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FAT file systems do not use inodes, instead all file meta-information is stored in directory entries. FAT12 and FAT16 use a fixed size area for root directories, with typically 512 entries of 32 bytes each (for a total of 16 KB) on hard disk formats. The file system data is stored in clusters of typically 512 to 4096 bytes, depending on the size of the file system. The current code uses the offset of a DOS 8.3 style directory entry as a pseudo-inode, which leads to inode values of 0 to 16368 for typical root directories with 512 entries. Sub-directories use 2 cluster length plus the byte offset of the directory entry in the data area for the pseudo-inode, which may be as low as 1024 in case of 512 byte clusters. A sub-directory in cluster 2 and with 512 byte clusters will therefore lead to a re-use of inode 1024 when there are at least 32 DOS 8.3 style filenames in the root directory (or 11 14-character Windows long file names, each of which takes up 3 directory entries). FAT32 file systems are not affected by this issue and FAT12/FAT16 file systems with larger cluster sizes are unlikely to have as many directory entries in the root directory as are required to cause the collision. This commit leads to inode numbers that are guaranteed to not collide for all valid FAT12 and FAT16 file system parameters. It does also provide a small speed-up due to more efficient use of the vnode cache. Approved by: mckusick MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D43978 |
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| .. | ||
| amd64 | ||
| arm | ||
| arm64 | ||
| bsm | ||
| cam | ||
| cddl | ||
| compat | ||
| conf | ||
| contrib | ||
| crypto | ||
| ddb | ||
| dev | ||
| dts | ||
| fs | ||
| gdb | ||
| geom | ||
| gnu | ||
| i386 | ||
| isa | ||
| kern | ||
| kgssapi | ||
| libkern | ||
| modules | ||
| net | ||
| net80211 | ||
| netgraph | ||
| netinet | ||
| netinet6 | ||
| netipsec | ||
| netlink | ||
| netpfil | ||
| netsmb | ||
| nfs | ||
| nfsclient | ||
| nfsserver | ||
| nlm | ||
| ofed | ||
| opencrypto | ||
| powerpc | ||
| riscv | ||
| rpc | ||
| security | ||
| sys | ||
| teken | ||
| tests | ||
| tools | ||
| ufs | ||
| vm | ||
| x86 | ||
| xdr | ||
| xen | ||
| Makefile | ||
| README.md | ||
FreeBSD Kernel Source:
This directory contains the source files and build glue that make up the FreeBSD kernel and its modules, including both original and contributed software.
Kernel configuration files are located in the conf/ subdirectory of each
architecture. GENERIC is the configuration used in release builds. NOTES
contains documentation of all possible entries. LINT is a compile-only
configuration used to maximize build coverage and detect regressions.
Documentation:
Source code documentation is maintained in a set of man pages, under section 9.
These pages are located in share/man/man9, from the
top-level of the src tree. Consult intro(9)
for an overview of existing pages.
Some additional high-level documentation of the kernel is maintained in the Architecture Handbook.
Source Roadmap:
| Directory | Description |
|---|---|
| amd64 | AMD64 (64-bit x86) architecture support |
| arm | 32-bit ARM architecture support |
| arm64 | 64-bit ARM (AArch64) architecture support |
| cam | Common Access Method storage subsystem - cam(4) and ctl(4) |
| cddl | CDDL-licensed optional sources such as DTrace |
| conf | kernel build glue |
| compat | Linux compatibility layer, FreeBSD 32-bit compatibility |
| contrib | 3rd-party imported software such as OpenZFS |
| crypto | crypto drivers |
| ddb | interactive kernel debugger - ddb(4) |
| fs | most filesystems, excluding UFS, NFS, and ZFS |
| dev | device drivers and other arch independent code |
| gdb | kernel remote GDB stub - gdb(4) |
| geom | GEOM framework - geom(4) |
| i386 | i386 (32-bit x86) architecture support |
| kern | main part of the kernel |
| libkern | libc-like and other support functions for kernel use |
| modules | kernel module infrastructure |
| net | core networking code |
| net80211 | wireless networking (IEEE 802.11) - net80211(4) |
| netgraph | graph-based networking subsystem - netgraph(4) |
| netinet | IPv4 protocol implementation - inet(4) |
| netinet6 | IPv6 protocol implementation - inet6(4) |
| netipsec | IPsec protocol implementation - ipsec(4) |
| netpfil | packet filters - ipfw(4), pf(4), and ipfilter(4) |
| opencrypto | OpenCrypto framework - crypto(7) |
| powerpc | PowerPC/POWER (32 and 64-bit) architecture support |
| riscv | 64-bit RISC-V architecture support |
| security | security facilities - audit(4) and mac(4) |
| sys | kernel headers |
| tests | kernel unit tests |
| ufs | Unix File System - ffs(7) |
| vm | virtual memory system |
| x86 | code shared by AMD64 and i386 architectures |