These patches are on top of the torvalds tree.
F2FS currently supports casefolding and encryption, but not at
the same time. These patches aim to rectify that. In a later follow up,
this will be added for Ext4 as well. I've included one ext4 patch from
the previous set since it isn't in the f2fs branch, but is needed for the
fscrypt changes.
The f2fs-tools changes have already been applied.
Since both fscrypt and casefolding require their own dentry operations,
I've moved the responsibility of setting the dentry operations from fscrypt
to the filesystems and provided helper functions that should work for most
cases.
These are a follow-up to the previously sent patch set
"[PATCH v12 0/4] Prepare for upcoming Casefolding/Encryption patches"
v2:
Simplified generic dentry_op function
Passed through errors in f2fs_match_ci_name
Daniel Rosenberg (3):
libfs: Add generic function for setting dentry_ops
fscrypt: Have filesystems handle their d_ops
f2fs: Handle casefolding with Encryption
fs/crypto/fname.c | 4 --
fs/crypto/hooks.c | 1 -
fs/ext4/dir.c | 7 ---
fs/ext4/ext4.h | 4 --
fs/ext4/namei.c | 1 +
fs/ext4/super.c | 5 ---
fs/f2fs/dir.c | 96 +++++++++++++++++++++++++++++++----------
fs/f2fs/f2fs.h | 11 +++--
fs/f2fs/hash.c | 11 ++++-
fs/f2fs/inline.c | 4 ++
fs/f2fs/namei.c | 1 +
fs/f2fs/recovery.c | 12 +++++-
fs/f2fs/super.c | 7 ---
fs/libfs.c | 60 ++++++++++++++++++++++++++
fs/ubifs/dir.c | 1 +
include/linux/fs.h | 1 +
include/linux/fscrypt.h | 5 ++-
17 files changed, 170 insertions(+), 61 deletions(-)
--
2.29.2.299.gdc1121823c-goog
This shifts the responsibility of setting up dentry operations from
fscrypt to the individual filesystems, allowing them to have their own
operations while still setting fscrypt's d_revalidate as appropriate.
Most filesystems can just use generic_set_encrypted_ci_d_ops, unless
they have their own specific dentry operations as well. That operation
will set the minimal d_ops required under the circumstances.
Since the fscrypt d_ops are set later on, we must set all d_ops there,
since we cannot adjust those later on. This should not result in any
change in behavior.
Signed-off-by: Daniel Rosenberg <[email protected]>
---
fs/crypto/fname.c | 4 ----
fs/crypto/hooks.c | 1 -
fs/ext4/dir.c | 7 -------
fs/ext4/ext4.h | 4 ----
fs/ext4/namei.c | 1 +
fs/ext4/super.c | 5 -----
fs/f2fs/dir.c | 7 -------
fs/f2fs/f2fs.h | 3 ---
fs/f2fs/namei.c | 1 +
fs/f2fs/super.c | 1 -
fs/ubifs/dir.c | 1 +
include/linux/fscrypt.h | 5 +++--
12 files changed, 6 insertions(+), 34 deletions(-)
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 1fbe6c24d705..cb3cfa6329ba 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -570,7 +570,3 @@ int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
return valid;
}
EXPORT_SYMBOL_GPL(fscrypt_d_revalidate);
-
-const struct dentry_operations fscrypt_d_ops = {
- .d_revalidate = fscrypt_d_revalidate,
-};
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 20b0df47fe6a..9006fa983335 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -117,7 +117,6 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_NOKEY_NAME;
spin_unlock(&dentry->d_lock);
- d_set_d_op(dentry, &fscrypt_d_ops);
}
return err;
}
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index ca50c90adc4c..e757319a4472 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -667,10 +667,3 @@ const struct file_operations ext4_dir_operations = {
.open = ext4_dir_open,
.release = ext4_release_dir,
};
-
-#ifdef CONFIG_UNICODE
-const struct dentry_operations ext4_dentry_ops = {
- .d_hash = generic_ci_d_hash,
- .d_compare = generic_ci_d_compare,
-};
-#endif
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index bf9429484462..ad77f01d9e20 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3380,10 +3380,6 @@ static inline void ext4_unlock_group(struct super_block *sb,
/* dir.c */
extern const struct file_operations ext4_dir_operations;
-#ifdef CONFIG_UNICODE
-extern const struct dentry_operations ext4_dentry_ops;
-#endif
-
/* file.c */
extern const struct inode_operations ext4_file_inode_operations;
