btrfs: refactor btrfs_set_props to validate externally

In preparation to merge multiple transactions when setting the
compression flags, split btrfs_set_props() validation part outside of
it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

4 files changed, 26 insertions, 6 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7755b503b348..3f9263ddeff8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -284,6 +284,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
                 binode->flags &= ~BTRFS_INODE_COMPRESS;
                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 
+                /* set no-compression no need to validate prop here */
                 ret = btrfs_set_prop_trans(inode, "btrfs.compression", NULL,
                                            0, 0);
                 if (ret && ret != -ENODATA)
@@ -299,6 +300,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
                 binode->flags |= BTRFS_INODE_COMPRESS;
                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 
+                /* compress_type is already validated during mount options */
                 comp = btrfs_compress_type2str(fs_info->compress_type);
                 if (!comp || comp[0] == 0)
                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
@@ -309,6 +311,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
                         goto out_drop;
 
         } else {
+                /* reset prop, no need of validate prop here */
                 ret = btrfs_set_prop_trans(inode, "btrfs.compression", NULL,
                                            0, 0);
                 if (ret && ret != -ENODATA)
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index 44b7bf647ab3..e356dd2a0f73 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -55,6 +55,23 @@ find_prop_handler(const char *name,
         return NULL;
 }
 
+int btrfs_validate_prop(const char *name, const char *value, size_t value_len)
+{
+        const struct prop_handler *handler;
+
+        if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
+                return -EINVAL;
+
+        handler = find_prop_handler(name, NULL);
+        if (!handler)
+                return -EINVAL;
+
+        if (value_len == 0)
+                return 0;
+
+        return handler->validate(value, value_len);
+}
+
 static int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
                           const char *name, const char *value, size_t value_len,
                           int flags)
@@ -62,9 +79,6 @@ static int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
         const struct prop_handler *handler;
         int ret;
 
-        if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
-                return -EINVAL;
-
         handler = find_prop_handler(name, NULL);
         if (!handler)
                 return -EINVAL;
@@ -85,9 +99,6 @@ static int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
                 return ret;
         }
 
-        ret = handler->validate(value, value_len);
-        if (ret)
-                return ret;
         if (trans)
                 ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
                                      value_len, flags);
diff --git a/fs/btrfs/props.h b/fs/btrfs/props.h
index b1a6b233b774..01d2c1899bc7 100644
--- a/fs/btrfs/props.h
+++ b/fs/btrfs/props.h
@@ -12,6 +12,7 @@ void __init btrfs_props_init(void);
 
 int btrfs_set_prop_trans(struct inode *inode, const char *name,
                          const char *value, size_t value_len, int flags);
+int btrfs_validate_prop(const char *name, const char *value, size_t value_len);
 
 int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path);
 
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index cb45c02cdc44..09db8f5f08fe 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -371,7 +371,12 @@ static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
                                         const char *name, const void *value,
                                         size_t size, int flags)
 {
+        int ret;
+
         name = xattr_full_name(handler, name);
+        ret = btrfs_validate_prop(name, value, size);
+        if (ret)
+                return ret;
         return btrfs_set_prop_trans(inode, name, value, size, flags);
 }