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-rw-r--r--src/bftw.c961
1 files changed, 451 insertions, 510 deletions
diff --git a/src/bftw.c b/src/bftw.c
index 553363e..2262591 100644
--- a/src/bftw.c
+++ b/src/bftw.c
@@ -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) {