udf: Limit file size to 4TB

commit c2efd13a2ed4f29bf9ef14ac2fbb7474084655f8 upstream.

UDF disk format supports in principle file sizes up to 1<<64-1. However
the file space (including holes) is described by a linked list of
extents, each of which can have at most 1GB. Thus the creation and
handling of extents gets unusably slow beyond certain point. Limit the
file size to 4TB to avoid locking up the kernel too easily.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 1939678f0b6224eb860dbef6b9bf19468be20cb0..5d79e5d2e158b75e18bc71e2a1941789cb8b276f 100644 (file)
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -86,6 +86,13 @@ enum {
 #define UDF_MAX_LVID_NESTING 1000
 
 enum { UDF_MAX_LINKS = 0xffff };
+/*
+ * We limit filesize to 4TB. This is arbitrary as the on-disk format supports
+ * more but because the file space is described by a linked list of extents,
+ * each of which can have at most 1GB, the creation and handling of extents
+ * gets unusably slow beyond certain point...
+ */
+#define UDF_MAX_FILESIZE (1ULL << 42)
 
 /* These are the "meat" - everything else is stuffing */
 static int udf_fill_super(struct super_block *, void *, int);
@@ -2301,7 +2308,7 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
                ret = -ENOMEM;
                goto error_out;
        }
-       sb->s_maxbytes = MAX_LFS_FILESIZE;
+       sb->s_maxbytes = UDF_MAX_FILESIZE;
        sb->s_max_links = UDF_MAX_LINKS;
        return 0;