1 files changed, 459 insertions, 0 deletions

diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
new file mode 100644
index 000000000..ccd136301
--- /dev/null
+++ b/fs/exfat/inode.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/init.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/time.h>
+#include <linux/writeback.h>
+#include <linux/uio.h>
+#include <linux/random.h>
+#include <linux/iversion.h>
+#include <linux/iomap.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+#include "iomap.h"
+
+int __exfat_write_inode(struct inode *inode, int sync)
+{
+	unsigned long long on_disk_size;
+	unsigned long long on_disk_valid_size;
+	struct exfat_dentry *ep, *ep2;
+	struct exfat_entry_set_cache es;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	bool is_dir = (ei->type == TYPE_DIR);
+	struct timespec64 ts;
+
+	if (inode->i_ino == EXFAT_ROOT_INO)
+		return 0;
+
+	/*
+	 * If the inode is already unlinked, there is no need for updating it.
+	 */
+	if (ei->dir.dir == DIR_DELETED)
+		return 0;
+
+	if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1)
+		return 0;
+
+	exfat_set_volume_dirty(sb);
+
+	/* get the directory entry of given file or directory */
+	if (exfat_get_dentry_set_by_ei(&es, sb, ei))
+		return -EIO;
+	ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
+	ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
+
+	ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
+
+	/* set FILE_INFO structure using the acquired struct exfat_dentry */
+	exfat_set_entry_time(sbi, &ei->i_crtime,
+			&ep->dentry.file.create_tz,
+			&ep->dentry.file.create_time,
+			&ep->dentry.file.create_date,
+			&ep->dentry.file.create_time_cs);
+	ts = inode_get_mtime(inode);
+	exfat_set_entry_time(sbi, &ts,
+			     &ep->dentry.file.modify_tz,
+			     &ep->dentry.file.modify_time,
+			     &ep->dentry.file.modify_date,
+			     &ep->dentry.file.modify_time_cs);
+	ts = inode_get_atime(inode);
+	exfat_set_entry_time(sbi, &ts,
+			     &ep->dentry.file.access_tz,
+			     &ep->dentry.file.access_time,
+			     &ep->dentry.file.access_date,
+			     NULL);
+
+	/*
+	 * During a DIO write, valid_size is updated eagerly in iomap_end (so
+	 * that concurrent buffered reads see IOMAP_MAPPED) while i_size is
+	 * updated asynchronously in end_io.  The FAT chain was already
+	 * extended to cover ceil(valid_size/cluster_size) clusters.  Use the
+	 * maximum so the on-disk size field always covers the FAT chain,
+	 * preventing fsck from reporting "more clusters are allocated".
+	 */
+	on_disk_size = max_t(unsigned long long, i_size_read(inode),
+			ei->valid_size);
+
+	if (ei->start_clu == EXFAT_EOF_CLUSTER)
+		on_disk_size = 0;
+	/*
+	 * valid_size on disk must reflect only confirmed data (up to i_size)
+	 * and must not exceed on_disk_size.
+	 */
+	on_disk_valid_size = min_t(unsigned long long, ei->valid_size,
+			i_size_read(inode));
+	if (ei->start_clu == EXFAT_EOF_CLUSTER)
+		on_disk_valid_size = 0;
+
+	ep2->dentry.stream.size = cpu_to_le64(on_disk_size);
+	ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_valid_size);
+
+	if (on_disk_size) {
+		ep2->dentry.stream.flags = ei->flags;
+		ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu);
+	} else {
+		ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
+		ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
+	}
+
+	exfat_update_dir_chksum(&es);
+	return exfat_put_dentry_set(&es, sync);
+}
+
+int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	int ret;
+
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
+	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
+	ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
+
+	return ret;
+}
+
+void exfat_sync_inode(struct inode *inode)
+{
+	lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);
+	__exfat_write_inode(inode, 1);
+}
+
+/*
+ * Input: inode, (logical) clu_offset, target allocation area
+ * Output: errcode, cluster number
+ * *clu = (~0), if it's unable to allocate a new cluster
+ */
+int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
+		unsigned int *clu, unsigned int *count, int create,
+		bool *balloc)
+{
