[PATCH] erofs-utils: lib: fix truncated uncompressed files

[Gao Xiang]

Some uncompressed files which are more than 4GiB can be truncated
incorrectly.

Fixes: 358177730598 ("erofs-utils: optimize write_uncompressed_file_from_fd()")
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
(sigh, I need to fix this issue right now as erofs-utils 1.8.1.
 and I will add a large file test for this although it may not be
 friendly for small test runners. )

 lib/inode.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/inode.c b/lib/inode.c
index b3547bf..b9dbbd6 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -515,7 +515,8 @@ static bool erofs_file_is_compressible(struct erofs_inode 
*inode)
 static int write_uncompressed_file_from_fd(struct erofs_inode *inode, int fd)
 {
        int ret;
-       unsigned int nblocks;
+       erofs_blk_t nblocks, i;
+       unsigned int len;
        struct erofs_sb_info *sbi = inode->sbi;
 
        inode->datalayout = EROFS_INODE_FLAT_INLINE;
@@ -525,12 +526,16 @@ static int write_uncompressed_file_from_fd(struct 
erofs_inode *inode, int fd)
        if (ret)
                return ret;
 
-       ret = erofs_io_xcopy(&sbi->bdev, erofs_pos(sbi, inode->u.i_blkaddr),
-                            &((struct erofs_vfile){ .fd = fd }),
-                            erofs_pos(sbi, nblocks),
+       for (i = 0; i < nblocks; i += (len >> sbi->blkszbits)) {
+               len = min_t(u64, round_down(UINT_MAX, 1U << sbi->blkszbits),
+                           erofs_pos(sbi, nblocks - i));
+               ret = erofs_io_xcopy(&sbi->bdev,
+                                    erofs_pos(sbi, inode->u.i_blkaddr + i),
+                                    &((struct erofs_vfile){ .fd = fd }), len,
                        inode->datasource == EROFS_INODE_DATA_SOURCE_DISKBUF);
-       if (ret)
-               return ret;
+               if (ret)
+                       return ret;
+       }
 
        /* read the tail-end data */
        inode->idata_size = inode->i_size % erofs_blksiz(sbi);
-- 
2.43.5