53b381b3ab
This builds on David Woodhouse's original Btrfs raid5/6 implementation. The code has changed quite a bit, blame Chris Mason for any bugs. Read/modify/write is done after the higher levels of the filesystem have prepared a given bio. This means the higher layers are not responsible for building full stripes, and they don't need to query for the topology of the extents that may get allocated during delayed allocation runs. It also means different files can easily share the same stripe. But, it does expose us to incorrect parity if we crash or lose power while doing a read/modify/write cycle. This will be addressed in a later commit. Scrub is unable to repair crc errors on raid5/6 chunks. Discard does not work on raid5/6 (yet) The stripe size is fixed at 64KiB per disk. This will be tunable in a later commit. Signed-off-by: Chris Mason <chris.mason@fusionio.com>
55 lines
1.8 KiB
Plaintext
55 lines
1.8 KiB
Plaintext
config BTRFS_FS
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tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
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depends on EXPERIMENTAL
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select LIBCRC32C
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select ZLIB_INFLATE
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select ZLIB_DEFLATE
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select LZO_COMPRESS
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select LZO_DECOMPRESS
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select RAID6_PQ
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help
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Btrfs is a new filesystem with extents, writable snapshotting,
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support for multiple devices and many more features.
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Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
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FINALIZED. You should say N here unless you are interested in
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testing Btrfs with non-critical data.
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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 btrfs.
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If unsure, say N.
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config BTRFS_FS_POSIX_ACL
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bool "Btrfs POSIX Access Control Lists"
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depends on BTRFS_FS
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select FS_POSIX_ACL
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help
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POSIX Access Control Lists (ACLs) support permissions for users and
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groups beyond the owner/group/world scheme.
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To learn more about Access Control Lists, visit the POSIX ACLs for
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Linux website <http://acl.bestbits.at/>.
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If you don't know what Access Control Lists are, say N
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config BTRFS_FS_CHECK_INTEGRITY
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bool "Btrfs with integrity check tool compiled in (DANGEROUS)"
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depends on BTRFS_FS
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help
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Adds code that examines all block write requests (including
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writes of the super block). The goal is to verify that the
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state of the filesystem on disk is always consistent, i.e.,
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after a power-loss or kernel panic event the filesystem is
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in a consistent state.
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If the integrity check tool is included and activated in
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the mount options, plenty of kernel memory is used, and
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plenty of additional CPU cycles are spent. Enabling this
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functionality is not intended for normal use.
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In most cases, unless you are a btrfs developer who needs
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to verify the integrity of (super)-block write requests
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during the run of a regression test, say N
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