1 files changed, 371 insertions, 49 deletions

diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index 32395ef686a2..7ac5126aa4f1 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -8,45 +8,93 @@
 #include <linux/cred.h>
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>
+#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"
 
 static int exfat_cont_expand(struct inode *inode, loff_t size)
 {
-	struct address_space *mapping = inode->i_mapping;
-	loff_t start = i_size_read(inode), count = size - i_size_read(inode);
-	int err, err2;
+	int ret;
+	unsigned int num_clusters, new_num_clusters, last_clu;
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_chain clu;
 
-	err = generic_cont_expand_simple(inode, size);
-	if (err)
-		return err;
+	ret = inode_newsize_ok(inode, size);
+	if (ret)
+		return ret;
+
+	num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
+	new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
+
+	if (new_num_clusters == num_clusters)
+		goto out;
+
+	if (num_clusters) {
+		exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
+		ret = exfat_find_last_cluster(sb, &clu, &last_clu);
+		if (ret)
+			return ret;
+
+		clu.dir = last_clu + 1;
+	} else {
+		last_clu = EXFAT_EOF_CLUSTER;
+		clu.dir = EXFAT_EOF_CLUSTER;
+	}
 
-	inode->i_mtime = inode_set_ctime_current(inode);
+	clu.size = 0;
+	clu.flags = ei->flags;
+
+	ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
+			&clu, inode_needs_sync(inode));
+	if (ret)
+		return ret;
+
+	/* Append new clusters to chain */
+	if (num_clusters) {
+		if (clu.flags != ei->flags)
+			if (exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters))
+				goto free_clu;
+
+		if (clu.flags == ALLOC_FAT_CHAIN)
+			if (exfat_ent_set(sb, last_clu, clu.dir))
+				goto free_clu;
+	} else
+		ei->start_clu = clu.dir;
+
+	ei->flags = clu.flags;
+
+out:
+	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	/* Expanded range not zeroed, do not update valid_size */
+	i_size_write(inode, size);
+
+	inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
 	mark_inode_dirty(inode);
 
-	if (!IS_SYNC(inode))
-		return 0;
+	if (IS_SYNC(inode))
+		return write_inode_now(inode, 1);
 
-	err = filemap_fdatawrite_range(mapping, start, start + count - 1);
-	err2 = sync_mapping_buffers(mapping);
-	if (!err)
-		err = err2;
-	err2 = write_inode_now(inode, 1);
-	if (!err)
-		err = err2;
-	if (err)
-		return err;
+	return 0;
 
-	return filemap_fdatawait_range(mapping, start, start + count - 1);
+free_clu:
+	exfat_free_cluster(inode, &clu);
+	return -EIO;
 }
 
-static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
+static bool exfat_allow_set_time(struct mnt_idmap *idmap,
+				 struct exfat_sb_info *sbi, struct inode *inode)
 {
 	mode_t allow_utime = sbi->options.allow_utime;
 
-	if (!uid_eq(current_fsuid(), inode->i_uid)) {
-		if (in_group_p(inode->i_gid))
+	if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
+			    current_fsuid())) {
+		if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
 			allow_utime >>= 3;
 		if (allow_utime & MAY_WRITE)
 			return true;
@@ -109,7 +157,7 @@ int __exfat_truncate(struct inode *inode)
 	exfat_set_volume_dirty(sb);
 
 	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
-	num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
+	num_clusters_phys = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
 
 	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
 
@@ -143,8 +191,11 @@ 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 |= ATTR_ARCHIVE;
+		ei->attr |= EXFAT_ATTR_ARCHIVE;
 
 	/*
 	 * update the directory entry
@@ -192,8 +243,6 @@ void exfat_truncate(struct inode *inode)
 	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 blocksize = i_blocksize(inode);
-	loff_t aligned_size;
 	int err;
 
 	mutex_lock(&sbi->s_lock);
@@ -211,17 +260,6 @@ void exfat_truncate(struct inode *inode)
 
 	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
 write_size:
-	aligned_size = i_size_read(inode);
-	if (aligned_size & (blocksize - 1)) {
-		aligned_size |= (blocksize - 1);
-		aligned_size++;
-	}
-
-	if (ei->i_size_ondisk > i_size_read(inode))
-		ei->i_size_ondisk = aligned_size;
-
-	if (ei->i_size_aligned > i_size_read(inode))
-		ei->i_size_aligned = aligned_size;
 	mutex_unlock(&sbi->s_lock);
 }
 
@@ -232,7 +270,7 @@ int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
 	struct inode *inode = d_backing_inode(path->dentry);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 
-	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
+	generic_fillattr(idmap, request_mask, inode, stat);
 	exfat_truncate_atime(&stat->atime);
 	stat->result_mask |= STATX_BTIME;
 	stat->btime.tv_sec = ei->i_crtime.tv_sec;
@@ -249,6 +287,9 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	unsigned int ia_valid;
 	int error;
 
