Btrfs: Add ACL support

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index ff0fcc7..b192659 100644 (file)
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -20,76 +20,302 @@
 #include <linux/string.h>
 #include <linux/xattr.h>
 #include <linux/posix_acl_xattr.h>
+#include <linux/posix_acl.h>
 #include <linux/sched.h>
+
 #include "ctree.h"
+#include "btrfs_inode.h"
 #include "xattr.h"
-#ifndef is_owner_or_cap
-#define is_owner_or_cap(inode) \
-       ((current->fsuid == (inode)->i_uid) || capable(CAP_FOWNER))
-#endif
+
+static void btrfs_update_cached_acl(struct inode *inode,
+                                   struct posix_acl **p_acl,
+                                   struct posix_acl *acl)
+{
+       spin_lock(&inode->i_lock);
+       if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
+               posix_acl_release(*p_acl);
+       *p_acl = posix_acl_dup(acl);
+       spin_unlock(&inode->i_lock);
+}
+
+static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+{
+       int size, name_index;
+       char *value = NULL;
+       struct posix_acl *acl = NULL, **p_acl;
+
+       switch (type) {
+       case ACL_TYPE_ACCESS:
+               name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS;
+               p_acl = &BTRFS_I(inode)->i_acl;
+               break;
+       case ACL_TYPE_DEFAULT:
+               name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+               p_acl = &BTRFS_I(inode)->i_default_acl;
+               break;
+       default:
+               return ERR_PTR(-EINVAL);
+       }
+
+       spin_lock(&inode->i_lock);
+       if (*p_acl != BTRFS_ACL_NOT_CACHED)
+               acl = posix_acl_dup(*p_acl);
+       spin_unlock(&inode->i_lock);
+
+       if (acl)
+               return acl;
+
+
+       size = btrfs_xattr_get(inode, name_index, "", NULL, 0);
+       if (size > 0) {
+               value = kzalloc(size, GFP_NOFS);
+               if (!value)
+                       return ERR_PTR(-ENOMEM);
+               size = btrfs_xattr_get(inode, name_index, "", value, size);
+               if (size > 0) {
+                       acl = posix_acl_from_xattr(value, size);
+                       btrfs_update_cached_acl(inode, p_acl, acl);
+               }
+               kfree(value);
+       } else if (size == -ENOENT) {
+               acl = NULL;
+               btrfs_update_cached_acl(inode, p_acl, acl);
+       }
+
+       return acl;
+}
+
+static int btrfs_xattr_get_acl(struct inode *inode, int type,
+                              void *value, size_t size)
+{
+       struct posix_acl *acl;
+       int ret = 0;
+
+       acl = btrfs_get_acl(inode, type);
+
+       if (IS_ERR(acl))
+               return PTR_ERR(acl);
+       if (acl == NULL)
+               return -ENODATA;
+       ret = posix_acl_to_xattr(acl, value, size);
+       posix_acl_release(acl);
+
+       return ret;
+}
+
+/*
+ * Needs to be called with fs_mutex held
+ */
+static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+       int ret, name_index = 0, size = 0;
+       struct posix_acl **p_acl;
+       char *value = NULL;
+       mode_t mode;
+
+       if (acl) {
+               ret = posix_acl_valid(acl);
+               if (ret < 0)
+                       return ret;
+               ret = 0;
+       }
+
+       switch (type) {
+       case ACL_TYPE_ACCESS:
+               mode = inode->i_mode;
+               ret = posix_acl_equiv_mode(acl, &mode);
+               if (ret < 0)
+                       return ret;
+               ret = 0;
+               inode->i_mode = mode;
+               name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS;
+               p_acl = &BTRFS_I(inode)->i_acl;
+               break;
+       case ACL_TYPE_DEFAULT:
+               if (!S_ISDIR(inode->i_mode))
+                       return acl ? -EINVAL : 0;
+               name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+               p_acl = &BTRFS_I(inode)->i_default_acl;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (acl) {
+               size = posix_acl_xattr_size(acl->a_count);
+               value = kmalloc(size, GFP_NOFS);
+               if (!value) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
+
+               ret = posix_acl_to_xattr(acl, value, size);
+               if (ret < 0)
+                       goto out;
+       }
+
+       ret = btrfs_xattr_set(inode, name_index, "", value, size, 0);
+
+out:
+       if (value)
+               kfree(value);
+
+       if (!ret)
+               btrfs_update_cached_acl(inode, p_acl, acl);
+
+       return ret;
+}
 
 static int btrfs_xattr_set_acl(struct inode *inode, int type,
                               const void *value, size_t size)
 {
        int ret = 0;
-       struct posix_acl *acl;
+       struct posix_acl *acl = NULL;
 
