How to check if the block is present in a sparse file (for simple copy-on-write)?

Posted by Vi on Stack Overflow See other posts from Stack Overflow or by Vi
Published on 2010-04-01T20:05:13Z Indexed on 2010/04/01 20:13 UTC
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Filed under:

linux

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filesystem

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sparse

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copy-on-write

How to get sparse block size and check if data is present at the given offset in sparse file in reiserfs/ext3 in Linux?

I want to use it to implement simple copy-on-write block device using FUSE.

Or I should better keep a bitmap in a separate file?

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