jfs: use generic posix ACL infrastructure

Copy the scheme I introduced to btrfs many years ago to only use the
xattr handler for ACLs, but pass plain attrs straight through.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

7 files changed, 89 insertions, 140 deletions

diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 28d529ae9a4a..e973b85d6afd 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -72,7 +72,7 @@ struct posix_acl *jfs_get_acl(struct inode *inode, int type)
         return acl;
 }
 
-static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
+static int __jfs_set_acl(tid_t tid, struct inode *inode, int type,
                        struct posix_acl *acl)
 {
         char *ea_name;
@@ -80,21 +80,22 @@ static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
         int size = 0;
         char *value = NULL;
 
-        if (S_ISLNK(inode->i_mode))
-                return -EOPNOTSUPP;
-
-        switch(type) {
-                case ACL_TYPE_ACCESS:
-                        ea_name = POSIX_ACL_XATTR_ACCESS;
-                        break;
-                case ACL_TYPE_DEFAULT:
-                        ea_name = POSIX_ACL_XATTR_DEFAULT;
-                        if (!S_ISDIR(inode->i_mode))
-                                return acl ? -EACCES : 0;
-                        break;
-                default:
-                        return -EINVAL;
+        switch (type) {
+        case ACL_TYPE_ACCESS:
+                ea_name = POSIX_ACL_XATTR_ACCESS;
+                rc = posix_acl_equiv_mode(acl, &inode->i_mode);
+                if (rc < 0)
+                        return rc;
+                if (rc == 0)
+                        acl = NULL;
+                break;
+        case ACL_TYPE_DEFAULT:
+                ea_name = POSIX_ACL_XATTR_DEFAULT;
+                break;
+        default:
+                return -EINVAL;
         }
+
         if (acl) {
                 size = posix_acl_xattr_size(acl->a_count);
                 value = kmalloc(size, GFP_KERNEL);
@@ -114,65 +115,43 @@ out:
         return rc;
 }
 
+int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+        int rc;
+        tid_t tid;
+
+        tid = txBegin(inode->i_sb, 0);
+        mutex_lock(&JFS_IP(inode)->commit_mutex);
+        rc = __jfs_set_acl(tid, inode, type, acl);
+        if (!rc)
+                rc = txCommit(tid, 1, &inode, 0);
+        txEnd(tid);
+        mutex_unlock(&JFS_IP(inode)->commit_mutex);
+        return rc;
+}
+
 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 {
-        struct posix_acl *acl = NULL;
+        struct posix_acl *default_acl, *acl;
         int rc = 0;
 
-        if (S_ISLNK(inode->i_mode))
-                return 0;
+        rc = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+        if (rc)
+                return rc;
 
-        acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
-        if (IS_ERR(acl))
-                return PTR_ERR(acl);
+        if (default_acl) {
+                rc = __jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, default_acl);
+                posix_acl_release(default_acl);
+        }
 
         if (acl) {
-                if (S_ISDIR(inode->i_mode)) {
-                        rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
-                        if (rc)
-                                goto cleanup;
-                }
-                rc = __posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
-                if (rc < 0)
-                        goto cleanup; /* posix_acl_release(NULL) is no-op */
-                if (rc > 0)
-                        rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
-cleanup:
+                if (!rc)
+                        rc = __jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
                 posix_acl_release(acl);
-        } else
-                inode->i_mode &= ~current_umask();
+        }
 
         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
                                inode->i_mode;
 
         return rc;
 }
-
-int jfs_acl_chmod(struct inode *inode)
-{
-        struct posix_acl *acl;
-        int rc;
-        tid_t tid;
-
-        if (S_ISLNK(inode->i_mode))
-                return -EOPNOTSUPP;
-
-        acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
-        if (IS_ERR(acl) || !acl)
-                return PTR_ERR(acl);
-
-        rc = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
-        if (rc)
-                return rc;
-
-        tid = txBegin(inode->i_sb, 0);
-        mutex_lock(&JFS_IP(inode)->commit_mutex);
-        rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
-        if (!rc)
-                rc = txCommit(tid, 1, &inode, 0);
-        txEnd(tid);
-        mutex_unlock(&JFS_IP(inode)->commit_mutex);
-
-        posix_acl_release(acl);
-        return rc;
-}
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index dd7442c58358..794da944d5cd 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -19,6 +19,7 @@
 
