Back in the days when the direct I/O ->end_io callback could be called
from interrupt context for AIO we needed a structure to hand off to the
workqueue, and reused the ioend structure for this purpose. These days
->end_io is always called from user or workqueue context, which allows us
to avoid this memory allocation and simplify the code significantly.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/xfs_aops.c | 133 ++++++++++++++++++++++++------------------------------
fs/xfs/xfs_aops.h | 3 --
2 files changed, 59 insertions(+), 77 deletions(-)
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 18e2f3b..31d3d7d 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -135,30 +135,22 @@ xfs_setfilesize_trans_alloc(
*/
STATIC int
xfs_setfilesize(
- struct xfs_ioend *ioend)
+ struct xfs_inode *ip,
+ struct xfs_trans *tp,
+ xfs_off_t offset,
+ size_t size)
{
- struct xfs_inode *ip = XFS_I(ioend->io_inode);
- struct xfs_trans *tp = ioend->io_append_trans;
xfs_fsize_t isize;
- /*
- * The transaction may have been allocated in the I/O submission thread,
- * thus we need to mark ourselves as beeing in a transaction manually.
- * Similarly for freeze protection.
- */
- current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
- rwsem_acquire_read(&VFS_I(ip)->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
- 0, 1, _THIS_IP_);
-
xfs_ilock(ip, XFS_ILOCK_EXCL);
- isize = xfs_new_eof(ip, ioend->io_offset + ioend->io_size);
+ isize = xfs_new_eof(ip, offset + size);
if (!isize) {
xfs_iunlock(ip, XFS_ILOCK_EXCL);
xfs_trans_cancel(tp, 0);
return 0;
}
- trace_xfs_setfilesize(ip, ioend->io_offset, ioend->io_size);
+ trace_xfs_setfilesize(ip, offset, size);
ip->i_d.di_size = isize;
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
@@ -167,6 +159,25 @@ xfs_setfilesize(
return xfs_trans_commit(tp, 0);
}
+STATIC int
+xfs_setfilesize_ioend(
+ struct xfs_ioend *ioend)
+{
+ struct xfs_inode *ip = XFS_I(ioend->io_inode);
+ struct xfs_trans *tp = ioend->io_append_trans;
+
+ /*
+ * The transaction may have been allocated in the I/O submission thread,
+ * thus we need to mark ourselves as beeing in a transaction manually.
+ * Similarly for freeze protection.
+ */
+ current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
+ rwsem_acquire_read(&VFS_I(ip)->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
+ 0, 1, _THIS_IP_);
+
+ return xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
+}
+
/*
* Schedule IO completion handling on the final put of an ioend.
*
@@ -182,8 +193,7 @@ xfs_finish_ioend(
if (ioend->io_type == XFS_IO_UNWRITTEN)
queue_work(mp->m_unwritten_workqueue, &ioend->io_work);
- else if (ioend->io_append_trans ||
- (ioend->io_isdirect && xfs_ioend_is_append(ioend)))
+ else if (ioend->io_append_trans)
queue_work(mp->m_data_workqueue, &ioend->io_work);
else
xfs_destroy_ioend(ioend);
@@ -215,22 +225,8 @@ xfs_end_io(
if (ioend->io_type == XFS_IO_UNWRITTEN) {
error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
ioend->io_size);
- } else if (ioend->io_isdirect && xfs_ioend_is_append(ioend)) {
- /*
- * For direct I/O we do not know if we need to allocate blocks
- * or not so we can't preallocate an append transaction as that
- * results in nested reservations and log space deadlocks. Hence
- * allocate the transaction here. While this is sub-optimal and
- * can block IO completion for some time, we're stuck with doing
- * it this way until we can pass the ioend to the direct IO
- * allocation callbacks and avoid nesting that way.
- */
- error = xfs_setfilesize_trans_alloc(ioend);
- if (error)
- goto done;
- error = xfs_setfilesize(ioend);
} else if (ioend->io_append_trans) {
- error = xfs_setfilesize(ioend);
+ error = xfs_setfilesize_ioend(ioend);
} else {
ASSERT(!xfs_ioend_is_append(ioend));
}
@@ -273,7 +269,6 @@ xfs_alloc_ioend(
* all the I/O from calling the completion routine too early.
*/
atomic_set(&ioend->io_remaining, 1);
- ioend->io_isdirect = 0;
ioend->io_error = 0;
ioend->io_list = NULL;
ioend->io_type = type;
@@ -1459,11 +1454,7 @@ xfs_get_blocks_direct(
*
* If the private argument is non-NULL __xfs_get_blocks signals us that we
* need to issue a transaction to convert the range from unwritten to written
- * extents. In case this is regular synchronous I/O we just call xfs_end_io
- * to do this and we are done. But in case this was a successful AIO
- * request this handler is called from interrupt context, from which we
- * can't start transactions. In that case offload the I/O completion to
- * the workqueues we also use for buffered I/O completion.
