From: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx> commit e4e58e5df309d695799c494958962100a4c25039 upstream. In __ext4_super() we always overwrote the user specified journal_ioprio value with a default value, expecting parse_apply_sb_mount_options() to later correctly set ctx->journal_ioprio to the user specified value. However, if parse_apply_sb_mount_options() returned early because of empty sbi->es_s->s_mount_opts, the correct journal_ioprio value was never set. This patch fixes __ext4_super() to only use the default value if the user has not specified any value for journal_ioprio. Similarly, the remount behavior was to either use journal_ioprio value specified during initial mount, or use the default value irrespective of the journal_ioprio value specified during remount. This patch modifies this to first check if a new value for ioprio has been passed during remount and apply it. If no new value is passed, use the value specified during initial mount. Signed-off-by: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx> Reviewed-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx> Tested-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220418083545.45778-1-ojaswin@xxxxxxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/super.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4394,7 +4394,8 @@ static int __ext4_fill_super(struct fs_c int silent = fc->sb_flags & SB_SILENT; /* Set defaults for the variables that will be set during parsing */ - ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO; + if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) + ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO; sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS; sbi->s_sectors_written_start = @@ -6261,7 +6262,6 @@ static int __ext4_remount(struct fs_cont char *to_free[EXT4_MAXQUOTAS]; #endif - ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO; /* Store the original options */ old_sb_flags = sb->s_flags; @@ -6287,9 +6287,14 @@ static int __ext4_remount(struct fs_cont } else old_opts.s_qf_names[i] = NULL; #endif - if (sbi->s_journal && sbi->s_journal->j_task->io_context) - ctx->journal_ioprio = - sbi->s_journal->j_task->io_context->ioprio; + if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) { + if (sbi->s_journal && sbi->s_journal->j_task->io_context) + ctx->journal_ioprio = + sbi->s_journal->j_task->io_context->ioprio; + else + ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO; + + } ext4_apply_options(fc, sb);