+	int ret;
+	unsigned int last_clu;
+	struct exfat_chain new_clu;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	unsigned int local_clu_offset = clu_offset;
+	unsigned int num_to_be_allocated = 0, num_clusters;
+
+	num_clusters = exfat_bytes_to_cluster(sbi, exfat_ondisk_size(inode));
+	if (clu_offset > num_clusters ||
+	    *count > num_clusters - clu_offset)
+		num_to_be_allocated = clu_offset + *count - num_clusters;
+
+	if (!create && (num_to_be_allocated > 0)) {
+		*clu = EXFAT_EOF_CLUSTER;
+		return 0;
+	}
+
+	*clu = last_clu = ei->start_clu;
+
+	if (*clu == EXFAT_EOF_CLUSTER) {
+		*count = 0;
+	} else if (ei->flags == ALLOC_NO_FAT_CHAIN) {
+		last_clu += num_clusters - 1;
+		if (clu_offset < num_clusters) {
+			*clu += clu_offset;
+			*count = min(num_clusters - clu_offset, *count);
+		} else {
+			*clu = EXFAT_EOF_CLUSTER;
+			*count = 0;
+		}
+	} else {
+		int err = exfat_get_cluster(inode, clu_offset,
+				clu, count, &last_clu);
+		if (err)
+			return -EIO;
+	}
+
+	if (*clu == EXFAT_EOF_CLUSTER) {
+		exfat_set_volume_dirty(sb);
+
+		new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
+				EXFAT_EOF_CLUSTER : last_clu + 1;
+		new_clu.size = 0;
+		new_clu.flags = ei->flags;
+
+		/* allocate a cluster */
+		if (num_to_be_allocated < 1) {
+			/* Broken FAT (i_sze > allocated FAT) */
+			exfat_fs_error(sb, "broken FAT chain.");
+			return -EIO;
+		}
+
+		ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu,
+				inode_needs_sync(inode), true);
+		if (ret)
+			return ret;
+
+		if (new_clu.dir == EXFAT_EOF_CLUSTER ||
+		    new_clu.dir == EXFAT_FREE_CLUSTER) {
+			exfat_fs_error(sb,
+				"bogus cluster new allocated (last_clu : %u, new_clu : %u)",
+				last_clu, new_clu.dir);
+			return -EIO;
+		}
+
+		/* append to the FAT chain */
+		if (last_clu == EXFAT_EOF_CLUSTER) {
+			if (new_clu.flags == ALLOC_FAT_CHAIN)
+				ei->flags = ALLOC_FAT_CHAIN;
+			ei->start_clu = new_clu.dir;
+		} else {
+			if (new_clu.flags != ei->flags) {
+				/* no-fat-chain bit is disabled,
+				 * so fat-chain should be synced with
+				 * alloc-bitmap
+				 */
+				if (exfat_chain_cont_cluster(sb, ei->start_clu,
+						num_clusters))
+					return -EIO;
+				ei->flags = ALLOC_FAT_CHAIN;
+			}
+			if (new_clu.flags == ALLOC_FAT_CHAIN)
+				if (exfat_ent_set(sb, last_clu, new_clu.dir))
+					return -EIO;
+		}
+
+		*clu = new_clu.dir;
+		*count = new_clu.size;
+
+		inode->i_blocks += exfat_cluster_to_sectors(sbi, new_clu.size);
+		if (balloc)
+			*balloc = true;
+	}
+
+	/* hint information */
+	ei->hint_bmap.off = local_clu_offset;
+	ei->hint_bmap.clu = *clu;
+
+	return 0;
+}
+
+static int exfat_read_folio(struct file *file, struct folio *folio)
+{
+	struct iomap_read_folio_ctx ctx = {
+		.cur_folio = folio,
+		.ops = &exfat_iomap_bio_read_ops,
+	};
+
+	iomap_read_folio(&exfat_iomap_ops, &ctx, NULL);
+	return 0;
+}
+
+static void exfat_readahead(struct readahead_control *rac)
+{
+	struct address_space *mapping = rac->mapping;
+	struct inode *inode = mapping->host;
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	loff_t pos = readahead_pos(rac);
+	struct iomap_read_folio_ctx ctx = {
+		.ops = &exfat_iomap_bio_read_ops,
+		.rac = rac,
+	};
+
+	/* Range cross valid_size, read it page by page. */
+	if (ei->valid_size < i_size_read(inode) &&
+	    pos <= ei->valid_size &&
+	    ei->valid_size < pos + readahead_length(rac))
+		return;
+
+	iomap_readahead(&exfat_iomap_ops, &ctx, NULL);
+}
+
+static int exfat_writepages(struct address_space *mapping,
+		struct writeback_control *wbc)
+{
+	struct iomap_writepage_ctx wpc = {
+		.inode		= mapping->host,
+		.wbc		= wbc,
+		.ops		= &exfat_writeback_ops,
+	};
+
+	if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
+		return -EIO;
+
+	return iomap_writepages(&wpc);
+}
+
+static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block)
+{
+	sector_t blocknr;
+
+	inode_lock_shared(mapping->host);
+	blocknr = iomap_bmap(mapping, block, &exfat_iomap_ops);
+	inode_unlock_shared(mapping->host);
+	return blocknr;
+}
+
+static const struct address_space_operations exfat_aops = {
+	.read_folio		= exfat_read_folio,
