From f6de7a39c181dfb8a2c534661a53c73afb3081cd Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 4 Sep 2013 10:08:54 -0400 Subject: [PATCH] NFSv4: Document the recover_lost_locks kernel parameter Rename the new 'recover_locks' kernel parameter to 'recover_lost_locks' and change the default to 'false'. Document why in Documentation/kernel-parameters.txt Move the 'recover_lost_locks' kernel parameter to fs/nfs/super.c to make it easy to backport to kernels prior to 3.6.x, which don't have a separate NFSv4 module. Signed-off-by: Trond Myklebust --- Documentation/kernel-parameters.txt | 12 ++++++++++++ fs/nfs/nfs4_fs.h | 1 + fs/nfs/nfs4proc.c | 8 +------- fs/nfs/super.c | 8 ++++++++ 4 files changed, 22 insertions(+), 7 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 15356aca938c..30584b194984 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1847,6 +1847,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted. will be sent. The default is to send the implementation identification information. + + nfs.recover_lost_locks = + [NFSv4] Attempt to recover locks that were lost due + to a lease timeout on the server. Please note that + doing this risks data corruption, since there are + no guarantees that the file will remain unchanged + after the locks are lost. + If you want to enable the kernel legacy behaviour of + attempting to recover these locks, then set this + parameter to '1'. + The default parameter value of '0' causes the kernel + not to attempt recovery of lost locks. nfsd.nfs4_disable_idmapping= [NFSv4] When set to the default of '1', the NFSv4 diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 64118316a407..277407df6d47 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -372,6 +372,7 @@ struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct extern bool nfs4_disable_idmapping; extern unsigned short max_session_slots; extern unsigned short send_implementation_id; +extern bool recover_lost_locks; #define NFS4_CLIENT_ID_UNIQ_LEN (64) extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN]; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 1eb694e0f305..535011a27415 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5523,12 +5523,6 @@ static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request return err; } -bool recover_locks = true; -module_param(recover_locks, bool, 0644); -MODULE_PARM_DESC(recover_locks, - "If the server reports that a lock might be lost, " - "try to recovery it risking corruption."); - static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request) { struct nfs_server *server = NFS_SERVER(state->inode); @@ -5540,7 +5534,7 @@ static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request err = nfs4_set_lock_state(state, request); if (err != 0) return err; - if (!recover_locks) { + if (!recover_lost_locks) { set_bit(NFS_LOCK_LOST, &request->fl_u.nfs4_fl.owner->ls_flags); return 0; } diff --git a/fs/nfs/super.c b/fs/nfs/super.c index f2071d221c77..6ad9053d8906 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2758,6 +2758,7 @@ bool nfs4_disable_idmapping = true; unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE; unsigned short send_implementation_id = 1; char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = ""; +bool recover_lost_locks = false; EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport); EXPORT_SYMBOL_GPL(nfs_callback_tcpport); @@ -2766,6 +2767,7 @@ EXPORT_SYMBOL_GPL(nfs4_disable_idmapping); EXPORT_SYMBOL_GPL(max_session_slots); EXPORT_SYMBOL_GPL(send_implementation_id); EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier); +EXPORT_SYMBOL_GPL(recover_lost_locks); #define NFS_CALLBACK_MAXPORTNR (65535U) @@ -2803,4 +2805,10 @@ MODULE_PARM_DESC(send_implementation_id, "Send implementation ID with NFSv4.1 exchange_id"); MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string"); +module_param(recover_lost_locks, bool, 0644); +MODULE_PARM_DESC(recover_lost_locks, + "If the server reports that a lock might be lost, " + "try to recover it risking data corruption."); + + #endif /* CONFIG_NFS_V4 */