1 files changed, 395 insertions, 0 deletions

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
new file mode 100644
index 0000000000..edc8ec7581
--- /dev/null
+++ b/fs/erofs/inode.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
+ */
+#include "xattr.h"
+
+#include <trace/events/erofs.h>
+
+static void *erofs_read_inode(struct erofs_buf *buf,
+			      struct inode *inode, unsigned int *ofs)
+{
+	struct super_block *sb = inode->i_sb;
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	struct erofs_inode *vi = EROFS_I(inode);
+	const erofs_off_t inode_loc = erofs_iloc(inode);
+
+	erofs_blk_t blkaddr, nblks = 0;
+	void *kaddr;
+	struct erofs_inode_compact *dic;
+	struct erofs_inode_extended *die, *copied = NULL;
+	unsigned int ifmt;
+	int err;
+
+	blkaddr = erofs_blknr(sb, inode_loc);
+	*ofs = erofs_blkoff(sb, inode_loc);
+
+	kaddr = erofs_read_metabuf(buf, sb, blkaddr, EROFS_KMAP);
+	if (IS_ERR(kaddr)) {
+		erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
+			  vi->nid, PTR_ERR(kaddr));
+		return kaddr;
+	}
+
+	dic = kaddr + *ofs;
+	ifmt = le16_to_cpu(dic->i_format);
+
+	if (ifmt & ~EROFS_I_ALL) {
+		erofs_err(inode->i_sb, "unsupported i_format %u of nid %llu",
+			  ifmt, vi->nid);
+		err = -EOPNOTSUPP;
+		goto err_out;
+	}
+
+	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);
+		err = -EOPNOTSUPP;
+		goto err_out;
+	}
+
+	switch (erofs_inode_version(ifmt)) {
+	case EROFS_INODE_LAYOUT_EXTENDED:
+		vi->inode_isize = sizeof(struct erofs_inode_extended);
+		/* check if the extended inode acrosses block boundary */
+		if (*ofs + vi->inode_isize <= sb->s_blocksize) {
+			*ofs += vi->inode_isize;
+			die = (struct erofs_inode_extended *)dic;
+		} else {
+			const unsigned int gotten = sb->s_blocksize - *ofs;
+
+			copied = kmalloc(vi->inode_isize, GFP_NOFS);
+			if (!copied) {
+				err = -ENOMEM;
+				goto err_out;
+			}
+			memcpy(copied, dic, gotten);
+			kaddr = erofs_read_metabuf(buf, sb, blkaddr + 1,
+						   EROFS_KMAP);
+			if (IS_ERR(kaddr)) {
+				erofs_err(sb, "failed to get inode payload block (nid: %llu), err %ld",
+					  vi->nid, PTR_ERR(kaddr));
+				kfree(copied);
+				return kaddr;
+			}
+			*ofs = vi->inode_isize - gotten;
+			memcpy((u8 *)copied + gotten, kaddr, *ofs);
+			die = copied;
+		}
+		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));
+
+		/* extended inode has its own timestamp */
+		inode_set_ctime(inode, le64_to_cpu(die->i_mtime),
+				le32_to_cpu(die->i_mtime_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);
+		else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
+			/* fill chunked inode summary info */
+			vi->chunkformat = le16_to_cpu(die->i_u.c.format);
+		kfree(copied);
+		copied = NULL;
+		break;
+	case EROFS_INODE_LAYOUT_COMPACT:
+		vi->inode_isize = sizeof(struct erofs_inode_compact);
+		*ofs += vi->inode_isize;
+		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 for compact inodes */
+		inode_set_ctime(inode, sbi->build_time, 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);
+		else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
+			vi->chunkformat = le16_to_cpu(dic->i_u.c.format);
+		break;
+	default:
+		erofs_err(inode->i_sb,
+			  "unsupported on-disk inode version %u of nid %llu",
+			  erofs_inode_version(ifmt), vi->nid);
+		err = -EOPNOTSUPP;
+		goto err_out;
+	}
+
+	if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
+		if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL) {
+			erofs_err(inode->i_sb,
+				  "unsupported chunk format %x of nid %llu",
+				  vi->chunkformat, vi->nid);
+			err = -EOPNOTSUPP;
+			goto err_out;
+		}
+		vi->chunkbits = sb->s_blocksize_bits +
+			(vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
+	}
+	inode->i_mtime = inode->i_atime = inode_get_ctime(inode);
+
+	inode->i_flags &= ~S_DAX;
+	if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
+	    (vi->datalayout == EROFS_INODE_FLAT_PLAIN ||
+	     vi->datalayout == EROFS_INODE_CHUNK_BASED))
+		inode->i_flags |= S_DAX;
+
+	if (!nblks)
+		/* measure inode.i_blocks as generic filesystems */
+		inode->i_blocks = round_up(inode->i_size, sb->s_blocksize) >> 9;
+	else
+		inode->i_blocks = nblks << (sb->s_blocksize_bits - 9);
+	return kaddr;
+
+bogusimode:
