Messages in this thread Patch in this message | | | From | Luis Henriques <> | Subject | [PATCH 3.5 06/62] ext4: don't try to modify s_flags if the the file system is read-only | Date | Wed, 5 Mar 2014 14:36:10 +0000 |
| |
3.5.7.32 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Theodore Ts'o <tytso@mit.edu>
commit 23301410972330c0ae9a8afc379ba2005e249cc6 upstream.
If an ext4 file system is created by some tool other than mke2fs (perhaps by someone who has a pathalogical fear of the GPL) that doesn't set one or the other of the EXT2_FLAGS_{UN}SIGNED_HASH flags, and that file system is then mounted read-only, don't try to modify the s_flags field. Otherwise, if dm_verity is in use, the superblock will change, causing an dm_verity failure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/ext4/super.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index b2ae1e8..44884b7 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3548,16 +3548,22 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) 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; - i = le32_to_cpu(es->s_flags); - if (i & EXT2_FLAGS_UNSIGNED_HASH) - sbi->s_hash_unsigned = 3; - else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) { + if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) { + i = le32_to_cpu(es->s_flags); + if (i & EXT2_FLAGS_UNSIGNED_HASH) + sbi->s_hash_unsigned = 3; + else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) { #ifdef __CHAR_UNSIGNED__ - es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH); - sbi->s_hash_unsigned = 3; + if (!(sb->s_flags & MS_RDONLY)) + es->s_flags |= + cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH); + sbi->s_hash_unsigned = 3; #else - es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH); + if (!(sb->s_flags & MS_RDONLY)) + es->s_flags |= + cpu_to_le32(EXT2_FLAGS_SIGNED_HASH); #endif + } } /* Handle clustersize */ -- 1.9.0
| |