1 files changed, 183 insertions, 98 deletions

diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 13329baeafbc..cc4dcb7a32b5 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -26,6 +26,7 @@ int __exfat_write_inode(struct inode *inode, int sync)
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 	bool is_dir = (ei->type == TYPE_DIR) ? true : false;
+	struct timespec64 ts;
 
 	if (inode->i_ino == EXFAT_ROOT_INO)
 		return 0;
@@ -55,16 +56,18 @@ int __exfat_write_inode(struct inode *inode, int sync)
 			&ep->dentry.file.create_time,
 			&ep->dentry.file.create_date,
 			&ep->dentry.file.create_time_cs);
-	exfat_set_entry_time(sbi, &inode->i_mtime,
-			&ep->dentry.file.modify_tz,
-			&ep->dentry.file.modify_time,
-			&ep->dentry.file.modify_date,
-			&ep->dentry.file.modify_time_cs);
-	exfat_set_entry_time(sbi, &inode->i_atime,
-			&ep->dentry.file.access_tz,
-			&ep->dentry.file.access_time,
-			&ep->dentry.file.access_date,
-			NULL);
+	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);
 
 	/* File size should be zero if there is no cluster allocated */
 	on_disk_size = i_size_read(inode);
@@ -72,8 +75,17 @@ int __exfat_write_inode(struct inode *inode, int sync)
 	if (ei->start_clu == EXFAT_EOF_CLUSTER)
 		on_disk_size = 0;
 
-	ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);
-	ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
+	ep2->dentry.stream.size = cpu_to_le64(on_disk_size);
+	/*
+	 * mmap write does not use exfat_write_end(), valid_size may be
+	 * extended to the sector-aligned length in exfat_get_block().
+	 * So we need to fixup valid_size to the writren length.
+	 */
+	if (on_disk_size < ei->valid_size)
+		ep2->dentry.stream.valid_size = ep2->dentry.stream.size;
+	else
+		ep2->dentry.stream.valid_size = cpu_to_le64(ei->valid_size);
+
 	if (on_disk_size) {
 		ep2->dentry.stream.flags = ei->flags;
 		ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu);
@@ -82,7 +94,7 @@ int __exfat_write_inode(struct inode *inode, int sync)
 		ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
 	}
 
-	exfat_update_dir_chksum_with_entry_set(&es);
+	exfat_update_dir_chksum(&es);
 	return exfat_put_dentry_set(&es, sync);
 }
 
@@ -90,6 +102,9 @@ 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);
@@ -118,11 +133,9 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 	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 = 0;
+	unsigned int num_to_be_allocated = 0, num_clusters;
 
-	if (ei->i_size_ondisk > 0)
-		num_clusters =
-			EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
+	num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
 
 	if (clu_offset >= num_clusters)
 		num_to_be_allocated = clu_offset - num_clusters + 1;
@@ -248,21 +261,6 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 	return 0;
 }
 
-static int exfat_map_new_buffer(struct exfat_inode_info *ei,
-		struct buffer_head *bh, loff_t pos)
-{
-	if (buffer_delay(bh) && pos > ei->i_size_aligned)
-		return -EIO;
-	set_buffer_new(bh);
-
-	/*
-	 * Adjust i_size_aligned if i_size_ondisk is bigger than it.
-	 */
-	if (ei->i_size_ondisk > ei->i_size_aligned)
-		ei->i_size_aligned = ei->i_size_ondisk;
-	return 0;
-}
-
 static int exfat_get_block(struct inode *inode, sector_t iblock,
 		struct buffer_head *bh_result, int create)
 {
@@ -275,10 +273,12 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 	unsigned int cluster, sec_offset;
 	sector_t last_block;
 	sector_t phys = 0;
-	loff_t pos;
+	sector_t valid_blks;
+	loff_t i_size;
 
 	mutex_lock(&sbi->s_lock);
-	last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);
+	i_size = i_size_read(inode);
+	last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size, sb);
 	if (iblock >= last_block && !create)
 		goto done;
 
@@ -303,31 +303,103 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 	mapped_blocks = sbi->sect_per_clus - sec_offset;
 	max_blocks = min(mapped_blocks, max_blocks);
 
-	/* Treat newly added block / cluster */
-	if (iblock < last_block)
-		create = 0;
+	map_bh(bh_result, sb, phys);
+	if (buffer_delay(bh_result))
+		clear_buffer_delay(bh_result);
+
+	/*
+	 * In most cases, we just need to set bh_result to mapped, unmapped
+	 * or new status as follows:
+	 *  1. i_size == valid_size
+	 *  2. write case (create == 1)
+	 *  3. direct_read (!bh_result->b_folio)
+	 *     -> the unwritten part will be zeroed in exfat_direct_IO()
+	 *
+	 * Otherwise, in the case of buffered read, it is necessary to take
+	 * care the last nested block if valid_size is not equal to i_size.
+	 */
+	if (i_size == ei->valid_size || create || !bh_result->b_folio)
+		valid_blks = EXFAT_B_TO_BLK_ROUND_UP(ei->valid_size, sb);
+	else
+		valid_blks = EXFAT_B_TO_BLK(ei->valid_size, sb);
 
