We have a BUG_ON() in flush_write_bio() to handle the return value of
submit_one_bio().
Move the BUG_ON() one level up to all its callers.
This patch will introduce temporary variable, @flush_ret to keep code
change minimal in this patch. That variable will be cleaned up when
enhancing the error handling later.
Signed-off-by: Qu Wenruo <w...@suse.com>
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
---
fs/btrfs/extent_io.c | 55 +++++++++++++++++++++++++++++++++-----------
1 file changed, 41 insertions(+), 14 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8a2335713a2d..47a579650a61 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -169,15 +169,28 @@ static int __must_check submit_one_bio(struct bio *bio,
int mirror_num,
return blk_status_to_errno(ret);
}
-static void flush_write_bio(struct extent_page_data *epd)
+/*
+ * A wrapper for submit_one_bio().
+ *
+ * Return 0 if everything is OK.
+ * Return <0 for error.
+ */
+static int __must_check flush_write_bio(struct extent_page_data *epd)
{
- if (epd->bio) {
- int ret;
+ int ret = 0;
+ if (epd->bio) {
ret = submit_one_bio(epd->bio, 0, 0);
- BUG_ON(ret < 0); /* -ENOMEM */
+ /*
+ * Clean up of epd->bio is handled by its endio function.
+ * And endio is either triggered by successful bio execution
+ * or the error handler of submit bio hook.
+ * So at this point, no matter what happened, we don't need
+ * to clean up epd->bio.
+ */
epd->bio = NULL;
}
+ return ret;
}
int __init extent_io_init(void)
@@ -3510,7 +3523,8 @@ lock_extent_buffer_for_io(struct extent_buffer *eb,
if (!btrfs_try_tree_write_lock(eb)) {
flush = 1;
- flush_write_bio(epd);
+ ret = flush_write_bio(epd);
+ BUG_ON(ret < 0);
btrfs_tree_lock(eb);
}
@@ -3519,7 +3533,8 @@ lock_extent_buffer_for_io(struct extent_buffer *eb,
if (!epd->sync_io)
return 0;
if (!flush) {
- flush_write_bio(epd);
+ ret = flush_write_bio(epd);
+ BUG_ON(ret < 0);
flush = 1;
}
while (1) {
@@ -3560,7 +3575,8 @@ lock_extent_buffer_for_io(struct extent_buffer *eb,
if (!trylock_page(p)) {
if (!flush) {
- flush_write_bio(epd);
+ ret = flush_write_bio(epd);
+ BUG_ON(ret < 0);
flush = 1;
}
lock_page(p);
@@ -3751,6 +3767,7 @@ int btree_write_cache_pages(struct address_space *mapping,
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
};
int ret = 0;
+ int flush_ret;
int done = 0;
int nr_to_write_done = 0;
struct pagevec pvec;
@@ -3850,7 +3867,8 @@ int btree_write_cache_pages(struct address_space *mapping,
index = 0;
goto retry;
}
- flush_write_bio(&epd);
+ flush_ret = flush_write_bio(&epd);
+ BUG_ON(flush_ret < 0);
return ret;
}
@@ -3947,7 +3965,8 @@ static int extent_write_cache_pages(struct address_space
*mapping,
* tmpfs file mapping
*/
if (!trylock_page(page)) {
- flush_write_bio(epd);
+ ret = flush_write_bio(epd);
+ BUG_ON(ret < 0);
lock_page(page);
}
@@ -3957,8 +3976,10 @@ static int extent_write_cache_pages(struct address_space
*mapping,
}
if (wbc->sync_mode != WB_SYNC_NONE) {
- if (PageWriteback(page))
- flush_write_bio(epd);
+ if (PageWriteback(page)) {
+ ret = flush_write_bio(epd);
+ BUG_ON(ret < 0);
+ }
wait_on_page_writeback(page);
}
@@ -4019,6 +4040,7 @@ static int extent_write_cache_pages(struct address_space
*mapping,
int extent_write_full_page(struct page *page, struct writeback_control *wbc)
{
int ret;
+ int flush_ret;
struct extent_page_data epd = {
.bio = NULL,
.tree = &BTRFS_I(page->mapping->host)->io_tree,
@@ -4028,7 +4050,8 @@ int extent_write_full_page(struct page *page, struct
writeback_control *wbc)
ret = __extent_writepage(page, wbc, &epd);
- flush_write_bio(&epd);
+ flush_ret = flush_write_bio(&epd);
+ BUG_ON(flush_ret < 0);
return ret;
}
@@ -4036,6 +4059,7 @@ int extent_write_locked_range(struct inode *inode, u64
start, u64 end,
int mode)
{
int ret = 0;
+ int flush_ret;
struct address_space *mapping = inode->i_mapping;
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
struct page *page;
@@ -4068,7 +4092,8 @@ int extent_write_locked_range(struct inode *inode, u64
start, u64 end,
start += PAGE_SIZE;
}
- flush_write_bio(&epd);
+ flush_ret = flush_write_bio(&epd);
+ BUG_ON(flush_ret < 0);
return ret;
}
@@ -4076,6 +4101,7 @@ int extent_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
int ret = 0;
+ int flush_ret;
struct extent_page_data epd = {
.bio = NULL,
.tree = &BTRFS_I(mapping->host)->io_tree,
@@ -4084,7 +4110,8 @@ int extent_writepages(struct address_space *mapping,
};
ret = extent_write_cache_pages(mapping, wbc, &epd);
- flush_write_bio(&epd);
+ flush_ret = flush_write_bio(&epd);
+ BUG_ON(flush_ret < 0);
return ret;
}
--
2.20.1