 #include <linux/mm.h>
 #include <linux/fs.h>
+#include <linux/posix_acl.h>
 #include <linux/quotaops.h>
 #include "jfs_incore.h"
 #include "jfs_inode.h"
@@ -131,7 +132,7 @@ int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
         mark_inode_dirty(inode);
 
         if (iattr->ia_valid & ATTR_MODE)
-                rc = jfs_acl_chmod(inode);
+                rc = posix_acl_chmod(inode, inode->i_mode);
         return rc;
 }
 
@@ -143,6 +144,7 @@ const struct inode_operations jfs_file_inode_operations = {
         .setattr        = jfs_setattr,
 #ifdef CONFIG_JFS_POSIX_ACL
         .get_acl        = jfs_get_acl,
+        .set_acl        = jfs_set_acl,
 #endif
 };
 
diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h
index ad84fe50ca9e..489f993b7b13 100644
--- a/fs/jfs/jfs_acl.h
+++ b/fs/jfs/jfs_acl.h
@@ -21,8 +21,8 @@
 #ifdef CONFIG_JFS_POSIX_ACL
 
 struct posix_acl *jfs_get_acl(struct inode *inode, int type);
+int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 int jfs_init_acl(tid_t, struct inode *, struct inode *);
-int jfs_acl_chmod(struct inode *inode);
 
 #else
 
@@ -32,10 +32,5 @@ static inline int jfs_init_acl(tid_t tid, struct inode *inode,
         return 0;
 }
 
-static inline int jfs_acl_chmod(struct inode *inode)
-{
-        return 0;
-}
-
 #endif
 #endif          /* _H_JFS_ACL */
diff --git a/fs/jfs/jfs_xattr.h b/fs/jfs/jfs_xattr.h
index e9e100fd7c09..e8d717dabca3 100644
--- a/fs/jfs/jfs_xattr.h
+++ b/fs/jfs/jfs_xattr.h
@@ -61,6 +61,8 @@ extern ssize_t jfs_getxattr(struct dentry *, const char *, void *, size_t);
 extern ssize_t jfs_listxattr(struct dentry *, char *, size_t);
 extern int jfs_removexattr(struct dentry *, const char *);
 
+extern const struct xattr_handler *jfs_xattr_handlers[];
+
 #ifdef CONFIG_JFS_SECURITY
 extern int jfs_init_security(tid_t, struct inode *, struct inode *,
                              const struct qstr *);
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index aa8a3370631b..d59c7defb1ef 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1524,6 +1524,7 @@ const struct inode_operations jfs_dir_inode_operations = {
         .setattr        = jfs_setattr,
 #ifdef CONFIG_JFS_POSIX_ACL
         .get_acl        = jfs_get_acl,
+        .set_acl        = jfs_set_acl,
 #endif
 };
 
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 6669aa2042c3..e2b7483444fd 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -44,6 +44,7 @@
 #include "jfs_imap.h"
 #include "jfs_acl.h"
 #include "jfs_debug.h"
+#include "jfs_xattr.h"
 
 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
@@ -522,6 +523,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
          */
         sb->s_op = &jfs_super_operations;
         sb->s_export_op = &jfs_export_operations;
+        sb->s_xattr = jfs_xattr_handlers;
 #ifdef CONFIG_QUOTA
         sb->dq_op = &dquot_operations;
         sb->s_qcop = &dquot_quotactl_ops;
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index d3472f4cd530..5324e4e2b992 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -666,81 +666,12 @@ static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
 }
 
