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-rw-r--r--src/basic/rm-rf.c160
1 files changed, 113 insertions, 47 deletions
diff --git a/src/basic/rm-rf.c b/src/basic/rm-rf.c
index 29013077f2..77ffed9360 100644
--- a/src/basic/rm-rf.c
+++ b/src/basic/rm-rf.c
@@ -115,12 +115,13 @@ static int fstatat_harder(
return 0;
}
-static int rm_rf_children_inner(
+static int rm_rf_inner_child(
int fd,
const char *fname,
int is_dir,
RemoveFlags flags,
- const struct stat *root_dev) {
+ const struct stat *root_dev,
+ bool allow_recursion) {
struct stat st;
int r, q = 0;
@@ -140,9 +141,7 @@ static int rm_rf_children_inner(
}
if (is_dir) {
- _cleanup_close_ int subdir_fd = -1;
-
- /* if root_dev is set, remove subdirectories only if device is same */
+ /* If root_dev is set, remove subdirectories only if device is same */
if (root_dev && st.st_dev != root_dev->st_dev)
return 0;
@@ -154,7 +153,6 @@ static int rm_rf_children_inner(
return 0;
if ((flags & REMOVE_SUBVOLUME) && btrfs_might_be_subvol(&st)) {
-
/* This could be a subvolume, try to remove it */
r = btrfs_subvol_remove_fd(fd, fname, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
@@ -168,13 +166,16 @@ static int rm_rf_children_inner(
return 1;
}
- subdir_fd = openat(fd, fname, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+ if (!allow_recursion)
+ return -EISDIR;
+
+ int subdir_fd = openat(fd, fname, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
if (subdir_fd < 0)
return -errno;
/* We pass REMOVE_PHYSICAL here, to avoid doing the fstatfs() to check the file system type
* again for each directory */
- q = rm_rf_children(TAKE_FD(subdir_fd), flags | REMOVE_PHYSICAL, root_dev);
+ q = rm_rf_children(subdir_fd, flags | REMOVE_PHYSICAL, root_dev);
} else if (flags & REMOVE_ONLY_DIRECTORIES)
return 0;
@@ -187,63 +188,128 @@ static int rm_rf_children_inner(
return 1;
}
+typedef struct TodoEntry {
+ DIR *dir; /* A directory that we were operating on. */
+ char *dirname; /* The filename of that directory itself. */
+} TodoEntry;
+
+static void free_todo_entries(TodoEntry **todos) {
+ for (TodoEntry *x = *todos; x && x->dir; x++) {
+ closedir(x->dir);
+ free(x->dirname);
+ }
+
+ freep(todos);
+}
+
int rm_rf_children(
int fd,
RemoveFlags flags,
const struct stat *root_dev) {
- _cleanup_closedir_ DIR *d = NULL;
- struct dirent *de;
+ _cleanup_(free_todo_entries) TodoEntry *todos = NULL;
+ size_t n_todo = 0, n_todo_alloc = 0;
+ _cleanup_free_ char *dirname = NULL; /* Set when we are recursing and want to delete ourselves */
int ret = 0, r;
- assert(fd >= 0);
+ /* Return the first error we run into, but nevertheless try to go on.
+ * The passed fd is closed in all cases, including on failure. */
+
+ for (;;) { /* This loop corresponds to the directory nesting level. */
+ _cleanup_closedir_ DIR *d = NULL;
+
+ if (n_todo > 0) {
+ /* We know that we are in recursion here, because n_todo is set.
