From: Ritesh Harjani riteshh@linux.ibm.com
commit f1eec3b0d0a849996ebee733b053efa71803dad5 upstream.
While calculating overhead for internal journal, also check that j_inum shouldn't be 0. Otherwise we get below error with xfstests generic/050 with external journal (XXX_LOGDEV config) enabled.
It could be simply reproduced with loop device with an external journal and marking blockdev as RO before mounting.
[ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode # ------------[ cut here ]------------ generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2) WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0 CPU: 107 PID: 115347 Comm: mount Tainted: G L --------- -t - 4.18.0-167.el8.ppc64le #1 NIP: c0000000006f6d44 LR: c0000000006f6d40 CTR: 0000000030041dd4 <...> NIP [c0000000006f6d44] generic_make_request_checks+0x6b4/0x7d0 LR [c0000000006f6d40] generic_make_request_checks+0x6b0/0x7d0 <...> Call Trace: generic_make_request_checks+0x6b0/0x7d0 (unreliable) generic_make_request+0x3c/0x420 submit_bio+0xd8/0x200 submit_bh_wbc+0x1e8/0x250 __sync_dirty_buffer+0xd0/0x210 ext4_commit_super+0x310/0x420 [ext4] __ext4_error+0xa4/0x1e0 [ext4] __ext4_iget+0x388/0xe10 [ext4] ext4_get_journal_inode+0x40/0x150 [ext4] ext4_calculate_overhead+0x5a8/0x610 [ext4] ext4_fill_super+0x3188/0x3260 [ext4] mount_bdev+0x778/0x8f0 ext4_mount+0x28/0x50 [ext4] mount_fs+0x74/0x230 vfs_kern_mount.part.6+0x6c/0x250 do_mount+0x2fc/0x1280 sys_mount+0x158/0x180 system_call+0x5c/0x70 EXT4-fs (pmem1p2): no journal found EXT4-fs (pmem1p2): can't get journal size EXT4-fs (pmem1p2): mounted filesystem without journal. Opts: dax,norecovery
Fixes: 3c816ded78bb ("ext4: use journal inode to determine journal overhead") Reported-by: Harish Sriram harish@linux.ibm.com Signed-off-by: Ritesh Harjani riteshh@linux.ibm.com Reviewed-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20200316093038.25485-1-riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/ext4/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3524,7 +3524,8 @@ int ext4_calculate_overhead(struct super */ if (sbi->s_journal && !sbi->journal_bdev) overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen); - else if (ext4_has_feature_journal(sb) && !sbi->s_journal) { + else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) { + /* j_inum for internal journal is non-zero */ j_inode = ext4_get_journal_inode(sb, j_inum); if (j_inode) { j_blocks = j_inode->i_size >> sb->s_blocksize_bits;