Merge tag 'erofs-for-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs updates from Gao Xiang:
 "The most interesting part is the new mount api conversion, which is
  actually a old patch already pending for several cycles. And the
  others are recent trivial cleanups here.

  Summary:

   - Convert to use the new mount apis

   - Some random cleanup patches"

* tag 'erofs-for-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: suppress false positive last_block warning
  erofs: convert to use the new mount fs_context api
  erofs: code cleanup by removing ifdef macro surrounding

fs/erofs/data.c

@@ -265,7 +265,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio,
  */
 static int erofs_raw_access_readpage(struct file *file, struct page *page)
 {
-	erofs_off_t last_block;
+	erofs_off_t uninitialized_var(last_block);
 	struct bio *bio;
 
 	trace_erofs_readpage(page, true);
@@ -282,7 +282,7 @@ static int erofs_raw_access_readpage(struct file *file, struct page *page)
 
 static void erofs_raw_access_readahead(struct readahead_control *rac)
 {
-	erofs_off_t last_block;
+	erofs_off_t uninitialized_var(last_block);
 	struct bio *bio = NULL;
 	struct page *page;
 

fs/erofs/inode.c

@@ -311,27 +311,21 @@ int erofs_getattr(const struct path *path, struct kstat *stat,
 
 const struct inode_operations erofs_generic_iops = {
 	.getattr = erofs_getattr,
-#ifdef CONFIG_EROFS_FS_XATTR
 	.listxattr = erofs_listxattr,
-#endif
 	.get_acl = erofs_get_acl,
 };
 
 const struct inode_operations erofs_symlink_iops = {
 	.get_link = page_get_link,
 	.getattr = erofs_getattr,
-#ifdef CONFIG_EROFS_FS_XATTR
 	.listxattr = erofs_listxattr,
-#endif
 	.get_acl = erofs_get_acl,
 };
 
 const struct inode_operations erofs_fast_symlink_iops = {
 	.get_link = simple_get_link,
 	.getattr = erofs_getattr,
-#ifdef CONFIG_EROFS_FS_XATTR
 	.listxattr = erofs_listxattr,
-#endif
 	.get_acl = erofs_get_acl,
 };
 

fs/erofs/internal.h

@@ -46,6 +46,17 @@ typedef u64 erofs_off_t;
 /* data type for filesystem-wide blocks number */
 typedef u32 erofs_blk_t;
 
+struct erofs_fs_context {
+#ifdef CONFIG_EROFS_FS_ZIP
+	/* current strategy of how to use managed cache */
+	unsigned char cache_strategy;
+
+	/* threshold for decompression synchronously */
+	unsigned int max_sync_decompress_pages;
+#endif
+	unsigned int mount_opt;
+};
+
 struct erofs_sb_info {
 #ifdef CONFIG_EROFS_FS_ZIP
 	/* list for all registered superblocks, mainly for shrinker */
@@ -55,14 +66,8 @@ struct erofs_sb_info {
 	/* managed XArray arranged in physical block number */
 	struct xarray managed_pslots;
 
-	/* threshold for decompression synchronously */
-	unsigned int max_sync_decompress_pages;
-
 	unsigned int shrinker_run_no;
 
-	/* current strategy of how to use managed cache */
-	unsigned char cache_strategy;
-
 	/* pseudo inode to manage cached pages */
 	struct inode *managed_cache;
 #endif	/* CONFIG_EROFS_FS_ZIP */
@@ -88,7 +93,7 @@ struct erofs_sb_info {
 	u32 feature_compat;
 	u32 feature_incompat;
 
-	unsigned int mount_opt;
+	struct erofs_fs_context ctx;	/* options */
 };
 
 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
@@ -98,17 +103,17 @@ struct erofs_sb_info {
 #define EROFS_MOUNT_XATTR_USER		0x00000010
 #define EROFS_MOUNT_POSIX_ACL		0x00000020
 
-#define clear_opt(sbi, option)	((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
-#define set_opt(sbi, option)	((sbi)->mount_opt |= EROFS_MOUNT_##option)
-#define test_opt(sbi, option)	((sbi)->mount_opt & EROFS_MOUNT_##option)
+#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)
 
-#ifdef CONFIG_EROFS_FS_ZIP
 enum {
 	EROFS_ZIP_CACHE_DISABLED,
 	EROFS_ZIP_CACHE_READAHEAD,
 	EROFS_ZIP_CACHE_READAROUND
 };
 
+#ifdef CONFIG_EROFS_FS_ZIP
 #define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
 
