Quoth Jani Nikula on May 08 at 12:08 am: > On May 7, 2012 9:10 PM, "Austin Clements" <[1]amdragon@mit.edu> wrote: > > > > This moves our logic to get a file's type into one function. This has > > several benefits: we can support OSes and file systems that do not > > provide dirent.d_type or always return DT_UNKNOWN, complex > > symlink-handling logic has been replaced by a simple stat fall-through > > in one place, and the error message for un-stat-able file is more > > accurate (previously, the error always mentioned directories, even > > though a broken symlink is not a directory). > > Please find some quick drive-by-review below. Thanks for the review! New version on its way... > J. > > > --- > > notmuch-new.c | 99 > ++++++++++++++++++++++++++++++++++----------------------- > > test/new | 2 +- > > 2 files changed, 60 insertions(+), 41 deletions(-) > > > > diff --git a/notmuch-new.c b/notmuch-new.c > > index cb720cc..cf2580e 100644 > > --- a/notmuch-new.c > > +++ b/notmuch-new.c > > @@ -154,6 +154,44 @@ dirent_sort_strcmp_name (const struct dirent **a, > const struct dirent **b) > > return strcmp ((*a)->d_name, (*b)->d_name); > > } > > > > +/* Return the type of a directory entry relative to path as a stat(2) > > + * mode. Like stat, this follows symlinks. Returns -1 and sets errno > > + * if the file's type cannot be determined (which includes dangling > > + * symlinks). > > + */ > > +static int > > +dirent_type (const char *path, const struct dirent *entry) > > +{ > > + struct stat statbuf; > > + char *abspath; > > + int err; > > + > > +#ifdef _DIRENT_HAVE_D_TYPE > > + /* Mapping from d_type to stat mode_t. We omit DT_LNK so that > > + * we'll fall through to stat and get the real file type. */ > > + static const mode_t modes[] = { > > + [DT_BLK] = S_IFBLK, > > + [DT_CHR] = S_IFCHR, > > + [DT_DIR] = S_IFDIR, > > + [DT_FIFO] = S_IFIFO, > > + [DT_REG] = S_IFREG, > > + [DT_SOCK] = S_IFSOCK > > + }; > > + if (entry->d_type < sizeof(modes)/sizeof(modes[0]) && > > ARRAY_SIZE() Huh. I went looking for that. I wonder how I missed it. > > + modes[entry->d_type]) > > + return modes[entry->d_type]; > > +#endif > > + > > + abspath = talloc_asprintf (NULL, "%s/%s", path, entry->d_name); > > + if (!abspath) > > + return -1; > > Does talloc set errno in this case? I suspect not. > > > + err = stat(abspath, &statbuf); > > + talloc_free (abspath); > > This likely breaks your promise about errno. You can't trust talloc_free() > not calling some function that sets errno. Setting errno was a late and apparently not well thought-out addition. The new patch should set it on all of the error paths and save it around things that may modify it. > > + if (err < 0) > > + return -1; > > + return statbuf.st_mode & S_IFMT; > > +} > > + > > /* Test if the directory looks like a Maildir directory. > > * > > * Search through the array of directory entries to see if we can find > all > > @@ -162,12 +200,12 @@ dirent_sort_strcmp_name (const struct dirent **a, > const struct dirent **b) > > * Return 1 if the directory looks like a Maildir and 0 otherwise. > > */ > > static int > > -_entries_resemble_maildir (struct dirent **entries, int count) > > +_entries_resemble_maildir (const char *path, struct dirent **entries, > int count) > > { > > int i, found = 0; > > > > for (i = 0; i < count; i++) { > > - if (entries[i]->d_type != DT_DIR && entries[i]->d_type != > DT_UNKNOWN) > > + if (dirent_type (path, entries[i]) != S_IFDIR) > > continue; > > > > if (strcmp(entries[i]->d_name, "new") == 0 || > > @@ -250,7 +288,7 @@ add_files_recursive (notmuch_database_t *notmuch, > > notmuch_status_t status, ret = NOTMUCH_STATUS_SUCCESS; > > notmuch_message_t *message = NULL; > > struct dirent **fs_entries = NULL; > > - int i, num_fs_entries; > > + int