ext4: fix incorrect options show of original mount_opt and extend mount_opt2

Current _ext4_show_options() do not distinguish MOPT_2 flag, so it mixed
extend sbi->s_mount_opt2 options with sbi->s_mount_opt, it could lead to
show incorrect options, e.g. show fc_debug_force if we mount with
errors=continue mode and miss it if we set.

  $ mkfs.ext4 /dev/pmem0
  $ mount -o errors=remount-ro /dev/pmem0 /mnt
  $ cat /proc/fs/ext4/pmem0/options | grep fc_debug_force
    #empty
  $ mount -o remount,errors=continue /mnt
  $ cat /proc/fs/ext4/pmem0/options | grep fc_debug_force
    fc_debug_force
  $ mount -o remount,errors=remount-ro,fc_debug_force /mnt
  $ cat /proc/fs/ext4/pmem0/options | grep fc_debug_force
    #empty

Fixes: 995a3ed67fc8 ("ext4: add fast_commit feature and handling for extended mount options")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230129034939.3702550-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 140e1eb..6479146 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1529,6 +1529,7 @@ struct ext4_sb_info {
        unsigned int s_mount_opt2;
        unsigned long s_mount_flags;
        unsigned int s_def_mount_opt;
+       unsigned int s_def_mount_opt2;
        ext4_fsblk_t s_sb_block;
        atomic64_t s_resv_clusters;
        kuid_t s_resuid;

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 143e0b5..2192b41 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2894,7 +2894,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 {
        struct ext4_sb_info *sbi = EXT4_SB(sb);
        struct ext4_super_block *es = sbi->s_es;
-       int def_errors, def_mount_opt = sbi->s_def_mount_opt;
+       int def_errors;
        const struct mount_opts *m;
        char sep = nodefs ? '\n' : ',';
 
@@ -2906,15 +2906,28 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 
        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
                int want_set = m->flags & MOPT_SET;
+               int opt_2 = m->flags & MOPT_2;
+               unsigned int mount_opt, def_mount_opt;
+
                if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
                    m->flags & MOPT_SKIP)
                        continue;
-               if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
-                       continue; /* skip if same as the default */
+
+               if (opt_2) {
+                       mount_opt = sbi->s_mount_opt2;
+                       def_mount_opt = sbi->s_def_mount_opt2;
+               } else {
+                       mount_opt = sbi->s_mount_opt;
+                       def_mount_opt = sbi->s_def_mount_opt;
+               }
+               /* skip if same as the default */
+               if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
+                       continue;
+               /* select Opt_noFoo vs Opt_Foo */
                if ((want_set &&
-                    (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
-                   (!want_set && (sbi->s_mount_opt & m->mount_opt)))
-                       continue; /* select Opt_noFoo vs Opt_Foo */
+                    (mount_opt & m->mount_opt) != m->mount_opt) ||
+                   (!want_set && (mount_opt & m->mount_opt)))
+                       continue;
                SEQ_OPTS_PRINT("%s", token2str(m->token));
        }
 
@@ -2942,7 +2955,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
        if (nodefs || sbi->s_stripe)
                SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
        if (nodefs || EXT4_MOUNT_DATA_FLAGS &
-                       (sbi->s_mount_opt ^ def_mount_opt)) {
+                       (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
                        SEQ_OPTS_PUTS("data=journal");
                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
@@ -5081,6 +5094,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
                goto failed_mount;
 
        sbi->s_def_mount_opt = sbi->s_mount_opt;
+       sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
 
        err = ext4_check_opt_consistency(fc, sb);
        if (err < 0)