+	.readahead		= exfat_readahead,
+	.writepages		= exfat_writepages,
+	.dirty_folio		= iomap_dirty_folio,
+	.bmap			= exfat_aop_bmap,
+	.migrate_folio		= filemap_migrate_folio,
+	.is_partially_uptodate	= iomap_is_partially_uptodate,
+	.error_remove_folio	= generic_error_remove_folio,
+	.release_folio		= iomap_release_folio,
+	.invalidate_folio	= iomap_invalidate_folio,
+	.swap_activate		= exfat_iomap_swap_activate,
+};
+
+static inline unsigned long exfat_hash(loff_t i_pos)
+{
+	return hash_32(i_pos, EXFAT_HASH_BITS);
+}
+
+void exfat_hash_inode(struct inode *inode, loff_t i_pos)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+	struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
+
+	spin_lock(&sbi->inode_hash_lock);
+	EXFAT_I(inode)->i_pos = i_pos;
+	hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);
+	spin_unlock(&sbi->inode_hash_lock);
+}
+
+void exfat_unhash_inode(struct inode *inode)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+
+	spin_lock(&sbi->inode_hash_lock);
+	hlist_del_init(&EXFAT_I(inode)->i_hash_fat);
+	EXFAT_I(inode)->i_pos = 0;
+	spin_unlock(&sbi->inode_hash_lock);
+}
+
+struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *info;
+	struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
+	struct inode *inode = NULL;
+
+	spin_lock(&sbi->inode_hash_lock);
+	hlist_for_each_entry(info, head, i_hash_fat) {
+		WARN_ON(info->vfs_inode.i_sb != sb);
+
+		if (i_pos != info->i_pos)
+			continue;
+		inode = igrab(&info->vfs_inode);
+		if (inode)
+			break;
+	}
+	spin_unlock(&sbi->inode_hash_lock);
+	return inode;
+}
+
+/* doesn't deal with root inode */
+static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	loff_t size = info->size;
+
+	ei->dir = info->dir;
+	ei->entry = info->entry;
+	ei->attr = info->attr;
+	ei->start_clu = info->start_clu;
+	ei->flags = info->flags;
+	ei->type = info->type;
+	ei->valid_size = info->valid_size;
+	ei->zeroed_size = info->valid_size;
+
+	ei->version = 0;
+	ei->hint_stat.eidx = 0;
+	ei->hint_stat.clu = info->start_clu;
+	ei->hint_femp.eidx = EXFAT_HINT_NONE;
+	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
+	ei->i_pos = 0;
+
+	inode->i_uid = sbi->options.fs_uid;
+	inode->i_gid = sbi->options.fs_gid;
+	inode_inc_iversion(inode);
+	inode->i_generation = get_random_u32();
+
+	if (info->attr & EXFAT_ATTR_SUBDIR) { /* directory */
+		inode->i_generation &= ~1;
+		inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
+		inode->i_op = &exfat_dir_inode_operations;
+		inode->i_fop = &exfat_dir_operations;
+		set_nlink(inode, info->num_subdirs);
+	} else { /* regular file */
+		inode->i_generation |= 1;
+		inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
+		inode->i_op = &exfat_file_inode_operations;
+		inode->i_fop = &exfat_file_operations;
+		inode->i_mapping->a_ops = &exfat_aops;
+		inode->i_mapping->nrpages = 0;
+	}
+
+	i_size_write(inode, size);
+
+	exfat_save_attr(inode, info->attr);
+
+	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
+	inode_set_mtime_to_ts(inode, info->mtime);
+	inode_set_ctime_to_ts(inode, info->mtime);
+	ei->i_crtime = info->crtime;
+	inode_set_atime_to_ts(inode, info->atime);
+
+	return 0;
+}
+
+struct inode *exfat_build_inode(struct super_block *sb,
+		struct exfat_dir_entry *info, loff_t i_pos)
+{
+	struct inode *inode;
+	int err;
+
+	inode = exfat_iget(sb, i_pos);
+	if (inode)
+		goto out;
+	inode = new_inode(sb);
+	if (!inode) {
+		inode = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+	inode->i_ino = iunique(sb, EXFAT_ROOT_INO);
+	inode_set_iversion(inode, 1);
+	err = exfat_fill_inode(inode, info);
+	if (err) {
+		iput(inode);
+		inode = ERR_PTR(err);
+		goto out;
+	}
+	exfat_hash_inode(inode, i_pos);
+	insert_inode_hash(inode);
+out:
+	return inode;
+}
+
+void exfat_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+
+	if (!inode->i_nlink) {
+		i_size_write(inode, 0);
+		mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
+		__exfat_truncate(inode);
+		mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
+	}
+
+	clear_inode(inode);
+	exfat_cache_inval_inode(inode);
+	exfat_unhash_inode(inode);
+}