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-rw-r--r--fs/bcachefs/printbuf.c447
1 files changed, 447 insertions, 0 deletions
diff --git a/fs/bcachefs/printbuf.c b/fs/bcachefs/printbuf.c
new file mode 100644
index 0000000000..accf246c32
--- /dev/null
+++ b/fs/bcachefs/printbuf.c
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: LGPL-2.1+
+/* Copyright (C) 2022 Kent Overstreet */
+
+#include <linux/bitmap.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string_helpers.h>
+
+#include "printbuf.h"
+
+static inline unsigned printbuf_linelen(struct printbuf *buf)
+{
+ return buf->pos - buf->last_newline;
+}
+
+int bch2_printbuf_make_room(struct printbuf *out, unsigned extra)
+{
+ unsigned new_size;
+ char *buf;
+
+ if (!out->heap_allocated)
+ return 0;
+
+ /* Reserved space for terminating nul: */
+ extra += 1;
+
+ if (out->pos + extra < out->size)
+ return 0;
+
+ new_size = roundup_pow_of_two(out->size + extra);
+
+ /*
+ * Note: output buffer must be freeable with kfree(), it's not required
+ * that the user use printbuf_exit().
+ */
+ buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT);
+
+ if (!buf) {
+ out->allocation_failure = true;
+ return -ENOMEM;
+ }
+
+ out->buf = buf;
+ out->size = new_size;
+ return 0;
+}
+
+void bch2_prt_vprintf(struct printbuf *out, const char *fmt, va_list args)
+{
+ int len;
+
+ do {
+ va_list args2;
+
+ va_copy(args2, args);
+ len = vsnprintf(out->buf + out->pos, printbuf_remaining(out), fmt, args2);
+ } while (len + 1 >= printbuf_remaining(out) &&
+ !bch2_printbuf_make_room(out, len + 1));
+
+ len = min_t(size_t, len,
+ printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0);
+ out->pos += len;
+}
+
+void bch2_prt_printf(struct printbuf *out, const char *fmt, ...)
+{
+ va_list args;
+ int len;
+
+ do {
+ va_start(args, fmt);
+ len = vsnprintf(out->buf + out->pos, printbuf_remaining(out), fmt, args);
+ va_end(args);
+ } while (len + 1 >= printbuf_remaining(out) &&
+ !bch2_printbuf_make_room(out, len + 1));
+
+ len = min_t(size_t, len,
+ printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0);
+ out->pos += len;
+}
+
+/**
+ * bch2_printbuf_str() - returns printbuf's buf as a C string, guaranteed to be
+ * null terminated
+ * @buf: printbuf to terminate
+ * Returns: Printbuf contents, as a nul terminated C string
+ */
+const char *bch2_printbuf_str(const struct printbuf *buf)
+{
+ /*
+ * If we've written to a printbuf then it's guaranteed to be a null
+ * terminated string - but if we haven't, then we might not have
+ * allocated a buffer at all:
+ */
+ return buf->pos
+ ? buf->buf
+ : "";
+}
+
+/**
+ * bch2_printbuf_exit() - exit a printbuf, freeing memory it owns and poisoning it
+ * against accidental use.
+ * @buf: printbuf to exit
+ */
+void bch2_printbuf_exit(struct printbuf *buf)
+{
+ if (buf->heap_allocated) {
+ kfree(buf->buf);
+ buf->buf = ERR_PTR(-EINTR); /* poison value */
+ }
+}
+
+void bch2_printbuf_tabstops_reset(struct printbuf *buf)
+{
+ buf->nr_tabstops = 0;
+}
+
+void bch2_printbuf_tabstop_pop(struct printbuf *buf)
+{
+ if (buf->nr_tabstops)
+ --buf->nr_tabstops;
+}
+
+/*
+ * bch2_printbuf_tabstop_set() - add a tabstop, n spaces from the previous tabstop
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces from previous tabpstop
+ *
+ * In the future this function may allocate memory if setting more than
+ * PRINTBUF_INLINE_TABSTOPS or setting tabstops more than 255 spaces from start
+ * of line.
+ */
+int bch2_printbuf_tabstop_push(struct printbuf *buf, unsigned spaces)
+{
+ unsigned prev_tabstop = buf->nr_tabstops
+ ? buf->_tabstops[buf->nr_tabstops - 1]
+ : 0;
+
+ if (WARN_ON(buf->nr_tabstops >= ARRAY_SIZE(buf->_tabstops)))
+ return -EINVAL;
+
+ buf->_tabstops[buf->nr_tabstops++] = prev_tabstop + spaces;
+ buf->has_indent_or_tabstops = true;
+ return 0;
+}
+
+/**
+ * bch2_printbuf_indent_add() - add to the current indent level
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces to add to the current indent level
+ *
+ * Subsequent lines, and the current line if the output position is at the start
+ * of the current line, will be indented by @spaces more spaces.
