From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-110.freemail.mail.aliyun.com (out30-110.freemail.mail.aliyun.com [115.124.30.110]) (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 AEF4E27FB32; Fri, 9 Jan 2026 06:03:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.110 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767938620; cv=none; b=SJNBCER0xA1tCc285kS5kwhfPF4XyB3cr1wYw01obCfIoHaaJLLPm+tkkxQw+9DmL/gftQZn0BmP9DqkvDAMRTCiu7blFjix3ldWkvw9lM3RT/CmRFa2uiQS7MPaX6D6QB6ZGfALfvJRWok76nLJpnSCc5wIcPI6QeA3Cmm9+mY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767938620; c=relaxed/simple; bh=grGHqgFpfqMI3N2TJSrH8NfYKVEdLw29nJluqMQc7Ds=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UG+jsuRkT4cYW28Ey3k+J7XZaWhTg7Zy2u9b/ji+7zdsswhIOgp6ZymXHebVc49GwgvYSr0WgL+f5UtP/tOkISvBxgnNaXzGWv9v50DAgJMYjkjo7veqyHh0ghJwp9LWI3qUe7FTb329WwVdIS0bRwRMTdC3DJrEGusix1uPBPo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=E9po9ShY; arc=none smtp.client-ip=115.124.30.110 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="E9po9ShY" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1767938609; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=WSn8tUN5ji0ImOXN+znur1HXqv1SL9DZ3ghCylvKI/M=; b=E9po9ShYHg/Z3Zepkhl36gbtOA5nqX8HHJQAqSSj/JRQnEH2sQ6pQ6ShULNRHd1iSw62387yUFxAROey4IF49RZjnluuhEiVZePLU9vpoeg+tr+FhalcJfmfrOsIVFtw+scRdFBxAlYHhuu+R6bmD+foS22ETh1rdPfIwZWow8U= Received: from 30.221.131.232(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0Wwf8qgt_1767938608 cluster:ay36) by smtp.aliyun-inc.com; Fri, 09 Jan 2026 14:03:29 +0800 Message-ID: Date: Fri, 9 Jan 2026 14:03:28 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v13 01/10] iomap: stash iomap read ctx in the private field of iomap_iter To: Christoph Hellwig , "Darrick J. Wong" , Christian Brauner Cc: amir73il@gmail.com, linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org, Chao Yu , Hongbo Li References: <20260109030140.594936-1-lihongbo22@huawei.com> <20260109030140.594936-2-lihongbo22@huawei.com> From: Gao Xiang In-Reply-To: <20260109030140.594936-2-lihongbo22@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Christoph, Darrick, Christian, On 2026/1/9 11:01, Hongbo Li wrote: > It's useful to get filesystem-specific information using the > existing private field in the @iomap_iter passed to iomap_{begin,end} > for advanced usage for iomap buffered reads, which is much like the > current iomap DIO. > > For example, EROFS needs it to: > > - implement an efficient page cache sharing feature, since iomap > needs to apply to anon inode page cache but we'd like to get the > backing inode/fs instead, so filesystem-specific private data is > needed to keep such information; > > - pass in both struct page * and void * for inline data to avoid > kmap_to_page() usage (which is bogus). > > Signed-off-by: Hongbo Li > Reviewed-by: Gao Xiang Could you help review or ack this patch? This feature is almost in shape for the upcoming cycle, I do hope this iomap patch could be reviewed, thanks! Thanks, Gao Xiang > --- > fs/fuse/file.c | 4 ++-- > fs/iomap/buffered-io.c | 6 ++++-- > include/linux/iomap.h | 8 ++++---- > 3 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > index 01bc894e9c2b..f5d8887c1922 100644 > --- a/fs/fuse/file.c > +++ b/fs/fuse/file.c > @@ -979,7 +979,7 @@ static int fuse_read_folio(struct file *file, struct folio *folio) > return -EIO; > } > > - iomap_read_folio(&fuse_iomap_ops, &ctx); > + iomap_read_folio(&fuse_iomap_ops, &ctx, NULL); > fuse_invalidate_atime(inode); > return 0; > } > @@ -1081,7 +1081,7 @@ static void fuse_readahead(struct readahead_control *rac) > if (fuse_is_bad(inode)) > return; > > - iomap_readahead(&fuse_iomap_ops, &ctx); > + iomap_readahead(&fuse_iomap_ops, &ctx, NULL); > } > > static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to) > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index e5c1ca440d93..5f7dcbabbda3 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -555,13 +555,14 @@ static int iomap_read_folio_iter(struct iomap_iter *iter, > } > > void iomap_read_folio(const struct iomap_ops *ops, > - struct iomap_read_folio_ctx *ctx) > + struct iomap_read_folio_ctx *ctx, void *private) > { > struct folio *folio = ctx->cur_folio; > struct iomap_iter iter = { > .inode = folio->mapping->host, > .pos = folio_pos(folio), > .len = folio_size(folio), > + .private = private, > }; > size_t bytes_submitted = 0; > int ret; > @@ -620,13 +621,14 @@ static int iomap_readahead_iter(struct iomap_iter *iter, > * the filesystem to be reentered. > */ > void iomap_readahead(const struct iomap_ops *ops, > - struct iomap_read_folio_ctx *ctx) > + struct iomap_read_folio_ctx *ctx, void *private) > { > struct readahead_control *rac = ctx->rac; > struct iomap_iter iter = { > .inode = rac->mapping->host, > .pos = readahead_pos(rac), > .len = readahead_length(rac), > + .private = private, > }; > size_t cur_bytes_submitted; > > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > index 520e967cb501..441d614e9fdf 100644 > --- a/include/linux/iomap.h > +++ b/include/linux/iomap.h > @@ -341,9 +341,9 @@ ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, > const struct iomap_ops *ops, > const struct iomap_write_ops *write_ops, void *private); > void iomap_read_folio(const struct iomap_ops *ops, > - struct iomap_read_folio_ctx *ctx); > + struct iomap_read_folio_ctx *ctx, void *private); > void iomap_readahead(const struct iomap_ops *ops, > - struct iomap_read_folio_ctx *ctx); > + struct iomap_read_folio_ctx *ctx, void *private); > bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count); > struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len); > bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags); > @@ -595,7 +595,7 @@ static inline void iomap_bio_read_folio(struct folio *folio, > .cur_folio = folio, > }; > > - iomap_read_folio(ops, &ctx); > + iomap_read_folio(ops, &ctx, NULL); > } > > static inline void iomap_bio_readahead(struct readahead_control *rac, > @@ -606,7 +606,7 @@ static inline void iomap_bio_readahead(struct readahead_control *rac, > .rac = rac, > }; > > - iomap_readahead(ops, &ctx); > + iomap_readahead(ops, &ctx, NULL); > } > #endif /* CONFIG_BLOCK */ >