1 files changed, 337 insertions, 0 deletions
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
new file mode 100644
index 000000000000..3350ab65d892
--- /dev/null
+++ b/fs/erofs/inode.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ */
+#include "xattr.h"
+
+#include <trace/events/erofs.h>
+
+/* no locking */
+static int erofs_read_inode(struct inode *inode, void *data)
+{
+	struct erofs_inode *vi = EROFS_I(inode);
+	struct erofs_inode_compact *dic = data;
+	struct erofs_inode_extended *die;
+
+	const unsigned int ifmt = le16_to_cpu(dic->i_format);
+	struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+	erofs_blk_t nblks = 0;
+
+	vi->datalayout = erofs_inode_datalayout(ifmt);
+
+	if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
+		erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
+			  vi->datalayout, vi->nid);
+		DBG_BUGON(1);
+		return -EOPNOTSUPP;
+	}
+
+	switch (erofs_inode_version(ifmt)) {
+	case EROFS_INODE_LAYOUT_EXTENDED:
+		die = data;
+
+		vi->inode_isize = sizeof(struct erofs_inode_extended);
+		vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
+
+		inode->i_mode = le16_to_cpu(die->i_mode);
+		switch (inode->i_mode & S_IFMT) {
+		case S_IFREG:
+		case S_IFDIR:
+		case S_IFLNK:
+			vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
+			break;
+		case S_IFCHR:
+		case S_IFBLK:
+			inode->i_rdev =
+				new_decode_dev(le32_to_cpu(die->i_u.rdev));
+			break;
+		case S_IFIFO:
+		case S_IFSOCK:
+			inode->i_rdev = 0;
+			break;
+		default:
+			goto bogusimode;
+		}
+		i_uid_write(inode, le32_to_cpu(die->i_uid));
+		i_gid_write(inode, le32_to_cpu(die->i_gid));
+		set_nlink(inode, le32_to_cpu(die->i_nlink));
+
+		/* ns timestamp */
+		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
+			le64_to_cpu(die->i_ctime);
+		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
+			le32_to_cpu(die->i_ctime_nsec);
+
+		inode->i_size = le64_to_cpu(die->i_size);
+
+		/* total blocks for compressed files */
+		if (erofs_inode_is_data_compressed(vi->datalayout))
+			nblks = le32_to_cpu(die->i_u.compressed_blocks);
+		break;
+	case EROFS_INODE_LAYOUT_COMPACT:
+		vi->inode_isize = sizeof(struct erofs_inode_compact);
+		vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
+
+		inode->i_mode = le16_to_cpu(dic->i_mode);
+		switch (inode->i_mode & S_IFMT) {
+		case S_IFREG:
+		case S_IFDIR:
+		case S_IFLNK:
+			vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
+			break;
+		case S_IFCHR:
+		case S_IFBLK:
+			inode->i_rdev =
+				new_decode_dev(le32_to_cpu(dic->i_u.rdev));
+			break;
+		case S_IFIFO:
+		case S_IFSOCK:
+			inode->i_rdev = 0;
+			break;
+		default:
+			goto bogusimode;
+		}
+		i_uid_write(inode, le16_to_cpu(dic->i_uid));
+		i_gid_write(inode, le16_to_cpu(dic->i_gid));
+		set_nlink(inode, le16_to_cpu(dic->i_nlink));
+
+		/* use build time to derive all file time */
+		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
+			sbi->build_time;
+		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
+			sbi->build_time_nsec;
+
+		inode->i_size = le32_to_cpu(dic->i_size);
+		if (erofs_inode_is_data_compressed(vi->datalayout))
+			nblks = le32_to_cpu(dic->i_u.compressed_blocks);
+		break;
+	default:
+		erofs_err(inode->i_sb,
+			  "unsupported on-disk inode version %u of nid %llu",
+			  erofs_inode_version(ifmt), vi->nid);
+		DBG_BUGON(1);
+		return -EOPNOTSUPP;
+	}
+
+	if (!nblks)
+		/* measure inode.i_blocks as generic filesystems */
+		inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
+	else
+		inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
+	return 0;
+
+bogusimode:
+	erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
+		  inode->i_mode, vi->nid);
+	DBG_BUGON(1);
+	return -EFSCORRUPTED;
+}
+
+static int erofs_fill_symlink(struct inode *inode, void *data,
+			      unsigned int m_pofs)
+{
+	struct erofs_inode *vi = EROFS_I(inode);
+	char *lnk;
+
+	/* if it cannot be handled with fast symlink scheme */
+	if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
+	    inode->i_size >= PAGE_SIZE) {
+		inode->i_op = &erofs_symlink_iops;
