diff mbox

[v6] Btrfs: compression must free at least one sector size

Message ID 20170606114115.21602-1-nefelim4ag@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Timofey Titovets June 6, 2017, 11:41 a.m. UTC
Btrfs already skip store of data where compression didn't
free at least one byte. Let's make logic better and make check
that compression free at least one sector size
because in another case it useless to store this data compressed

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Cc: David Sterba <dsterba@suse.cz>
---
 fs/btrfs/inode.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--
2.13.0
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Comments

David Sterba June 13, 2017, 1:45 p.m. UTC | #1
On Tue, Jun 06, 2017 at 02:41:15PM +0300, Timofey Titovets wrote:
> Btrfs already skip store of data where compression didn't
> free at least one byte. Let's make logic better and make check
> that compression free at least one sector size
> because in another case it useless to store this data compressed
> 
> Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

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

I've updated the changelog a bit.
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diff mbox

Patch

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 17cbe930..7646f46b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -609,11 +609,10 @@  static noinline void compress_file_range(struct inode *inode,
 		/*
 		 * one last check to make sure the compression is really a
 		 * win, compare the page count read with the blocks on disk
+		 * compression must free at least one sector size
 		 */
 		total_in = ALIGN(total_in, PAGE_SIZE);
-		if (total_compressed >= total_in) {
-			will_compress = 0;
-		} else {
+		if (total_compressed + blocksize <= total_in) {
 			num_bytes = total_in;
 			*num_added += 1;