Ext4: A Case-insensitive Linux Filesystem
summary
Provides in-kernel, high-performance case-insensitive name lookups by adding a Unicode subsystem and APIs plus Ext4 changes merged into Linux 5.2. It auto-generates a forest of lookup trees from the Unicode UCD at build time, supports UTF‑8 C‑normalization and casefold, and records the Unicode version per filesystem stores Unicode version in superblock to avoid future collisions. Ext4 caches normalized names (improving lookups in 5.3), while FS‑crypt and overlayfs integration and negative‑dentry handling remain work in progress.
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chapters (16)
- 0:00Intro
- 0:33What is a caseinsensitive file system
- 1:02Why caseinsensitive
- 4:17How to implement it
- 6:21Semantics
- 8:54Unicode
- 11:55Normalization
- 14:48Kernel API
- 17:48Build Process
- 18:30Character Lookup
- 19:06Unicode Subsystem
- 19:29Basic Idea
- 20:26Details
- 21:24Performance
- 25:30Current Status
- 26:53Questions
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