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authorKent Overstreet <koverstreet@google.com>2013-05-07 16:19:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-07 19:46:02 -0700
commit41ef4eb8eef8d06bc1399e7b00c940d771554711 (patch)
tree3b8194de916d638f73394ed4b9c8910bbab04feb
parent8a6608907cf165b3ae658c9de2efe6af4be68bff (diff)
downloadlinaro-lsk-41ef4eb8eef8d06bc1399e7b00c940d771554711.tar.gz
aio: kill ki_retry
Thanks to Zach Brown's work to rip out the retry infrastructure, we don't need this anymore - ki_retry was only called right after the kiocb was initialized. This also refactors and trims some duplicated code, as well as cleaning up the refcounting/error handling a bit. [akpm@linux-foundation.org: use fmode_t in aio_run_iocb()] [akpm@linux-foundation.org: fix file_start_write/file_end_write tests] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/aio.c224
-rw-r--r--include/linux/aio.h26
2 files changed, 85 insertions, 165 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 5d7dad365f5..c5b1a8c1041 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -903,30 +903,21 @@ static void aio_advance_iovec(struct kiocb *iocb, ssize_t ret)
BUG_ON(ret > 0 && iocb->ki_left == 0);
}
-static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
+typedef ssize_t (aio_rw_op)(struct kiocb *, const struct iovec *,
+ unsigned long, loff_t);
+
+static ssize_t aio_rw_vect_retry(struct kiocb *iocb, int rw, aio_rw_op *rw_op)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
- ssize_t (*rw_op)(struct kiocb *, const struct iovec *,
- unsigned long, loff_t);
ssize_t ret = 0;
- unsigned short opcode;
-
- if ((iocb->ki_opcode == IOCB_CMD_PREADV) ||
- (iocb->ki_opcode == IOCB_CMD_PREAD)) {
- rw_op = file->f_op->aio_read;
- opcode = IOCB_CMD_PREADV;
- } else {
- rw_op = file->f_op->aio_write;
- opcode = IOCB_CMD_PWRITEV;
- }
/* This matches the pread()/pwrite() logic */
if (iocb->ki_pos < 0)
return -EINVAL;
- if (opcode == IOCB_CMD_PWRITEV)
+ if (rw == WRITE)
file_start_write(file);
do {
ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg],
@@ -938,9 +929,9 @@ static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
/* retry all partial writes. retry partial reads as long as its a
* regular file. */
} while (ret > 0 && iocb->ki_left > 0 &&
- (opcode == IOCB_CMD_PWRITEV ||
+ (rw == WRITE ||
(!S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode))));
- if (opcode == IOCB_CMD_PWRITEV)
+ if (rw == WRITE)
file_end_write(file);
/* This means we must have transferred all that we could */
@@ -950,7 +941,7 @@ static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
/* If we managed to write some out we return that, rather than
* the eventual error. */
- if (opcode == IOCB_CMD_PWRITEV
+ if (rw == WRITE
&& ret < 0 && ret != -EIOCBQUEUED
&& iocb->ki_nbytes - iocb->ki_left)
ret = iocb->ki_nbytes - iocb->ki_left;
@@ -958,73 +949,41 @@ static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
return ret;
}
-static ssize_t aio_fdsync(struct kiocb *iocb)
-{
- struct file *file = iocb->ki_filp;
- ssize_t ret = -EINVAL;
-
- if (file->f_op->aio_fsync)
- ret = file->f_op->aio_fsync(iocb, 1);
- return ret;
-}
-
-static ssize_t aio_fsync(struct kiocb *iocb)
-{
- struct file *file = iocb->ki_filp;
- ssize_t ret = -EINVAL;
-
- if (file->f_op->aio_fsync)
- ret = file->f_op->aio_fsync(iocb, 0);
- return ret;
-}
-
-static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
+static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat)
