From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id B91E0BE71 for ; Fri, 11 Aug 2023 10:26:24 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id A1D54A8CE for ; Fri, 11 Aug 2023 10:26:24 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Fri, 11 Aug 2023 10:26:23 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 59B1145F20 for ; Fri, 11 Aug 2023 10:26:23 +0200 (CEST) Date: Fri, 11 Aug 2023 10:26:21 +0200 From: Wolfgang Bumiller To: Gabriel Goller Cc: pbs-devel@lists.proxmox.com Message-ID: References: <20230809101913.81818-1-g.goller@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230809101913.81818-1-g.goller@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL 0.106 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pbs-devel] [PATCH pathpatterns] match_list: added `matches_path()` function, which matches only the path X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Aug 2023 08:26:24 -0000 On Wed, Aug 09, 2023 at 12:19:12PM +0200, Gabriel Goller wrote: > Added `matches_path()` function, which only matches against the path and returns > an error if a file_mode pattern is found/needed in the matching list. This is > useful when we want to check if a file is excluded before running `stat()` on > the file to get the file_mode (which could fail). > > Signed-off-by: Gabriel Goller > --- > src/match_list.rs | 159 +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 158 insertions(+), 1 deletion(-) > > diff --git a/src/match_list.rs b/src/match_list.rs > index c5b14e0..acad328 100644 > --- a/src/match_list.rs > +++ b/src/match_list.rs > @@ -1,6 +1,6 @@ > //! Helpers for include/exclude lists. > - > use bitflags::bitflags; > +use std::fmt; > > use crate::PatternFlag; > > @@ -39,6 +39,17 @@ impl Default for MatchFlag { > } > } > > +#[derive(Debug, PartialEq)] > +pub struct FileModeRequiredForMatching; Let's shorten this to just `FileModeRequired` ;-) > + > +impl fmt::Display for FileModeRequiredForMatching { > + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { > + write!(f, "File mode is required for matching") > + } > +} > + > +impl std::error::Error for FileModeRequiredForMatching {} > + > /// A pattern entry. (Glob patterns or literal patterns.) > // Note: > // For regex we'd likely use the POSIX extended REs via `regexec(3)`, since we're targetting > @@ -304,12 +315,32 @@ impl MatchEntry { > > self.matches_path_exact(path) > } > + > + /// Check whether the path contains a matching suffix. Returns an error if a file mode is required. > + pub fn matches_path>( > + &self, > + path: T, > + ) -> Result { > + self.matches_path_do(path.as_ref()) > + } > + > + fn matches_path_do(&self, path: &[u8]) -> Result { > + if !self.flags.contains(MatchFlag::ANY_FILE_TYPE) { > + return Err(FileModeRequiredForMatching); > + } > + > + Ok(self.matches_path_suffix_do(path)) > + } > } > > #[doc(hidden)] > pub trait MatchListEntry { > fn entry_matches(&self, path: &[u8], file_mode: Option) -> Option; > fn entry_matches_exact(&self, path: &[u8], file_mode: Option) -> Option; > + fn entry_matches_path( > + &self, > + path: &[u8], > + ) -> Result, FileModeRequiredForMatching>; > } > > impl MatchListEntry for &'_ MatchEntry { > @@ -328,6 +359,21 @@ impl MatchListEntry for &'_ MatchEntry { > None > } > } > + > + fn entry_matches_path( > + &self, > + path: &[u8], > + ) -> Result, FileModeRequiredForMatching> { > + if let Ok(b) = self.matches_path(path) { This can just use `?`, it's the exact same error type after all. (Also `if let Ok` is generally best avoided since the 'else' branch discards the error, and if not, it's often a case like this where it can juse use '?' ;-) ). Effectively this could be as short as Ok(self.matches_path(path)?.then(|| self.match_type())) > + if b { As an additional hint: when you nest ifs around things you can match, you can just include both cases in the patterns: match self.matches_path(path) { Ok(true) => Ok(Some(self.match_type())), Ok(false) => Ok(None), Err(err) => Err(err), // where this Err() case already tells you that you can use '?' instead } > + Ok(Some(self.match_type())) > + } else { > + Ok(None) > + } > + } else { > + Err(FileModeRequiredForMatching) > + } > + } > } > > impl MatchListEntry for &'_ &'_ MatchEntry { > @@ -346,6 +392,21 @@ impl MatchListEntry for &'_ &'_ MatchEntry { > None > } > } > + > + fn entry_matches_path( > + &self, > + path: &[u8], > + ) -> Result, FileModeRequiredForMatching> { same > + if let Ok(b) = self.matches_path(path) { > + if b { > + Ok(Some(self.match_type())) > + } else { > + Ok(None) > + } > + } else { > + Err(FileModeRequiredForMatching) > + } > + } > } > > /// This provides [`matches`](MatchList::matches) and [`matches_exact`](MatchList::matches_exact) > @@ -374,6 +435,20 @@ pub trait MatchList { > } > > fn matches_exact_do(&self, path: &[u8], file_mode: Option) -> Option; > + > + /// Check whether this list contains anything exactly matching the path, returns error if > + /// `file_mode` is required for exact matching. > + fn matches_path>( > + &self, > + path: T, > + ) -> Result, FileModeRequiredForMatching> { > + self.matches_path_do(path.as_ref()) > + } > + > + fn matches_path_do( > + &self, > + path: &[u8], > + ) -> Result, FileModeRequiredForMatching>; > } > > impl<'a, T> MatchList for T > @@ -408,6 +483,24 @@ where > > None > } > + > + fn matches_path_do( > + &self, > + path: &[u8], > + ) -> Result, FileModeRequiredForMatching> { Given the amount of tiny match helpers we run through with those 2 traits already I wonder if we should just make a breaking change here instead and only have the versions with the `Result` while users (or defaulted helpers in the trait) just pass `file_mode.unwrap_or(!0)` (since a mode of 0 should match anything ;-) ). But I don't have any strong feelings about this, so either way is fine with me. > + // This is an &self method on a `T where T: 'a`. > + let this: &'a Self = unsafe { std::mem::transmute(self) }; > + > + for m in this.into_iter().rev() { > + if let Ok(mt) = m.entry_matches_path(path) { IIRC the intention was actually to immediately fail if we hit a pattern with a file mode, since we wouldn't be able to tell if it would already exclude the file, otherwise we really *could* just skip this entirely and have a failing stat() call just use `Some(!0)` as file mode. Basically, if the user runs into an inaccessible file they have to append `--exclude=/that/one/file` to the CLI invocation to fix it, whereas otherwise they'd still get an error. So this should just be if let Some(mt) = m.entry_matches_path(path)? { return Some(mt); } > + if mt.is_some() { > + return Ok(mt); > + } > + } > + } > + > + Err(FileModeRequiredForMatching) Also this is wrong. If nothing matches, nothing matches ;-) (just like in the other matching variants). Which immediately tells you that skipping the error above doesn't make much sense :-) )