+		return 0;
+	}
+
+	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
+	if (!lnk)
+		return -ENOMEM;
+
+	m_pofs += vi->inode_isize + vi->xattr_isize;
+	/* inline symlink data shouldn't cross page boundary as well */
+	if (m_pofs + inode->i_size > PAGE_SIZE) {
+		kfree(lnk);
+		erofs_err(inode->i_sb,
+			  "inline data cross block boundary @ nid %llu",
+			  vi->nid);
+		DBG_BUGON(1);
+		return -EFSCORRUPTED;
+	}
+
+	memcpy(lnk, data + m_pofs, inode->i_size);
+	lnk[inode->i_size] = '\0';
+
+	inode->i_link = lnk;
+	inode->i_op = &erofs_fast_symlink_iops;
+	return 0;
+}
+
+static int erofs_fill_inode(struct inode *inode, int isdir)
+{
+	struct super_block *sb = inode->i_sb;
+	struct erofs_inode *vi = EROFS_I(inode);
+	struct page *page;
+	void *data;
+	int err;
+	erofs_blk_t blkaddr;
+	unsigned int ofs;
+	erofs_off_t inode_loc;
+
+	trace_erofs_fill_inode(inode, isdir);
+	inode_loc = iloc(EROFS_SB(sb), vi->nid);
+	blkaddr = erofs_blknr(inode_loc);
+	ofs = erofs_blkoff(inode_loc);
+
+	erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
+		  __func__, vi->nid, ofs, blkaddr);
+
+	page = erofs_get_meta_page(sb, blkaddr);
+
+	if (IS_ERR(page)) {
+		erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
+			  vi->nid, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	DBG_BUGON(!PageUptodate(page));
+	data = page_address(page);
+
+	err = erofs_read_inode(inode, data + ofs);
+	if (err)
+		goto out_unlock;
+
+	/* setup the new inode */
+	switch (inode->i_mode & S_IFMT) {
+	case S_IFREG:
+		inode->i_op = &erofs_generic_iops;
+		inode->i_fop = &generic_ro_fops;
+		break;
+	case S_IFDIR:
+		inode->i_op = &erofs_dir_iops;
+		inode->i_fop = &erofs_dir_fops;
+		break;
+	case S_IFLNK:
+		err = erofs_fill_symlink(inode, data, ofs);
+		if (err)
+			goto out_unlock;
+		inode_nohighmem(inode);
+		break;
+	case S_IFCHR:
+	case S_IFBLK:
+	case S_IFIFO:
+	case S_IFSOCK:
+		inode->i_op = &erofs_generic_iops;
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+		goto out_unlock;
+	default:
+		err = -EFSCORRUPTED;
+		goto out_unlock;
+	}
+
+	if (erofs_inode_is_data_compressed(vi->datalayout)) {
+		err = z_erofs_fill_inode(inode);
+		goto out_unlock;
+	}
+	inode->i_mapping->a_ops = &erofs_raw_access_aops;
+
+out_unlock:
+	unlock_page(page);
+	put_page(page);
+	return err;
+}
+
+/*
+ * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
+ * we should do more for 32-bit platform to find the right inode.
+ */
+static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
+{
+	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+
+	return EROFS_I(inode)->nid == nid;
+}
+
+static int erofs_iget_set_actor(struct inode *inode, void *opaque)
+{
+	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+
+	inode->i_ino = erofs_inode_hash(nid);
+	return 0;
+}
+
+static inline struct inode *erofs_iget_locked(struct super_block *sb,
+					      erofs_nid_t nid)
+{
+	const unsigned long hashval = erofs_inode_hash(nid);
+
+	return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
+		erofs_iget_set_actor, &nid);
+}
+
+struct inode *erofs_iget(struct super_block *sb,
+			 erofs_nid_t nid,
+			 bool isdir)
+{
+	struct inode *inode = erofs_iget_locked(sb, nid);
+
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (inode->i_state & I_NEW) {
+		int err;
+		struct erofs_inode *vi = EROFS_I(inode);
+
+		vi->nid = nid;
+
+		err = erofs_fill_inode(inode, isdir);
+		if (!err)
+			unlock_new_inode(inode);
+		else {
+			iget_failed(inode);
+			inode = ERR_PTR(err);
+		}
+	}
+	return inode;
+}
+
+int erofs_getattr(const struct path *path, struct kstat *stat,
+		  u32 request_mask, unsigned int query_flags)
+{
+	struct inode *const inode = d_inode(path->dentry);
+
+	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
+		stat->attributes |= STATX_ATTR_COMPRESSED;
+
+	stat->attributes |= STATX_ATTR_IMMUTABLE;
+	stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
+				  STATX_ATTR_IMMUTABLE);
+
+	generic_fillattr(inode, stat);
+	return 0;
+}
+
+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,
+};
+