From: Chao Yu yuchao0@huawei.com
[ Upstream commit f6644143c63f2eac88973f7fea087582579b0189 ]
Commonly, in order to handle lz4 worst compress case, caller should allocate buffer with size of LZ4_compressBound(inputsize) for target compressed data storing, however in this case, if caller didn't allocate enough space, lz4 compressor still can handle output buffer budget properly, and end up compressing when left space in output buffer is not enough.
So we don't have to allocate buffer with size for worst case, then we can avoid 2 * 4KB size intermediate buffer allocation when log_cluster_size is 2, and avoid unnecessary compressing work of compressor if we can not save at least 4KB space.
Suggested-by: Daeho Jeong daehojeong@google.com Signed-off-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/compress.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index df7b2d15eacd..c05801758a35 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -236,7 +236,12 @@ static int lz4_init_compress_ctx(struct compress_ctx *cc) if (!cc->private) return -ENOMEM;
- cc->clen = LZ4_compressBound(PAGE_SIZE << cc->log_cluster_size); + /* + * we do not change cc->clen to LZ4_compressBound(inputsize) to + * adapt worst compress case, because lz4 compressor can handle + * output budget properly. + */ + cc->clen = cc->rlen - PAGE_SIZE - COMPRESS_HEADER_SIZE; return 0; }
@@ -252,11 +257,9 @@ static int lz4_compress_pages(struct compress_ctx *cc)
len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen, cc->clen, cc->private); - if (!len) { - printk_ratelimited("%sF2FS-fs (%s): lz4 compress failed\n", - KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id); - return -EIO; - } + if (!len) + return -EAGAIN; + cc->clen = len; return 0; }