[add the other iomap maintainer to cc] [add the ext4 list to cc since they just added iomap directio support] [add the ext4 maintainer for the same reason] On Thu, Nov 07, 2019 at 07:20:43PM -0500, Jan Stancek wrote: > > > ----- 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: I can't do a whole lot with a code snippet that lacks a proper SOB header. > 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; I'm a little confused on this proposed fix -- why does casting size_t (aka unsigned long) to loff_t (long long) on a 32-bit system change the test outcome? Does this same diotest4 failure happen with XFS? I ask because XFS has been using iomap for directio for ages. AFAICT @copied is a simple byte counter, and the other variable @n that gets added to @copied is also a simple byte counter -- nobody should ever be trying to stuff a negative value in there? (Or is this a bug with the ext4 code that calls iomap_dio_rw?) --D > } > > static loff_t >