 /* basic unit of the workstation of a super_block */

fs/erofs/namei.c

@@ -244,9 +244,7 @@ static struct dentry *erofs_lookup(struct inode *dir,
 const struct inode_operations erofs_dir_iops = {
 	.lookup = erofs_lookup,
 	.getattr = erofs_getattr,
-#ifdef CONFIG_EROFS_FS_XATTR
 	.listxattr = erofs_listxattr,
-#endif
 	.get_acl = erofs_get_acl,
 };
 

fs/erofs/super.c

@@ -10,6 +10,8 @@
 #include <linux/parser.h>
 #include <linux/seq_file.h>
 #include <linux/crc32c.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include "xattr.h"
 
 #define CREATE_TRACE_POINTS
@@ -192,53 +194,18 @@ static int erofs_read_superblock(struct super_block *sb)
 	return ret;
 }
 
-#ifdef CONFIG_EROFS_FS_ZIP
-static int erofs_build_cache_strategy(struct super_block *sb,
-				      substring_t *args)
-{
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-	const char *cs = match_strdup(args);
-	int err = 0;
-
-	if (!cs) {
-		erofs_err(sb, "Not enough memory to store cache strategy");
-		return -ENOMEM;
-	}
-
-	if (!strcmp(cs, "disabled")) {
-		sbi->cache_strategy = EROFS_ZIP_CACHE_DISABLED;
-	} else if (!strcmp(cs, "readahead")) {
-		sbi->cache_strategy = EROFS_ZIP_CACHE_READAHEAD;
-	} else if (!strcmp(cs, "readaround")) {
-		sbi->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
-	} else {
-		erofs_err(sb, "Unrecognized cache strategy \"%s\"", cs);
-		err = -EINVAL;
-	}
-	kfree(cs);
-	return err;
-}
-#else
-static int erofs_build_cache_strategy(struct super_block *sb,
-				      substring_t *args)
-{
-	erofs_info(sb, "EROFS compression is disabled, so cache strategy is ignored");
-	return 0;
-}
-#endif
-
 /* set up default EROFS parameters */
-static void erofs_default_options(struct erofs_sb_info *sbi)
+static void erofs_default_options(struct erofs_fs_context *ctx)
 {
 #ifdef CONFIG_EROFS_FS_ZIP
-	sbi->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
-	sbi->max_sync_decompress_pages = 3;
+	ctx->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
+	ctx->max_sync_decompress_pages = 3;
 #endif
 #ifdef CONFIG_EROFS_FS_XATTR
-	set_opt(sbi, XATTR_USER);
+	set_opt(ctx, XATTR_USER);
 #endif
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-	set_opt(sbi, POSIX_ACL);
+	set_opt(ctx, POSIX_ACL);
 #endif
 }
 
@@ -251,73 +218,62 @@ enum {
 	Opt_err
 };
 
-static match_table_t erofs_tokens = {
-	{Opt_user_xattr, "user_xattr"},
-	{Opt_nouser_xattr, "nouser_xattr"},
-	{Opt_acl, "acl"},
-	{Opt_noacl, "noacl"},
-	{Opt_cache_strategy, "cache_strategy=%s"},
-	{Opt_err, NULL}
+static const struct constant_table erofs_param_cache_strategy[] = {
+	{"disabled",	EROFS_ZIP_CACHE_DISABLED},
+	{"readahead",	EROFS_ZIP_CACHE_READAHEAD},
+	{"readaround",	EROFS_ZIP_CACHE_READAROUND},
+	{}
 };
 
-static int erofs_parse_options(struct super_block *sb, char *options)
-{
-	substring_t args[MAX_OPT_ARGS];
-	char *p;
-	int err;
-
-	if (!options)
-		return 0;
-
-	while ((p = strsep(&options, ","))) {
-		int token;
+static const struct fs_parameter_spec erofs_fs_parameters[] = {
+	fsparam_flag_no("user_xattr",	Opt_user_xattr),
+	fsparam_flag_no("acl",		Opt_acl),
+	fsparam_enum("cache_strategy",	Opt_cache_strategy,
+		     erofs_param_cache_strategy),
+	{}
+};
 
-		if (!*p)
-			continue;
+static int erofs_fc_parse_param(struct fs_context *fc,
+				struct fs_parameter *param)
+{
+	struct erofs_fs_context *ctx __maybe_unused = fc->fs_private;
+	struct fs_parse_result result;
+	int opt;
 
-		args[0].to = args[0].from = NULL;
-		token = match_token(p, erofs_tokens, args);
+	opt = fs_parse(fc, erofs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
 
