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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 22:13:46 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 22:13:46 +0300
commit7b7699c09f66f180b9a8a5010df352acb8683bfa (patch)
tree5f5e4472beba0cf247dc9003aced072e65172791
parent70868a180501d17fea58153c649d56bc18435315 (diff)
parent89c2b3b74918200e46699338d7bcc19b1ea12110 (diff)
downloadlinux-7b7699c09f66f180b9a8a5010df352acb8683bfa.tar.xz
Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter fixes from Al Viro: "Fixes for io-uring handling of iov_iter reexpands" * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: io_uring: reexpand under-reexpanded iters iov_iter: track truncated size
-rw-r--r--fs/io_uring.c2
-rw-r--r--include/linux/uio.h6
2 files changed, 7 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index d816c09c88a5..855ea544807f 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3480,6 +3480,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
if (req->flags & REQ_F_NOWAIT)
goto done;
/* some cases will consume bytes even on error returns */
+ iov_iter_reexpand(iter, iter->count + iter->truncated);
iov_iter_revert(iter, io_size - iov_iter_count(iter));
ret = 0;
} else if (ret == -EIOCBQUEUED) {
@@ -3619,6 +3620,7 @@ done:
} else {
copy_iov:
/* some cases will consume bytes even on error returns */
+ iov_iter_reexpand(iter, iter->count + iter->truncated);
iov_iter_revert(iter, io_size - iov_iter_count(iter));
ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
return ret ?: -EAGAIN;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 82c3c3e819e0..5265024e8b90 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -47,6 +47,7 @@ struct iov_iter {
};
loff_t xarray_start;
};
+ size_t truncated;
};
static inline enum iter_type iov_iter_type(const struct iov_iter *i)
@@ -254,8 +255,10 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
* conversion in assignement is by definition greater than all
* values of size_t, including old i->count.
*/
- if (i->count > count)
+ if (i->count > count) {
+ i->truncated += i->count - count;
i->count = count;
+ }
}
/*
@@ -264,6 +267,7 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
*/
static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
{
+ i->truncated -= count - i->count;
i->count = count;
}