From 922ec355f86365388203672119b5bca346a45085 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 15 Feb 2016 17:54:26 +0800 Subject: [PATCH] f2fs crypto: avoid unneeded memory allocation when {en/de}crypting symlink This patch adopts f2fs with codes of ext4, it removes unneeded memory allocation in creating/accessing path of symlink. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- 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 73741fb65069..6dfdc978fe45 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 0d2b1ba9660e..f9c294eee0f1 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2226,6 +2226,7 @@ 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 6f944e5eb76e..fcc8c26c0fe8 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); -- 2.11.0