erofs: decouple basic mount options from fs_context

Previously, EROFS mount options are all in the basic types, so
erofs_fs_context can be directly copied with assignment. However,
when the multiple device feature is introduced, it's hard to handle
multiple device information like the other basic mount options.

Let's separate basic mount option usage from fs_context, thus
multiple device information can be handled gracefully then.

No logic changes.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Chao Yu <[e-mail]>
Reviewed-by: Liu Bo <[e-mail]>
Signed-off-by: Gao Xiang <[e-mail]>

fs/erofs/inode.c

···
 	inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
 
 	inode->i_flags &= ~S_DAX;
-	if (test_opt(&sbi->ctx, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
+	if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
 	    vi->datalayout == EROFS_INODE_FLAT_PLAIN)
 		inode->i_flags |= S_DAX;
 	if (!nblks)

fs/erofs/internal.h

···
 /* data type for filesystem-wide blocks number */
 typedef u32 erofs_blk_t;
 
-struct erofs_fs_context {
+struct erofs_mount_opts {
 #ifdef CONFIG_EROFS_FS_ZIP
 	/* current strategy of how to use managed cache */
 	unsigned char cache_strategy;
···
 	unsigned int mount_opt;
 };
 
+struct erofs_fs_context {
+	struct erofs_mount_opts opt;
+};
+
 /* all filesystem-wide lz4 configurations */
 struct erofs_sb_lz4_info {
 	/* # of pages needed for EROFS lz4 rolling decompression */
···
 };
 
 struct erofs_sb_info {
+	struct erofs_mount_opts opt;	/* options */
+
 #ifdef CONFIG_EROFS_FS_ZIP
 	/* list for all registered superblocks, mainly for shrinker */
 	struct list_head list;
···
 	u8 volume_name[16];             /* volume name */
 	u32 feature_compat;
 	u32 feature_incompat;
-
-	struct erofs_fs_context ctx;	/* options */
 };
 
 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
···
 #define EROFS_MOUNT_DAX_ALWAYS		0x00000040
 #define EROFS_MOUNT_DAX_NEVER		0x00000080
 
-#define clear_opt(ctx, option)	((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
-#define set_opt(ctx, option)	((ctx)->mount_opt |= EROFS_MOUNT_##option)
-#define test_opt(ctx, option)	((ctx)->mount_opt & EROFS_MOUNT_##option)
+#define clear_opt(opt, option)	((opt)->mount_opt &= ~EROFS_MOUNT_##option)
+#define set_opt(opt, option)	((opt)->mount_opt |= EROFS_MOUNT_##option)
+#define test_opt(opt, option)	((opt)->mount_opt & EROFS_MOUNT_##option)
 
 enum {
 	EROFS_ZIP_CACHE_DISABLED,

fs/erofs/super.c

···
 static void erofs_default_options(struct erofs_fs_context *ctx)
 {
 #ifdef CONFIG_EROFS_FS_ZIP
-	ctx->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
-	ctx->max_sync_decompress_pages = 3;
-	ctx->readahead_sync_decompress = false;
+	ctx->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND;
+	ctx->opt.max_sync_decompress_pages = 3;
+	ctx->opt.readahead_sync_decompress = false;
 #endif
 #ifdef CONFIG_EROFS_FS_XATTR
-	set_opt(ctx, XATTR_USER);
+	set_opt(&ctx->opt, XATTR_USER);
 #endif
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-	set_opt(ctx, POSIX_ACL);
+	set_opt(&ctx->opt, POSIX_ACL);
 #endif
 }
 
···
 	switch (mode) {
 	case EROFS_MOUNT_DAX_ALWAYS:
 		warnfc(fc, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
-		set_opt(ctx, DAX_ALWAYS);
-		clear_opt(ctx, DAX_NEVER);
+		set_opt(&ctx->opt, DAX_ALWAYS);
+		clear_opt(&ctx->opt, DAX_NEVER);
 		return true;
 	case EROFS_MOUNT_DAX_NEVER:
-		set_opt(ctx, DAX_NEVER);
-		clear_opt(ctx, DAX_ALWAYS);
+		set_opt(&ctx->opt, DAX_NEVER);
+		clear_opt(&ctx->opt, DAX_ALWAYS);
 		return true;
 	default:
 		DBG_BUGON(1);
···
 	case Opt_user_xattr:
 #ifdef CONFIG_EROFS_FS_XATTR
 		if (result.boolean)
-			set_opt(ctx, XATTR_USER);
+			set_opt(&ctx->opt, XATTR_USER);
 		else
-			clear_opt(ctx, XATTR_USER);
+			clear_opt(&ctx->opt, XATTR_USER);
 #else
 		errorfc(fc, "{,no}user_xattr options not supported");
 #endif
···
 	case Opt_acl:
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
 		if (result.boolean)
-			set_opt(ctx, POSIX_ACL);
+			set_opt(&ctx->opt, POSIX_ACL);
 		else
-			clear_opt(ctx, POSIX_ACL);
+			clear_opt(&ctx->opt, POSIX_ACL);
 #else
 		errorfc(fc, "{,no}acl options not supported");
 #endif
 		break;
 	case Opt_cache_strategy:
 #ifdef CONFIG_EROFS_FS_ZIP
-		ctx->cache_strategy = result.uint_32;
+		ctx->opt.cache_strategy = result.uint_32;
 #else
 		errorfc(fc, "compression not supported, cache_strategy ignored");
 #endif
···
 		return -ENOMEM;
 
 	sb->s_fs_info = sbi;
+	sbi->opt = ctx->opt;
 	sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 	err = erofs_read_superblock(sb);
 	if (err)
 		return err;
 
