VisionFive2 Linux kernel

StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)

More than 9999 Commits   35 Branches   59 Tags
author: Damien Le Moal <damien.lemoal@wdc.com> 2021-03-10 15:20:28 +0900 committer: Damien Le Moal <damien.lemoal@wdc.com> 2021-03-16 17:46:55 +0900 commit: ebfd68cd0c1e81267c757332385cb96df30dacce parent: 1601ea068b886da1f8f8d4e18b9403e9e24adef6
Commit Summary:
zonefs: Fix O_APPEND async write handling
Diffstat:
1 file changed, 57 insertions, 9 deletions
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index a3d074f98660..3427c99abb4d 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -743,6 +743,68 @@ out_release:
 	return ret;
 }
 
+/*
+ * Do not exceed the LFS limits nor the file zone size. If pos is under the
+ * limit it becomes a short access. If it exceeds the limit, return -EFBIG.
+ */
+static loff_t zonefs_write_check_limits(struct file *file, loff_t pos,
+					loff_t count)
+{
+	struct inode *inode = file_inode(file);
+	struct zonefs_inode_info *zi = ZONEFS_I(inode);
+	loff_t limit = rlimit(RLIMIT_FSIZE);
+	loff_t max_size = zi->i_max_size;
+
+	if (limit != RLIM_INFINITY) {
+		if (pos >= limit) {
+			send_sig(SIGXFSZ, current, 0);
+			return -EFBIG;
+		}
+		count = min(count, limit - pos);
+	}
+
+	if (!(file->f_flags & O_LARGEFILE))
+		max_size = min_t(loff_t, MAX_NON_LFS, max_size);
+
+	if (unlikely(pos >= max_size))
+		return -EFBIG;
+
+	return min(count, max_size - pos);
+}
+
+static ssize_t zonefs_write_checks(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	struct zonefs_inode_info *zi = ZONEFS_I(inode);
+	loff_t count;
+
+	if (IS_SWAPFILE(inode))
+		return -ETXTBSY;
+
+	if (!iov_iter_count(from))
+		return 0;
+
+	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
+		return -EINVAL;
+
+	if (iocb->ki_flags & IOCB_APPEND) {
+		if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
+			return -EINVAL;
+		mutex_lock(&zi->i_truncate_mutex);
+		iocb->ki_pos = zi->i_wpoffset;
+		mutex_unlock(&zi->i_truncate_mutex);
+	}
+
+	count = zonefs_write_check_limits(file, iocb->ki_pos,
+					  iov_iter_count(from));
+	if (count < 0)
+		return count;
+
+	iov_iter_truncate(from, count);
+	return iov_iter_count(from);
+}
+
 /*
  * Handle direct writes. For sequential zone files, this is the only possible
  * write path. For these files, check that the user is issuing writes
@@ -760,8 +822,7 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
 	struct super_block *sb = inode->i_sb;
 	bool sync = is_sync_kiocb(iocb);
 	bool append = false;
-	size_t count;
-	ssize_t ret;
+	ssize_t ret, count;
 
 	/*
 	 * For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
@@ -779,12 +840,11 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
 		inode_lock(inode);
 	}
 
-	ret = generic_write_checks(iocb, from);
-	if (ret <= 0)
+	count = zonefs_write_checks(iocb, from);
+	if (count <= 0) {
+		ret = count;
 		goto inode_unlock;
-
-	iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos);
-	count = iov_iter_count(from);
+	}
 
 	if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
 		ret = -EINVAL;
@@ -844,12 +904,10 @@ static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
 		inode_lock(inode);
 	}
 
-	ret = generic_write_checks(iocb, from);
+	ret = zonefs_write_checks(iocb, from);
 	if (ret <= 0)
 		goto inode_unlock;
 
-	iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos);
-
 	ret = iomap_file_buffered_write(iocb, from, &zonefs_iomap_ops);
 	if (ret > 0)
 		iocb->ki_pos += ret;