From 12fd352038c037ba3a7071a2ca8597c55114abc3 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Mon, 2 Oct 2006 02:18:03 -0700
Subject: [PATCH] [PATCH] nfsd: lockdep annotation
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>
Cc: Neil Brown <neilb@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
fs/nfsd/vfs.c | 8 ++++----
include/linux/nfsd/nfsfh.h | 11 +++++++++--
2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index c9e3b5a8fe07..443ebc52e382 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1114,7 +1114,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
*/
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, struct svc_fh *fhp,
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 svc_fh *ffhp,
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, struct svc_fh *fhp, int type,
if (err)
goto out;
- fh_lock(fhp);
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
dentry = fhp->fh_dentry;
dirp = dentry->d_inode;
diff --git a/include/linux/nfsd/nfsfh.h b/include/linux/nfsd/nfsfh.h
index 31a3cb617ce0..069257ea99a0 100644
--- a/include/linux/nfsd/nfsfh.h
+++ b/include/linux/nfsd/nfsfh.h
@@ -290,8 +290,9 @@ 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;
@@ -310,11 +311,17 @@ 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
*/
--
GitLab