[PATCH] f2fs crypto: avoid unneeded memory allocation when {en/de}crypting symlink
From: Chao Yu
Date: Mon Feb 15 2016 - 04:55:18 EST
This patch adopts f2fs with codes of ext4, it removes unneeded memory
allocation in creating/accessing path of symlink.
Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
---
fs/f2fs/crypto_fname.c | 21 +++++++++------
fs/f2fs/f2fs.h | 1 +
fs/f2fs/namei.c | 72 ++++++++++++++++++++++++--------------------------
3 files changed, 48 insertions(+), 46 deletions(-)
diff --git a/fs/f2fs/crypto_fname.c b/fs/f2fs/crypto_fname.c
index 73741fb..6dfdc97 100644
--- a/fs/f2fs/crypto_fname.c
+++ b/fs/f2fs/crypto_fname.c
@@ -257,6 +257,18 @@ u32 f2fs_fname_crypto_round_up(u32 size, u32 blksize)
return ((size + blksize - 1) / blksize) * blksize;
}
+unsigned f2fs_fname_encrypted_size(struct inode *inode, u32 ilen)
+{
+ struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info;
+ int padding = 32;
+
+ if (ci)
+ padding = 4 << (ci->ci_flags & F2FS_POLICY_FLAGS_PAD_MASK);
+ if (ilen < F2FS_CRYPTO_BLOCK_SIZE)
+ ilen = F2FS_CRYPTO_BLOCK_SIZE;
+ return f2fs_fname_crypto_round_up(ilen, padding);
+}
+
/**
* f2fs_fname_crypto_alloc_obuff() -
*
@@ -266,15 +278,8 @@ u32 f2fs_fname_crypto_round_up(u32 size, u32 blksize)
int f2fs_fname_crypto_alloc_buffer(struct inode *inode,
u32 ilen, struct f2fs_str *crypto_str)
{
- unsigned int olen;
- int padding = 32;
- struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info;
+ unsigned int olen = f2fs_fname_encrypted_size(inode, ilen);
- if (ci)
- padding = 4 << (ci->ci_flags & F2FS_POLICY_FLAGS_PAD_MASK);
- if (ilen < F2FS_CRYPTO_BLOCK_SIZE)
- ilen = F2FS_CRYPTO_BLOCK_SIZE;
- olen = f2fs_fname_crypto_round_up(ilen, padding);
crypto_str->len = olen;
if (olen < F2FS_FNAME_CRYPTO_DIGEST_SIZE * 2)
olen = F2FS_FNAME_CRYPTO_DIGEST_SIZE * 2;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c4c7bf1..fc302ea 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2225,6 +2225,7 @@ int _f2fs_get_encryption_info(struct inode *inode);
/* crypto_fname.c */
bool f2fs_valid_filenames_enc_mode(uint32_t);
u32 f2fs_fname_crypto_round_up(u32, u32);
+unsigned f2fs_fname_encrypted_size(struct inode *, u32);
int f2fs_fname_crypto_alloc_buffer(struct inode *, u32, struct f2fs_str *);
int f2fs_fname_disk_to_usr(struct inode *, f2fs_hash_t *,
const struct f2fs_str *, struct f2fs_str *);
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 6f944e5..fcc8c26 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -345,13 +345,23 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
struct inode *inode;
size_t len = strlen(symname);
- size_t p_len;
- char *p_str;
- struct f2fs_str disk_link = FSTR_INIT(NULL, 0);
+ struct f2fs_str disk_link = FSTR_INIT((char *)symname, len + 1);
struct f2fs_encrypted_symlink_data *sd = NULL;
int err;
- if (len > dir->i_sb->s_blocksize)
+ if (f2fs_encrypted_inode(dir)) {
+ err = f2fs_get_encryption_info(dir);
+ if (err)
+ return err;
+
+ if (!f2fs_encrypted_inode(dir))
+ return -EPERM;
+
