Commit 57945027 authored Feb 25, 2025 by Gao Xiang

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: a64d9493 ("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

parent 706e50e4

fs/erofs/internal.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -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;

fs/erofs/super.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -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)