-		switch (token) {
-#ifdef CONFIG_EROFS_FS_XATTR
+	switch (opt) {
 	case Opt_user_xattr:
-			set_opt(EROFS_SB(sb), XATTR_USER);
-			break;
-		case Opt_nouser_xattr:
-			clear_opt(EROFS_SB(sb), XATTR_USER);
-			break;
+#ifdef CONFIG_EROFS_FS_XATTR
+		if (result.boolean)
+			set_opt(ctx, XATTR_USER);
+		else
+			clear_opt(ctx, XATTR_USER);
 #else
-		case Opt_user_xattr:
-			erofs_info(sb, "user_xattr options not supported");
-			break;
-		case Opt_nouser_xattr:
-			erofs_info(sb, "nouser_xattr options not supported");
-			break;
+		errorfc(fc, "{,no}user_xattr options not supported");
 #endif
-#ifdef CONFIG_EROFS_FS_POSIX_ACL
-		case Opt_acl:
-			set_opt(EROFS_SB(sb), POSIX_ACL);
-			break;
-		case Opt_noacl:
-			clear_opt(EROFS_SB(sb), POSIX_ACL);
 		break;
-#else
 	case Opt_acl:
-			erofs_info(sb, "acl options not supported");
-			break;
-		case Opt_noacl:
-			erofs_info(sb, "noacl options not supported");
-			break;
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+		if (result.boolean)
+			set_opt(ctx, POSIX_ACL);
+		else
+			clear_opt(ctx, POSIX_ACL);
+#else
+		errorfc(fc, "{,no}acl options not supported");
 #endif
+		break;
 	case Opt_cache_strategy:
-			err = erofs_build_cache_strategy(sb, args);
-			if (err)
-				return err;
+#ifdef CONFIG_EROFS_FS_ZIP
+		ctx->cache_strategy = result.uint_32;
+#else
+		errorfc(fc, "compression not supported, cache_strategy ignored");
+#endif
 		break;
 	default:
-			erofs_err(sb, "Unrecognized mount option \"%s\" or missing value", p);
-			return -EINVAL;
-		}
+		return -ENOPARAM;
 	}
 	return 0;
 }
@@ -381,10 +337,11 @@ static int erofs_init_managed_cache(struct super_block *sb)
 static int erofs_init_managed_cache(struct super_block *sb) { return 0; }
 #endif
 
-static int erofs_fill_super(struct super_block *sb, void *data, int silent)
+static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct inode *inode;
 	struct erofs_sb_info *sbi;
+	struct erofs_fs_context *ctx = fc->fs_private;
 	int err;
 
 	sb->s_magic = EROFS_SUPER_MAGIC;
@@ -408,22 +365,15 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_time_gran = 1;
 
 	sb->s_op = &erofs_sops;
-
-#ifdef CONFIG_EROFS_FS_XATTR
 	sb->s_xattr = erofs_xattr_handlers;
-#endif
-	/* set erofs default mount options */
-	erofs_default_options(sbi);
-
-	err = erofs_parse_options(sb, data);
-	if (err)
-		return err;
 
-	if (test_opt(sbi, POSIX_ACL))
+	if (test_opt(ctx, 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);
 #endif
@@ -450,15 +400,58 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		return err;
 
-	erofs_info(sb, "mounted with opts: %s, root inode @ nid %llu.",
-		   (char *)data, ROOT_NID(sbi));
+	erofs_info(sb, "mounted with root inode @ nid %llu.", ROOT_NID(sbi));
+	return 0;
+}
+
+static int erofs_fc_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, erofs_fc_fill_super);
+}
+
+static int erofs_fc_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	struct erofs_fs_context *ctx = fc->fs_private;
+
+	DBG_BUGON(!sb_rdonly(sb));
+
+	if (test_opt(ctx, POSIX_ACL))
+		fc->sb_flags |= SB_POSIXACL;
+	else
+		fc->sb_flags &= ~SB_POSIXACL;
+
+	sbi->ctx = *ctx;
+
+	fc->sb_flags |= SB_RDONLY;
 	return 0;
 }
 
-static struct dentry *erofs_mount(struct file_system_type *fs_type, int flags,
-				  const char *dev_name, void *data)
+static void erofs_fc_free(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations erofs_context_ops = {
+	.parse_param	= erofs_fc_parse_param,
+	.get_tree       = erofs_fc_get_tree,
+	.reconfigure    = erofs_fc_reconfigure,
+	.free		= erofs_fc_free,
+};
+
+static int erofs_init_fs_context(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, erofs_fill_super);
+	fc->fs_private = kzalloc(sizeof(struct erofs_fs_context), GFP_KERNEL);
+	if (!fc->fs_private)
+		return -ENOMEM;
+
+	/* set default mount options */
+	erofs_default_options(fc->fs_private);
+
+	fc->ops = &erofs_context_ops;
+
+	return 0;
 }
 
 /*
@@ -497,7 +490,7 @@ static void erofs_put_super(struct super_block *sb)
 static struct file_system_type erofs_fs_type = {
 	.owner          = THIS_MODULE,
 	.name           = "erofs",
-	.mount          = erofs_mount,
+	.init_fs_context = erofs_init_fs_context,
 	.kill_sb        = erofs_kill_sb,
 	.fs_flags       = FS_REQUIRES_DEV,
 };
@@ -578,61 +571,37 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 {
 	struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb);
+	struct erofs_fs_context *ctx __maybe_unused = &sbi->ctx;
 