+ * We need to remove the inner directory we were operating on. */
+ assert(dirname);
+ r = unlinkat_harder(dirfd(todos[n_todo-1].dir), dirname, AT_REMOVEDIR, flags);
+ if (r < 0 && r != -ENOENT && ret == 0)
+ ret = r;
+ dirname = mfree(dirname);
+
+ /* And now let's back out one level up */
+ n_todo --;
+ d = TAKE_PTR(todos[n_todo].dir);
+ dirname = TAKE_PTR(todos[n_todo].dirname);
+
+ assert(d);
+ fd = dirfd(d); /* Retrieve the file descriptor from the DIR object */
+ assert(fd >= 0);
+ } else {
+ next_fd:
+ assert(fd >= 0);
+ d = fdopendir(fd);
+ if (!d) {
+ safe_close(fd);
+ return -errno;
+ }
+ fd = dirfd(d); /* We donated the fd to fdopendir(). Let's make sure we sure we have
+ * the right descriptor even if it were to internally invalidate the
+ * one we passed. */
+
+ if (!(flags & REMOVE_PHYSICAL)) {
+ struct statfs sfs;
+
+ if (fstatfs(fd, &sfs) < 0)
+ return -errno;
+
+ if (is_physical_fs(&sfs)) {
+ /* We refuse to clean physical file systems with this call, unless
+ * explicitly requested. This is extra paranoia just to be sure we
+ * never ever remove non-state data. */
+
+ _cleanup_free_ char *path = NULL;
+
+ (void) fd_get_path(fd, &path);
+ return log_error_errno(SYNTHETIC_ERRNO(EPERM),
+ "Attempted to remove disk file system under \"%s\", and we can't allow that.",
+ strna(path));
+ }
+ }
+ }
- /* This returns the first error we run into, but nevertheless tries to go on. This closes the passed
- * fd, in all cases, including on failure. */
+ struct dirent *de;
+ FOREACH_DIRENT_ALL(de, d, return -errno) {
+ int is_dir;
- d = fdopendir(fd);
- if (!d) {
- safe_close(fd);
- return -errno;
- }
+ if (dot_or_dot_dot(de->d_name))
+ continue;
- if (!(flags & REMOVE_PHYSICAL)) {
- struct statfs sfs;
+ is_dir = de->d_type == DT_UNKNOWN ? -1 : de->d_type == DT_DIR;
- if (fstatfs(dirfd(d), &sfs) < 0)
- return -errno;
+ r = rm_rf_inner_child(fd, de->d_name, is_dir, flags, root_dev, false);
+ if (r == -EISDIR) {
+ /* Push the current working state onto the todo list */
- if (is_physical_fs(&sfs)) {
- /* We refuse to clean physical file systems with this call, unless explicitly
- * requested. This is extra paranoia just to be sure we never ever remove non-state
- * data. */
+ if (!GREEDY_REALLOC0(todos, n_todo_alloc, n_todo + 2))
+ return log_oom();
- _cleanup_free_ char *path = NULL;
+ _cleanup_free_ char *newdirname = strdup(de->d_name);
+ if (!newdirname)
+ return log_oom();
- (void) fd_get_path(fd, &path);
- return log_error_errno(SYNTHETIC_ERRNO(EPERM),
- "Attempted to remove disk file system under \"%s\", and we can't allow that.",
- strna(path));
- }
- }
+ int newfd = openat(fd, de->d_name,
+ O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+ if (newfd >= 0) {
+ todos[n_todo++] = (TodoEntry) { TAKE_PTR(d), TAKE_PTR(dirname) };
+ fd = newfd;
+ dirname = TAKE_PTR(newdirname);
- FOREACH_DIRENT_ALL(de, d, return -errno) {
- int is_dir;
+ goto next_fd;
- if (dot_or_dot_dot(de->d_name))
- continue;
+ } else if (errno != -ENOENT && ret == 0)
+ ret = -errno;
- is_dir =
- de->d_type == DT_UNKNOWN ? -1 :
- de->d_type == DT_DIR;
+ } else if (r < 0 && r != -ENOENT && ret == 0)
+ ret = r;
+ }
- r = rm_rf_children_inner(dirfd(d), de->d_name, is_dir, flags, root_dev);
- if (r < 0 && r != -ENOENT && ret == 0)
- ret = r;
- }
+ if (FLAGS_SET(flags, REMOVE_SYNCFS) && syncfs(fd) < 0 && ret >= 0)
+ ret = -errno;
- if (FLAGS_SET(flags, REMOVE_SYNCFS) && syncfs(dirfd(d)) < 0 && ret >= 0)
- ret = -errno;
+ if (n_todo == 0)
+ break;
+ }
return ret;
}
@@ -336,5 +402,5 @@ int rm_rf_child(int fd, const char *name, RemoveFlags flags) {
if (FLAGS_SET(flags, REMOVE_ONLY_DIRECTORIES|REMOVE_SUBVOLUME))
return -EINVAL;
- return rm_rf_children_inner(fd, name, -1, flags, NULL);
+ return rm_rf_inner_child(fd, name, -1, flags, NULL, true);
}
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