ceph: ensure prealloc_blob is in place when removing xattr (83eb26af) · Commits · 戴 / test

In __ceph_build_xattrs_blob(), if a ceph inode's extended attributes are marked dirty, all attributes recorded in its rb_tree index are formatted into a "blob" buffer. The target buffer is recorded in ceph_inode->i_xattrs.prealloc_blob, and it is expected to exist and be of sufficient size to hold the attributes. The extended attributes are marked dirty in two cases: when a new attribute is added to the inode; or when one is removed. In the former case work is done to ensure the prealloc_blob buffer is properly set up, but in the latter it is not. Change the logic in ceph_removexattr() so it matches what is done in ceph_setxattr(). Note that this is done in a way that keeps the two blocks of code nearly identical, in anticipation of a subsequent patch that encapsulates some of this logic into one or more helper routines. Signed-off-by:

Alex Elder <elder@dreamhost.com> Signed-off-by:

Sage Weil <sage@newdream.net>

fs/ceph/xattr.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -818,6 +818,7 @@ int ceph_removexattr(struct dentry dentry, const char name)
		struct ceph_vxattr_cb *vxattrs = ceph_inode_vxattrs(inode);
		int issued;
		int err;
		int required_blob_size;
		int dirty;

		if (ceph_snap(inode) != CEPH_NOSNAP)
		@@ -833,14 +834,34 @@ int ceph_removexattr(struct dentry dentry, const char name)
		return -EOPNOTSUPP;
		}

		err = -ENOMEM;
		spin_lock(&ci->i_ceph_lock);
		__build_xattrs(inode);
		retry:
		issued = __ceph_caps_issued(ci, NULL);
		dout("removexattr %p issued %s\n", inode, ceph_cap_string(issued));

		if (!(issued & CEPH_CAP_XATTR_EXCL))
		goto do_sync;

		required_blob_size = __get_required_blob_size(ci, 0, 0);

		if (!ci->i_xattrs.prealloc_blob \|\|
		required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) {
		struct ceph_buffer *blob;

		spin_unlock(&ci->i_ceph_lock);
		dout(" preaallocating new blob size=%d\n", required_blob_size);
		blob = ceph_buffer_new(required_blob_size, GFP_NOFS);
		if (!blob)
		goto out;
		spin_lock(&ci->i_ceph_lock);
		if (ci->i_xattrs.prealloc_blob)
		ceph_buffer_put(ci->i_xattrs.prealloc_blob);
		ci->i_xattrs.prealloc_blob = blob;
		goto retry;
		}

		err = __remove_xattr_by_name(ceph_inode(inode), name);
		dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);
		ci->i_xattrs.dirty = true;
		@@ -853,6 +874,7 @@ int ceph_removexattr(struct dentry dentry, const char name)
		do_sync:
		spin_unlock(&ci->i_ceph_lock);
		err = ceph_send_removexattr(dentry, name);
		out:
		return err;
		}

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