+ * extents.
*/
STATIC void
xfs_end_io_direct_write(
@@ -1472,7 +1463,12 @@ xfs_end_io_direct_write(
ssize_t size,
void *private)
{
- struct xfs_ioend *ioend = iocb->private;
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return;
/*
* While the generic direct I/O code updates the inode size, it does
@@ -1480,22 +1476,33 @@ xfs_end_io_direct_write(
* end_io handler thinks the on-disk size is outside the in-core
* size. To prevent this just update it a little bit earlier here.
*/
- if (offset + size > i_size_read(ioend->io_inode))
- i_size_write(ioend->io_inode, offset + size);
+ if (offset + size > i_size_read(inode))
+ i_size_write(inode, offset + size);
/*
- * blockdev_direct_IO can return an error even after the I/O
- * completion handler was called. Thus we need to protect
- * against double-freeing.
+ * For direct I/O we do not know if we need to allocate blocks or not,
+ * so we can't preallocate an append transaction, as that results in
+ * nested reservations and log space deadlocks. Hence allocate the
+ * transaction here. While this is sub-optimal and can block IO
+ * completion for some time, we're stuck with doing it this way until
+ * we can pass the ioend to the direct IO allocation callbacks and
+ * avoid nesting that way.
*/
- iocb->private = NULL;
-
- ioend->io_offset = offset;
- ioend->io_size = size;
- if (private && size > 0)
- ioend->io_type = XFS_IO_UNWRITTEN;
+ if (private && size > 0) {
+ xfs_iomap_write_unwritten(ip, offset, size);
+ } else if (offset + size > ip->i_d.di_size) {
+ struct xfs_trans *tp;
+ int error;
+
+ tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
+ error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0);
+ if (error) {
+ xfs_trans_cancel(tp, 0);
+ return;
+ }
- xfs_finish_ioend_sync(ioend);
+ xfs_setfilesize(ip, tp, offset, size);
+ }
}
STATIC ssize_t
@@ -1507,39 +1514,17 @@ xfs_vm_direct_IO(
{
struct inode *inode = iocb->ki_filp->f_mapping->host;
struct block_device *bdev = xfs_find_bdev_for_inode(inode);
- struct xfs_ioend *ioend = NULL;
- ssize_t ret;
if (rw & WRITE) {
- size_t size = iov_iter_count(iter);
-
- /*
- * We cannot preallocate a size update transaction here as we
- * don't know whether allocation is necessary or not. Hence we
- * can only tell IO completion that one is necessary if we are
- * not doing unwritten extent conversion.
- */
- iocb->private = ioend = xfs_alloc_ioend(inode, XFS_IO_DIRECT);
- if (offset + size > XFS_I(inode)->i_d.di_size)
- ioend->io_isdirect = 1;
-
- ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iter,
+ return __blockdev_direct_IO(rw, iocb, inode, bdev, iter,
offset, xfs_get_blocks_direct,
xfs_end_io_direct_write, NULL,
DIO_ASYNC_EXTEND);
- if (ret != -EIOCBQUEUED && iocb->private)
- goto out_destroy_ioend;
} else {
- ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iter,
+ return __blockdev_direct_IO(rw, iocb, inode, bdev, iter,
offset, xfs_get_blocks_direct,
NULL, NULL, 0);
}
-
- return ret;
-
-out_destroy_ioend:
- xfs_destroy_ioend(ioend);
- return ret;
}
/*
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index f94dd45..ac644e0 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -24,14 +24,12 @@ extern mempool_t *xfs_ioend_pool;
* Types of I/O for bmap clustering and I/O completion tracking.
*/
enum {
- XFS_IO_DIRECT = 0, /* special case for direct I/O ioends */
XFS_IO_DELALLOC, /* covers delalloc region */
XFS_IO_UNWRITTEN, /* covers allocated but uninitialized data */
XFS_IO_OVERWRITE, /* covers already allocated extent */
};
#define XFS_IO_TYPES \
- { 0, "" }, \
{ XFS_IO_DELALLOC, "delalloc" }, \
{ XFS_IO_UNWRITTEN, "unwritten" }, \
{ XFS_IO_OVERWRITE, "overwrite" }
@@ -45,7 +43,6 @@ typedef struct xfs_ioend {
unsigned int io_type; /* delalloc / unwritten */
int io_error; /* I/O error code */
atomic_t io_remaining; /* hold count */
- unsigned int io_isdirect : 1;/* direct I/O */
struct inode *io_inode; /* file being written to */
struct buffer_head *io_buffer_head;/* buffer linked list head */
struct buffer_head *io_buffer_tail;/* buffer linked list tail */
--
1.9.1
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