Srinivasa Ds 7ef55b8a05 [PATCH] NFS4: fix for recursive locking problem ... When I was performing some operations on NFS, I got below error on server side. ============================================= [ INFO: possible recursive locking detected ] 2.6.19-prep #1 --------------------------------------------- nfsd4/3525 is trying to acquire lock: (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24 but task is already holding lock: (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24 other info that might help us debug this: 2 locks held by nfsd4/3525: #0: (client_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24 #1: (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24 stack backtrace: [<c04051ed>] show_trace_log_lvl+0x58/0x16a [<c04057fa>] show_trace+0xd/0x10 [<c0405913>] dump_stack+0x19/0x1b [<c043b6f1>] __lock_acquire+0x778/0x99c [<c043be86>] lock_acquire+0x4b/0x6d [<c0611ceb>] __mutex_lock_slowpath+0xbc/0x20a [<c0611e5a>] mutex_lock+0x21/0x24 [<c047fd7e>] vfs_rmdir+0x76/0xf8 [<f94b7ce9>] nfsd4_clear_clid_dir+0x2c/0x41 [nfsd] [<f94b7de9>] nfsd4_remove_clid_dir+0xb1/0xe8 [nfsd] [<f94b307b>] laundromat_main+0x9b/0x1c3 [nfsd] [<c04333d6>] run_workqueue+0x7a/0xbb [<c0433d0b>] worker_thread+0xd2/0x107 [<c0436285>] kthread+0xc3/0xf2 [<c0402005>] kernel_thread_helper+0x5/0xb =================================================================== Cause for this problem was,2 successive mutex_lock calls on 2 diffrent inodes ,as shown below static int nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry) { int status; /* For now this directory should already be empty, but we empty it of * any regular files anyway, just in case the directory was created by * a kernel from the future.... */ nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file); mutex_lock(&dir->d_inode->i_mutex); status = vfs_rmdir(dir->d_inode, dentry); ... int vfs_rmdir(struct inode *dir, struct dentry *dentry) { int error = may_delete(dir, dentry, 1); if (error) return error; if (!dir->i_op || !dir->i_op->rmdir) return -EPERM; DQUOT_INIT(dir); mutex_lock(&dentry->d_inode->i_mutex); ... So I have developed the patch to overcome this problem. Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>		2006-11-03 12:27:57 -08:00
..
auth.c	[PATCH] knfsd: nfsd: nfsd_setuser doesn't really need to modify rqstp->rq_cred.	2006-04-11 06:18:52 -07:00
export.c	[PATCH] nfsd: misc endianness annotations	2006-10-20 10:26:43 -07:00
lockd.c	[PATCH] nfsd: misc endianness annotations	2006-10-20 10:26:43 -07:00
Makefile	[PATCH] knfsd: nfsd4: reboot hash	2005-06-24 00:06:33 -07:00
nfs2acl.c	[PATCH] nfsd: NFSv{2,3} trivial endianness annotations for error values	2006-10-20 10:26:42 -07:00
nfs3acl.c	[PATCH] nfsd: NFSv{2,3} trivial endianness annotations for error values	2006-10-20 10:26:42 -07:00
nfs3proc.c	[PATCH] nfsd: NFSv{2,3} trivial endianness annotations for error values	2006-10-20 10:26:42 -07:00
nfs3xdr.c	[PATCH] xdr annotations: NFSv3 server	2006-10-20 10:26:41 -07:00
nfs4acl.c	[PATCH] knfsd: nfsd4: acls: fix handling of zero-length acls	2006-10-04 07:55:20 -07:00
nfs4callback.c	[PATCH] nfsd: misc endianness annotations	2006-10-20 10:26:43 -07:00
nfs4idmap.c	[PATCH] fs: Conversions from kmalloc+memset to k(z|c)alloc	2006-09-27 08:26:10 -07:00
nfs4proc.c	[PATCH] nfsd: nfs_replay_me	2006-10-20 10:26:43 -07:00
nfs4recover.c	[PATCH] NFS4: fix for recursive locking problem	2006-11-03 12:27:57 -08:00
nfs4state.c	[PATCH] nfsd: nfs_replay_me	2006-10-20 10:26:43 -07:00
nfs4xdr.c	[PATCH] nfsd: NFSv4 errno endianness annotations	2006-10-20 10:26:43 -07:00
nfscache.c	[PATCH] nfsd: misc endianness annotations	2006-10-20 10:26:43 -07:00
nfsctl.c	[PATCH] knfsd: Allow max size of NFSd payload to be configured	2006-10-04 07:55:16 -07:00
nfsfh.c	[PATCH] nfsfh simple endianness annotations	2006-10-20 10:26:41 -07:00
nfsproc.c	[PATCH] nfsd: NFSv{2,3} trivial endianness annotations for error values	2006-10-20 10:26:42 -07:00
nfssvc.c	[PATCH] nfsd: misc endianness annotations	2006-10-20 10:26:43 -07:00
nfsxdr.c	[PATCH] xdr annotations: NFSv2 server	2006-10-20 10:26:41 -07:00
stats.c	[PATCH] knfsd: nfsd4: add per-operation server stats	2006-07-10 13:24:27 -07:00
vfs.c	[PATCH] nfsd: vfs.c endianness annotations	2006-10-20 10:26:41 -07:00