+ disk_link.len = (f2fs_fname_encrypted_size(dir, len) +
+ sizeof(struct f2fs_encrypted_symlink_data));
+ }
+
+ if (disk_link.len > dir->i_sb->s_blocksize)
return -ENAMETOOLONG;
inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
@@ -374,42 +384,36 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
f2fs_unlock_op(sbi);
alloc_nid_done(sbi, inode->i_ino);
- if (f2fs_encrypted_inode(dir)) {
+ if (f2fs_encrypted_inode(inode)) {
struct qstr istr = QSTR_INIT(symname, len);
+ struct f2fs_str ostr;
- err = f2fs_get_encryption_info(inode);
- if (err)
+ sd = kzalloc(disk_link.len, GFP_NOFS);
+ if (!sd) {
+ err = -ENOMEM;
goto err_out;
+ }
- err = f2fs_fname_crypto_alloc_buffer(inode, len, &disk_link);
+ err = f2fs_get_encryption_info(inode);
if (err)
goto err_out;
- err = f2fs_fname_usr_to_disk(inode, &istr, &disk_link);
- if (err < 0)
- goto err_out;
-
- p_len = encrypted_symlink_data_len(disk_link.len) + 1;
-
- if (p_len > dir->i_sb->s_blocksize) {
- err = -ENAMETOOLONG;
+ if (!f2fs_encrypted_inode(inode)) {
+ err = -EPERM;
goto err_out;
}
- sd = kzalloc(p_len, GFP_NOFS);
- if (!sd) {
- err = -ENOMEM;
+ ostr.name = sd->encrypted_path;
+ ostr.len = disk_link.len;
+ err = f2fs_fname_usr_to_disk(inode, &istr, &ostr);
+ if (err < 0)
goto err_out;
- }
- memcpy(sd->encrypted_path, disk_link.name, disk_link.len);
- sd->len = cpu_to_le16(disk_link.len);
- p_str = (char *)sd;
- } else {
- p_len = len + 1;
- p_str = (char *)symname;
+
+ sd->len = cpu_to_le16(ostr.len);
+ disk_link.name = (char *)sd;
}
- err = page_symlink(inode, p_str, p_len);
+ err = page_symlink(inode, disk_link.name, disk_link.len);
err_out:
d_instantiate(dentry, inode);
@@ -425,7 +429,8 @@ err_out:
* performance regression.
*/
if (!err) {
- filemap_write_and_wait_range(inode->i_mapping, 0, p_len - 1);
+ filemap_write_and_wait_range(inode->i_mapping, 0,
+ disk_link.len - 1);
if (IS_DIRSYNC(dir))
f2fs_sync_fs(sbi->sb, 1);
@@ -434,7 +439,6 @@ err_out:
}
kfree(sd);
- f2fs_fname_crypto_free_buffer(&disk_link);
return err;
out:
handle_failed_inode(inode);
@@ -966,6 +970,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
/* Symlink is encrypted */
sd = (struct f2fs_encrypted_symlink_data *)caddr;
+ cstr.name = sd->encrypted_path;
cstr.len = le16_to_cpu(sd->len);
/* this is broken symlink case */
@@ -973,12 +978,6 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
res = -ENOENT;
goto errout;
}
- cstr.name = kmalloc(cstr.len, GFP_NOFS);
- if (!cstr.name) {
- res = -ENOMEM;
- goto errout;
- }
- memcpy(cstr.name, sd->encrypted_path, cstr.len);
/* this is broken symlink case */
if (unlikely(cstr.name[0] == 0)) {
@@ -1000,8 +999,6 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
if (res < 0)
goto errout;
- kfree(cstr.name);
-
paddr = pstr.name;
/* Null-terminate the name */
@@ -1011,7 +1008,6 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
set_delayed_call(done, kfree_link, paddr);
return paddr;
errout:
- kfree(cstr.name);
f2fs_fname_crypto_free_buffer(&pstr);
page_cache_release(cpage);
return ERR_PTR(res);
--
2.7.0