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a583c02664
linux/fs/f2fs/namei.c
Chao Yu b73e52824c f2fs: reposition unlock_new_inode to prevent accessing invalid inode 
As the race condition on the inode cache, following scenario can appear:
[Thread a]				[Thread b]
					->f2fs_mkdir
					  ->f2fs_add_link
					    ->__f2fs_add_link
					      ->init_inode_metadata failed here
->gc_thread_func
  ->f2fs_gc
    ->do_garbage_collect
      ->gc_data_segment
        ->f2fs_iget
          ->iget_locked
            ->wait_on_inode
					  ->unlock_new_inode
        ->move_data_page
					  ->make_bad_inode
					  ->iput

When we fail in create/symlink/mkdir/mknod/tmpfile, the new allocated inode
should be set as bad to avoid being accessed by other thread. But in above
scenario, it allows f2fs to access the invalid inode before this inode was set
as bad.
This patch fix the potential problem, and this issue was found by code review.

change log from v1:
 o Add condition judgment in gc_data_segment() suggested by Changman Lee.
 o use iget_failed to simplify code.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-09-02 00:22:24 -07:00

737 lines
17 KiB
C
Raw Blame History

/*
* fs/f2fs/namei.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/dcache.h>
#include "f2fs.h"
#include "node.h"
#include "xattr.h"
#include "acl.h"
#include <trace/events/f2fs.h>
static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
nid_t ino;
struct inode *inode;
bool nid_free = false;
int err;
inode = new_inode(dir->i_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
f2fs_lock_op(sbi);
if (!alloc_nid(sbi, &ino)) {
f2fs_unlock_op(sbi);
err = -ENOSPC;
goto fail;
}
f2fs_unlock_op(sbi);
inode_init_owner(inode, dir, mode);
inode->i_ino = ino;
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_generation = sbi->s_next_generation++;
err = insert_inode_locked(inode);
if (err) {
err = -EINVAL;
nid_free = true;
goto out;
}
trace_f2fs_new_inode(inode, 0);
mark_inode_dirty(inode);
return inode;
out:
clear_nlink(inode);
unlock_new_inode(inode);
fail:
trace_f2fs_new_inode(inode, err);
make_bad_inode(inode);
iput(inode);
if (nid_free)
alloc_nid_failed(sbi, ino);
return ERR_PTR(err);
}
static int is_multimedia_file(const unsigned char *s, const char *sub)
{
size_t slen = strlen(s);
size_t sublen = strlen(sub);
if (sublen > slen)
return 0;
return !strncasecmp(s + slen - sublen, sub, sublen);
}
/*
* Set multimedia files as cold files for hot/cold data separation
*/
static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
const unsigned char *name)
{
int i;
__u8 (*extlist)[8] = sbi->raw_super->extension_list;
int count = le32_to_cpu(sbi->raw_super->extension_count);
for (i = 0; i < count; i++) {
if (is_multimedia_file(name, extlist[i])) {
file_set_cold(inode);
break;
}
}
}
static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode;
nid_t ino = 0;
int err;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
set_cold_files(sbi, inode, dentry->d_name.name);
inode->i_op = &f2fs_file_inode_operations;
inode->i_fop = &f2fs_file_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
ino = inode->i_ino;
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
alloc_nid_done(sbi, ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return 0;
out:
clear_nlink(inode);
iget_failed(inode);
alloc_nid_failed(sbi, ino);
return err;
}
static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
int err;
f2fs_balance_fs(sbi);
inode->i_ctime = CURRENT_TIME;
ihold(inode);
set_inode_flag(F2FS_I(inode), FI_INC_LINK);
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
d_instantiate(dentry, inode);
return 0;
out:
clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
