Re: [v5 PATCH 14/14] ubifs: Pass folios to acomp

Zhihao Cheng
2025-03-19T09:45:03Z

在 2025/3/15 18:30, Herbert Xu 写道:
> As the acomp interface supports folios, use that instead of mapping
> the data in ubifs.
>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> ---
> fs/ubifs/compress.c | 106 +++++++++++++++++++++++++++++++++++++++++++-
> fs/ubifs/file.c | 74 +++++++++++--------------------
> fs/ubifs/journal.c | 9 ++--
> fs/ubifs/ubifs.h | 11 ++++-
> 4 files changed, 145 insertions(+), 55 deletions(-)

Tested-by: Zhihao Cheng <chengzhihao1@huawei.com> # For xfstests

>
> diff --git a/fs/ubifs/compress.c b/fs/ubifs/compress.c
> index a241ba01c9a8..ea6f06adcd43 100644
> --- a/fs/ubifs/compress.c
> +++ b/fs/ubifs/compress.c
> @@ -16,6 +16,7 @@
> */
>
> #include <crypto/acompress.h>
> +#include <linux/highmem.h>
> #include "ubifs.h"
>
> /* Fake description object for the "none" compressor */
> @@ -126,7 +127,7 @@ void ubifs_compress(const struct ubifs_info *c, const void *in_buf,
> {
> ACOMP_REQUEST_ALLOC(req, compr->cc, GFP_NOFS | __GFP_NOWARN);
>
> - acomp_request_set_src_nondma(req, in_buf, in_len);
> + acomp_request_set_src_dma(req, in_buf, in_len);

Why not merging it into patch 13?
> err = ubifs_compress_req(c, req, out_buf, out_len, compr->name);
> }
>
> @@ -141,6 +142,58 @@ void ubifs_compress(const struct ubifs_info *c, const void *in_buf,
> *compr_type = UBIFS_COMPR_NONE;
> }
>
> +/**
> + * ubifs_compress_folio - compress folio.
> + * @c: UBIFS file-system description object
> + * @in_folio: data to compress
> + * @in_offset: offset into @in_folio
> + * @in_len: length of the data to compress
> + * @out_buf: output buffer where compressed data should be stored
> + * @out_len: output buffer length is returned here
> + * @compr_type: type of compression to use on enter, actually used compression
> + * type on exit
> + *
> + * This function compresses input folio @in_folio of length @in_len and
> + * stores the result in the output buffer @out_buf and the resulting length
> + * in @out_len. If the input buffer does not compress, it is just copied
> + * to the @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE
> + * or if compression error occurred.
> + *
> + * Note, if the input buffer was not compressed, it is copied to the output
> + * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
> + */
> +void ubifs_compress_folio(const struct ubifs_info *c, struct folio *in_folio,
> + size_t in_offset, int in_len, void *out_buf,
> + int *out_len, int *compr_type)
> +{
> + int err;
> + struct ubifs_compressor *compr = ubifs_compressors[*compr_type];
> +
> + if (*compr_type == UBIFS_COMPR_NONE)
> + goto no_compr;
> +
> + /* If the input data is small, do not even try to compress it */
> + if (in_len < UBIFS_MIN_COMPR_LEN)
> + goto no_compr;
> +
> + {
> + ACOMP_REQUEST_ALLOC(req, compr->cc, GFP_NOFS | __GFP_NOWARN);
> +
> + acomp_request_set_src_folio(req, in_folio, in_offset, in_len);
> + err = ubifs_compress_req(c, req, out_buf, out_len, compr->name);
> + }
> +
> + if (err)
> + goto no_compr;
> +
> + return;
> +
> +no_compr:
> + memcpy_from_folio(out_buf, in_folio, in_offset, in_len);
> + *out_len = in_len;
> + *compr_type = UBIFS_COMPR_NONE;
> +}
> +
> static int ubifs_decompress_req(const struct ubifs_info *c,
> struct acomp_req *req,
> const void *in_buf, int in_len, int *out_len,
> @@ -205,7 +258,56 @@ int ubifs_decompress(const struct ubifs_info *c, const void *in_buf,
> {
> ACOMP_REQUEST_ALLOC(req, compr->cc, GFP_NOFS | __GFP_NOWARN);
>
> - acomp_request_set_dst_nondma(req, out_buf, *out_len);
> + acomp_request_set_dst_dma(req, out_buf, *out_len);

Same as the suggestion above.
> + return ubifs_decompress_req(c, req, in_buf, in_len, out_len,
> + compr->name);
> + }
> +}
> +
> +/**
> + * ubifs_decompress_folio - decompress folio.
> + * @c: UBIFS file-system description object
> + * @in_buf: data to decompress
> + * @in_len: length of the data to decompress
> + * @out_folio: output folio where decompressed data should
> + * @out_offset: offset into @out_folio
> + * @out_len: output length is returned here
> + * @compr_type: type of compression
> + *
> + * This function decompresses data from buffer @in_buf into folio
> + * @out_folio. The length of the uncompressed data is returned in
> + * @out_len. This functions returns %0 on success or a negative error
> + * code on failure.
> + */
> +int ubifs_decompress_folio(const struct ubifs_info *c, const void *in_buf,
> + int in_len, struct folio *out_folio,
> + size_t out_offset, int *out_len, int compr_type)
> +{
> + struct ubifs_compressor *compr;
> +
> + if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
> + ubifs_err(c, "invalid compression type %d", compr_type);
> + return -EINVAL;
> + }
> +
> + compr = ubifs_compressors[compr_type];
> +
> + if (unlikely(!compr->capi_name)) {
> + ubifs_err(c, "%s compression is not compiled in", compr->name);
> + return -EINVAL;
> + }
> +
> + if (compr_type == UBIFS_COMPR_NONE) {
> + memcpy_to_folio(out_folio, out_offset, in_buf, in_len);
> + *out_len = in_len;
> + return 0;
> + }
> +
> + {
> + ACOMP_REQUEST_ALLOC(req, compr->cc, GFP_NOFS | __GFP_NOWARN);
> +
> + acomp_request_set_dst_folio(req, out_folio, out_offset,
> + *out_len);
> return ubifs_decompress_req(c, req, in_buf, in_len, out_len,
> compr->name);
> }