[PATCH 4.14 016/237] ext4: fix support for inode sizes > 1024 bytes

Greg Kroah-Hartman
2020-02-27T14:40:51Z

From: Theodore Ts'o <tytso@mit.edu>

commit 4f97a68192bd33b9963b400759cef0ca5963af00 upstream.

A recent commit, 9803387c55f7 ("ext4: validate the
debug_want_extra_isize mount option at parse time"), moved mount-time
checks around. One of those changes moved the inode size check before
the blocksize variable was set to the blocksize of the file system.
After 9803387c55f7 was set to the minimum allowable blocksize, which
in practice on most systems would be 1024 bytes. This cuased file
systems with inode sizes larger than 1024 bytes to be rejected with a
message:

EXT4-fs (sdXX): unsupported inode size: 4096

Fixes: 9803387c55f7 ("ext4: validate the debug_want_extra_isize mount option at parse time")
Link: https://lore.kernel.org/r/20200206225252.GA3673@mit.edu
Reported-by: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ext4/super.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3668,6 +3668,15 @@ static int ext4_fill_super(struct super_
*/
sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;

+ blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
+ if (blocksize < EXT4_MIN_BLOCK_SIZE ||
+ blocksize > EXT4_MAX_BLOCK_SIZE) {
+ ext4_msg(sb, KERN_ERR,
+ "Unsupported filesystem blocksize %d (%d log_block_size)",
+ blocksize, le32_to_cpu(es->s_log_block_size));
+ goto failed_mount;
+ }
+
if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
@@ -3685,6 +3694,7 @@ static int ext4_fill_super(struct super_
ext4_msg(sb, KERN_ERR,
"unsupported inode size: %d",
sbi->s_inode_size);
+ ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
goto failed_mount;
}
/*
@@ -3848,14 +3858,6 @@ static int ext4_fill_super(struct super_
if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
goto failed_mount;

- blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
- if (blocksize < EXT4_MIN_BLOCK_SIZE ||
- blocksize > EXT4_MAX_BLOCK_SIZE) {
- ext4_msg(sb, KERN_ERR,
- "Unsupported filesystem blocksize %d (%d log_block_size)",
- blocksize, le32_to_cpu(es->s_log_block_size));
- goto failed_mount;
- }
if (le32_to_cpu(es->s_log_block_size) >
(EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
ext4_msg(sb, KERN_ERR,