Btrfs: make sure reserve_metadata_bytes doesn't leak out strange errors

[~andy/linux] / fs / btrfs / xattr.c

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index a5303b871b13874d574edb6dec5642cf2286e7cb..d733b9cfea343207e71bdb6d8d8b51323717c800 100644 (file)
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -44,7 +44,7 @@ ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
                return -ENOMEM;
 
        /* lookup the xattr by name */
-       di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
+       di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
                                strlen(name), 0);
        if (!di) {
                ret = -ENODATA;
@@ -102,43 +102,57 @@ static int do_setxattr(struct btrfs_trans_handle *trans,
        if (!path)
                return -ENOMEM;
 
-       /* first lets see if we already have this xattr */
-       di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
-                               strlen(name), -1);
-       if (IS_ERR(di)) {
-               ret = PTR_ERR(di);
-               goto out;
+       if (flags & XATTR_REPLACE) {
+               di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
+                                       name_len, -1);
+               if (IS_ERR(di)) {
+                       ret = PTR_ERR(di);
+                       goto out;
+               } else if (!di) {
+                       ret = -ENODATA;
+                       goto out;
+               }
+               ret = btrfs_delete_one_dir_name(trans, root, path, di);
+               if (ret)
+                       goto out;
+               btrfs_release_path(path);
        }
 
-       /* ok we already have this xattr, lets remove it */
-       if (di) {
-               /* if we want create only exit */
-               if (flags & XATTR_CREATE) {
-                       ret = -EEXIST;
+again:
+       ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
+                                     name, name_len, value, size);
+       if (ret == -EEXIST) {
+               if (flags & XATTR_CREATE)
                        goto out;
+               /*
+                * We can't use the path we already have since we won't have the
+                * proper locking for a delete, so release the path and
+                * re-lookup to delete the thing.
+                */
+               btrfs_release_path(path);
+               di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
+                                       name, name_len, -1);
+               if (IS_ERR(di)) {
+                       ret = PTR_ERR(di);
+                       goto out;
+               } else if (!di) {
+                       /* Shouldn't happen but just in case... */
+                       btrfs_release_path(path);
+                       goto again;
                }
 
                ret = btrfs_delete_one_dir_name(trans, root, path, di);
-               BUG_ON(ret);
-               btrfs_release_path(root, path);
-
-               /* if we don't have a value then we are removing the xattr */
-               if (!value)
+               if (ret)
                        goto out;
-       } else {
-               btrfs_release_path(root, path);
 
-               if (flags & XATTR_REPLACE) {
-                       /* we couldn't find the attr to replace */
-                       ret = -ENODATA;
-                       goto out;
+               /*
+                * We have a value to set, so go back and try to insert it now.
+                */
+               if (value) {
+                       btrfs_release_path(path);
+                       goto again;
                }
        }
-
-       /* ok we have to create a completely new xattr */
-       ret = btrfs_insert_xattr_item(trans, root, path, inode->i_ino,
-                                     name, name_len, value, size);
-       BUG_ON(ret);
 out:
        btrfs_free_path(path);
        return ret;
@@ -158,8 +172,6 @@ int __btrfs_setxattr(struct btrfs_trans_handle *trans,
        if (IS_ERR(trans))
                return PTR_ERR(trans);
 
-       btrfs_set_trans_block_group(trans, inode);
-
        ret = do_setxattr(trans, inode, name, value, size, flags);
        if (ret)
                goto out;
@@ -180,18 +192,17 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
        struct btrfs_path *path;
        struct extent_buffer *leaf;
        struct btrfs_dir_item *di;
-       int ret = 0, slot, advance;
+       int ret = 0, slot;
        size_t total_size = 0, size_left = size;
        unsigned long name_ptr;
        size_t name_len;
-       u32 nritems;
 
        /*
         * ok we want all objects associated with this id.
         * NOTE: we set key.offset = 0; because we want to start with the
         * first xattr that we find and walk forward
         */
-       key.objectid = inode->i_ino;
+       key.objectid = btrfs_ino(inode);
        btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
        key.offset = 0;
 
@@ -204,34 +215,24 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
        if (ret < 0)
                goto err;
-       advance = 0;
+
        while (1) {
                leaf = path->nodes[0];
-               nritems = btrfs_header_nritems(leaf);
                slot = path->slots[0];
 
                /* this is where we start walking through the path */
-               if (advance || slot >= nritems) {
+               if (slot >= btrfs_header_nritems(leaf)) {
                        /*
                         * if we've reached the last slot in this leaf we need
                         * to go to the next leaf and reset everything
                         */
-                       if (slot >= nritems-1) {
-                               ret = btrfs_next_leaf(root, path);
-                               if (ret)
-                                       break;
-                               leaf = path->nodes[0];
-                               nritems = btrfs_header_nritems(leaf);
-                               slot = path->slots[0];
-                       } else {
-                               /*
-                                * just walking through the slots on this leaf
-                                */
-                               slot++;
-                               path->slots[0]++;
-                       }
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret < 0)
+                               goto err;
+                       else if (ret > 0)
+                               break;
+                       continue;
                }
-               advance = 1;
 
                btrfs_item_key_to_cpu(leaf, &found_key, slot);
 
@@ -250,7 +251,7 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
                /* we are just looking for how big our buffer needs to be */
                if (!size)
-                       continue;
+                       goto next;
 
                if (!buffer || (name_len + 1) > size_left) {
                        ret = -ERANGE;
@@ -263,6 +264,8 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
                size_left -= name_len + 1;
                buffer += name_len + 1;
+next:
+               path->slots[0]++;
        }
        ret = total_size;