On Tue, Nov 17, 2020 at 04:03:15AM +0000, Daniel Rosenberg wrote: > Expand f2fs's casefolding support to include encrypted directories. To > index casefolded+encrypted directories, we use the SipHash of the > casefolded name, keyed by a key derived from the directory's fscrypt > master key. This ensures that the dirhash doesn't leak information > about the plaintext filenames. > > Encryption keys are unavailable during roll-forward recovery, so we > can't compute the dirhash when recovering a new dentry in an encrypted + > casefolded directory. To avoid having to force a checkpoint when a new > file is fsync'ed, store the dirhash on-disk appended to i_name. > > This patch incorporates work by Eric Biggers <ebiggers@xxxxxxxxxx> > and Jaegeuk Kim <jaegeuk@xxxxxxxxxx>. > > Co-developed-by: Eric Biggers <ebiggers@xxxxxxxxxx> > Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> > Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx> > --- > fs/f2fs/dir.c | 89 +++++++++++++++++++++++++++++++++++++--------- > fs/f2fs/f2fs.h | 8 +++-- > fs/f2fs/hash.c | 11 +++++- > fs/f2fs/inline.c | 4 +++ > fs/f2fs/recovery.c | 12 ++++++- > fs/f2fs/super.c | 6 ---- > 6 files changed, 103 insertions(+), 27 deletions(-) > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > index 71fdf5076461..0adc6bcfb5c0 100644 > --- a/fs/f2fs/dir.c > +++ b/fs/f2fs/dir.c > @@ -5,6 +5,7 @@ > * Copyright (c) 2012 Samsung Electronics Co., Ltd. > * http://www.samsung.com/ > */ > +#include <asm/unaligned.h> > #include <linux/fs.h> > #include <linux/f2fs_fs.h> > #include <linux/sched/signal.h> > @@ -195,26 +196,53 @@ static struct f2fs_dir_entry *find_in_block(struct inode *dir, > { > struct f2fs_dentry_block *dentry_blk; > struct f2fs_dentry_ptr d; > + struct f2fs_dir_entry *res; > > 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); > + res = f2fs_find_target_dentry(&d, fname, max_slots); > + if (IS_ERR(res)) { > + dentry_page = ERR_CAST(res); > + res = NULL; > + } > + return res; > } What is the assignment to dentry_page supposed to be accomplishing? It looks like it's meant to pass up errors from f2fs_find_target_dentry(), but it doesn't do that. > @@ -222,14 +250,20 @@ static bool f2fs_match_ci_name(const struct inode *dir, const struct qstr *name, > * fall back to treating them as opaque byte sequences. > */ > if (sb_has_strict_encoding(sb) || name->len != entry.len) > - return false; > - return !memcmp(name->name, entry.name, name->len); > + res = 0; > + else > + res = memcmp(name->name, entry.name, name->len) == 0; > + } else { > + /* utf8_strncasecmp_folded returns 0 on match */ > + res = (res == 0); > } The following might be easier to understand: /* * In strict mode, ignore invalid names. In non-strict mode, fall back * to treating them as opaque byte sequences. */ if (res < 0 && !sb_has_strict_encoding(sb)) { res = name->len == entry.len && memcmp(name->name, entry.name, name->len) == 0; } else { /* utf8_strncasecmp_folded returns 0 on match */ res = (res == 0); } > @@ -273,10 +308,14 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, > continue; > } > > - if (de->hash_code == fname->hash && > - f2fs_match_name(d->inode, fname, d->filename[bit_pos], > - le16_to_cpu(de->name_len))) > - goto found; > + if (de->hash_code == fname->hash) { > + res = f2fs_match_name(d->inode, fname, d->filename[bit_pos], > + le16_to_cpu(de->name_len)); > + if (res < 0) > + return ERR_PTR(res); > + else if (res) > + goto found; > + } Overly long line here. Also 'else if' is unnecessary, just use 'if'. - Eric
