btrfs: defrag: make readahead state allocation failure non-fatal

All sorts of readahead errors are not considered fatal. We can continue
defragmentation without it, with some potential slow down, which will
last only for the current inode.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4d1b07b815495a71b64fdd9b854950ae2636bfa0..496e873b14de4a8e3257fe75fb75dcaf8f2ef588 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1273,14 +1273,14 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
                extent_thresh = SZ_256K;
 
        /*
-        * if we were not given a file, allocate a readahead
-        * context
+        * If we were not given a file, allocate a readahead context. As
+        * readahead is just an optimization, defrag will work without it so
+        * we don't error out.
         */
        if (!file) {
                ra = kzalloc(sizeof(*ra), GFP_KERNEL);
-               if (!ra)
-                       return -ENOMEM;
-               file_ra_state_init(ra, inode->i_mapping);
+               if (ra)
+                       file_ra_state_init(ra, inode->i_mapping);
        } else {
                ra = &file->f_ra;
        }
@@ -1363,8 +1363,9 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 
                if (i + cluster > ra_index) {
                        ra_index = max(i, ra_index);
-                       btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
-                                      cluster);
+                       if (ra)
+                               btrfs_force_ra(inode->i_mapping, ra, file,
+                                               ra_index, cluster);
                        ra_index += cluster;
                }