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-rw-r--r--fs/ubifs/compress.c6
-rw-r--r--fs/ubifs/ubifs-media.h7
2 files changed, 10 insertions, 3 deletions
diff --git a/fs/ubifs/compress.c b/fs/ubifs/compress.c
index a0ada596b17..6414d50780e 100644
--- a/fs/ubifs/compress.c
+++ b/fs/ubifs/compress.c
@@ -119,10 +119,10 @@ void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
}
/*
- * Presently, we just require that compression results in less data,
- * rather than any defined minimum compression ratio or amount.
+ * If the data compressed only slightly, it is better to leave it
+ * uncompressed to improve read speed.
*/
- if (ALIGN(*out_len, 8) >= ALIGN(in_len, 8))
+ if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF)
goto no_compr;
return;
diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h
index 0b378042a3a..b25fc36cf72 100644
--- a/fs/ubifs/ubifs-media.h
+++ b/fs/ubifs/ubifs-media.h
@@ -51,6 +51,13 @@
*/
#define UBIFS_MIN_COMPR_LEN 128
+/*
+ * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
+ * shorter than uncompressed data length, UBIFS preferes to leave this data
+ * node uncompress, because it'll be read faster.
+ */
+#define UBIFS_MIN_COMPRESS_DIFF 64
+
/* Root inode number */
#define UBIFS_ROOT_INO 1