From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>, Neil Brown <neilb@suse.de>,
arjan <arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>
Subject: [PATCH] nfsd: lockdep annotation
Date: Wed, 23 Aug 2006 12:48:32 +0200 [thread overview]
Message-ID: <1156330112.3382.34.camel@twins> (raw)
Hi,
while doing a kernel make modules_install install over an NFS mount.
(
=============================================
[ INFO: possible recursive locking detected ]
---------------------------------------------
nfsd/9550 is trying to acquire lock:
(&inode->i_mutex){--..}, at: [<c034c845>] mutex_lock+0x1c/0x1f
but task is already holding lock:
(&inode->i_mutex){--..}, at: [<c034c845>] mutex_lock+0x1c/0x1f
other info that might help us debug this:
2 locks held by nfsd/9550:
#0: (hash_sem){..--}, at: [<cc895223>] exp_readlock+0xd/0xf [nfsd]
#1: (&inode->i_mutex){--..}, at: [<c034c845>] mutex_lock+0x1c/0x1f
stack backtrace:
[<c0103508>] show_trace_log_lvl+0x58/0x152
[<c0103b8b>] show_trace+0xd/0x10
[<c0103c2f>] dump_stack+0x19/0x1b
[<c012aa57>] __lock_acquire+0x77a/0x9a3
[<c012af4a>] lock_acquire+0x60/0x80
[<c034c6c2>] __mutex_lock_slowpath+0xa7/0x20e
[<c034c845>] mutex_lock+0x1c/0x1f
[<c0162edc>] vfs_unlink+0x34/0x8a
[<cc891d98>] nfsd_unlink+0x18f/0x1e2 [nfsd]
[<cc89884f>] nfsd3_proc_remove+0x95/0xa2 [nfsd]
[<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
[<c033e84d>] svc_process+0x3a5/0x5ed
[<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
[<c0101005>] kernel_thread_helper+0x5/0xb
DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
Leftover inexact backtrace:
[<c0103b8b>] show_trace+0xd/0x10
[<c0103c2f>] dump_stack+0x19/0x1b
[<c012aa57>] __lock_acquire+0x77a/0x9a3
[<c012af4a>] lock_acquire+0x60/0x80
[<c034c6c2>] __mutex_lock_slowpath+0xa7/0x20e
[<c034c845>] mutex_lock+0x1c/0x1f
[<c0162edc>] vfs_unlink+0x34/0x8a
[<cc891d98>] nfsd_unlink+0x18f/0x1e2 [nfsd]
[<cc89884f>] nfsd3_proc_remove+0x95/0xa2 [nfsd]
[<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
[<c033e84d>] svc_process+0x3a5/0x5ed
[<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
[<c0101005>] kernel_thread_helper+0x5/0xb
=============================================
[ INFO: possible recursive locking detected ]
---------------------------------------------
nfsd/9580 is trying to acquire lock:
(&inode->i_mutex){--..}, at: [<c034cc1d>] mutex_lock+0x1c/0x1f
but task is already holding lock:
(&inode->i_mutex){--..}, at: [<c034cc1d>] mutex_lock+0x1c/0x1f
other info that might help us debug this:
2 locks held by nfsd/9580:
#0: (hash_sem){..--}, at: [<cc89522b>] exp_readlock+0xd/0xf [nfsd]
#1: (&inode->i_mutex){--..}, at: [<c034cc1d>] mutex_lock+0x1c/0x1f
stack backtrace:
[<c0103508>] show_trace_log_lvl+0x58/0x152
[<c0103b8b>] show_trace+0xd/0x10
[<c0103c2f>] dump_stack+0x19/0x1b
[<c012aa63>] __lock_acquire+0x77a/0x9a3
[<c012af56>] lock_acquire+0x60/0x80
[<c034ca9a>] __mutex_lock_slowpath+0xa7/0x20e
[<c034cc1d>] mutex_lock+0x1c/0x1f
[<cc892ad1>] nfsd_setattr+0x2c8/0x499 [nfsd]
[<cc893ede>] nfsd_create_v3+0x31b/0x4ac [nfsd]
[<cc8984a1>] nfsd3_proc_create+0x128/0x138 [nfsd]
[<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
[<c033ec1d>] svc_process+0x3a5/0x5ed
[<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
[<c0101005>] kernel_thread_helper+0x5/0xb
DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
Leftover inexact backtrace:
[<c0103b8b>] show_trace+0xd/0x10
[<c0103c2f>] dump_stack+0x19/0x1b
[<c012aa63>] __lock_acquire+0x77a/0x9a3
[<c012af56>] lock_acquire+0x60/0x80
[<c034ca9a>] __mutex_lock_slowpath+0xa7/0x20e
[<c034cc1d>] mutex_lock+0x1c/0x1f
[<cc892ad1>] nfsd_setattr+0x2c8/0x499 [nfsd]
[<cc893ede>] nfsd_create_v3+0x31b/0x4ac [nfsd]
[<cc8984a1>] nfsd3_proc_create+0x128/0x138 [nfsd]
[<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
[<c033ec1d>] svc_process+0x3a5/0x5ed
[<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
[<c0101005>] kernel_thread_helper+0x5/0xb
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
fs/nfsd/vfs.c | 8 ++++----
include/linux/nfsd/nfsfh.h | 11 +++++++++--
2 files changed, 13 insertions(+), 6 deletions(-)
Index: linux-2.6/fs/nfsd/vfs.c
===================================================================
--- linux-2.6.orig/fs/nfsd/vfs.c
+++ linux-2.6/fs/nfsd/vfs.c
@@ -1114,7 +1114,7 @@ nfsd_create(struct svc_rqst *rqstp, stru
*/
if (!resfhp->fh_dentry) {
/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
- fh_lock(fhp);
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
dchild = lookup_one_len(fname, dentry, flen);
err = PTR_ERR(dchild);
if (IS_ERR(dchild))
@@ -1240,7 +1240,7 @@ nfsd_create_v3(struct svc_rqst *rqstp, s
err = nfserr_notdir;
if(!dirp->i_op || !dirp->i_op->lookup)
goto out;
- fh_lock(fhp);
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
/*
* Compose the response file handle.
@@ -1494,7 +1494,7 @@ nfsd_link(struct svc_rqst *rqstp, struct
if (isdotent(name, len))
goto out;
- fh_lock(ffhp);
+ fh_lock_nested(ffhp, I_MUTEX_PARENT);
ddir = ffhp->fh_dentry;
dirp = ddir->d_inode;
@@ -1644,7 +1644,7 @@ nfsd_unlink(struct svc_rqst *rqstp, stru
if (err)
goto out;
- fh_lock(fhp);
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
dentry = fhp->fh_dentry;
dirp = dentry->d_inode;
Index: linux-2.6/include/linux/nfsd/nfsfh.h
===================================================================
--- linux-2.6.orig/include/linux/nfsd/nfsfh.h
+++ linux-2.6/include/linux/nfsd/nfsfh.h
@@ -296,8 +296,9 @@ fill_post_wcc(struct svc_fh *fhp)
* vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
* so, any changes here should be reflected there.
*/
+
static inline void
-fh_lock(struct svc_fh *fhp)
+fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
{
struct dentry *dentry = fhp->fh_dentry;
struct inode *inode;
@@ -316,11 +317,17 @@ fh_lock(struct svc_fh *fhp)
}
inode = dentry->d_inode;
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, subclass);
fill_pre_wcc(fhp);
fhp->fh_locked = 1;
}
+static inline void
+fh_lock(struct svc_fh *fhp)
+{
+ fh_lock_nested(fhp, I_MUTEX_NORMAL);
+}
+
/*
* Unlock a file handle/inode
*/
next reply other threads:[~2006-08-23 10:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-23 10:48 Peter Zijlstra [this message]
2006-08-24 6:12 ` Neil Brown
2006-08-24 6:54 ` Peter Zijlstra
2006-08-24 7:35 ` Arjan van de Ven
2006-08-24 7:50 ` Neil Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1156330112.3382.34.camel@twins \
--to=a.p.zijlstra@chello.nl \
--cc=akpm@osdl.org \
--cc=arjan@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=neilb@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®