Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ext4: add support for 32-bit default reserved uid and gid values
Support for specifying the default user id and group id that is
allowed to use the reserved block space was added way back when Linux
only supported 16-bit uid's and gid's. (Yeah, that long ago.) It's
not a commonly used feature, but let's add support for 32-bit user and
group id's.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Message-ID: <20250916-tune2fs-v2-2-d594dc7486f0@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+19
-5
+15
-1
fs/ext4/ext4.h
+15
-1
fs/ext4/ext4.h
···
1442
1442
__le16 s_encoding; /* Filename charset encoding */
1443
1443
__le16 s_encoding_flags; /* Filename charset encoding flags */
1444
1444
__le32 s_orphan_file_inum; /* Inode for tracking orphan inodes */
1445
-
__le32 s_reserved[94]; /* Padding to the end of the block */
1445
+
__le16 s_def_resuid_hi;
1446
+
__le16 s_def_resgid_hi;
1447
+
__le32 s_reserved[93]; /* Padding to the end of the block */
1446
1448
__le32 s_checksum; /* crc32c(superblock) */
1447
1449
};
1448
1450
···
1812
1810
return ino == EXT4_ROOT_INO ||
1813
1811
(ino >= EXT4_FIRST_INO(sb) &&
1814
1812
ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1813
+
}
1814
+
1815
+
static inline int ext4_get_resuid(struct ext4_super_block *es)
1816
+
{
1817
+
return le16_to_cpu(es->s_def_resuid) |
1818
+
le16_to_cpu(es->s_def_resuid_hi) << 16;
1819
+
}
1820
+
1821
+
static inline int ext4_get_resgid(struct ext4_super_block *es)
1822
+
{
1823
+
return le16_to_cpu(es->s_def_resgid) |
1824
+
le16_to_cpu(es->s_def_resgid_hi) << 16;
1815
1825
}
1816
1826
1817
1827
/*
+4
-4
fs/ext4/super.c
+4
-4
fs/ext4/super.c
···
2960
2960
}
2961
2961
2962
2962
if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2963
-
le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2963
+
ext4_get_resuid(es) != EXT4_DEF_RESUID)
2964
2964
SEQ_OPTS_PRINT("resuid=%u",
2965
2965
from_kuid_munged(&init_user_ns, sbi->s_resuid));
2966
2966
if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2967
-
le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2967
+
ext4_get_resgid(es) != EXT4_DEF_RESGID)
2968
2968
SEQ_OPTS_PRINT("resgid=%u",
2969
2969
from_kgid_munged(&init_user_ns, sbi->s_resgid));
2970
2970
def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
···
5279
5279
5280
5280
ext4_set_def_opts(sb, es);
5281
5281
5282
-
sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5283
-
sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5282
+
sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
5283
+
sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
5284
5284
sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5285
5285
sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5286
5286
sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;