diff options
authorJosef Bacik <jbacik@fusionio.com>2013-08-30 14:38:49 -0400
committerChris Mason <chris.mason@fusionio.com>2013-09-21 11:05:24 -0400
commit573aecafca1cf7a974231b759197a1aebcf39c2a (patch)
parenta482039889b85c45fc9616e65d560db7a35d4f54 (diff)
Btrfs: actually limit the size of delalloc range
So forever we have had this thing to limit the amount of delalloc pages we'll setup to be written out to 128mb. This is because we have to lock all the pages in this range, so anything above this gets a bit unweildly, and also without a limit we'll happily allocate gigantic chunks of disk space. Turns out our check for this wasn't quite right, we wouldn't actually limit the chunk we wanted to write out, we'd just stop looking for more space after we went over the limit. So if you do a giant 20gb dd on my box with lots of ram I could get 2gig extents. This is fine normally, except when you go to relocate these extents and we can't find enough space to relocate these moster extents, since we have to be able to allocate exactly the same sized extent to move it around. So fix this by actually enforcing the limit. With this patch I'm no longer seeing giant 1.5gb extents. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 09582b81640c..c09a40db53db 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1481,10 +1481,12 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
*end = state->end;
cur_start = state->end + 1;
node = rb_next(node);
- if (!node)
- break;
total_bytes += state->end - state->start + 1;
- if (total_bytes >= max_bytes)
+ if (total_bytes >= max_bytes) {
+ *end = *start + max_bytes - 1;
+ break;
+ }
+ if (!node)

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