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Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <8f88459a-97e0-8b8d-3ec9-260d482a0d38@linux.alibaba.com> References: <8f88459a-97e0-8b8d-3ec9-260d482a0d38@linux.alibaba.com> <20220118131216.85338-1-jefflexu@linux.alibaba.com> <2815558.1643127330@warthog.procyon.org.uk> To: JeffleXu Cc: dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, joseph.qi@linux.alibaba.com, bo.liu@linux.alibaba.com, tao.peng@linux.alibaba.com, gerry@linux.alibaba.com, eguan@linux.alibaba.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 00/20] fscache,erofs: fscache-based demand-read semantics MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <100894.1643187095.1@warthog.procyon.org.uk> Date: Wed, 26 Jan 2022 08:51:35 +0000 Message-ID: <100895.1643187095@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org JeffleXu wrote: > "/path/to/file+offset" > ^ > > Besides, what does the 'offset' mean? Assuming you're storing multiple erofs files within the same backend file, you need to tell the the cache backend how to find the data. Assuming the erofs data is arranged such that each erofs file is a single contiguous region, then you need a pathname and a file offset to find one of them. David