extern const struct file_operations ext4_file_operations;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 33509266f5a0..12a417ff5648 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1614,6 +1614,7 @@ static struct buffer_head *ext4_lookup_entry(struct inode *dir,
struct buffer_head *bh;
err = ext4_fname_prepare_lookup(dir, dentry, &fname);
+ generic_set_encrypted_ci_d_ops(dentry);
if (err == -ENOENT)
return NULL;
if (err)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6633b20224d5..0288bedf46e1 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4968,11 +4968,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto failed_mount4;
}
-#ifdef CONFIG_UNICODE
- if (sb->s_encoding)
- sb->s_d_op = &ext4_dentry_ops;
-#endif
-
sb->s_root = d_make_root(root);
if (!sb->s_root) {
ext4_msg(sb, KERN_ERR, "get root dentry failed");
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 4b9ef8bbfa4a..71fdf5076461 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -1099,10 +1099,3 @@ const struct file_operations f2fs_dir_operations = {
.compat_ioctl = f2fs_compat_ioctl,
#endif
};
-
-#ifdef CONFIG_UNICODE
-const struct dentry_operations f2fs_dentry_ops = {
- .d_hash = generic_ci_d_hash,
- .d_compare = generic_ci_d_compare,
-};
-#endif
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index cb700d797296..62b4f31d30e2 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3767,9 +3767,6 @@ static inline void f2fs_update_sit_info(struct f2fs_sb_info *sbi) {}
#endif
extern const struct file_operations f2fs_dir_operations;
-#ifdef CONFIG_UNICODE
-extern const struct dentry_operations f2fs_dentry_ops;
-#endif
extern const struct file_operations f2fs_file_operations;
extern const struct inode_operations f2fs_file_inode_operations;
extern const struct address_space_operations f2fs_dblock_aops;
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 8fa37d1434de..6edb1ab579a1 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -497,6 +497,7 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
}
err = f2fs_prepare_lookup(dir, dentry, &fname);
+ generic_set_encrypted_ci_d_ops(dentry);
if (err == -ENOENT)
goto out_splice;
if (err)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 00eff2f51807..f51d52591c99 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3427,7 +3427,6 @@ static int f2fs_setup_casefold(struct f2fs_sb_info *sbi)
sbi->sb->s_encoding = encoding;
sbi->sb->s_encoding_flags = encoding_flags;
- sbi->sb->s_d_op = &f2fs_dentry_ops;
}
#else
if (f2fs_sb_has_casefold(sbi)) {
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 155521e51ac5..7a920434d741 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -203,6 +203,7 @@ static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);
err = fscrypt_prepare_lookup(dir, dentry, &nm);
+ generic_set_encrypted_ci_d_ops(dentry);
if (err == -ENOENT)
return d_splice_alias(NULL, dentry);
if (err)
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index a8f7a43f031b..df2c66ca370e 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -741,8 +741,9 @@ static inline int fscrypt_prepare_rename(struct inode *old_dir,
* directory's encryption key is available, then the lookup is assumed to be by
* plaintext name; otherwise, it is assumed to be by no-key name.
*
- * This also installs a custom ->d_revalidate() method which will invalidate the
- * dentry if it was created without the key and the key is later added.
+ * After calling this function, a filesystem should ensure that its dentry
+ * operations contain fscrypt_d_revalidate if DCACHE_ENCRYPTED_NAME was set,
+ * so that the dentry can be invalidated if the key is later added.
*
* Return: 0 on success; -ENOENT if the directory's key is unavailable but the
* filename isn't a valid no-key name, so a negative dentry should be created;
--
2.29.2.299.gdc1121823c-goog
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 <[email protected]>
and Jaegeuk Kim <[email protected]>.
Co-developed-by: Eric Biggers <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Daniel Rosenberg <[email protected]>
---
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;
}
#ifdef CONFIG_UNICODE
/*
* Test whether a case-insensitive directory entry matches the filename
* being searched for.
+ *
+ * Returns 1 for a match, 0 for no match, and -errno on an error.
