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925c86a19b
Add a new config option that controls building the buffer_head code, and select it from all file systems and stacking drivers that need it. For the block device nodes and alternative iomap based buffered I/O path is provided when buffer_head support is not enabled, and iomap needs a a small tweak to define the IOMAP_F_BUFFER_HEAD flag to 0 to not call into the buffer_head code when it doesn't exist. Otherwise this is just Kconfig and ifdef changes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20230801172201.1923299-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
28 lines
1.2 KiB
Plaintext
28 lines
1.2 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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config NILFS2_FS
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tristate "NILFS2 file system support"
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select BUFFER_HEAD
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select CRC32
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select LEGACY_DIRECT_IO
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help
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NILFS2 is a log-structured file system (LFS) supporting continuous
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snapshotting. In addition to versioning capability of the entire
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file system, users can even restore files mistakenly overwritten or
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destroyed just a few seconds ago. Since this file system can keep
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consistency like conventional LFS, it achieves quick recovery after
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system crashes.
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NILFS2 creates a number of checkpoints every few seconds or per
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synchronous write basis (unless there is no change). Users can
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select significant versions among continuously created checkpoints,
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and can change them into snapshots which will be preserved for long
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periods until they are changed back to checkpoints. Each
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snapshot is mountable as a read-only file system concurrently with
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its writable mount, and this feature is convenient for online backup.
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Some features including atime, extended attributes, and POSIX ACLs,
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are not supported yet.
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To compile this file system support as a module, choose M here: the
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module will be called nilfs2. If unsure, say N.
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