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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-10-10 13:26:27 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-10-10 13:36:06 -0400 |
| commit | c3a690240423fc4eb8a0c3c7df025d13eadf140b (patch) | |
| tree | 20f4a32910427c2aa4ccf8e33633d6e7194628bf | |
| parent | a949e63992469fed87aef197347960ced31701b8 (diff) | |
| download | linux-c3a690240423fc4eb8a0c3c7df025d13eadf140b.tar.gz linux-c3a690240423fc4eb8a0c3c7df025d13eadf140b.tar.bz2 linux-c3a690240423fc4eb8a0c3c7df025d13eadf140b.zip | |
fix ITER_PIPE interaction with direct_IO
by making sure we call iov_iter_advance() on original
iov_iter even if direct_IO (done on its copy) has returned 0.
It's a no-op for old iov_iter flavours and does the right thing
(== truncation of the stuff we'd allocated, but not filled) in
ITER_PIPE case. Failures (e.g. -EIO) get caught and dealt with
by cleanup in generic_file_read_iter().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/splice.c | 12 | ||||
| -rw-r--r-- | fs/xfs/xfs_file.c | 2 | ||||
| -rw-r--r-- | mm/filemap.c | 2 |
3 files changed, 5 insertions, 11 deletions
diff --git a/fs/splice.c b/fs/splice.c index aa38901a4f10..153d4f3bd441 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -315,15 +315,9 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, *ppos = kiocb.ki_pos; file_accessed(in); } else if (ret < 0) { - if (WARN_ON(to.idx != idx || to.iov_offset)) { - /* - * a bogus ->read_iter() has copied something and still - * returned an error instead of a short read. - */ - to.idx = idx; - to.iov_offset = 0; - iov_iter_advance(&to, 0); /* to free what was emitted */ - } + to.idx = idx; + to.iov_offset = 0; + iov_iter_advance(&to, 0); /* to free what was emitted */ /* * callers of ->splice_read() expect -EAGAIN on * "can't put anything in there", rather than -EFAULT. diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 92f16cfb81e8..26cf153e3714 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -317,7 +317,7 @@ xfs_file_dio_aio_read( data = *to; ret = __blockdev_direct_IO(iocb, inode, target->bt_bdev, &data, xfs_get_blocks_direct, NULL, NULL, 0); - if (ret > 0) { + if (ret >= 0) { iocb->ki_pos += ret; iov_iter_advance(to, ret); } diff --git a/mm/filemap.c b/mm/filemap.c index 8a287dfc5372..6b965efe215e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1920,7 +1920,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) retval = mapping->a_ops->direct_IO(iocb, &data); } - if (retval > 0) { + if (retval >= 0) { iocb->ki_pos += retval; iov_iter_advance(iter, retval); } |