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See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 0D3D3180005 X-Stat-Signature: gwdkq6sdg55mzr4bpzneathjngs8nna4 X-HE-Tag: 1752133667-435225 X-HE-Meta: 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 2Xx0Lxwh BW3PzIw2zQ8NUvrWJvBpahf+lYhQdtxfPoJ2b8i2hrTNAPTL9bNDXtpuSbzXS7EmLPqLI9YIxEgWYg/8LjH68qvhKYUUuQUoAhv3ZV5jzTDWwmZpdEI/Gnja2R/xKIU78VDtDGnn/FKs/3qArSUWDP93xO0ivg1lyk3suVOe+zCaIYo0S3SfPKy+wuh5HiQQuqja99ZOBsG2w6q7Y2BJF+AMPPXRoZ3zCCo9W4iuZ4zQ0Ebhp9m6gxJ5Qrh2YBezjji6WaP/yLAT9/WM4tnR2Csr8sUTfXYh0cfV21SyFZnDv1xRhWGpjz3pFxlr5sKHMIgih52tTYYMJBsyymDtFj78NZmtDATFWzcVefY6ZVOCxu2+LK4spACJQuKShvw0F/LoKfqnw02R6+3bPV1mUrRAqZsHD5tTi+gGAykfKpCIMBHu17ipxqRixAWSy/VkNCtq8wu10AFdqNk2G5p0Z8rTBGm8G0Q8SyovS 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: List-Subscribe: List-Unsubscribe: On Tue, Jul 08, 2025 at 12:06:17PM -0400, Mike Snitzer wrote: > Add 'io_cache_read' to NFSD's debugfs interface so that: Any data > read by NFSD will either be: > - cached using page cache (NFSD_IO_BUFFERED=0) > - cached but removed from the page cache upon completion > (NFSD_IO_DONTCACHE=1). > - not cached (NFSD_IO_DIRECT=2) > > io_cache_read is 0 by default. It may be set by writing to: > /sys/kernel/debug/nfsd/io_cache_read > > If NFSD_IO_DONTCACHE is specified using 1, FOP_DONTCACHE must be > advertised as supported by the underlying filesystem (e.g. XFS), > otherwise all IO flagged with RWF_DONTCACHE will fail with > -EOPNOTSUPP. > > If NFSD_IO_DIRECT is specified using 2, the IO must be aligned > relative to the underlying block device's logical_block_size. Also the > memory buffer used to store the read must be aligned relative to the > underlying block device's dma_alignment. Does this also need some kind of check that direct I/O is supported at all by the file system / fops instance?