btrfs: add an extra wait mode to read_extent_buffer_pages
read_extent_buffer_pages currently has two modes, either trigger a read
without waiting for anything, or wait for the I/O to finish. The former
also bails when it's unable to lock the page. This patch now adds an
additional parameter to allow it to block on page lock, but don't wait
for completion.
Changes v5:
- merge the 2 wait parameters into one and define WAIT_NONE, WAIT_COMPLETE and
WAIT_PAGE_LOCK
Change v6:
- fix bug introduced in v5
Signed-off-by: Arne Jansen <sensille@gmx.net>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d418164..823028e 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3349,8 +3349,7 @@
}
int read_extent_buffer_pages(struct extent_io_tree *tree,
- struct extent_buffer *eb,
- u64 start, int wait,
+ struct extent_buffer *eb, u64 start, int wait,
get_extent_t *get_extent, int mirror_num)
{
unsigned long i;
@@ -3386,7 +3385,7 @@
num_pages = num_extent_pages(eb->start, eb->len);
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
- if (!wait) {
+ if (wait == WAIT_NONE) {
if (!trylock_page(page))
goto unlock_exit;
} else {
@@ -3430,7 +3429,7 @@
if (bio)
submit_one_bio(READ, bio, mirror_num, bio_flags);
- if (ret || !wait)
+ if (ret || wait != WAIT_COMPLETE)
return ret;
for (i = start_i; i < num_pages; i++) {