[PATCH 09/21] aio: Kill unneeded kiocb members

From: Kent Overstreet
Date: Mon May 13 2013 - 21:24:12 EST

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The old aio retry infrastucture needed to save the various arguments to
to aio operations. But with the retry infrastructure gone, we can trim
struct kiocb quite a bit.

Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx>
Cc: Zach Brown <zab@xxxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Asai Thambi S P <asamymuthupa@xxxxxxxxxx>
Cc: Selvan Mani <smani@xxxxxxxxxx>
Cc: Sam Bradshaw <sbradshaw@xxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
---
fs/aio.c | 69 +++++++++++++++++++++++++++++++----------------------
include/linux/aio.h | 11 ++-------
2 files changed, 42 insertions(+), 38 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 73ec062..280b014 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -637,8 +637,6 @@ static void kiocb_free(struct kiocb *req)
eventfd_ctx_put(req->ki_eventfd);
if (req->ki_dtor)
req->ki_dtor(req);
- if (req->ki_iovec != &req->ki_inline_vec)
- kfree(req->ki_iovec);
kmem_cache_free(kiocb_cachep, req);
}

@@ -968,24 +966,26 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
typedef ssize_t (aio_rw_op)(struct kiocb *, const struct iovec *,
unsigned long, loff_t);

-static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat)
+static ssize_t aio_setup_vectored_rw(struct kiocb *kiocb,
+ int rw, char __user *buf,
+ unsigned long *nr_segs,
+ struct iovec **iovec,
+ bool compat)
{
ssize_t ret;

- kiocb->ki_nr_segs = kiocb->ki_nbytes;
+ *nr_segs = kiocb->ki_nbytes;

#ifdef CONFIG_COMPAT
if (compat)
ret = compat_rw_copy_check_uvector(rw,
- (struct compat_iovec __user *)kiocb->ki_buf,
- kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
- &kiocb->ki_iovec);
+ (struct compat_iovec __user *)buf,
+ *nr_segs, 1, *iovec, iovec);
else
#endif
ret = rw_copy_check_uvector(rw,
- (struct iovec __user *)kiocb->ki_buf,
- kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
- &kiocb->ki_iovec);
+ (struct iovec __user *)buf,
+ *nr_segs, 1, *iovec, iovec);
if (ret < 0)
return ret;

@@ -994,15 +994,17 @@ static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat)
return 0;
}

-static ssize_t aio_setup_single_vector(int rw, struct kiocb *kiocb)
+static ssize_t aio_setup_single_vector(struct kiocb *kiocb,
+ int rw, char __user *buf,
+ unsigned long *nr_segs,
+ struct iovec *iovec)
{
- if (unlikely(!access_ok(!rw, kiocb->ki_buf, kiocb->ki_nbytes)))
+ if (unlikely(!access_ok(!rw, buf, kiocb->ki_nbytes)))
return -EFAULT;

- kiocb->ki_iovec = &kiocb->ki_inline_vec;
- kiocb->ki_iovec->iov_base = kiocb->ki_buf;
- kiocb->ki_iovec->iov_len = kiocb->ki_nbytes;
- kiocb->ki_nr_segs = 1;
+ iovec->iov_base = buf;
+ iovec->iov_len = kiocb->ki_nbytes;
+ *nr_segs = 1;
return 0;
}

@@ -1011,15 +1013,18 @@ static ssize_t aio_setup_single_vector(int rw, struct kiocb *kiocb)
* Performs the initial checks and aio retry method
* setup for the kiocb at the time of io submission.
*/
-static ssize_t aio_run_iocb(struct kiocb *req, bool compat)
+static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
+ char __user *buf, bool compat)
{
struct file *file = req->ki_filp;
ssize_t ret;
+ unsigned long nr_segs;
int rw;
fmode_t mode;
aio_rw_op *rw_op;
+ struct iovec inline_vec, *iovec = &inline_vec;

- switch (req->ki_opcode) {
+ switch (opcode) {
case IOCB_CMD_PREAD:
case IOCB_CMD_PREADV:
mode = FMODE_READ;
@@ -1040,16 +1045,21 @@ rw_common:
if (!rw_op)
return -EINVAL;

- ret = (req->ki_opcode == IOCB_CMD_PREADV ||
- req->ki_opcode == IOCB_CMD_PWRITEV)
- ? aio_setup_vectored_rw(rw, req, compat)
- : aio_setup_single_vector(rw, req);
+ ret = (opcode == IOCB_CMD_PREADV ||
+ opcode == IOCB_CMD_PWRITEV)
+ ? aio_setup_vectored_rw(req, rw, buf, &nr_segs,
+ &iovec, compat)
+ : aio_setup_single_vector(req, rw, buf, &nr_segs,
+ iovec);
if (ret)
return ret;

ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes);
- if (ret < 0)
+ if (ret < 0) {
+ if (iovec != &inline_vec)
+ kfree(iovec);
return ret;
+ }

req->ki_nbytes = ret;

@@ -1063,8 +1073,7 @@ rw_common:
if (rw == WRITE)
file_start_write(file);

- ret = rw_op(req, req->ki_iovec,
- req->ki_nr_segs, req->ki_pos);
+ ret = rw_op(req, iovec, nr_segs, req->ki_pos);

if (rw == WRITE)
file_end_write(file);
@@ -1089,6 +1098,9 @@ rw_common:
return -EINVAL;
}

+ if (iovec != &inline_vec)
+ kfree(iovec);
+
if (ret != -EIOCBQUEUED) {
/*
* There's no easy way to restart the syscall since other AIO's
@@ -1160,12 +1172,11 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
req->ki_obj.user = user_iocb;
req->ki_user_data = iocb->aio_data;
req->ki_pos = iocb->aio_offset;
-
- req->ki_buf = (char __user *)(unsigned long)iocb->aio_buf;
req->ki_nbytes = iocb->aio_nbytes;
- req->ki_opcode = iocb->aio_lio_opcode;

- ret = aio_run_iocb(req, compat);
+ ret = aio_run_iocb(req, iocb->aio_lio_opcode,
+ (char __user *)(unsigned long)iocb->aio_buf,
+ compat);
if (ret)
goto out_put_req;

diff --git a/include/linux/aio.h b/include/linux/aio.h
index 7bb766e..b570472 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -36,6 +36,7 @@ struct kiocb {
struct kioctx *ki_ctx; /* NULL for sync ops */
kiocb_cancel_fn *ki_cancel;
void (*ki_dtor)(struct kiocb *);
+ void *private;

union {
void __user *user;
@@ -44,15 +45,7 @@ struct kiocb {

__u64 ki_user_data; /* user's data for completion */
loff_t ki_pos;
-
- void *private;
- /* State that we remember to be able to restart/retry */
- unsigned short ki_opcode;
- size_t ki_nbytes; /* copy of iocb->aio_nbytes */
- char __user *ki_buf; /* remaining iocb->aio_buf */
- struct iovec ki_inline_vec; /* inline vector */
- struct iovec *ki_iovec;
- unsigned long ki_nr_segs;
+ size_t ki_nbytes; /* copy of iocb->aio_nbytes */

struct list_head ki_list; /* the aio core uses this
* for cancellation */
--
1.8.2.1

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Next message: Kent Overstreet: "[PATCH 02/21] aio: reqs_active -> reqs_available"
Previous message: Kent Overstreet: "[PATCH 07/21] aio: Don't use ctx->tail unnecessarily"
In reply to: Kent Overstreet: "[PATCH 07/21] aio: Don't use ctx->tail unnecessarily"
Next in thread: Kent Overstreet: "[PATCH 02/21] aio: reqs_active -> reqs_available"
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