*/
-static bool f2fs_match_ci_name(const struct inode *dir, const struct qstr *name,
+static int f2fs_match_ci_name(const struct inode *dir, const struct qstr *name,
const u8 *de_name, u32 de_name_len)
{
const struct super_block *sb = dir->i_sb;
const struct unicode_map *um = sb->s_encoding;
+ struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len);
struct qstr entry = QSTR_INIT(de_name, de_name_len);
int res;
+ if (IS_ENCRYPTED(dir)) {
+ const struct fscrypt_str encrypted_name =
+ FSTR_INIT((u8 *)de_name, de_name_len);
+
+ if (WARN_ON_ONCE(!fscrypt_has_encryption_key(dir)))
+ return -EINVAL;
+
+ decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL);
+ if (!decrypted_name.name)
+ return -ENOMEM;
+ res = fscrypt_fname_disk_to_usr(dir, 0, 0, &encrypted_name,
+ &decrypted_name);
+ if (res < 0)
+ goto out;
+ entry.name = decrypted_name.name;
+ entry.len = decrypted_name.len;
+ }
+
res = utf8_strncasecmp_folded(um, name, &entry);
if (res < 0) {
/*
@@ -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);
}
- return res == 0;
+out:
+ kfree(decrypted_name.name);
+ return res;
}
#endif /* CONFIG_UNICODE */
-static inline bool f2fs_match_name(const struct inode *dir,
+static inline int f2fs_match_name(const struct inode *dir,
const struct f2fs_filename *fname,
const u8 *de_name, u32 de_name_len)
{
@@ -256,6 +290,7 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d,
struct f2fs_dir_entry *de;
unsigned long bit_pos = 0;
int max_len = 0;
+ int res = 0;
if (max_slots)
*max_slots = 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;
+ }
if (max_slots && max_len > *max_slots)
*max_slots = max_len;
@@ -448,17 +487,39 @@ void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
f2fs_put_page(page, 1);
}
-static void init_dent_inode(const struct f2fs_filename *fname,
+static void init_dent_inode(struct inode *dir, struct inode *inode,
+ const struct f2fs_filename *fname,
struct page *ipage)
{
struct f2fs_inode *ri;
+ if (!fname) /* tmpfile case? */
+ return;
+
f2fs_wait_on_page_writeback(ipage, NODE, true, true);
/* copy name info. to this inode page */
ri = F2FS_INODE(ipage);
ri->i_namelen = cpu_to_le32(fname->disk_name.len);
memcpy(ri->i_name, fname->disk_name.name, fname->disk_name.len);
+ if (IS_ENCRYPTED(dir)) {
+ file_set_enc_name(inode);
+ /*
+ * Roll-forward recovery doesn't have encryption keys available,
+ * so it can't compute the dirhash for encrypted+casefolded
+ * filenames. Append it to i_name if possible. Else, disable
+ * roll-forward recovery of the dentry (i.e., make fsync'ing the
+ * file force a checkpoint) by setting LOST_PINO.
+ */
+ if (IS_CASEFOLDED(dir)) {
+ if (fname->disk_name.len + sizeof(f2fs_hash_t) <=
+ F2FS_NAME_LEN)
+ put_unaligned(fname->hash, (f2fs_hash_t *)
+ &ri->i_name[fname->disk_name.len]);
+ else
+ file_lost_pino(inode);
+ }
+ }
set_page_dirty(ipage);
}
@@ -541,11 +602,7 @@ struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir,
return page;
}
- if (fname) {
- init_dent_inode(fname, page);
- if (IS_ENCRYPTED(dir))
- file_set_enc_name(inode);
- }
+ init_dent_inode(dir, inode, fname, page);
/*
* This file should be checkpointed during fsync.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 62b4f31d30e2..878308736761 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -533,9 +533,11 @@ struct f2fs_filename {
#ifdef CONFIG_UNICODE
/*
* For casefolded directories: the casefolded name, but it's left NULL
- * if the original name is not valid Unicode or if the filesystem is
- * doing an internal operation where usr_fname is also NULL. In these
- * cases we fall back to treating the name as an opaque byte sequence.
+ * if the original name is not valid Unicode, if the directory is both
+ * casefolded and encrypted and its encryption key is unavailable, or if
+ * the filesystem is doing an internal operation where usr_fname is also
+ * NULL. In all these cases we fall back to treating the name as an
+ * opaque byte sequence.
*/
struct fscrypt_str cf_name;
#endif
diff --git a/fs/f2fs/hash.c b/fs/f2fs/hash.c
index de841aaf3c43..e3beac546c63 100644
--- a/fs/f2fs/hash.c
+++ b/fs/f2fs/hash.c
@@ -111,7 +111,9 @@ void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname)
* If the casefolded name is provided, hash it instead of the
* on-disk name. If the casefolded name is *not* provided, that
* should only be because the name wasn't valid Unicode, so fall
- * back to treating the name as an opaque byte sequence.
+ * back to treating the name as an opaque byte sequence. Note
+ * that to handle encrypted directories, the fallback must use
+ * usr_fname (plaintext) rather than disk_name (ciphertext).
*/
WARN_ON_ONCE(!fname->usr_fname->name);
if (fname->cf_name.name) {
@@ -121,6 +123,13 @@ void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname)
name = fname->usr_fname->name;
len = fname->usr_fname->len;
}
+ if (IS_ENCRYPTED(dir)) {
+ struct qstr tmp = QSTR_INIT(name, len);
+
+ fname->hash =
+ cpu_to_le32(fscrypt_fname_siphash(dir, &tmp));
+ return;
+ }
}
#endif
fname->hash = cpu_to_le32(TEA_hash_name(name, len));
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 70384e31788d..92e9852d316a 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -332,6 +332,10 @@ struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir,
make_dentry_ptr_inline(dir, &d, inline_dentry);
de = f2fs_find_target_dentry(&d, fname, NULL);
unlock_page(ipage);
+ if (IS_ERR(de)) {
+ *res_page = ERR_CAST(de);
+ de = NULL;
+ }
if (de)
*res_page = ipage;
else
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 4f12ade6410a..0947d36af1a8 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.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 "f2fs.h"
@@ -128,7 +129,16 @@ static int init_recovered_filename(const struct inode *dir,
}
/* Compute the hash of the filename */
- if (IS_CASEFOLDED(dir)) {
+ if (IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir)) {
+ /*
+ * In this case the hash isn't computable without the key, so it
+ * was saved on-disk.