iput(inode);
return err;
}
struct dentry *f2fs_get_parent(struct dentry *child)
{
struct qstr dotdot = QSTR_INIT("..", 2);
unsigned long ino = f2fs_inode_by_name(child->d_inode, &dotdot);
if (!ino)
return ERR_PTR(-ENOENT);
return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
}
static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = NULL;
struct f2fs_dir_entry *de;
struct page *page;
if (dentry->d_name.len > F2FS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
de = f2fs_find_entry(dir, &dentry->d_name, &page);
if (de) {
nid_t ino = le32_to_cpu(de->ino);
kunmap(page);
f2fs_put_page(page, 0);
inode = f2fs_iget(dir->i_sb, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
stat_inc_inline_inode(inode);
}
return d_splice_alias(inode, dentry);
}
static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode = dentry->d_inode;
struct f2fs_dir_entry *de;
struct page *page;
int err = -ENOENT;
trace_f2fs_unlink_enter(dir, dentry);
f2fs_balance_fs(sbi);
de = f2fs_find_entry(dir, &dentry->d_name, &page);
if (!de)
goto fail;
f2fs_lock_op(sbi);
err = acquire_orphan_inode(sbi);
if (err) {
f2fs_unlock_op(sbi);
kunmap(page);
f2fs_put_page(page, 0);
goto fail;
}
f2fs_delete_entry(de, page, inode);
f2fs_unlock_op(sbi);
/* In order to evict this inode, we set it dirty */
mark_inode_dirty(inode);
fail:
trace_f2fs_unlink_exit(inode, err);
return err;
}
static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode;
size_t symlen = strlen(symname) + 1;
int err;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &f2fs_symlink_inode_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
err = page_symlink(inode, symname, symlen);
alloc_nid_done(sbi, inode->i_ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return err;
out:
clear_nlink(inode);
iget_failed(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode;
int err;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, S_IFDIR | mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &f2fs_dir_inode_operations;
inode->i_fop = &f2fs_dir_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
set_inode_flag(F2FS_I(inode), FI_INC_LINK);
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out_fail;
alloc_nid_done(sbi, inode->i_ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return 0;
out_fail:
clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
clear_nlink(inode);
iget_failed(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
if (f2fs_empty_dir(inode))
return f2fs_unlink(dir, dentry);
return -ENOTEMPTY;
}
static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode;
int err = 0;
if (!new_valid_dev(rdev))
return -EINVAL;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
init_special_inode(inode, inode->i_mode, rdev);
inode->i_op = &f2fs_special_inode_operations;
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
alloc_nid_done(sbi, inode->i_ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return 0;
out:
clear_nlink(inode);
iget_failed(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct f2fs_sb_info *sbi = F2FS_SB(old_dir->i_sb);
struct inode *old_inode = old_dentry->d_inode;
struct inode *new_inode = new_dentry->d_inode;
struct page *old_dir_page;
struct page *old_page, *new_page;
struct f2fs_dir_entry *old_dir_entry = NULL;
struct f2fs_dir_entry *old_entry;
struct f2fs_dir_entry *new_entry;
int err = -ENOENT;
f2fs_balance_fs(sbi);
old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
if (!old_entry)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
if (!old_dir_entry)
goto out_old;
}
if (new_inode) {
err = -ENOTEMPTY;
if (old_dir_entry && !f2fs_empty_dir(new_inode))
goto out_dir;
err = -ENOENT;
