Update cheatsheets

linux/btrfs-check

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+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# btrfs check
+
+> Check or repair a btrfs filesystem.
+> More information: <https://btrfs.readthedocs.io/en/latest/btrfs-check.html>.
+
+- Check a btrfs filesystem:
+
+`sudo btrfs check {{path/to/partition}}`
+
+- Check and repair a btrfs filesystem (dangerous):
+
+`sudo btrfs check --repair {{path/to/partition}}`
+
+- Show the progress of the check:
+
+`sudo btrfs check --progress {{path/to/partition}}`
+
+- Verify the checksum of each data block (if the filesystem is good):
+
+`sudo btrfs check --check-data-csum {{path/to/partition}}`
+
+- Use the `n`-th superblock (`n` can be 0, 1 or 2):
+
+`sudo btrfs check --super {{n}} {{path/to/partition}}`
+
+- Rebuild the checksum tree:
+
+`sudo btrfs check --repair --init-csum-tree {{path/to/partition}}`
+
+- Rebuild the extent tree:
+
+`sudo btrfs check --repair --init-extent-tree {{path/to/partition}}`