Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem. For implementing shmem_xattr_handler_set, we need a
version of simple_xattr_set which removes the attribute when value is
NULL. Use this to implement kernfs_iop_removexattr as well.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
---
fs/kernfs/inode.c | 2 +-
fs/xattr.c | 48 ++++++------------
include/linux/xattr.h | 4 +-
mm/shmem.c | 131 ++++++++++++++++----------------------------------
4 files changed, 60 insertions(+), 125 deletions(-)
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 756dd56..f97e1f7 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -205,7 +205,7 @@ int kernfs_iop_removexattr(struct dentry *dentry, const char *name)
if (!attrs)
return -ENOMEM;
- return simple_xattr_remove(&attrs->xattrs, name);
+ return simple_xattr_set(&attrs->xattrs, name, NULL, 0, XATTR_REPLACE);
}
ssize_t kernfs_iop_getxattr(struct dentry *dentry, const char *name, void *buf,
diff --git a/fs/xattr.c b/fs/xattr.c
index aaea9e4..1a1ddd7 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -851,8 +851,22 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
return ret;
}
-static int __simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
- const void *value, size_t size, int flags)
+/**
+ * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
+ * @xattrs: target simple_xattr list
+ * @name: name of the extended attribute
+ * @value: value of the xattr. If %NULL, will remove the attribute.
+ * @size: size of the new xattr
+ * @flags: %XATTR_{CREATE|REPLACE}
+ *
+ * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
+ * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist;
+ * otherwise, fails with -ENODATA.
+ *
+ * Returns 0 on success, -errno on failure.
+ */
+int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
+ const void *value, size_t size, int flags)
{
struct simple_xattr *xattr;
struct simple_xattr *new_xattr = NULL;
@@ -902,36 +916,6 @@ out:
}
-/**
- * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
- * @xattrs: target simple_xattr list
- * @name: name of the new extended attribute
- * @value: value of the new xattr. If %NULL, will remove the attribute
- * @size: size of the new xattr
- * @flags: %XATTR_{CREATE|REPLACE}
- *
- * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
- * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist;
- * otherwise, fails with -ENODATA.
- *
- * Returns 0 on success, -errno on failure.
- */
-int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
- const void *value, size_t size, int flags)
-{
- if (size == 0)
- value = ""; /* empty EA, do not remove */
- return __simple_xattr_set(xattrs, name, value, size, flags);
-}
-
-/*
- * xattr REMOVE operation for in-memory/pseudo filesystems
- */
-int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name)
-{
- return __simple_xattr_set(xattrs, name, NULL, 0, XATTR_REPLACE);
-}
-
static bool xattr_is_trusted(const char *name)
{
return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 3099e16..46826c7 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -99,9 +99,7 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
void *buffer, size_t size);
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
const void *value, size_t size, int flags);
-int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name);
-ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
- size_t size);
+ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer, size_t size);
void simple_xattr_list_add(struct simple_xattrs *xattrs,
struct simple_xattr *new_xattr);
diff --git a/mm/shmem.c b/mm/shmem.c
index 9187eee..fdfe6c8 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2561,94 +2561,47 @@ static int shmem_initxattrs(struct inode *inode,
return 0;
}
-static const struct xattr_handler *shmem_xattr_handlers[] = {
-#ifdef CONFIG_TMPFS_POSIX_ACL
- &posix_acl_access_xattr_handler,
- &posix_acl_default_xattr_handler,
-#endif
- NULL
-};
-
-static int shmem_xattr_validate(const char *name)
-{
- struct { const char *prefix; size_t len; } arr[] = {
- { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN },
- { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN }
- };
- int i;
-
- for (i = 0; i < ARRAY_SIZE(arr); i++) {
- size_t preflen = arr[i].len;
- if (strncmp(name, arr[i].prefix, preflen) == 0) {
- if (!name[preflen])
- return -EINVAL;
- return 0;
- }
- }
- return -EOPNOTSUPP;
-}
-
-static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
- void *buffer, size_t size)
+static int shmem_xattr_handler_get(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
{
struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
- 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, buffer, size);
-
- err = shmem_xattr_validate(name);
- if (err)
- return err;
+ name = xattr_full_name(handler, name);
return simple_xattr_get(&info->xattrs, name, buffer, size);
}
-static int shmem_setxattr(struct dentry *dentry, const char *name,
- const void *value, size_t size, int flags)
+static int shmem_xattr_handler_set(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
{
struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
- 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_setxattr(dentry, name, value, size, flags);
-
- err = shmem_xattr_validate(name);
- if (err)
- return err;
+ name = xattr_full_name(handler, name);
return simple_xattr_set(&info->xattrs, name, value, size, flags);
}
-static int shmem_removexattr(struct dentry *dentry, const char *name)
-{
- struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
- 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_removexattr(dentry, name);
+static const struct xattr_handler shmem_security_xattr_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = shmem_xattr_handler_get,
+ .set = shmem_xattr_handler_set,
+};
- err = shmem_xattr_validate(name);
- if (err)
- return err;
+static const struct xattr_handler shmem_trusted_xattr_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .get = shmem_xattr_handler_get,
+ .set = shmem_xattr_handler_set,
+};
- return simple_xattr_remove(&info->xattrs, name);
-}
+static const struct xattr_handler *shmem_xattr_handlers[] = {
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ &posix_acl_access_xattr_handler,
+ &posix_acl_default_xattr_handler,
+#endif
+ &shmem_security_xattr_handler,
+ &shmem_trusted_xattr_handler,
+ NULL
+};
static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
@@ -2661,10 +2614,10 @@ static const struct inode_operations shmem_short_symlink_operations = {
.readlink = generic_readlink,
.follow_link = simple_follow_link,
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
};
@@ -2673,10 +2626,10 @@ static const struct inode_operations shmem_symlink_inode_operations = {
.follow_link = shmem_follow_link,
.put_link = shmem_put_link,
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
};
@@ -3148,10 +3101,10 @@ static const struct inode_operations shmem_inode_operations = {
.getattr = shmem_getattr,
.setattr = shmem_setattr,
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
.set_acl = simple_set_acl,
#endif
};
@@ -3170,10 +3123,10 @@ static const struct inode_operations shmem_dir_inode_operations = {
.tmpfile = shmem_tmpfile,
#endif
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
.setattr = shmem_setattr,
@@ -3183,10 +3136,10 @@ static const struct inode_operations shmem_dir_inode_operations = {
static const struct inode_operations shmem_special_inode_operations = {
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
.setattr = shmem_setattr,
--
2.5.0
--
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