btrfs: cleanup extent locking sequence

Code cleanup for better understanding:
Variable needs_unlock to be called extent_locked to show state as
opposed to action. Changed the type to int, to reduce code in the
critical path.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index d3c1725f03e41bd9fb219a0263350f21bcade4f3..4de174b664ffa364734aa6d5e6d29d860be06c1d 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1590,7 +1590,6 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
        int ret = 0;
        bool only_release_metadata = false;
        bool force_page_uptodate = false;
-       bool need_unlock;
 
        nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
                        PAGE_SIZE / (sizeof(struct page *)));
@@ -1613,6 +1612,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                size_t copied;
                size_t dirty_sectors;
                size_t num_sectors;
+               int extents_locked;
 
                WARN_ON(num_pages > nrptrs);
 
@@ -1669,7 +1669,6 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                }
 
                release_bytes = reserve_bytes;
-               need_unlock = false;
 again:
                /*
                 * This is going to setup the pages array with the number of
@@ -1682,16 +1681,15 @@ again:
                if (ret)
                        break;
 
-               ret = lock_and_cleanup_extent_if_need(BTRFS_I(inode), pages,
+               extents_locked = lock_and_cleanup_extent_if_need(
+                               BTRFS_I(inode), pages,
                                num_pages, pos, write_bytes, &lockstart,
                                &lockend, &cached_state);
-               if (ret < 0) {
-                       if (ret == -EAGAIN)
+               if (extents_locked < 0) {
+                       if (extents_locked == -EAGAIN)
                                goto again;
+                       ret = extents_locked;
                        break;
-               } else if (ret > 0) {
-                       need_unlock = true;
-                       ret = 0;
                }
 
                copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
@@ -1756,7 +1754,7 @@ again:
                if (copied > 0)
                        ret = btrfs_dirty_pages(inode, pages, dirty_pages,
                                                pos, copied, NULL);
-               if (need_unlock)
+               if (extents_locked)
                        unlock_extent_cached(&BTRFS_I(inode)->io_tree,
                                             lockstart, lockend, &cached_state,
                                             GFP_NOFS);