* [PATCH v3] block: remove plugging at buffered write time
@ 2012-05-06 6:03 Fengguang Wu
2012-05-06 6:04 ` [PATCH] block: move down direct IO plugging Fengguang Wu
0 siblings, 1 reply; 2+ messages in thread
From: Fengguang Wu @ 2012-05-06 6:03 UTC (permalink / raw)
To: Andrew Morton
Cc: Jens Axboe, linux-fsdevel, LKML, Dave Chinner, Christoph Hellwig,
Jan Kara, Chris Mason, Shaohua Li, Jeff Moyer
Buffered write(2) is not directly tied to IO, so it's not suitable to
handle plug in generic_file_aio_write().
Note that plugging for O_SYNC writes is also removed. The user may pass
arbitrary @size arguments, which may be much larger than the preferable
I/O size, or may cross extent/device boundaries. Let the lower layers
handle the plugging. The plugging code here actually turns them into
no-ops.
CC: Jens Axboe <axboe@kernel.dk>
CC: Li Shaohua <shli@fusionio.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
fs/direct-io.c | 5 +++++
mm/filemap.c | 7 -------
2 files changed, 5 insertions(+), 7 deletions(-)
--- linux-next.orig/mm/filemap.c 2012-04-25 12:16:57.496149458 +0800
+++ linux-next/mm/filemap.c 2012-04-25 12:17:00.116149521 +0800
@@ -2605,13 +2601,11 @@ ssize_t generic_file_aio_write(struct ki
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
- struct blk_plug plug;
ssize_t ret;
BUG_ON(iocb->ki_pos != pos);
mutex_lock(&inode->i_mutex);
- blk_start_plug(&plug);
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
@@ -2622,7 +2616,6 @@ ssize_t generic_file_aio_write(struct ki
if (err < 0 && ret > 0)
ret = err;
}
- blk_finish_plug(&plug);
return ret;
}
EXPORT_SYMBOL(generic_file_aio_write);
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH] block: move down direct IO plugging
2012-05-06 6:03 [PATCH v3] block: remove plugging at buffered write time Fengguang Wu
@ 2012-05-06 6:04 ` Fengguang Wu
0 siblings, 0 replies; 2+ messages in thread
From: Fengguang Wu @ 2012-05-06 6:04 UTC (permalink / raw)
To: Andrew Morton
Cc: Jens Axboe, linux-fsdevel, LKML, Dave Chinner, Christoph Hellwig,
Jan Kara, Chris Mason, Shaohua Li, Jeff Moyer
Move unplugging for direct I/O from around ->direct_IO() down to
do_blockdev_direct_IO(). This implicitly adds plugging for direct
writes.
CC: Jens Axboe <axboe@kernel.dk>
CC: Li Shaohua <shli@fusionio.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
fs/direct-io.c | 5 +++++
mm/filemap.c | 4 ----
2 files changed, 5 insertions(+), 4 deletions(-)
--- linux-next.orig/mm/filemap.c 2012-05-03 19:32:58.051123379 +0800
+++ linux-next/mm/filemap.c 2012-05-03 19:33:27.235124073 +0800
@@ -1413,12 +1413,8 @@ generic_file_aio_read(struct kiocb *iocb
retval = filemap_write_and_wait_range(mapping, pos,
pos + iov_length(iov, nr_segs) - 1);
if (!retval) {
- struct blk_plug plug;
-
- blk_start_plug(&plug);
retval = mapping->a_ops->direct_IO(READ, iocb,
iov, pos, nr_segs);
- blk_finish_plug(&plug);
}
if (retval > 0) {
*ppos = pos + retval;
--- linux-next.orig/fs/direct-io.c 2012-05-03 19:32:57.000000000 +0800
+++ linux-next/fs/direct-io.c 2012-05-03 19:33:27.235124073 +0800
@@ -1106,6 +1106,7 @@ do_blockdev_direct_IO(int rw, struct kio
unsigned long user_addr;
size_t bytes;
struct buffer_head map_bh = { 0, };
+ struct blk_plug plug;
if (rw & WRITE)
rw = WRITE_ODIRECT;
@@ -1221,6 +1222,8 @@ do_blockdev_direct_IO(int rw, struct kio
PAGE_SIZE - user_addr / PAGE_SIZE);
}
+ blk_start_plug(&plug);
+
for (seg = 0; seg < nr_segs; seg++) {
user_addr = (unsigned long)iov[seg].iov_base;
sdio.size += bytes = iov[seg].iov_len;
@@ -1279,6 +1282,8 @@ do_blockdev_direct_IO(int rw, struct kio
if (sdio.bio)
dio_bio_submit(dio, &sdio);
+ blk_finish_plug(&plug);
+
/*
* It is possible that, we return short IO due to end of file.
* In that case, we need to release all the pages we got hold on.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2012-05-06 9:11 UTC | newest]
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