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CIFS: Separate page processing from writepages

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Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Pavel Shilovsky 2014-06-19 15:01:03 +04:00 committed by Steve French
parent 038bc961c3
commit 7e48ff8202
1 changed files with 82 additions and 70 deletions
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152
fs/cifs/file.c
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@ -1878,6 +1878,86 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
return rc;
}
static unsigned int
wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
struct address_space *mapping,
struct writeback_control *wbc,
pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
{
unsigned int nr_pages = 0, i;
struct page *page;
for (i = 0; i < found_pages; i++) {
page = wdata->pages[i];
/*
* At this point we hold neither mapping->tree_lock nor
* lock on the page itself: the page may be truncated or
* invalidated (changing page->mapping to NULL), or even
* swizzled back from swapper_space to tmpfs file
* mapping
*/
if (nr_pages == 0)
lock_page(page);
else if (!trylock_page(page))
break;
if (unlikely(page->mapping != mapping)) {
unlock_page(page);
break;
}
if (!wbc->range_cyclic && page->index > end) {
*done = true;
unlock_page(page);
break;
}
if (*next && (page->index != *next)) {
/* Not next consecutive page */
unlock_page(page);
break;
}
if (wbc->sync_mode != WB_SYNC_NONE)
wait_on_page_writeback(page);
if (PageWriteback(page) ||
!clear_page_dirty_for_io(page)) {
unlock_page(page);
break;
}
/*
* This actually clears the dirty bit in the radix tree.
* See cifs_writepage() for more commentary.
*/
set_page_writeback(page);
if (page_offset(page) >= i_size_read(mapping->host)) {
*done = true;
unlock_page(page);
end_page_writeback(page);
break;
}
wdata->pages[i] = page;
*next = page->index + 1;
++nr_pages;
}
/* reset index to refind any pages skipped */
if (nr_pages == 0)
*index = wdata->pages[0]->index + 1;
/* put any pages we aren't going to use */
for (i = nr_pages; i < found_pages; i++) {
page_cache_release(wdata->pages[i]);
wdata->pages[i] = NULL;
}
return nr_pages;
}
static int cifs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
@ -1886,7 +1966,6 @@ static int cifs_writepages(struct address_space *mapping,
pgoff_t end, index;
struct cifs_writedata *wdata;
struct TCP_Server_Info *server;
struct page *page;
int rc = 0;
/*
@ -1944,75 +2023,8 @@ retry:
break;
}
nr_pages = 0;
for (i = 0; i < found_pages; i++) {
page = wdata->pages[i];
/*
* At this point we hold neither mapping->tree_lock nor
* lock on the page itself: the page may be truncated or
* invalidated (changing page->mapping to NULL), or even
* swizzled back from swapper_space to tmpfs file
* mapping
*/
if (nr_pages == 0)
lock_page(page);
else if (!trylock_page(page))
break;
if (unlikely(page->mapping != mapping)) {
unlock_page(page);
break;
}
if (!wbc->range_cyclic && page->index > end) {
done = true;
unlock_page(page);
break;
}
if (next && (page->index != next)) {
/* Not next consecutive page */
unlock_page(page);
break;
}
if (wbc->sync_mode != WB_SYNC_NONE)
wait_on_page_writeback(page);
if (PageWriteback(page) ||
!clear_page_dirty_for_io(page)) {
unlock_page(page);
break;
}
/*
* This actually clears the dirty bit in the radix tree.
* See cifs_writepage() for more commentary.
*/
set_page_writeback(page);
if (page_offset(page) >= i_size_read(mapping->host)) {
done = true;
unlock_page(page);
end_page_writeback(page);
break;
}
wdata->pages[i] = page;
next = page->index + 1;
++nr_pages;
}
/* reset index to refind any pages skipped */
if (nr_pages == 0)
index = wdata->pages[0]->index + 1;
/* put any pages we aren't going to use */
for (i = nr_pages; i < found_pages; i++) {
page_cache_release(wdata->pages[i]);
wdata->pages[i] = NULL;
}
nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
end, &index, &next, &done);
/* nothing to write? */
if (nr_pages == 0) {