 #ifdef CONFIG_EROFS_FS_XATTR
-	if (test_opt(sbi, XATTR_USER))
+	if (test_opt(ctx, XATTR_USER))
 		seq_puts(seq, ",user_xattr");
 	else
 		seq_puts(seq, ",nouser_xattr");
 #endif
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-	if (test_opt(sbi, POSIX_ACL))
+	if (test_opt(ctx, POSIX_ACL))
 		seq_puts(seq, ",acl");
 	else
 		seq_puts(seq, ",noacl");
 #endif
 #ifdef CONFIG_EROFS_FS_ZIP
-	if (sbi->cache_strategy == EROFS_ZIP_CACHE_DISABLED) {
+	if (ctx->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
 		seq_puts(seq, ",cache_strategy=disabled");
-	} else if (sbi->cache_strategy == EROFS_ZIP_CACHE_READAHEAD) {
+	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
 		seq_puts(seq, ",cache_strategy=readahead");
-	} else if (sbi->cache_strategy == EROFS_ZIP_CACHE_READAROUND) {
+	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
 		seq_puts(seq, ",cache_strategy=readaround");
-	}
 #endif
 	return 0;
 }
 
-static int erofs_remount(struct super_block *sb, int *flags, char *data)
-{
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-	unsigned int org_mnt_opt = sbi->mount_opt;
-	int err;
-
-	DBG_BUGON(!sb_rdonly(sb));
-	err = erofs_parse_options(sb, data);
-	if (err)
-		goto out;
-
-	if (test_opt(sbi, POSIX_ACL))
-		sb->s_flags |= SB_POSIXACL;
-	else
-		sb->s_flags &= ~SB_POSIXACL;
-
-	*flags |= SB_RDONLY;
-	return 0;
-out:
-	sbi->mount_opt = org_mnt_opt;
-	return err;
-}
-
 const struct super_operations erofs_sops = {
 	.put_super = erofs_put_super,
 	.alloc_inode = erofs_alloc_inode,
 	.free_inode = erofs_free_inode,
 	.statfs = erofs_statfs,
 	.show_options = erofs_show_options,
-	.remount_fs = erofs_remount,
 };
 
 module_init(erofs_module_init);

fs/erofs/xattr.c

@@ -422,7 +422,7 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 
 static bool erofs_xattr_user_list(struct dentry *dentry)
 {
-	return test_opt(EROFS_SB(dentry->d_sb), XATTR_USER);
+	return test_opt(&EROFS_SB(dentry->d_sb)->ctx, XATTR_USER);
 }
 
 static bool erofs_xattr_trusted_list(struct dentry *dentry)
@@ -469,7 +469,7 @@ static int erofs_xattr_generic_get(const struct xattr_handler *handler,
 
 	switch (handler->flags) {
 	case EROFS_XATTR_INDEX_USER:
-		if (!test_opt(sbi, XATTR_USER))
+		if (!test_opt(&sbi->ctx, XATTR_USER))
 			return -EOPNOTSUPP;
 		break;
 	case EROFS_XATTR_INDEX_TRUSTED:

fs/erofs/xattr.h

@@ -76,11 +76,8 @@ static inline int erofs_getxattr(struct inode *inode, int index,
 	return -EOPNOTSUPP;
 }
 
-static inline ssize_t erofs_listxattr(struct dentry *dentry,
-				      char *buffer, size_t buffer_size)
-{
-	return -EOPNOTSUPP;
-}
+#define erofs_listxattr (NULL)
+#define erofs_xattr_handlers (NULL)
 #endif	/* !CONFIG_EROFS_FS_XATTR */
 
 #ifdef CONFIG_EROFS_FS_POSIX_ACL

fs/erofs/zdata.c

@@ -615,7 +615,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
 		goto err_out;
 
 	/* preload all compressed pages (maybe downgrade role if necessary) */
-	if (should_alloc_managed_pages(fe, sbi->cache_strategy, map->m_la))
+	if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la))
 		cache_strategy = DELAYEDALLOC;
 	else
 		cache_strategy = DONTALLOC;
@@ -1302,7 +1302,7 @@ static int z_erofs_readpage(struct file *file, struct page *page)
 static bool should_decompress_synchronously(struct erofs_sb_info *sbi,
 					    unsigned int nr)
 {
-	return nr <= sbi->max_sync_decompress_pages;
+	return nr <= sbi->ctx.max_sync_decompress_pages;
 }
 
 static void z_erofs_readahead(struct readahead_control *rac)