In stream extension directory entry, the ValidDataLength
field describes how far into the data stream user data has
been written, and the DataLength field describes the file
size.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Reviewed-by: Andy Wu <Andy.Wu@xxxxxxxx>
Reviewed-by: Aoyama Wataru <wataru.aoyama@xxxxxxxx>
---
fs/exfat/exfat_fs.h | 2 +
fs/exfat/file.c | 118 ++++++++++++++++++++++++++++++++++++++++-
fs/exfat/inode.c | 124 ++++++++++++++++++++++++++++++++++++++------
fs/exfat/namei.c | 6 +++
4 files changed, 231 insertions(+), 19 deletions(-)
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index a7a2c35d74fb..e3b1f8e022df 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -208,6 +208,7 @@ struct exfat_dir_entry {
unsigned char flags;
unsigned short attr;
loff_t size;
+ loff_t valid_size;
unsigned int num_subdirs;
struct timespec64 atime;
struct timespec64 mtime;
@@ -317,6 +318,7 @@ struct exfat_inode_info {
loff_t i_size_aligned;
/* on-disk position of directory entry or 0 */
loff_t i_pos;
+ loff_t valid_size;
/* hash by i_location */
struct hlist_node i_hash_fat;
/* protect bmap against truncate */
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index bfdfafe00993..270e2f934124 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -11,6 +11,7 @@
#include <linux/fsnotify.h>
#include <linux/security.h>
#include <linux/msdos_fs.h>
+#include <linux/writeback.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
@@ -26,6 +27,7 @@ static int exfat_cont_expand(struct inode *inode, loff_t size)
return err;
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+ EXFAT_I(inode)->valid_size = size;
mark_inode_dirty(inode);
if (!IS_SYNC(inode))
@@ -146,6 +148,9 @@ int __exfat_truncate(struct inode *inode)
ei->start_clu = EXFAT_EOF_CLUSTER;
}
+ if (i_size_read(inode) < ei->valid_size)
+ ei->valid_size = i_size_read(inode);
+
if (ei->type == TYPE_FILE)
ei->attr |= EXFAT_ATTR_ARCHIVE;
@@ -474,15 +479,124 @@ int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
return blkdev_issue_flush(inode->i_sb->s_bdev);
}
+static int exfat_file_zeroed_range(struct file *file, loff_t start, loff_t end)
+{
+ int err;
+ struct inode *inode = file_inode(file);
+ struct address_space *mapping = inode->i_mapping;
+ const struct address_space_operations *ops = mapping->a_ops;
+
+ while (start < end) {
+ u32 zerofrom, len;
+ struct page *page = NULL;
+
+ zerofrom = start & (PAGE_SIZE - 1);
+ len = PAGE_SIZE - zerofrom;
+ if (start + len > end)
+ len = end - start;
+
+ err = ops->write_begin(file, mapping, start, len, &page, NULL);
+ if (err)
+ goto out;
+
+ zero_user_segment(page, zerofrom, zerofrom + len);
+
+ err = ops->write_end(file, mapping, start, len, len, page, NULL);
+ if (err < 0)
+ goto out;
+ start += len;
+
+ balance_dirty_pages_ratelimited(mapping);
+ cond_resched();
+ }
+
+out:
+ return err;
+}
+
+static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ ssize_t ret;
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file_inode(file);
+ struct exfat_inode_info *ei = EXFAT_I(inode);
+ loff_t pos = iocb->ki_pos;
+ loff_t valid_size;
+
+ inode_lock(inode);
+
+ valid_size = ei->valid_size;
+
+ ret = generic_write_checks(iocb, iter);
+ if (ret < 0)
+ goto unlock;
+
+ if (pos > valid_size) {
+ ret = exfat_file_zeroed_range(file, valid_size, pos);
+ if (ret < 0 && ret != -ENOSPC) {
+ exfat_err(inode->i_sb,
+ "write: fail to zero from %llu to %llu(%zd)",
+ valid_size, pos, ret);
+ }
+ if (ret < 0)
+ goto unlock;
+ }
+
+ ret = __generic_file_write_iter(iocb, iter);
+ if (ret < 0)
