f2fs: avoid deadlock on init_inode_metadata

Previously, init_inode_metadata does not hold any parent directory's inode
page. So, f2fs_init_acl can grab its parent inode page without any problem.
But, when we use inline_dentry, that page is grabbed during f2fs_add_link,
so that we can fall into deadlock condition like below.

INFO: task mknod:11006 blocked for more than 120 seconds.
      Tainted: G           OE  3.17.0-rc1+ #13
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mknod           D ffff88003fc94580     0 11006  11004 0x00000000
 ffff880007717b10 0000000000000002 ffff88003c323220 ffff880007717fd8
 0000000000014580 0000000000014580 ffff88003daecb30 ffff88003c323220
 ffff88003fc94e80 ffff88003ffbb4e8 ffff880007717ba0 0000000000000002
Call Trace:
 [<ffffffff8173dc40>] ? bit_wait+0x50/0x50
 [<ffffffff8173d4cd>] io_schedule+0x9d/0x130
 [<ffffffff8173dc6c>] bit_wait_io+0x2c/0x50
 [<ffffffff8173da3b>] __wait_on_bit_lock+0x4b/0xb0
 [<ffffffff811640a7>] __lock_page+0x67/0x70
 [<ffffffff810acf50>] ? autoremove_wake_function+0x40/0x40
 [<ffffffff811652cc>] pagecache_get_page+0x14c/0x1e0
 [<ffffffffa029afa9>] get_node_page+0x59/0x130 [f2fs]
 [<ffffffffa02a63ad>] read_all_xattrs+0x24d/0x430 [f2fs]
 [<ffffffffa02a6ca2>] f2fs_getxattr+0x52/0xe0 [f2fs]
 [<ffffffffa02a7481>] f2fs_get_acl+0x41/0x2d0 [f2fs]
 [<ffffffff8122d847>] get_acl+0x47/0x70
 [<ffffffff8122db5a>] posix_acl_create+0x5a/0x150
 [<ffffffffa02a7759>] f2fs_init_acl+0x29/0xcb [f2fs]
 [<ffffffffa0286a8d>] init_inode_metadata+0x5d/0x340 [f2fs]
 [<ffffffffa029253a>] f2fs_add_inline_entry+0x12a/0x2e0 [f2fs]
 [<ffffffffa0286ea5>] __f2fs_add_link+0x45/0x4a0 [f2fs]
 [<ffffffffa028b5b6>] ? f2fs_new_inode+0x146/0x220 [f2fs]
 [<ffffffffa028b816>] f2fs_mknod+0x86/0xf0 [f2fs]
 [<ffffffff811e3ec1>] vfs_mknod+0xe1/0x160
 [<ffffffff811e4b26>] SyS_mknod+0x1f6/0x200
 [<ffffffff81741d7f>] tracesys+0xe1/0xe6

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim
2014-10-13 19:42:53 -07:00
parent 59a0615540
commit bce8d11207
7 changed files with 157 additions and 22 deletions

View File

@@ -162,7 +162,8 @@ fail:
return ERR_PTR(-EINVAL);
}
struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
struct page *dpage)
{
int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
void *value = NULL;
@@ -172,12 +173,13 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
if (type == ACL_TYPE_ACCESS)
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
if (retval > 0) {
value = kmalloc(retval, GFP_F2FS_ZERO);
if (!value)
return ERR_PTR(-ENOMEM);
retval = f2fs_getxattr(inode, name_index, "", value, retval);
retval = f2fs_getxattr(inode, name_index, "", value,
retval, dpage);
}
if (retval > 0)
@@ -194,6 +196,11 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
return acl;
}
struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
{
return __f2fs_get_acl(inode, type, NULL);
}
static int __f2fs_set_acl(struct inode *inode, int type,
struct posix_acl *acl, struct page *ipage)
{
@@ -249,12 +256,137 @@ int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
return __f2fs_set_acl(inode, type, acl, NULL);
}
int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage)
/*
* Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
* are copied from posix_acl.c
*/
static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
gfp_t flags)
{
struct posix_acl *default_acl, *acl;
struct posix_acl *clone = NULL;
if (acl) {
int size = sizeof(struct posix_acl) + acl->a_count *
sizeof(struct posix_acl_entry);
clone = kmemdup(acl, size, flags);
if (clone)
atomic_set(&clone->a_refcount, 1);
}
return clone;
}
static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
{
struct posix_acl_entry *pa, *pe;
struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
umode_t mode = *mode_p;
int not_equiv = 0;
/* assert(atomic_read(acl->a_refcount) == 1); */
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch(pa->e_tag) {
case ACL_USER_OBJ:
pa->e_perm &= (mode >> 6) | ~S_IRWXO;
mode &= (pa->e_perm << 6) | ~S_IRWXU;
break;
case ACL_USER:
case ACL_GROUP:
not_equiv = 1;
break;
case ACL_GROUP_OBJ:
group_obj = pa;
break;
case ACL_OTHER:
pa->e_perm &= mode | ~S_IRWXO;
mode &= pa->e_perm | ~S_IRWXO;
break;
case ACL_MASK:
mask_obj = pa;
not_equiv = 1;
break;
default:
return -EIO;
}
}
if (mask_obj) {
mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
} else {
if (!group_obj)
return -EIO;
group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
}
*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
return not_equiv;
}
static int f2fs_acl_create(struct inode *dir, umode_t *mode,
struct posix_acl **default_acl, struct posix_acl **acl,
struct page *dpage)
{
struct posix_acl *p;
int ret;
if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
goto no_acl;
p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
if (IS_ERR(p)) {
if (p == ERR_PTR(-EOPNOTSUPP))
goto apply_umask;
return PTR_ERR(p);
}
if (!p)
goto apply_umask;
*acl = f2fs_acl_clone(p, GFP_NOFS);
if (!*acl)
return -ENOMEM;
ret = f2fs_acl_create_masq(*acl, mode);
if (ret < 0) {
posix_acl_release(*acl);
return -ENOMEM;
}
if (ret == 0) {
posix_acl_release(*acl);
*acl = NULL;
}
if (!S_ISDIR(*mode)) {
posix_acl_release(p);
*default_acl = NULL;
} else {
*default_acl = p;
}
return 0;
apply_umask:
*mode &= ~current_umask();
no_acl:
*default_acl = NULL;
*acl = NULL;
return 0;
}
int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
struct page *dpage)
{
struct posix_acl *default_acl = NULL, *acl = NULL;
int error = 0;
error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
if (error)
return error;