erofs-utils: lib: wrap up zeropadding calculation

Use a simple helper instead of open-coding.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240604084015.2291157-1-hsiangkao@linux.alibaba.com

diff --git a/lib/decompress.c b/lib/decompress.c
index 58ce7e51c34d618d4eea758a317e4652631833d3..e65b924193863cb18c8c6003199d1c563091b619 100644 (file)
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -9,6 +9,15 @@
 #include "erofs/err.h"
 #include "erofs/print.h"
 
+static unsigned int z_erofs_fixup_insize(const u8 *padbuf, unsigned int padbufsize)
+{
+       unsigned int inputmargin;
+
+       for (inputmargin = 0; inputmargin < padbufsize &&
+            !padbuf[inputmargin]; ++inputmargin);
+       return inputmargin;
+}
+
 #ifdef HAVE_LIBZSTD
 #include <zstd.h>
 #include <zstd_errors.h>
@@ -16,7 +25,6 @@
 /* also a very preliminary userspace version */
 static int z_erofs_decompress_zstd(struct z_erofs_decompress_req *rq)
 {
-       struct erofs_sb_info *sbi = rq->sbi;
        int ret = 0;
        char *dest = rq->out;
        char *src = rq->in;
@@ -24,10 +32,7 @@ static int z_erofs_decompress_zstd(struct z_erofs_decompress_req *rq)
        unsigned int inputmargin = 0;
        unsigned long long total;
 
-       while (!src[inputmargin & (erofs_blksiz(sbi) - 1)])
-               if (!(++inputmargin & (erofs_blksiz(sbi) - 1)))
-                       break;
-
+       inputmargin = z_erofs_fixup_insize((u8 *)src, rq->inputsize);
        if (inputmargin >= rq->inputsize)
                return -EFSCORRUPTED;
 
@@ -78,19 +83,15 @@ out:
 
 static int z_erofs_decompress_deflate(struct z_erofs_decompress_req *rq)
 {
-       struct erofs_sb_info *sbi = rq->sbi;
        u8 *dest = (u8 *)rq->out;
        u8 *src = (u8 *)rq->in;
        u8 *buff = NULL;
        size_t actual_out;
-       unsigned int inputmargin = 0;
+       unsigned int inputmargin;
        struct libdeflate_decompressor *inf;
        enum libdeflate_result ret;
 
-       while (!src[inputmargin & (erofs_blksiz(sbi) - 1)])
-               if (!(++inputmargin & (erofs_blksiz(sbi) - 1)))
-                       break;
-
+       inputmargin = z_erofs_fixup_insize(src, rq->inputsize);
        if (inputmargin >= rq->inputsize)
                return -EFSCORRUPTED;
 
@@ -160,18 +161,14 @@ static int zerr(int ret)
 
 static int z_erofs_decompress_deflate(struct z_erofs_decompress_req *rq)
 {
-       struct erofs_sb_info *sbi = rq->sbi;
        u8 *dest = (u8 *)rq->out;
        u8 *src = (u8 *)rq->in;
        u8 *buff = NULL;
-       unsigned int inputmargin = 0;
+       unsigned int inputmargin;
        z_stream strm;
        int ret;
 
-       while (!src[inputmargin & (erofs_blksiz(sbi) - 1)])
-               if (!(++inputmargin & (erofs_blksiz(sbi) - 1)))
-                       break;
-
+       inputmargin = z_erofs_fixup_insize(src, rq->inputsize);
        if (inputmargin >= rq->inputsize)
                return -EFSCORRUPTED;
 
@@ -225,18 +222,14 @@ out_inflate_end:
 static int z_erofs_decompress_lzma(struct z_erofs_decompress_req *rq)
 {
        int ret = 0;
-       struct erofs_sb_info *sbi = rq->sbi;
        u8 *dest = (u8 *)rq->out;
        u8 *src = (u8 *)rq->in;
        u8 *buff = NULL;
-       unsigned int inputmargin = 0;
+       unsigned int inputmargin;
        lzma_stream strm;
        lzma_ret ret2;
 
-       while (!src[inputmargin & (erofs_blksiz(sbi) - 1)])
-               if (!(++inputmargin & (erofs_blksiz(sbi) - 1)))
-                       break;
-
+       inputmargin = z_erofs_fixup_insize(src, rq->inputsize);
        if (inputmargin >= rq->inputsize)
                return -EFSCORRUPTED;
 
@@ -297,12 +290,9 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
        if (erofs_sb_has_lz4_0padding(sbi)) {
                support_0padding = true;
 
-               while (!src[inputmargin & (erofs_blksiz(sbi) - 1)])
-                       if (!(++inputmargin & (erofs_blksiz(sbi) - 1)))
-                               break;
-
+               inputmargin = z_erofs_fixup_insize((u8 *)src, rq->inputsize);
                if (inputmargin >= rq->inputsize)
-                       return -EIO;
+                       return -EFSCORRUPTED;
        }
 
        if (rq->decodedskip) {