diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/bftw.c | 961 |
1 files changed, 451 insertions, 510 deletions
@@ -34,6 +34,78 @@ #include <string.h> #include <sys/stat.h> +/** Caching bfs_stat(). */ +static const struct bfs_stat *bftw_stat_impl(struct BFTW *ftwbuf, struct bftw_stat *cache, enum bfs_stat_flags flags) { + if (!cache->buf) { + if (cache->error) { + errno = cache->error; + } else if (bfs_stat(ftwbuf->at_fd, ftwbuf->at_path, flags, &cache->storage) == 0) { + cache->buf = &cache->storage; + } else { + cache->error = errno; + } + } + + return cache->buf; +} + +const struct bfs_stat *bftw_stat(const struct BFTW *ftwbuf, enum bfs_stat_flags flags) { + struct BFTW *mutbuf = (struct BFTW *)ftwbuf; + const struct bfs_stat *ret; + + if (flags & BFS_STAT_NOFOLLOW) { + ret = bftw_stat_impl(mutbuf, &mutbuf->lstat_cache, BFS_STAT_NOFOLLOW); + if (ret && !S_ISLNK(ret->mode) && !mutbuf->stat_cache.buf) { + // Non-link, so share stat info + mutbuf->stat_cache.buf = ret; + } + } else { + ret = bftw_stat_impl(mutbuf, &mutbuf->stat_cache, BFS_STAT_FOLLOW); + if (!ret && (flags & BFS_STAT_TRYFOLLOW) && is_nonexistence_error(errno)) { + ret = bftw_stat_impl(mutbuf, &mutbuf->lstat_cache, BFS_STAT_NOFOLLOW); + } + } + + return ret; +} + +const struct bfs_stat *bftw_cached_stat(const struct BFTW *ftwbuf, enum bfs_stat_flags flags) { + if (flags & BFS_STAT_NOFOLLOW) { + 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)) { + return ftwbuf->lstat_cache.buf; + } else { + return NULL; + } +} + +enum bfs_type bftw_type(const struct BFTW *ftwbuf, enum bfs_stat_flags flags) { + if (flags & BFS_STAT_NOFOLLOW) { + if (ftwbuf->type == BFS_LNK || (ftwbuf->stat_flags & BFS_STAT_NOFOLLOW)) { + return ftwbuf->type; + } + } else if (flags & BFS_STAT_TRYFOLLOW) { + if (ftwbuf->type != BFS_LNK || (ftwbuf->stat_flags & BFS_STAT_TRYFOLLOW)) { + return ftwbuf->type; + } + } else { + if (ftwbuf->type != BFS_LNK) { + return ftwbuf->type; + } else if (ftwbuf->stat_flags & BFS_STAT_TRYFOLLOW) { + return BFS_ERROR; + } + } + + const struct bfs_stat *statbuf = bftw_stat(ftwbuf, flags); + if (statbuf) { + return bfs_mode_to_type(statbuf->mode); + } else { + return BFS_ERROR; + } +} + /** * A file. */ @@ -277,103 +349,7 @@ static struct bftw_file *bftw_file_new(struct bftw_cache *cache, struct bftw_fil return file; } -/** - * Open a bftw_file relative to another one. - * - * @param cache - * The cache to hold the file. - * @param file - * The file to open. - * @param base - * The base directory for the relative path (may be NULL). - * @param at_fd - * The base file descriptor, AT_FDCWD if base == NULL. - * @param at_path - * The relative path to the file. - * @return - * The opened file descriptor, or negative on error. - */ -static int bftw_file_openat(struct bftw_cache *cache, struct bftw_file *file, struct bftw_file *base, const char *at_path) { - bfs_assert(file->fd < 0); - - int at_fd = AT_FDCWD; - if (base) { - bftw_cache_pin(cache, base); - at_fd = base->fd; - } - - int flags = O_RDONLY | O_CLOEXEC | O_DIRECTORY; - int fd = openat(at_fd, at_path, flags); - - if (fd < 0 && errno == EMFILE) { - if (bftw_cache_pop(cache) == 0) { - fd = openat(at_fd, at_path, flags); - } - cache->capacity = 1; - } - - if (base) { - bftw_cache_unpin(cache, base); - } - - if (fd >= 0) { - file->fd = fd; - bftw_cache_add(cache, file); - } - - return