Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 611 insertions, 0 deletions

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
new file mode 100644
index 000000000..f31a08d86
--- /dev/null
+++ b/fs/erofs/super.c
@@ -0,0 +1,611 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             https://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ */
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/statfs.h>
+#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
+#include <trace/events/erofs.h>
+
+static struct kmem_cache *erofs_inode_cachep __read_mostly;
+
+void _erofs_err(struct super_block *sb, const char *function,
+		const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	pr_err("(device %s): %s: %pV", sb->s_id, function, &vaf);
+	va_end(args);
+}
+
+void _erofs_info(struct super_block *sb, const char *function,
+		 const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	pr_info("(device %s): %pV", sb->s_id, &vaf);
+	va_end(args);
+}
+
+static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata)
+{
+	struct erofs_super_block *dsb;
+	u32 expected_crc, crc;
+
+	dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET,
+		      EROFS_BLKSIZ - EROFS_SUPER_OFFSET, GFP_KERNEL);
+	if (!dsb)
+		return -ENOMEM;
+
+	expected_crc = le32_to_cpu(dsb->checksum);
+	dsb->checksum = 0;
+	/* to allow for x86 boot sectors and other oddities. */
+	crc = crc32c(~0, dsb, EROFS_BLKSIZ - EROFS_SUPER_OFFSET);
+	kfree(dsb);
+
+	if (crc != expected_crc) {
+		erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",
+			  crc, expected_crc);
+		return -EBADMSG;
+	}
+	return 0;
+}
+
+static void erofs_inode_init_once(void *ptr)
+{
+	struct erofs_inode *vi = ptr;
+
+	inode_init_once(&vi->vfs_inode);
+}
+
+static struct inode *erofs_alloc_inode(struct super_block *sb)
+{
+	struct erofs_inode *vi =
+		kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
+
+	if (!vi)
+		return NULL;
+
+	/* zero out everything except vfs_inode */
+	memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));
+	return &vi->vfs_inode;
+}
+
+static void erofs_free_inode(struct inode *inode)
+{
+	struct erofs_inode *vi = EROFS_I(inode);
+
+	/* be careful of RCU symlink path */
+	if (inode->i_op == &erofs_fast_symlink_iops)
+		kfree(inode->i_link);
+	kfree(vi->xattr_shared_xattrs);
+
+	kmem_cache_free(erofs_inode_cachep, vi);
+}
+
+static bool check_layout_compatibility(struct super_block *sb,
+				       struct erofs_super_block *dsb)
+{
+	const unsigned int feature = le32_to_cpu(dsb->feature_incompat);
+
+	EROFS_SB(sb)->feature_incompat = feature;
+
+	/* check if current kernel meets all mandatory requirements */
+	if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) {
+		erofs_err(sb,
+			  "unidentified incompatible feature %x, please upgrade kernel version",
+			   feature & ~EROFS_ALL_FEATURE_INCOMPAT);
+		return false;
+	}
+	return true;
+}
+
+static int erofs_read_superblock(struct super_block *sb)
+{
+	struct erofs_sb_info *sbi;
+	struct page *page;
+	struct erofs_super_block *dsb;
+	unsigned int blkszbits;
+	void *data;
+	int ret;
+
+	page = read_mapping_page(sb->s_bdev->bd_inode->i_mapping, 0, NULL);
+	if (IS_ERR(page)) {
+		erofs_err(sb, "cannot read erofs superblock");
+		return PTR_ERR(page);
+	}
+
+	sbi = EROFS_SB(sb);
+
+	data = kmap(page);
+	dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
+
+	ret = -EINVAL;
+	if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
+		erofs_err(sb, "cannot find valid erofs superblock");
+		goto out;
+	}
+
+	sbi->feature_compat = le32_to_cpu(dsb->feature_compat);
+	if (sbi->feature_compat & EROFS_FEATURE_COMPAT_SB_CHKSUM) {
+		ret = erofs_superblock_csum_verify(sb, data);
+		if (ret)
+			goto out;
+	}
+
+	ret = -EINVAL;
+	blkszbits = dsb->blkszbits;
+	/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
+	if (blkszbits != LOG_BLOCK_SIZE) {
+		erofs_err(sb, "blkszbits %u isn't supported on this platform",
+			  blkszbits);
+		goto out;
+	}
+
+	if (!check_layout_compatibility(sb, dsb))
+		goto out;
+
+	sbi->blocks = le32_to_cpu(dsb->blocks);
+	sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);
+#ifdef CONFIG_EROFS_FS_XATTR
+	sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);
+#endif
+	sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
+	sbi->root_nid = le16_to_cpu(dsb->root_nid);
+	sbi->inos = le64_to_cpu(dsb->inos);
+
+	sbi->build_time = le64_to_cpu(dsb->build_time);
+	sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
+
