Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:39109 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752853Ab3ISUuj (ORCPT ); Thu, 19 Sep 2013 16:50:39 -0400 From: "J. Bruce Fields" To: Al Viro Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, jlayton@redhat.com, Dave Chinner , "J. Bruce Fields" , David Howells Subject: [PATCH 10/13] locks: break delegations on rename Date: Thu, 19 Sep 2013 16:50:34 -0400 Message-Id: <1379623837-30798-11-git-send-email-bfields@redhat.com> In-Reply-To: <1379623837-30798-1-git-send-email-bfields@redhat.com> References: <1379623837-30798-1-git-send-email-bfields@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" Cc: David Howells Acked-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/cachefiles/namei.c | 2 +- fs/namei.c | 47 +++++++++++++++++++++++++++++++++++++++++++---- fs/nfsd/vfs.c | 2 +- include/linux/fs.h | 2 +- 4 files changed, 46 insertions(+), 7 deletions(-) diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index 6846fcef..1363eae 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -396,7 +396,7 @@ try_again: cachefiles_io_error(cache, "Rename security error %d", ret); } else { ret = vfs_rename(dir->d_inode, rep, - cache->graveyard->d_inode, grave); + cache->graveyard->d_inode, grave, NULL); if (ret != 0 && ret != -ENOMEM) cachefiles_io_error(cache, "Rename failed with error %d", ret); diff --git a/fs/namei.c b/fs/namei.c index 58d3557..aafcb6c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4039,7 +4039,8 @@ out: } static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode) { struct inode *target = new_dentry->d_inode; struct inode *source = old_dentry->d_inode; @@ -4056,6 +4057,14 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) goto out; + error = try_break_deleg(source, delegated_inode); + if (error) + goto out; + if (target) { + error = try_break_deleg(target, delegated_inode); + if (error) + goto out; + } error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); if (error) goto out; @@ -4070,8 +4079,30 @@ out: return error; } +/** + * vfs_rename - rename a filesystem object + * @old_dir: parent of source + * @old_dentry: source + * @new_dir: parent of destination + * @new_dentry: destination + * @delegated_inode: returns an inode needing a delegation break + * + * The caller must hold multiple mutexes--see lock_rename()). + * + * If vfs_rename discovers a delegation in need of breaking at either + * the source or destination, it will return -EWOULDBLOCK and return a + * reference to the inode in delegated_inode. The caller should then + * break the delegation and retry. Because breaking a delegation may + * take a long time, the caller should drop all locks before doing + * so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. + */ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode) { int error; int is_dir = S_ISDIR(old_dentry->d_inode->i_mode); @@ -4099,7 +4130,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (is_dir) error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); else - error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry); + error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode); if (!error) fsnotify_move(old_dir, new_dir, old_name, is_dir, new_dentry->d_inode, old_dentry); @@ -4115,6 +4146,7 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, struct dentry *old_dentry, *new_dentry; struct dentry *trap; struct nameidata oldnd, newnd; + struct inode *delegated_inode = NULL; struct filename *from; struct filename *to; unsigned int lookup_flags = 0; @@ -4154,6 +4186,7 @@ retry: newnd.flags &= ~LOOKUP_PARENT; newnd.flags |= LOOKUP_RENAME_TARGET; +retry_deleg: trap = lock_rename(new_dir, old_dir); old_dentry = lookup_hash(&oldnd); @@ -4190,13 +4223,19 @@ retry: if (error) goto exit5; error = vfs_rename(old_dir->d_inode, old_dentry, - new_dir->d_inode, new_dentry); + new_dir->d_inode, new_dentry, + &delegated_inode); exit5: dput(new_dentry); exit4: dput(old_dentry); exit3: unlock_rename(new_dir, old_dir); + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } mnt_drop_write(oldnd.path.mnt); exit2: if (retry_estale(error, lookup_flags)) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 00d0616..680081b 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1838,7 +1838,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, if (host_err) goto out_dput_new; } - host_err = vfs_rename(fdir, odentry, tdir, ndentry); + host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL); if (!host_err) { host_err = commit_metadata(tfhp); if (!host_err) diff --git a/include/linux/fs.h b/include/linux/fs.h index 9ca64a4..f15e6ed 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1468,7 +1468,7 @@ extern int vfs_symlink(struct inode *, struct dentry *, const char *); extern int vfs_link(struct dentry *, struct inode *, struct dentry *); extern int vfs_rmdir(struct inode *, struct dentry *); extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); -extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); +extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **); /* * VFS dentry helper functions. -- 1.7.9.5