+ */
+ if (fname->disk_name.len + sizeof(f2fs_hash_t) > F2FS_NAME_LEN)
+ return -EINVAL;
+ fname->hash = get_unaligned((f2fs_hash_t *)
+ &raw_inode->i_name[fname->disk_name.len]);
+ } else if (IS_CASEFOLDED(dir)) {
err = f2fs_init_casefolded_name(dir, fname);
if (err)
return err;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f51d52591c99..42293b7ceaf2 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3399,12 +3399,6 @@ static int f2fs_setup_casefold(struct f2fs_sb_info *sbi)
struct unicode_map *encoding;
__u16 encoding_flags;
- if (f2fs_sb_has_encrypt(sbi)) {
- f2fs_err(sbi,
- "Can't mount with encoding and encryption");
- return -EINVAL;
- }
-
if (f2fs_sb_read_encoding(sbi->raw_super, &encoding_info,
&encoding_flags)) {
f2fs_err(sbi,
--
2.29.2.299.gdc1121823c-goog
On Tue, Nov 17, 2020 at 04:03:14AM +0000, Daniel Rosenberg wrote:
> This shifts the responsibility of setting up dentry operations from
> fscrypt to the individual filesystems, allowing them to have their own
> operations while still setting fscrypt's d_revalidate as appropriate.
>
> Most filesystems can just use generic_set_encrypted_ci_d_ops, unless
> they have their own specific dentry operations as well. That operation
> will set the minimal d_ops required under the circumstances.
>
> Since the fscrypt d_ops are set later on, we must set all d_ops there,
> since we cannot adjust those later on. This should not result in any
> change in behavior.
>
> Signed-off-by: Daniel Rosenberg <[email protected]>
Acked-by: Theodore Ts'o <[email protected]>
On 11/17, Theodore Y. Ts'o wrote:
> On Tue, Nov 17, 2020 at 04:03:14AM +0000, Daniel Rosenberg wrote:
> > This shifts the responsibility of setting up dentry operations from
> > fscrypt to the individual filesystems, allowing them to have their own
> > operations while still setting fscrypt's d_revalidate as appropriate.
> >
> > Most filesystems can just use generic_set_encrypted_ci_d_ops, unless
> > they have their own specific dentry operations as well. That operation
> > will set the minimal d_ops required under the circumstances.
> >
> > Since the fscrypt d_ops are set later on, we must set all d_ops there,
> > since we cannot adjust those later on. This should not result in any
> > change in behavior.
> >
> > Signed-off-by: Daniel Rosenberg <[email protected]>
>
> Acked-by: Theodore Ts'o <[email protected]>
Hi Ted/Richard,
I'd like to pick this patch series in f2fs/dev for -next, so please let me know
if you have any concern.
Thanks,
On Tue, Nov 17, 2020 at 09:04:11AM -0800, Jaegeuk Kim wrote:
>
> I'd like to pick this patch series in f2fs/dev for -next, so please let me know
> if you have any concern.
No concern for me as far as ext4 is concerned, thanks!
- Ted
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 <[email protected]>
> and Jaegeuk Kim <[email protected]>.
>
> Co-developed-by: Eric Biggers <[email protected]>
> Signed-off-by: Eric Biggers <[email protected]>
> Signed-off-by: Daniel Rosenberg <[email protected]>
> ---
> 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
On Tue, Nov 17, 2020 at 04:03:12AM +0000, Daniel Rosenberg wrote:
> I've included one ext4 patch from the previous set since it isn't in the f2fs
> branch, but is needed for the fscrypt changes.
Note that this is no longer the case, as this ext4 patch was merged in 5.10
(commit f8f4acb6cded: "ext4: use generic casefolding support").
- Eric
On Tue, Nov 17, 2020 at 10:22:28PM -0800, Daniel Rosenberg wrote:
> > > @@ -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
> The 0 case is important, since that reflects that the name was not found.
I meant doing the following:
if (res < 0)
return ERR_PTR(res);
if (res)
goto found;
It doesn't really matter, but usually kernel code doesn't use 'else' after an
early return.
- Eric