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bh=74aMisHJvcrsbS5g8R7662ZNEA+1A6hMiypJVvVd5yo=; b=D2SHVNFaVrDaOMXstah3E9Ncve1zCPNrv5du4jxn4QC/KvAeVNMvt47UYocxaDllK5eOe6 TUczKNUVrUpR/ib8YXL5kM2XPaiiaJ+Qb9d3Ll3R3rApbCvQZaWg9V1pigLgZ4SQrJJ+mt NRRMLH4hLNxSLi8XCFYTyVFeOE+iBGk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-271-zhDNyJpoN6uuRXwKl_ogyg-1; Fri, 19 May 2023 03:41:26 -0400 X-MC-Unique: zhDNyJpoN6uuRXwKl_ogyg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 591D03804098; Fri, 19 May 2023 07:41:25 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.221]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1119C2166B25; Fri, 19 May 2023 07:41:22 +0000 (UTC) From: David Howells To: Jens Axboe , Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , John Hubbard , Miklos Szeredi , linux-unionfs@vger.kernel.org Subject: [PATCH v20 07/32] overlayfs: Implement splice-read Date: Fri, 19 May 2023 08:40:22 +0100 Message-Id: <20230519074047.1739879-8-dhowells@redhat.com> In-Reply-To: <20230519074047.1739879-1-dhowells@redhat.com> References: <20230519074047.1739879-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 543DC20013 X-Stat-Signature: yof99n4m1qtzdfsmp86eugx61qw5uzr9 X-Rspam-User: X-HE-Tag: 1684482090-844376 X-HE-Meta: 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 V7Rg4tQ6 No/f28nzyXMUveGYk3XydHU9Qxty4gUogKlqi0Fls7NPR7MTQJ49k8aDew6QgSJgGJ/zG1cracWZFEuiwbQmetRUiJgWwoYNkoxn1o8AkF435ffcYlpzaxv7oln7UZUa4gkZ6HiAdvyskRGNx5Y2GPortSK++9NxVqZMvHIrK3HjbszO5TZaaYIC1d9vo4dX4vKAGd9PXsr9toHi4cH+R6Au7z00cC/CNk5q21uzvfeiV3mPWyYUssyK6/XymgAwuoyRUdrFx0cN/3hLyiO7jMKEJJIZdOuIQIj+ADBol0CAoOTXYBiCN//hEX0pg1rv1RJLm9I5JuyPToN/HSbjEBdU0v23LZfGNQsfgHwgubQDRJzgMgPfTjvanOcORai9Icxs1DMGL0gYD8Gtg0zTqHEI5z79PUrMTQkotir62bi5X6vyFMojwH1KRrA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Implement splice-read for overlayfs by passing the request down a layer rather than going through generic_file_splice_read() which is going to be changed to assume that ->read_folio() is present on buffered files. Signed-off-by: David Howells cc: Christoph Hellwig cc: Jens Axboe cc: Al Viro cc: John Hubbard cc: David Hildenbrand cc: Matthew Wilcox cc: Miklos Szeredi cc: linux-unionfs@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org --- Notes: ver #17) - Use vfs_splice_read() helper rather than open-coding checks. ver #15) - Remove redundant FMODE_CAN_ODIRECT check on real file. - Do rw_verify_area() on the real file, not the overlay file. - Fix a file leak. fs/overlayfs/file.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 7c04f033aadd..86197882ff35 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -419,6 +419,27 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) return ret; } +static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + const struct cred *old_cred; + struct fd real; + ssize_t ret; + + ret = ovl_real_fdget(in, &real); + if (ret) + return ret; + + old_cred = ovl_override_creds(file_inode(in)->i_sb); + ret = vfs_splice_read(real.file, ppos, pipe, len, flags); + revert_creds(old_cred); + ovl_file_accessed(in); + + fdput(real); + return ret; +} + /* * Calling iter_file_splice_write() directly from overlay's f_op may deadlock * due to lock order inversion between pipe->mutex in iter_file_splice_write() @@ -695,7 +716,7 @@ const struct file_operations ovl_file_operations = { .fallocate = ovl_fallocate, .fadvise = ovl_fadvise, .flush = ovl_flush, - .splice_read = generic_file_splice_read, + .splice_read = ovl_splice_read, .splice_write = ovl_splice_write, .copy_file_range = ovl_copy_file_range,