file->fd; -} - -/** - * Open a bftw_file. - * - * @param cache - * The cache to hold the file. - * @param file - * The file to open. - * @param path - * The full path to the file. - * @return - * The opened file descriptor, or negative on error. - */ -static int bftw_file_open(struct bftw_cache *cache, struct bftw_file *file, const char *path) { - // Find the nearest open ancestor - struct bftw_file *base = file; - do { - base = base->parent; - } while (base && base->fd < 0); - - const char *at_path = path; - if (base) { - at_path += bftw_child_nameoff(base); - } - - int fd = bftw_file_openat(cache, file, base, at_path); - if (fd >= 0 || errno != ENAMETOOLONG) { - return fd; - } - - // Handle ENAMETOOLONG by manually traversing the path component-by-component - struct bftw_list parents; - SLIST_INIT(&parents); - - struct bftw_file *cur; - for (cur = file; cur != base; cur = cur->parent) { - SLIST_PREPEND(&parents, cur); - } - - while ((cur = SLIST_POP(&parents))) { - if (!cur->parent || cur->parent->fd >= 0) { - bftw_file_openat(cache, cur, cur->parent, cur->name); - } - } - - return file->fd; -} - -/** - * Associate an open directory with a bftw_file. - */ +/** Associate an open directory with a bftw_file. */ static void bftw_file_set_dir(struct bftw_cache *cache, struct bftw_file *file, struct bfs_dir *dir) { bfs_assert(!file->dir); file->dir = dir; @@ -384,38 +360,6 @@ static void bftw_file_set_dir(struct bftw_cache *cache, struct bftw_file *file, } } -/** - * Open a bftw_file as a directory. - * - * @param cache - * The cache to hold the file. - * @param file - * The directory to open. - * @param path - * The full path to the directory. - * @return - * The opened directory, or NULL on error. - */ -static struct bfs_dir *bftw_file_opendir(struct bftw_cache *cache, struct bftw_file *file, const char *path) { - int fd = bftw_file_open(cache, file, path); - if (fd < 0) { - return NULL; - } - - struct bfs_dir *dir = bftw_allocdir(cache); - if (!dir) { - return NULL; - } - - if (bfs_opendir(dir, fd, NULL) != 0) { - bftw_freedir(cache, dir); - return NULL; - } - - bftw_file_set_dir(cache, file, dir); - return dir; -} - /** Free a bftw_file. */ static void bftw_file_free(struct bftw_cache *cache, struct bftw_file *file) { bfs_assert(file->refcount == 0); @@ -480,9 +424,7 @@ struct bftw_state { struct BFTW ftwbuf; }; -/** - * Initialize the bftw() state. - */ +/** Initialize the bftw() state. */ static int bftw_state_init(struct bftw_state *state, const struct bftw_args *args) { state->callback = args->callback; state->ptr = args->ptr; @@ -542,344 +484,6 @@ static int bftw_state_init(struct bftw_state *state, const struct bftw_args *arg return 0; } -/** Cached bfs_stat(). */ -static const struct bfs_stat *bftw_stat_impl(struct BFTW *ftwbuf, struct bftw_stat *cache, enum bfs_stat_flags flags) { - if (!cache->buf) { - if (cache->error) { - errno = cache->error; - } else if (bfs_stat(ftwbuf->at_fd, ftwbuf->at_path, flags, &cache->storage) == 0) { - cache->buf = &cache->storage; - } else { - cache->error = errno; - } - } - - return cache->buf; -} - -const struct bfs_stat *bftw_stat(const struct BFTW *ftwbuf, enum bfs_stat_flags flags) { - struct BFTW *mutbuf = (struct BFTW *)ftwbuf; - const struct bfs_stat *ret; - - if (flags & BFS_STAT_NOFOLLOW) { - ret = bftw_stat_impl(mutbuf, &mutbuf->lstat_cache, BFS_STAT_NOFOLLOW); - if (ret && !S_ISLNK(ret->mode) && !mutbuf->stat_cache.buf) { - // Non-link, so share stat info - mutbuf->stat_cache.buf = ret; - } - } else { - ret = bftw_stat_impl(mutbuf, &mutbuf->stat_cache, BFS_STAT_FOLLOW); - if (!ret && (flags & BFS_STAT_TRYFOLLOW) && is_nonexistence_error(errno)) { - ret = bftw_stat_impl(mutbuf, &mutbuf->lstat_cache, BFS_STAT_NOFOLLOW); - } - } - - return ret; -} - -const struct bfs_stat *bftw_cached_stat(const struct BFTW *ftwbuf, enum bfs_stat_flags flags) { - if (flags & BFS_STAT_NOFOLLOW) { - 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)) { - return ftwbuf->lstat_cache.buf; - } else { - return NULL; - } -} - -enum bfs_type bftw_type(const struct BFTW *ftwbuf, enum bfs_stat_flags flags) { - if (flags & BFS_STAT_NOFOLLOW) { - if (ftwbuf->type == BFS_LNK || (ftwbuf->stat_flags & BFS_STAT_NOFOLLOW)) { - return ftwbuf->type; - } - } else if (flags & BFS_STAT_TRYFOLLOW) { - if (ftwbuf->type != BFS_LNK || (ftwbuf->stat_flags & BFS_STAT_TRYFOLLOW)) { - return ftwbuf->type; - } - } else { - if (ftwbuf->type != BFS_LNK) { - return ftwbuf->type; - } else if (ftwbuf->stat_flags & BFS_STAT_TRYFOLLOW) { - return BFS_ERROR; - } - } - - const struct bfs_stat *statbuf = bftw_stat(ftwbuf, flags); - if (statbuf) { - return bfs_mode_to_type(statbuf->mode); - } else { - return BFS_ERROR; - } -} - -/** - * Build the path to the current file. - */ -static int bftw_build_path(struct bftw_state *state, const char *name) { - const struct bftw_file *file = state->file; - - size_t pathlen = file ? file->nameoff + file->namelen : 0; - if (dstresize(&state->path, pathlen) != 0) { - state->error = errno; - return -1; - } - - // Try to find a common ancestor with the existing path - const struct bftw_file *ancestor = state->previous; - while (ancestor && ancestor->depth > file->depth) { - ancestor = ancestor->parent; - } - - // Build the path backwards - while (file && file != ancestor) { - if (file->nameoff > 0) { - state->path[file->nameoff - 1] = '/'; - } - memcpy(state->path + file->nameoff, file->name, file->namelen); - - if (ancestor && ancestor->depth == file->depth) { - ancestor = ancestor->parent; - } - file = file->parent; - } - - state->previous = state->file; - - if (name) { - if (pathlen > 0 && state->path[pathlen - 1] != '/') { - if (dstrapp(&state->path, '/') != 0) { - state->error = errno; - return -1; - } - } - if (dstrcat(&state->path, name) != 0) { - state->error = errno; - return -1; - } - } - - return 0; -} - -/** Check if a stat() call is needed for this visit. */ -static bool bftw_need_stat(const struct bftw_state *state) { - if (state->flags & BFTW_STAT) { - return true; - } - - const struct BFTW *ftwbuf = &state->ftwbuf; - if (ftwbuf->type == BFS_UNKNOWN) { - return true; - } - - if (ftwbuf->type == BFS_LNK && !(ftwbuf->stat_flags & BFS_STAT_NOFOLLOW)) { - return true; - } - - if (ftwbuf->type == BFS_DIR) { - if (state->flags & (BFTW_DETECT_CYCLES | BFTW_SKIP_MOUNTS | BFTW_PRUNE_MOUNTS)) { - return true; - } -#if __linux__ - } else if (state->mtab) { - // Linux fills in d_type from the underlying inode, even when - // the directory entry is a bind mount point. In that case, we - // need to stat() to get the correct type. We don't need to - // check for directories because they can only be mounted over - // by other