S5 X-Coremail-Antispam: 1UD129KBjvJXoW7ZFWfWrWDtw45Ar4xGr43trb_yoW8Zr1Upr n8u3srtrWrZrykGFWIy3W8urWaqw4SgF4Utay3C3Z5A3WUtr42grnFqFyUu393CrZxXrW3 KFn29ry3Aa1vyrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPFb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M2 8IrcIa0xkI8VA2jI8067AKxVWUWwA2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK 0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4 x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l 84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I 8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AK xVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lc7CjxVAaw2AFwI 0_JF0_Jw1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG 67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMI IYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E 14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUaTKu UUUUU X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ Content-Type: text/plain; charset="utf-8" If multi shmem_unuse() for different swap type is called concurrently, a dead loop could occur as following: shmem_unuse(typeA) shmem_unuse(typeB) mutex_lock(&shmem_swaplist_mutex) list_for_each_entry_safe(info, next, ...) ... mutex_unlock(&shmem_swaplist_mutex) /* info->swapped may drop to 0 */ shmem_unuse_inode(&info->vfs_inode, type) mutex_lock(&shmem_swaplist_mutex) list_for_each_entry(info, next, ...) if (!info->swapped) list_del_init(&info->swaplist) ... mutex_unlock(&shmem_swaplist_mutex) mutex_lock(&shmem_swaplist_mutex) /* iterate with offlist entry and encounter a dead loop */ next =3D list_next_entry(info, swaplist); ... Restart the iteration if the inode is already off shmem_swaplist list to fix the issue. Fixes: b56a2d8af9147 ("mm: rid swapoff of quadratic complexity") Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang --- mm/shmem.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 495e661eb8bb..aeeddf612baa 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1505,6 +1505,7 @@ int shmem_unuse(unsigned int type) return 0; =20 mutex_lock(&shmem_swaplist_mutex); +start_over: list_for_each_entry_safe(info, next, &shmem_swaplist, swaplist) { if (!info->swapped) { list_del_init(&info->swaplist); @@ -1523,13 +1524,15 @@ int shmem_unuse(unsigned int type) cond_resched(); =20 mutex_lock(&shmem_swaplist_mutex); - next =3D list_next_entry(info, swaplist); - if (!info->swapped) - list_del_init(&info->swaplist); if (atomic_dec_and_test(&info->stop_eviction)) wake_up_var(&info->stop_eviction); if (error) break; + if (list_empty(&info->swaplist)) + goto start_over; + next =3D list_next_entry(info, swaplist); + if (!info->swapped) + list_del_init(&info->swaplist); } mutex_unlock(&shmem_swaplist_mutex); =20 --=20 2.30.0 From nobody Fri Dec 19 22:04:12 2025 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 53B10297129 for ; Thu, 15 May 2025 06:53:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292039; cv=none; b=DhZafiaDozzdZuo6JfGzuQQIVTzwEg8Omdg1bkhQKr4Nd1WmdX/Jek7l8CMSW4zS81B4HMNx4KwJ4hrw9kp20CskayMmGwKS2YYbTtHioomxfsS1Y6+7Sx/r4Sh29CCUKlouX+Q6w923EFvzdq6w4tNhDMBsU5SuY3Tol9xowFM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292039; c=relaxed/simple; bh=IvviUiMfFa2Il5r7kiUngPBt19pjIZJAasz6QAnn2r4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=mDtdFnPlf/sBz3LGSIiaOzQXOznG0sJIyuF6BDIg2/BeMAJVursfyqu73EI6I9HAaR2lM68GoL19hxAl1gHipph8KFI82NEsApdC+xFH+FUHIjT0tT83UUJS2EtMunFRbrKeQLr2NKVYbk3pjuPx4J77pHd6lEsUXHZER4VN2yg= ARC-Authentication-Results: i=1; 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charset="utf-8" Even if we fail to allocate a swap entry, the inode might have previously allocated entry and we might take inode containing swap entry off swaplist. As a result, try_to_unuse() may enter a potential dead loop to repeatedly look for inode and clean it's swap entry. Only take inode off swaplist when it's swapped page count is 0 to fix the issue. Fixes: b487a2da3575b ("mm, swap: simplify folio swap allocation") Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang Reviewed-by: Kairui Song --- mm/shmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index aeeddf612baa..07b8e1400c67 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1651,8 +1651,8 @@ static int shmem_writepage(struct page *page, struct = writeback_control *wbc) BUG_ON(folio_mapped(folio)); return swap_writepage(&folio->page, wbc); } - - list_del_init(&info->swaplist); + if (!info->swapped) + list_del_init(&info->swaplist); mutex_unlock(&shmem_swaplist_mutex); if (nr_pages > 1) goto try_split; --=20 2.30.0 From nobody Fri Dec 19 22:04:12 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 046BF296FB2 for ; Thu, 15 May 2025 06:53:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292037; cv=none; b=fdHtcl4I2+cYr1KxLDJW6w04YyQ/iNnY/WLwgyHYjZXfopc+vW4eq9QsQsG0307wpWedQrvQjLAG9nkUrd5vJbZCF0kesnnepPQIJnWeNnNFwoJi2m8J2KA12Oti6kVrm7lzwAf5d9YzZ4k2Vw4Eu8482ZGGWcEVHy8GayzIoHc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747292037; c=relaxed/simple; bh=DGgY3PsCEFXbz5sTap0X8MmZmUtGg6pc/mORDbTSaQk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JFxoKnu/ukbmksO2J1IsJ9OKZ28x3DJJJIqonlt8Yyy44VN6iVs9azgNBy8lRMIESxob/XljuPMT2Cv95McT43bbiHZPWTMvTy8May6yx3X6LeKmTufRIdzP1rI1HuMzdrH1M3b0MFi7Pb/zRdHNvDHU9QNBbcvAuhfUG4HhhEI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4ZygsM3M3qz4f3jYl for ; Thu, 15 May 2025 14:53:27 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 161B21A0359 for ; Thu, 15 May 2025 14:53:47 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.101.6]) by APP4 (Coremail) with SMTP id gCh0CgAHbGB3jyVoyDnbMQ--.29023S7; Thu, 15 May 2025 14:53:46 +0800 (CST) From: Kemeng Shi To: hughd@google.com, baolin.wang@linux.alibaba.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 5/5] mm/shmem: remove unneeded xa_is_value() check in shmem_unuse_swap_entries() Date: Thu, 15 May 2025 23:47:58 +0800 Message-Id: <20250515154758.956521-6-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20250515154758.956521-1-shikemeng@huaweicloud.com> References: <20250515154758.956521-1-shikemeng@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAHbGB3jyVoyDnbMQ--.29023S7 X-Coremail-Antispam: 1UD129KBjvdXoW7XrWkWrWDtF1kCF18AF1UJrb_yoW3urc_uF y8t3WkWrWrZr4xWFnIkFWfWFZYg39Y9rWDZa10yFyayryDtFs5G3ykJrsxAry7uF4qqFs0 yF1xZrsIkrnrWjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbqkYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l87I20VAvwVAaII0Ic2I_JFv_Gryl82 xGYIkIc2x26280x7IE14v26r126s0DM28IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC 64kIII0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM2 8EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq 3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8w Aqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE 14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCY1x0262kKe7 AKxVWUAVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02 F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw 1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r 1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07ja g4hUUUUU= X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ Content-Type: text/plain; charset="utf-8" As only value entry will be added to fbatch in shmem_find_swap_entries(), there is no need to do xa_is_value() check in shmem_unuse_swap_entries(). Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang --- mm/shmem.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 07b8e1400c67..4b42419ce6b2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1446,8 +1446,6 @@ static int shmem_unuse_swap_entries(struct inode *ino= de, for (i =3D 0; i < folio_batch_count(fbatch); i++) { struct folio *folio =3D fbatch->folios[i]; =20 - if (!xa_is_value(folio)) - continue; error =3D shmem_swapin_folio(inode, indices[i], &folio, SGP_CACHE, mapping_gfp_mask(mapping), NULL, NULL); if (error =3D=3D 0) { --=20 2.30.0