btrfs: Allow to specify compress method when defrag

Update defrag ioctl, so one can choose lzo or zlib when turning
on compression in defrag operation.

Changelog:

v1 -> v2
- Add incompability flag.
- Fix to check invalid compress type.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

2 files changed, 26 insertions, 2 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8cb86d4d763c..b6985d33eede 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -638,9 +638,11 @@ static int btrfs_defrag_file(struct file *file,
         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
         struct btrfs_ordered_extent *ordered;
         struct page *page;
+        struct btrfs_super_block *disk_super;
         unsigned long last_index;
         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
         unsigned long total_read = 0;
+        u64 features;
         u64 page_start;
         u64 page_end;
         u64 last_len = 0;
@@ -648,6 +650,14 @@ static int btrfs_defrag_file(struct file *file,
         u64 defrag_end = 0;
         unsigned long i;
         int ret;
+        int compress_type = BTRFS_COMPRESS_ZLIB;
+
+        if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
+                if (range->compress_type > BTRFS_COMPRESS_TYPES)
+                        return -EINVAL;
+                if (range->compress_type)
+                        compress_type = range->compress_type;
+        }
 
         if (inode->i_size == 0)
                 return 0;
@@ -683,7 +693,7 @@ static int btrfs_defrag_file(struct file *file,
                 total_read++;
                 mutex_lock(&inode->i_mutex);
                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
-                        BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_ZLIB;
+                        BTRFS_I(inode)->force_compress = compress_type;
 
                 ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
                 if (ret)
@@ -785,6 +795,13 @@ loop_unlock:
                 mutex_unlock(&inode->i_mutex);
         }
 
+        disk_super = &root->fs_info->super_copy;
+        features = btrfs_super_incompat_flags(disk_super);
+        if (range->compress_type == BTRFS_COMPRESS_LZO) {
+                features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
+                btrfs_set_super_incompat_flags(disk_super, features);
+        }
+
         return 0;
 
 err_reservations:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index c344d12c646b..24d0f4628240 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -133,8 +133,15 @@ struct btrfs_ioctl_defrag_range_args {
          */
         __u32 extent_thresh;
 
+        /*
+         * which compression method to use if turning on compression
+         * for this defrag operation.  If unspecified, zlib will
+         * be used
+         */
+        __u32 compress_type;
+
         /* spare for later */
-        __u32 unused[5];
+        __u32 unused[4];
 };
 
 struct btrfs_ioctl_space_info {