directories. - if (bfs_might_be_mount(state->mtab, ftwbuf->path)) { - return true; - } -#endif - } - - return false; -} - -/** Initialize bftw_stat cache. */ -static void bftw_stat_init(struct bftw_stat *cache) { - cache->buf = NULL; - cache->error = 0; -} - -/** - * Open a file if necessary. - * - * @param file - * The file to open. - * @param path - * The path to that file or one of its descendants. - * @return - * The opened file descriptor, or -1 on error. - */ -static int bftw_ensure_open(struct bftw_cache *cache, struct bftw_file *file, const char *path) { - int ret = file->fd; - - if (ret < 0) { - char *copy = strndup(path, file->nameoff + file->namelen); - if (!copy) { - return -1; - } - - ret = bftw_file_open(cache, file, copy); - free(copy); - } - - return ret; -} - -/** - * Initialize the buffers with data about the current path. - */ -static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) { - struct bftw_file *file = state->file; - const struct bfs_dirent *de = state->de; - - struct BFTW *ftwbuf = &state->ftwbuf; - ftwbuf->path = state->path; - ftwbuf->root = file ? file->root->name : ftwbuf->path; - ftwbuf->depth = 0; - ftwbuf->visit = visit; - ftwbuf->type = BFS_UNKNOWN; - ftwbuf->error = state->direrror; - ftwbuf->at_fd = AT_FDCWD; - ftwbuf->at_path = ftwbuf->path; - ftwbuf->stat_flags = BFS_STAT_NOFOLLOW; - bftw_stat_init(&ftwbuf->lstat_cache); - bftw_stat_init(&ftwbuf->stat_cache); - - struct bftw_file *parent = NULL; - if (de) { - parent = file; - ftwbuf->depth = file->depth + 1; - ftwbuf->type = de->type; - ftwbuf->nameoff = bftw_child_nameoff(file); - } else if (file) { - parent = file->parent; - ftwbuf->depth = file->depth; - ftwbuf->type = file->type; - ftwbuf->nameoff = file->nameoff; - } - - if (parent) { - // Try to ensure the immediate parent is open, to avoid ENAMETOOLONG - if (bftw_ensure_open(&state->cache, parent, state->path) >= 0) { - ftwbuf->at_fd = parent->fd; - ftwbuf->at_path += ftwbuf->nameoff; - } else { - ftwbuf->error = errno; - } - } - - if (ftwbuf->depth == 0) { - // Compute the name offset for root paths like "foo/bar" - ftwbuf->nameoff = xbaseoff(ftwbuf->path); - } - - if (ftwbuf->error != 0) { - ftwbuf->type = BFS_ERROR; - return; - } - - int follow_flags = BFTW_FOLLOW_ALL; - if (ftwbuf->depth == 0) { - follow_flags |= BFTW_FOLLOW_ROOTS; - } - bool follow = state->flags & follow_flags; - if (follow) { - ftwbuf->stat_flags = BFS_STAT_TRYFOLLOW; - } - - const struct bfs_stat *statbuf = NULL; - if (bftw_need_stat(state)) { - statbuf = bftw_stat(ftwbuf, ftwbuf->stat_flags); - if (statbuf) { - ftwbuf->type = bfs_mode_to_type(statbuf->mode); - } else { - ftwbuf->type = BFS_ERROR; - ftwbuf->error = errno; - return; - } - } - - if (ftwbuf->type == BFS_DIR && (state->flags & BFTW_DETECT_CYCLES)) { - for (const struct bftw_file *ancestor = parent; ancestor; ancestor = ancestor->parent) { - if (ancestor->dev == statbuf->dev && ancestor->ino == statbuf->ino) { - ftwbuf->type = BFS_ERROR; - ftwbuf->error = ELOOP; - return; - } - } - } -} - -/** Check if the current file is a mount point. */ -static bool bftw_is_mount(struct bftw_state *state, const char *name) { - const struct bftw_file *file = state->file; - if (!file) { - return false; - } - - const struct bftw_file *parent = name ? file : file->parent; - if (!parent) { - return false; - } - - const struct BFTW *ftwbuf = &state->ftwbuf; - const struct bfs_stat *statbuf = bftw_stat(ftwbuf, ftwbuf->stat_flags); - return statbuf && statbuf->dev != parent->dev; -} - -/** - * Invoke the callback. - */ -static enum bftw_action bftw_call_back(struct bftw_state *state, const char *name, enum bftw_visit visit) { - if (visit == BFTW_POST && !