libext2fs: set the large_file feature flag when setting i_size > 2GB

If someone tries to write a file that is larger than 2GB, we need to
set the large_file feature flag to affirm that i_size_hi can hold
meaningful contents.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/fileio.c b/lib/ext2fs/fileio.c
index 1f7002c..ae5cbf1 100644 (file)
--- a/lib/ext2fs/fileio.c
+++ b/lib/ext2fs/fileio.c
@@ -389,6 +389,18 @@ errcode_t ext2fs_file_set_size2(ext2_file_t file, ext2_off64_t size)
        old_truncate = ((old_size + file->fs->blocksize - 1) >>
                      EXT2_BLOCK_SIZE_BITS(file->fs->super)) + 1;
 
+       /* If we're writing a large file, set the large_file flag */
+       if (LINUX_S_ISREG(file->inode.i_mode) &&
+           EXT2_I_SIZE(&file->inode) > 0x7FFFFFFULL &&
+           (!EXT2_HAS_RO_COMPAT_FEATURE(file->fs->super,
+                                        EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
+            file->fs->super->s_rev_level == EXT2_GOOD_OLD_REV)) {
+               file->fs->super->s_feature_ro_compat |=
+                               EXT2_FEATURE_RO_COMPAT_LARGE_FILE;
+               ext2fs_update_dynamic_rev(file->fs);
+               ext2fs_mark_super_dirty(file->fs);
+       }
+
        file->inode.i_size = size & 0xffffffff;
        file->inode.i_size_high = (size >> 32);
        if (file->ino) {