From e9588c49d5539ded993f720fc6855d6fa878c997 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Sat, 13 Jan 2024 12:42:42 -0500 Subject: bfstd: New {error,errno}_is_like() functions We used to have is_nonexistence_error() to consistently treat ENOENT and ENOTDIR the same. Recently, we started considering EFAULT the same as ENAMETOOLONG on DragonFly BSD to work around a kernel bug. Unify both of these behind a more generic interface. --- src/bfstd.c | 23 +++++++++++++++++++++-- src/bfstd.h | 18 ++++++++++++++++-- src/bftw.c | 18 +++--------------- src/eval.c | 2 +- src/stat.c | 2 +- tests/xtouch.c | 17 +++-------------- 6 files changed, 45 insertions(+), 35 deletions(-) diff --git a/src/bfstd.c b/src/bfstd.c index c0e61cb..15e8667 100644 --- a/src/bfstd.c +++ b/src/bfstd.c @@ -36,8 +36,27 @@ # include #endif -bool is_nonexistence_error(int error) { - return error == ENOENT || errno == ENOTDIR; +bool error_is_like(int error, int category) { + if (error == category) { + return true; + } + + switch (category) { + case ENOENT: + return error == ENOTDIR; + +#if __DragonFly__ + // https://twitter.com/tavianator/status/1742991411203485713 + case ENAMETOOLONG: + return error == EFAULT; +#endif + } + + return false; +} + +bool errno_is_like(int category) { + return error_is_like(errno, category); } char *xdirname(const char *path) { diff --git a/src/bfstd.h b/src/bfstd.h index 0fcb892..8953b9b 100644 --- a/src/bfstd.h +++ b/src/bfstd.h @@ -45,9 +45,23 @@ // #include /** - * Return whether an error code is due to a path not existing. + * Check if an error code is "like" another one. For example, ENOTDIR is + * like ENOENT because they can both be triggered by non-existent paths. + * + * @param error + * The error code to check. + * @param category + * The category to test for. Known categories include ENOENT and + * ENAMETOOLONG. + * @return + * Whether the error belongs to the given category. + */ +bool error_is_like(int error, int category); + +/** + * Equivalent to error_is_like(errno, category). */ -bool is_nonexistence_error(int error); +bool errno_is_like(int category); #include diff --git a/src/bftw.c b/src/bftw.c index 355cb54..49f07df 100644 --- a/src/bftw.c +++ b/src/bftw.c @@ -68,7 +68,7 @@ const struct bfs_stat *bftw_stat(const struct BFTW *ftwbuf, enum bfs_stat_flags } } else { ret = bftw_stat_impl(mutbuf, &mutbuf->stat_cache, BFS_STAT_FOLLOW); - if (!ret && (flags & BFS_STAT_TRYFOLLOW) && is_nonexistence_error(errno)) { + if (!ret && (flags & BFS_STAT_TRYFOLLOW) && errno_is_like(ENOENT)) { ret = bftw_stat_impl(mutbuf, &mutbuf->lstat_cache, BFS_STAT_NOFOLLOW); } } @@ -81,7 +81,7 @@ const struct bfs_stat *bftw_cached_stat(const struct BFTW *ftwbuf, enum bfs_stat return ftwbuf->lstat_cache.buf; } else if (ftwbuf->stat_cache.buf) { return ftwbuf->stat_cache.buf; - } else if ((flags & BFS_STAT_TRYFOLLOW) && is_nonexistence_error(ftwbuf->stat_cache.error)) { + } else if ((flags & BFS_STAT_TRYFOLLOW) && error_is_like(ftwbuf->stat_cache.error, ENOENT)) { return ftwbuf->lstat_cache.buf; } else { return NULL; @@ -739,22 +739,10 @@ static int bftw_file_open(struct bftw_state *state, struct bftw_file *file, cons } int fd = bftw_file_openat(state, file, base, at_path); - if (fd >= 0) { + if (fd >= 0 || !errno_is_like(ENAMETOOLONG)) { return fd; } - switch (errno) { - case ENAMETOOLONG: -#if __DragonFly__ - // https://twitter.com/tavianator/status/1742991411203485713 - case EFAULT: -#endif - break; - - default: - return -1; - } - // Handle ENAMETOOLONG by manually traversing the path component-by-component struct bftw_list parents; SLIST_INIT(&parents); diff --git a/src/eval.c b/src/eval.c index 130b366..1a814b3 100644 --- a/src/eval.c +++ b/src/eval.c @@ -80,7 +80,7 @@ static void eval_error(struct bfs_eval *state, const char *format, ...) { */ static bool eval_should_ignore(const struct bfs_eval *state, int error) { return state->ctx->ignore_races - && is_nonexistence_error(error) + && error_is_like(error, ENOENT) && state->ftwbuf->depth > 0; } diff --git a/src/stat.c b/src/stat.c index d7387c6..91aa092 100644 --- a/src/stat.c +++ b/src/stat.c @@ -260,7 +260,7 @@ static int bfs_stat_tryfollow(int at_fd, const char *at_path, int at_flags, int if (ret != 0 && (bfs_flags & (BFS_STAT_NOFOLLOW | BFS_STAT_TRYFOLLOW)) == BFS_STAT_TRYFOLLOW - && is_nonexistence_error(errno)) + && errno_is_like(ENOENT)) { at_flags |= AT_SYMLINK_NOFOLLOW; ret = bfs_stat_explicit(at_fd, at_path, at_flags, x_flags, buf); diff --git a/tests/xtouch.c b/tests/xtouch.c index ed8bbee..6099128 100644 --- a/tests/xtouch.c +++ b/tests/xtouch.c @@ -68,22 +68,11 @@ static int open_parent(const struct args *args, const char **path) { goto done; } - switch (errno) { - case ENAMETOOLONG: -#if __DragonFly__ - // https://twitter.com/tavianator/status/1742991411203485713 - case EFAULT: -#endif - break; - - case ENOENT: - if (args->flags & CREATE_PARENTS) { - break; - } else { + if (errno == ENOENT) { + if (!(args->flags & CREATE_PARENTS)) { goto err; } - - default: + } else if (!errno_is_like(ENAMETOOLONG)) { goto err; } -- cgit v1.2.3