+ */
+void bch2_printbuf_indent_add(struct printbuf *buf, unsigned spaces)
+{
+ if (WARN_ON_ONCE(buf->indent + spaces < buf->indent))
+ spaces = 0;
+
+ buf->indent += spaces;
+ prt_chars(buf, ' ', spaces);
+
+ buf->has_indent_or_tabstops = true;
+}
+
+/**
+ * bch2_printbuf_indent_sub() - subtract from the current indent level
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces to subtract from the current indent level
+ *
+ * Subsequent lines, and the current line if the output position is at the start
+ * of the current line, will be indented by @spaces less spaces.
+ */
+void bch2_printbuf_indent_sub(struct printbuf *buf, unsigned spaces)
+{
+ if (WARN_ON_ONCE(spaces > buf->indent))
+ spaces = buf->indent;
+
+ if (buf->last_newline + buf->indent == buf->pos) {
+ buf->pos -= spaces;
+ printbuf_nul_terminate(buf);
+ }
+ buf->indent -= spaces;
+
+ if (!buf->indent && !buf->nr_tabstops)
+ buf->has_indent_or_tabstops = false;
+}
+
+void bch2_prt_newline(struct printbuf *buf)
+{
+ unsigned i;
+
+ bch2_printbuf_make_room(buf, 1 + buf->indent);
+
+ __prt_char(buf, '\n');
+
+ buf->last_newline = buf->pos;
+
+ for (i = 0; i < buf->indent; i++)
+ __prt_char(buf, ' ');
+
+ printbuf_nul_terminate(buf);
+
+ buf->last_field = buf->pos;
+ buf->cur_tabstop = 0;
+}
+
+/*
+ * Returns spaces from start of line, if set, or 0 if unset:
+ */
+static inline unsigned cur_tabstop(struct printbuf *buf)
+{
+ return buf->cur_tabstop < buf->nr_tabstops
+ ? buf->_tabstops[buf->cur_tabstop]
+ : 0;
+}
+
+static void __prt_tab(struct printbuf *out)
+{
+ int spaces = max_t(int, 0, cur_tabstop(out) - printbuf_linelen(out));
+
+ prt_chars(out, ' ', spaces);
+
+ out->last_field = out->pos;
+ out->cur_tabstop++;
+}
+
+/**
+ * bch2_prt_tab() - Advance printbuf to the next tabstop
+ * @out: printbuf to control
+ *
+ * Advance output to the next tabstop by printing spaces.
+ */
+void bch2_prt_tab(struct printbuf *out)
+{
+ if (WARN_ON(!cur_tabstop(out)))
+ return;
+
+ __prt_tab(out);
+}
+
+static void __prt_tab_rjust(struct printbuf *buf)
+{
+ unsigned move = buf->pos - buf->last_field;
+ int pad = (int) cur_tabstop(buf) - (int) printbuf_linelen(buf);
+
+ if (pad > 0) {
+ bch2_printbuf_make_room(buf, pad);
+
+ if (buf->last_field + pad < buf->size)
+ memmove(buf->buf + buf->last_field + pad,
+ buf->buf + buf->last_field,
+ min(move, buf->size - 1 - buf->last_field - pad));
+
+ if (buf->last_field < buf->size)
+ memset(buf->buf + buf->last_field, ' ',
+ min((unsigned) pad, buf->size - buf->last_field));
+
+ buf->pos += pad;
+ printbuf_nul_terminate(buf);
+ }
+
+ buf->last_field = buf->pos;
+ buf->cur_tabstop++;
+}
+
+/**
+ * bch2_prt_tab_rjust - Advance printbuf to the next tabstop, right justifying
+ * previous output
+ *
+ * @buf: printbuf to control
+ *
+ * Advance output to the next tabstop by inserting spaces immediately after the
+ * previous tabstop, right justifying previously outputted text.
