GFS2: Fix up system xattrs
authorSteven Whitehouse <swhiteho@redhat.com>
Fri, 2 Oct 2009 10:50:54 +0000 (11:50 +0100)
committerSteven Whitehouse <swhiteho@redhat.com>
Thu, 3 Dec 2009 11:43:05 +0000 (11:43 +0000)
This code has been shamelessly stolen from XFS at the suggestion
of Christoph Hellwig. I've not added support for cached ACLs so
far... watch for that in a later patch, although this is designed
in such a way that they should be easy to add.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
fs/gfs2/acl.c
fs/gfs2/acl.h
fs/gfs2/xattr.c

index 3fc4e3ac7d84efdc76b4ddbae91f82f90f8c257d..2168da1216475b2b9d3a9611730b77c89a3022d4 100644 (file)
@@ -12,6 +12,7 @@
 #include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/buffer_head.h>
+#include <linux/xattr.h>
 #include <linux/posix_acl.h>
 #include <linux/posix_acl_xattr.h>
 #include <linux/gfs2_ondisk.h>
 #include "trans.h"
 #include "util.h"
 
-#define ACL_ACCESS 1
-#define ACL_DEFAULT 0
-
-int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
-                         struct gfs2_ea_request *er, int *remove, mode_t *mode)
-{
-       struct posix_acl *acl;
-       int error;
-
-       error = gfs2_acl_validate_remove(ip, access);
-       if (error)
-               return error;
-
-       if (!er->er_data)
-               return -EINVAL;
-
-       acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
-       if (IS_ERR(acl))
-               return PTR_ERR(acl);
-       if (!acl) {
-               *remove = 1;
-               return 0;
-       }
-
-       error = posix_acl_valid(acl);
-       if (error)
-               goto out;
-
-       if (access) {
-               error = posix_acl_equiv_mode(acl, mode);
-               if (!error)
-                       *remove = 1;
-               else if (error > 0)
-                       error = 0;
-       }
-
-out:
-       posix_acl_release(acl);
-       return error;
-}
-
-int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
-{
-       if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
-               return -EOPNOTSUPP;
-       if (!is_owner_or_cap(&ip->i_inode))
-               return -EPERM;
-       if (S_ISLNK(ip->i_inode.i_mode))
-               return -EOPNOTSUPP;
-       if (!access && !S_ISDIR(ip->i_inode.i_mode))
-               return -EACCES;
-
-       return 0;
-}
-
 static int acl_get(struct gfs2_inode *ip, const char *name,
                   struct posix_acl **acl, struct gfs2_ea_location *el,
                   char **datap, unsigned int *lenp)
@@ -277,3 +223,117 @@ out_brelse:
        return error;
 }
 
+static int gfs2_acl_type(const char *name)
+{
+       if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
+               return ACL_TYPE_ACCESS;
+       if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
+               return ACL_TYPE_DEFAULT;
+       return -EINVAL;
+}
+
+static int gfs2_xattr_system_get(struct inode *inode, const char *name,
+                                void *buffer, size_t size)
+{
+       int type;
+
+       type = gfs2_acl_type(name);
+       if (type < 0)
+               return type;
+
+       return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
+}
+
+static int gfs2_set_mode(struct inode *inode, mode_t mode)
+{
+       int error = 0;
+
+       if (mode != inode->i_mode) {
+               struct iattr iattr;
+
+               iattr.ia_valid = ATTR_MODE;
+               iattr.ia_mode = mode;
+
+               error = gfs2_setattr_simple(GFS2_I(inode), &iattr);
+       }
+
+       return error;
+}
+
+static int gfs2_xattr_system_set(struct inode *inode, const char *name,
+                                const void *value, size_t size, int flags)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(inode);
+       struct posix_acl *acl = NULL;
+       int error = 0, type;
+
+       if (!sdp->sd_args.ar_posix_acl)
+               return -EOPNOTSUPP;
+
+       type = gfs2_acl_type(name);
+       if (type < 0)
+               return type;
+       if (flags & XATTR_CREATE)
+               return -EINVAL;
+       if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
+               return value ? -EACCES : 0;
+       if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
+               return -EPERM;
+       if (S_ISLNK(inode->i_mode))
+               return -EOPNOTSUPP;
+
+       if (!value)
+               goto set_acl;
+
+       acl = posix_acl_from_xattr(value, size);
+       if (!acl) {
+               /*
+                * acl_set_file(3) may request that we set default ACLs with
+                * zero length -- defend (gracefully) against that here.
+                */
+               goto out;
+       }
+       if (IS_ERR(acl)) {
+               error = PTR_ERR(acl);
+               goto out;
+       }
+
+       error = posix_acl_valid(acl);
+       if (error)
+               goto out_release;
+
+       error = -EINVAL;
+       if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
+               goto out_release;
+
+       if (type == ACL_TYPE_ACCESS) {
+               mode_t mode = inode->i_mode;
+               error = posix_acl_equiv_mode(acl, &mode);
+
+               if (error <= 0) {
+                       posix_acl_release(acl);
+                       acl = NULL;
+
+                       if (error < 0)
+                               return error;
+               }
+
+               error = gfs2_set_mode(inode, mode);
+               if (error)
+                       goto out_release;
+       }
+
+set_acl:
+       error = gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, 0);
+out_release:
+       posix_acl_release(acl);
+out:
+       return error;
+}
+
+struct xattr_handler gfs2_xattr_system_handler = {
+       .prefix = XATTR_SYSTEM_PREFIX,
+       .get    = gfs2_xattr_system_get,
+       .set    = gfs2_xattr_system_set,
+};
+
index 6751930bfb648e809eb90e028c0caa8458e1e5e8..cc954390b6daf3e633dd13d9bbb80982baf685a2 100644 (file)
 #include "incore.h"
 