-       if (!is_owner_or_cap(inode))
-               return -EPERM;
        if (value) {
                acl = posix_acl_from_xattr(value, size);
                if (acl == NULL) {
                        value = NULL;
                        size = 0;
                } else if (IS_ERR(acl)) {
-                       ret = PTR_ERR(acl);
-               } else {
-                       ret = posix_acl_valid(acl);
-                       posix_acl_release(acl);
+                       return PTR_ERR(acl);
                }
-               if (ret)
-                       return ret;
        }
-       return btrfs_xattr_set(inode, type, "", value, size, 0);
-}
 
-static int btrfs_xattr_get_acl(struct inode *inode, int type,
-                              void *value, size_t size)
-{
-       return btrfs_xattr_get(inode, type, "", value, size);
+       ret = btrfs_set_acl(inode, acl, type);
+
+       posix_acl_release(acl);
+
+       return ret;
 }
+
+
 static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
                                      void *value, size_t size)
 {
-       if (*name != '\0')
-              return -EINVAL;
-       return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
-                                  value, size);
+       return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
 }
+
 static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
                                      const void *value, size_t size, int flags)
 {
-       if (*name != '\0')
-              return -EINVAL;
-       return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
-                                  value, size);
+       return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
 }
+
 static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
                                       void *value, size_t size)
 {
-       if (*name != '\0')
-              return -EINVAL;
-       return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
-                                  value, size);
+       return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
 }
+
 static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
                                       const void *value, size_t size, int flags)
 {
-       if (*name != '\0')
-              return -EINVAL;
-       return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
-                                  value, size);
+       return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+       struct posix_acl *acl;
+       int error = -EAGAIN;
+
+       acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+
+       if (IS_ERR(acl))
+               return PTR_ERR(acl);
+       if (acl) {
+               error = posix_acl_permission(inode, acl, mask);
+               posix_acl_release(acl);
+       }
+
+       return error;
+}
+
+/*
+ * btrfs_init_acl is already generally called under fs_mutex, so the locking
+ * stuff has been fixed to work with that.  If the locking stuff changes, we
+ * need to re-evaluate the acl locking stuff.
+ */
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+       struct posix_acl *acl = NULL;
+       int ret = 0;
+
+       /* this happens with subvols */
+       if (!dir)
+               return 0;
+
+       if (!S_ISLNK(inode->i_mode)) {
+               if (IS_POSIXACL(dir)) {
+                       acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
+                       if (IS_ERR(acl))
+                               return PTR_ERR(acl);
+               }
+
+               if (!acl)
+                       inode->i_mode &= ~current->fs->umask;
+       }
+
+       if (IS_POSIXACL(dir) && acl) {
+               struct posix_acl *clone;
+               mode_t mode;
+
+               if (S_ISDIR(inode->i_mode)) {
+                       ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
+                       if (ret)
+                               goto failed;
+               }
+               clone = posix_acl_clone(acl, GFP_NOFS);
+               ret = -ENOMEM;
+               if (!clone)
+                       goto failed;
+
+               mode = inode->i_mode;
+               ret = posix_acl_create_masq(clone, &mode);
+               if (ret >= 0) {
+                       inode->i_mode = mode;
+                       if (ret > 0) {
+                               /* we need an acl */
+                               ret = btrfs_set_acl(inode, clone,
+                                                   ACL_TYPE_ACCESS);
+                       }
+               }
+       }
+failed:
+       posix_acl_release(acl);
+
+       return ret;
+}
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+       struct posix_acl *acl, *clone;
+       int ret = 0;
+
+       if (S_ISLNK(inode->i_mode))
+               return -EOPNOTSUPP;
+
+       if (!IS_POSIXACL(inode))
+               return 0;
+
+       acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+       if (IS_ERR(acl) || !acl)
+               return PTR_ERR(acl);
+
+       clone = posix_acl_clone(acl, GFP_KERNEL);
+       posix_acl_release(acl);
+       if (!clone)
+               return -ENOMEM;
+
+       ret = posix_acl_chmod_masq(clone, inode->i_mode);
+       if (!ret)
+               ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
+
+       posix_acl_release(clone);
+
+       return ret;
 }
+
 struct xattr_handler btrfs_xattr_acl_default_handler = {
        .prefix = POSIX_ACL_XATTR_DEFAULT,
        .list   = btrfs_xattr_generic_list,

