From: Theodore Ts'o 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 --- fs/ext4/ext4.h | 16 +++++++++++++++- fs/ext4/super.c | 8 ++++---- 2 files changed, 19 insertions(+), 5 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 01a6e2de7fc3ef0e20b039d3200b9c9bd656f59f..4bfcd5f0c74fda30db4009ee28fbee00a2f6b76f 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1442,7 +1442,9 @@ struct ext4_super_block { __le16 s_encoding; /* Filename charset encoding */ __le16 s_encoding_flags; /* Filename charset encoding flags */ __le32 s_orphan_file_inum; /* Inode for tracking orphan inodes */ - __le32 s_reserved[94]; /* Padding to the end of the block */ + __le16 s_def_resuid_hi; + __le16 s_def_resgid_hi; + __le32 s_reserved[93]; /* Padding to the end of the block */ __le32 s_checksum; /* crc32c(superblock) */ }; @@ -1812,6 +1814,18 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino) ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)); } +static inline int ext4_get_resuid(struct ext4_super_block *es) +{ + return(le16_to_cpu(es->s_def_resuid) | + (le16_to_cpu(es->s_def_resuid_hi) << 16)); +} + +static inline int ext4_get_resgid(struct ext4_super_block *es) +{ + return(le16_to_cpu(es->s_def_resgid) | + (le16_to_cpu(es->s_def_resgid_hi) << 16)); +} + /* * Returns: sbi->field[index] * Used to access an array element from the following sbi fields which require diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 94c98446c84f9a4614971d246ca7f001de610a8a..0256c8f7c6cee2b8d9295f2fa9a7acd904382e83 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2951,11 +2951,11 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb, } if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) || - le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) + ext4_get_resuid(es) != EXT4_DEF_RESUID) SEQ_OPTS_PRINT("resuid=%u", from_kuid_munged(&init_user_ns, sbi->s_resuid)); if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) || - le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) + ext4_get_resgid(es) != EXT4_DEF_RESGID) SEQ_OPTS_PRINT("resgid=%u", from_kgid_munged(&init_user_ns, sbi->s_resgid)); def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors); @@ -5270,8 +5270,8 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) ext4_set_def_opts(sb, es); - sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid)); - sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid)); + sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es)); + sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es)); sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ; sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME; sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME; -- 2.51.0