(state->flags & BFTW_POST_ORDER)) { - return BFTW_PRUNE; - } - - if (bftw_build_path(state, name) != 0) { - return BFTW_STOP; - } - - const struct BFTW *ftwbuf = &state->ftwbuf; - bftw_init_ftwbuf(state, visit); - - // Never give the callback BFS_ERROR unless BFTW_RECOVER is specified - if (ftwbuf->type == BFS_ERROR && !(state->flags & BFTW_RECOVER)) { - state->error = ftwbuf->error; - return BFTW_STOP; - } - - if ((state->flags & BFTW_SKIP_MOUNTS) && bftw_is_mount(state, name)) { - return BFTW_PRUNE; - } - - enum bftw_action ret = state->callback(ftwbuf, state->ptr); - switch (ret) { - case BFTW_CONTINUE: - if (visit != BFTW_PRE) { - return BFTW_PRUNE; - } - if (ftwbuf->type != BFS_DIR) { - return BFTW_PRUNE; - } - if ((state->flags & BFTW_PRUNE_MOUNTS) && bftw_is_mount(state, name)) { - return BFTW_PRUNE; - } - fallthru; - case BFTW_PRUNE: - case BFTW_STOP: - return ret; - - default: - state->error = EINVAL; - return BFTW_STOP; - } -} - /** Pop a response from the I/O queue. */ static int bftw_ioq_pop(struct bftw_state *state, bool block) { struct ioq *ioq = state->ioq; @@ -962,7 +566,7 @@ static int bftw_cache_reserve(struct bftw_state *state) { return 0; } - while (bftw_ioq_pop(state, false) >= 0) { + while (bftw_ioq_pop(state, true) >= 0) { if (cache->capacity > 0) { return 0; } @@ -971,6 +575,76 @@ static int bftw_cache_reserve(struct bftw_state *state) { return bftw_cache_pop(cache); } +/** Open a bftw_file relative to another one. */ +static int bftw_file_openat(struct bftw_state *state, struct bftw_file *file, struct bftw_file *base, const char *at_path) { + bfs_assert(file->fd < 0); + + struct bftw_cache *cache = &state->cache; + + int at_fd = AT_FDCWD; + if (base) { + bftw_cache_pin(cache, base); + at_fd = base->fd; + } + + int flags = O_RDONLY | O_CLOEXEC | O_DIRECTORY; + int fd = openat(at_fd, at_path, flags); + + if (fd < 0 && errno == EMFILE) { + if (bftw_cache_pop(cache) == 0) { + fd = openat(at_fd, at_path, flags); + } + cache->capacity = 1; + } + + if (base) { + bftw_cache_unpin(cache, base); + } + + if (fd >= 0) { + file->fd = fd; + bftw_cache_add(cache, file); + } + + return file->fd; +} + +/** Open a bftw_file. */ +static int bftw_file_open(struct bftw_state *state, struct bftw_file *file, const char *path) { + // Find the nearest open ancestor + struct bftw_file *base = file; + do { + base = base->parent; + } while (base && base->fd < 0); + + const char *at_path = path; + if (base) { + at_path += bftw_child_nameoff(base); + } + + int fd = bftw_file_openat(state, file, base, at_path); + if (fd >= 0 || errno != ENAMETOOLONG) { + return fd; + } + + // Handle ENAMETOOLONG by manually traversing the path component-by-component + struct bftw_list parents; + SLIST_INIT(&parents); + + struct bftw_file *cur; + for (cur = file; cur != base; cur = cur->parent) { + SLIST_PREPEND(&parents, cur); + } + + while ((cur = SLIST_POP(&parents))) { + if (!cur->parent || cur->parent->fd >= 0) { + bftw_file_openat(state, cur, cur->parent, cur->name); + } + } + + return