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authorAndreas Gruenbacher <agruenba@redhat.com>2016-04-22 14:43:48 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2016-05-12 22:29:18 -0400
commit6c8f980c75185f8ba897814363d21882f7453f53 (patch)
treeefbb19e3dbfdf9d019d0726724fb8a216166586f /fs
parent1a39ba99b5d533647c5dac45cd6a3e0baa7cb66a (diff)
jfs: Clean up xattr name mapping
Instead of stripping "os2." prefixes in __jfs_setxattr, make callers strip them, as __jfs_getxattr already does. With that change, use the same name mapping function in jfs_{get,set,remove}xattr. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/jfs/xattr.c80
1 files changed, 25 insertions, 55 deletions
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index 5becc6a3ff8c..9cdf7dc4d5cb 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -86,6 +86,14 @@ struct ea_buffer {
#define EA_MALLOC 0x0008
+/*
+ * Mapping of on-disk attribute names: for on-disk attribute names with an
+ * unknown prefix (not "system.", "user.", "security.", or "trusted."), the
+ * prefix "os2." is prepended. On the way back to disk, "os2." prefixes are
+ * stripped and we make sure that the remaining name does not start with one
+ * of the know prefixes.
+ */
+
static int is_known_namespace(const char *name)
{
if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
@@ -97,29 +105,19 @@ static int is_known_namespace(const char *name)
return true;
}
-/*
- * These three routines are used to recognize on-disk extended attributes
- * that are in a recognized namespace. If the attribute is not recognized,
- * "os2." is prepended to the name
- */
-static int is_os2_xattr(struct jfs_ea *ea)
-{
- return !is_known_namespace(ea->name);
-}
-
static inline int name_size(struct jfs_ea *ea)
{
- if (is_os2_xattr(ea))
- return ea->namelen + XATTR_OS2_PREFIX_LEN;
- else
+ if (is_known_namespace(ea->name))
return ea->namelen;
+ else
+ return ea->namelen + XATTR_OS2_PREFIX_LEN;
}
static inline int copy_name(char *buffer, struct jfs_ea *ea)
{
int len = ea->namelen;
- if (is_os2_xattr(ea)) {
+ if (!is_known_namespace(ea->name)) {
memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
buffer += XATTR_OS2_PREFIX_LEN;
len += XATTR_OS2_PREFIX_LEN;
@@ -669,29 +667,24 @@ static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
* Most of the permission checking is done by xattr_permission in the vfs.
* 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)
+static bool map_name_to_disk(const char **name)
{
- if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
+ if (!strncmp(*name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
/*
* This makes sure that we aren't trying to set an
* attribute in a different namespace by prefixing it
* with "os2."
*/
- if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
- return -EOPNOTSUPP;
- return 0;
+ if (is_known_namespace(*name + XATTR_OS2_PREFIX_LEN))
+ return false;
+ *name += XATTR_OS2_PREFIX_LEN;
+ return true;
}
/*
* Don't allow setting an attribute in an unknown namespace.
*/
- if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
- strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
- strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
- return -EOPNOTSUPP;
-
- return 0;
+ return is_known_namespace(*name);
}
int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
@@ -704,21 +697,10 @@ int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
int xattr_size;
int new_size;
int namelen = strlen(name);
- char *os2name = NULL;
int found = 0;
int rc;
int length;
- if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
- os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
- GFP_KERNEL);
- if (!os2name)
- return -ENOMEM;
- strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
- name = os2name;
- namelen -= XATTR_OS2_PREFIX_LEN;
- }
-
down_write(&JFS_IP(inode)->xattr_sem);
xattr_size = ea_get(inode, &ea_buf, 0);
@@ -841,8 +823,6 @@ int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
out:
up_write(&JFS_IP(inode)->xattr_sem);
- kfree(os2name);
-
return rc;
}
@@ -862,8 +842,8 @@ int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
return generic_setxattr(dentry, name, value, value_len, flags);
- if ((rc = can_set_xattr(inode, name, value, value_len)))
- return rc;
+ if (!map_name_to_disk(&name))
+ return -EOPNOTSUPP;
if (value == NULL) { /* empty EA, do not remove */
value = "";
@@ -946,18 +926,8 @@ ssize_t jfs_getxattr(struct dentry *dentry, struct inode *inode,
if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
return generic_getxattr(dentry, inode, name, data, buf_size);
- if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
- /*
- * skip past "os2." prefix
- */
- name += XATTR_OS2_PREFIX_LEN;
- /*
- * Don't allow retrieving properly prefixed attributes
- * by prepending them with "os2."
- */
- if (is_known_namespace(name))
- return -EOPNOTSUPP;
- }
+ if (!map_name_to_disk(&name))
+ return -EOPNOTSUPP;
err = __jfs_getxattr(inode, name, data, buf_size);
@@ -1042,8 +1012,8 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
return generic_removexattr(dentry, name);
- if ((rc = can_set_xattr(inode, name, NULL, 0)))
- return rc;
+ if (!map_name_to_disk(&name))
+ return -EOPNOTSUPP;
tid = txBegin(inode->i_sb, 0);
mutex_lock(&ji->commit_mutex);