-	if (test_opt(ctx, DAX_ALWAYS) &&
+	if (test_opt(&sbi->opt, DAX_ALWAYS) &&
 	    !dax_supported(sbi->dax_dev, sb->s_bdev, EROFS_BLKSIZ, 0, bdev_nr_sectors(sb->s_bdev))) {
 		errorfc(fc, "DAX unsupported by block device. Turning off DAX.");
-		clear_opt(ctx, DAX_ALWAYS);
+		clear_opt(&sbi->opt, DAX_ALWAYS);
 	}
 	sb->s_flags |= SB_RDONLY | SB_NOATIME;
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
···
 	sb->s_op = &erofs_sops;
 	sb->s_xattr = erofs_xattr_handlers;
 
-	if (test_opt(ctx, POSIX_ACL))
+	if (test_opt(&sbi->opt, POSIX_ACL))
 		sb->s_flags |= SB_POSIXACL;
 	else
 		sb->s_flags &= ~SB_POSIXACL;
-
-	sbi->ctx = *ctx;
 
 #ifdef CONFIG_EROFS_FS_ZIP
 	xa_init(&sbi->managed_pslots);
···
 
 	DBG_BUGON(!sb_rdonly(sb));
 
-	if (test_opt(ctx, POSIX_ACL))
+	if (test_opt(&ctx->opt, POSIX_ACL))
 		fc->sb_flags |= SB_POSIXACL;
 	else
 		fc->sb_flags &= ~SB_POSIXACL;
 
-	sbi->ctx = *ctx;
+	sbi->opt = ctx->opt;
 
 	fc->sb_flags |= SB_RDONLY;
 	return 0;
···
 	erofs_default_options(fc->fs_private);
 
 	fc->ops = &erofs_context_ops;
-
 	return 0;
 }
 
···
 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 {
 	struct erofs_sb_info *sbi = EROFS_SB(root->d_sb);
-	struct erofs_fs_context *ctx = &sbi->ctx;
+	struct erofs_mount_opts *opt = &sbi->opt;
 
 #ifdef CONFIG_EROFS_FS_XATTR
-	if (test_opt(ctx, XATTR_USER))
+	if (test_opt(opt, XATTR_USER))
 		seq_puts(seq, ",user_xattr");
 	else
 		seq_puts(seq, ",nouser_xattr");
 #endif
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-	if (test_opt(ctx, POSIX_ACL))
+	if (test_opt(opt, POSIX_ACL))
 		seq_puts(seq, ",acl");
 	else
 		seq_puts(seq, ",noacl");
 #endif
 #ifdef CONFIG_EROFS_FS_ZIP
-	if (ctx->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
+	if (opt->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
 		seq_puts(seq, ",cache_strategy=disabled");
-	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
+	else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
 		seq_puts(seq, ",cache_strategy=readahead");
-	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
+	else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
 		seq_puts(seq, ",cache_strategy=readaround");
 #endif
-	if (test_opt(ctx, DAX_ALWAYS))
+	if (test_opt(opt, DAX_ALWAYS))
 		seq_puts(seq, ",dax=always");
-	if (test_opt(ctx, DAX_NEVER))
+	if (test_opt(opt, DAX_NEVER))
 		seq_puts(seq, ",dax=never");
 	return 0;
 }

fs/erofs/xattr.c

···
 
 static bool erofs_xattr_user_list(struct dentry *dentry)
 {
-	return test_opt(&EROFS_SB(dentry->d_sb)->ctx, XATTR_USER);
+	return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER);
 }
 
 static bool erofs_xattr_trusted_list(struct dentry *dentry)
···
 
 	switch (handler->flags) {
 	case EROFS_XATTR_INDEX_USER:
-		if (!test_opt(&sbi->ctx, XATTR_USER))
+		if (!test_opt(&sbi->opt, XATTR_USER))
 			return -EOPNOTSUPP;
 		break;
 	case EROFS_XATTR_INDEX_TRUSTED:

fs/erofs/zdata.c

···
 		goto err_out;
 
 	/* preload all compressed pages (maybe downgrade role if necessary) */
-	if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la))
+	if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy, map->m_la))
 		cache_strategy = TRYALLOC;
 	else
 		cache_strategy = DONTALLOC;
···
 	/* Use workqueue and sync decompression for atomic contexts only */
 	if (in_atomic() || irqs_disabled()) {
 		queue_work(z_erofs_workqueue, &io->u.work);
-		sbi->ctx.readahead_sync_decompress = true;
+		sbi->opt.readahead_sync_decompress = true;
 		return;
 	}
 	z_erofs_decompressqueue_work(&io->u.work);
···
 	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
 
 	unsigned int nr_pages = readahead_count(rac);
-	bool sync = (sbi->ctx.readahead_sync_decompress &&
-			nr_pages <= sbi->ctx.max_sync_decompress_pages);
+	bool sync = (sbi->opt.readahead_sync_decompress &&
+			nr_pages <= sbi->opt.max_sync_decompress_pages);
 	struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
 	struct page *page, *head = NULL;
 	LIST_HEAD(pagepool);