file->fd; +} + /** Push a directory onto the queue. */ static void bftw_push_dir(struct bftw_state *state, struct bftw_file *file) { bfs_assert(file->type == BFS_DIR); @@ -1165,9 +839,76 @@ static bool bftw_pop_file(struct bftw_state *state) { return (state->file = SLIST_POP(&state->files)); } -/** - * Open the current directory. - */ +/** Build the path to the current file. */ +static int bftw_build_path(struct bftw_state *state, const char *name) { + const struct bftw_file *file = state->file; + + size_t pathlen = file ? file->nameoff + file->namelen : 0; + if (dstresize(&state->path, pathlen) != 0) { + state->error = errno; + return -1; + } + + // Try to find a common ancestor with the existing path + const struct bftw_file *ancestor = state->previous; + while (ancestor && ancestor->depth > file->depth) { + ancestor = ancestor->parent; + } + + // Build the path backwards + while (file && file != ancestor) { + if (file->nameoff > 0) { + state->path[file->nameoff - 1] = '/'; + } + memcpy(state->path + file->nameoff, file->name, file->namelen); + + if (ancestor && ancestor->depth == file->depth) { + ancestor = ancestor->parent; + } + file = file->parent; + } + + state->previous = state->file; + + if (name) { + if (pathlen > 0 && state->path[pathlen - 1] != '/') { + if (dstrapp(&state->path, '/') != 0) { + state->error = errno; + return -1; + } + } + if (dstrcat(&state->path, name) != 0) { + state->error = errno; + return -1; + } + } + + return 0; +} + +/** Open a bftw_file as a directory. */ +static struct bfs_dir *bftw_file_opendir(struct bftw_state *state, struct bftw_file *file, const char *path) { + int fd = bftw_file_open(state, file, path); + if (fd < 0) { + return NULL; + } + + struct bftw_cache *cache = &state->cache; + struct bfs_dir *dir = bftw_allocdir(cache); + if (!dir) { + return NULL; + } + + if (bfs_opendir(dir, fd, NULL) != 0) { + bftw_freedir(cache, dir); + return NULL; + } + + bftw_file_set_dir(cache, file, dir); + return dir; +} + +/** Open the current directory. */ static int bftw_opendir(struct bftw_state *state) { bfs_assert(!state->dir); bfs_assert(!state->de); @@ -1181,7 +922,7 @@ static int bftw_opendir(struct bftw_state *state) { if (bftw_build_path(state, NULL) != 0) { return -1; } - state->dir = bftw_file_opendir(&state->cache, file, state->path); + state->dir = bftw_file_opendir(state, file, state->path); } if (state->dir) { @@ -1193,9 +934,7 @@ static int bftw_opendir(struct bftw_state *state) { return 0; } -/** - * Read an entry from the current directory. - */ +/** Read an entry from the current directory. */ static int bftw_readdir(struct bftw_state *state) { if (!state->dir) { return -1; @@ -1214,6 +953,210 @@ static int bftw_readdir(struct bftw_state *state) { return ret; } +/** Check if a stat() call is needed for this visit. */ +static bool bftw_need_stat(const struct bftw_state *state) { + if (state->flags & BFTW_STAT) { + return true; + } + + const struct BFTW *ftwbuf = &state->ftwbuf; + if (ftwbuf->type == BFS_UNKNOWN) { + return true; + } + + if (ftwbuf->type == BFS_LNK && !