+ */
+void bch2_prt_tab_rjust(struct printbuf *buf)
+{
+ if (WARN_ON(!cur_tabstop(buf)))
+ return;
+
+ __prt_tab_rjust(buf);
+}
+
+/**
+ * bch2_prt_bytes_indented() - Print an array of chars, handling embedded control characters
+ *
+ * @out: output printbuf
+ * @str: string to print
+ * @count: number of bytes to print
+ *
+ * The following contol characters are handled as so:
+ * \n: prt_newline newline that obeys current indent level
+ * \t: prt_tab advance to next tabstop
+ * \r: prt_tab_rjust advance to next tabstop, with right justification
+ */
+void bch2_prt_bytes_indented(struct printbuf *out, const char *str, unsigned count)
+{
+ const char *unprinted_start = str;
+ const char *end = str + count;
+
+ if (!out->has_indent_or_tabstops || out->suppress_indent_tabstop_handling) {
+ prt_bytes(out, str, count);
+ return;
+ }
+
+ while (str != end) {
+ switch (*str) {
+ case '\n':
+ prt_bytes(out, unprinted_start, str - unprinted_start);
+ unprinted_start = str + 1;
+ bch2_prt_newline(out);
+ break;
+ case '\t':
+ if (likely(cur_tabstop(out))) {
+ prt_bytes(out, unprinted_start, str - unprinted_start);
+ unprinted_start = str + 1;
+ __prt_tab(out);
+ }
+ break;
+ case '\r':
+ if (likely(cur_tabstop(out))) {
+ prt_bytes(out, unprinted_start, str - unprinted_start);
+ unprinted_start = str + 1;
+ __prt_tab_rjust(out);
+ }
+ break;
+ }
+
+ str++;
+ }
+
+ prt_bytes(out, unprinted_start, str - unprinted_start);
+}
+
+/**
+ * bch2_prt_human_readable_u64() - Print out a u64 in human readable units
+ * @out: output printbuf
+ * @v: integer to print
+ *
+ * Units of 2^10 (default) or 10^3 are controlled via @out->si_units
+ */
+void bch2_prt_human_readable_u64(struct printbuf *out, u64 v)
+{
+ bch2_printbuf_make_room(out, 10);
+ out->pos += string_get_size(v, 1, !out->si_units,
+ out->buf + out->pos,
+ printbuf_remaining_size(out));
+}
+
+/**
+ * bch2_prt_human_readable_s64() - Print out a s64 in human readable units
+ * @out: output printbuf
+ * @v: integer to print
+ *
+ * Units of 2^10 (default) or 10^3 are controlled via @out->si_units
+ */
+void bch2_prt_human_readable_s64(struct printbuf *out, s64 v)
+{
+ if (v < 0)
+ prt_char(out, '-');
+ bch2_prt_human_readable_u64(out, abs(v));
+}
+
+/**
+ * bch2_prt_units_u64() - Print out a u64 according to printbuf unit options
+ * @out: output printbuf
+ * @v: integer to print
+ *
+ * Units are either raw (default), or human reabable units (controlled via
+ * @buf->human_readable_units)
+ */
+void bch2_prt_units_u64(struct printbuf *out, u64 v)
+{
+ if (out->human_readable_units)
+ bch2_prt_human_readable_u64(out, v);
+ else
+ bch2_prt_printf(out, "%llu", v);
+}
+
+/**
+ * bch2_prt_units_s64() - Print out a s64 according to printbuf unit options
+ * @out: output printbuf
+ * @v: integer to print
+ *
+ * Units are either raw (default), or human reabable units (controlled via
+ * @buf->human_readable_units)
+ */
+void bch2_prt_units_s64(struct printbuf *out, s64 v)
+{
+ if (v < 0)
+ prt_char(out, '-');
+ bch2_prt_units_u64(out, abs(v));
+}
+
+void bch2_prt_string_option(struct printbuf *out,
+ const char * const list[],
+ size_t selected)
+{
+ size_t i;
+
+ for (i = 0; list[i]; i++)
+ bch2_prt_printf(out, i == selected ? "[%s] " : "%s ", list[i]);
+}
+
+void bch2_prt_bitflags(struct printbuf *out,
+ const char * const list[], u64 flags)
+{
+ unsigned bit, nr = 0;
+ bool first = true;
+
+ while (list[nr])
+ nr++;
+
+ while (flags && (bit = __ffs64(flags)) < nr) {
+ if (!first)
+ bch2_prt_printf(out, ",");
+ first = false;
+ bch2_prt_printf(out, "%s", list[bit]);
+ flags ^= BIT_ULL(bit);
+ }
+}
+
+void bch2_prt_bitflags_vector(struct printbuf *out,
+ const char * const list[],
+ unsigned long *v, unsigned nr)
+{
+ bool first = true;
+ unsigned i;
+
+ for (i = 0; i < nr; i++)
+ if (!list[i]) {
+ nr = i - 1;
+ break;
+ }
+
+ for_each_set_bit(i, v, nr) {
+ if (!first)
+ bch2_prt_printf(out, ",");
+ first = false;
+ bch2_prt_printf(out, "%s", list[i]);
+ }
+}