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Message-Id: <1477845724-27586-4-git-send-email-hch@lst.de>
Date: Sun, 30 Oct 2016 11:42:03 -0500
From: Christoph Hellwig <hch@....de>
To: Linus Torvalds <torvalds@...ux-foundation.org>,
Al Viro <viro@...iv.linux.org.uk>
Cc: Jan Kara <jack@...e.cz>, Dmitry Monakhov <dmonakhov@...nvz.org>,
Jeff Moyer <jmoyer@...hat.com>, linux-fsdevel@...r.kernel.org,
linux-aio@...ck.org, linux-kernel@...r.kernel.org
Subject: [PATCH 3/4] fs: remove aio_run_iocb
Pass the ABI iocb structure to aio_setup_rw and let it handle the
non-vectored I/O case as well. With that and a new helper for the AIO
return value handling we can now define new aio_read and aio_write
helpers that implement reads and writes in a self-contained way without
duplicating too much code.
Signed-off-by: Christoph Hellwig <hch@....de>
---
fs/aio.c | 182 +++++++++++++++++++++++++++++++++------------------------------
1 file changed, 94 insertions(+), 88 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index 2a6030a..c197551 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1392,110 +1392,100 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
return -EINVAL;
}
-typedef ssize_t (rw_iter_op)(struct kiocb *, struct iov_iter *);
-
-static int aio_setup_vectored_rw(int rw, char __user *buf, size_t len,
- struct iovec **iovec,
- bool compat,
- struct iov_iter *iter)
+static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec,
+ bool vectored, bool compat, struct iov_iter *iter)
{
+ void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
+ size_t len = iocb->aio_nbytes;
+
+ if (!vectored) {
+ ssize_t ret = import_single_range(rw, buf, len, *iovec, iter);
+ *iovec = NULL;
+ return ret;
+ }
#ifdef CONFIG_COMPAT
if (compat)
- return compat_import_iovec(rw,
- (struct compat_iovec __user *)buf,
- len, UIO_FASTIOV, iovec, iter);
+ return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec,
+ iter);
#endif
- return import_iovec(rw, (struct iovec __user *)buf,
- len, UIO_FASTIOV, iovec, iter);
+ return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter);
}
-/*
- * aio_run_iocb:
- * Performs the initial checks and io submission.
- */
-static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
- char __user *buf, size_t len, bool compat)
+static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret)
+{
+ switch (ret) {
+ case -EIOCBQUEUED:
+ return ret;
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ case -ERESTARTNOHAND:
+ case -ERESTART_RESTARTBLOCK:
+ /*
+ * There's no easy way to restart the syscall since other AIO's
+ * may be already running. Just fail this IO with EINTR.
+ */
+ ret = -EINTR;
+ /*FALLTHRU*/
+ default:
+ aio_complete(req, ret, 0);
+ return 0;
+ }
+}
+
+static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored,
+ bool compat)
{
struct file *file = req->ki_filp;
- ssize_t ret;
- int rw;
- fmode_t mode;
- rw_iter_op *iter_op;
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct iov_iter iter;
+ ssize_t ret;
- switch (opcode) {
- case IOCB_CMD_PREAD:
- case IOCB_CMD_PREADV:
- mode = FMODE_READ;
- rw = READ;
- iter_op = file->f_op->read_iter;
- goto rw_common;
-
- case IOCB_CMD_PWRITE:
- case IOCB_CMD_PWRITEV:
- mode = FMODE_WRITE;
- rw = WRITE;
- iter_op = file->f_op->write_iter;
- goto rw_common;
-rw_common:
- if (unlikely(!(file->f_mode & mode)))
- return -EBADF;
-
- if (!iter_op)
- return -EINVAL;
-
- if (opcode == IOCB_CMD_PREADV || opcode == IOCB_CMD_PWRITEV)
- ret = aio_setup_vectored_rw(rw, buf, len,
- &iovec, compat, &iter);
- else {
- ret = import_single_range(rw, buf, len, iovec, &iter);
- iovec = NULL;
- }
- if (!ret)
- ret = rw_verify_area(rw, file, &req->ki_pos,
- iov_iter_count(&iter));
- if (ret < 0) {
- kfree(iovec);
- return ret;
- }
-
- get_file(file);
- if (rw == WRITE)
- file_start_write(file);
+ if (unlikely(!(file->f_mode & FMODE_READ)))
+ return -EBADF;
+ if (unlikely(!file->f_op->read_iter))
+ return -EINVAL;
- ret = iter_op(req, &iter);
+ ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter);
+ if (ret)
+ return ret;
+ ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
+ if (!ret)
+ ret = aio_ret(req, file->f_op->read_iter(req, &iter));
+ kfree(iovec);
+ return ret;
+}
- if (rw == WRITE)
- file_end_write(file);
- fput(file);
- kfree(iovec);
- break;
+static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
+ bool compat)
+{
+ struct file *file = req->ki_filp;
+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
+ struct iov_iter iter;
+ ssize_t ret;
- default:
- pr_debug("EINVAL: no operation provided\n");
+ if (unlikely(!(file->f_mode & FMODE_WRITE)))
+ return -EBADF;
+ if (unlikely(!file->f_op->write_iter))
return -EINVAL;
- }
- if (ret != -EIOCBQUEUED) {
- /*
- * There's no easy way to restart the syscall since other AIO's
- * may be already running. Just fail this IO with EINTR.
- */
- if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR ||
- ret == -ERESTARTNOHAND ||
- ret == -ERESTART_RESTARTBLOCK))
- ret = -EINTR;
- aio_complete(req, ret, 0);
+ ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter);
+ if (ret)
+ return ret;
+ ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
+ if (!ret) {
+ file_start_write(file);
+ ret = aio_ret(req, file->f_op->write_iter(req, &iter));
+ file_end_write(file);
}
-
- return 0;
+ kfree(iovec);
+ return ret;
}
static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
struct iocb *iocb, bool compat)
{
struct aio_kiocb *req;
+ struct file *file;
ssize_t ret;
/* enforce forwards compatibility on users */
@@ -1518,7 +1508,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
if (unlikely(!req))
return -EAGAIN;
- req->common.ki_filp = fget(iocb->aio_fildes);
+ req->common.ki_filp = file = fget(iocb->aio_fildes);
if (unlikely(!req->common.ki_filp)) {
ret = -EBADF;
goto out_put_req;
@@ -1553,13 +1543,29 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
req->ki_user_iocb = user_iocb;
req->ki_user_data = iocb->aio_data;
- ret = aio_run_iocb(&req->common, iocb->aio_lio_opcode,
- (char __user *)(unsigned long)iocb->aio_buf,
- iocb->aio_nbytes,
- compat);
- if (ret)
- goto out_put_req;
+ get_file(file);
+ switch (iocb->aio_lio_opcode) {
+ case IOCB_CMD_PREAD:
+ ret = aio_read(&req->common, iocb, false, compat);
+ break;
+ case IOCB_CMD_PWRITE:
+ ret = aio_write(&req->common, iocb, false, compat);
+ break;
+ case IOCB_CMD_PREADV:
+ ret = aio_read(&req->common, iocb, true, compat);
+ break;
+ case IOCB_CMD_PWRITEV:
+ ret = aio_write(&req->common, iocb, true, compat);
+ break;
+ default:
+ pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
+ ret = -EINVAL;
+ break;
+ }
+ fput(file);
+ if (ret && ret != -EIOCBQUEUED)
+ goto out_put_req;
return 0;
out_put_req:
put_reqs_available(ctx, 1);
--
2.1.4
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