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authorRyan Ding <ryan.ding@oracle.com>2016-03-25 14:20:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-25 16:37:42 -0700
commit65c4db8c8282cd239f0ba3226cfe59cc9768193c (patch)
tree382f13a751f8d82adc6b3a39951e8948d33365e3
parentb46637d59f1160dee5d8e03498e667ab36c2be04 (diff)
ocfs2: test target page before change it
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. Direct io data will not appear in buffer. The w_target_page member will not be filled by direct io. So avoid to use it when it's NULL. Unlinke buffer io and mmap, direct io will call write_begin with more than 1 page a time. So the target_index is not sufficient to describe the actual data. change it to a range start at target_index, end in end_index. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ocfs2/aops.c32
1 files changed, 26 insertions, 6 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 516ea896f13c..100f7a8a0de1 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1406,12 +1406,13 @@ static void ocfs2_write_failure(struct inode *inode,
to = user_pos + user_len;
struct page *tmppage;
- ocfs2_zero_new_buffers(wc->w_target_page, from, to);
+ if (wc->w_target_page)
+ ocfs2_zero_new_buffers(wc->w_target_page, from, to);
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
- if (page_has_buffers(tmppage)) {
+ if (tmppage && page_has_buffers(tmppage)) {
if (ocfs2_should_order_data(inode))
ocfs2_jbd2_file_inode(wc->w_handle, inode);
@@ -1541,11 +1542,13 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping,
wc->w_num_pages = 1;
start = target_index;
}
+ end_index = (user_pos + user_len - 1) >> PAGE_CACHE_SHIFT;
for(i = 0; i < wc->w_num_pages; i++) {
index = start + i;
- if (index == target_index && mmap_page) {
+ if (index >= target_index && index <= end_index &&
+ wc->w_type == OCFS2_WRITE_MMAP) {
/*
* ocfs2_pagemkwrite() is a little different
* and wants us to directly use the page
@@ -1564,6 +1567,11 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping,
page_cache_get(mmap_page);
wc->w_pages[i] = mmap_page;
wc->w_target_locked = true;
+ } else if (index >= target_index && index <= end_index &&
+ wc->w_type == OCFS2_WRITE_DIRECT) {
+ /* Direct write has no mapping page. */
+ wc->w_pages[i] = NULL;
+ continue;
} else {
wc->w_pages[i] = find_or_create_page(mapping, index,
GFP_NOFS);
@@ -1665,6 +1673,12 @@ static int ocfs2_write_cluster(struct address_space *mapping,
for(i = 0; i < wc->w_num_pages; i++) {
int tmpret;
+ /* This is the direct io target page. */
+ if (wc->w_pages[i] == NULL) {
+ p_blkno++;
+ continue;
+ }
+
tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
wc->w_pages[i], cpos,
user_pos, user_len,
@@ -2266,7 +2280,8 @@ try_again:
ocfs2_free_alloc_context(meta_ac);
success:
- *pagep = wc->w_target_page;
+ if (pagep)
+ *pagep = wc->w_target_page;
*fsdata = wc;
return 0;
out_quota:
@@ -2400,18 +2415,23 @@ int ocfs2_write_end_nolock(struct address_space *mapping,
goto out_write_size;
}
- if (unlikely(copied < len)) {
+ if (unlikely(copied < len) && wc->w_target_page) {
if (!PageUptodate(wc->w_target_page))
copied = 0;
ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
start+len);
}
- flush_dcache_page(wc->w_target_page);
+ if (wc->w_target_page)
+ flush_dcache_page(wc->w_target_page);
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
+ /* This is the direct io target page. */
+ if (tmppage == NULL)
+ continue;
+
if (tmppage == wc->w_target_page) {
from = wc->w_target_from;
to = wc->w_target_to;

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