new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
&new_page);
if (!new_entry)
goto out_dir;
f2fs_lock_op(sbi);
err = acquire_orphan_inode(sbi);
if (err)
goto put_out_dir;
if (update_dent_inode(old_inode, &new_dentry->d_name)) {
release_orphan_inode(sbi);
goto put_out_dir;
}
f2fs_set_link(new_dir, new_entry, new_page, old_inode);
new_inode->i_ctime = CURRENT_TIME;
down_write(&F2FS_I(new_inode)->i_sem);
if (old_dir_entry)
drop_nlink(new_inode);
drop_nlink(new_inode);
up_write(&F2FS_I(new_inode)->i_sem);
mark_inode_dirty(new_inode);
if (!new_inode->i_nlink)
add_orphan_inode(sbi, new_inode->i_ino);
else
release_orphan_inode(sbi);
update_inode_page(old_inode);
update_inode_page(new_inode);
} else {
f2fs_lock_op(sbi);
err = f2fs_add_link(new_dentry, old_inode);
if (err) {
f2fs_unlock_op(sbi);
goto out_dir;
}
if (old_dir_entry) {
inc_nlink(new_dir);
update_inode_page(new_dir);
}
}
down_write(&F2FS_I(old_inode)->i_sem);
file_lost_pino(old_inode);
up_write(&F2FS_I(old_inode)->i_sem);
old_inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(old_inode);
f2fs_delete_entry(old_entry, old_page, NULL);
if (old_dir_entry) {
if (old_dir != new_dir) {
f2fs_set_link(old_inode, old_dir_entry,
old_dir_page, new_dir);
update_inode_page(old_inode);
} else {
kunmap(old_dir_page);
f2fs_put_page(old_dir_page, 0);
}
drop_nlink(old_dir);
mark_inode_dirty(old_dir);
update_inode_page(old_dir);
}
f2fs_unlock_op(sbi);
return 0;
put_out_dir:
f2fs_unlock_op(sbi);
kunmap(new_page);
f2fs_put_page(new_page, 0);
out_dir:
if (old_dir_entry) {
kunmap(old_dir_page);
f2fs_put_page(old_dir_page, 0);
}
out_old:
kunmap(old_page);
f2fs_put_page(old_page, 0);
out:
return err;
}
static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct super_block *sb = old_dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *old_inode = old_dentry->d_inode;
struct inode *new_inode = new_dentry->d_inode;
struct page *old_dir_page, *new_dir_page;
struct page *old_page, *new_page;
struct f2fs_dir_entry *old_dir_entry = NULL, *new_dir_entry = NULL;
struct f2fs_dir_entry *old_entry, *new_entry;
int old_nlink = 0, new_nlink = 0;
int err = -ENOENT;
f2fs_balance_fs(sbi);
old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
if (!old_entry)
goto out;
new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
if (!new_entry)
goto out_old;
/* prepare for updating ".." directory entry info later */
if (old_dir != new_dir) {
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
old_dir_entry = f2fs_parent_dir(old_inode,
&old_dir_page);
if (!old_dir_entry)
goto out_new;
}
if (S_ISDIR(new_inode->i_mode)) {
err = -EIO;
new_dir_entry = f2fs_parent_dir(new_inode,
&new_dir_page);
if (!new_dir_entry)
goto out_old_dir;
}
}
/*
* If cross rename between file and directory those are not
* in the same directory, we will inc nlink of file's parent
* later, so we should check upper boundary of its nlink.
*/
if ((!old_dir_entry || !new_dir_entry) &&
old_dir_entry != new_dir_entry) {
old_nlink = old_dir_entry ? -1 : 1;
new_nlink = -old_nlink;
err = -EMLINK;
if ((old_nlink > 0 && old_inode->i_nlink >= F2FS_LINK_MAX) ||
(new_nlink > 0 && new_inode->i_nlink >= F2FS_LINK_MAX))
goto out_new_dir;
}
f2fs_lock_op(sbi);
err = update_dent_inode(old_inode, &new_dentry->d_name);
if (err)
goto out_unlock;
err = update_dent_inode(new_inode, &old_dentry->d_name);
if (err)
goto out_undo;
/* update ".." directory entry info of old dentry */
if (old_dir_entry)
f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);
/* update ".." directory entry info of new dentry */
if (new_dir_entry)
f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);
/* update directory entry info of old dir inode */
f2fs_set_link(old_dir, old_entry, old_page, new_inode);
