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author | Kent Overstreet <kent.overstreet@linux.dev> | 2023-02-03 21:01:40 -0500 |
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committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-22 17:09:33 -0400 |
commit | 401ec4db630802729f10d53ad995083ced98caca (patch) | |
tree | 245f07e5928f1414b6da71f14c417829e763fdde /fs/bcachefs/printbuf.c | |
parent | 652018d66190412669a898c2dc3e75073eac8679 (diff) | |
download | linux-401ec4db630802729f10d53ad995083ced98caca.tar.gz linux-401ec4db630802729f10d53ad995083ced98caca.tar.bz2 linux-401ec4db630802729f10d53ad995083ced98caca.zip |
bcachefs: Printbuf rework
This converts bcachefs to the modern printbuf interface/implementation,
synced with the version to be submitted upstream.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/printbuf.c')
-rw-r--r-- | fs/bcachefs/printbuf.c | 415 |
1 files changed, 415 insertions, 0 deletions
diff --git a/fs/bcachefs/printbuf.c b/fs/bcachefs/printbuf.c new file mode 100644 index 000000000000..c41daa180682 --- /dev/null +++ b/fs/bcachefs/printbuf.c @@ -0,0 +1,415 @@ +// SPDX-License-Identifier: LGPL-2.1+ +/* Copyright (C) 2022 Kent Overstreet */ + +#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; +} + +/** + * printbuf_str - returns printbuf's buf as a C string, guaranteed to be null + * terminated + */ +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 + : ""; +} + +/** + * printbuf_exit - exit a printbuf, freeing memory it owns and poisoning it + * against accidental use. + */ +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; +} + +/* + * 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; +} + +/** + * 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; +} + +/** + * 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++; +} + +/** + * prt_tab - Advance printbuf to the next tabstop + * + * @buf: 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++; +} + +/** + * 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); +} + +/** + * prt_bytes_indented - Print an array of chars, handling embedded control characters + * + * @out: printbuf to output to + * @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); +} + +/** + * prt_human_readable_u64 - Print out a u64 in human readable units + * + * Units of 2^10 (default) or 10^3 are controlled via @buf->si_units + */ +void bch2_prt_human_readable_u64(struct printbuf *buf, u64 v) +{ + bch2_printbuf_make_room(buf, 10); + buf->pos += string_get_size(v, 1, !buf->si_units, + buf->buf + buf->pos, + printbuf_remaining_size(buf)); +} + +/** + * prt_human_readable_s64 - Print out a s64 in human readable units + * + * Units of 2^10 (default) or 10^3 are controlled via @buf->si_units + */ +void bch2_prt_human_readable_s64(struct printbuf *buf, s64 v) +{ + if (v < 0) + prt_char(buf, '-'); + bch2_prt_human_readable_u64(buf, abs(v)); +} + +/** + * prt_units_u64 - Print out a u64 according to printbuf unit options + * + * 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); +} + +/** + * prt_units_s64 - Print out a s64 according to printbuf unit options + * + * 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 = __ffs(flags)) < nr) { + if (!first) + bch2_prt_printf(out, ","); + first = false; + bch2_prt_printf(out, "%s", list[bit]); + flags ^= 1 << bit; + } +} |