{
ssize_t ret;
+ kiocb->ki_nr_segs = kiocb->ki_nbytes;
+
#ifdef CONFIG_COMPAT
if (compat)
- ret = compat_rw_copy_check_uvector(type,
+ ret = compat_rw_copy_check_uvector(rw,
(struct compat_iovec __user *)kiocb->ki_buf,
- kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
+ kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
&kiocb->ki_iovec);
else
#endif
- ret = rw_copy_check_uvector(type,
+ ret = rw_copy_check_uvector(rw,
(struct iovec __user *)kiocb->ki_buf,
- kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
+ kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
&kiocb->ki_iovec);
if (ret < 0)
- goto out;
-
- ret = rw_verify_area(type, kiocb->ki_filp, &kiocb->ki_pos, ret);
- if (ret < 0)
- goto out;
+ return ret;
- kiocb->ki_nr_segs = kiocb->ki_nbytes;
- kiocb->ki_cur_seg = 0;
- /* ki_nbytes/left now reflect bytes instead of segs */
+ /* ki_nbytes now reflect bytes instead of segs */
kiocb->ki_nbytes = ret;
- kiocb->ki_left = ret;
-
- ret = 0;
-out:
- return ret;
+ return 0;
}
-static ssize_t aio_setup_single_vector(int type, struct file * file, struct kiocb *kiocb)
+static ssize_t aio_setup_single_vector(int rw, struct kiocb *kiocb)
{
- int bytes;
-
- bytes = rw_verify_area(type, file, &kiocb->ki_pos, kiocb->ki_left);
- if (bytes < 0)
- return bytes;
+ if (unlikely(!access_ok(!rw, kiocb->ki_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 = bytes;
+ kiocb->ki_iovec->iov_len = kiocb->ki_nbytes;
kiocb->ki_nr_segs = 1;
- kiocb->ki_cur_seg = 0;
return 0;
}
@@ -1033,81 +992,82 @@ static ssize_t aio_setup_single_vector(int type, struct file * file, struct kioc
* Performs the initial checks and aio retry method
* setup for the kiocb at the time of io submission.
*/
-static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
+static ssize_t aio_run_iocb(struct kiocb *req, bool compat)
{
- struct file *file = kiocb->ki_filp;
- ssize_t ret = 0;
+ struct file *file = req->ki_filp;
+ ssize_t ret;
+ int rw;
+ fmode_t mode;
+ aio_rw_op *rw_op;
- switch (kiocb->ki_opcode) {
+ switch (req->ki_opcode) {
case IOCB_CMD_PREAD:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_READ)))
- break;
- ret = -EFAULT;
- if (unlikely(!access_ok(VERIFY_WRITE, kiocb->ki_buf,
- kiocb->ki_left)))
- break;
- ret = aio_setup_single_vector(READ, file, kiocb);
- if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_read)
- kiocb->ki_retry = aio_rw_vect_retry;
- break;
- case IOCB_CMD_PWRITE:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_WRITE)))
- break;
- ret = -EFAULT;
- if (unlikely(!access_ok(VERIFY_READ, kiocb->ki_buf,
- kiocb->ki_left)))
- break;
- ret = aio_setup_single_vector(WRITE, file, kiocb);
- if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_write)
- kiocb->ki_retry = aio_rw_vect_retry;
- break;
case IOCB_CMD_PREADV:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_READ)))
- break;
- ret = aio_setup_vectored_rw(READ, kiocb, compat);
- if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_read)
- kiocb->ki_retry = aio_rw_vect_retry;
- break;
+ mode = FMODE_READ;
+ rw = READ;
+ rw_op = file->f_op->aio_read;
+ goto rw_common;
+
+ case IOCB_CMD_PWRITE:
case IOCB_CMD_PWRITEV:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_WRITE)))
- break;
- ret = aio_setup_vectored_rw(WRITE, kiocb, compat);
+ mode = FMODE_WRITE;
+ rw = WRITE;
+ rw_op = file->f_op->aio_write;
+ goto rw_common;
+rw_common:
+ if (unlikely(!(file->f_mode & mode)))
+ return -EBADF;
