diff options
| -rw-r--r-- | fs/btrfs/compression.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 0e1561cc9578..0d445c815ca2 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -1222,6 +1222,14 @@ int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, return 1; } +static bool sample_repeated_patterns(struct heuristic_ws *ws) +{ + const u32 half_of_sample = ws->sample_size / 2; + const u8 *data = ws->sample; + + return memcmp(&data[0], &data[half_of_sample], half_of_sample) == 0; +} + static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end, struct heuristic_ws *ws) { @@ -1301,6 +1309,11 @@ int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end) heuristic_collect_sample(inode, start, end, ws); + if (sample_repeated_patterns(ws)) { + ret = 1; + goto out; + } + memset(ws->bucket, 0, sizeof(*ws->bucket)*BUCKET_SIZE); for (i = 0; i < ws->sample_size; i++) { @@ -1308,8 +1321,8 @@ int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end) ws->bucket[byte].count++; } +out: __free_workspace(0, ws_list, true); - return ret; } |