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>

diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 83b9b5a..6207455 100644 (file)
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -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 *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, *acl;
+       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;
 

diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
index e086465..997ca8e 100644 (file)
--- a/fs/f2fs/acl.h
+++ b/fs/f2fs/acl.h
@@ -38,14 +38,15 @@ struct f2fs_acl_header {
 
 extern struct posix_acl *f2fs_get_acl(struct inode *, int);
 extern int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
-extern int f2fs_init_acl(struct inode *, struct inode *, struct page *);
+extern int f2fs_init_acl(struct inode *, struct inode *, struct page *,
+                                                       struct page *);
 #else
 #define f2fs_check_acl NULL
 #define f2fs_get_acl   NULL
 #define f2fs_set_acl   NULL
 
 static inline int f2fs_init_acl(struct inode *inode, struct inode *dir,
-                                                       struct page *page)
+                               struct page *ipage, struct page *dpage)
 {
        return 0;
 }

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 35cb1b3..e5439dd 100644 (file)
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -363,8 +363,8 @@ static int make_empty_dir(struct inode *inode,
        return 0;
 }
 
-struct page *init_inode_metadata(struct inode *inode,
-               struct inode *dir, const struct qstr *name)
+struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
+                       const struct qstr *name, struct page *dpage)
 {
        struct page *page;
        int err;
@@ -380,7 +380,7 @@ struct page *init_inode_metadata(struct inode *inode,
                                goto error;
                }
 
-               err = f2fs_init_acl(inode, dir, page);
+               err = f2fs_init_acl(inode, dir, page, dpage);
                if (err)
                        goto put_error;
 
@@ -541,7 +541,7 @@ add_dentry:
        f2fs_wait_on_page_writeback(dentry_page, DATA);
 
        down_write(&F2FS_I(inode)->i_sem);
-       page = init_inode_metadata(inode, dir, name);
+       page = init_inode_metadata(inode, dir, name, NULL);
        if (IS_ERR(page)) {
                err = PTR_ERR(page);
                goto fail;
@@ -580,7 +580,7 @@ int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
        int err = 0;
 
        down_write(&F2FS_I(inode)->i_sem);
-       page = init_inode_metadata(inode, dir, NULL);
+       page = init_inode_metadata(inode, dir, NULL, NULL);
        if (IS_ERR(page)) {
                err = PTR_ERR(page);
                goto fail;

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 6aad6e0..d4dcd93 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1247,7 +1247,7 @@ void set_de_type(struct f2fs_dir_entry *, struct inode *);
 struct f2fs_dir_entry *find_target_dentry(struct qstr *, int *, const void *,
                        struct f2fs_dir_entry *, __u8 (*)[F2FS_SLOT_LEN]);
 struct page *init_inode_metadata(struct inode *, struct inode *,
-                                                       const struct qstr *);
+                       const struct qstr *, struct page *);
 void update_parent_metadata(struct inode *, struct inode *, unsigned int);
 int room_for_filename(const void *, int, int);
 void f2fs_drop_nlink(struct inode *, struct inode *, struct page *);

diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 175f38a..46c5542 100644 (file)
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -427,14 +427,14 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
                goto out;
        }
 
-       f2fs_wait_on_page_writeback(ipage, NODE);
-
        down_write(&F2FS_I(inode)->i_sem);
-       page = init_inode_metadata(inode, dir, name);
+       page = init_inode_metadata(inode, dir, name, ipage);
        if (IS_ERR(page)) {
                err = PTR_ERR(page);
                goto fail;
        }
+
+       f2fs_wait_on_page_writeback(ipage, NODE);
        de = &dentry_blk->dentry[bit_pos];
        de->hash_code = name_hash;
        de->name_len = cpu_to_le16(namelen);

diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index deca872..5072bf9 100644 (file)
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -83,7 +83,7 @@ static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
        }
        if (strcmp(name, "") == 0)
                return -EINVAL;
-       return f2fs_getxattr(dentry->d_inode, type, name, buffer, size);
+       return f2fs_getxattr(dentry->d_inode, type, name, buffer, size, NULL);
 }
 
 static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
@@ -398,7 +398,7 @@ static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
 }
 
 int f2fs_getxattr(struct inode *inode, int index, const char *name,
-               void *buffer, size_t buffer_size)
+               void *buffer, size_t buffer_size, struct page *ipage)
 {
        struct f2fs_xattr_entry *entry;
        void *base_addr;
@@ -412,7 +412,7 @@ int f2fs_getxattr(struct inode *inode, int index, const char *name,
        if (len > F2FS_NAME_LEN)
                return -ERANGE;
 
-       base_addr = read_all_xattrs(inode, NULL);
+       base_addr = read_all_xattrs(inode, ipage);
        if (!base_addr)
                return -ENOMEM;
 

diff --git a/fs/f2fs/xattr.h b/fs/f2fs/xattr.h
index 34ab7db..969d792 100644 (file)
--- a/fs/f2fs/xattr.h
+++ b/fs/f2fs/xattr.h
@@ -115,7 +115,8 @@ extern const struct xattr_handler *f2fs_xattr_handlers[];
 
 extern int f2fs_setxattr(struct inode *, int, const char *,
                                const void *, size_t, struct page *, int);
-extern int f2fs_getxattr(struct inode *, int, const char *, void *, size_t);
+extern int f2fs_getxattr(struct inode *, int, const char *, void *,
+                                               size_t, struct page *);
 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
 #else
 
@@ -126,7 +127,8 @@ static inline int f2fs_setxattr(struct inode *inode, int index,
        return -EOPNOTSUPP;
 }
 static inline int f2fs_getxattr(struct inode *inode, int index,
-               const char *name, void *buffer, size_t buffer_size)
+                       const char *name, void *buffer,
+                       size_t buffer_size, struct page *dpage)
 {
        return -EOPNOTSUPP;
 }