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 A5EE8C693 for ; Mon, 14 Aug 2023 11:33:22 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 7E784BBA for ; Mon, 14 Aug 2023 11:32:52 +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)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Mon, 14 Aug 2023 11:32:51 +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 7DDB2473DC for ; Mon, 14 Aug 2023 11:32:51 +0200 (CEST) Message-ID: Date: Mon, 14 Aug 2023 11:32:50 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.1 To: Wolfgang Bumiller Cc: pbs-devel@lists.proxmox.com References: <20230809101913.81818-1-g.goller@proxmox.com> Content-Language: en-US From: Gabriel Goller In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.643 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 NICE_REPLY_A -2.265 Looks like a legit reply (A) 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: Mon, 14 Aug 2023 09:33:22 -0000 On 8/11/23 10:26, Wolfgang Bumiller wrote: > 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` ;-) Agree >> + >> +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. Hmm, I don't get what you mean by the `versions with the Result`? Do you mean we should just modify the `matches()` and `matches_exact()` function to return a `Result` if the mode is `ANY_FILE_TYPE` and we need one (a file mode) to match? >> + // 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); > } Hmm, my solution would have been to traverse all the patterns with a `ANY_FILE_TYPE` mode and if there is a match, nice, return. If there is no match, check if there are other patterns without the `ANY_FILE_TYPE` mode (then we need to fail because we don't know the `file_mode` yet...) or return nothing if there are no patterns left. I don't know if this is the correct approach though... >> + 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 :-) ) Yes, you are right, corrected it.