"Theodore Ts'o" <tytso@xxxxxxx> writes:
> On Wed, 05 Jun 2024 09:23:35 +0800, Lizhi Xu wrote:
>> When mounting the ext4 filesystem, if the default hash version is set to
>> DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.
>>
>>
>
> Applied, thanks!
>
> [1/1] fs/ext4: Filesystem without casefold feature cannot be mounted with spihash
> commit: 985b67cd86392310d9e9326de941c22fc9340eec
Ted,
Since you took the above, can you please consider the following fixup?
I had pointed we shouldn't have siphash as the sb default hash at all:
based on your dev branch.
>8
Subject: [PATCH] ext4: Fix error message when rejecting the default hash
Commit 985b67cd8639 ("ext4: filesystems without casefold feature cannot
be mounted with siphash") properly rejects volumes where
s_def_hash_version is set to DX_HASH_SIPHASH, but the check and the
error message should not look into casefold setup - a filesystem should
never have DX_HASH_SIPHASH as the default hash. Fix it and, since we
are there, move the check to ext4_hash_info_init.
Fixes:985b67cd8639 ("ext4: filesystems without casefold feature cannot
be mounted with siphash")
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxx>
---
fs/ext4/ext4.h | 1 +
fs/ext4/super.c | 27 +++++++++++++++++----------
2 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 5845e4aa091a..4120f24880cb 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2462,6 +2462,7 @@ static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
#define DX_HASH_HALF_MD4_UNSIGNED 4
#define DX_HASH_TEA_UNSIGNED 5
#define DX_HASH_SIPHASH 6
+#define DX_HASH_LAST DX_HASH_SIPHASH
static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
const void *address, unsigned int length)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 25cd0d662e31..c6a34ad07ecc 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3582,13 +3582,6 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
"mounted without CONFIG_UNICODE");
return 0;
}
- if (EXT4_SB(sb)->s_es->s_def_hash_version == DX_HASH_SIPHASH &&
- !ext4_has_feature_casefold(sb)) {
- ext4_msg(sb, KERN_ERR,
- "Filesystem without casefold feature cannot be "
- "mounted with siphash");
- return 0;
- }
if (readonly)
return 1;
@@ -5094,16 +5087,27 @@ static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
return ret;
}
-static void ext4_hash_info_init(struct super_block *sb)
+static int ext4_hash_info_init(struct super_block *sb)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_super_block *es = sbi->s_es;
unsigned int i;
+ sbi->s_def_hash_version = es->s_def_hash_version;
+
+ if (sbi->s_def_hash_version > DX_HASH_LAST) {
+ ext4_msg(sb, KERN_ERR,
+ "Invalid default hash set in the superblock");
+ return -EINVAL;
+ } else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
+ ext4_msg(sb, KERN_ERR,
+ "SIPHASH is not a valid default hash value");
+ return -EINVAL;
+ }
+
for (i = 0; i < 4; i++)
sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
- sbi->s_def_hash_version = es->s_def_hash_version;
if (ext4_has_feature_dir_index(sb)) {
i = le32_to_cpu(es->s_flags);
if (i & EXT2_FLAGS_UNSIGNED_HASH)
@@ -5121,6 +5125,7 @@ static void ext4_hash_info_init(struct super_block *sb)
#endif
}
}
+ return 0;
}
static int ext4_block_group_meta_init(struct super_block *sb, int silent)
@@ -5256,7 +5261,9 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
if (err)
goto failed_mount;
- ext4_hash_info_init(sb);
+ err = ext4_hash_info_init(sb);
+ if (err)
+ goto failed_mount;
err = ext4_handle_clustersize(sb);
if (err)
--
2.46.0
