[PATCH 07/31] libext2fs: When writing a file that has a i_size > 2GB, set the large_file feature flag and update the superblock.

Darrick J. Wong
2013-10-01T01:27:33Z

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.
(I don't see anything checking large_file except e2fsck...)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
lib/ext2fs/fileio.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/lib/ext2fs/fileio.c b/lib/ext2fs/fileio.c
index 1f7002c..ae5cbf1 100644
--- 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) {