btrfs: use generic posix ACL infrastructure

Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 28 insertions, 135 deletions

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index b56519d47268..ff9b3995d453 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -35,13 +35,6 @@ struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
         char *value = NULL;
         struct posix_acl *acl;
 
-        if (!IS_POSIXACL(inode))
-                return NULL;
-
-        acl = get_cached_acl(inode, type);
-        if (acl != ACL_NOT_CACHED)
-                return acl;
-
         switch (type) {
         case ACL_TYPE_ACCESS:
                 name = POSIX_ACL_XATTR_ACCESS;
@@ -76,31 +69,10 @@ struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
         return acl;
 }
 
-static int btrfs_xattr_acl_get(struct dentry *dentry, const char *name,
-                void *value, size_t size, int type)
-{
-        struct posix_acl *acl;
-        int ret = 0;
-
-        if (!IS_POSIXACL(dentry->d_inode))
-                return -EOPNOTSUPP;
-
-        acl = btrfs_get_acl(dentry->d_inode, type);
-
-        if (IS_ERR(acl))
-                return PTR_ERR(acl);
-        if (acl == NULL)
-                return -ENODATA;
-        ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
-        posix_acl_release(acl);
-
-        return ret;
-}
-
 /*
  * Needs to be called with fs_mutex held
  */
-static int btrfs_set_acl(struct btrfs_trans_handle *trans,
+static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
                          struct inode *inode, struct posix_acl *acl, int type)
 {
         int ret, size = 0;
@@ -158,35 +130,9 @@ out:
         return ret;
 }
 
-static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
-                const void *value, size_t size, int flags, int type)
+int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
-        int ret;
-        struct posix_acl *acl = NULL;
-
-        if (!inode_owner_or_capable(dentry->d_inode))
-                return -EPERM;
-
-        if (!IS_POSIXACL(dentry->d_inode))
-                return -EOPNOTSUPP;
-
-        if (value) {
-                acl = posix_acl_from_xattr(&init_user_ns, value, size);
-                if (IS_ERR(acl))
-                        return PTR_ERR(acl);
-
-                if (acl) {
-                        ret = posix_acl_valid(acl);
-                        if (ret)
-                                goto out;
-                }
-        }
-
-        ret = btrfs_set_acl(NULL, dentry->d_inode, acl, type);
-out:
-        posix_acl_release(acl);
-
-        return ret;
+        return __btrfs_set_acl(NULL, inode, acl, type);
 }
 
 /*
@@ -197,83 +143,31 @@ out:
 int btrfs_init_acl(struct btrfs_trans_handle *trans,
                    struct inode *inode, struct inode *dir)
 {
-        struct posix_acl *acl = NULL;
+        struct posix_acl *default_acl, *acl;
         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);
-                }
+        ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+        if (ret)
+                return ret;
 
-                if (!acl)
-                        inode->i_mode &= ~current_umask();
+        if (default_acl) {
+                ret = __btrfs_set_acl(trans, inode, default_acl,
+                                      ACL_TYPE_DEFAULT);
+                posix_acl_release(default_acl);
         }
 
-        if (IS_POSIXACL(dir) && acl) {
-                if (S_ISDIR(inode->i_mode)) {
-                        ret = btrfs_set_acl(trans, inode, acl,
-                                            ACL_TYPE_DEFAULT);
-                        if (ret)
-                                goto failed;
-                }
-                ret = __posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
-                if (ret < 0)
-                        return ret;
-
-                if (ret > 0) {
-                        /* we need an acl */
-                        ret = btrfs_set_acl(trans, inode, acl, ACL_TYPE_ACCESS);
-                } else if (ret < 0) {
-                        cache_no_acl(inode);
-                }
-        } else {
-                cache_no_acl(inode);
+        if (acl) {
+                if (!ret)
+                        ret = __btrfs_set_acl(trans, inode, acl,
+                                              ACL_TYPE_ACCESS);
+                posix_acl_release(acl);
         }
-failed:
-        posix_acl_release(acl);
-
-        return ret;
-}
 
