Btrfs: Don't use kmap_atomic(..., KM_IRQ0) during checksum verifies

Checksum verification happens in a helper thread, and there is no
need to mess with interrupts.  This switches to kmap() instead.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 3 insertions, 7 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4e57fe68e4b9..cdb701165a05 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1727,7 +1727,6 @@ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
         int ret;
         struct btrfs_root *root = BTRFS_I(inode)->root;
         u32 csum = ~(u32)0;
-        unsigned long flags;
 
         if (PageChecked(page)) {
                 ClearPageChecked(page);
@@ -1749,8 +1748,7 @@ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
         } else {
                 ret = get_state_private(io_tree, start, &private);
         }
-        local_irq_save(flags);
-        kaddr = kmap_atomic(page, KM_IRQ0);
+        kaddr = kmap(page);
         if (ret)
                 goto zeroit;
 
@@ -1759,8 +1757,7 @@ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
         if (csum != private)
                 goto zeroit;
 
-        kunmap_atomic(kaddr, KM_IRQ0);
-        local_irq_restore(flags);
+        kunmap(page);
 good:
         /* if the io failure tree for this inode is non-empty,
          * check to see if we've recovered from a failed IO
@@ -1775,8 +1772,7 @@ zeroit:
                (unsigned long long)private);
         memset(kaddr + offset, 1, end - start + 1);
         flush_dcache_page(page);
-        kunmap_atomic(kaddr, KM_IRQ0);
-        local_irq_restore(flags);
+        kunmap(page);
         if (private == 0)
                 return 0;
         return -EIO;