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
 	if ((attr->ia_valid & ATTR_SIZE) &&
 	    attr->ia_size > i_size_read(inode)) {
 		error = exfat_cont_expand(inode, attr->ia_size);
@@ -260,20 +301,22 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	/* Check for setting the inode time. */
 	ia_valid = attr->ia_valid;
 	if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
-	    exfat_allow_set_time(sbi, inode)) {
+	    exfat_allow_set_time(idmap, sbi, inode)) {
 		attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
 				ATTR_TIMES_SET);
 	}
 
-	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+	error = setattr_prepare(idmap, dentry, attr);
 	attr->ia_valid = ia_valid;
 	if (error)
 		goto out;
 
 	if (((attr->ia_valid & ATTR_UID) &&
-	     !uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
+	      (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
+	       sbi->options.fs_uid))) ||
 	    ((attr->ia_valid & ATTR_GID) &&
-	     !gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
+	      (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
+	       sbi->options.fs_gid))) ||
 	    ((attr->ia_valid & ATTR_MODE) &&
 	     (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
 		error = -EPERM;
@@ -290,10 +333,10 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	}
 
 	if (attr->ia_valid & ATTR_SIZE)
-		inode->i_mtime = inode_set_ctime_current(inode);
+		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 
-	setattr_copy(&nop_mnt_idmap, inode, attr);
-	exfat_truncate_atime(&inode->i_atime);
+	setattr_copy(idmap, inode, attr);
+	exfat_truncate_inode_atime(inode);
 
 	if (attr->ia_valid & ATTR_SIZE) {
 		error = exfat_block_truncate_page(inode, attr->ia_size);
@@ -316,6 +359,93 @@ out:
 	return error;
 }
 
+/*
+ * modified ioctls from fat/file.c by Welmer Almesberger
+ */
+static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
+{
+	u32 attr;
+
+	inode_lock_shared(inode);
+	attr = exfat_make_attr(inode);
+	inode_unlock_shared(inode);
+
+	return put_user(attr, user_attr);
+}
+
+static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
+{
+	struct inode *inode = file_inode(file);
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+	int is_dir = S_ISDIR(inode->i_mode);
+	u32 attr, oldattr;
+	struct iattr ia;
+	int err;
+
+	err = get_user(attr, user_attr);
+	if (err)
+		goto out;
+
+	err = mnt_want_write_file(file);
+	if (err)
+		goto out;
+	inode_lock(inode);
+
+	oldattr = exfat_make_attr(inode);
+
+	/*
+	 * Mask attributes so we don't set reserved fields.
+	 */
+	attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |
+		 EXFAT_ATTR_ARCHIVE);
+	attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);
+
+	/* Equivalent to a chmod() */
+	ia.ia_valid = ATTR_MODE | ATTR_CTIME;
+	ia.ia_ctime = current_time(inode);
+	if (is_dir)
+		ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
+	else
+		ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
+
+	/* The root directory has no attributes */
+	if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {
+		err = -EINVAL;
+		goto out_unlock_inode;
+	}
+
+	if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&
+	    !capable(CAP_LINUX_IMMUTABLE)) {
+		err = -EPERM;
+		goto out_unlock_inode;
+	}
+
+	/*
+	 * The security check is questionable...  We single
+	 * out the RO attribute for checking by the security
+	 * module, just because it maps to a file mode.
+	 */
+	err = security_inode_setattr(file_mnt_idmap(file),
+				     file->f_path.dentry, &ia);
+	if (err)
+		goto out_unlock_inode;
+
+	/* This MUST be done before doing anything irreversible... */
+	err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
+	if (err)
+		goto out_unlock_inode;
+
+	fsnotify_change(file->f_path.dentry, ia.ia_valid);
+
+	exfat_save_attr(inode, attr);
+	mark_inode_dirty(inode);
+out_unlock_inode:
+	inode_unlock(inode);
+	mnt_drop_write_file(file);
+out:
+	return err;
+}
+
 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
 {
 	struct fstrim_range range;
@@ -343,11 +473,31 @@ static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
 	return 0;
 }
 