+	memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid));
+
+	ret = strscpy(sbi->volume_name, dsb->volume_name,
+		      sizeof(dsb->volume_name));
+	if (ret < 0) {	/* -E2BIG */
+		erofs_err(sb, "bad volume name without NIL terminator");
+		ret = -EFSCORRUPTED;
+		goto out;
+	}
+	ret = 0;
+out:
+	kunmap(page);
+	put_page(page);
+	return ret;
+}
+
+/* set up default EROFS parameters */
+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;
+#endif
+#ifdef CONFIG_EROFS_FS_XATTR
+	set_opt(ctx, XATTR_USER);
+#endif
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+	set_opt(ctx, POSIX_ACL);
+#endif
+}
+
+enum {
+	Opt_user_xattr,
+	Opt_acl,
+	Opt_cache_strategy,
+	Opt_err
+};
+
+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 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),
+	{}
+};
+
+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;
+
+	opt = fs_parse(fc, erofs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_user_xattr:
+#ifdef CONFIG_EROFS_FS_XATTR
+		if (result.boolean)
+			set_opt(ctx, XATTR_USER);
+		else
+			clear_opt(ctx, XATTR_USER);
+#else
+		errorfc(fc, "{,no}user_xattr options not supported");
+#endif
+		break;
+	case Opt_acl:
+#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:
+#ifdef CONFIG_EROFS_FS_ZIP
+		ctx->cache_strategy = result.uint_32;
+#else
+		errorfc(fc, "compression not supported, cache_strategy ignored");
+#endif
+		break;
+	default:
+		return -ENOPARAM;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_EROFS_FS_ZIP
+static const struct address_space_operations managed_cache_aops;
+
+static int erofs_managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
+{
+	int ret = 1;	/* 0 - busy */
+	struct address_space *const mapping = page->mapping;
+
+	DBG_BUGON(!PageLocked(page));
+	DBG_BUGON(mapping->a_ops != &managed_cache_aops);
+
+	if (PagePrivate(page))
+		ret = erofs_try_to_free_cached_page(mapping, page);
+
+	return ret;
+}
+
+static void erofs_managed_cache_invalidatepage(struct page *page,
+					       unsigned int offset,
+					       unsigned int length)
+{
+	const unsigned int stop = length + offset;
+
+	DBG_BUGON(!PageLocked(page));
+
+	/* Check for potential overflow in debug mode */
+	DBG_BUGON(stop > PAGE_SIZE || stop < length);
+
+	if (offset == 0 && stop == PAGE_SIZE)
+		while (!erofs_managed_cache_releasepage(page, GFP_NOFS))
+			cond_resched();
+}
+
+static const struct address_space_operations managed_cache_aops = {
+	.releasepage = erofs_managed_cache_releasepage,
+	.invalidatepage = erofs_managed_cache_invalidatepage,
+};
+
+static int erofs_init_managed_cache(struct super_block *sb)
+{
+	struct erofs_sb_info *const sbi = EROFS_SB(sb);
+	struct inode *const inode = new_inode(sb);
+
+	if (!inode)
+		return -ENOMEM;
+
+	set_nlink(inode, 1);
+	inode->i_size = OFFSET_MAX;
+
+	inode->i_mapping->a_ops = &managed_cache_aops;
+	mapping_set_gfp_mask(inode->i_mapping,
+			     GFP_NOFS | __GFP_HIGHMEM | __GFP_MOVABLE);
+	sbi->managed_cache = inode;
+	return 0;
+}
+#else
+static int erofs_init_managed_cache(struct super_block *sb) { return 0; }
+#endif
+
+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;
+
+	if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) {
+		erofs_err(sb, "failed to set erofs blksize");
+		return -EINVAL;
+	}
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	sb->s_fs_info = sbi;
+	err = erofs_read_superblock(sb);
+	if (err)
+		return err;
+
+	sb->s_flags |= SB_RDONLY | SB_NOATIME;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_time_gran = 1;
+
+	sb->s_op = &erofs_sops;
+	sb->s_xattr = erofs_xattr_handlers;
+
+	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
+
+	/* get the root inode */
+	inode = erofs_iget(sb, ROOT_NID(sbi), true);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	if (!S_ISDIR(inode->i_mode)) {
+		erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",
+			  ROOT_NID(sbi), inode->i_mode);
+		iput(inode);
+		return -EINVAL;
+	}
+
+	sb->s_root = d_make_root(inode);
+	if (!sb->s_root)
+		return -ENOMEM;
+
+	erofs_shrinker_register(sb);
+	/* sb->s_umount is already locked, SB_ACTIVE and SB_BORN are not set */
+	err = erofs_init_managed_cache(sb);
+	if (err)
+		return err;
+
+	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 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)
+{
+	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;
+}
+
+/*
+ * could be triggered after deactivate_locked_super()
+ * is called, thus including umount and failed to initialize.
