From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752633AbcFVMZp (ORCPT ); Wed, 22 Jun 2016 08:25:45 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:22147 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751434AbcFVMZn (ORCPT ); Wed, 22 Jun 2016 08:25:43 -0400 X-IBM-Helo: d01dlp03.pok.ibm.com X-IBM-MailFrom: groug@kaod.org Subject: [PATCH 1/3] fs/9p: fix create-unlink-getattr idiom From: Greg Kurz To: Eric Van Hensbergen Cc: Latchesar Ionkov , Dominique Martinet , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, v9fs-developer@lists.sourceforge.net, Ron Minnich , "David S. Miller" Date: Wed, 22 Jun 2016 14:25:33 +0200 In-Reply-To: <146659832556.15781.17414806975641516683.stgit@bahia.lan> References: <146659832556.15781.17414806975641516683.stgit@bahia.lan> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16062212-0056-0000-0000-000000973181 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16062212-0057-0000-0000-000004B09C33 Message-Id: <146659833390.15781.17019447863817814499.stgit@bahia.lan> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-22_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1606220132 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Van Hensbergen Fixes several outstanding bug reports of not being able to getattr from an open file after an unlink. This patch cleans up transient fids on an unlink and will search open fids on a client if it detects a dentry that appears to have been unlinked. This search is necessary because fstat does not pass fd information through the VFS API to the filesystem, only the dentry which for 9p has an imperfect match to fids. Inherent in this patch is also a fix for the qid handling on create/open which apparently wasn't being set correctly and was necessary for the search to succeed. A possible optimization over this fix is to include accounting of open fids with the inode in the private data (in a similar fashion to the way we track transient fids with dentries). This would allow a much quicker search for a matching open fid. Signed-off-by: Eric Van Hensbergen (changed v9fs_fid_find_global to v9fs_fid_find_inode in comment) Signed-off-by: Greg Kurz --- fs/9p/fid.c | 30 ++++++++++++++++++++++++++++++ fs/9p/vfs_inode.c | 4 ++++ net/9p/client.c | 5 ++++- 3 files changed, 38 insertions(+), 1 deletion(-) diff --git a/fs/9p/fid.c b/fs/9p/fid.c index 47db55aee7f2..e6f81f327407 100644 --- a/fs/9p/fid.c +++ b/fs/9p/fid.c @@ -54,6 +54,33 @@ void v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid) } /** + * v9fs_fid_find_inode - search for a fid off of the client list + * @inode: return a fid pointing to a specific inode + * @uid: return a fid belonging to the specified user + * + */ + +static struct p9_fid *v9fs_fid_find_inode(struct inode *inode, kuid_t uid) +{ + struct p9_client *clnt = v9fs_inode2v9ses(inode)->clnt; + struct p9_fid *fid, *fidptr, *ret = NULL; + unsigned long flags; + + p9_debug(P9_DEBUG_VFS, " inode: %p\n", inode); + + spin_lock_irqsave(&clnt->lock, flags); + list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) { + if (uid_eq(fid->uid, uid) && + (inode->i_ino == v9fs_qid2ino(&fid->qid))) { + ret = fid; + break; + } + } + spin_unlock_irqrestore(&clnt->lock, flags); + return ret; +} + +/** * v9fs_fid_find - retrieve a fid that belongs to the specified uid * @dentry: dentry to look for fid in * @uid: return fid that belongs to the specified user @@ -80,6 +107,9 @@ static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any) } } spin_unlock(&dentry->d_lock); + } else { + if (dentry->d_inode) + ret = v9fs_fid_find_inode(dentry->d_inode, uid); } return ret; diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index f4645c515262..729144ad0c2c 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -624,6 +624,10 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) v9fs_invalidate_inode_attr(inode); v9fs_invalidate_inode_attr(dir); + + /* invalidate all fids associated with dentry */ + /* NOTE: This will not include open fids */ + dentry->d_op->d_release(dentry); } return retval; } diff --git a/net/9p/client.c b/net/9p/client.c index 3fc94a49ccd5..98980bacefd4 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1208,7 +1208,7 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, if (nwname) memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid)); else - fid->qid = oldfid->qid; + memmove(&fid->qid, &oldfid->qid, sizeof(struct p9_qid)); kfree(wqids); return fid; @@ -1261,6 +1261,7 @@ int p9_client_open(struct p9_fid *fid, int mode) p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN", qid.type, (unsigned long long)qid.path, qid.version, iounit); + memmove(&fid->qid, &qid, sizeof(struct p9_qid)); fid->mode = mode; fid->iounit = iounit; @@ -1306,6 +1307,7 @@ int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode, (unsigned long long)qid->path, qid->version, iounit); + memmove(&ofid->qid, qid, sizeof(struct p9_qid)); ofid->mode = mode; ofid->iounit = iounit; @@ -1351,6 +1353,7 @@ int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode, (unsigned long long)qid.path, qid.version, iounit); + memmove(&fid->qid, &qid, sizeof(struct p9_qid)); fid->mode = mode; fid->iounit = iounit;