move Rust sources to top level, C sources into c_src

[bcachefs-tools-debian] / c_src / include / linux / bvec.h

diff --git a/c_src/include/linux/bvec.h b/c_src/include/linux/bvec.h
new file mode 100644 (file)
index 0000000..5bc68b4
--- /dev/null
+++ b/c_src/include/linux/bvec.h
@@ -0,0 +1,101 @@
+/*
+ * bvec iterator
+ *
+ * Copyright (C) 2001 Ming Lei <ming.lei@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
+ */
+#ifndef __LINUX_BVEC_ITER_H
+#define __LINUX_BVEC_ITER_H
+
+#include <linux/kernel.h>
+#include <linux/bug.h>
+
+/*
+ * was unsigned short, but we might as well be ready for > 64kB I/O pages
+ */
+struct bio_vec {
+       struct page     *bv_page;
+       unsigned int    bv_len;
+       unsigned int    bv_offset;
+};
+
+struct bvec_iter {
+       sector_t                bi_sector;      /* device address in 512 byte
+                                                  sectors */
+       unsigned int            bi_size;        /* residual I/O count */
+
+       unsigned int            bi_idx;         /* current index into bvl_vec */
+
+       unsigned int            bi_bvec_done;   /* number of bytes completed in
+                                                  current bvec */
+};
+
+struct bvec_iter_all {
+       int             idx;
+};
+
+/*
+ * various member access, note that bio_data should of course not be used
+ * on highmem page vectors
+ */
+#define __bvec_iter_bvec(bvec, iter)   (&(bvec)[(iter).bi_idx])
+
+#define bvec_iter_page(bvec, iter)                             \
+       (__bvec_iter_bvec((bvec), (iter))->bv_page)
+
+#define bvec_iter_len(bvec, iter)                              \
+       min((iter).bi_size,                                     \
+           __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
+
+#define bvec_iter_offset(bvec, iter)                           \
+       (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
+
+#define bvec_iter_bvec(bvec, iter)                             \
+((struct bio_vec) {                                            \
+       .bv_page        = bvec_iter_page((bvec), (iter)),       \
+       .bv_len         = bvec_iter_len((bvec), (iter)),        \
+       .bv_offset      = bvec_iter_offset((bvec), (iter)),     \
+})
+
+static inline void bvec_iter_advance(const struct bio_vec *bv,
+                                    struct bvec_iter *iter,
+                                    unsigned bytes)
+{
+       WARN_ONCE(bytes > iter->bi_size,
+                 "Attempted to advance past end of bvec iter\n");
+
+       while (bytes) {
+               unsigned iter_len = bvec_iter_len(bv, *iter);
+               unsigned len = min(bytes, iter_len);
+
+               bytes -= len;
+               iter->bi_size -= len;
+               iter->bi_bvec_done += len;
+
+               if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
+                       iter->bi_bvec_done = 0;
+                       iter->bi_idx++;
+               }
+       }
+}
+
+#define for_each_bvec(bvl, bio_vec, iter, start)                       \
+       for (iter = (start);                                            \
+            (iter).bi_size &&                                          \
+               ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
+            bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
+
+#endif /* __LINUX_BVEC_ITER_H */