-int btrfs_acl_chmod(struct inode *inode)
-{
-        struct posix_acl *acl;
-        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_OR_NULL(acl))
-                return PTR_ERR(acl);
-
-        ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
-        if (ret)
-                return ret;
-        ret = btrfs_set_acl(NULL, inode, acl, ACL_TYPE_ACCESS);
-        posix_acl_release(acl);
+        if (!default_acl && !acl)
+                cache_no_acl(inode);
         return ret;
 }
-
-const struct xattr_handler btrfs_xattr_acl_default_handler = {
-        .prefix = POSIX_ACL_XATTR_DEFAULT,
-        .flags  = ACL_TYPE_DEFAULT,
-        .get    = btrfs_xattr_acl_get,
-        .set    = btrfs_xattr_acl_set,
-};
-
-const struct xattr_handler btrfs_xattr_acl_access_handler = {
-        .prefix = POSIX_ACL_XATTR_ACCESS,
-        .flags  = ACL_TYPE_ACCESS,
-        .get    = btrfs_xattr_acl_get,
-        .set    = btrfs_xattr_acl_set,
-};
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 54ab86127f7a..7506825211a2 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3899,20 +3899,17 @@ do {									\
 /* acl.c */
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 struct posix_acl *btrfs_get_acl(struct inode *inode, int type);
+int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 int btrfs_init_acl(struct btrfs_trans_handle *trans,
                    struct inode *inode, struct inode *dir);
-int btrfs_acl_chmod(struct inode *inode);
 #else
 #define btrfs_get_acl NULL
+#define btrfs_set_acl NULL
 static inline int btrfs_init_acl(struct btrfs_trans_handle *trans,
                                  struct inode *inode, struct inode *dir)
 {
         return 0;
 }
-static inline int btrfs_acl_chmod(struct inode *inode)
-{
-        return 0;
-}
 #endif
 
 /* relocation.c */
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f1a77449d032..b1314300d9fc 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4464,7 +4464,7 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
                 err = btrfs_dirty_inode(inode);
 
                 if (!err && attr->ia_valid & ATTR_MODE)
-                        err = btrfs_acl_chmod(inode);
+                        err = posix_acl_chmod(inode, inode->i_mode);
         }
 
         return err;
@@ -8649,12 +8649,14 @@ static const struct inode_operations btrfs_dir_inode_operations = {
         .removexattr    = btrfs_removexattr,
         .permission     = btrfs_permission,
         .get_acl        = btrfs_get_acl,
+        .set_acl        = btrfs_set_acl,
         .update_time    = btrfs_update_time,
 };
 static const struct inode_operations btrfs_dir_ro_inode_operations = {
         .lookup         = btrfs_lookup,
         .permission     = btrfs_permission,
         .get_acl        = btrfs_get_acl,
+        .set_acl        = btrfs_set_acl,
         .update_time    = btrfs_update_time,
 };
 
@@ -8724,6 +8726,7 @@ static const struct inode_operations btrfs_file_inode_operations = {
         .permission     = btrfs_permission,
         .fiemap         = btrfs_fiemap,
         .get_acl        = btrfs_get_acl,
+        .set_acl        = btrfs_set_acl,
         .update_time    = btrfs_update_time,
 };
 static const struct inode_operations btrfs_special_inode_operations = {
@@ -8735,6 +8738,7 @@ static const struct inode_operations btrfs_special_inode_operations = {
         .listxattr      = btrfs_listxattr,
         .removexattr    = btrfs_removexattr,
         .get_acl        = btrfs_get_acl,
+        .set_acl        = btrfs_set_acl,
         .update_time    = btrfs_update_time,
 };
 static const struct inode_operations btrfs_symlink_inode_operations = {
@@ -8748,7 +8752,6 @@ static const struct inode_operations btrfs_symlink_inode_operations = {
         .getxattr       = btrfs_getxattr,
         .listxattr      = btrfs_listxattr,
         .removexattr    = btrfs_removexattr,
-        .get_acl        = btrfs_get_acl,
         .update_time    = btrfs_update_time,
 };
 
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 05740b9789e4..3d1c301c9260 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -22,6 +22,7 @@
 #include <linux/rwsem.h>
 #include <linux/xattr.h>
 #include <linux/security.h>
+#include <linux/posix_acl_xattr.h>
 #include "ctree.h"
 #include "btrfs_inode.h"
 #include "transaction.h"
@@ -313,8 +314,8 @@ err:
  */
 const struct xattr_handler *btrfs_xattr_handlers[] = {
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
-        &btrfs_xattr_acl_access_handler,
-        &btrfs_xattr_acl_default_handler,
+        &posix_acl_access_xattr_handler,
+        &posix_acl_default_xattr_handler,
 #endif
         NULL,
 };
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
index b3cc8039134b..5049608d1388 100644
--- a/fs/btrfs/xattr.h
+++ b/fs/btrfs/xattr.h
@@ -21,8 +21,6 @@
 
 #include <linux/xattr.h>
 
-extern const struct xattr_handler btrfs_xattr_acl_access_handler;
-extern const struct xattr_handler btrfs_xattr_acl_default_handler;
 extern const struct xattr_handler *btrfs_xattr_handlers[];
 
 extern ssize_t __btrfs_getxattr(struct inode *inode, const char *name,