diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_dir2.h')
| -rw-r--r-- | fs/xfs/libxfs/xfs_dir2.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h index dd39f17dd9a9..19af22a16c41 100644 --- a/fs/xfs/libxfs/xfs_dir2.h +++ b/fs/xfs/libxfs/xfs_dir2.h @@ -248,4 +248,35 @@ unsigned int xfs_dir3_data_end_offset(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr); bool xfs_dir2_namecheck(const void *name, size_t length); +/* + * The "ascii-ci" feature was created to speed up case-insensitive lookups for + * a Samba product. Because of the inherent problems with CI and UTF-8 + * encoding, etc, it was decided that Samba would be configured to export + * latin1/iso 8859-1 encodings as that covered >90% of the target markets for + * the product. Hence the "ascii-ci" casefolding code could be encoded into + * the XFS directory operations and remove all the overhead of casefolding from + * Samba. + * + * To provide consistent hashing behavior between the userspace and kernel, + * these functions prepare names for hashing by transforming specific bytes + * to other bytes. Robustness with other encodings is not guaranteed. + */ +static inline bool xfs_ascii_ci_need_xfrm(unsigned char c) +{ + if (c >= 0x41 && c <= 0x5a) /* A-Z */ + return true; + if (c >= 0xc0 && c <= 0xd6) /* latin A-O with accents */ + return true; + if (c >= 0xd8 && c <= 0xde) /* latin O-Y with accents */ + return true; + return false; +} + +static inline unsigned char xfs_ascii_ci_xfrm(unsigned char c) +{ + if (xfs_ascii_ci_need_xfrm(c)) + c -= 'A' - 'a'; + return c; +} + #endif /* __XFS_DIR2_H__ */ |