ext4: fix i_version handling on remount

i_version mount option is getting lost on remount. This is because the
'i_version' mount option differs from the util-linux mount option
'iversion', but it has exactly the same functionality. We have to
specifically notify the vfs that this is what we want by setting
appropriate flag in fc->sb_flags. Fix it and as a result we can remove
*flags argument from __ext4_remount(); do the same for
__ext4_fill_super().

In addition set out to deprecate ext4 specific 'i_version' mount option
in favor or 'iversion' by kernel version 5.20.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Fixes: cebe85d570cf ("ext4: switch to the new mount api")
Link: https://lore.kernel.org/r/20211222104517.11187-2-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9c6cd5d..55be772 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2246,6 +2246,8 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
                ctx_set_mount_flags(ctx, EXT4_MF_FS_ABORTED);
                return 0;
        case Opt_i_version:
+               ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
+               ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
                ctx_set_flags(ctx, SB_I_VERSION);
                return 0;
        case Opt_inlinecrypt:
@@ -2875,6 +2877,14 @@ static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
        sb->s_flags &= ~ctx->mask_s_flags;
        sb->s_flags |= ctx->vals_s_flags;
 
+       /*
+        * i_version differs from common mount option iversion so we have
+        * to let vfs know that it was set, otherwise it would get cleared
+        * on remount
+        */
+       if (ctx->mask_s_flags & SB_I_VERSION)
+               fc->sb_flags |= SB_I_VERSION;
+
 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
        APPLY(s_commit_interval);
        APPLY(s_stripe);
@@ -4342,8 +4352,7 @@ err_out:
        return NULL;
 }
 
-static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb,
-                            int silent)
+static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
 {
        struct buffer_head *bh, **group_desc;
        struct ext4_super_block *es = NULL;
@@ -4363,6 +4372,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb,
        int err = 0;
        ext4_group_t first_not_zeroed;
        struct ext4_fs_context *ctx = fc->fs_private;
+       int silent = fc->sb_flags & SB_SILENT;
 
        /* Set defaults for the variables that will be set during parsing */
        ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
@@ -5540,7 +5550,7 @@ static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
        if (ctx->spec & EXT4_SPEC_s_sb_block)
                sbi->s_sb_block = ctx->s_sb_block;
 
-       ret = __ext4_fill_super(fc, sb, fc->sb_flags & SB_SILENT);
+       ret = __ext4_fill_super(fc, sb);
        if (ret < 0)
                goto free_sbi;
 
@@ -6199,13 +6209,12 @@ struct ext4_mount_options {
 #endif
 };
 
-static int __ext4_remount(struct fs_context *fc, struct super_block *sb,
-                         int *flags)
+static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
 {
        struct ext4_fs_context *ctx = fc->fs_private;
        struct ext4_super_block *es;
        struct ext4_sb_info *sbi = EXT4_SB(sb);
-       unsigned long old_sb_flags, vfs_flags;
+       unsigned long old_sb_flags;
        struct ext4_mount_options old_opts;
        ext4_group_t g;
        int err = 0;
@@ -6245,14 +6254,6 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb,
                ctx->journal_ioprio =
                        sbi->s_journal->j_task->io_context->ioprio;
 
-       /*
-        * Some options can be enabled by ext4 and/or by VFS mount flag
-        * either way we need to make sure it matches in both *flags and
-        * s_flags. Copy those selected flags from *flags to s_flags
-        */
-       vfs_flags = SB_I_VERSION;
-       sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
-
        ext4_apply_options(fc, sb);
 
        if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
@@ -6306,13 +6307,13 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb,
        /* Flush outstanding errors before changing fs state */
        flush_work(&sbi->s_error_work);
 
-       if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
+       if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
                if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
                        err = -EROFS;
                        goto restore_opts;
                }
 
-               if (*flags & SB_RDONLY) {
+               if (fc->sb_flags & SB_RDONLY) {
                        err = sync_filesystem(sb);
                        if (err < 0)
                                goto restore_opts;
@@ -6460,13 +6461,6 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb,
        if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
                ext4_stop_mmpd(sbi);
 
-       /*
-        * Some options can be enabled by ext4 and/or by VFS mount flag
-        * either way we need to make sure it matches in both *flags and
-        * s_flags. Copy those selected flags from s_flags to *flags
-        */
-       *flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
-
        return 0;
 
 restore_opts:
@@ -6498,7 +6492,6 @@ restore_opts:
 static int ext4_reconfigure(struct fs_context *fc)
 {
        struct super_block *sb = fc->root->d_sb;
-       int flags = fc->sb_flags;
        int ret;
 
        fc->s_fs_info = EXT4_SB(sb);
@@ -6507,7 +6500,7 @@ static int ext4_reconfigure(struct fs_context *fc)
        if (ret < 0)
                return ret;
 
-       ret = __ext4_remount(fc, sb, &flags);
+       ret = __ext4_remount(fc, sb);
        if (ret < 0)
                return ret;