+ goto unlock;
+
+ inode_unlock(inode);
+
+ if (pos > valid_size)
+ pos = valid_size;
+
+ if (iocb_is_dsync(iocb) && iocb->ki_pos > pos) {
+ ssize_t err = vfs_fsync_range(file, pos, iocb->ki_pos - 1,
+ iocb->ki_flags & IOCB_SYNC);
+ if (err < 0)
+ return err;
+ }
+
+ return ret;
+
+unlock:
+ inode_unlock(inode);
+
+ return ret;
+}
+
+static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int ret;
+ struct inode *inode = file_inode(file);
+ struct exfat_inode_info *ei = EXFAT_I(inode);
+ loff_t start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+ loff_t end = min_t(loff_t, i_size_read(inode),
+ start + vma->vm_end - vma->vm_start);
+
+ if ((vma->vm_flags & VM_WRITE) && ei->valid_size < end) {
+ ret = exfat_file_zeroed_range(file, ei->valid_size, end);
+ if (ret < 0) {
+ exfat_err(inode->i_sb,
+ "mmap: fail to zero from %llu to %llu(%d)",
+ start, end, ret);
+ return ret;
+ }
+ }
+
+ return generic_file_mmap(file, vma);
+}
+
const struct file_operations exfat_file_operations = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
- .write_iter = generic_file_write_iter,
+ .write_iter = exfat_file_write_iter,
.unlocked_ioctl = exfat_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = exfat_compat_ioctl,
#endif
- .mmap = generic_file_mmap,
+ .mmap = exfat_file_mmap,
.fsync = exfat_file_fsync,
.splice_read = filemap_splice_read,
.splice_write = iter_file_splice_write,
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index e7ff58b8e68c..b02677c9fd45 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -75,8 +75,8 @@ 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.valid_size = cpu_to_le64(ei->valid_size);
+ ep2->dentry.stream.size = cpu_to_le64(on_disk_size);
if (on_disk_size) {
ep2->dentry.stream.flags = ei->flags;
ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu);
@@ -278,6 +278,7 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
unsigned int cluster, sec_offset;
sector_t last_block;
sector_t phys = 0;
+ sector_t valid_blks;
loff_t pos;
mutex_lock(&sbi->s_lock);
@@ -306,17 +307,32 @@ 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;
-
- if (create || buffer_delay(bh_result)) {
- pos = EXFAT_BLK_TO_B((iblock + 1), sb);
+ pos = EXFAT_BLK_TO_B((iblock + 1), sb);
+ if ((create && iblock >= last_block) || buffer_delay(bh_result)) {
if (ei->i_size_ondisk < pos)
ei->i_size_ondisk = pos;
}
+ map_bh(bh_result, sb, phys);
+ if (buffer_delay(bh_result))
+ clear_buffer_delay(bh_result);
+
if (create) {
+ valid_blks = EXFAT_B_TO_BLK_ROUND_UP(ei->valid_size, sb);
+
+ if (iblock + max_blocks < valid_blks) {
+ /* The range has been written, map it */
+ goto done;
+ } else if (iblock < valid_blks) {
+ /*
+ * The range has been partially written,
+ * map the written part.
+ */
+ max_blocks = valid_blks - iblock;
+ goto done;
+ }
+
+ /* The area has not been written, map and mark as new. */
err = exfat_map_new_buffer(ei, bh_result, pos);
if (err) {
exfat_fs_error(sb,
@@ -324,11 +340,55 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
pos, ei->i_size_aligned);
goto unlock_ret;
}
+ } else {
+ valid_blks = EXFAT_B_TO_BLK(ei->valid_size, sb);
+
+ if (iblock + max_blocks < valid_blks) {
+ /* The range has been written, map it */
+ goto done;
+ } else if (iblock < valid_blks) {
+ /*
+ * The area has been partially written,
+ * map the written part.
+ */
+ max_blocks = valid_blks - iblock;
+ goto done;
+ } else if (iblock == valid_blks &&
+ (ei->valid_size & (sb->s_blocksize - 1))) {
+ /*
+ * The block has been partially written,
+ * zero the unwritten part and map the block.