i, num_fs_entries, entry_type; > > notmuch_directory_t *directory; > > notmuch_filenames_t *db_files = NULL; > > notmuch_filenames_t *db_subdirs = NULL; > > @@ -317,7 +355,7 @@ add_files_recursive (notmuch_database_t *notmuch, > > } > > > > /* Pass 1: Recurse into all sub-directories. */ > > - is_maildir = _entries_resemble_maildir (fs_entries, > num_fs_entries); > > + is_maildir = _entries_resemble_maildir (path, fs_entries, > num_fs_entries); > > > > for (i = 0; i < num_fs_entries; i++) { > > if (interrupted) > > @@ -325,17 +363,16 @@ add_files_recursive (notmuch_database_t *notmuch, > > > > entry = fs_entries[i]; > > > > - /* We only want to descend into directories. > > - * But symlinks can be to directories too, of course. > > - * > > - * And if the filesystem doesn't tell us the file type in the > > - * scandir results, then it might be a directory (and if not, > > - * then we'll stat and return immediately in the next level of > > - * recursion). */ > > - if (entry->d_type != DT_DIR && > > - entry->d_type != DT_LNK && > > - entry->d_type != DT_UNKNOWN) > > - { > > + /* We only want to descend into directories (and symlinks to > > + * directories). */ > > + entry_type = dirent_type (path, entry); > > + if (entry_type == -1) { > > + /* Be pessimistic, e.g. so we don't loose lots of mail > > s/loose/lose/ ? Oops. > > + * just because a user broke a symlink. */ > > + fprintf (stderr, "Error reading file %s/%s: %s\n", > > + path, entry->d_name, strerror (errno)); > > You can't trust errno here, as explained above. Fixed above. > > + return NOTMUCH_STATUS_FILE_ERROR; > > + } else if (entry_type != S_IFDIR) { > > continue; > > } > > > > @@ -425,31 +462,13 @@ add_files_recursive (notmuch_database_t *notmuch, > > notmuch_filenames_move_to_next (db_subdirs); > > } > > > > - /* If we're looking at a symlink, we only want to add it if it > > - * links to a regular file, (and not to a directory, say). > > - * > > - * Similarly, if the file is of unknown type (due to filesystem > > - * limitations), then we also need to look closer. > > - * > > - * In either case, a stat does the trick. > > - */ > > - if (entry->d_type == DT_LNK || entry->d_type == DT_UNKNOWN) { > > - int err; > > - > > - next = talloc_asprintf (notmuch, "%s/%s", path, > entry->d_name); > > - err = stat (next, &st); > > - talloc_free (next); > > - next = NULL; > > - > > - /* Don't emit an error for a link pointing nowhere, since > > - * the directory-traversal pass will have already done > > - * that. */ > > - if (err) > > - continue; > > - > > - if (! S_ISREG (st.st_mode)) > > - continue; > > - } else if (entry->d_type != DT_REG) { > > + /* Only add regular files (and symlinks to regular files). */ > > + entry_type = dirent_type (path, entry); > > + if (entry_type == -1) { > > + fprintf (stderr, "Error reading file %s/%s: %s\n", > > + path, entry->d_name, strerror (errno)); > > Ditto. > > > + return NOTMUCH_STATUS_FILE_ERROR; > > + } else if (entry_type != S_IFREG) { > > continue; > > } > > > > diff --git a/test/new b/test/new > > index 26253db..e3900f5 100755 > > --- a/test/new > > +++ b/test/new > > @@ -140,7 +140,7 @@ test_begin_subtest "Broken symlink aborts" > > ln -s does-not-exist "${MAIL_DIR}/broken" > > output=$(NOTMUCH_NEW 2>&1) > > test_expect_equal "$output" \ > > -"Error reading directory /run/shm/nm/tmp.new/mail/broken: No such file > or directory > > +"Error reading file /run/shm/nm/tmp.new/mail/broken: No such file or > directory > > Note: A fatal error was encountered: Something went wrong trying to > read or write a file > > No new mail." > > rm "${MAIL_DIR}/broken" > > > > _______________________________________________ > > notmuch mailing list > > [2]notmuch@notmuchmail.org > > [3]http://notmuchmail.org/mailman/listinfo/notmuch