----- Original Message -----
> LTP test case dio04 test failed on 32bit kernel running linux next
> 20191107 kernel.
> Linux version 5.4.0-rc6-next-20191107.
>
> diotest4 1 TPASS : Negative Offset
> diotest4 2 TPASS : removed
> diotest4 3 TPASS : Odd count of read and write
> diotest4 4 TPASS : Read beyond the file size
> diotest4 5 TPASS : Invalid file descriptor
> diotest4 6 TPASS : Out of range file descriptor
> diotest4 7 TPASS : Closed file descriptor
> diotest4 8 TPASS : removed
> diotest4 9 TCONF : diotest4.c:345: Direct I/O on /dev/null is
> not supported
> diotest4 10 TPASS : read, write to a mmaped file
> diotest4 11 TPASS : read, write to an unmapped file
> diotest4 12 TPASS : read from file not open for reading
> diotest4 13 TPASS : write to file not open for writing
> diotest4 14 TPASS : read, write with non-aligned buffer
> diotest4 15 TFAIL : diotest4.c:476: read to read-only space.
> returns 0: Success
> diotest4 16 TFAIL : diotest4.c:180: read, write buffer in read-only
> space
> diotest4 17 TFAIL : diotest4.c:114: read allows nonexistant
> space. returns 0: Success
> diotest4 18 TFAIL : diotest4.c:129: write allows nonexistant
> space.returns -1: Invalid argument
> diotest4 19 TFAIL : diotest4.c:180: read, write in non-existant space
> diotest4 20 TPASS : read, write for file with O_SYNC
> diotest4 0 TINFO : 2/15 test blocks failed
Smaller reproducer for 32-bit system and ext4 is:
openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4
mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000
read(4, 0xb7f7b000, 4096) = 0 // expects -EFAULT
Problem appears to be conversion in ternary operator at
iomap_dio_bio_actor() return. Test passes for me with
following tweak:
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 2f88d64c2a4d..8615b1f78389 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -318,7 +318,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
if (pad)
iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
}
- return copied ? copied : ret;
+ return copied ? (loff_t) copied : ret;
}
static loff_t
