From 2428c08a6025301b3be28b2c3b8be7afaafe72d6 Mon Sep 17 00:00:00 2001 From: Xiao Yang Date: Mon, 27 Nov 2017 10:34:27 +0800 Subject: [PATCH] generic/465: just check the actual read data under dio read/write I got the following message when running generic/465 in ext4 data=journal mode --------------------------------------------------------------- QA output created by 465 non-aio dio test encounter an error: block 0 offset 4096, content 62 encounter an error: block 0 offset 122880, content 62 encounter an error: block 0 offset 274432, content 62 encounter an error: block 0 offset 86016, content 62 aio-dio test encounter an error: block 0 offset 28672, content 62 encounter an error: block 0 offset 12288, content 62 encounter an error: block 2 offset 16384, content 62 encounter an error: block 1 offset 565248, content 62 --------------------------------------------------------------- In ext4 data=journal mode, direct read will fall back to buffer read, and buffer read doesn't take inode lock, so it doesn't need to wait for the writer to finish first and sees the intermediate inode size and returns data less than 1M. We can just check the actual read data instead of the whole read buffer. Signed-off-by: Xiao Yang Reviewed-by: Eryu Guan Signed-off-by: Eryu Guan --- src/aio-dio-regress/aio-dio-append-write-read-race.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/src/aio-dio-regress/aio-dio-append-write-read-race.c b/src/aio-dio-regress/aio-dio-append-write-read-race.c index 8f94d503..44399477 100644 --- a/src/aio-dio-regress/aio-dio-append-write-read-race.c +++ b/src/aio-dio-regress/aio-dio-append-write-read-race.c @@ -43,6 +43,7 @@ struct io_data { off_t offset; char *buf; int use_aio; + ssize_t read_sz; }; int reader_ready = 0; @@ -57,15 +58,15 @@ static void usage(const char *prog) static void *reader(void *arg) { struct io_data *data = (struct io_data *)arg; - int ret; memset(data->buf, 'b', data->blksize); reader_ready = 1; do { - ret = pread(data->fd, data->buf, data->blksize, data->offset); - if (ret < 0) + data->read_sz = pread(data->fd, data->buf, data->blksize, + data->offset); + if (data->read_sz < 0) perror("read file"); - } while (ret <= 0); + } while (data->read_sz <= 0); return NULL; } @@ -203,7 +204,7 @@ int main(int argc, char *argv[]) goto err; } - for (j = 0; j < blksize; j++) { + for (j = 0; j < rdata.read_sz; j++) { if (rdata.buf[j] != 'a') { fail("encounter an error: " "block %d offset %d, content %x\n", -- 2.30.2