NTFS: Optimize fs/ntfs/aops.c::ntfs_write_block() by extending the page
lock protection over the buffer submission for i/o which allows the
removal of the get_bh()/put_bh() pairs for each buffer.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 4b8666d..10fc238 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -81,6 +81,9 @@
only zeroes.
- Fixup handling of sparse, compressed, and encrypted attributes in
fs/ntfs/aops.c::ntfs_writepage().
+ - Optimize fs/ntfs/aops.c::ntfs_write_block() by extending the page
+ lock protection over the buffer submission for i/o which allows the
+ removal of the get_bh()/put_bh() pairs for each buffer.
2.1.23 - Implement extension of resident files and make writing safe as well as
many bug fixes, cleanups, and enhancements...
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 6f2954a..821dad7 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -735,7 +735,7 @@
/* For the error case, need to reset bh to the beginning. */
bh = head;
- /* Just an optimization, so ->readpage() isn't called later. */
+ /* Just an optimization, so ->readpage() is not called later. */
if (unlikely(!PageUptodate(page))) {
int uptodate = 1;
do {
@@ -751,7 +751,6 @@
/* Setup all mapped, dirty buffers for async write i/o. */
do {
- get_bh(bh);
if (buffer_mapped(bh) && buffer_dirty(bh)) {
lock_buffer(bh);
if (test_clear_buffer_dirty(bh)) {
@@ -789,14 +788,8 @@
BUG_ON(PageWriteback(page));
set_page_writeback(page); /* Keeps try_to_free_buffers() away. */
- unlock_page(page);
- /*
- * Submit the prepared buffers for i/o. Note the page is unlocked,
- * and the async write i/o completion handler can end_page_writeback()
- * at any time after the *first* submit_bh(). So the buffers can then
- * disappear...
- */
+ /* Submit the prepared buffers for i/o. */
need_end_writeback = TRUE;
do {
struct buffer_head *next = bh->b_this_page;
@@ -804,9 +797,9 @@
submit_bh(WRITE, bh);
need_end_writeback = FALSE;
}
- put_bh(bh);
bh = next;
} while (bh != head);
+ unlock_page(page);
/* If no i/o was started, need to end_page_writeback(). */
if (unlikely(need_end_writeback))