-	if (create || buffer_delay(bh_result)) {
-		pos = EXFAT_BLK_TO_B((iblock + 1), sb);
-		if (ei->i_size_ondisk < pos)
-			ei->i_size_ondisk = pos;
+	/* The range has been fully written, map it */
+	if (iblock + max_blocks < valid_blks)
+		goto done;
+
+	/* The range has been partially written, map the written part */
+	if (iblock < valid_blks) {
+		max_blocks = valid_blks - iblock;
+		goto done;
 	}
 
+	/* The area has not been written, map and mark as new for create case */
 	if (create) {
-		err = exfat_map_new_buffer(ei, bh_result, pos);
-		if (err) {
-			exfat_fs_error(sb,
-					"requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n",
-					pos, ei->i_size_aligned);
-			goto unlock_ret;
+		set_buffer_new(bh_result);
+		ei->valid_size = EXFAT_BLK_TO_B(iblock + max_blocks, sb);
+		mark_inode_dirty(inode);
+		goto done;
+	}
+
+	/*
+	 * The area has just one block partially written.
+	 * In that case, we should read and fill the unwritten part of
+	 * a block with zero.
+	 */
+	if (bh_result->b_folio && iblock == valid_blks &&
+	    (ei->valid_size & (sb->s_blocksize - 1))) {
+		loff_t size, pos;
+		void *addr;
+
+		max_blocks = 1;
+
+		/*
+		 * No buffer_head is allocated.
+		 * (1) bmap: It's enough to set blocknr without I/O.
+		 * (2) read: The unwritten part should be filled with zero.
+		 *           If a folio does not have any buffers,
+		 *           let's returns -EAGAIN to fallback to
+		 *           block_read_full_folio() for per-bh IO.
+		 */
+		if (!folio_buffers(bh_result->b_folio)) {
+			err = -EAGAIN;
+			goto done;
 		}
+
+		pos = EXFAT_BLK_TO_B(iblock, sb);
+		size = ei->valid_size - pos;
+		addr = folio_address(bh_result->b_folio) +
+			offset_in_folio(bh_result->b_folio, pos);
+
+		/* Check if bh->b_data points to proper addr in folio */
+		if (bh_result->b_data != addr) {
+			exfat_fs_error_ratelimit(sb,
+					"b_data(%p) != folio_addr(%p)",
+					bh_result->b_data, addr);
+			err = -EINVAL;
+			goto done;
+		}
+
+		/* Read a block */
+		err = bh_read(bh_result, 0);
+		if (err < 0)
+			goto done;
+
+		/* Zero unwritten part of a block */
+		memset(bh_result->b_data + size, 0, bh_result->b_size - size);
+		err = 0;
+		goto done;
 	}
 
-	if (buffer_delay(bh_result))
-		clear_buffer_delay(bh_result);
-	map_bh(bh_result, sb, phys);
+	/*
+	 * The area has not been written, clear mapped for read/bmap cases.
+	 * If so, it will be filled with zero without reading from disk.
+	 */
+	clear_buffer_mapped(bh_result);
 done:
 	bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
+	if (err < 0)
+		clear_buffer_mapped(bh_result);
 unlock_ret:
 	mutex_unlock(&sbi->s_lock);
 	return err;
@@ -340,12 +412,26 @@ static int exfat_read_folio(struct file *file, struct folio *folio)
 
 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);
+
+	/* 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;
+
 	mpage_readahead(rac, exfat_get_block);
 }
 
 static int exfat_writepages(struct address_space *mapping,
 		struct writeback_control *wbc)
 {
+	if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
+		return -EIO;
+
 	return mpage_writepages(mapping, wbc, exfat_get_block);
 }
 
@@ -355,21 +441,21 @@ static void exfat_write_failed(struct address_space *mapping, loff_t to)
 
 	if (to > i_size_read(inode)) {
 		truncate_pagecache(inode, i_size_read(inode));
-		inode->i_mtime = inode_set_ctime_current(inode);
+		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 		exfat_truncate(inode);
 	}
 }
 
 static int exfat_write_begin(struct file *file, struct address_space *mapping,
 		loff_t pos, unsigned int len,
-		struct page **pagep, void **fsdata)
+		struct folio **foliop, void **fsdata)
 {
 	int ret;
 