+ */
+static void erofs_kill_sb(struct super_block *sb)
+{
+	struct erofs_sb_info *sbi;
+
+	WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
+
+	kill_block_super(sb);
+
+	sbi = EROFS_SB(sb);
+	if (!sbi)
+		return;
+	kfree(sbi);
+	sb->s_fs_info = NULL;
+}
+
+/* called when ->s_root is non-NULL */
+static void erofs_put_super(struct super_block *sb)
+{
+	struct erofs_sb_info *const sbi = EROFS_SB(sb);
+
+	DBG_BUGON(!sbi);
+
+	erofs_shrinker_unregister(sb);
+#ifdef CONFIG_EROFS_FS_ZIP
+	iput(sbi->managed_cache);
+	sbi->managed_cache = NULL;
+#endif
+}
+
+static struct file_system_type erofs_fs_type = {
+	.owner          = THIS_MODULE,
+	.name           = "erofs",
+	.init_fs_context = erofs_init_fs_context,
+	.kill_sb        = erofs_kill_sb,
+	.fs_flags       = FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("erofs");
+
+static int __init erofs_module_init(void)
+{
+	int err;
+
+	erofs_check_ondisk_layout_definitions();
+
+	erofs_inode_cachep = kmem_cache_create("erofs_inode",
+					       sizeof(struct erofs_inode), 0,
+					       SLAB_RECLAIM_ACCOUNT,
+					       erofs_inode_init_once);
+	if (!erofs_inode_cachep) {
+		err = -ENOMEM;
+		goto icache_err;
+	}
+
+	err = erofs_init_shrinker();
+	if (err)
+		goto shrinker_err;
+
+	err = z_erofs_init_zip_subsystem();
+	if (err)
+		goto zip_err;
+
+	err = register_filesystem(&erofs_fs_type);
+	if (err)
+		goto fs_err;
+
+	return 0;
+
+fs_err:
+	z_erofs_exit_zip_subsystem();
+zip_err:
+	erofs_exit_shrinker();
+shrinker_err:
+	kmem_cache_destroy(erofs_inode_cachep);
+icache_err:
+	return err;
+}
+
+static void __exit erofs_module_exit(void)
+{
+	unregister_filesystem(&erofs_fs_type);
+	z_erofs_exit_zip_subsystem();
+	erofs_exit_shrinker();
+
+	/* Ensure all RCU free inodes are safe before cache is destroyed. */
+	rcu_barrier();
+	kmem_cache_destroy(erofs_inode_cachep);
+}
+
+/* get filesystem statistics */
+static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	buf->f_type = sb->s_magic;
+	buf->f_bsize = EROFS_BLKSIZ;
+	buf->f_blocks = sbi->blocks;
+	buf->f_bfree = buf->f_bavail = 0;
+
+	buf->f_files = ULLONG_MAX;
+	buf->f_ffree = ULLONG_MAX - sbi->inos;
+
+	buf->f_namelen = EROFS_NAME_LEN;
+
+	buf->f_fsid    = u64_to_fsid(id);
+	return 0;
+}
+
+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(ctx, 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))
+		seq_puts(seq, ",acl");
+	else
+		seq_puts(seq, ",noacl");
+#endif
+#ifdef CONFIG_EROFS_FS_ZIP
+	if (ctx->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
+		seq_puts(seq, ",cache_strategy=disabled");
+	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
+		seq_puts(seq, ",cache_strategy=readahead");
+	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
+		seq_puts(seq, ",cache_strategy=readaround");
+#endif
+	return 0;
+}
+
+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,
+};
+
+module_init(erofs_module_init);
+module_exit(erofs_module_exit);
+
+MODULE_DESCRIPTION("Enhanced ROM File System");
+MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");
+MODULE_LICENSE("GPL");
+