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index b7bd60e..9f2a4ef 100644 (file)
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -36,6 +36,9 @@ struct btrfs_inode {
        struct inode vfs_inode;
        struct btrfs_ordered_inode_tree ordered_tree;
 
+       struct posix_acl *i_acl;
+       struct posix_acl *i_default_acl;
+
        /*
         * transid of the trans_handle that last modified this inode
         */

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 53d315b..f87d726 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -42,6 +42,8 @@ struct btrfs_ordered_sum;
 
 #define BTRFS_MAGIC "_B5RfS_M"
 
+#define BTRFS_ACL_NOT_CACHED    ((void *)-1)
+
 #ifdef CONFIG_LOCKDEP
 # define BTRFS_MAX_LEVEL 7
 #else
@@ -1694,4 +1696,9 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
 u64 btrfs_parse_size(char *str);
 int btrfs_parse_options(struct btrfs_root *root, char *options);
 int btrfs_sync_fs(struct super_block *sb, int wait);
+
+/* acl.c */
+int btrfs_check_acl(struct inode *inode, int mask);
+int btrfs_init_acl(struct inode *inode, struct inode *dir);
+int btrfs_acl_chmod(struct inode *inode);
 #endif

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8d371d6..2d88535 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -36,6 +36,7 @@
 #include <linux/bit_spinlock.h>
 #include <linux/version.h>
 #include <linux/xattr.h>
+#include <linux/posix_acl.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1478,6 +1479,9 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
        }
 out:
        err = inode_setattr(inode, attr);
+
+       if (!err && ((attr->ia_valid & ATTR_MODE)))
+               err = btrfs_acl_chmod(inode);
 fail:
        return err;
 }
@@ -2184,6 +2188,12 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
        if (IS_ERR(inode))
                goto out_unlock;
 
+       err = btrfs_init_acl(inode, dir);
+       if (err) {
+               drop_inode = 1;
+               goto out_unlock;
+       }
+
        btrfs_set_trans_block_group(trans, inode);
        err = btrfs_add_nondir(trans, dentry, inode, 0);
        if (err)
@@ -2239,6 +2249,12 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
        if (IS_ERR(inode))
                goto out_unlock;
 
+       err = btrfs_init_acl(inode, dir);
+       if (err) {
+               drop_inode = 1;
+               goto out_unlock;
+       }
+
        btrfs_set_trans_block_group(trans, inode);
        err = btrfs_add_nondir(trans, dentry, inode, 0);
        if (err)
@@ -2366,6 +2382,11 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
        }
 
        drop_on_err = 1;
+
+       err = btrfs_init_acl(inode, dir);
+       if (err)
+               goto out_fail;
+
        inode->i_op = &btrfs_dir_inode_operations;
        inode->i_fop = &btrfs_dir_file_operations;
        btrfs_set_trans_block_group(trans, inode);
@@ -3023,6 +3044,8 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
                return NULL;
        ei->last_trans = 0;
        btrfs_ordered_inode_tree_init(&ei->ordered_tree);
+       ei->i_acl = BTRFS_ACL_NOT_CACHED;
+       ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
        return &ei->vfs_inode;
 }
 
@@ -3032,6 +3055,13 @@ void btrfs_destroy_inode(struct inode *inode)
        WARN_ON(!list_empty(&inode->i_dentry));
        WARN_ON(inode->i_data.nrpages);
 
+       if (BTRFS_I(inode)->i_acl &&
+           BTRFS_I(inode)->i_acl != BTRFS_ACL_NOT_CACHED)
+               posix_acl_release(BTRFS_I(inode)->i_acl);
+       if (BTRFS_I(inode)->i_default_acl &&
+           BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
+               posix_acl_release(BTRFS_I(inode)->i_default_acl);
+
        while(1) {
                ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
                if (!ordered)
@@ -3230,6 +3260,12 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
        if (IS_ERR(inode))
                goto out_unlock;
 
