diff options
Diffstat (limited to 'util/nvmutil/lib/io.c')
| -rw-r--r-- | util/nvmutil/lib/io.c | 67 |
1 files changed, 32 insertions, 35 deletions
diff --git a/util/nvmutil/lib/io.c b/util/nvmutil/lib/io.c index 06fd038f..5769dd05 100644 --- a/util/nvmutil/lib/io.c +++ b/util/nvmutil/lib/io.c @@ -1,5 +1,4 @@ /* SPDX-License-Identifier: MIT - * * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> * * I/O functions specific to nvmutil. @@ -44,12 +43,11 @@ open_gbe_file(void) if (_flags == -1) err(errno, "%s: fcntl(F_GETFL)", f->fname); - /* - * O_APPEND must not be used, because this - * allows POSIX write() to ignore the - * current write offset and write at EOF, - * which would therefore break pread/pwrite + /* O_APPEND allows POSIX write() to ignore + * the current write offset and write at EOF, + * which would break positional read/write */ + if (_flags & O_APPEND) err(EIO, "%s: O_APPEND flag", f->fname); @@ -223,10 +221,10 @@ write_to_gbe_bin(void) write_gbe_file(); - /* - * We may otherwise read from + /* We may otherwise read from * cache, so we must sync. */ + if (fsync_on_eintr(f->tmp_fd) == -1) err(errno, "%s: fsync (pre-verification)", f->tname); @@ -239,11 +237,6 @@ write_to_gbe_bin(void) if (f->io_err_gbe) err(EIO, "%s: bad write", f->fname); - /* - * success! - * now just rename the tmpfile - */ - saved_errno = errno; if (close_on_eintr(f->tmp_fd) == -1) { @@ -258,6 +251,11 @@ write_to_gbe_bin(void) errno = saved_errno; + /* tmpfile written, now we + * rename it back to the main file + * (we do atomic writes) + */ + f->tmp_fd = -1; f->gbe_fd = -1; @@ -275,6 +273,7 @@ write_to_gbe_bin(void) /* removed by rename */ + if (f->tname != NULL) free(f->tname); @@ -338,17 +337,17 @@ check_written_part(unsigned long p) f->rw_check_partial_read[p]) return; - /* - * We only load one part on-file, into memory but + /* We only load one part on-file, into memory but * always at offset zero, for post-write checks. - * That's why we hardcode good_checksum(0). + * That's why we hardcode good_checksum(0) */ + buf_restore = f->buf; - /* - * good_checksum works on f->buf + /* good_checksum works on f->buf * so let's change f->buf for now */ + f->buf = f->pad; if (good_checksum(0)) @@ -427,7 +426,8 @@ gbe_mv(void) char *dest_tmp; int dest_fd; - /* will be set 0 if it doesn't */ + /* will be set 0 if it doesn't + */ tmp_gbe_bin_exists = 1; dest_tmp = NULL; @@ -438,8 +438,8 @@ gbe_mv(void) rval = rename(f->tname, f->fname); if (rval > -1) { - /* - * same filesystem + + /* rename on same filesystem */ tmp_gbe_bin_exists = 0; @@ -455,19 +455,22 @@ gbe_mv(void) if (errno != EXDEV) goto ret_gbe_mv; - /* cross-filesystem rename */ + /* + * OR, cross-filesystem rename: + */ if ((rval = f->tmp_fd = open(f->tname, O_RDONLY | O_BINARY)) == -1) goto ret_gbe_mv; - /* create replacement temp in target directory */ + /* create replacement temp in target directory + */ dest_tmp = new_tmpfile(&dest_fd, 1, f->fname); if (dest_tmp == NULL) goto ret_gbe_mv; - /* copy data */ - + /* copy data + */ rval = rw_file_exact(f->tmp_fd, f->bufcmp, f->gbe_file_size, 0, IO_PREAD, NO_LOOP_EAGAIN, LOOP_EINTR, @@ -520,8 +523,7 @@ ret_gbe_mv: f->tmp_fd = -1; } - /* - * before this function is called, + /* before this function is called, * tmp_fd may have been moved */ if (tmp_gbe_bin_exists) { @@ -532,8 +534,7 @@ ret_gbe_mv: } if (rval < 0) { - /* - * if nothing set errno, + /* if nothing set errno, * we assume EIO, or we * use what was set */ @@ -546,8 +547,7 @@ ret_gbe_mv: return rval; } -/* - * This one is similar to gbe_file_offset, +/* This one is similar to gbe_file_offset, * but used to check Gbe bounds in memory, * and it is *also* used during file I/O. */ @@ -566,12 +566,9 @@ gbe_mem_offset(unsigned long p, const char *f_op) (f->buf + (unsigned long)gbe_off); } -/* - * I/O operations filtered here. These operations must +/* I/O operations filtered here. These operations must * only write from the 0th position or the half position * within the GbE file, and write 4KB of data. - * - * This check is called, to ensure just that. */ off_t gbe_file_offset(unsigned long p, const char *f_op) |