+static int exfat_ioctl_shutdown(struct super_block *sb, unsigned long arg)
+{
+	u32 flags;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (get_user(flags, (__u32 __user *)arg))
+		return -EFAULT;
+
+	return exfat_force_shutdown(sb, flags);
+}
+
 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
+	u32 __user *user_attr = (u32 __user *)arg;
 
 	switch (cmd) {
+	case FAT_IOCTL_GET_ATTRIBUTES:
+		return exfat_ioctl_get_attributes(inode, user_attr);
+	case FAT_IOCTL_SET_ATTRIBUTES:
+		return exfat_ioctl_set_attributes(filp, user_attr);
+	case EXFAT_IOC_SHUTDOWN:
+		return exfat_ioctl_shutdown(inode->i_sb, arg);
 	case FITRIM:
 		return exfat_ioctl_fitrim(inode, arg);
 	default:
@@ -368,6 +518,9 @@ int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 	struct inode *inode = filp->f_mapping->host;
 	int err;
 
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
 	err = __generic_file_fsync(filp, start, end, datasync);
 	if (err)
 		return err;
@@ -379,17 +532,186 @@ 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_extend_valid_size(struct file *file, loff_t new_valid_size)
+{
+	int err;
+	loff_t pos;
+	struct inode *inode = file_inode(file);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct address_space *mapping = inode->i_mapping;
+	const struct address_space_operations *ops = mapping->a_ops;
+
+	pos = ei->valid_size;
+	while (pos < new_valid_size) {
+		u32 len;
+		struct folio *folio;
+		unsigned long off;
+
+		len = PAGE_SIZE - (pos & (PAGE_SIZE - 1));
+		if (pos + len > new_valid_size)
+			len = new_valid_size - pos;
+
+		err = ops->write_begin(file, mapping, pos, len, &folio, NULL);
+		if (err)
+			goto out;
+
+		off = offset_in_folio(folio, pos);
+		folio_zero_new_buffers(folio, off, off + len);
+
+		err = ops->write_end(file, mapping, pos, len, len, folio, NULL);
+		if (err < 0)
+			goto out;
+		pos += len;
+
+		balance_dirty_pages_ratelimited(mapping);
+		cond_resched();
+	}
+
+	return 0;
+
+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;
+
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
+	inode_lock(inode);
+
+	valid_size = ei->valid_size;
+
+	ret = generic_write_checks(iocb, iter);
+	if (ret <= 0)
+		goto unlock;
+
+	if (iocb->ki_flags & IOCB_DIRECT) {
+		unsigned long align = pos | iov_iter_alignment(iter);
+
+		if (!IS_ALIGNED(align, i_blocksize(inode)) &&
+		    !IS_ALIGNED(align, bdev_logical_block_size(inode->i_sb->s_bdev))) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+	}
+
+	if (pos > valid_size) {
+		ret = exfat_extend_valid_size(file, 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->ki_pos > pos) {
+		ssize_t err = generic_write_sync(iocb, iocb->ki_pos - pos);
+		if (err < 0)
+			return err;
+	}
+
+	return ret;
+
+unlock:
+	inode_unlock(inode);
+
+	return ret;
+}
+
+static ssize_t exfat_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
+	return generic_file_read_iter(iocb, iter);
+}
+
+static vm_fault_t exfat_page_mkwrite(struct vm_fault *vmf)
+{
+	int err;
+	struct vm_area_struct *vma = vmf->vma;
+	struct file *file = vma->vm_file;
+	struct inode *inode = file_inode(file);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	loff_t start, end;
+
+	if (!inode_trylock(inode))
+		return VM_FAULT_RETRY;
+
+	start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+	end = min_t(loff_t, i_size_read(inode),
+			start + vma->vm_end - vma->vm_start);
+
+	if (ei->valid_size < end) {
+		err = exfat_extend_valid_size(file, end);
+		if (err < 0) {
+			inode_unlock(inode);
+			return vmf_fs_error(err);
+		}
+	}
+
+	inode_unlock(inode);
+
+	return filemap_page_mkwrite(vmf);
+}
+
+static const struct vm_operations_struct exfat_file_vm_ops = {
+	.fault		= filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= exfat_page_mkwrite,
+};
+
+static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	if (unlikely(exfat_forced_shutdown(file_inode(file)->i_sb)))
+		return -EIO;
+
+	file_accessed(file);
+	vma->vm_ops = &exfat_file_vm_ops;
+	return 0;
+}
+
+static ssize_t exfat_splice_read(struct file *in, loff_t *ppos,
+		struct pipe_inode_info *pipe, size_t len, unsigned int flags)
+{
+	if (unlikely(exfat_forced_shutdown(file_inode(in)->i_sb)))
+		return -EIO;
+
+	return filemap_splice_read(in, ppos, pipe, len, flags);
+}
+
 const struct file_operations exfat_file_operations = {
 	.llseek		= generic_file_llseek,
-	.read_iter	= generic_file_read_iter,
-	.write_iter	= generic_file_write_iter,
+	.read_iter	= exfat_file_read_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_read	= exfat_splice_read,
 	.splice_write	= iter_file_splice_write,
 };