+       err = btrfs_init_acl(inode, dir);
+       if (err) {
+               drop_inode = 1;
+               goto out_unlock;
+       }
+
        btrfs_set_trans_block_group(trans, inode);
        err = btrfs_add_nondir(trans, dentry, inode, 0);
        if (err)
@@ -3310,7 +3346,7 @@ static int btrfs_permission(struct inode *inode, int mask,
 {
        if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
                return -EACCES;
-       return generic_permission(inode, mask, NULL);
+       return generic_permission(inode, mask, btrfs_check_acl);
 }
 
 static struct inode_operations btrfs_dir_inode_operations = {
@@ -3392,6 +3428,10 @@ static struct inode_operations btrfs_special_inode_operations = {
        .getattr        = btrfs_getattr,
        .setattr        = btrfs_setattr,
        .permission     = btrfs_permission,
+       .setxattr       = generic_setxattr,
+       .getxattr       = generic_getxattr,
+       .listxattr      = btrfs_listxattr,
+       .removexattr    = generic_removexattr,
 };
 static struct inode_operations btrfs_symlink_inode_operations = {
        .readlink       = generic_readlink,

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4cb6aac..a6a418b 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -68,7 +68,7 @@ static void btrfs_put_super (struct super_block * sb)
 enum {
        Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
        Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
-       Opt_ssd, Opt_thread_pool, Opt_err,
+       Opt_ssd, Opt_thread_pool, Opt_noacl,  Opt_err,
 };
 
 static match_table_t tokens = {
@@ -83,7 +83,8 @@ static match_table_t tokens = {
        {Opt_alloc_start, "alloc_start=%s"},
        {Opt_thread_pool, "thread_pool=%d"},
        {Opt_ssd, "ssd"},
-       {Opt_err, NULL}
+       {Opt_noacl, "noacl"},
+       {Opt_err, NULL},
 };
 
 u64 btrfs_parse_size(char *str)
@@ -215,6 +216,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                        info->alloc_start);
                        }
                        break;
+               case Opt_noacl:
+                       root->fs_info->sb->s_flags &= ~MS_POSIXACL;
+                       break;
                default:
                        break;
                }
@@ -301,6 +305,7 @@ static int btrfs_fill_super(struct super_block * sb,
        sb->s_op = &btrfs_super_ops;
        sb->s_xattr = btrfs_xattr_handlers;
        sb->s_time_gran = 1;
+       sb->s_flags |= MS_POSIXACL;
 
        tree_root = open_ctree(sb, fs_devices, (char *)data);
 

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 6730b59..121c955 100644 (file)
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -26,25 +26,27 @@
 #include "transaction.h"
 #include "xattr.h"
 #include "disk-io.h"
+
 static struct xattr_handler *btrfs_xattr_handler_map[] = {
        [BTRFS_XATTR_INDEX_USER]                = &btrfs_xattr_user_handler,
 #ifdef CONFIG_FS_POSIX_ACL
-//     [BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS]    = &btrfs_xattr_acl_access_handler,
-//     [BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT]   = &btrfs_xattr_acl_default_handler,
+       [BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS]    = &btrfs_xattr_acl_access_handler,
+       [BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT]   = &btrfs_xattr_acl_default_handler,
 #endif
        [BTRFS_XATTR_INDEX_TRUSTED]             = &btrfs_xattr_trusted_handler,
        [BTRFS_XATTR_INDEX_SECURITY]            = &btrfs_xattr_security_handler,
-//     [BTRFS_XATTR_INDEX_SYSTEM]              = &btrfs_xattr_system_handler,
+       [BTRFS_XATTR_INDEX_SYSTEM]              = &btrfs_xattr_system_handler,
 };
+
 struct xattr_handler *btrfs_xattr_handlers[] = {
        &btrfs_xattr_user_handler,
 #ifdef CONFIG_FS_POSIX_ACL
-//     &btrfs_xattr_acl_access_handler,
-//     &btrfs_xattr_acl_default_handler,
+       &btrfs_xattr_acl_access_handler,
+       &btrfs_xattr_acl_default_handler,
 #endif
        &btrfs_xattr_trusted_handler,
        &btrfs_xattr_security_handler,
-//     &btrfs_xattr_system_handler,
+       &btrfs_xattr_system_handler,
        NULL,
 };
 
@@ -237,10 +239,14 @@ int btrfs_xattr_set(struct inode *inode, int name_index,
                        mod = 1;
                        goto out;
                }
-       } else if (flags & XATTR_REPLACE) {
-               /* we couldn't find the attr to replace, so error out */
-               ret = -ENODATA;
-               goto out;
+       } else {
+               btrfs_release_path(root, path);
+
+               if (flags & XATTR_REPLACE) {
+                       /* we couldn't find the attr to replace */
+                       ret = -ENODATA;
+                       goto out;
+               }
        }
 
        /* ok we have to create a completely new xattr */