-	*pagep = NULL;
-	ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
-			       exfat_get_block,
-			       &EXFAT_I(mapping->host)->i_size_ondisk);
+	if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
+		return -EIO;
+
+	ret = block_write_begin(mapping, pos, len, foliop, exfat_get_block);
 
 	if (ret < 0)
 		exfat_write_failed(mapping, pos+len);
@@ -379,27 +465,24 @@ static int exfat_write_begin(struct file *file, struct address_space *mapping,
 
 static int exfat_write_end(struct file *file, struct address_space *mapping,
 		loff_t pos, unsigned int len, unsigned int copied,
-		struct page *pagep, void *fsdata)
+		struct folio *folio, void *fsdata)
 {
 	struct inode *inode = mapping->host;
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 	int err;
 
-	err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
-
-	if (ei->i_size_aligned < i_size_read(inode)) {
-		exfat_fs_error(inode->i_sb,
-			"invalid size(size(%llu) > aligned(%llu)\n",
-			i_size_read(inode), ei->i_size_aligned);
-		return -EIO;
-	}
-
+	err = generic_write_end(file, mapping, pos, len, copied, folio, fsdata);
 	if (err < len)
 		exfat_write_failed(mapping, pos+len);
 
-	if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) {
-		inode->i_mtime = inode_set_ctime_current(inode);
-		ei->attr |= ATTR_ARCHIVE;
+	if (!(err < 0) && pos + err > ei->valid_size) {
+		ei->valid_size = pos + err;
+		mark_inode_dirty(inode);
+	}
+
+	if (!(err < 0) && !(ei->attr & EXFAT_ATTR_ARCHIVE)) {
+		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+		ei->attr |= EXFAT_ATTR_ARCHIVE;
 		mark_inode_dirty(inode);
 	}
 
@@ -410,31 +493,41 @@ static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct address_space *mapping = iocb->ki_filp->f_mapping;
 	struct inode *inode = mapping->host;
-	loff_t size = iocb->ki_pos + iov_iter_count(iter);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	loff_t pos = iocb->ki_pos;
+	loff_t size = pos + iov_iter_count(iter);
 	int rw = iov_iter_rw(iter);
 	ssize_t ret;
 
-	if (rw == WRITE) {
-		/*
-		 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
-		 * so we need to update the ->i_size_aligned to block boundary.
-		 *
-		 * But we must fill the remaining area or hole by nul for
-		 * updating ->i_size_aligned
-		 *
-		 * Return 0, and fallback to normal buffered write.
-		 */
-		if (EXFAT_I(inode)->i_size_aligned < size)
-			return 0;
-	}
-
 	/*
 	 * Need to use the DIO_LOCKING for avoiding the race
 	 * condition of exfat_get_block() and ->truncate().
 	 */
 	ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);
-	if (ret < 0 && (rw & WRITE))
-		exfat_write_failed(mapping, size);
+	if (ret < 0) {
+		if (rw == WRITE && ret != -EIOCBQUEUED)
+			exfat_write_failed(mapping, size);
+
+		return ret;
+	} else
+		size = pos + ret;
+
+	if (rw == WRITE) {
+		/*
+		 * If the block had been partially written before this write,
+		 * ->valid_size will not be updated in exfat_get_block(),
+		 * update it here.
+		 */
+		if (ei->valid_size < size) {
+			ei->valid_size = size;
+			mark_inode_dirty(inode);
+		}
+	} else if (pos < ei->valid_size && ei->valid_size < size) {
+		/* zero the unwritten part in the partially written block */
+		iov_iter_revert(iter, size - ei->valid_size);
+		iov_iter_zero(size - ei->valid_size, iter);
+	}
+
 	return ret;
 }
 
@@ -534,6 +627,7 @@ static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
 	ei->start_clu = info->start_clu;
 	ei->flags = info->flags;
 	ei->type = info->type;
+	ei->valid_size = info->valid_size;
 
 	ei->version = 0;
 	ei->hint_stat.eidx = 0;
@@ -547,7 +641,7 @@ static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
 	inode_inc_iversion(inode);
 	inode->i_generation = get_random_u32();
 
-	if (info->attr & ATTR_SUBDIR) { /* directory */
+	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;
@@ -564,22 +658,13 @@ static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
 
 	i_size_write(inode, size);
 
-	/* ondisk and aligned size should be aligned with block size */
-	if (size & (inode->i_sb->s_blocksize - 1)) {
-		size |= (inode->i_sb->s_blocksize - 1);
-		size++;
-	}
-
-	ei->i_size_aligned = size;
-	ei->i_size_ondisk = size;
-
 	exfat_save_attr(inode, info->attr);
 
 	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
-	inode->i_mtime = info->mtime;
+	inode_set_mtime_to_ts(inode, info->mtime);
 	inode_set_ctime_to_ts(inode, info->mtime);
 	ei->i_crtime = info->crtime;
-	inode->i_atime = info->atime;
+	inode_set_atime_to_ts(inode, info->atime);
 
 	return 0;
 }