[Resend, but also rebased on top of Ted's dev branch.] Hi Ted, This patchset implements encoding support as a superblock feature, valid for the entire disk, and Case-insensitive lookups support as a per-directory feature, configured as an inode flag. Alongside the addition of the casefolding patch, which was not part of v1, I fixed some bugs and addressed the concerns raised regarding invalid sequences and what normalization we use. My approach to solve the two problems above is to make things more flexible. An encoding flags field in the superblock registers what kind of normalization is used by the filesystem. Right now, the only encoding supported for utf8 is NFKD, for instance, but if we want to support a different normalization function in the future, we can be backward compatible. Likewise, superblock flags also define the behavior when dealing with invalid sequences. The default behavior is to just treat invalid sequences as opaque byte sequences, falling back to the original behavior. Alternatively if the strict flag is enabled, the kernel will reject invalid sequences as soon as they are detected. All these flags, can only be set at mkfs time, using the encoding_flags parameter. Each encoding has its default flags, when creating the filesystem in mkfs, regarding normalization/casefold functions and how to deal with opaque sequences. The NLS patches implement generic casefold and normalization operation (defined as tolower() and identity(), respectively), allowing us to use any NLS charset in the kernel. We store the NLS charset as a magic number in the superblock, and for that only a few charsets are defined. If you want to force a different charset, the encoding and encoding_flags mount options are also provided. This patchset also includes the NLS changes that I am proposing, including the entire utf8 normalization implementation. Differently from the previous version, I merged utf8 and utf8n, allowing the user to request a specific normalization (or no normalization at all) using the flags. As usual, I did not include the source ucd files because they would bounce in the list, but a completely functional implementation can be found at: https://gitlab.collabora.com/krisman/linux.git -b ext4-ci-directory I am also not supporting encoding with encrypted directories, given the cost of searching encrypted directories where the diggested name is not normalized. This means that we need to decrypt each filename beforehand, so I decided to simply skip this for now. If the user tries to mount with encoding a directory that has the encryption feature, we simply bail out saying it is not supported. The patchset survives without failures the smoke tests of xfstests, with the obvious exception of generic/453. This test, which verifies that multiple files having equivalent names (which would match in utf8 normalization) are not the same file, doesn't really make sense with this patchset, since it basically verifies the fs is *not* encoding aware. We also developed encoding and casefolding tests for xfstests, allowing us to quickly verify the implementation. I will be sumitting them upstream too, but for now they are available at: https://gitlab.collabora.com/krisman/xfstests.git -b encoding These tests validate the usage on inline dirs, on dx directories, when dealing with dcache and more. I am happy with the coverage we have now, but if you have specific concerns I can add more tests. A modified version of e2fsprogs is necessary to run the tests, and to enable the feature. Support for mkfs, fsck, lsattr, chattr is available. I also hacked tune2fs to prevent it from setting the encryption flag when encoding is enabled. This tune2fs change is temporary until we are able to support these two features together. https://gitlab.collabora.com/krisman/e2fsprogs.git -b encoding-feature Gabriel Krisman Bertazi (21): nls: Wrap uni2char/char2uni callers nls: Wrap charset field access nls: Wrap charset hooks in ops structure nls: Split default charset from NLS core nls: Split struct nls_charset from struct