down_write(&F2FS_I(old_inode)->i_sem);
file_lost_pino(old_inode);
up_write(&F2FS_I(old_inode)->i_sem);
update_inode_page(old_inode);
old_dir->i_ctime = CURRENT_TIME;
if (old_nlink) {
down_write(&F2FS_I(old_dir)->i_sem);
if (old_nlink < 0)
drop_nlink(old_dir);
else
inc_nlink(old_dir);
up_write(&F2FS_I(old_dir)->i_sem);
}
mark_inode_dirty(old_dir);
update_inode_page(old_dir);
/* update directory entry info of new dir inode */
f2fs_set_link(new_dir, new_entry, new_page, old_inode);
down_write(&F2FS_I(new_inode)->i_sem);
file_lost_pino(new_inode);
up_write(&F2FS_I(new_inode)->i_sem);
update_inode_page(new_inode);
new_dir->i_ctime = CURRENT_TIME;
if (new_nlink) {
down_write(&F2FS_I(new_dir)->i_sem);
if (new_nlink < 0)
drop_nlink(new_dir);
else
inc_nlink(new_dir);
up_write(&F2FS_I(new_dir)->i_sem);
}
mark_inode_dirty(new_dir);
update_inode_page(new_dir);
f2fs_unlock_op(sbi);
return 0;
out_undo:
/* Still we may fail to recover name info of f2fs_inode here */
update_dent_inode(old_inode, &old_dentry->d_name);
out_unlock:
f2fs_unlock_op(sbi);
out_new_dir:
if (new_dir_entry) {
kunmap(new_dir_page);
f2fs_put_page(new_dir_page, 0);
}
out_old_dir:
if (old_dir_entry) {
kunmap(old_dir_page);
f2fs_put_page(old_dir_page, 0);
}
out_new:
kunmap(new_page);
f2fs_put_page(new_page, 0);
out_old:
kunmap(old_page);
f2fs_put_page(old_page, 0);
out:
return err;
}
static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
return -EINVAL;
if (flags & RENAME_EXCHANGE) {
return f2fs_cross_rename(old_dir, old_dentry,
new_dir, new_dentry);
}
/*
* VFS has already handled the new dentry existence case,
* here, we just deal with "RENAME_NOREPLACE" as regular rename.
*/
return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry);
}
static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode;
int err;
inode = f2fs_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &f2fs_file_inode_operations;
inode->i_fop = &f2fs_file_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
f2fs_lock_op(sbi);
err = acquire_orphan_inode(sbi);
if (err)
goto out;
err = f2fs_do_tmpfile(inode, dir);
if (err)
goto release_out;
/*
* add this non-linked tmpfile to orphan list, in this way we could
* remove all unused data of tmpfile after abnormal power-off.
*/
add_orphan_inode(sbi, inode->i_ino);
f2fs_unlock_op(sbi);
alloc_nid_done(sbi, inode->i_ino);
d_tmpfile(dentry, inode);
unlock_new_inode(inode);
return 0;
release_out:
release_orphan_inode(sbi);
out:
f2fs_unlock_op(sbi);
clear_nlink(inode);
iget_failed(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
const struct inode_operations f2fs_dir_inode_operations = {
.create = f2fs_create,
.lookup = f2fs_lookup,
.link = f2fs_link,
.unlink = f2fs_unlink,
.symlink = f2fs_symlink,
.mkdir = f2fs_mkdir,
.rmdir = f2fs_rmdir,
.mknod = f2fs_mknod,
.rename2 = f2fs_rename2,
.tmpfile = f2fs_tmpfile,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
.get_acl = f2fs_get_acl,
.set_acl = f2fs_set_acl,
#ifdef CONFIG_F2FS_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = f2fs_listxattr,
.removexattr = generic_removexattr,
#endif
};
const struct inode_operations f2fs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
#ifdef CONFIG_F2FS_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = f2fs_listxattr,
.removexattr = generic_removexattr,
#endif
};
const struct inode_operations f2fs_special_inode_operations = {
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
.get_acl = f2fs_get_acl,
.set_acl = f2fs_set_acl,
#ifdef CONFIG_F2FS_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = f2fs_listxattr,
.removexattr = generic_removexattr,
#endif
};
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