btrfs: embed extent_changeset::range_changed to the structure

We can embed range_changed to the extent changeset to address following
problems:

- no need to allocate ulist dynamically, we also get rid of the GFP_NOFS
  for free
- fix lack of allocation failure checking in btrfs_qgroup_reserve_data

The stack consuption where extent_changeset is used slightly increases:

before: 16
after: 16 - 8 (for pointer) + 32 (sizeof ulist) = 40

Which is bearable.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9df6ed30de00f00b65ebeba10506ff3dd3173fd6..9140847bfb0cfd008979feb909e06f37f98dc89f 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -144,7 +144,7 @@ static void add_extent_changeset(struct extent_state *state, unsigned bits,
        if (!set && (state->state & bits) == 0)
                return;
        changeset->bytes_changed += state->end - state->start + 1;
-       ret = ulist_add(changeset->range_changed, state->start, state->end,
+       ret = ulist_add(&changeset->range_changed, state->start, state->end,
                        GFP_ATOMIC);
        /* ENOMEM */
        BUG_ON(ret < 0);

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 4551a5b4b8f59e904287d7501badcf63075505f3..270d03be290eec9a53e214634d1aabb0135b6e6d 100644 (file)
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -193,7 +193,7 @@ struct extent_changeset {
        u64 bytes_changed;
 
        /* Changed ranges */
-       struct ulist *range_changed;
+       struct ulist range_changed;
 };
 
 static inline void extent_set_compress_type(unsigned long *bio_flags,

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index b0174431ec8aa5b03845cca300ab451f15eef9c8..627126daf25be4238b8837135328cfba3d3a9475 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2828,7 +2828,7 @@ int btrfs_qgroup_reserve_data(struct inode *inode, u64 start, u64 len)
                return 0;
 
        changeset.bytes_changed = 0;
-       changeset.range_changed = ulist_alloc(GFP_NOFS);
+       ulist_init(&changeset.range_changed);
        ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
                        start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
        trace_btrfs_qgroup_reserve_data(inode, start, len,
@@ -2840,17 +2840,17 @@ int btrfs_qgroup_reserve_data(struct inode *inode, u64 start, u64 len)
        if (ret < 0)
                goto cleanup;
 
-       ulist_free(changeset.range_changed);
+       ulist_fini(&changeset.range_changed);
        return ret;
 
 cleanup:
        /* cleanup already reserved ranges */
        ULIST_ITER_INIT(&uiter);
-       while ((unode = ulist_next(changeset.range_changed, &uiter)))
+       while ((unode = ulist_next(&changeset.range_changed, &uiter)))
                clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
                                 unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL,
                                 GFP_NOFS);
-       ulist_free(changeset.range_changed);
+       ulist_fini(&changeset.range_changed);
        return ret;
 }
 
@@ -2862,10 +2862,7 @@ static int __btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len,
        int ret;
 
        changeset.bytes_changed = 0;
-       changeset.range_changed = ulist_alloc(GFP_NOFS);
-       if (!changeset.range_changed)
-               return -ENOMEM;
-
+       ulist_init(&changeset.range_changed);
        ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start, 
                        start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
        if (ret < 0)
@@ -2878,7 +2875,7 @@ static int __btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len,
        trace_btrfs_qgroup_release_data(inode, start, len,
                                        changeset.bytes_changed, trace_op);
 out:
-       ulist_free(changeset.range_changed);
+       ulist_fini(&changeset.range_changed);
        return ret;
 }
 
@@ -2976,22 +2973,19 @@ void btrfs_qgroup_check_reserved_leak(struct inode *inode)
        int ret;
 
        changeset.bytes_changed = 0;
-       changeset.range_changed = ulist_alloc(GFP_NOFS);
-       if (WARN_ON(!changeset.range_changed))
-               return;
-
+       ulist_init(&changeset.range_changed);
        ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
                        EXTENT_QGROUP_RESERVED, &changeset);
 
        WARN_ON(ret < 0);
        if (WARN_ON(changeset.bytes_changed)) {
                ULIST_ITER_INIT(&iter);
-               while ((unode = ulist_next(changeset.range_changed, &iter))) {
+               while ((unode = ulist_next(&changeset.range_changed, &iter))) {
                        btrfs_warn(BTRFS_I(inode)->root->fs_info,
                                "leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
                                inode->i_ino, unode->val, unode->aux);
                }
                qgroup_free(BTRFS_I(inode)->root, changeset.bytes_changed);
        }
-       ulist_free(changeset.range_changed);
+       ulist_fini(&changeset.range_changed);
 }