[XFS] Use the generic xattr methods.

Add missing file fs/xfs/linux-2.6/xfs_xattr.c

SGI-PV: 982343

SGI-Modid: xfs-linux-melb:xfs-kern:31234a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 333 insertions, 0 deletions

diff --git a/fs/xfs/linux-2.6/xfs_xattr.c b/fs/xfs/linux-2.6/xfs_xattr.c
new file mode 100644
index 00000000000..b4acb68fc9f
--- /dev/null
+++ b/fs/xfs/linux-2.6/xfs_xattr.c
@@ -0,0 +1,333 @@
+/*
+ * Copyright (C) 2008 Christoph Hellwig.
+ * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "xfs.h"
+#include "xfs_da_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_inode.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_acl.h"
+#include "xfs_vnodeops.h"
+
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+
+/*
+ * ACL handling.  Should eventually be moved into xfs_acl.c
+ */
+
+static int
+xfs_decode_acl(const char *name)
+{
+        if (strcmp(name, "posix_acl_access") == 0)
+                return _ACL_TYPE_ACCESS;
+        else if (strcmp(name, "posix_acl_default") == 0)
+                return _ACL_TYPE_DEFAULT;
+        return -EINVAL;
+}
+
+/*
+ * Get system extended attributes which at the moment only
+ * includes Posix ACLs.
+ */
+static int
+xfs_xattr_system_get(struct inode *inode, const char *name,
+                void *buffer, size_t size)
+{
+        int acl;
+
+        acl = xfs_decode_acl(name);
+        if (acl < 0)
+                return acl;
+
+        return xfs_acl_vget(inode, buffer, size, acl);
+}
+
+static int
+xfs_xattr_system_set(struct inode *inode, const char *name,
+                const void *value, size_t size, int flags)
+{
+        int error, acl;
+
+        acl = xfs_decode_acl(name);
+        if (acl < 0)
+                return acl;
+        if (flags & XATTR_CREATE)
+                return -EINVAL;
+
+        if (!value)
+                return xfs_acl_vremove(inode, acl);
+
+        error = xfs_acl_vset(inode, (void *)value, size, acl);
+        if (!error)
+                vn_revalidate(inode);
+        return error;
+}
+
+static struct xattr_handler xfs_xattr_system_handler = {
+        .prefix = XATTR_SYSTEM_PREFIX,
+        .get    = xfs_xattr_system_get,
+        .set    = xfs_xattr_system_set,
+};
+
+
+/*
+ * Real xattr handling.  The only difference between the namespaces is
+ * a flag passed to the low-level attr code.
+ */
+
+static int
+__xfs_xattr_get(struct inode *inode, const char *name,
+                void *value, size_t size, int xflags)
+{
+        struct xfs_inode *ip = XFS_I(inode);
+        int error, asize = size;
+
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+
+        /* Convert Linux syscall to XFS internal ATTR flags */
+        if (!size) {
+                xflags |= ATTR_KERNOVAL;
+                value = NULL;
+        }
+
+        error = -xfs_attr_get(ip, name, value, &asize, xflags);
+        if (error)
+                return error;
+        return asize;
+}
+
+static int
+__xfs_xattr_set(struct inode *inode, const char *name, const void *value,
+                size_t size, int flags, int xflags)
+{
+        struct xfs_inode *ip = XFS_I(inode);
+
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+
+        /* Convert Linux syscall to XFS internal ATTR flags */
+        if (flags & XATTR_CREATE)
+                xflags |= ATTR_CREATE;
+        if (flags & XATTR_REPLACE)
+                xflags |= ATTR_REPLACE;
+
+        if (!value)
+                return -xfs_attr_remove(ip, name, xflags);
+        return -xfs_attr_set(ip, name, (void *)value, size, xflags);
+}
+
+static int
+xfs_xattr_user_get(struct inode *inode, const char *name,
+                void *value, size_t size)
+{
+        return __xfs_xattr_get(inode, name, value, size, 0);
+}
+
+static int
+xfs_xattr_user_set(struct inode *inode, const char *name,
+                const void *value, size_t size, int flags)
+{
+        return __xfs_xattr_set(inode, name, value, size, flags, 0);
+}
+
+static struct xattr_handler xfs_xattr_user_handler = {
+        .prefix = XATTR_USER_PREFIX,
+        .get    = xfs_xattr_user_get,
+        .set    = xfs_xattr_user_set,
+};
+
+
+static int
+xfs_xattr_trusted_get(struct inode *inode, const char *name,
+                void *value, size_t size)
+{
+        return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT);
+}
+
+static int
+xfs_xattr_trusted_set(struct inode *inode, const char *name,
+                const void *value, size_t size, int flags)
+{
+        return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT);
+}
+
+static struct xattr_handler xfs_xattr_trusted_handler = {
+        .prefix = XATTR_TRUSTED_PREFIX,
+        .get    = xfs_xattr_trusted_get,
+        .set    = xfs_xattr_trusted_set,
+};
+
+
+static int