+
+ 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);
if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_write)
- kiocb->ki_retry = aio_rw_vect_retry;
+ return ret;
+
+ ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes);
+ if (ret < 0)
+ return ret;
+
+ req->ki_nbytes = ret;
+ req->ki_left = ret;
+
+ ret = aio_rw_vect_retry(req, rw, rw_op);
break;
+
case IOCB_CMD_FDSYNC:
- ret = -EINVAL;
- if (file->f_op->aio_fsync)
- kiocb->ki_retry = aio_fdsync;
+ if (!file->f_op->aio_fsync)
+ return -EINVAL;
+
+ ret = file->f_op->aio_fsync(req, 1);
break;
+
case IOCB_CMD_FSYNC:
- ret = -EINVAL;
- if (file->f_op->aio_fsync)
- kiocb->ki_retry = aio_fsync;
+ if (!file->f_op->aio_fsync)
+ return -EINVAL;
+
+ ret = file->f_op->aio_fsync(req, 0);
break;
+
default:
pr_debug("EINVAL: no operation provided\n");
- ret = -EINVAL;
+ return -EINVAL;
}
- if (!kiocb->ki_retry)
- return ret;
+ 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);
+ }
return 0;
}
@@ -1134,7 +1094,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
return -EINVAL;
}
- req = aio_get_req(ctx); /* returns with 2 references to req */
+ req = aio_get_req(ctx);
if (unlikely(!req))
return -EAGAIN;
@@ -1173,26 +1133,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
req->ki_left = req->ki_nbytes = iocb->aio_nbytes;
req->ki_opcode = iocb->aio_lio_opcode;
- ret = aio_setup_iocb(req, compat);
+ ret = aio_run_iocb(req, compat);
if (ret)
goto out_put_req;
- ret = req->ki_retry(req);
- 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);
- }
-
aio_put_req(req); /* drop extra ref to req */
return 0;
-
out_put_req:
atomic_dec(&ctx->reqs_active);
aio_put_req(req); /* drop extra ref to req */
diff --git a/include/linux/aio.h b/include/linux/aio.h
index 7308836dd04..1bdf965339f 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -29,38 +29,12 @@ struct kiocb;
typedef int (kiocb_cancel_fn)(struct kiocb *, struct io_event *);
-/* is there a better place to document function pointer methods? */
-/**
- * ki_retry - iocb forward progress callback
- * @kiocb: The kiocb struct to advance by performing an operation.
- *
- * This callback is called when the AIO core wants a given AIO operation
- * to make forward progress. The kiocb argument describes the operation
- * that is to be performed. As the operation proceeds, perhaps partially,
- * ki_retry is expected to update the kiocb with progress made. Typically
- * ki_retry is set in the AIO core and it itself calls file_operations
- * helpers.
- *
- * ki_retry's return value determines when the AIO operation is completed
- * and an event is generated in the AIO event ring. Except the special
- * return values described below, the value that is returned from ki_retry
- * is transferred directly into the completion ring as the operation's
- * resulting status. Once this has happened ki_retry *MUST NOT* reference
- * the kiocb pointer again.
- *
- * If ki_retry returns -EIOCBQUEUED it has made a promise that aio_complete()
- * will be called on the kiocb pointer in the future. The AIO core will
- * not ask the method again -- ki_retry must ensure forward progress.
- * aio_complete() must be called once and only once in the future, multiple
- * calls may result in undefined behaviour.
- */
struct kiocb {
atomic_t ki_users;
struct file *ki_filp;
struct kioctx *ki_ctx; /* NULL for sync ops */
kiocb_cancel_fn *ki_cancel;
- ssize_t (*ki_retry)(struct kiocb *);
void (*ki_dtor)(struct kiocb *);
union {