Don break too early in readwrite mode

Don break too early in readwrite mode

In readwrite mode, when io-size > size, we break too early and start
looping the addresses too soon. Instead of reset the address when
reaching size, we start looping after size/2, e.g. in a 50/50 rw. This
wrong behavior is demonstrated in the example below.

Before the fix:
size is 0x140000, io-size is 0x280000, max-address = 0xa0000 = size / 2.

./fio --debug=io --name=global --filename=/dev/mmcblk0p3 --size=1280K
--io_size=2560k --bs=128K --offset=0   --name=test1 --rw=rw| grep "complete: io_u"

io 5646 complete: io_u 0x560337a20840: off=0x60000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x80000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x20000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x40000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x60000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0xa0000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x0,	    len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x20000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x40000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x0,     len=0x20000, ddir=1, file=/dev/mmcblk0p3
Io 5646 complete: io_u 0x560337a20840: off=0x60000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x80000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x20000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x40000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0x60000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 5646 complete: io_u 0x560337a20840: off=0xa0000, len=0x20000, ddir=0, file=/dev/mmcblk0p3

After the fix max-address = 0x120000 = size – len:

io 32594 complete: io_u 0x70fc000980: off=0x0,     len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x20000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x40000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x0,     len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x60000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x80000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x20000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x40000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x60000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0xa0000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x80000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0xc0000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0xa0000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0xe0000, len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x100000,len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x120000,len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0xc0000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0xe0000, len=0x20000, ddir=1, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x0,     len=0x20000, ddir=0, file=/dev/mmcblk0p3
io 32594 complete: io_u 0x70fc000980: off=0x20000, len=0x20000, ddir=0, file=/dev/mmcblk0p3

Fixes: ac002339c382 (Fix bug with rw sequence offset and io_limit)
Signed-off-by: Chana-Zaks-wdc <chana.zaks@wdc.com>
Link: https://lore.kernel.org/r/20240418092222.20543-2-chana.zaks@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>