+xfs_xattr_secure_get(struct inode *inode, const char *name,
+                void *value, size_t size)
+{
+        return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE);
+}
+
+static int
+xfs_xattr_secure_set(struct inode *inode, const char *name,
+                const void *value, size_t size, int flags)
+{
+        return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE);
+}
+
+static struct xattr_handler xfs_xattr_security_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .get    = xfs_xattr_secure_get,
+        .set    = xfs_xattr_secure_set,
+};
+
+
+struct xattr_handler *xfs_xattr_handlers[] = {
+        &xfs_xattr_user_handler,
+        &xfs_xattr_trusted_handler,
+        &xfs_xattr_security_handler,
+        &xfs_xattr_system_handler,
+        NULL
+};
+
+static unsigned int xfs_xattr_prefix_len(int flags)
+{
+        if (flags & XFS_ATTR_SECURE)
+                return sizeof("security");
+        else if (flags & XFS_ATTR_ROOT)
+                return sizeof("trusted");
+        else
+                return sizeof("user");
+}
+
+static const char *xfs_xattr_prefix(int flags)
+{
+        if (flags & XFS_ATTR_SECURE)
+                return xfs_xattr_security_handler.prefix;
+        else if (flags & XFS_ATTR_ROOT)
+                return xfs_xattr_trusted_handler.prefix;
+        else
+                return xfs_xattr_user_handler.prefix;
+}
+
+static int
+xfs_xattr_put_listent(struct xfs_attr_list_context *context, int flags,
+                char *name, int namelen, int valuelen, char *value)
+{
+        unsigned int prefix_len = xfs_xattr_prefix_len(flags);
+        char *offset;
+        int arraytop;
+
+        ASSERT(context->count >= 0);
+
+        /*
+         * Only show root namespace entries if we are actually allowed to
+         * see them.
+         */
+        if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN))
+                return 0;
+
+        arraytop = context->count + prefix_len + namelen + 1;
+        if (arraytop > context->firstu) {
+                context->count = -1;    /* insufficient space */
+                return 1;
+        }
+        offset = (char *)context->alist + context->count;
+        strncpy(offset, xfs_xattr_prefix(flags), prefix_len);
+        offset += prefix_len;
+        strncpy(offset, name, namelen);                 /* real name */
+        offset += namelen;
+        *offset = '\0';
+        context->count += prefix_len + namelen + 1;
+        return 0;
+}
+
+static int
+xfs_xattr_put_listent_sizes(struct xfs_attr_list_context *context, int flags,
+                char *name, int namelen, int valuelen, char *value)
+{
+        context->count += xfs_xattr_prefix_len(flags) + namelen + 1;
+        return 0;
+}
+
+static int
+list_one_attr(const char *name, const size_t len, void *data,
+                size_t size, ssize_t *result)
+{
+        char *p = data + *result;
+
+        *result += len;
+        if (!size)
+                return 0;
+        if (*result > size)
+                return -ERANGE;
+
+        strcpy(p, name);
+        return 0;
+}
+
+ssize_t
+xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size)
+{
+        struct xfs_attr_list_context context;
+        struct attrlist_cursor_kern cursor = { 0 };
+        struct inode            *inode = dentry->d_inode;
+        int                     error;
+
+        /*
+         * First read the regular on-disk attributes.
+         */
+        memset(&context, 0, sizeof(context));
+        context.dp = XFS_I(inode);
+        context.cursor = &cursor;
+        context.resynch = 1;
+        context.alist = data;
+        context.bufsize = size;
+        context.firstu = context.bufsize;
+
+        if (size)
+                context.put_listent = xfs_xattr_put_listent;
+        else
+                context.put_listent = xfs_xattr_put_listent_sizes;
+
+        xfs_attr_list_int(&context);
+        if (context.count < 0)
+                return -ERANGE;
+
+        /*
+         * Then add the two synthetic ACL attributes.
+         */
+        if (xfs_acl_vhasacl_access(inode)) {
+                error = list_one_attr(POSIX_ACL_XATTR_ACCESS,
+                                strlen(POSIX_ACL_XATTR_ACCESS) + 1,
+                                data, size, &context.count);
+                if (error)
+                        return error;
+        }
+
+        if (xfs_acl_vhasacl_default(inode)) {
+                error = list_one_attr(POSIX_ACL_XATTR_DEFAULT,
+                                strlen(POSIX_ACL_XATTR_DEFAULT) + 1,
+                                data, size, &context.count);
+                if (error)
+                        return error;
+        }
+
+        return context.count;
+}