 /*
- * can_set_system_xattr
- *
- * This code is specific to the system.* namespace.  It contains policy
- * which doesn't belong in the main xattr codepath.
- */
-static int can_set_system_xattr(struct inode *inode, const char *name,
-                                const void *value, size_t value_len)
-{
-#ifdef CONFIG_JFS_POSIX_ACL
-        struct posix_acl *acl;
-        int rc;
-
-        if (!inode_owner_or_capable(inode))
-                return -EPERM;
-
-        /*
-         * POSIX_ACL_XATTR_ACCESS is tied to i_mode
-         */
-        if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
-                acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
-                if (IS_ERR(acl)) {
-                        rc = PTR_ERR(acl);
-                        printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
-                               rc);
-                        return rc;
-                }
-                if (acl) {
-                        rc = posix_acl_equiv_mode(acl, &inode->i_mode);
-                        posix_acl_release(acl);
-                        if (rc < 0) {
-                                printk(KERN_ERR
-                                       "posix_acl_equiv_mode returned %d\n",
-                                       rc);
-                                return rc;
-                        }
-                        mark_inode_dirty(inode);
-                }
-                /*
-                 * We're changing the ACL.  Get rid of the cached one
-                 */
-                forget_cached_acl(inode, ACL_TYPE_ACCESS);
-
-                return 0;
-        } else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
-                acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
-                if (IS_ERR(acl)) {
-                        rc = PTR_ERR(acl);
-                        printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
-                               rc);
-                        return rc;
-                }
-                posix_acl_release(acl);
-
-                /*
-                 * We're changing the default ACL.  Get rid of the cached one
-                 */
-                forget_cached_acl(inode, ACL_TYPE_DEFAULT);
-
-                return 0;
-        }
-#endif                  /* CONFIG_JFS_POSIX_ACL */
-        return -EOPNOTSUPP;
-}
-
-/*
  * Most of the permission checking is done by xattr_permission in the vfs.
- * The local file system is responsible for handling the system.* namespace.
  * We also need to verify that this is a namespace that we recognize.
  */
 static int can_set_xattr(struct inode *inode, const char *name,
                          const void *value, size_t value_len)
 {
-        if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
-                return can_set_system_xattr(inode, name, value, value_len);
-
         if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
                 /*
                  * This makes sure that we aren't trying to set an
@@ -748,7 +679,7 @@ static int can_set_xattr(struct inode *inode, const char *name,
                  * with "os2."
                  */
                 if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
-                                return -EOPNOTSUPP;
+                        return -EOPNOTSUPP;
                 return 0;
         }
 
@@ -913,6 +844,14 @@ int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
         if ((rc = can_set_xattr(inode, name, value, value_len)))
                 return rc;
 
+        /*
+         * If this is a request for a synthetic attribute in the system.*
+         * namespace use the generic infrastructure to resolve a handler
+         * for it via sb->s_xattr.
+         */
+        if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+                return generic_setxattr(dentry, name, value, value_len, flags);
+
         if (value == NULL) {    /* empty EA, do not remove */
                 value = "";
                 value_len = 0;
@@ -986,6 +925,14 @@ ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
 {
         int err;
 
+        /*
+         * If this is a request for a synthetic attribute in the system.*
+         * namespace use the generic infrastructure to resolve a handler
+         * for it via sb->s_xattr.
+         */
+        if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+                return generic_getxattr(dentry, name, data, buf_size);
+
         if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
                 /*
                  * skip past "os2." prefix
@@ -1077,6 +1024,14 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
         if ((rc = can_set_xattr(inode, name, NULL, 0)))
                 return rc;
 
+        /*
+         * If this is a request for a synthetic attribute in the system.*
+         * namespace use the generic infrastructure to resolve a handler
+         * for it via sb->s_xattr.
+         */
+        if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+                return generic_removexattr(dentry, name);
+
         tid = txBegin(inode->i_sb, 0);
         mutex_lock(&ji->commit_mutex);
         rc = __jfs_setxattr(tid, dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
@@ -1088,6 +1043,19 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
         return rc;
 }
 
+/*
+ * List of handlers for synthetic system.* attributes.  All real ondisk
+ * attributes are handled directly.
+ */
+const struct xattr_handler *jfs_xattr_handlers[] = {
+#ifdef JFS_POSIX_ACL
+        &posix_acl_access_xattr_handler,
+        &posix_acl_default_xattr_handler,
+#endif
+        NULL,
+};
+
+
 #ifdef CONFIG_JFS_SECURITY
 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
                           void *fs_info)