[PATCH] hfsplus: limit sb_maxbytes to partition size

[Hyunchul Lee]

s_maxbytes currently is set to MAX_LFS_FILESIZE,
which allows writes beyond the partition size. As a result,
large-offset writes on small partitions can fail late
with ENOSPC.

Set s_maxbytes to the partition size.

With this change, the large-offset writes are rejected
early by `generic_write_check_limit()` with EFBIG.

This patch also fixes generic/268.

Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
---
 fs/hfsplus/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 7229a8ae89f9..18350abc659b 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -500,7 +500,8 @@ static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	/* Set up operations so we can load metadata */
 	sb->s_op = &hfsplus_sops;
-	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_maxbytes = (loff_t)min(MAX_LFS_FILESIZE,
+				     (u64)sbi->total_blocks << sbi->alloc_blksz_shift);
 
 	if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
 		pr_warn("Filesystem was not cleanly unmounted, running fsck.hfsplus is recommended.  mounting read-only.\n");
-- 
2.43.0