Add partial support for large (>4GB) files on ext2 filesystems. This

support is partial in that it will refuse to create large files on
filesystems that haven't been upgraded to EXT2_DYN_REV or that don't
have the EXT2_FEATURE_RO_COMPAT_LARGE_FILE flag set in the superblock.

MFC after:	2 weeks

1 files changed, 10 insertions, 0 deletions

diff --git a/sys/gnu/ext2fs/ext2_inode.c b/sys/gnu/ext2fs/ext2_inode.c
index ec7215e..d940a5c 100644
--- a/sys/gnu/ext2fs/ext2_inode.c
+++ b/sys/gnu/ext2fs/ext2_inode.c
@@ -164,6 +164,16 @@ printf("ext2_truncate called %d to %d\n", VTOI(ovp)->i_number, length);
 	 * value of oszie is 0, length will be at least 1.
 	 */
 	if (osize < length) {
+		/*
+		 * XXX Refuse to extend files past 2GB on old format
+		 * filesystems or ones that don't already have the
+		 * large file flag set in the superblock.
+		 */
+		if (osize < 0x8000000 && length >= 0x80000000 &&
+		    (oip->i_e2fs->s_es->s_rev_level == EXT2_GOOD_OLD_REV ||
+		    (oip->i_e2fs->s_es->s_feature_ro_compat &
+		    EXT2_FEATURE_RO_COMPAT_LARGE_FILE) == 0))
+			return (EFBIG);
 		offset = blkoff(fs, length - 1);
 		lbn = lblkno(fs, length - 1);
 		aflags = B_CLRBUF;