[PATCH 05/10] btrfs: Use xattr handler infrastructure

From: Andreas Gruenbacher
Date: Mon Nov 30 2015 - 16:44:19 EST


Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem.

Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <jbacik@xxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: linux-btrfs@xxxxxxxxxxxxxxx
---
fs/btrfs/inode.c | 8 +--
fs/btrfs/xattr.c | 166 ++++++++++++++++++++-----------------------------------
fs/btrfs/xattr.h | 2 -
3 files changed, 63 insertions(+), 113 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d540fd7..4fb8d6e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9994,7 +9994,7 @@ static const struct inode_operations btrfs_dir_inode_operations = {
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.setxattr = btrfs_setxattr,
- .getxattr = btrfs_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
@@ -10071,7 +10071,7 @@ static const struct inode_operations btrfs_file_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.setxattr = btrfs_setxattr,
- .getxattr = btrfs_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
@@ -10085,7 +10085,7 @@ static const struct inode_operations btrfs_special_inode_operations = {
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
- .getxattr = btrfs_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.get_acl = btrfs_get_acl,
@@ -10100,7 +10100,7 @@ static const struct inode_operations btrfs_symlink_inode_operations = {
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
- .getxattr = btrfs_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.update_time = btrfs_update_time,
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 1fcd7b6..7cbef1a 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -351,137 +351,89 @@ err:
return ret;
}

-/*
- * List of handlers for synthetic system.* attributes. All real ondisk
- * attributes are handled directly.
- */
-const struct xattr_handler *btrfs_xattr_handlers[] = {
-#ifdef CONFIG_BTRFS_FS_POSIX_ACL
- &posix_acl_access_xattr_handler,
- &posix_acl_default_xattr_handler,
-#endif
- NULL,
-};
-
-/*
- * Check if the attribute is in a supported namespace.
- *
- * This is applied after the check for the synthetic attributes in the system
- * namespace.
- */
-static int btrfs_is_valid_xattr(const char *name)
+static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
{
- int len = strlen(name);
- int prefixlen = 0;
-
- if (!strncmp(name, XATTR_SECURITY_PREFIX,
- XATTR_SECURITY_PREFIX_LEN))
- prefixlen = XATTR_SECURITY_PREFIX_LEN;
- else if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
- prefixlen = XATTR_SYSTEM_PREFIX_LEN;
- else if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
- prefixlen = XATTR_TRUSTED_PREFIX_LEN;
- else if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
- prefixlen = XATTR_USER_PREFIX_LEN;
- else if (!strncmp(name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN))
- prefixlen = XATTR_BTRFS_PREFIX_LEN;
- else
- return -EOPNOTSUPP;
-
- /*
- * The name cannot consist of just prefix
- */
- if (len <= prefixlen)
- return -EINVAL;
+ struct inode *inode = d_inode(dentry);

- return 0;
+ name = xattr_full_name(handler, name);
+ return __btrfs_getxattr(inode, name, buffer, size);
}

-ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
- void *buffer, size_t size)
+static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ const void *buffer, size_t size,
+ int flags)
{
- int ret;
+ struct inode *inode = d_inode(dentry);

- /*
- * 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, buffer, size);
+ name = xattr_full_name(handler, name);
+ return __btrfs_setxattr(NULL, inode, name, buffer, size, flags);
+}

- ret = btrfs_is_valid_xattr(name);
- if (ret)
- return ret;
- return __btrfs_getxattr(d_inode(dentry), name, buffer, size);
+static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ name = xattr_full_name(handler, name);
+ return btrfs_set_prop(d_inode(dentry), name, value, size, flags);
}

+static const struct xattr_handler btrfs_security_xattr_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = btrfs_xattr_handler_get,
+ .set = btrfs_xattr_handler_set,
+};
+
+static const struct xattr_handler btrfs_trusted_xattr_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .get = btrfs_xattr_handler_get,
+ .set = btrfs_xattr_handler_set,
+};
+
+static const struct xattr_handler btrfs_user_xattr_handler = {
+ .prefix = XATTR_USER_PREFIX,
+ .get = btrfs_xattr_handler_get,
+ .set = btrfs_xattr_handler_set,
+};
+
+static const struct xattr_handler btrfs_btrfs_xattr_handler = {
+ .prefix = XATTR_BTRFS_PREFIX,
+ .get = btrfs_xattr_handler_get,
+ .set = btrfs_xattr_handler_set_prop,
+};
+
+const struct xattr_handler *btrfs_xattr_handlers[] = {
+ &btrfs_security_xattr_handler,
+#ifdef CONFIG_BTRFS_FS_POSIX_ACL
+ &posix_acl_access_xattr_handler,
+ &posix_acl_default_xattr_handler,
+#endif
+ &btrfs_trusted_xattr_handler,
+ &btrfs_user_xattr_handler,
+ &btrfs_btrfs_xattr_handler,
+ NULL,
+};
+
int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root;
- int ret;

- /*
- * The permission on security.* and system.* is not checked
- * in permission().
- */
if (btrfs_root_readonly(root))
return -EROFS;
-
- /*
- * 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, size, flags);
-
- ret = btrfs_is_valid_xattr(name);
- if (ret)
- return ret;
-
- if (!strncmp(name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN))
- return btrfs_set_prop(d_inode(dentry), name,
- value, size, flags);
-
- if (size == 0)
- value = ""; /* empty EA, do not remove */
-
- return __btrfs_setxattr(NULL, d_inode(dentry), name, value, size,
- flags);
+ return generic_setxattr(dentry, name, value, size, flags);
}

int btrfs_removexattr(struct dentry *dentry, const char *name)
{
struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root;
- int ret;

- /*
- * The permission on security.* and system.* is not checked
- * in permission().
- */
if (btrfs_root_readonly(root))
return -EROFS;
-
- /*
- * 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);
-
- ret = btrfs_is_valid_xattr(name);
- if (ret)
- return ret;
-
- if (!strncmp(name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN))
- return btrfs_set_prop(d_inode(dentry), name,
- NULL, 0, XATTR_REPLACE);
-
- return __btrfs_setxattr(NULL, d_inode(dentry), name, NULL, 0,
- XATTR_REPLACE);
+ return generic_removexattr(dentry, name);
}

static int btrfs_initxattrs(struct inode *inode,
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
index 5049608..96807b3 100644
--- a/fs/btrfs/xattr.h
+++ b/fs/btrfs/xattr.h
@@ -28,8 +28,6 @@ extern ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
extern int __btrfs_setxattr(struct btrfs_trans_handle *trans,
struct inode *inode, const char *name,
const void *value, size_t size, int flags);
-extern ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
- void *buffer, size_t size);
extern int btrfs_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags);
extern int btrfs_removexattr(struct dentry *dentry, const char *name);
--
2.5.0

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