Merge tag 'for-5.5-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...

Pull btrfs fixes from David Sterba:
 "A few fixes for btrfs:

   - blkcg accounting problem with compression that could stall writes

   - setting up blkcg bio for compression crashes due to NULL bdev
     pointer

   - fix possible infinite loop in writeback for nocow files (here
     possible means almost impossible, 13 things that need to happen to
     trigger it)"

* tag 'for-5.5-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix infinite loop during nocow writeback due to race
  btrfs: fix compressed write bio blkcg attribution
  btrfs: punt all bios created in btrfs_submit_compressed_write()

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index ee834ef..43e1660 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -447,7 +447,7 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 
        if (blkcg_css) {
                bio->bi_opf |= REQ_CGROUP_PUNT;
-               bio_associate_blkg_from_css(bio, blkcg_css);
+               kthread_associate_blkcg(blkcg_css);
        }
        refcount_set(&cb->pending_bios, 1);
 
@@ -491,6 +491,8 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
                        bio->bi_opf = REQ_OP_WRITE | write_flags;
                        bio->bi_private = cb;
                        bio->bi_end_io = end_compressed_bio_write;
+                       if (blkcg_css)
+                               bio->bi_opf |= REQ_CGROUP_PUNT;
                        bio_add_page(bio, page, PAGE_SIZE, 0);
                }
                if (bytes_left < PAGE_SIZE) {
@@ -517,6 +519,9 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
                bio_endio(bio);
        }
 
+       if (blkcg_css)
+               kthread_associate_blkcg(NULL);
+
        return 0;
 }
 

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e3c7664..5509c41 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1479,10 +1479,10 @@ next_slot:
                        disk_num_bytes =
                                btrfs_file_extent_disk_num_bytes(leaf, fi);
                        /*
-                        * If extent we got ends before our range starts, skip
-                        * to next extent
+                        * If the extent we got ends before our current offset,
+                        * skip to the next extent.
                         */
-                       if (extent_end <= start) {
+                       if (extent_end <= cur_offset) {
                                path->slots[0]++;
                                goto next_slot;
                        }