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authorDaniel Rosenberg <drosen@google.com>2019-07-24 02:05:28 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2019-08-23 17:57:13 +0300
commit5aba54302a46fdd589040b928d5d010e5ace1234 (patch)
tree8b6cc699256578666a66b49f8b72ae2eae36c143 /Documentation/filesystems
parent71e90b4654a9298f9e2375cc733d57b8bf92ce73 (diff)
downloadlinux-5aba54302a46fdd589040b928d5d010e5ace1234.tar.xz
f2fs: include charset encoding information in the superblock
Add charset encoding to f2fs to support casefolding. It is modeled after the same feature introduced in commit c83ad55eaa91 ("ext4: include charset encoding information in the superblock") Currently this is not compatible with encryption, similar to the current ext4 imlpementation. This will change in the future. >From the ext4 patch: """ The s_encoding field stores a magic number indicating the encoding format and version used globally by file and directory names in the filesystem. The s_encoding_flags defines policies for using the charset encoding, like how to handle invalid sequences. The magic number is mapped to the exact charset table, but the mapping is specific to ext4. Since we don't have any commitment to support old encodings, the only encoding I am supporting right now is utf8-12.1.0. The current implementation prevents the user from enabling encoding and per-directory encryption on the same filesystem at the same time. The incompatibility between these features lies in how we do efficient directory searches when we cannot be sure the encryption of the user provided fname will match the actual hash stored in the disk without decrypting every directory entry, because of normalization cases. My quickest solution is to simply block the concurrent use of these features for now, and enable it later, once we have a better solution. """ Signed-off-by: Daniel Rosenberg <drosen@google.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/f2fs.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 496fa28b2492..5fa38ab373ca 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -413,6 +413,9 @@ Files in /sys/fs/f2fs/<devname>
that would be unusable if checkpoint=disable were
to be set.
+encoding This shows the encoding used for casefolding.
+ If casefolding is not enabled, returns (none)
+
================================================================================
USAGE
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