From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E476482ED for ; Mon, 23 Dec 2024 17:14:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734974078; cv=none; b=mSWaK0MCFTc0sb7UOKPsMa0Jo7c+igpFRjMNbnUqfN4g4NcGa7r2VEUuVLLbWfejOrMTfxp8cLJ98eVVMuGWZ1K4lntQbyzoBeNiHV+oj8RaoyFWSJ2Z45s6VyEvsh1uJjdmusHaZmmlsbq6fzPgGX/MrDHJ+PmjH5J+jTptj9Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734974078; c=relaxed/simple; bh=lBf5j+nAJ+aznIwILJNNIhQhMeZX1ZghKCcxXoJMZTY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iG2rb986z+SpWDaAcaz4+ZSAdhv44hNm+IwuHKCbZtmmW9vpO3R9/CD9bg5DdUY+hYL97tmqvKCqgq7yc59hk/U1MN67HcPxsmO32zQQYwuysAUE+IajoinHnlLR6YNu0wk7XphsQzX/T3NBeB8UVMRrSMk1V6zV6rrCJ0CZnq8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B/kFAW48; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B/kFAW48" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CDCFC4CED3; Mon, 23 Dec 2024 17:14:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734974078; bh=lBf5j+nAJ+aznIwILJNNIhQhMeZX1ZghKCcxXoJMZTY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B/kFAW48fVecv0vUYXUq3KjNudFT8szML662G/LA0dQv99EMQmE3mrCxITBqMlDiS b/RznaZ2BFaqFvjCcJ4bm9FG5JPCyzpSiyytHm5R08ITajoLPk+R6/W87aa6SvrRPr b9R5VaeW4GCBoxCRXq8Kr83A2tazEMI4Eqy7v85zZaaKtaak+qs1/PGtg2jwBE0XkK Zukrn80S9Qbe24uJbN1Uo+idQRxD1pE4/QNwI0UGlkFtlda+Yk9faAPb5dixRejoDr YIKYHMQHRXbZwDVSfL4UjZxsHLzGaZjjUH8CKJRku8+Gp+P/y/VsfdwcI4NMqNXki8 V/Ssxx3xc6akw== Date: Mon, 23 Dec 2024 17:14:36 +0000 From: Jaegeuk Kim To: Chao Yu Cc: Daniel Lee , linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] f2fs: Introduce linear search for dentries Message-ID: References: <20241220234131.1089833-1-chullee@google.com> <4f6e5f65-117d-4459-905e-94d8a71d36ff@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4f6e5f65-117d-4459-905e-94d8a71d36ff@kernel.org> On 12/22, Chao Yu wrote: > On 2024/12/21 7:41, Daniel Lee wrote: > > This patch addresses an issue where some files in case-insensitive > > directories become inaccessible due to changes in how the kernel function, > > utf8_casefold(), generates case-folded strings from the commit 5c26d2f1d3f5 > > ("unicode: Don't special case ignorable code points"). > > > > F2FS uses these case-folded names to calculate hash values for locating > > dentries and stores them on disk. Since utf8_casefold() can produce > > different output across kernel versions, stored hash values and newly > > calculated hash values may differ. This results in affected files no > > longer being found via the hash-based lookup. > > > > To resolve this, the patch introduces a linear search fallback. > > If the initial hash-based search fails, F2FS will sequentially scan the > > directory entries. > > > > Fixes: 5c26d2f1d3f5 ("unicode: Don't special case ignorable code points") > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=219586 > > Signed-off-by: Daniel Lee > > --- > > v3: > > - Fix the unused label warning > > v2: > > - Only update chash if use_hash is true > > fs/f2fs/dir.c | 42 +++++++++++++++++++++++++++++++----------- > > fs/f2fs/f2fs.h | 6 ++++-- > > fs/f2fs/inline.c | 5 +++-- > > 3 files changed, 38 insertions(+), 15 deletions(-) > > > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > > index 47a5c806cf16..058b8be9a373 100644 > > --- a/fs/f2fs/dir.c > > +++ b/fs/f2fs/dir.c > > @@ -175,7 +175,8 @@ static unsigned long dir_block_index(unsigned int level, > > static struct f2fs_dir_entry *find_in_block(struct inode *dir, > > struct page *dentry_page, > > const struct f2fs_filename *fname, > > - int *max_slots) > > + int *max_slots, > > + bool use_hash) > > { > > struct f2fs_dentry_block *dentry_blk; > > struct f2fs_dentry_ptr d; > > @@ -183,7 +184,7 @@ static struct f2fs_dir_entry *find_in_block(struct inode *dir, > > dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page); > > make_dentry_ptr_block(dir, &d, dentry_blk); > > - return f2fs_find_target_dentry(&d, fname, max_slots); > > + return f2fs_find_target_dentry(&d, fname, max_slots, use_hash); > > } > > static inline int f2fs_match_name(const struct inode *dir, > > @@ -208,7 +209,8 @@ static inline int f2fs_match_name(const struct inode *dir, > > } > > struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, > > - const struct f2fs_filename *fname, int *max_slots) > > + const struct f2fs_filename *fname, int *max_slots, > > + bool use_hash) > > { > > struct f2fs_dir_entry *de; > > unsigned long bit_pos = 0; > > @@ -231,7 +233,7 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, > > continue; > > } > > - if (de->hash_code == fname->hash) { > > + if (!use_hash || de->hash_code == fname->hash) { > > res = f2fs_match_name(d->inode, fname, > > d->filename[bit_pos], > > le16_to_cpu(de->name_len)); > > @@ -258,11 +260,12 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, > > static struct f2fs_dir_entry *find_in_level(struct inode *dir, > > unsigned int level, > > const struct f2fs_filename *fname, > > - struct page **res_page) > > + struct page **res_page, > > + bool use_hash) > > { > > int s = GET_DENTRY_SLOTS(fname->disk_name.len); > > unsigned int nbucket, nblock; > > - unsigned int bidx, end_block; > > + unsigned int bidx, end_block, bucket_no; > > struct page *dentry_page; > > struct f2fs_dir_entry *de = NULL; > > pgoff_t next_pgofs; > > @@ -272,8 +275,11 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > > nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); > > nblock = bucket_blocks(level); > > + bucket_no = use_hash ? le32_to_cpu(fname->hash) % nbucket : 0; > > + > > +start_find_bucket: > > bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, > > - le32_to_cpu(fname->hash) % nbucket); > > + bucket_no); > > end_block = bidx + nblock; > > while (bidx < end_block) { > > @@ -290,7 +296,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > > } > > } > > - de = find_in_block(dir, dentry_page, fname, &max_slots); > > + de = find_in_block(dir, dentry_page, fname, &max_slots, use_hash); > > if (IS_ERR(de)) { > > *res_page = ERR_CAST(de); > > de = NULL; > > @@ -307,7 +313,10 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > > bidx++; > > } > > - if (!de && room && F2FS_I(dir)->chash != fname->hash) { > > + if (!use_hash && !de && ++bucket_no < nbucket) > > + goto start_find_bucket; > > + > > + if (use_hash && !de && room && F2FS_I(dir)->chash != fname->hash) { > > F2FS_I(dir)->chash = fname->hash; > > F2FS_I(dir)->clevel = level; > > What about cleaning up w/ > > if (de) > return de; > > if (use_hash) { Applied w/ if (likely(use_hash)) { Thanks, > if (room && F2FS_I(dir)->chash != fname->hash) { > ... > } > } else if (++bucket_no < nbucket) > goto start_find_bucket; > } > return NULL; > > Otherwise, it looks good to me, anyway, > > Reviewed-by: Chao Yu > > Thanks, > > > } > > @@ -323,11 +332,15 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > > struct f2fs_dir_entry *de = NULL; > > unsigned int max_depth; > > unsigned int level; > > + bool use_hash = true; > > *res_page = NULL; > > +#if IS_ENABLED(CONFIG_UNICODE) > > +start_find_entry: > > +#endif > > if (f2fs_has_inline_dentry(dir)) { > > - de = f2fs_find_in_inline_dir(dir, fname, res_page); > > + de = f2fs_find_in_inline_dir(dir, fname, res_page, use_hash); > > goto out; > > } > > @@ -343,11 +356,18 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > > } > > for (level = 0; level < max_depth; level++) { > > - de = find_in_level(dir, level, fname, res_page); > > + de = find_in_level(dir, level, fname, res_page, use_hash); > > if (de || IS_ERR(*res_page)) > > break; > > } > > + > > out: > > +#if IS_ENABLED(CONFIG_UNICODE) > > + if (IS_CASEFOLDED(dir) && !de && use_hash) { > > + use_hash = false; > > + goto start_find_entry; > > + } > > +#endif > > /* This is to increase the speed of f2fs_create */ > > if (!de) > > F2FS_I(dir)->task = current; > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index f523dd302bf6..1afebb9c4061 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -3588,7 +3588,8 @@ int f2fs_prepare_lookup(struct inode *dir, struct dentry *dentry, > > struct f2fs_filename *fname); > > void f2fs_free_filename(struct f2fs_filename *fname); > > struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, > > - const struct f2fs_filename *fname, int *max_slots); > > + const struct f2fs_filename *fname, int *max_slots, > > + bool use_hash); > > int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, > > unsigned int start_pos, struct fscrypt_str *fstr); > > void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent, > > @@ -4224,7 +4225,8 @@ int f2fs_write_inline_data(struct inode *inode, struct folio *folio); > > int f2fs_recover_inline_data(struct inode *inode, struct page *npage); > > struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, > > const struct f2fs_filename *fname, > > - struct page **res_page); > > + struct page **res_page, > > + bool use_hash); > > int f2fs_make_empty_inline_dir(struct inode *inode, struct inode *parent, > > struct page *ipage); > > int f2fs_add_inline_entry(struct inode *dir, const struct f2fs_filename *fname, > > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > > index cbd2a0d34804..3e3c35d4c98b 100644 > > --- a/fs/f2fs/inline.c > > +++ b/fs/f2fs/inline.c > > @@ -352,7 +352,8 @@ int f2fs_recover_inline_data(struct inode *inode, struct page *npage) > > struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, > > const struct f2fs_filename *fname, > > - struct page **res_page) > > + struct page **res_page, > > + bool use_hash) > > { > > struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb); > > struct f2fs_dir_entry *de; > > @@ -369,7 +370,7 @@ struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, > > inline_dentry = inline_data_addr(dir, ipage); > > make_dentry_ptr_inline(dir, &d, inline_dentry); > > - de = f2fs_find_target_dentry(&d, fname, NULL); > > + de = f2fs_find_target_dentry(&d, fname, NULL, use_hash); > > unlock_page(ipage); > > if (IS_ERR(de)) { > > *res_page = ERR_CAST(de);