nls_table nls: Add support for multiple versions of an encoding nls: Implement NLS_STRICT_MODE flag nls: Let charsets define the behavior of tolower/toupper nls: Add new interface for string comparisons nls: Add optional normalization and casefold hooks nls: ascii: Support validation and normalization operations nls: utf8: Move nls-utf8{,-core}.c nls: utf8: Integrate utf8 normalization code with utf8 charset nls: utf8: Introduce test module for normalized utf8 implementation vfs: Handle case-exact lookup in d_add_ci ext4: Include encoding information in the superblock ext4: Add encoding mount options ext4: Support encoding-aware file name lookups ext4: Implement encoding-aware dcache hooks ext4: Implement EXT4_CASEFOLD_FL flag docs: ext4.rst: Document encoding and case-insensitive lookups Olaf Weber (4): nls: utf8n: Add unicode character database files scripts: add trie generator for UTF-8 nls: utf8: Introduce code for UTF-8 normalization nls: utf8n: reduce the size of utf8data[] Documentation/filesystems/ext4/ext4.rst | 38 + fs/befs/linuxvfs.c | 8 +- fs/cifs/cifs_unicode.c | 15 +- fs/cifs/cifsfs.c | 2 +- fs/cifs/connect.c | 2 +- fs/cifs/dir.c | 7 +- fs/dcache.c | 33 +- fs/ext4/dir.c | 59 + fs/ext4/ext4.h | 33 +- fs/ext4/hash.c | 38 +- fs/ext4/ialloc.c | 2 +- fs/ext4/inline.c | 2 +- fs/ext4/inode.c | 4 +- fs/ext4/ioctl.c | 18 + fs/ext4/namei.c | 99 +- fs/ext4/super.c | 170 ++ fs/fat/dir.c | 13 +- fs/fat/inode.c | 6 +- fs/fat/namei_vfat.c | 6 +- fs/hfs/super.c | 6 +- fs/hfs/trans.c | 9 +- fs/hfsplus/options.c | 2 +- fs/hfsplus/unicode.c | 6 +- fs/isofs/inode.c | 5 +- fs/isofs/joliet.c | 3 +- fs/jfs/jfs_unicode.c | 9 +- fs/jfs/super.c | 3 +- fs/nls/Kconfig | 15 + fs/nls/Makefile | 20 + fs/nls/mac-celtic.c | 34 +- fs/nls/mac-centeuro.c | 34 +- fs/nls/mac-croatian.c | 34 +- fs/nls/mac-cyrillic.c | 34 +- fs/nls/mac-gaelic.c | 34 +- fs/nls/mac-greek.c | 34 +- fs/nls/mac-iceland.c | 34 +- fs/nls/mac-inuit.c | 34 +- fs/nls/mac-roman.c | 34 +- fs/nls/mac-romanian.c | 34 +- fs/nls/mac-turkish.c | 34 +- fs/nls/nls_ascii.c | 84 +- fs/nls/nls_core.c | 163 ++ fs/nls/nls_cp1250.c | 34 +- fs/nls/nls_cp1251.c | 34 +- fs/nls/nls_cp1255.c | 36 +- fs/nls/nls_cp437.c | 34 +- fs/nls/nls_cp737.c | 34 +- fs/nls/nls_cp775.c | 34 +- fs/nls/nls_cp850.c | 34 +- fs/nls/nls_cp852.c | 34 +- fs/nls/nls_cp855.c | 34 +- fs/nls/nls_cp857.c | 34 +- fs/nls/nls_cp860.c | 34 +- fs/nls/nls_cp861.c | 34 +- fs/nls/nls_cp862.c | 34 +- fs/nls/nls_cp863.c | 34 +- fs/nls/nls_cp864.c | 34 +- fs/nls/nls_cp865.c | 34 +- fs/nls/nls_cp866.c | 34 +- fs/nls/nls_cp869.c | 34 +- fs/nls/nls_cp874.c | 36 +- fs/nls/nls_cp932.c | 36 +- fs/nls/nls_cp936.c | 36 +- fs/nls/nls_cp949.c | 36 +- fs/nls/nls_cp950.c | 36 +- fs/nls/{nls_base.c => nls_default.c} | 124 +- fs/nls/nls_euc-jp.c | 29 +- fs/nls/nls_iso8859-1.c | 34 +- fs/nls/nls_iso8859-13.c | 34 +- fs/nls/nls_iso8859-14.c | 34 +- fs/nls/nls_iso8859-15.c | 34 +- fs/nls/nls_iso8859-2.c | 34 +- fs/nls/nls_iso8859-3.c | 34 +- fs/nls/nls_iso8859-4.c | 34 +- fs/nls/nls_iso8859-5.c | 34 +- fs/nls/nls_iso8859-6.c | 34 +- fs/nls/nls_iso8859-7.c | 34 +- fs/nls/nls_iso8859-9.c | 34 +- fs/nls/nls_koi8-r.c | 34 +- fs/nls/nls_koi8-ru.c | 30 +- fs/nls/nls_koi8-u.c | 34 +- fs/nls/nls_utf8-core.c | 333 +++ fs/nls/nls_utf8-norm.c | 797 ++++++ fs/nls/nls_utf8-selftest.c | 307 ++ fs/nls/nls_utf8.c | 67 - fs/nls/ucd/README | 33 + fs/nls/utf8n.h | 117 + fs/ntfs/inode.c | 2 +- fs/ntfs/super.c | 6 +- fs/ntfs/unistr.c | 13 +- fs/udf/super.c | 3 +- fs/udf/unicode.c | 4 +- include/linux/fs.h | 2 + include/linux/nls.h | 293 +- scripts/Makefile | 1 + scripts/mkutf8data.c | 3464 +++++++++++++++++++++++ 96 files changed, 7482 insertions(+), 633 deletions(-) create mode 100644 fs/nls/nls_core.c rename fs/nls/{nls_base.c => nls_default.c} (89%) create mode 100644 fs/nls/nls_utf8-core.c create mode 100644 fs/nls/nls_utf8-norm.c create mode 100644 fs/nls/nls_utf8-selftest.c delete mode 100644 fs/nls/nls_utf8.c create mode 100644 fs/nls/ucd/README create mode 100644 fs/nls/utf8n.h create mode 100644 scripts/mkutf8data.c -- 2.19.0
