On Thu, Dec 19, 2024 at 5:29 AM Chao Yu <c...@kernel.org> wrote:
>
> Hi Daniel,
>
> On 2024/12/17 15:55, 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.
> >
>
> Need a fixes line?Thanks. I will add the commit 5c26d2f1d3f5 to the Fixes: > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=219586 > > Signed-off-by: Daniel Lee <chul...@google.com> > > --- > > fs/f2fs/dir.c | 38 ++++++++++++++++++++++++++++---------- > > fs/f2fs/f2fs.h | 6 ++++-- > > fs/f2fs/inline.c | 5 +++-- > > 3 files changed, 35 insertions(+), 14 deletions(-) > > > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > > index 47a5c806cf16..a85d19b4e178 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; > > @@ -307,6 +313,9 @@ static struct f2fs_dir_entry *find_in_level(struct > > inode *dir, > > bidx++; > > } > > > > + if (!use_hash && !de && ++bucket_no < nbucket) > > + goto start_find_bucket; > > + > > if (!de && room && F2FS_I(dir)->chash != fname->hash) { > > Do we need to avoid accessing or assigning hash if use_hash is false? > Is it still worth keeping the hash for the creation if both hash-based and linear searches failed? > Thanks, > > > F2FS_I(dir)->chash = fname->hash; > > F2FS_I(dir)->clevel = level; > > @@ -323,11 +332,13 @@ 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; > > > > +start_find_entry: > > 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 +354,18 @@ 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); > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