(ftwbuf->stat_flags & BFS_STAT_NOFOLLOW)) { + return true; + } + + if (ftwbuf->type == BFS_DIR) { + if (state->flags & (BFTW_DETECT_CYCLES | BFTW_SKIP_MOUNTS | BFTW_PRUNE_MOUNTS)) { + return true; + } +#if __linux__ + } else if (state->mtab) { + // Linux fills in d_type from the underlying inode, even when + // the directory entry is a bind mount point. In that case, we + // need to stat() to get the correct type. We don't need to + // check for directories because they can only be mounted over + // by other directories. + if (bfs_might_be_mount(state->mtab, ftwbuf->path)) { + return true; + } +#endif + } + + return false; +} + +/** Initialize bftw_stat cache. */ +static void bftw_stat_init(struct bftw_stat *cache) { + cache->buf = NULL; + cache->error = 0; +} + +/** Open a file if necessary. */ +static int bftw_ensure_open(struct bftw_state *state, struct bftw_file *file, const char *path) { + int ret = file->fd; + + if (ret < 0) { + char *copy = strndup(path, file->nameoff + file->namelen); + if (!copy) { + return -1; + } + + ret = bftw_file_open(state, file, copy); + free(copy); + } + + return ret; +} + +/** Initialize the buffers with data about the current path. */ +static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) { + struct bftw_file *file = state->file; + const struct bfs_dirent *de = state->de; + + struct BFTW *ftwbuf = &state->ftwbuf; + ftwbuf->path = state->path; + ftwbuf->root = file ? file->root->name : ftwbuf->path; + ftwbuf->depth = 0; + ftwbuf->visit = visit; + ftwbuf->type = BFS_UNKNOWN; + ftwbuf->error = state->direrror; + ftwbuf->at_fd = AT_FDCWD; + ftwbuf->at_path = ftwbuf->path; + ftwbuf->stat_flags = BFS_STAT_NOFOLLOW; + bftw_stat_init(&ftwbuf->lstat_cache); + bftw_stat_init(&ftwbuf->stat_cache); + + struct bftw_file *parent = NULL; + if (de) { + parent = file; + ftwbuf->depth = file->depth + 1; + ftwbuf->type = de->type; + ftwbuf->nameoff = bftw_child_nameoff(file); + } else if (file) { + parent = file->parent; + ftwbuf->depth = file->depth; + ftwbuf->type = file->type; + ftwbuf->nameoff = file->nameoff; + } + + if (parent) { + // Try to ensure the immediate parent is open, to avoid ENAMETOOLONG + if (bftw_ensure_open(state, parent, state->path) >= 0) { + ftwbuf->at_fd = parent->fd; + ftwbuf->at_path += ftwbuf->nameoff; + } else { + ftwbuf->error = errno; + } + } + + if (ftwbuf->depth == 0) { + // Compute the name offset for root paths like "foo/bar" + ftwbuf->nameoff = xbaseoff(ftwbuf->path); + } + + if (ftwbuf->error != 0) { + ftwbuf->type = BFS_ERROR; + return; + } + + int follow_flags = BFTW_FOLLOW_ALL; + if (ftwbuf->depth == 0) { + follow_flags |= BFTW_FOLLOW_ROOTS; + } + bool follow = state->flags & follow_flags; + if (follow) { + ftwbuf->stat_flags = BFS_STAT_TRYFOLLOW; + } + + const struct bfs_stat *statbuf = NULL; + if (bftw_need_stat(state)) { + statbuf = bftw_stat(ftwbuf, ftwbuf->stat_flags); + if (statbuf) { + ftwbuf->type = bfs_mode_to_type(statbuf->mode); + } else { + ftwbuf->type = BFS_ERROR; + ftwbuf->error = errno; + return; + } + } + + if (ftwbuf->type == BFS_DIR && (state->flags & BFTW_DETECT_CYCLES)) { + for (const struct bftw_file *ancestor = parent; ancestor; ancestor = ancestor->parent) { + if (ancestor->dev == statbuf->dev && ancestor->ino == statbuf->ino) { + ftwbuf->type = BFS_ERROR; + ftwbuf->error = ELOOP; + return; + } + } + } +} + +/** Check if the current file is a mount point. */ +static bool bftw_is_mount(struct bftw_state *state, const char *name) { + const struct bftw_file *file = state->file; + if (!file) { + return false; + } + + const struct bftw_file *parent = name ? file : file->parent; + if (!parent) { + return false; + } + + const struct BFTW *ftwbuf = &state->ftwbuf; + const struct bfs_stat *statbuf = bftw_stat(ftwbuf, ftwbuf->stat_flags); + return statbuf && statbuf->dev != parent->dev; +} + +/** Invoke the callback. */ +static enum bftw_action bftw_call_back(struct bftw_state *state, const char *name, enum bftw_visit visit) { + if (visit == BFTW_POST && !