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Mon, 16 Aug 2021 01:36:28 -0400 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DC56C061764 for ; Sun, 15 Aug 2021 22:35:57 -0700 (PDT) Received: by mail-ej1-x633.google.com with SMTP id lo4so29525074ejb.7 for ; Sun, 15 Aug 2021 22:35:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BkMzMi5SrHweNSLPy5u1W+MwnSKVZJ9kZs1cY/FIIcs=; b=zoxef1iSDX5I1qIB3TJvvApvfLkcfF7Wi+ffNHFZoUv2cHhHVmX9oROTtxCVkYMHUa kL/+XF5XXZrDjBKp035iK4n3iRLxMfAM4/mZGXTRjPOVugwGGK4KYKxCi516Sx5UC4zn O7Qb6n5wTpUM0RX839n1fpzk57BJOYx8nkCx4DJEicp5gl4eDnm9czIpDc3N2DJmm3gq GHCf8l35GaonL2/6rociMX//AbRqhpCEJppZE9wQ1J6Jh4O0XFWDmIkNbelyiH+pbIY6 sFQM2wq0R2oIM5wMnj3mnJyCgVkwv78osCbrKK5XRxR0C1QBZSVAPwN8nWj/1W5pEta2 9wNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; 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charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Aug 16, 2021 at 10:35 AM Peng Tao wrote: > > On Fri, Aug 13, 2021 at 5:57 PM Xie Yongji wrote: > > > > The invalidate_inode_pages2() might be called with FUSE_NOWRITE > > set in fuse_finish_open(), which can lead to deadlock in > > fuse_launder_page(). > > > > To fix it, this tries to delay calling invalidate_inode_pages2() > > until FUSE_NOWRITE is removed. > > > > Fixes: e4648309b85a ("fuse: truncate pending writes on O_TRUNC") > > Signed-off-by: Xie Yongji > > --- > > fs/fuse/dir.c | 2 +- > > fs/fuse/file.c | 19 +++++++++++++++---- > > fs/fuse/fuse_i.h | 2 +- > > 3 files changed, 17 insertions(+), 6 deletions(-) > > > > diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c > > index eade6f965b2e..d919c3e89cb0 100644 > > --- a/fs/fuse/dir.c > > +++ b/fs/fuse/dir.c > > @@ -548,7 +548,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, > > fuse_sync_release(fi, ff, flags); > > } else { > > file->private_data = ff; > > - fuse_finish_open(inode, file); > > + fuse_finish_open(inode, file, false); > > } > > return err; > > > > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > > index 97f860cfc195..035af9c88eaf 100644 > > --- a/fs/fuse/file.c > > +++ b/fs/fuse/file.c > > @@ -193,12 +193,12 @@ static void fuse_link_write_file(struct file *file) > > spin_unlock(&fi->lock); > > } > > > > -void fuse_finish_open(struct inode *inode, struct file *file) > > +void fuse_finish_open(struct inode *inode, struct file *file, bool no_write) > > { > > struct fuse_file *ff = file->private_data; > > struct fuse_conn *fc = get_fuse_conn(inode); > > > > - if (!(ff->open_flags & FOPEN_KEEP_CACHE)) > > + if (!(ff->open_flags & FOPEN_KEEP_CACHE) && !no_write) > > invalidate_inode_pages2(inode->i_mapping); > It would break !FOPEN_KEEP_CACHE semantics, right? Fuse server asks > the kernel not to keep cache across open but kernel still keeps it? > The caller should call invalidate_inode_pages2() in another place, for example, in our case: @@ -259,6 +264,12 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir) if (is_wb_truncate | dax_truncate) { fuse_release_nowrite(inode); + /* + * Only call invalidate_inode_pages2() after removing + * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. + */ + if (!keep_cache) + invalidate_inode_pages2(inode->i_mapping); inode_unlock(inode); } Thanks, Yongji