+	erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
+		  inode->i_mode, vi->nid);
+	err = -EFSCORRUPTED;
+err_out:
+	DBG_BUGON(1);
+	kfree(copied);
+	erofs_put_metabuf(buf);
+	return ERR_PTR(err);
+}
+
+static int erofs_fill_symlink(struct inode *inode, void *kaddr,
+			      unsigned int m_pofs)
+{
+	struct erofs_inode *vi = EROFS_I(inode);
+	unsigned int bsz = i_blocksize(inode);
+	char *lnk;
+
+	/* if it cannot be handled with fast symlink scheme */
+	if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
+	    inode->i_size >= bsz || inode->i_size < 0) {
+		inode->i_op = &erofs_symlink_iops;
+		return 0;
+	}
+
+	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
+	if (!lnk)
+		return -ENOMEM;
+
+	m_pofs += vi->xattr_isize;
+	/* inline symlink data shouldn't cross block boundary */
+	if (m_pofs + inode->i_size > bsz) {
+		kfree(lnk);
+		erofs_err(inode->i_sb,
+			  "inline data cross block boundary @ nid %llu",
+			  vi->nid);
+		DBG_BUGON(1);
+		return -EFSCORRUPTED;
+	}
+	memcpy(lnk, kaddr + 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)
+{
+	struct erofs_inode *vi = EROFS_I(inode);
+	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+	void *kaddr;
+	unsigned int ofs;
+	int err = 0;
+
+	trace_erofs_fill_inode(inode);
+
+	/* read inode base data from disk */
+	kaddr = erofs_read_inode(&buf, inode, &ofs);
+	if (IS_ERR(kaddr))
+		return PTR_ERR(kaddr);
+
+	/* setup the new inode */
+	switch (inode->i_mode & S_IFMT) {
+	case S_IFREG:
+		inode->i_op = &erofs_generic_iops;
+		if (erofs_inode_is_data_compressed(vi->datalayout))
+			inode->i_fop = &generic_ro_fops;
+		else
+			inode->i_fop = &erofs_file_fops;
+		break;
+	case S_IFDIR:
+		inode->i_op = &erofs_dir_iops;
+		inode->i_fop = &erofs_dir_fops;
+		inode_nohighmem(inode);
+		break;
+	case S_IFLNK:
+		err = erofs_fill_symlink(inode, kaddr, 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)) {
+#ifdef CONFIG_EROFS_FS_ZIP
+		if (!erofs_is_fscache_mode(inode->i_sb) &&
+		    inode->i_sb->s_blocksize_bits == PAGE_SHIFT) {
+			inode->i_mapping->a_ops = &z_erofs_aops;
+			err = 0;
+			goto out_unlock;
+		}
+#endif
+		err = -EOPNOTSUPP;
+		goto out_unlock;
+	}
+	inode->i_mapping->a_ops = &erofs_raw_access_aops;
+	mapping_set_large_folios(inode->i_mapping);
+#ifdef CONFIG_EROFS_FS_ONDEMAND
+	if (erofs_is_fscache_mode(inode->i_sb))
+		inode->i_mapping->a_ops = &erofs_fscache_access_aops;
+#endif
+
+out_unlock:
+	erofs_put_metabuf(&buf);
+	return err;
+}
+
+/*
+ * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
+ * so that it will fit.
+ */
+static ino_t erofs_squash_ino(erofs_nid_t nid)
+{
+	ino_t ino = (ino_t)nid;
+
+	if (sizeof(ino_t) < sizeof(erofs_nid_t))
+		ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
+	return ino;
+}
+
+static int erofs_iget5_eq(struct inode *inode, void *opaque)
+{
+	return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
+}
+
+static int erofs_iget5_set(struct inode *inode, void *opaque)
+{
+	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+
+	inode->i_ino = erofs_squash_ino(nid);
+	EROFS_I(inode)->nid = nid;
+	return 0;
+}
+
+struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
+{
+	struct inode *inode;
+
+	inode = iget5_locked(sb, erofs_squash_ino(nid), erofs_iget5_eq,
+			     erofs_iget5_set, &nid);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (inode->i_state & I_NEW) {
+		int err = erofs_fill_inode(inode);
+
+		if (err) {
+			iget_failed(inode);
+			return ERR_PTR(err);
+		}
+		unlock_new_inode(inode);
+	}
+	return inode;
+}
+
+int erofs_getattr(struct mnt_idmap *idmap, 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(idmap, request_mask, inode, stat);
+	return 0;
+}
+
+const struct inode_operations erofs_generic_iops = {
+	.getattr = erofs_getattr,
+	.listxattr = erofs_listxattr,
+	.get_inode_acl = erofs_get_acl,
+	.fiemap = erofs_fiemap,
+};
+
+const struct inode_operations erofs_symlink_iops = {
+	.get_link = page_get_link,
+	.getattr = erofs_getattr,
+	.listxattr = erofs_listxattr,
+	.get_inode_acl = erofs_get_acl,
+};
+
+const struct inode_operations erofs_fast_symlink_iops = {
+	.get_link = simple_get_link,
+	.getattr = erofs_getattr,
+	.listxattr = erofs_listxattr,
+	.get_inode_acl = erofs_get_acl,
+};