(state->flags & BFTW_POST_ORDER)) { + return BFTW_PRUNE; + } + + if (bftw_build_path(state, name) != 0) { + return BFTW_STOP; + } + + const struct BFTW *ftwbuf = &state->ftwbuf; + bftw_init_ftwbuf(state, visit); + + // Never give the callback BFS_ERROR unless BFTW_RECOVER is specified + if (ftwbuf->type == BFS_ERROR && !(state->flags & BFTW_RECOVER)) { + state->error = ftwbuf->error; + return BFTW_STOP; + } + + if ((state->flags & BFTW_SKIP_MOUNTS) && bftw_is_mount(state, name)) { + return BFTW_PRUNE; + } + + enum bftw_action ret = state->callback(ftwbuf, state->ptr); + switch (ret) { + case BFTW_CONTINUE: + if (visit != BFTW_PRE) { + return BFTW_PRUNE; + } + if (ftwbuf->type != BFS_DIR) { + return BFTW_PRUNE; + } + if ((state->flags & BFTW_PRUNE_MOUNTS) && bftw_is_mount(state, name)) { + return BFTW_PRUNE; + } + fallthru; + case BFTW_PRUNE: + case BFTW_STOP: + return ret; + + default: + state->error = EINVAL; + return BFTW_STOP; + } +} + /** * Flags controlling which files get visited when done with a directory. */ @@ -1230,9 +1173,7 @@ enum bftw_gc_flags { BFTW_VISIT_ALL = BFTW_VISIT_ERROR | BFTW_VISIT_FILE | BFTW_VISIT_PARENTS, }; -/** - * Garbage collect the current file and its parents. - */ +/** Garbage collect the current file and its parents. */ static int bftw_gc(struct bftw_state *state, enum bftw_gc_flags flags) { int ret = 0; @@ -1286,35 +1227,6 @@ static int bftw_gc(struct bftw_state *state, enum bftw_gc_flags flags) { return ret; } -/** - * Dispose of the bftw() state. - * - * @return - * The bftw() return value. - */ -static int bftw_state_destroy(struct bftw_state *state) { - dstrfree(state->path); - - struct ioq *ioq = state->ioq; - if (ioq) { - ioq_cancel(ioq); - while (bftw_ioq_pop(state, true) >= 0); - state->ioq = NULL; - } - - SLIST_EXTEND(&state->files, &state->batch); - do { - bftw_gc(state, BFTW_VISIT_NONE); - } while (bftw_pop_dir(state) || bftw_pop_file(state)); - - ioq_destroy(ioq); - - bftw_cache_destroy(&state->cache); - - errno = state->error; - return state->error ? -1 : 0; -} - /** Sort a bftw_list by filename. */ static void bftw_list_sort(struct bftw_list *list) { if (!list->head || !list->head->next) { @@ -1437,6 +1349,35 @@ static int bftw_visit(struct bftw_state *state, const char *name) { } /** + * Dispose of the bftw() state. + * + * @return + * The bftw() return value. + */ +static int bftw_state_destroy(struct bftw_state *state) { + dstrfree(state->path); + + struct ioq *ioq = state->ioq; + if (ioq) { + ioq_cancel(ioq); + while (bftw_ioq_pop(state, true) >= 0); + state->ioq = NULL; + } + + SLIST_EXTEND(&state->files, &state->batch); + do { + bftw_gc(state, BFTW_VISIT_NONE); + } while (bftw_pop_dir(state) || bftw_pop_file(state)); + + ioq_destroy(ioq); + + bftw_cache_destroy(&state->cache); + + errno = state->error; + return state->error ? -1 : 0; +} + +/** * bftw() implementation for simple breadth-/depth-first search. */ static int bftw_impl(const struct bftw_args *args) { |