 #define GFS2_POSIX_ACL_ACCESS          "posix_acl_access"
-#define GFS2_POSIX_ACL_ACCESS_LEN      16
 #define GFS2_POSIX_ACL_DEFAULT         "posix_acl_default"
-#define GFS2_POSIX_ACL_DEFAULT_LEN     17
+#define GFS2_ACL_MAX_ENTRIES           25
 
-#define GFS2_ACL_IS_ACCESS(name, len) \
-         ((len) == GFS2_POSIX_ACL_ACCESS_LEN && \
-         !memcmp(GFS2_POSIX_ACL_ACCESS, (name), (len)))
-
-#define GFS2_ACL_IS_DEFAULT(name, len) \
-         ((len) == GFS2_POSIX_ACL_DEFAULT_LEN && \
-         !memcmp(GFS2_POSIX_ACL_DEFAULT, (name), (len)))
-
-struct gfs2_ea_request;
-
-int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
-                         struct gfs2_ea_request *er,
-                         int *remove, mode_t *mode);
-int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access);
-int gfs2_check_acl(struct inode *inode, int mask);
-int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip);
-int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
+extern int gfs2_check_acl(struct inode *inode, int mask);
+extern int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip);
+extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
+extern struct xattr_handler gfs2_xattr_system_handler;
 
 #endif /* __ACL_DOT_H__ */
index 8a0f8ef6ee2700cc5ef62f5090b11d602b9f8b20..6b803540951ef9c37c905bf1197d51c0f065425e 100644 (file)
@@ -1507,18 +1507,6 @@ static int gfs2_xattr_user_set(struct inode *inode, const char *name,
        return gfs2_xattr_set(inode, GFS2_EATYPE_USR, name, value, size, flags);
 }
 
-static int gfs2_xattr_system_get(struct inode *inode, const char *name,
-                                void *buffer, size_t size)
-{
-       return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
-}
-
-static int gfs2_xattr_system_set(struct inode *inode, const char *name,
-                                const void *value, size_t size, int flags)
-{
-       return gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, flags);
-}
-
 static int gfs2_xattr_security_get(struct inode *inode, const char *name,
                                   void *buffer, size_t size)
 {
@@ -1543,12 +1531,6 @@ static struct xattr_handler gfs2_xattr_security_handler = {
        .set    = gfs2_xattr_security_set,
 };
 
-static struct xattr_handler gfs2_xattr_system_handler = {
-       .prefix = XATTR_SYSTEM_PREFIX,
-       .get    = gfs2_xattr_system_get,
-       .set    = gfs2_xattr_system_set,
-};
-
 struct xattr_handler *gfs2_xattr_handlers[] = {
        &gfs2_xattr_user_handler,
        &gfs2_xattr_security_handler,