+ */
+ loff_t size, off;
+
+ max_blocks = 1;
+
+ /*
+ * For direct read, the unwritten part will be zeroed in
+ * exfat_direct_IO()
+ */
+ if (!bh_result->b_folio)
+ goto done;
+
+ pos -= sb->s_blocksize;
+ size = ei->valid_size - pos;
+ off = pos & (PAGE_SIZE - 1);
+
+ folio_set_bh(bh_result, bh_result->b_folio, off);
+ err = bh_read(bh_result, 0);
+ if (err < 0)
+ goto unlock_ret;
+
+ folio_zero_segment(bh_result->b_folio, off + size,
+ off + sb->s_blocksize);
+ } else {
+ /*
+ * The range has not been written, clear the mapped flag
+ * to only zero the cache and do not read from disk.
+ */
+ clear_buffer_mapped(bh_result);
+ }
}
-
- if (buffer_delay(bh_result))
- clear_buffer_delay(bh_result);
- map_bh(bh_result, sb, phys);
done:
bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
unlock_ret:
@@ -343,6 +403,17 @@ 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);
}
@@ -370,9 +441,7 @@ static int exfat_write_begin(struct file *file, struct address_space *mapping,
int ret;
*pagep = NULL;
- ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
- exfat_get_block,
- &EXFAT_I(mapping->host)->i_size_ondisk);
+ ret = block_write_begin(mapping, pos, len, pagep, exfat_get_block);
if (ret < 0)
exfat_write_failed(mapping, pos+len);
@@ -400,6 +469,11 @@ static int exfat_write_end(struct file *file, struct address_space *mapping,
if (err < len)
exfat_write_failed(mapping, pos+len);
+ 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;
@@ -413,6 +487,8 @@ 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;
+ struct exfat_inode_info *ei = EXFAT_I(inode);
+ loff_t pos = iocb->ki_pos;
loff_t size = iocb->ki_pos + iov_iter_count(iter);
int rw = iov_iter_rw(iter);
ssize_t ret;
@@ -436,8 +512,21 @@ static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
* 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)
+ exfat_write_failed(mapping, size);
+
+ if (ret != -EIOCBQUEUED)
+ return ret;
+ } else
+ size = pos + ret;
+
+ /* zero the unwritten part in the partially written block */
+ if (rw == READ && pos < ei->valid_size && ei->valid_size < size) {
+ iov_iter_revert(iter, size - ei->valid_size);
+ iov_iter_zero(size - ei->valid_size, iter);
+ }
+
return ret;
}
@@ -537,6 +626,7 @@ 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;
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 5d737e0b639a..9c549fd11fc8 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -406,6 +406,7 @@ static int exfat_find_empty_entry(struct inode *inode,
i_size_write(inode, size);
ei->i_size_ondisk += sbi->cluster_size;
ei->i_size_aligned += sbi->cluster_size;
+ ei->valid_size += sbi->cluster_size;
ei->flags = p_dir->flags;
inode->i_blocks += sbi->cluster_size >> 9;
}
@@ -558,6 +559,8 @@ static int exfat_add_entry(struct inode *inode, const char *path,
info->size = clu_size;
info->num_subdirs = EXFAT_MIN_SUBDIR;
}
+ info->valid_size = info->size;
+
memset(&info->crtime, 0, sizeof(info->crtime));
memset(&info->mtime, 0, sizeof(info->mtime));
memset(&info->atime, 0, sizeof(info->atime));
@@ -660,6 +663,8 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
info->type = exfat_get_entry_type(ep);
info->attr = le16_to_cpu(ep->dentry.file.attr);
info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
+ info->valid_size = le64_to_cpu(ep2->dentry.stream.valid_size);
+ info->size = le64_to_cpu(ep2->dentry.stream.size);
if (info->size == 0) {
info->flags = ALLOC_NO_FAT_CHAIN;
info->start_clu = EXFAT_EOF_CLUSTER;
@@ -1288,6 +1293,7 @@ static int __exfat_rename(struct inode *old_parent_inode,
}
i_size_write(new_inode, 0);
+ new_ei->valid_size = 0;
new_ei->start_clu = EXFAT_EOF_CLUSTER;
new_ei->flags = ALLOC_NO_FAT_CHAIN;
}
--
2.25.1
