erofs: allow 16-byte volume name again

Actually, volume name doesn't need to include the NIL terminator if
the string length matches the on-disk field size as mentioned in [1].

I tend to relax it together with the upcoming 48-bit block addressing
(or stable kernels which backport this fix) so that we could have a
chance to record a 16-byte volume name like ext4.

Since in-memory `volume_name` has no user, just get rid of the unneeded
check for now.  `sbi->uuid` is useless and avoid it too.

[1] https://lore.kernel.org/r/96efe46b-dcce-4490-bba1-a0b00932d1cc@linux.alibaba.com

Fixes: a64d9493f587 ("staging: erofs: refuse to mount images with malformed volume name")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250225033934.2542635-1-hsiangkao@linux.alibaba.com

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f955793146f40cbc47f589b14d3572a8f0d39ae3..b452b6557aa5126bea5bfaf2e85a436cd89af346 100644 (file)
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -152,8 +152,6 @@ struct erofs_sb_info {
        /* used for statfs, f_files - f_favail */
        u64 inos;
 
-       u8 uuid[16];                    /* 128-bit uuid for volume */
-       u8 volume_name[16];             /* volume name */
        u32 feature_compat;
        u32 feature_incompat;
 

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 3dc86d931ef152530205c16a34fc5a622989c7f6..19e52ffa34c5b4cabf03511c7b925308e79d7e3d 100644 (file)
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -317,14 +317,6 @@ static int erofs_read_superblock(struct super_block *sb)
 
        super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid));
 
-       ret = strscpy(sbi->volume_name, dsb->volume_name,
-                     sizeof(dsb->volume_name));
-       if (ret < 0) {  /* -E2BIG */
-               erofs_err(sb, "bad volume name without NIL terminator");
-               ret = -EFSCORRUPTED;
-               goto out;
-       }
-
        /* parse on-disk compression configurations */
        ret = z_erofs_parse_cfgs(sb, dsb);
        if (ret < 0)